Pulsemaster 64 simple circuit use Commodore C-64 computer can provide wealth information about performance servos transmitter D E 6 R E E S R 0 T T 0 N Bernard L Stuecker 40 30 20 10 0 10 20 30 40 Ideal Servo Response Figure *1 PULSES Theyre heartbeat nearly modem RC systems Theyre used tell servo what position assume Theyre sent out transmitter serial stream channel #1 first channel #2 second until theyve transmitted After last channels sent transmit ter sends out sync pulse tell re ceiver its through starts process over again typical system length pulse varies between millisecond two milliseconds depending upon posi tion stick associated chan nel Whats millisecond Its thousandth second Its 1000 microseconds Its pretty short period time typical sevenchannel transmitter can send out pulses necessary control seven servos about 22 milliseconds /45th second cluding some time electronic house keeping receiver takes stream pulses sorts out sending #1 pulse #1 servo #2 pulse #2 servo servo examines pulse receiver just sent rotates its output arm appropriate location based upon length pulse pulse example millisec ond long servo will rotate its counterclockwise position pulse two milliseconds long servo will rotate its clockwise position pulse 15 milliseconds long servo will go its center position pulse length somewhere between arm will rotate intermediate position depending incoming pulse length what mean proportional control See Figure #1 graph what ideal servo will servos same Some have much better resolution deadband others price isnt always comrnensu rate performance areas 1000 1200 1400 1600 1800 2000 PULSE LENGTH microseconds Figure 1 Servo linearity curve curve ideal servo Notice servo out put arm 45O input pulse length 1000 microseconds output arm 45O input pulse length 2000 microseconds practical world straight line could somewhat curved depending linearity servos internal electronics us interested RC electronics pulses have always source trouble Until recently its difficult accurately measure equipment available RCers 1985 Kenneth Jesser published article Ra dio Control Modeler magazine entitled Digital Pulse Meter article de scribed build inexpensive instru ment designed accurately measure length pulses Soon after article published Ace RC started selling unit called Datamaster similar Jessers origi nal Digital Pulse Meter make Datamaster versatile Ace added built-in manually controlled pulse generator AM transmitter decoder addition internal pulse generator AM transmitter decoder Datamaster came self-contained unit could used either test individual servo transmitter have Commodore C-64 com puter knowledge electronics lit tle soldering skill can build simple inexpensive circuit will perform same tests Ace Datamaster Total cost components should der $1000 computer can used replace three individual instruments digi tal pulse meter manually controlled pulse 34 Model Aviation Figure 2 section Radio Shack experimenters circuit board text has part number soldered pins connector plugged computer Note positions lands copper traces circuit board respect pins connector generator automatic servo cycler As bonus computer can measure coming pulse length accurately original digital pulse meter can mea sure pulse length nearest microsec ond can also generate high-preci sion pulses operate test automati cally cycle servo circuit associated software about describe makes use 6526 Complex Interface Adapter chip CIA inside Commodore computer generate outgoing pulses time incom ing pulses chip has hardware timers counter circuits built allow measurement time intervals between microsecond 70 seconds mi crosecond resolution timers oper ated crystal-controlled clock ac curacy stability timers out standing Fortunately us designers Commodore C-64 computer made possible access chip through User Port back computer Because output lines comput ers User Port can employed generate very accurately timed pulses can use pulses operate servo check its resolution deadband centering end points linearityfeatures interesting sport flier crucial Pattern competitor can also use computergenerated pulses under control appro priate software cause servo very slowly creep through its range check defective spots potentiometer pot motor commutator defective spots generally manifest themselves jitter output arm servo servo slowly cycled end its travel otherand usually caused either wear corrosion dirt finds its way motor pot com puter can also rapidly automatically cy cle servo end its travel other can make servo arm move specific position under con trol operator other interesting features can implemented using computers internal pulse generator lets examine other side chip al lows computer accurately measure coming pulse length About Author Bernie Stuecker has involved RC since 1979 member Northern Virginia Radio Control Club Hes past president NVRC currently edits club newsletter Feedback has circulation about 235 copies per month Bernies electronics engineer pro fession also holds amateur radio station license call sign K4XY Hes amateur radio operator nearly 25 years enjoys photography model aviation hobbyand electronics computer programming hobby well profession FIGURE *3 5 volts1 1234567891011 0~1101 ABC0EF HJKLM U A- Ground 2N3838 PNP 47KE 122K pins H Data input receiver RED BLACK Sig Out Ground *6 MALE servo plug Figure 3 Schematic diagram havent much experience working schematic may need enlist help local electronics wizard Because its possible dam age computer make wiring error take extra care make sure circuit right FIGURE *5 Receiver Battery 48 volts I I lIli Data Output Servo FEMALE servo connector RED BLACK Gig Out Ground Ii2345878 9lo1ll2jj OiKL Figure 5 Separate battery schematic plan test heavy-duty servos may wish install independent supply power power supply inside computer good up 250 MA some larger servos could exceed rating damage December 1988 35 Data Output Servo Edge Connector Back View FEMALE servo connector Figure 4 components installed circuit board per schematic should look like wires right corner will connected servo receiver Alternate Connection Independent Battery Power Ii SLBbLY CYCLE ft SERVO RAPIDLY CYCLE ft SERVO CYCLE END-CENTER-END CYCLE IN 50 1IICROSECOND STEPS RESET UPPER/LOIR UNITS SET SERVO TO POSITION ASURE TRAISKITTER PULSE NIPTN il1SLEMSERUOiJ-QtJIT Figure 6 L software options screen Heres what youll see start program make selection menu simply press appropriate number Figure 7 R select option #7 measuring transmitter pulse length computer will display moving pointer will track movements make transmitter stick Also displayed digital read-out transmitter pulse width First would want mea sure incoming pulse length some reasons Standardizing equipment Lets say have new super transmitters mixing centering adjust ments end point adjustments exponential throw dual rates above Lets say after few months tweaking controls back transmitter things get pretty far out adjustment decide move system other plane may want set controls back factory specifications just have uniform starting point use computer measure cen ter end points transmitter chan nel readjusting channel well know certain have trans mitter adjustments back normal val ues can also quickly exacfly match two transmitters used buddy-box sys tem both instructor student have equal control throw Re-establishing settings between differ ent airplanes may have two planes operate same trans mitter need different throw centering adjustments can measure channel present setup accur ately make note measure ments can go back weeks months later re-establish same conditions determined optimum plane after transmitter has used other applications Checking stability over temperature An other use would check stability transmitter over range tempera tures perform temperature test charge up transmitter place freezer refrigerator few hours until its really cold simulates flying Min nesota January pull out freezer extend antenna fully turn Make note pulse length coming out channels Let transmitFigure 9 dont plan measure transmitter pulse length wont need make buffer amplifier circuit just test servos required solder female servo con nector directly computer plug setup can use menu options except #7 36 Model Aviation Figure 8 circuit everything hooked up except computer Never remove install connector power run risk blowing out something ter continue run coming up room temperature 20 30 minutes watch pulse length warms up Dont touch transmitter sticks during period See theres much difference between cold warm pulse length chan nel under test plan fly outside winter its good idea test entire system cold weather performance especially battery Some receivers servos have known fail cold temperatures brought equipment out warm car set up took off still warm might unpleasantly surprised something stops working no apparent re ason have observed least re ceiver quits working below 32 0F Checking stability over time check transmitter over time battery dis charges perform same test above freezing transmitter first Note pulse length transmitter first activated intervals battery runs down See theres differ encethis could explain some trim changes fly other benefits standardizing transmitter servo pulse widths manufacturers specifications exam ple transmitters set up same neutral pulse length can inter change servos receivers transmitters within systems being concerned about mixing matching equipment provided connectors mate op erating positive-pulse systems build transmitter kits repair transmitters pulse length measurement system can prove invaluable About circuit youll take look Figure #3 youll notice servo lead directly connected computer no interface just happens com puter CIA chip five-volt CMOS device generates pulses directly com patible standard RC servos No interfacing required drive servo di recfly computer arent interested measuring transmitter pulses dont need build rest circuitjust hook servo connector PC card edge connector plug computer Figure #9 Youll able use options software except Op tion #7 Measure Transmitter Pulse Length Although Commodore C-64 User Port output line has worked directly servos tested far Commodore User Port input line would work re ceivers Whether computer would work depended upon chip receiver using pulse decoder make computer work cases buf fer circuit designed condition coming signal receiver cir cuit consists two resistors PNP transistor provides gain isolation between test receiver computer buffer circuit place com puter has worked positive-pulse receiver have tested date About connector PC card edge connector labeled through 12 December 1988 37 Figure 10 pencil pointing two keys used prevent connector being installed upside down Theyre made piece plastic RC hinge mate rial CyAed place Make sure use installed properly Figure 11 find out accurately servo centers itself closely returns same end point install long pointer its output arm set up fixed pointer reference Mount servo steady position align fixed pointer the servo Se lect option #3 see closely servo returns its starting point cycles end Figure 12 Radio Shack IC experimenters board inexpensive yet rugged alternate hand-wired circuit could build circuit small box connect computer cable construction method described article simpler just reliable 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order Now fliers over world have neat inexpensive functional way protect R/C transmitters dlltr dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus Georgia 31904 404/323-2787 9am-5pm EST across top through N across bottom Notice letters G missing will fit computer either right side up upside down very careful insert properlyyou could dam age computer connecting upside down Look User Port back computer Youll see has two slots cut circuit board slots de signed mate two keys PC card edge connector responsible providing keys right location connector keys place its impossible insert connector wrong way See Figure #10 proper position ing two keysthey fit small slots between contacts con nector some reason keys arent normally supplied connector theyre almost impossible find lo cal radio store worry youll find some plastic RC hinge material cut size inserted connector care fully instant-glued place will serve ade quately other cautiondont ever plug PC card edge connector computer computer turned could get crosswise during process cause problem perhaps blowing computers internal fuse doing serious damage Building circuit circuit built 1Ath Radio Shack Experimenters Dual IC Board catalog number 276-159 see Figure #12 quarter section board cut off using Dremel tool soldered bottom row contacts PC card edge connector designed match Commodore User Port see Figure #2 edge connector has dual row con tacts 12 top 12 bottom isolated other obtained local electronics store GC Electronics part number 41-804 Amphenol part num ber 225-2-12-2-4-1-01 Cinch part num ber 251-12-30-160 use connector top bottom pins internally connected together could damage Commodore computer type con nector addition connector circuit board youll need 2N3638 PNP silicon transistor other general-purpose small signal PNP transistor specs arent critical 4700 Ohm resistor 22000 Ohm resis tor aileron extension matches radio system aileron exten sion Its convenient source male female connector have some other way coming up connectors thats OK Youll also need small amount solder wire usual small hand tools circuit board soldered directly edge connector pins per photograph Figure #2 Look carefully photo graph sure have pins connector aligned proper lands Continued page 40 38 Model Aviation 015 "~ si69 k\j wraar5a prarr r 5000r~ KVrS C0rlare- ceescrAl0 r0Od 55010 rr 500 Foaer5nOeIAflg O Iras earle is 4 fl Full Size AerObIG World Now Available n Thr 5ze MOdel Kits. TANDOF gCAL t4OUNClt4G OUR HN ANeed DeS gried Miles scale 6lpLAN 5h1 3000 5pAN A rs 15t s279~sr sier~ eOd P55 $154008 d Iuth Vas LaO e giLt Certd0rCerdrgeant Orders accelltedPersO V IANSCOVER Glow Plug Analyzers metered NI-STARTER McDaniel R/C analyzes condition glow plug time use start engine attached dualface ampmeter indicates good marginal failed plug Another innovation McDaniel R/C 1650 ma/hr recharge able battery provides 35% starting power regular nicads Dual-face ampmeter indicates plug condition attached Model 205 shown Model 201 w/charger Model 218 shown Model 217 w/charger Mode 204 020 wall stainless steel tube stainless steel spring direct connecting high temp teflon wiring beryllium copper electrode No sliding contacts corrode Positive 6-point PIgIaUCk will strip wear out 1IOV 220V AC chargers available other fine products fron McDaniel R/C see local hobby dealer contact McDaniel RIC Inc 12206 Guinevere Rd Glenn Dale MD 20769 301 464-2260 FAX 301 262-4433 Visa MC accepted take hassle out hobiry NI STARTER Palen nOV2001 & osoS ow Plug k Puen Pend NI-STOOTEOsaeo Ia0emarkof McD,nelOC Inc lO8O McDaniel RIC Inc circuit board Its easy off position clarity ease testing circuit board situated non-conven tional manner copper traces top board Should wish could build circuit small box ex tend wires computer found convenient con struction technique purposes Refer schematic diagram Figure #3 photographs guidance may need obtain assistance lo cal club electronics expert havent much experience reading schemat ics constructing electronic devices ware wiring errors could permanently damage computer especially care ful check everything twice before plug ging circuit User Port Once have parts mounted cut aileron extension half solder male female connectors circuit board per Figure #4 schematic drawing Check wiring once mis take could damage computer re quire replacement CIA chip C64 Power servo receiver taken directly Conanodore power sup ply Commodore literature says port can provide five volts up 250 mil liamperes accessory devices Some large servos will exceed current rating especially stalled cases must provide battery other separate source power servo inde pendent Commodore power supply per drawing Figure #5 could damage Commodore power supply draw excess 250 milliamperes port length time Hooking up measure incoming pulse length youll need receiver match transmitter under test Power re ceiver comes Commodore com puter supply should no problem providing required power receiv ers Ive tested have required less 50 mil liamperes current Youll have remove receiver model least un plug servo connectors battery connector receiver before start Power receiver comes back through servo lead its necessary connect switch haruess battery receiver could damage Com modore power supply leave re ceiver battery connected please remove connectors receiver before start During test youll have move leads connecting computer re ceiver servo socket channel receiver other its just easy pull receiver out model avoid fumbling inside tight quarters Once connections have made thoroughly checked plug servo servo connector plug receiver con nector channel want test Turn computer load software type LOAD PULSEMASTER8 type RUN program listing software would longer article describing sys tem Ill volunteer provide disk nominal fee cover cost disk mailer postage Its also available ready-to-use form CompuServe information near end article Operating software Once have software loaded running yopll see menu will give following options Figure #6 1 Slowly cycle servo 2 Rapidly cycle servo 3 Cycle end-center-end 4 Cycle 50 microsecond steps test ing linearity 5 Reset upper lower limits accom modate various systems 6 Set servo position 7 Measure transmitter pulse length 8 Slew servo 0 Quit select option simply enter num ber desired routine Now lets talk about what options Option #1 Slowly Cycle Servo op tion would selected servo suspected being erratic may have noticed example models control surface does smoothly follow motion transmitter stick Run routine carefully watch servo signs jitter see either jitter erratic operation likely its servo potentiometer motor fault Some servos have pots can cleaned others sealed must replaced Consult manufacturer have questions simply send suspicious servos back repairits worth cost new airplane should fail Option #2 Rapidly Cycle Servo option drives servo end its travel other Its used bura new servo few minutes see problems arise exercise servo thats sitting around unused test servo consistency using elon gated pointer connected output arm Dont overdo 30 seconds min ute should sufficient test just about servo Option #3 Cycle End-Center-End option useful want test reso lution centering servo Before option employed should use Option #5 Reset Upper Lower Limits RC system uses something other millisecond lower limit two mil liseconds upper limit Option #3 causes servo go end its normal travel other pausing momen tarily middle option becomes useful long pointer temporarily attached servo arm stationary reference pointer set up midpoint servo travel see Figure #1 1 can readily observe well servo centers have seen certain expensive coreless ser Continued page 111 40 Model Aviation Radio Technique/Myers Continued page 33 problems evident considered signif icant time comparison objec tive obtaining additional frequencies reference individuals quali fied perform tests transmitters receivers Will procedure approved FCC b will control supervise practic es persons c What packaging shipping methods used d What requirements placed upon people e Will labels placed upon transmit ters and/or receivers standardized receiver subjected major crash receiver may off frequency yet perform control placed upon previ ously accepted equipment Will AMA allow equipment assem bled repaired owner Will AMA re quire periodic tests transmitters receivers over years reference AMA Membership Man ual p 9 AMA Frequency Committee Recom mendations para 1 AMA will assume responsibility enforcement FCC regula tions will Clubs cannot afford test equipment FCC assuredly cannot pro vide enforcement other manufactur ing level good example Citizens Band ran wild very likely questions shall arise before afier implementa tion 1991 requirements What must remembered hobby participants average mod eler limited both funds time usually complies regulations imposed equipment becomes burden enjoy ment hobby will lost 1991 frequency requirements will force RC participants pay additional fees convert existing equipment buy new equipment appears trying obtain additional frequencies fliers contest field sport fliers paying right fly Myers comment AMA sought interference free frequencies replace shared frequen cies becoming unusable sport competition fliers alike due high-powered interference sharers exclusive new channels got rid high-powered sharers would appreciate presentation questions Frequency Committee re quest reply soon possible appreciation committees ef forts Myers comment copy Mr Kennedys let ter went Fred Marks FC chairman re ply went Mr Kennedy day letter received done expense Im paid AMA service nobody re imburses time materials reproduction cosrt stamp money either Pu Isemaster/Stuecker Continued page 40 vos dont seem center well some other less-expensive standard ser vos own tests see yourself servos want use Pat tern ship Option #4 Cycle SO Microsecond Steps option checks linearity servo over its entire operating range What linearity servo truly linear will move same number degrees time pulse length incremented 50 microseconds Most servos operate over one-millisecond range servo should move 20 equal-sized steps bottom limit top limit using option See Figure #1 graph ideal servo response Option #5 Reset Upper Lower Lim its software defaults standard range pulse lengths used Ace RC others millisecond 1000 mi croseconds lower limit two mil liseconds 2000 microseconds up per limit Futaba AM series however uses 81 milliseconds 181 milliseconds system limits 1310 millisec Continued page 141 December 1988 111 Editors note RC industry has begun offer RC equipment narrow band has certified independent testing laboratories FCC type acceptance meeting AMAs Guidelines 1991 oper ation Model Aviation its AMA News sec tion now regularly publishing lists such equipment first such list appeared October 1988 issue Thus ques tions being asked renders quoted George M Myers column being swered listing RMcM NEW ELECTRIC Fly Baby. great stand-way-off scale fun ship designed 05 electric power can perform take-offs touch goes aerobatics beauty yet enjoy docile slow flight easy landings Quick easy build kit includes pre cut fuselage sides tail feathers small parts hardware complete rolled plans step-by-step instructions formed landing gear windshield Electro-Combo includes kit DSC 075 Hyperthrust motor fused switch harness Tamiya connector propeller adaptor 8/4 fiberglass propeller 4 40 Span 275 Sq area 32 oz flying weight flat bottom airfoil rudder elevator motor add ailerons too HIAVEY SPECIAL COMBO PRICE $4795 YSTEMS 675 TO WER LANE BASIC KIT $24~4ORPoRATION 215-430-8645 Pu Isemaster/Stuecker Continued page 111 onds 1310 microseconds servo center Check literature system see what range pulse widths should use its other millisecond/two millisecond standard use option reset software match system re quirements Option #6 Set Servo Position option allows generate pulse known length length set num ber microseconds enter computer keyboard prevent damage servo caused excessive travel software limits range pulse widths between 500 microseconds 2500 microseconds gives error message try exceed limits servos will hit mechan ical stops certain pulse lengths within range should type pulse length greater servo can handle servo jams quickly unplug servo re type pulse length somewhere within working range servo before re connecting Deadband check want check servos deadband type number fol lowed RETURN will cause servo assume position near cen ter its travel 1500 should servos type another number slightly larger 1505 example see servo moves doesnt move youre still within servos deadband area Keep increasing number slighfly until notice servo jisst move can usually hear motor kick dif ference between last number first number typed servos deadband microseconds good servo will have tight deadband Repeat test few times Check manufacturers specs deadband see figures agree yours yours will accurate Resolution check check servos res olution secure servo stationary ob ject small vise handy tach long pointer straight piece music wire 8 10 long servos output arm Center servo above typing 1500 place stationary reference marker next end pointer Figure #11 Move servo arm other position typing 1700 exam ple type 1500 again per fect servo pointer would return exactly original position Most will off just littlethe better servo less will off Experiment few different ser vos see really better Weve found price isnt always good indica tion good resolution deadband per formance Option #7 Measure Transmitter Pulse Length option requires have receiver compatible transmitter plan test measure transmitter pulse length plug computer de sired channel receiver after discon necting other leads receiver cluding battery computer pro vides power receiver through _________________________T SERIES planes feature balsa construction Designed intermediate flyer in A-4 mind will accept 20-25 size engine luse rear exhaust angina axceptional Skyhawk performance Tha thrill jet hassles ducted fan *4000 &H Tha Proud Bird designed meet OSPRA Formula 120 rules ThIs 1/4 scale model will accept 60120 ci size engines Epoxy glees fuselage foam wing construction Full kit $150 Semi-kit also available mo wood Sia Please add 810 581 20 Tlgershark Send check MO MasterCard VISA add $3 lea add 6% esles tax Dart ExperImental two-place full sIze aircraft Top Turkey Formulal 506$55&H PARRISH AIRCRAFT 8 Scale Models ll25SW4SthTer Plantation FL 33317 December 1988 141 SPECIALISTS IN CUSTOM COX TEE DEE & REED ENGINES 020S 049 051S & 09S ALL CUSTOM & STOCK PARTS AVAILABLE INDIVIDUALLY MANY NEW PARTS FOR OLD DISCONTINUED COX ENGINES COX PROPS & GLOW HEADS COMPETITION ACCESSORIES & CUSTOMIZED K&B ENGINES ALSO COMPLETE LINE OF RACING PARTS - GLO-BEE FIREBALL & K&B PLUGS SOLID LINES RACING WHEELS QUICK FILLS ETC WE ALSO STOCK CARBON FIBER KLOTZ OIL LATEX & SILICONE FUEL TUBING PEN BLADDER MATERIALS & HARDTO-FIND HARDWARE ESPECIALLY 2-56 & 3-48 SIZES COILS CONDENSERS NGK & STITT PLUGS SILK 12 COLORS QUALITY DOPE BRUSHES 5 & 7 LOOP RUBBER BANDS KSB SEELIG & IGNITION TIMERS GAS & DIESEL FUEL TUBING TRANSISTOR IGNITION SYSTEMS RESISTOR HI-TENSION LEADS 1/2A TEXACO PLAYBOY SR KIT 1/2A TEXACO ENGINES & PARTS EVERYTHING YOU NEED FOR OLD TIMER EVENTS servo connector Turn transmitter select op tion will notice will hor izontal scale drawn computer screen calibrated milliseconds moving pointer follows motion transmitter stick see Figure #7 prefer digital read-out pulse length theres also numeric read out measuring incoming pulse length nearest microsecond option serves two purposes can used measure end points stick travel also can used see well transmit ter sticks return neutral after theyve released Let stick snap back neutral take reading slowly return stick neutral see get same reading Move stick opposite direction same good set sticks will typi cally return within few microseconds same neutral setting time either direction measurement solved problem originally thought servo linkage problem systems plane would stay trim problem finally found sticky stick transmitter didnt al ways return same spot after re leased word cautionif select Op tion #7 have receiver connected computer have receiver connected no transmitter running computer will appear lock up nor mal Whats happening computer waiting pulse come User Port get out locked-up mode hold down Run/Stop key tap Re store keys Option #8 Slew Servo allows slowly move servo through its range using arrow keys lower right side keyboard change servo output arm position moving output arm position using option given read-out near est microsecond pulse length servo receiving option can used check servo linearity have large pointer con nected servo output arm protrac tor other means accurately determin ing pointer position could plot curve pulse length horizontal axis servo rotation vertical axis servo truly linear curve plot will turn out perfectly straight line Figure #1 have about hours work $10 can build transmitter checker automated servo testing setup using handful parts inex pensive home computer dont hap pen have Commodore C-64 computer should someone within club does computerized radio/servo checker could make interesting group project something club could make available service during meet ing rainy weekend give mem bers means checking RC systems hope find useful tool Parts List 1 ea Aileron Connector match radio sys tem 1 ea PC Card Edge Connector match Com modore C64* IC Electromcs part #41-804 #41-816 Amphenol part #225-2-12-2-4-1-01 Cinch part #251-12-30-160 1 ea Experimenters Dual IC Board Radio Shack catalog #276-159 1 ea 2N3638 MPS2907 other PNP silicon general purpose small signal transistor Radio Shack catalog #276-2023 1 ea 4700 Ohm A-watt resistor Radio Shack catalog #271-1330 1 ca 22000 Ohm A-watt resistor Radio Shack Catalog #271-1339 Solder wire miscellaneous small hand tools *The cost PC card edge connector lo cal electronics dealer approximately $375 Its also listed part number 12/245E Jameco Electronics catalog costs $149 can reach Jameco Electronics 415 592-8097 write 1355 Shoreway Rd Belmont CA 94002 Janieco has $2000 minimum order may want get few friends together prepare bulk purchase Jameco also requires 5% handling fee $100 minimum Call Ja meco cant find connector locally have handful connectors Ill pro vide $500 first-come basis until supply runs out Please include pre-addressed stamped envelope orders case check has returned software project available Commodore diskette au thor CompuServe No hard copy printout available diskette can obtained sending $500 check money order cover cost disk mailer postage Bernard L Stuecker 2433 Carey Ln Vienna VA 22180 CompuServe subscribers can GO MOD ELNET find program software dowaloading Library 11 com mand BRO KEYSERVO can get CompuServe subscription information calling CompuServe 800 848-8199 AMA member would like free CompuServe subscription kit write Doug Pratt AMA HQ 1810 Samuel Morse Dr Reston VA 22090 ModelNet AMAs computer bulletin board service need information about project please sure include pre addressed stamped envelope query address above RC Soaring/Blakeslee Continued page 43 planes DG-100/428/132/229 DG-200 Acroracer/3 75/[ 106/ 128]/293 DG-200/ 428/119/257 DG-l00/428/143/250 DG 202/500/[139/16 11/216 first DG-100 now 11 years old wings DG-200 conventional con struction 2mm balsa sheeting steel blade joiners others have blue foam cores covered fiberglass obechi made using vacuum-bag technique DG-202 50 142 Model Aviation OUR REV-UP INVENTORY AVERAGES OVER 9000 PROPS I! CALL FOR IMMEDIATE SHIPMENT ON VISA OR MASTERCARD OLD TIMER SUPPLIES ORDER BY MAIL OR PHONE 619728-4365 SORRY NO COD VISA & MASTERCARD WELCOME DEALER INQUIRES INVITED MINIMUM MERCHANDISE ORDER $1000 SHIPPING & HANDLING FEE $150 E ADD $100 auinrn IAIITLJIId 2A UfI R5
Edition: Model Aviation - 1988/12
Page Numbers: 34, 35, 36, 37, 38, 40, 111, 141, 142
Pulsemaster 64 simple circuit use Commodore C-64 computer can provide wealth information about performance servos transmitter D E 6 R E E S R 0 T T 0 N Bernard L Stuecker 40 30 20 10 0 10 20 30 40 Ideal Servo Response Figure *1 PULSES Theyre heartbeat nearly modem RC systems Theyre used tell servo what position assume Theyre sent out transmitter serial stream channel #1 first channel #2 second until theyve transmitted After last channels sent transmit ter sends out sync pulse tell re ceiver its through starts process over again typical system length pulse varies between millisecond two milliseconds depending upon posi tion stick associated chan nel Whats millisecond Its thousandth second Its 1000 microseconds Its pretty short period time typical sevenchannel transmitter can send out pulses necessary control seven servos about 22 milliseconds /45th second cluding some time electronic house keeping receiver takes stream pulses sorts out sending #1 pulse #1 servo #2 pulse #2 servo servo examines pulse receiver just sent rotates its output arm appropriate location based upon length pulse pulse example millisec ond long servo will rotate its counterclockwise position pulse two milliseconds long servo will rotate its clockwise position pulse 15 milliseconds long servo will go its center position pulse length somewhere between arm will rotate intermediate position depending incoming pulse length what mean proportional control See Figure #1 graph what ideal servo will servos same Some have much better resolution deadband others price isnt always comrnensu rate performance areas 1000 1200 1400 1600 1800 2000 PULSE LENGTH microseconds Figure 1 Servo linearity curve curve ideal servo Notice servo out put arm 45O input pulse length 1000 microseconds output arm 45O input pulse length 2000 microseconds practical world straight line could somewhat curved depending linearity servos internal electronics us interested RC electronics pulses have always source trouble Until recently its difficult accurately measure equipment available RCers 1985 Kenneth Jesser published article Ra dio Control Modeler magazine entitled Digital Pulse Meter article de scribed build inexpensive instru ment designed accurately measure length pulses Soon after article published Ace RC started selling unit called Datamaster similar Jessers origi nal Digital Pulse Meter make Datamaster versatile Ace added built-in manually controlled pulse generator AM transmitter decoder addition internal pulse generator AM transmitter decoder Datamaster came self-contained unit could used either test individual servo transmitter have Commodore C-64 com puter knowledge electronics lit tle soldering skill can build simple inexpensive circuit will perform same tests Ace Datamaster Total cost components should der $1000 computer can used replace three individual instruments digi tal pulse meter manually controlled pulse 34 Model Aviation Figure 2 section Radio Shack experimenters circuit board text has part number soldered pins connector plugged computer Note positions lands copper traces circuit board respect pins connector generator automatic servo cycler As bonus computer can measure coming pulse length accurately original digital pulse meter can mea sure pulse length nearest microsec ond can also generate high-preci sion pulses operate test automati cally cycle servo circuit associated software about describe makes use 6526 Complex Interface Adapter chip CIA inside Commodore computer generate outgoing pulses time incom ing pulses chip has hardware timers counter circuits built allow measurement time intervals between microsecond 70 seconds mi crosecond resolution timers oper ated crystal-controlled clock ac curacy stability timers out standing Fortunately us designers Commodore C-64 computer made possible access chip through User Port back computer Because output lines comput ers User Port can employed generate very accurately timed pulses can use pulses operate servo check its resolution deadband centering end points linearityfeatures interesting sport flier crucial Pattern competitor can also use computergenerated pulses under control appro priate software cause servo very slowly creep through its range check defective spots potentiometer pot motor commutator defective spots generally manifest themselves jitter output arm servo servo slowly cycled end its travel otherand usually caused either wear corrosion dirt finds its way motor pot com puter can also rapidly automatically cy cle servo end its travel other can make servo arm move specific position under con trol operator other interesting features can implemented using computers internal pulse generator lets examine other side chip al lows computer accurately measure coming pulse length About Author Bernie Stuecker has involved RC since 1979 member Northern Virginia Radio Control Club Hes past president NVRC currently edits club newsletter Feedback has circulation about 235 copies per month Bernies electronics engineer pro fession also holds amateur radio station license call sign K4XY Hes amateur radio operator nearly 25 years enjoys photography model aviation hobbyand electronics computer programming hobby well profession FIGURE *3 5 volts1 1234567891011 0~1101 ABC0EF HJKLM U A- Ground 2N3838 PNP 47KE 122K pins H Data input receiver RED BLACK Sig Out Ground *6 MALE servo plug Figure 3 Schematic diagram havent much experience working schematic may need enlist help local electronics wizard Because its possible dam age computer make wiring error take extra care make sure circuit right FIGURE *5 Receiver Battery 48 volts I I lIli Data Output Servo FEMALE servo connector RED BLACK Gig Out Ground Ii2345878 9lo1ll2jj OiKL Figure 5 Separate battery schematic plan test heavy-duty servos may wish install independent supply power power supply inside computer good up 250 MA some larger servos could exceed rating damage December 1988 35 Data Output Servo Edge Connector Back View FEMALE servo connector Figure 4 components installed circuit board per schematic should look like wires right corner will connected servo receiver Alternate Connection Independent Battery Power Ii SLBbLY CYCLE ft SERVO RAPIDLY CYCLE ft SERVO CYCLE END-CENTER-END CYCLE IN 50 1IICROSECOND STEPS RESET UPPER/LOIR UNITS SET SERVO TO POSITION ASURE TRAISKITTER PULSE NIPTN il1SLEMSERUOiJ-QtJIT Figure 6 L software options screen Heres what youll see start program make selection menu simply press appropriate number Figure 7 R select option #7 measuring transmitter pulse length computer will display moving pointer will track movements make transmitter stick Also displayed digital read-out transmitter pulse width First would want mea sure incoming pulse length some reasons Standardizing equipment Lets say have new super transmitters mixing centering adjust ments end point adjustments exponential throw dual rates above Lets say after few months tweaking controls back transmitter things get pretty far out adjustment decide move system other plane may want set controls back factory specifications just have uniform starting point use computer measure cen ter end points transmitter chan nel readjusting channel well know certain have trans mitter adjustments back normal val ues can also quickly exacfly match two transmitters used buddy-box sys tem both instructor student have equal control throw Re-establishing settings between differ ent airplanes may have two planes operate same trans mitter need different throw centering adjustments can measure channel present setup accur ately make note measure ments can go back weeks months later re-establish same conditions determined optimum plane after transmitter has used other applications Checking stability over temperature An other use would check stability transmitter over range tempera tures perform temperature test charge up transmitter place freezer refrigerator few hours until its really cold simulates flying Min nesota January pull out freezer extend antenna fully turn Make note pulse length coming out channels Let transmitFigure 9 dont plan measure transmitter pulse length wont need make buffer amplifier circuit just test servos required solder female servo con nector directly computer plug setup can use menu options except #7 36 Model Aviation Figure 8 circuit everything hooked up except computer Never remove install connector power run risk blowing out something ter continue run coming up room temperature 20 30 minutes watch pulse length warms up Dont touch transmitter sticks during period See theres much difference between cold warm pulse length chan nel under test plan fly outside winter its good idea test entire system cold weather performance especially battery Some receivers servos have known fail cold temperatures brought equipment out warm car set up took off still warm might unpleasantly surprised something stops working no apparent re ason have observed least re ceiver quits working below 32 0F Checking stability over time check transmitter over time battery dis charges perform same test above freezing transmitter first Note pulse length transmitter first activated intervals battery runs down See theres differ encethis could explain some trim changes fly other benefits standardizing transmitter servo pulse widths manufacturers specifications exam ple transmitters set up same neutral pulse length can inter change servos receivers transmitters within systems being concerned about mixing matching equipment provided connectors mate op erating positive-pulse systems build transmitter kits repair transmitters pulse length measurement system can prove invaluable About circuit youll take look Figure #3 youll notice servo lead directly connected computer no interface just happens com puter CIA chip five-volt CMOS device generates pulses directly com patible standard RC servos No interfacing required drive servo di recfly computer arent interested measuring transmitter pulses dont need build rest circuitjust hook servo connector PC card edge connector plug computer Figure #9 Youll able use options software except Op tion #7 Measure Transmitter Pulse Length Although Commodore C-64 User Port output line has worked directly servos tested far Commodore User Port input line would work re ceivers Whether computer would work depended upon chip receiver using pulse decoder make computer work cases buf fer circuit designed condition coming signal receiver cir cuit consists two resistors PNP transistor provides gain isolation between test receiver computer buffer circuit place com puter has worked positive-pulse receiver have tested date About connector PC card edge connector labeled through 12 December 1988 37 Figure 10 pencil pointing two keys used prevent connector being installed upside down Theyre made piece plastic RC hinge mate rial CyAed place Make sure use installed properly Figure 11 find out accurately servo centers itself closely returns same end point install long pointer its output arm set up fixed pointer reference Mount servo steady position align fixed pointer the servo Se lect option #3 see closely servo returns its starting point cycles end Figure 12 Radio Shack IC experimenters board inexpensive yet rugged alternate hand-wired circuit could build circuit small box connect computer cable construction method described article simpler just reliable 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order Now fliers over world have neat inexpensive functional way protect R/C transmitters dlltr dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus Georgia 31904 404/323-2787 9am-5pm EST across top through N across bottom Notice letters G missing will fit computer either right side up upside down very careful insert properlyyou could dam age computer connecting upside down Look User Port back computer Youll see has two slots cut circuit board slots de signed mate two keys PC card edge connector responsible providing keys right location connector keys place its impossible insert connector wrong way See Figure #10 proper position ing two keysthey fit small slots between contacts con nector some reason keys arent normally supplied connector theyre almost impossible find lo cal radio store worry youll find some plastic RC hinge material cut size inserted connector care fully instant-glued place will serve ade quately other cautiondont ever plug PC card edge connector computer computer turned could get crosswise during process cause problem perhaps blowing computers internal fuse doing serious damage Building circuit circuit built 1Ath Radio Shack Experimenters Dual IC Board catalog number 276-159 see Figure #12 quarter section board cut off using Dremel tool soldered bottom row contacts PC card edge connector designed match Commodore User Port see Figure #2 edge connector has dual row con tacts 12 top 12 bottom isolated other obtained local electronics store GC Electronics part number 41-804 Amphenol part num ber 225-2-12-2-4-1-01 Cinch part num ber 251-12-30-160 use connector top bottom pins internally connected together could damage Commodore computer type con nector addition connector circuit board youll need 2N3638 PNP silicon transistor other general-purpose small signal PNP transistor specs arent critical 4700 Ohm resistor 22000 Ohm resis tor aileron extension matches radio system aileron exten sion Its convenient source male female connector have some other way coming up connectors thats OK Youll also need small amount solder wire usual small hand tools circuit board soldered directly edge connector pins per photograph Figure #2 Look carefully photo graph sure have pins connector aligned proper lands Continued page 40 38 Model Aviation 015 "~ si69 k\j wraar5a prarr r 5000r~ KVrS C0rlare- ceescrAl0 r0Od 55010 rr 500 Foaer5nOeIAflg O Iras earle is 4 fl Full Size AerObIG World Now Available n Thr 5ze MOdel Kits. TANDOF gCAL t4OUNClt4G OUR HN ANeed DeS gried Miles scale 6lpLAN 5h1 3000 5pAN A rs 15t s279~sr sier~ eOd P55 $154008 d Iuth Vas LaO e giLt Certd0rCerdrgeant Orders accelltedPersO V IANSCOVER Glow Plug Analyzers metered NI-STARTER McDaniel R/C analyzes condition glow plug time use start engine attached dualface ampmeter indicates good marginal failed plug Another innovation McDaniel R/C 1650 ma/hr recharge able battery provides 35% starting power regular nicads Dual-face ampmeter indicates plug condition attached Model 205 shown Model 201 w/charger Model 218 shown Model 217 w/charger Mode 204 020 wall stainless steel tube stainless steel spring direct connecting high temp teflon wiring beryllium copper electrode No sliding contacts corrode Positive 6-point PIgIaUCk will strip wear out 1IOV 220V AC chargers available other fine products fron McDaniel R/C see local hobby dealer contact McDaniel RIC Inc 12206 Guinevere Rd Glenn Dale MD 20769 301 464-2260 FAX 301 262-4433 Visa MC accepted take hassle out hobiry NI STARTER Palen nOV2001 & osoS ow Plug k Puen Pend NI-STOOTEOsaeo Ia0emarkof McD,nelOC Inc lO8O McDaniel RIC Inc circuit board Its easy off position clarity ease testing circuit board situated non-conven tional manner copper traces top board Should wish could build circuit small box ex tend wires computer found convenient con struction technique purposes Refer schematic diagram Figure #3 photographs guidance may need obtain assistance lo cal club electronics expert havent much experience reading schemat ics constructing electronic devices ware wiring errors could permanently damage computer especially care ful check everything twice before plug ging circuit User Port Once have parts mounted cut aileron extension half solder male female connectors circuit board per Figure #4 schematic drawing Check wiring once mis take could damage computer re quire replacement CIA chip C64 Power servo receiver taken directly Conanodore power sup ply Commodore literature says port can provide five volts up 250 mil liamperes accessory devices Some large servos will exceed current rating especially stalled cases must provide battery other separate source power servo inde pendent Commodore power supply per drawing Figure #5 could damage Commodore power supply draw excess 250 milliamperes port length time Hooking up measure incoming pulse length youll need receiver match transmitter under test Power re ceiver comes Commodore com puter supply should no problem providing required power receiv ers Ive tested have required less 50 mil liamperes current Youll have remove receiver model least un plug servo connectors battery connector receiver before start Power receiver comes back through servo lead its necessary connect switch haruess battery receiver could damage Com modore power supply leave re ceiver battery connected please remove connectors receiver before start During test youll have move leads connecting computer re ceiver servo socket channel receiver other its just easy pull receiver out model avoid fumbling inside tight quarters Once connections have made thoroughly checked plug servo servo connector plug receiver con nector channel want test Turn computer load software type LOAD PULSEMASTER8 type RUN program listing software would longer article describing sys tem Ill volunteer provide disk nominal fee cover cost disk mailer postage Its also available ready-to-use form CompuServe information near end article Operating software Once have software loaded running yopll see menu will give following options Figure #6 1 Slowly cycle servo 2 Rapidly cycle servo 3 Cycle end-center-end 4 Cycle 50 microsecond steps test ing linearity 5 Reset upper lower limits accom modate various systems 6 Set servo position 7 Measure transmitter pulse length 8 Slew servo 0 Quit select option simply enter num ber desired routine Now lets talk about what options Option #1 Slowly Cycle Servo op tion would selected servo suspected being erratic may have noticed example models control surface does smoothly follow motion transmitter stick Run routine carefully watch servo signs jitter see either jitter erratic operation likely its servo potentiometer motor fault Some servos have pots can cleaned others sealed must replaced Consult manufacturer have questions simply send suspicious servos back repairits worth cost new airplane should fail Option #2 Rapidly Cycle Servo option drives servo end its travel other Its used bura new servo few minutes see problems arise exercise servo thats sitting around unused test servo consistency using elon gated pointer connected output arm Dont overdo 30 seconds min ute should sufficient test just about servo Option #3 Cycle End-Center-End option useful want test reso lution centering servo Before option employed should use Option #5 Reset Upper Lower Limits RC system uses something other millisecond lower limit two mil liseconds upper limit Option #3 causes servo go end its normal travel other pausing momen tarily middle option becomes useful long pointer temporarily attached servo arm stationary reference pointer set up midpoint servo travel see Figure #1 1 can readily observe well servo centers have seen certain expensive coreless ser Continued page 111 40 Model Aviation Radio Technique/Myers Continued page 33 problems evident considered signif icant time comparison objec tive obtaining additional frequencies reference individuals quali fied perform tests transmitters receivers Will procedure approved FCC b will control supervise practic es persons c What packaging shipping methods used d What requirements placed upon people e Will labels placed upon transmit ters and/or receivers standardized receiver subjected major crash receiver may off frequency yet perform control placed upon previ ously accepted equipment Will AMA allow equipment assem bled repaired owner Will AMA re quire periodic tests transmitters receivers over years reference AMA Membership Man ual p 9 AMA Frequency Committee Recom mendations para 1 AMA will assume responsibility enforcement FCC regula tions will Clubs cannot afford test equipment FCC assuredly cannot pro vide enforcement other manufactur ing level good example Citizens Band ran wild very likely questions shall arise before afier implementa tion 1991 requirements What must remembered hobby participants average mod eler limited both funds time usually complies regulations imposed equipment becomes burden enjoy ment hobby will lost 1991 frequency requirements will force RC participants pay additional fees convert existing equipment buy new equipment appears trying obtain additional frequencies fliers contest field sport fliers paying right fly Myers comment AMA sought interference free frequencies replace shared frequen cies becoming unusable sport competition fliers alike due high-powered interference sharers exclusive new channels got rid high-powered sharers would appreciate presentation questions Frequency Committee re quest reply soon possible appreciation committees ef forts Myers comment copy Mr Kennedys let ter went Fred Marks FC chairman re ply went Mr Kennedy day letter received done expense Im paid AMA service nobody re imburses time materials reproduction cosrt stamp money either Pu Isemaster/Stuecker Continued page 40 vos dont seem center well some other less-expensive standard ser vos own tests see yourself servos want use Pat tern ship Option #4 Cycle SO Microsecond Steps option checks linearity servo over its entire operating range What linearity servo truly linear will move same number degrees time pulse length incremented 50 microseconds Most servos operate over one-millisecond range servo should move 20 equal-sized steps bottom limit top limit using option See Figure #1 graph ideal servo response Option #5 Reset Upper Lower Lim its software defaults standard range pulse lengths used Ace RC others millisecond 1000 mi croseconds lower limit two mil liseconds 2000 microseconds up per limit Futaba AM series however uses 81 milliseconds 181 milliseconds system limits 1310 millisec Continued page 141 December 1988 111 Editors note RC industry has begun offer RC equipment narrow band has certified independent testing laboratories FCC type acceptance meeting AMAs Guidelines 1991 oper ation Model Aviation its AMA News sec tion now regularly publishing lists such equipment first such list appeared October 1988 issue Thus ques tions being asked renders quoted George M Myers column being swered listing RMcM NEW ELECTRIC Fly Baby. great stand-way-off scale fun ship designed 05 electric power can perform take-offs touch goes aerobatics beauty yet enjoy docile slow flight easy landings Quick easy build kit includes pre cut fuselage sides tail feathers small parts hardware complete rolled plans step-by-step instructions formed landing gear windshield Electro-Combo includes kit DSC 075 Hyperthrust motor fused switch harness Tamiya connector propeller adaptor 8/4 fiberglass propeller 4 40 Span 275 Sq area 32 oz flying weight flat bottom airfoil rudder elevator motor add ailerons too HIAVEY SPECIAL COMBO PRICE $4795 YSTEMS 675 TO WER LANE BASIC KIT $24~4ORPoRATION 215-430-8645 Pu Isemaster/Stuecker Continued page 111 onds 1310 microseconds servo center Check literature system see what range pulse widths should use its other millisecond/two millisecond standard use option reset software match system re quirements Option #6 Set Servo Position option allows generate pulse known length length set num ber microseconds enter computer keyboard prevent damage servo caused excessive travel software limits range pulse widths between 500 microseconds 2500 microseconds gives error message try exceed limits servos will hit mechan ical stops certain pulse lengths within range should type pulse length greater servo can handle servo jams quickly unplug servo re type pulse length somewhere within working range servo before re connecting Deadband check want check servos deadband type number fol lowed RETURN will cause servo assume position near cen ter its travel 1500 should servos type another number slightly larger 1505 example see servo moves doesnt move youre still within servos deadband area Keep increasing number slighfly until notice servo jisst move can usually hear motor kick dif ference between last number first number typed servos deadband microseconds good servo will have tight deadband Repeat test few times Check manufacturers specs deadband see figures agree yours yours will accurate Resolution check check servos res olution secure servo stationary ob ject small vise handy tach long pointer straight piece music wire 8 10 long servos output arm Center servo above typing 1500 place stationary reference marker next end pointer Figure #11 Move servo arm other position typing 1700 exam ple type 1500 again per fect servo pointer would return exactly original position Most will off just littlethe better servo less will off Experiment few different ser vos see really better Weve found price isnt always good indica tion good resolution deadband per formance Option #7 Measure Transmitter Pulse Length option requires have receiver compatible transmitter plan test measure transmitter pulse length plug computer de sired channel receiver after discon necting other leads receiver cluding battery computer pro vides power receiver through _________________________T SERIES planes feature balsa construction Designed intermediate flyer in A-4 mind will accept 20-25 size engine luse rear exhaust angina axceptional Skyhawk performance Tha thrill jet hassles ducted fan *4000 &H Tha Proud Bird designed meet OSPRA Formula 120 rules ThIs 1/4 scale model will accept 60120 ci size engines Epoxy glees fuselage foam wing construction Full kit $150 Semi-kit also available mo wood Sia Please add 810 581 20 Tlgershark Send check MO MasterCard VISA add $3 lea add 6% esles tax Dart ExperImental two-place full sIze aircraft Top Turkey Formulal 506$55&H PARRISH AIRCRAFT 8 Scale Models ll25SW4SthTer Plantation FL 33317 December 1988 141 SPECIALISTS IN CUSTOM COX TEE DEE & REED ENGINES 020S 049 051S & 09S ALL CUSTOM & STOCK PARTS AVAILABLE INDIVIDUALLY MANY NEW PARTS FOR OLD DISCONTINUED COX ENGINES COX PROPS & GLOW HEADS COMPETITION ACCESSORIES & CUSTOMIZED K&B ENGINES ALSO COMPLETE LINE OF RACING PARTS - GLO-BEE FIREBALL & K&B PLUGS SOLID LINES RACING WHEELS QUICK FILLS ETC WE ALSO STOCK CARBON FIBER KLOTZ OIL LATEX & SILICONE FUEL TUBING PEN BLADDER MATERIALS & HARDTO-FIND HARDWARE ESPECIALLY 2-56 & 3-48 SIZES COILS CONDENSERS NGK & STITT PLUGS SILK 12 COLORS QUALITY DOPE BRUSHES 5 & 7 LOOP RUBBER BANDS KSB SEELIG & IGNITION TIMERS GAS & DIESEL FUEL TUBING TRANSISTOR IGNITION SYSTEMS RESISTOR HI-TENSION LEADS 1/2A TEXACO PLAYBOY SR KIT 1/2A TEXACO ENGINES & PARTS EVERYTHING YOU NEED FOR OLD TIMER EVENTS servo connector Turn transmitter select op tion will notice will hor izontal scale drawn computer screen calibrated milliseconds moving pointer follows motion transmitter stick see Figure #7 prefer digital read-out pulse length theres also numeric read out measuring incoming pulse length nearest microsecond option serves two purposes can used measure end points stick travel also can used see well transmit ter sticks return neutral after theyve released Let stick snap back neutral take reading slowly return stick neutral see get same reading Move stick opposite direction same good set sticks will typi cally return within few microseconds same neutral setting time either direction measurement solved problem originally thought servo linkage problem systems plane would stay trim problem finally found sticky stick transmitter didnt al ways return same spot after re leased word cautionif select Op tion #7 have receiver connected computer have receiver connected no transmitter running computer will appear lock up nor mal Whats happening computer waiting pulse come User Port get out locked-up mode hold down Run/Stop key tap Re store keys Option #8 Slew Servo allows slowly move servo through its range using arrow keys lower right side keyboard change servo output arm position moving output arm position using option given read-out near est microsecond pulse length servo receiving option can used check servo linearity have large pointer con nected servo output arm protrac tor other means accurately determin ing pointer position could plot curve pulse length horizontal axis servo rotation vertical axis servo truly linear curve plot will turn out perfectly straight line Figure #1 have about hours work $10 can build transmitter checker automated servo testing setup using handful parts inex pensive home computer dont hap pen have Commodore C-64 computer should someone within club does computerized radio/servo checker could make interesting group project something club could make available service during meet ing rainy weekend give mem bers means checking RC systems hope find useful tool Parts List 1 ea Aileron Connector match radio sys tem 1 ea PC Card Edge Connector match Com modore C64* IC Electromcs part #41-804 #41-816 Amphenol part #225-2-12-2-4-1-01 Cinch part #251-12-30-160 1 ea Experimenters Dual IC Board Radio Shack catalog #276-159 1 ea 2N3638 MPS2907 other PNP silicon general purpose small signal transistor Radio Shack catalog #276-2023 1 ea 4700 Ohm A-watt resistor Radio Shack catalog #271-1330 1 ca 22000 Ohm A-watt resistor Radio Shack Catalog #271-1339 Solder wire miscellaneous small hand tools *The cost PC card edge connector lo cal electronics dealer approximately $375 Its also listed part number 12/245E Jameco Electronics catalog costs $149 can reach Jameco Electronics 415 592-8097 write 1355 Shoreway Rd Belmont CA 94002 Janieco has $2000 minimum order may want get few friends together prepare bulk purchase Jameco also requires 5% handling fee $100 minimum Call Ja meco cant find connector locally have handful connectors Ill pro vide $500 first-come basis until supply runs out Please include pre-addressed stamped envelope orders case check has returned software project available Commodore diskette au thor CompuServe No hard copy printout available diskette can obtained sending $500 check money order cover cost disk mailer postage Bernard L Stuecker 2433 Carey Ln Vienna VA 22180 CompuServe subscribers can GO MOD ELNET find program software dowaloading Library 11 com mand BRO KEYSERVO can get CompuServe subscription information calling CompuServe 800 848-8199 AMA member would like free CompuServe subscription kit write Doug Pratt AMA HQ 1810 Samuel Morse Dr Reston VA 22090 ModelNet AMAs computer bulletin board service need information about project please sure include pre addressed stamped envelope query address above RC Soaring/Blakeslee Continued page 43 planes DG-100/428/132/229 DG-200 Acroracer/3 75/[ 106/ 128]/293 DG-200/ 428/119/257 DG-l00/428/143/250 DG 202/500/[139/16 11/216 first DG-100 now 11 years old wings DG-200 conventional con struction 2mm balsa sheeting steel blade joiners others have blue foam cores covered fiberglass obechi made using vacuum-bag technique DG-202 50 142 Model Aviation OUR REV-UP INVENTORY AVERAGES OVER 9000 PROPS I! CALL FOR IMMEDIATE SHIPMENT ON VISA OR MASTERCARD OLD TIMER SUPPLIES ORDER BY MAIL OR PHONE 619728-4365 SORRY NO COD VISA & MASTERCARD WELCOME DEALER INQUIRES INVITED MINIMUM MERCHANDISE ORDER $1000 SHIPPING & HANDLING FEE $150 E ADD $100 auinrn IAIITLJIId 2A UfI R5
Edition: Model Aviation - 1988/12
Page Numbers: 34, 35, 36, 37, 38, 40, 111, 141, 142
Pulsemaster 64 simple circuit use Commodore C-64 computer can provide wealth information about performance servos transmitter D E 6 R E E S R 0 T T 0 N Bernard L Stuecker 40 30 20 10 0 10 20 30 40 Ideal Servo Response Figure *1 PULSES Theyre heartbeat nearly modem RC systems Theyre used tell servo what position assume Theyre sent out transmitter serial stream channel #1 first channel #2 second until theyve transmitted After last channels sent transmit ter sends out sync pulse tell re ceiver its through starts process over again typical system length pulse varies between millisecond two milliseconds depending upon posi tion stick associated chan nel Whats millisecond Its thousandth second Its 1000 microseconds Its pretty short period time typical sevenchannel transmitter can send out pulses necessary control seven servos about 22 milliseconds /45th second cluding some time electronic house keeping receiver takes stream pulses sorts out sending #1 pulse #1 servo #2 pulse #2 servo servo examines pulse receiver just sent rotates its output arm appropriate location based upon length pulse pulse example millisec ond long servo will rotate its counterclockwise position pulse two milliseconds long servo will rotate its clockwise position pulse 15 milliseconds long servo will go its center position pulse length somewhere between arm will rotate intermediate position depending incoming pulse length what mean proportional control See Figure #1 graph what ideal servo will servos same Some have much better resolution deadband others price isnt always comrnensu rate performance areas 1000 1200 1400 1600 1800 2000 PULSE LENGTH microseconds Figure 1 Servo linearity curve curve ideal servo Notice servo out put arm 45O input pulse length 1000 microseconds output arm 45O input pulse length 2000 microseconds practical world straight line could somewhat curved depending linearity servos internal electronics us interested RC electronics pulses have always source trouble Until recently its difficult accurately measure equipment available RCers 1985 Kenneth Jesser published article Ra dio Control Modeler magazine entitled Digital Pulse Meter article de scribed build inexpensive instru ment designed accurately measure length pulses Soon after article published Ace RC started selling unit called Datamaster similar Jessers origi nal Digital Pulse Meter make Datamaster versatile Ace added built-in manually controlled pulse generator AM transmitter decoder addition internal pulse generator AM transmitter decoder Datamaster came self-contained unit could used either test individual servo transmitter have Commodore C-64 com puter knowledge electronics lit tle soldering skill can build simple inexpensive circuit will perform same tests Ace Datamaster Total cost components should der $1000 computer can used replace three individual instruments digi tal pulse meter manually controlled pulse 34 Model Aviation Figure 2 section Radio Shack experimenters circuit board text has part number soldered pins connector plugged computer Note positions lands copper traces circuit board respect pins connector generator automatic servo cycler As bonus computer can measure coming pulse length accurately original digital pulse meter can mea sure pulse length nearest microsec ond can also generate high-preci sion pulses operate test automati cally cycle servo circuit associated software about describe makes use 6526 Complex Interface Adapter chip CIA inside Commodore computer generate outgoing pulses time incom ing pulses chip has hardware timers counter circuits built allow measurement time intervals between microsecond 70 seconds mi crosecond resolution timers oper ated crystal-controlled clock ac curacy stability timers out standing Fortunately us designers Commodore C-64 computer made possible access chip through User Port back computer Because output lines comput ers User Port can employed generate very accurately timed pulses can use pulses operate servo check its resolution deadband centering end points linearityfeatures interesting sport flier crucial Pattern competitor can also use computergenerated pulses under control appro priate software cause servo very slowly creep through its range check defective spots potentiometer pot motor commutator defective spots generally manifest themselves jitter output arm servo servo slowly cycled end its travel otherand usually caused either wear corrosion dirt finds its way motor pot com puter can also rapidly automatically cy cle servo end its travel other can make servo arm move specific position under con trol operator other interesting features can implemented using computers internal pulse generator lets examine other side chip al lows computer accurately measure coming pulse length About Author Bernie Stuecker has involved RC since 1979 member Northern Virginia Radio Control Club Hes past president NVRC currently edits club newsletter Feedback has circulation about 235 copies per month Bernies electronics engineer pro fession also holds amateur radio station license call sign K4XY Hes amateur radio operator nearly 25 years enjoys photography model aviation hobbyand electronics computer programming hobby well profession FIGURE *3 5 volts1 1234567891011 0~1101 ABC0EF HJKLM U A- Ground 2N3838 PNP 47KE 122K pins H Data input receiver RED BLACK Sig Out Ground *6 MALE servo plug Figure 3 Schematic diagram havent much experience working schematic may need enlist help local electronics wizard Because its possible dam age computer make wiring error take extra care make sure circuit right FIGURE *5 Receiver Battery 48 volts I I lIli Data Output Servo FEMALE servo connector RED BLACK Gig Out Ground Ii2345878 9lo1ll2jj OiKL Figure 5 Separate battery schematic plan test heavy-duty servos may wish install independent supply power power supply inside computer good up 250 MA some larger servos could exceed rating damage December 1988 35 Data Output Servo Edge Connector Back View FEMALE servo connector Figure 4 components installed circuit board per schematic should look like wires right corner will connected servo receiver Alternate Connection Independent Battery Power Ii SLBbLY CYCLE ft SERVO RAPIDLY CYCLE ft SERVO CYCLE END-CENTER-END CYCLE IN 50 1IICROSECOND STEPS RESET UPPER/LOIR UNITS SET SERVO TO POSITION ASURE TRAISKITTER PULSE NIPTN il1SLEMSERUOiJ-QtJIT Figure 6 L software options screen Heres what youll see start program make selection menu simply press appropriate number Figure 7 R select option #7 measuring transmitter pulse length computer will display moving pointer will track movements make transmitter stick Also displayed digital read-out transmitter pulse width First would want mea sure incoming pulse length some reasons Standardizing equipment Lets say have new super transmitters mixing centering adjust ments end point adjustments exponential throw dual rates above Lets say after few months tweaking controls back transmitter things get pretty far out adjustment decide move system other plane may want set controls back factory specifications just have uniform starting point use computer measure cen ter end points transmitter chan nel readjusting channel well know certain have trans mitter adjustments back normal val ues can also quickly exacfly match two transmitters used buddy-box sys tem both instructor student have equal control throw Re-establishing settings between differ ent airplanes may have two planes operate same trans mitter need different throw centering adjustments can measure channel present setup accur ately make note measure ments can go back weeks months later re-establish same conditions determined optimum plane after transmitter has used other applications Checking stability over temperature An other use would check stability transmitter over range tempera tures perform temperature test charge up transmitter place freezer refrigerator few hours until its really cold simulates flying Min nesota January pull out freezer extend antenna fully turn Make note pulse length coming out channels Let transmitFigure 9 dont plan measure transmitter pulse length wont need make buffer amplifier circuit just test servos required solder female servo con nector directly computer plug setup can use menu options except #7 36 Model Aviation Figure 8 circuit everything hooked up except computer Never remove install connector power run risk blowing out something ter continue run coming up room temperature 20 30 minutes watch pulse length warms up Dont touch transmitter sticks during period See theres much difference between cold warm pulse length chan nel under test plan fly outside winter its good idea test entire system cold weather performance especially battery Some receivers servos have known fail cold temperatures brought equipment out warm car set up took off still warm might unpleasantly surprised something stops working no apparent re ason have observed least re ceiver quits working below 32 0F Checking stability over time check transmitter over time battery dis charges perform same test above freezing transmitter first Note pulse length transmitter first activated intervals battery runs down See theres differ encethis could explain some trim changes fly other benefits standardizing transmitter servo pulse widths manufacturers specifications exam ple transmitters set up same neutral pulse length can inter change servos receivers transmitters within systems being concerned about mixing matching equipment provided connectors mate op erating positive-pulse systems build transmitter kits repair transmitters pulse length measurement system can prove invaluable About circuit youll take look Figure #3 youll notice servo lead directly connected computer no interface just happens com puter CIA chip five-volt CMOS device generates pulses directly com patible standard RC servos No interfacing required drive servo di recfly computer arent interested measuring transmitter pulses dont need build rest circuitjust hook servo connector PC card edge connector plug computer Figure #9 Youll able use options software except Op tion #7 Measure Transmitter Pulse Length Although Commodore C-64 User Port output line has worked directly servos tested far Commodore User Port input line would work re ceivers Whether computer would work depended upon chip receiver using pulse decoder make computer work cases buf fer circuit designed condition coming signal receiver cir cuit consists two resistors PNP transistor provides gain isolation between test receiver computer buffer circuit place com puter has worked positive-pulse receiver have tested date About connector PC card edge connector labeled through 12 December 1988 37 Figure 10 pencil pointing two keys used prevent connector being installed upside down Theyre made piece plastic RC hinge mate rial CyAed place Make sure use installed properly Figure 11 find out accurately servo centers itself closely returns same end point install long pointer its output arm set up fixed pointer reference Mount servo steady position align fixed pointer the servo Se lect option #3 see closely servo returns its starting point cycles end Figure 12 Radio Shack IC experimenters board inexpensive yet rugged alternate hand-wired circuit could build circuit small box connect computer cable construction method described article simpler just reliable 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order Now fliers over world have neat inexpensive functional way protect R/C transmitters dlltr dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus Georgia 31904 404/323-2787 9am-5pm EST across top through N across bottom Notice letters G missing will fit computer either right side up upside down very careful insert properlyyou could dam age computer connecting upside down Look User Port back computer Youll see has two slots cut circuit board slots de signed mate two keys PC card edge connector responsible providing keys right location connector keys place its impossible insert connector wrong way See Figure #10 proper position ing two keysthey fit small slots between contacts con nector some reason keys arent normally supplied connector theyre almost impossible find lo cal radio store worry youll find some plastic RC hinge material cut size inserted connector care fully instant-glued place will serve ade quately other cautiondont ever plug PC card edge connector computer computer turned could get crosswise during process cause problem perhaps blowing computers internal fuse doing serious damage Building circuit circuit built 1Ath Radio Shack Experimenters Dual IC Board catalog number 276-159 see Figure #12 quarter section board cut off using Dremel tool soldered bottom row contacts PC card edge connector designed match Commodore User Port see Figure #2 edge connector has dual row con tacts 12 top 12 bottom isolated other obtained local electronics store GC Electronics part number 41-804 Amphenol part num ber 225-2-12-2-4-1-01 Cinch part num ber 251-12-30-160 use connector top bottom pins internally connected together could damage Commodore computer type con nector addition connector circuit board youll need 2N3638 PNP silicon transistor other general-purpose small signal PNP transistor specs arent critical 4700 Ohm resistor 22000 Ohm resis tor aileron extension matches radio system aileron exten sion Its convenient source male female connector have some other way coming up connectors thats OK Youll also need small amount solder wire usual small hand tools circuit board soldered directly edge connector pins per photograph Figure #2 Look carefully photo graph sure have pins connector aligned proper lands Continued page 40 38 Model Aviation 015 "~ si69 k\j wraar5a prarr r 5000r~ KVrS C0rlare- ceescrAl0 r0Od 55010 rr 500 Foaer5nOeIAflg O Iras earle is 4 fl Full Size AerObIG World Now Available n Thr 5ze MOdel Kits. TANDOF gCAL t4OUNClt4G OUR HN ANeed DeS gried Miles scale 6lpLAN 5h1 3000 5pAN A rs 15t s279~sr sier~ eOd P55 $154008 d Iuth Vas LaO e giLt Certd0rCerdrgeant Orders accelltedPersO V IANSCOVER Glow Plug Analyzers metered NI-STARTER McDaniel R/C analyzes condition glow plug time use start engine attached dualface ampmeter indicates good marginal failed plug Another innovation McDaniel R/C 1650 ma/hr recharge able battery provides 35% starting power regular nicads Dual-face ampmeter indicates plug condition attached Model 205 shown Model 201 w/charger Model 218 shown Model 217 w/charger Mode 204 020 wall stainless steel tube stainless steel spring direct connecting high temp teflon wiring beryllium copper electrode No sliding contacts corrode Positive 6-point PIgIaUCk will strip wear out 1IOV 220V AC chargers available other fine products fron McDaniel R/C see local hobby dealer contact McDaniel RIC Inc 12206 Guinevere Rd Glenn Dale MD 20769 301 464-2260 FAX 301 262-4433 Visa MC accepted take hassle out hobiry NI STARTER Palen nOV2001 & osoS ow Plug k Puen Pend NI-STOOTEOsaeo Ia0emarkof McD,nelOC Inc lO8O McDaniel RIC Inc circuit board Its easy off position clarity ease testing circuit board situated non-conven tional manner copper traces top board Should wish could build circuit small box ex tend wires computer found convenient con struction technique purposes Refer schematic diagram Figure #3 photographs guidance may need obtain assistance lo cal club electronics expert havent much experience reading schemat ics constructing electronic devices ware wiring errors could permanently damage computer especially care ful check everything twice before plug ging circuit User Port Once have parts mounted cut aileron extension half solder male female connectors circuit board per Figure #4 schematic drawing Check wiring once mis take could damage computer re quire replacement CIA chip C64 Power servo receiver taken directly Conanodore power sup ply Commodore literature says port can provide five volts up 250 mil liamperes accessory devices Some large servos will exceed current rating especially stalled cases must provide battery other separate source power servo inde pendent Commodore power supply per drawing Figure #5 could damage Commodore power supply draw excess 250 milliamperes port length time Hooking up measure incoming pulse length youll need receiver match transmitter under test Power re ceiver comes Commodore com puter supply should no problem providing required power receiv ers Ive tested have required less 50 mil liamperes current Youll have remove receiver model least un plug servo connectors battery connector receiver before start Power receiver comes back through servo lead its necessary connect switch haruess battery receiver could damage Com modore power supply leave re ceiver battery connected please remove connectors receiver before start During test youll have move leads connecting computer re ceiver servo socket channel receiver other its just easy pull receiver out model avoid fumbling inside tight quarters Once connections have made thoroughly checked plug servo servo connector plug receiver con nector channel want test Turn computer load software type LOAD PULSEMASTER8 type RUN program listing software would longer article describing sys tem Ill volunteer provide disk nominal fee cover cost disk mailer postage Its also available ready-to-use form CompuServe information near end article Operating software Once have software loaded running yopll see menu will give following options Figure #6 1 Slowly cycle servo 2 Rapidly cycle servo 3 Cycle end-center-end 4 Cycle 50 microsecond steps test ing linearity 5 Reset upper lower limits accom modate various systems 6 Set servo position 7 Measure transmitter pulse length 8 Slew servo 0 Quit select option simply enter num ber desired routine Now lets talk about what options Option #1 Slowly Cycle Servo op tion would selected servo suspected being erratic may have noticed example models control surface does smoothly follow motion transmitter stick Run routine carefully watch servo signs jitter see either jitter erratic operation likely its servo potentiometer motor fault Some servos have pots can cleaned others sealed must replaced Consult manufacturer have questions simply send suspicious servos back repairits worth cost new airplane should fail Option #2 Rapidly Cycle Servo option drives servo end its travel other Its used bura new servo few minutes see problems arise exercise servo thats sitting around unused test servo consistency using elon gated pointer connected output arm Dont overdo 30 seconds min ute should sufficient test just about servo Option #3 Cycle End-Center-End option useful want test reso lution centering servo Before option employed should use Option #5 Reset Upper Lower Limits RC system uses something other millisecond lower limit two mil liseconds upper limit Option #3 causes servo go end its normal travel other pausing momen tarily middle option becomes useful long pointer temporarily attached servo arm stationary reference pointer set up midpoint servo travel see Figure #1 1 can readily observe well servo centers have seen certain expensive coreless ser Continued page 111 40 Model Aviation Radio Technique/Myers Continued page 33 problems evident considered signif icant time comparison objec tive obtaining additional frequencies reference individuals quali fied perform tests transmitters receivers Will procedure approved FCC b will control supervise practic es persons c What packaging shipping methods used d What requirements placed upon people e Will labels placed upon transmit ters and/or receivers standardized receiver subjected major crash receiver may off frequency yet perform control placed upon previ ously accepted equipment Will AMA allow equipment assem bled repaired owner Will AMA re quire periodic tests transmitters receivers over years reference AMA Membership Man ual p 9 AMA Frequency Committee Recom mendations para 1 AMA will assume responsibility enforcement FCC regula tions will Clubs cannot afford test equipment FCC assuredly cannot pro vide enforcement other manufactur ing level good example Citizens Band ran wild very likely questions shall arise before afier implementa tion 1991 requirements What must remembered hobby participants average mod eler limited both funds time usually complies regulations imposed equipment becomes burden enjoy ment hobby will lost 1991 frequency requirements will force RC participants pay additional fees convert existing equipment buy new equipment appears trying obtain additional frequencies fliers contest field sport fliers paying right fly Myers comment AMA sought interference free frequencies replace shared frequen cies becoming unusable sport competition fliers alike due high-powered interference sharers exclusive new channels got rid high-powered sharers would appreciate presentation questions Frequency Committee re quest reply soon possible appreciation committees ef forts Myers comment copy Mr Kennedys let ter went Fred Marks FC chairman re ply went Mr Kennedy day letter received done expense Im paid AMA service nobody re imburses time materials reproduction cosrt stamp money either Pu Isemaster/Stuecker Continued page 40 vos dont seem center well some other less-expensive standard ser vos own tests see yourself servos want use Pat tern ship Option #4 Cycle SO Microsecond Steps option checks linearity servo over its entire operating range What linearity servo truly linear will move same number degrees time pulse length incremented 50 microseconds Most servos operate over one-millisecond range servo should move 20 equal-sized steps bottom limit top limit using option See Figure #1 graph ideal servo response Option #5 Reset Upper Lower Lim its software defaults standard range pulse lengths used Ace RC others millisecond 1000 mi croseconds lower limit two mil liseconds 2000 microseconds up per limit Futaba AM series however uses 81 milliseconds 181 milliseconds system limits 1310 millisec Continued page 141 December 1988 111 Editors note RC industry has begun offer RC equipment narrow band has certified independent testing laboratories FCC type acceptance meeting AMAs Guidelines 1991 oper ation Model Aviation its AMA News sec tion now regularly publishing lists such equipment first such list appeared October 1988 issue Thus ques tions being asked renders quoted George M Myers column being swered listing RMcM NEW ELECTRIC Fly Baby. great stand-way-off scale fun ship designed 05 electric power can perform take-offs touch goes aerobatics beauty yet enjoy docile slow flight easy landings Quick easy build kit includes pre cut fuselage sides tail feathers small parts hardware complete rolled plans step-by-step instructions formed landing gear windshield Electro-Combo includes kit DSC 075 Hyperthrust motor fused switch harness Tamiya connector propeller adaptor 8/4 fiberglass propeller 4 40 Span 275 Sq area 32 oz flying weight flat bottom airfoil rudder elevator motor add ailerons too HIAVEY SPECIAL COMBO PRICE $4795 YSTEMS 675 TO WER LANE BASIC KIT $24~4ORPoRATION 215-430-8645 Pu Isemaster/Stuecker Continued page 111 onds 1310 microseconds servo center Check literature system see what range pulse widths should use its other millisecond/two millisecond standard use option reset software match system re quirements Option #6 Set Servo Position option allows generate pulse known length length set num ber microseconds enter computer keyboard prevent damage servo caused excessive travel software limits range pulse widths between 500 microseconds 2500 microseconds gives error message try exceed limits servos will hit mechan ical stops certain pulse lengths within range should type pulse length greater servo can handle servo jams quickly unplug servo re type pulse length somewhere within working range servo before re connecting Deadband check want check servos deadband type number fol lowed RETURN will cause servo assume position near cen ter its travel 1500 should servos type another number slightly larger 1505 example see servo moves doesnt move youre still within servos deadband area Keep increasing number slighfly until notice servo jisst move can usually hear motor kick dif ference between last number first number typed servos deadband microseconds good servo will have tight deadband Repeat test few times Check manufacturers specs deadband see figures agree yours yours will accurate Resolution check check servos res olution secure servo stationary ob ject small vise handy tach long pointer straight piece music wire 8 10 long servos output arm Center servo above typing 1500 place stationary reference marker next end pointer Figure #11 Move servo arm other position typing 1700 exam ple type 1500 again per fect servo pointer would return exactly original position Most will off just littlethe better servo less will off Experiment few different ser vos see really better Weve found price isnt always good indica tion good resolution deadband per formance Option #7 Measure Transmitter Pulse Length option requires have receiver compatible transmitter plan test measure transmitter pulse length plug computer de sired channel receiver after discon necting other leads receiver cluding battery computer pro vides power receiver through _________________________T SERIES planes feature balsa construction Designed intermediate flyer in A-4 mind will accept 20-25 size engine luse rear exhaust angina axceptional Skyhawk performance Tha thrill jet hassles ducted fan *4000 &H Tha Proud Bird designed meet OSPRA Formula 120 rules ThIs 1/4 scale model will accept 60120 ci size engines Epoxy glees fuselage foam wing construction Full kit $150 Semi-kit also available mo wood Sia Please add 810 581 20 Tlgershark Send check MO MasterCard VISA add $3 lea add 6% esles tax Dart ExperImental two-place full sIze aircraft Top Turkey Formulal 506$55&H PARRISH AIRCRAFT 8 Scale Models ll25SW4SthTer Plantation FL 33317 December 1988 141 SPECIALISTS IN CUSTOM COX TEE DEE & REED ENGINES 020S 049 051S & 09S ALL CUSTOM & STOCK PARTS AVAILABLE INDIVIDUALLY MANY NEW PARTS FOR OLD DISCONTINUED COX ENGINES COX PROPS & GLOW HEADS COMPETITION ACCESSORIES & CUSTOMIZED K&B ENGINES ALSO COMPLETE LINE OF RACING PARTS - GLO-BEE FIREBALL & K&B PLUGS SOLID LINES RACING WHEELS QUICK FILLS ETC WE ALSO STOCK CARBON FIBER KLOTZ OIL LATEX & SILICONE FUEL TUBING PEN BLADDER MATERIALS & HARDTO-FIND HARDWARE ESPECIALLY 2-56 & 3-48 SIZES COILS CONDENSERS NGK & STITT PLUGS SILK 12 COLORS QUALITY DOPE BRUSHES 5 & 7 LOOP RUBBER BANDS KSB SEELIG & IGNITION TIMERS GAS & DIESEL FUEL TUBING TRANSISTOR IGNITION SYSTEMS RESISTOR HI-TENSION LEADS 1/2A TEXACO PLAYBOY SR KIT 1/2A TEXACO ENGINES & PARTS EVERYTHING YOU NEED FOR OLD TIMER EVENTS servo connector Turn transmitter select op tion will notice will hor izontal scale drawn computer screen calibrated milliseconds moving pointer follows motion transmitter stick see Figure #7 prefer digital read-out pulse length theres also numeric read out measuring incoming pulse length nearest microsecond option serves two purposes can used measure end points stick travel also can used see well transmit ter sticks return neutral after theyve released Let stick snap back neutral take reading slowly return stick neutral see get same reading Move stick opposite direction same good set sticks will typi cally return within few microseconds same neutral setting time either direction measurement solved problem originally thought servo linkage problem systems plane would stay trim problem finally found sticky stick transmitter didnt al ways return same spot after re leased word cautionif select Op tion #7 have receiver connected computer have receiver connected no transmitter running computer will appear lock up nor mal Whats happening computer waiting pulse come User Port get out locked-up mode hold down Run/Stop key tap Re store keys Option #8 Slew Servo allows slowly move servo through its range using arrow keys lower right side keyboard change servo output arm position moving output arm position using option given read-out near est microsecond pulse length servo receiving option can used check servo linearity have large pointer con nected servo output arm protrac tor other means accurately determin ing pointer position could plot curve pulse length horizontal axis servo rotation vertical axis servo truly linear curve plot will turn out perfectly straight line Figure #1 have about hours work $10 can build transmitter checker automated servo testing setup using handful parts inex pensive home computer dont hap pen have Commodore C-64 computer should someone within club does computerized radio/servo checker could make interesting group project something club could make available service during meet ing rainy weekend give mem bers means checking RC systems hope find useful tool Parts List 1 ea Aileron Connector match radio sys tem 1 ea PC Card Edge Connector match Com modore C64* IC Electromcs part #41-804 #41-816 Amphenol part #225-2-12-2-4-1-01 Cinch part #251-12-30-160 1 ea Experimenters Dual IC Board Radio Shack catalog #276-159 1 ea 2N3638 MPS2907 other PNP silicon general purpose small signal transistor Radio Shack catalog #276-2023 1 ea 4700 Ohm A-watt resistor Radio Shack catalog #271-1330 1 ca 22000 Ohm A-watt resistor Radio Shack Catalog #271-1339 Solder wire miscellaneous small hand tools *The cost PC card edge connector lo cal electronics dealer approximately $375 Its also listed part number 12/245E Jameco Electronics catalog costs $149 can reach Jameco Electronics 415 592-8097 write 1355 Shoreway Rd Belmont CA 94002 Janieco has $2000 minimum order may want get few friends together prepare bulk purchase Jameco also requires 5% handling fee $100 minimum Call Ja meco cant find connector locally have handful connectors Ill pro vide $500 first-come basis until supply runs out Please include pre-addressed stamped envelope orders case check has returned software project available Commodore diskette au thor CompuServe No hard copy printout available diskette can obtained sending $500 check money order cover cost disk mailer postage Bernard L Stuecker 2433 Carey Ln Vienna VA 22180 CompuServe subscribers can GO MOD ELNET find program software dowaloading Library 11 com mand BRO KEYSERVO can get CompuServe subscription information calling CompuServe 800 848-8199 AMA member would like free CompuServe subscription kit write Doug Pratt AMA HQ 1810 Samuel Morse Dr Reston VA 22090 ModelNet AMAs computer bulletin board service need information about project please sure include pre addressed stamped envelope query address above RC Soaring/Blakeslee Continued page 43 planes DG-100/428/132/229 DG-200 Acroracer/3 75/[ 106/ 128]/293 DG-200/ 428/119/257 DG-l00/428/143/250 DG 202/500/[139/16 11/216 first DG-100 now 11 years old wings DG-200 conventional con struction 2mm balsa sheeting steel blade joiners others have blue foam cores covered fiberglass obechi made using vacuum-bag technique DG-202 50 142 Model Aviation OUR REV-UP INVENTORY AVERAGES OVER 9000 PROPS I! CALL FOR IMMEDIATE SHIPMENT ON VISA OR MASTERCARD OLD TIMER SUPPLIES ORDER BY MAIL OR PHONE 619728-4365 SORRY NO COD VISA & MASTERCARD WELCOME DEALER INQUIRES INVITED MINIMUM MERCHANDISE ORDER $1000 SHIPPING & HANDLING FEE $150 E ADD $100 auinrn IAIITLJIId 2A UfI R5
Edition: Model Aviation - 1988/12
Page Numbers: 34, 35, 36, 37, 38, 40, 111, 141, 142
Pulsemaster 64 simple circuit use Commodore C-64 computer can provide wealth information about performance servos transmitter D E 6 R E E S R 0 T T 0 N Bernard L Stuecker 40 30 20 10 0 10 20 30 40 Ideal Servo Response Figure *1 PULSES Theyre heartbeat nearly modem RC systems Theyre used tell servo what position assume Theyre sent out transmitter serial stream channel #1 first channel #2 second until theyve transmitted After last channels sent transmit ter sends out sync pulse tell re ceiver its through starts process over again typical system length pulse varies between millisecond two milliseconds depending upon posi tion stick associated chan nel Whats millisecond Its thousandth second Its 1000 microseconds Its pretty short period time typical sevenchannel transmitter can send out pulses necessary control seven servos about 22 milliseconds /45th second cluding some time electronic house keeping receiver takes stream pulses sorts out sending #1 pulse #1 servo #2 pulse #2 servo servo examines pulse receiver just sent rotates its output arm appropriate location based upon length pulse pulse example millisec ond long servo will rotate its counterclockwise position pulse two milliseconds long servo will rotate its clockwise position pulse 15 milliseconds long servo will go its center position pulse length somewhere between arm will rotate intermediate position depending incoming pulse length what mean proportional control See Figure #1 graph what ideal servo will servos same Some have much better resolution deadband others price isnt always comrnensu rate performance areas 1000 1200 1400 1600 1800 2000 PULSE LENGTH microseconds Figure 1 Servo linearity curve curve ideal servo Notice servo out put arm 45O input pulse length 1000 microseconds output arm 45O input pulse length 2000 microseconds practical world straight line could somewhat curved depending linearity servos internal electronics us interested RC electronics pulses have always source trouble Until recently its difficult accurately measure equipment available RCers 1985 Kenneth Jesser published article Ra dio Control Modeler magazine entitled Digital Pulse Meter article de scribed build inexpensive instru ment designed accurately measure length pulses Soon after article published Ace RC started selling unit called Datamaster similar Jessers origi nal Digital Pulse Meter make Datamaster versatile Ace added built-in manually controlled pulse generator AM transmitter decoder addition internal pulse generator AM transmitter decoder Datamaster came self-contained unit could used either test individual servo transmitter have Commodore C-64 com puter knowledge electronics lit tle soldering skill can build simple inexpensive circuit will perform same tests Ace Datamaster Total cost components should der $1000 computer can used replace three individual instruments digi tal pulse meter manually controlled pulse 34 Model Aviation Figure 2 section Radio Shack experimenters circuit board text has part number soldered pins connector plugged computer Note positions lands copper traces circuit board respect pins connector generator automatic servo cycler As bonus computer can measure coming pulse length accurately original digital pulse meter can mea sure pulse length nearest microsec ond can also generate high-preci sion pulses operate test automati cally cycle servo circuit associated software about describe makes use 6526 Complex Interface Adapter chip CIA inside Commodore computer generate outgoing pulses time incom ing pulses chip has hardware timers counter circuits built allow measurement time intervals between microsecond 70 seconds mi crosecond resolution timers oper ated crystal-controlled clock ac curacy stability timers out standing Fortunately us designers Commodore C-64 computer made possible access chip through User Port back computer Because output lines comput ers User Port can employed generate very accurately timed pulses can use pulses operate servo check its resolution deadband centering end points linearityfeatures interesting sport flier crucial Pattern competitor can also use computergenerated pulses under control appro priate software cause servo very slowly creep through its range check defective spots potentiometer pot motor commutator defective spots generally manifest themselves jitter output arm servo servo slowly cycled end its travel otherand usually caused either wear corrosion dirt finds its way motor pot com puter can also rapidly automatically cy cle servo end its travel other can make servo arm move specific position under con trol operator other interesting features can implemented using computers internal pulse generator lets examine other side chip al lows computer accurately measure coming pulse length About Author Bernie Stuecker has involved RC since 1979 member Northern Virginia Radio Control Club Hes past president NVRC currently edits club newsletter Feedback has circulation about 235 copies per month Bernies electronics engineer pro fession also holds amateur radio station license call sign K4XY Hes amateur radio operator nearly 25 years enjoys photography model aviation hobbyand electronics computer programming hobby well profession FIGURE *3 5 volts1 1234567891011 0~1101 ABC0EF HJKLM U A- Ground 2N3838 PNP 47KE 122K pins H Data input receiver RED BLACK Sig Out Ground *6 MALE servo plug Figure 3 Schematic diagram havent much experience working schematic may need enlist help local electronics wizard Because its possible dam age computer make wiring error take extra care make sure circuit right FIGURE *5 Receiver Battery 48 volts I I lIli Data Output Servo FEMALE servo connector RED BLACK Gig Out Ground Ii2345878 9lo1ll2jj OiKL Figure 5 Separate battery schematic plan test heavy-duty servos may wish install independent supply power power supply inside computer good up 250 MA some larger servos could exceed rating damage December 1988 35 Data Output Servo Edge Connector Back View FEMALE servo connector Figure 4 components installed circuit board per schematic should look like wires right corner will connected servo receiver Alternate Connection Independent Battery Power Ii SLBbLY CYCLE ft SERVO RAPIDLY CYCLE ft SERVO CYCLE END-CENTER-END CYCLE IN 50 1IICROSECOND STEPS RESET UPPER/LOIR UNITS SET SERVO TO POSITION ASURE TRAISKITTER PULSE NIPTN il1SLEMSERUOiJ-QtJIT Figure 6 L software options screen Heres what youll see start program make selection menu simply press appropriate number Figure 7 R select option #7 measuring transmitter pulse length computer will display moving pointer will track movements make transmitter stick Also displayed digital read-out transmitter pulse width First would want mea sure incoming pulse length some reasons Standardizing equipment Lets say have new super transmitters mixing centering adjust ments end point adjustments exponential throw dual rates above Lets say after few months tweaking controls back transmitter things get pretty far out adjustment decide move system other plane may want set controls back factory specifications just have uniform starting point use computer measure cen ter end points transmitter chan nel readjusting channel well know certain have trans mitter adjustments back normal val ues can also quickly exacfly match two transmitters used buddy-box sys tem both instructor student have equal control throw Re-establishing settings between differ ent airplanes may have two planes operate same trans mitter need different throw centering adjustments can measure channel present setup accur ately make note measure ments can go back weeks months later re-establish same conditions determined optimum plane after transmitter has used other applications Checking stability over temperature An other use would check stability transmitter over range tempera tures perform temperature test charge up transmitter place freezer refrigerator few hours until its really cold simulates flying Min nesota January pull out freezer extend antenna fully turn Make note pulse length coming out channels Let transmitFigure 9 dont plan measure transmitter pulse length wont need make buffer amplifier circuit just test servos required solder female servo con nector directly computer plug setup can use menu options except #7 36 Model Aviation Figure 8 circuit everything hooked up except computer Never remove install connector power run risk blowing out something ter continue run coming up room temperature 20 30 minutes watch pulse length warms up Dont touch transmitter sticks during period See theres much difference between cold warm pulse length chan nel under test plan fly outside winter its good idea test entire system cold weather performance especially battery Some receivers servos have known fail cold temperatures brought equipment out warm car set up took off still warm might unpleasantly surprised something stops working no apparent re ason have observed least re ceiver quits working below 32 0F Checking stability over time check transmitter over time battery dis charges perform same test above freezing transmitter first Note pulse length transmitter first activated intervals battery runs down See theres differ encethis could explain some trim changes fly other benefits standardizing transmitter servo pulse widths manufacturers specifications exam ple transmitters set up same neutral pulse length can inter change servos receivers transmitters within systems being concerned about mixing matching equipment provided connectors mate op erating positive-pulse systems build transmitter kits repair transmitters pulse length measurement system can prove invaluable About circuit youll take look Figure #3 youll notice servo lead directly connected computer no interface just happens com puter CIA chip five-volt CMOS device generates pulses directly com patible standard RC servos No interfacing required drive servo di recfly computer arent interested measuring transmitter pulses dont need build rest circuitjust hook servo connector PC card edge connector plug computer Figure #9 Youll able use options software except Op tion #7 Measure Transmitter Pulse Length Although Commodore C-64 User Port output line has worked directly servos tested far Commodore User Port input line would work re ceivers Whether computer would work depended upon chip receiver using pulse decoder make computer work cases buf fer circuit designed condition coming signal receiver cir cuit consists two resistors PNP transistor provides gain isolation between test receiver computer buffer circuit place com puter has worked positive-pulse receiver have tested date About connector PC card edge connector labeled through 12 December 1988 37 Figure 10 pencil pointing two keys used prevent connector being installed upside down Theyre made piece plastic RC hinge mate rial CyAed place Make sure use installed properly Figure 11 find out accurately servo centers itself closely returns same end point install long pointer its output arm set up fixed pointer reference Mount servo steady position align fixed pointer the servo Se lect option #3 see closely servo returns its starting point cycles end Figure 12 Radio Shack IC experimenters board inexpensive yet rugged alternate hand-wired circuit could build circuit small box connect computer cable construction method described article simpler just reliable 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order Now fliers over world have neat inexpensive functional way protect R/C transmitters dlltr dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus Georgia 31904 404/323-2787 9am-5pm EST across top through N across bottom Notice letters G missing will fit computer either right side up upside down very careful insert properlyyou could dam age computer connecting upside down Look User Port back computer Youll see has two slots cut circuit board slots de signed mate two keys PC card edge connector responsible providing keys right location connector keys place its impossible insert connector wrong way See Figure #10 proper position ing two keysthey fit small slots between contacts con nector some reason keys arent normally supplied connector theyre almost impossible find lo cal radio store worry youll find some plastic RC hinge material cut size inserted connector care fully instant-glued place will serve ade quately other cautiondont ever plug PC card edge connector computer computer turned could get crosswise during process cause problem perhaps blowing computers internal fuse doing serious damage Building circuit circuit built 1Ath Radio Shack Experimenters Dual IC Board catalog number 276-159 see Figure #12 quarter section board cut off using Dremel tool soldered bottom row contacts PC card edge connector designed match Commodore User Port see Figure #2 edge connector has dual row con tacts 12 top 12 bottom isolated other obtained local electronics store GC Electronics part number 41-804 Amphenol part num ber 225-2-12-2-4-1-01 Cinch part num ber 251-12-30-160 use connector top bottom pins internally connected together could damage Commodore computer type con nector addition connector circuit board youll need 2N3638 PNP silicon transistor other general-purpose small signal PNP transistor specs arent critical 4700 Ohm resistor 22000 Ohm resis tor aileron extension matches radio system aileron exten sion Its convenient source male female connector have some other way coming up connectors thats OK Youll also need small amount solder wire usual small hand tools circuit board soldered directly edge connector pins per photograph Figure #2 Look carefully photo graph sure have pins connector aligned proper lands Continued page 40 38 Model Aviation 015 "~ si69 k\j wraar5a prarr r 5000r~ KVrS C0rlare- ceescrAl0 r0Od 55010 rr 500 Foaer5nOeIAflg O Iras earle is 4 fl Full Size AerObIG World Now Available n Thr 5ze MOdel Kits. TANDOF gCAL t4OUNClt4G OUR HN ANeed DeS gried Miles scale 6lpLAN 5h1 3000 5pAN A rs 15t s279~sr sier~ eOd P55 $154008 d Iuth Vas LaO e giLt Certd0rCerdrgeant Orders accelltedPersO V IANSCOVER Glow Plug Analyzers metered NI-STARTER McDaniel R/C analyzes condition glow plug time use start engine attached dualface ampmeter indicates good marginal failed plug Another innovation McDaniel R/C 1650 ma/hr recharge able battery provides 35% starting power regular nicads Dual-face ampmeter indicates plug condition attached Model 205 shown Model 201 w/charger Model 218 shown Model 217 w/charger Mode 204 020 wall stainless steel tube stainless steel spring direct connecting high temp teflon wiring beryllium copper electrode No sliding contacts corrode Positive 6-point PIgIaUCk will strip wear out 1IOV 220V AC chargers available other fine products fron McDaniel R/C see local hobby dealer contact McDaniel RIC Inc 12206 Guinevere Rd Glenn Dale MD 20769 301 464-2260 FAX 301 262-4433 Visa MC accepted take hassle out hobiry NI STARTER Palen nOV2001 & osoS ow Plug k Puen Pend NI-STOOTEOsaeo Ia0emarkof McD,nelOC Inc lO8O McDaniel RIC Inc circuit board Its easy off position clarity ease testing circuit board situated non-conven tional manner copper traces top board Should wish could build circuit small box ex tend wires computer found convenient con struction technique purposes Refer schematic diagram Figure #3 photographs guidance may need obtain assistance lo cal club electronics expert havent much experience reading schemat ics constructing electronic devices ware wiring errors could permanently damage computer especially care ful check everything twice before plug ging circuit User Port Once have parts mounted cut aileron extension half solder male female connectors circuit board per Figure #4 schematic drawing Check wiring once mis take could damage computer re quire replacement CIA chip C64 Power servo receiver taken directly Conanodore power sup ply Commodore literature says port can provide five volts up 250 mil liamperes accessory devices Some large servos will exceed current rating especially stalled cases must provide battery other separate source power servo inde pendent Commodore power supply per drawing Figure #5 could damage Commodore power supply draw excess 250 milliamperes port length time Hooking up measure incoming pulse length youll need receiver match transmitter under test Power re ceiver comes Commodore com puter supply should no problem providing required power receiv ers Ive tested have required less 50 mil liamperes current Youll have remove receiver model least un plug servo connectors battery connector receiver before start Power receiver comes back through servo lead its necessary connect switch haruess battery receiver could damage Com modore power supply leave re ceiver battery connected please remove connectors receiver before start During test youll have move leads connecting computer re ceiver servo socket channel receiver other its just easy pull receiver out model avoid fumbling inside tight quarters Once connections have made thoroughly checked plug servo servo connector plug receiver con nector channel want test Turn computer load software type LOAD PULSEMASTER8 type RUN program listing software would longer article describing sys tem Ill volunteer provide disk nominal fee cover cost disk mailer postage Its also available ready-to-use form CompuServe information near end article Operating software Once have software loaded running yopll see menu will give following options Figure #6 1 Slowly cycle servo 2 Rapidly cycle servo 3 Cycle end-center-end 4 Cycle 50 microsecond steps test ing linearity 5 Reset upper lower limits accom modate various systems 6 Set servo position 7 Measure transmitter pulse length 8 Slew servo 0 Quit select option simply enter num ber desired routine Now lets talk about what options Option #1 Slowly Cycle Servo op tion would selected servo suspected being erratic may have noticed example models control surface does smoothly follow motion transmitter stick Run routine carefully watch servo signs jitter see either jitter erratic operation likely its servo potentiometer motor fault Some servos have pots can cleaned others sealed must replaced Consult manufacturer have questions simply send suspicious servos back repairits worth cost new airplane should fail Option #2 Rapidly Cycle Servo option drives servo end its travel other Its used bura new servo few minutes see problems arise exercise servo thats sitting around unused test servo consistency using elon gated pointer connected output arm Dont overdo 30 seconds min ute should sufficient test just about servo Option #3 Cycle End-Center-End option useful want test reso lution centering servo Before option employed should use Option #5 Reset Upper Lower Limits RC system uses something other millisecond lower limit two mil liseconds upper limit Option #3 causes servo go end its normal travel other pausing momen tarily middle option becomes useful long pointer temporarily attached servo arm stationary reference pointer set up midpoint servo travel see Figure #1 1 can readily observe well servo centers have seen certain expensive coreless ser Continued page 111 40 Model Aviation Radio Technique/Myers Continued page 33 problems evident considered signif icant time comparison objec tive obtaining additional frequencies reference individuals quali fied perform tests transmitters receivers Will procedure approved FCC b will control supervise practic es persons c What packaging shipping methods used d What requirements placed upon people e Will labels placed upon transmit ters and/or receivers standardized receiver subjected major crash receiver may off frequency yet perform control placed upon previ ously accepted equipment Will AMA allow equipment assem bled repaired owner Will AMA re quire periodic tests transmitters receivers over years reference AMA Membership Man ual p 9 AMA Frequency Committee Recom mendations para 1 AMA will assume responsibility enforcement FCC regula tions will Clubs cannot afford test equipment FCC assuredly cannot pro vide enforcement other manufactur ing level good example Citizens Band ran wild very likely questions shall arise before afier implementa tion 1991 requirements What must remembered hobby participants average mod eler limited both funds time usually complies regulations imposed equipment becomes burden enjoy ment hobby will lost 1991 frequency requirements will force RC participants pay additional fees convert existing equipment buy new equipment appears trying obtain additional frequencies fliers contest field sport fliers paying right fly Myers comment AMA sought interference free frequencies replace shared frequen cies becoming unusable sport competition fliers alike due high-powered interference sharers exclusive new channels got rid high-powered sharers would appreciate presentation questions Frequency Committee re quest reply soon possible appreciation committees ef forts Myers comment copy Mr Kennedys let ter went Fred Marks FC chairman re ply went Mr Kennedy day letter received done expense Im paid AMA service nobody re imburses time materials reproduction cosrt stamp money either Pu Isemaster/Stuecker Continued page 40 vos dont seem center well some other less-expensive standard ser vos own tests see yourself servos want use Pat tern ship Option #4 Cycle SO Microsecond Steps option checks linearity servo over its entire operating range What linearity servo truly linear will move same number degrees time pulse length incremented 50 microseconds Most servos operate over one-millisecond range servo should move 20 equal-sized steps bottom limit top limit using option See Figure #1 graph ideal servo response Option #5 Reset Upper Lower Lim its software defaults standard range pulse lengths used Ace RC others millisecond 1000 mi croseconds lower limit two mil liseconds 2000 microseconds up per limit Futaba AM series however uses 81 milliseconds 181 milliseconds system limits 1310 millisec Continued page 141 December 1988 111 Editors note RC industry has begun offer RC equipment narrow band has certified independent testing laboratories FCC type acceptance meeting AMAs Guidelines 1991 oper ation Model Aviation its AMA News sec tion now regularly publishing lists such equipment first such list appeared October 1988 issue Thus ques tions being asked renders quoted George M Myers column being swered listing RMcM NEW ELECTRIC Fly Baby. great stand-way-off scale fun ship designed 05 electric power can perform take-offs touch goes aerobatics beauty yet enjoy docile slow flight easy landings Quick easy build kit includes pre cut fuselage sides tail feathers small parts hardware complete rolled plans step-by-step instructions formed landing gear windshield Electro-Combo includes kit DSC 075 Hyperthrust motor fused switch harness Tamiya connector propeller adaptor 8/4 fiberglass propeller 4 40 Span 275 Sq area 32 oz flying weight flat bottom airfoil rudder elevator motor add ailerons too HIAVEY SPECIAL COMBO PRICE $4795 YSTEMS 675 TO WER LANE BASIC KIT $24~4ORPoRATION 215-430-8645 Pu Isemaster/Stuecker Continued page 111 onds 1310 microseconds servo center Check literature system see what range pulse widths should use its other millisecond/two millisecond standard use option reset software match system re quirements Option #6 Set Servo Position option allows generate pulse known length length set num ber microseconds enter computer keyboard prevent damage servo caused excessive travel software limits range pulse widths between 500 microseconds 2500 microseconds gives error message try exceed limits servos will hit mechan ical stops certain pulse lengths within range should type pulse length greater servo can handle servo jams quickly unplug servo re type pulse length somewhere within working range servo before re connecting Deadband check want check servos deadband type number fol lowed RETURN will cause servo assume position near cen ter its travel 1500 should servos type another number slightly larger 1505 example see servo moves doesnt move youre still within servos deadband area Keep increasing number slighfly until notice servo jisst move can usually hear motor kick dif ference between last number first number typed servos deadband microseconds good servo will have tight deadband Repeat test few times Check manufacturers specs deadband see figures agree yours yours will accurate Resolution check check servos res olution secure servo stationary ob ject small vise handy tach long pointer straight piece music wire 8 10 long servos output arm Center servo above typing 1500 place stationary reference marker next end pointer Figure #11 Move servo arm other position typing 1700 exam ple type 1500 again per fect servo pointer would return exactly original position Most will off just littlethe better servo less will off Experiment few different ser vos see really better Weve found price isnt always good indica tion good resolution deadband per formance Option #7 Measure Transmitter Pulse Length option requires have receiver compatible transmitter plan test measure transmitter pulse length plug computer de sired channel receiver after discon necting other leads receiver cluding battery computer pro vides power receiver through _________________________T SERIES planes feature balsa construction Designed intermediate flyer in A-4 mind will accept 20-25 size engine luse rear exhaust angina axceptional Skyhawk performance Tha thrill jet hassles ducted fan *4000 &H Tha Proud Bird designed meet OSPRA Formula 120 rules ThIs 1/4 scale model will accept 60120 ci size engines Epoxy glees fuselage foam wing construction Full kit $150 Semi-kit also available mo wood Sia Please add 810 581 20 Tlgershark Send check MO MasterCard VISA add $3 lea add 6% esles tax Dart ExperImental two-place full sIze aircraft Top Turkey Formulal 506$55&H PARRISH AIRCRAFT 8 Scale Models ll25SW4SthTer Plantation FL 33317 December 1988 141 SPECIALISTS IN CUSTOM COX TEE DEE & REED ENGINES 020S 049 051S & 09S ALL CUSTOM & STOCK PARTS AVAILABLE INDIVIDUALLY MANY NEW PARTS FOR OLD DISCONTINUED COX ENGINES COX PROPS & GLOW HEADS COMPETITION ACCESSORIES & CUSTOMIZED K&B ENGINES ALSO COMPLETE LINE OF RACING PARTS - GLO-BEE FIREBALL & K&B PLUGS SOLID LINES RACING WHEELS QUICK FILLS ETC WE ALSO STOCK CARBON FIBER KLOTZ OIL LATEX & SILICONE FUEL TUBING PEN BLADDER MATERIALS & HARDTO-FIND HARDWARE ESPECIALLY 2-56 & 3-48 SIZES COILS CONDENSERS NGK & STITT PLUGS SILK 12 COLORS QUALITY DOPE BRUSHES 5 & 7 LOOP RUBBER BANDS KSB SEELIG & IGNITION TIMERS GAS & DIESEL FUEL TUBING TRANSISTOR IGNITION SYSTEMS RESISTOR HI-TENSION LEADS 1/2A TEXACO PLAYBOY SR KIT 1/2A TEXACO ENGINES & PARTS EVERYTHING YOU NEED FOR OLD TIMER EVENTS servo connector Turn transmitter select op tion will notice will hor izontal scale drawn computer screen calibrated milliseconds moving pointer follows motion transmitter stick see Figure #7 prefer digital read-out pulse length theres also numeric read out measuring incoming pulse length nearest microsecond option serves two purposes can used measure end points stick travel also can used see well transmit ter sticks return neutral after theyve released Let stick snap back neutral take reading slowly return stick neutral see get same reading Move stick opposite direction same good set sticks will typi cally return within few microseconds same neutral setting time either direction measurement solved problem originally thought servo linkage problem systems plane would stay trim problem finally found sticky stick transmitter didnt al ways return same spot after re leased word cautionif select Op tion #7 have receiver connected computer have receiver connected no transmitter running computer will appear lock up nor mal Whats happening computer waiting pulse come User Port get out locked-up mode hold down Run/Stop key tap Re store keys Option #8 Slew Servo allows slowly move servo through its range using arrow keys lower right side keyboard change servo output arm position moving output arm position using option given read-out near est microsecond pulse length servo receiving option can used check servo linearity have large pointer con nected servo output arm protrac tor other means accurately determin ing pointer position could plot curve pulse length horizontal axis servo rotation vertical axis servo truly linear curve plot will turn out perfectly straight line Figure #1 have about hours work $10 can build transmitter checker automated servo testing setup using handful parts inex pensive home computer dont hap pen have Commodore C-64 computer should someone within club does computerized radio/servo checker could make interesting group project something club could make available service during meet ing rainy weekend give mem bers means checking RC systems hope find useful tool Parts List 1 ea Aileron Connector match radio sys tem 1 ea PC Card Edge Connector match Com modore C64* IC Electromcs part #41-804 #41-816 Amphenol part #225-2-12-2-4-1-01 Cinch part #251-12-30-160 1 ea Experimenters Dual IC Board Radio Shack catalog #276-159 1 ea 2N3638 MPS2907 other PNP silicon general purpose small signal transistor Radio Shack catalog #276-2023 1 ea 4700 Ohm A-watt resistor Radio Shack catalog #271-1330 1 ca 22000 Ohm A-watt resistor Radio Shack Catalog #271-1339 Solder wire miscellaneous small hand tools *The cost PC card edge connector lo cal electronics dealer approximately $375 Its also listed part number 12/245E Jameco Electronics catalog costs $149 can reach Jameco Electronics 415 592-8097 write 1355 Shoreway Rd Belmont CA 94002 Janieco has $2000 minimum order may want get few friends together prepare bulk purchase Jameco also requires 5% handling fee $100 minimum Call Ja meco cant find connector locally have handful connectors Ill pro vide $500 first-come basis until supply runs out Please include pre-addressed stamped envelope orders case check has returned software project available Commodore diskette au thor CompuServe No hard copy printout available diskette can obtained sending $500 check money order cover cost disk mailer postage Bernard L Stuecker 2433 Carey Ln Vienna VA 22180 CompuServe subscribers can GO MOD ELNET find program software dowaloading Library 11 com mand BRO KEYSERVO can get CompuServe subscription information calling CompuServe 800 848-8199 AMA member would like free CompuServe subscription kit write Doug Pratt AMA HQ 1810 Samuel Morse Dr Reston VA 22090 ModelNet AMAs computer bulletin board service need information about project please sure include pre addressed stamped envelope query address above RC Soaring/Blakeslee Continued page 43 planes DG-100/428/132/229 DG-200 Acroracer/3 75/[ 106/ 128]/293 DG-200/ 428/119/257 DG-l00/428/143/250 DG 202/500/[139/16 11/216 first DG-100 now 11 years old wings DG-200 conventional con struction 2mm balsa sheeting steel blade joiners others have blue foam cores covered fiberglass obechi made using vacuum-bag technique DG-202 50 142 Model Aviation OUR REV-UP INVENTORY AVERAGES OVER 9000 PROPS I! CALL FOR IMMEDIATE SHIPMENT ON VISA OR MASTERCARD OLD TIMER SUPPLIES ORDER BY MAIL OR PHONE 619728-4365 SORRY NO COD VISA & MASTERCARD WELCOME DEALER INQUIRES INVITED MINIMUM MERCHANDISE ORDER $1000 SHIPPING & HANDLING FEE $150 E ADD $100 auinrn IAIITLJIId 2A UfI R5
Edition: Model Aviation - 1988/12
Page Numbers: 34, 35, 36, 37, 38, 40, 111, 141, 142
Pulsemaster 64 simple circuit use Commodore C-64 computer can provide wealth information about performance servos transmitter D E 6 R E E S R 0 T T 0 N Bernard L Stuecker 40 30 20 10 0 10 20 30 40 Ideal Servo Response Figure *1 PULSES Theyre heartbeat nearly modem RC systems Theyre used tell servo what position assume Theyre sent out transmitter serial stream channel #1 first channel #2 second until theyve transmitted After last channels sent transmit ter sends out sync pulse tell re ceiver its through starts process over again typical system length pulse varies between millisecond two milliseconds depending upon posi tion stick associated chan nel Whats millisecond Its thousandth second Its 1000 microseconds Its pretty short period time typical sevenchannel transmitter can send out pulses necessary control seven servos about 22 milliseconds /45th second cluding some time electronic house keeping receiver takes stream pulses sorts out sending #1 pulse #1 servo #2 pulse #2 servo servo examines pulse receiver just sent rotates its output arm appropriate location based upon length pulse pulse example millisec ond long servo will rotate its counterclockwise position pulse two milliseconds long servo will rotate its clockwise position pulse 15 milliseconds long servo will go its center position pulse length somewhere between arm will rotate intermediate position depending incoming pulse length what mean proportional control See Figure #1 graph what ideal servo will servos same Some have much better resolution deadband others price isnt always comrnensu rate performance areas 1000 1200 1400 1600 1800 2000 PULSE LENGTH microseconds Figure 1 Servo linearity curve curve ideal servo Notice servo out put arm 45O input pulse length 1000 microseconds output arm 45O input pulse length 2000 microseconds practical world straight line could somewhat curved depending linearity servos internal electronics us interested RC electronics pulses have always source trouble Until recently its difficult accurately measure equipment available RCers 1985 Kenneth Jesser published article Ra dio Control Modeler magazine entitled Digital Pulse Meter article de scribed build inexpensive instru ment designed accurately measure length pulses Soon after article published Ace RC started selling unit called Datamaster similar Jessers origi nal Digital Pulse Meter make Datamaster versatile Ace added built-in manually controlled pulse generator AM transmitter decoder addition internal pulse generator AM transmitter decoder Datamaster came self-contained unit could used either test individual servo transmitter have Commodore C-64 com puter knowledge electronics lit tle soldering skill can build simple inexpensive circuit will perform same tests Ace Datamaster Total cost components should der $1000 computer can used replace three individual instruments digi tal pulse meter manually controlled pulse 34 Model Aviation Figure 2 section Radio Shack experimenters circuit board text has part number soldered pins connector plugged computer Note positions lands copper traces circuit board respect pins connector generator automatic servo cycler As bonus computer can measure coming pulse length accurately original digital pulse meter can mea sure pulse length nearest microsec ond can also generate high-preci sion pulses operate test automati cally cycle servo circuit associated software about describe makes use 6526 Complex Interface Adapter chip CIA inside Commodore computer generate outgoing pulses time incom ing pulses chip has hardware timers counter circuits built allow measurement time intervals between microsecond 70 seconds mi crosecond resolution timers oper ated crystal-controlled clock ac curacy stability timers out standing Fortunately us designers Commodore C-64 computer made possible access chip through User Port back computer Because output lines comput ers User Port can employed generate very accurately timed pulses can use pulses operate servo check its resolution deadband centering end points linearityfeatures interesting sport flier crucial Pattern competitor can also use computergenerated pulses under control appro priate software cause servo very slowly creep through its range check defective spots potentiometer pot motor commutator defective spots generally manifest themselves jitter output arm servo servo slowly cycled end its travel otherand usually caused either wear corrosion dirt finds its way motor pot com puter can also rapidly automatically cy cle servo end its travel other can make servo arm move specific position under con trol operator other interesting features can implemented using computers internal pulse generator lets examine other side chip al lows computer accurately measure coming pulse length About Author Bernie Stuecker has involved RC since 1979 member Northern Virginia Radio Control Club Hes past president NVRC currently edits club newsletter Feedback has circulation about 235 copies per month Bernies electronics engineer pro fession also holds amateur radio station license call sign K4XY Hes amateur radio operator nearly 25 years enjoys photography model aviation hobbyand electronics computer programming hobby well profession FIGURE *3 5 volts1 1234567891011 0~1101 ABC0EF HJKLM U A- Ground 2N3838 PNP 47KE 122K pins H Data input receiver RED BLACK Sig Out Ground *6 MALE servo plug Figure 3 Schematic diagram havent much experience working schematic may need enlist help local electronics wizard Because its possible dam age computer make wiring error take extra care make sure circuit right FIGURE *5 Receiver Battery 48 volts I I lIli Data Output Servo FEMALE servo connector RED BLACK Gig Out Ground Ii2345878 9lo1ll2jj OiKL Figure 5 Separate battery schematic plan test heavy-duty servos may wish install independent supply power power supply inside computer good up 250 MA some larger servos could exceed rating damage December 1988 35 Data Output Servo Edge Connector Back View FEMALE servo connector Figure 4 components installed circuit board per schematic should look like wires right corner will connected servo receiver Alternate Connection Independent Battery Power Ii SLBbLY CYCLE ft SERVO RAPIDLY CYCLE ft SERVO CYCLE END-CENTER-END CYCLE IN 50 1IICROSECOND STEPS RESET UPPER/LOIR UNITS SET SERVO TO POSITION ASURE TRAISKITTER PULSE NIPTN il1SLEMSERUOiJ-QtJIT Figure 6 L software options screen Heres what youll see start program make selection menu simply press appropriate number Figure 7 R select option #7 measuring transmitter pulse length computer will display moving pointer will track movements make transmitter stick Also displayed digital read-out transmitter pulse width First would want mea sure incoming pulse length some reasons Standardizing equipment Lets say have new super transmitters mixing centering adjust ments end point adjustments exponential throw dual rates above Lets say after few months tweaking controls back transmitter things get pretty far out adjustment decide move system other plane may want set controls back factory specifications just have uniform starting point use computer measure cen ter end points transmitter chan nel readjusting channel well know certain have trans mitter adjustments back normal val ues can also quickly exacfly match two transmitters used buddy-box sys tem both instructor student have equal control throw Re-establishing settings between differ ent airplanes may have two planes operate same trans mitter need different throw centering adjustments can measure channel present setup accur ately make note measure ments can go back weeks months later re-establish same conditions determined optimum plane after transmitter has used other applications Checking stability over temperature An other use would check stability transmitter over range tempera tures perform temperature test charge up transmitter place freezer refrigerator few hours until its really cold simulates flying Min nesota January pull out freezer extend antenna fully turn Make note pulse length coming out channels Let transmitFigure 9 dont plan measure transmitter pulse length wont need make buffer amplifier circuit just test servos required solder female servo con nector directly computer plug setup can use menu options except #7 36 Model Aviation Figure 8 circuit everything hooked up except computer Never remove install connector power run risk blowing out something ter continue run coming up room temperature 20 30 minutes watch pulse length warms up Dont touch transmitter sticks during period See theres much difference between cold warm pulse length chan nel under test plan fly outside winter its good idea test entire system cold weather performance especially battery Some receivers servos have known fail cold temperatures brought equipment out warm car set up took off still warm might unpleasantly surprised something stops working no apparent re ason have observed least re ceiver quits working below 32 0F Checking stability over time check transmitter over time battery dis charges perform same test above freezing transmitter first Note pulse length transmitter first activated intervals battery runs down See theres differ encethis could explain some trim changes fly other benefits standardizing transmitter servo pulse widths manufacturers specifications exam ple transmitters set up same neutral pulse length can inter change servos receivers transmitters within systems being concerned about mixing matching equipment provided connectors mate op erating positive-pulse systems build transmitter kits repair transmitters pulse length measurement system can prove invaluable About circuit youll take look Figure #3 youll notice servo lead directly connected computer no interface just happens com puter CIA chip five-volt CMOS device generates pulses directly com patible standard RC servos No interfacing required drive servo di recfly computer arent interested measuring transmitter pulses dont need build rest circuitjust hook servo connector PC card edge connector plug computer Figure #9 Youll able use options software except Op tion #7 Measure Transmitter Pulse Length Although Commodore C-64 User Port output line has worked directly servos tested far Commodore User Port input line would work re ceivers Whether computer would work depended upon chip receiver using pulse decoder make computer work cases buf fer circuit designed condition coming signal receiver cir cuit consists two resistors PNP transistor provides gain isolation between test receiver computer buffer circuit place com puter has worked positive-pulse receiver have tested date About connector PC card edge connector labeled through 12 December 1988 37 Figure 10 pencil pointing two keys used prevent connector being installed upside down Theyre made piece plastic RC hinge mate rial CyAed place Make sure use installed properly Figure 11 find out accurately servo centers itself closely returns same end point install long pointer its output arm set up fixed pointer reference Mount servo steady position align fixed pointer the servo Se lect option #3 see closely servo returns its starting point cycles end Figure 12 Radio Shack IC experimenters board inexpensive yet rugged alternate hand-wired circuit could build circuit small box connect computer cable construction method described article simpler just reliable 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order Now fliers over world have neat inexpensive functional way protect R/C transmitters dlltr dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus Georgia 31904 404/323-2787 9am-5pm EST across top through N across bottom Notice letters G missing will fit computer either right side up upside down very careful insert properlyyou could dam age computer connecting upside down Look User Port back computer Youll see has two slots cut circuit board slots de signed mate two keys PC card edge connector responsible providing keys right location connector keys place its impossible insert connector wrong way See Figure #10 proper position ing two keysthey fit small slots between contacts con nector some reason keys arent normally supplied connector theyre almost impossible find lo cal radio store worry youll find some plastic RC hinge material cut size inserted connector care fully instant-glued place will serve ade quately other cautiondont ever plug PC card edge connector computer computer turned could get crosswise during process cause problem perhaps blowing computers internal fuse doing serious damage Building circuit circuit built 1Ath Radio Shack Experimenters Dual IC Board catalog number 276-159 see Figure #12 quarter section board cut off using Dremel tool soldered bottom row contacts PC card edge connector designed match Commodore User Port see Figure #2 edge connector has dual row con tacts 12 top 12 bottom isolated other obtained local electronics store GC Electronics part number 41-804 Amphenol part num ber 225-2-12-2-4-1-01 Cinch part num ber 251-12-30-160 use connector top bottom pins internally connected together could damage Commodore computer type con nector addition connector circuit board youll need 2N3638 PNP silicon transistor other general-purpose small signal PNP transistor specs arent critical 4700 Ohm resistor 22000 Ohm resis tor aileron extension matches radio system aileron exten sion Its convenient source male female connector have some other way coming up connectors thats OK Youll also need small amount solder wire usual small hand tools circuit board soldered directly edge connector pins per photograph Figure #2 Look carefully photo graph sure have pins connector aligned proper lands Continued page 40 38 Model Aviation 015 "~ si69 k\j wraar5a prarr r 5000r~ KVrS C0rlare- ceescrAl0 r0Od 55010 rr 500 Foaer5nOeIAflg O Iras earle is 4 fl Full Size AerObIG World Now Available n Thr 5ze MOdel Kits. TANDOF gCAL t4OUNClt4G OUR HN ANeed DeS gried Miles scale 6lpLAN 5h1 3000 5pAN A rs 15t s279~sr sier~ eOd P55 $154008 d Iuth Vas LaO e giLt Certd0rCerdrgeant Orders accelltedPersO V IANSCOVER Glow Plug Analyzers metered NI-STARTER McDaniel R/C analyzes condition glow plug time use start engine attached dualface ampmeter indicates good marginal failed plug Another innovation McDaniel R/C 1650 ma/hr recharge able battery provides 35% starting power regular nicads Dual-face ampmeter indicates plug condition attached Model 205 shown Model 201 w/charger Model 218 shown Model 217 w/charger Mode 204 020 wall stainless steel tube stainless steel spring direct connecting high temp teflon wiring beryllium copper electrode No sliding contacts corrode Positive 6-point PIgIaUCk will strip wear out 1IOV 220V AC chargers available other fine products fron McDaniel R/C see local hobby dealer contact McDaniel RIC Inc 12206 Guinevere Rd Glenn Dale MD 20769 301 464-2260 FAX 301 262-4433 Visa MC accepted take hassle out hobiry NI STARTER Palen nOV2001 & osoS ow Plug k Puen Pend NI-STOOTEOsaeo Ia0emarkof McD,nelOC Inc lO8O McDaniel RIC Inc circuit board Its easy off position clarity ease testing circuit board situated non-conven tional manner copper traces top board Should wish could build circuit small box ex tend wires computer found convenient con struction technique purposes Refer schematic diagram Figure #3 photographs guidance may need obtain assistance lo cal club electronics expert havent much experience reading schemat ics constructing electronic devices ware wiring errors could permanently damage computer especially care ful check everything twice before plug ging circuit User Port Once have parts mounted cut aileron extension half solder male female connectors circuit board per Figure #4 schematic drawing Check wiring once mis take could damage computer re quire replacement CIA chip C64 Power servo receiver taken directly Conanodore power sup ply Commodore literature says port can provide five volts up 250 mil liamperes accessory devices Some large servos will exceed current rating especially stalled cases must provide battery other separate source power servo inde pendent Commodore power supply per drawing Figure #5 could damage Commodore power supply draw excess 250 milliamperes port length time Hooking up measure incoming pulse length youll need receiver match transmitter under test Power re ceiver comes Commodore com puter supply should no problem providing required power receiv ers Ive tested have required less 50 mil liamperes current Youll have remove receiver model least un plug servo connectors battery connector receiver before start Power receiver comes back through servo lead its necessary connect switch haruess battery receiver could damage Com modore power supply leave re ceiver battery connected please remove connectors receiver before start During test youll have move leads connecting computer re ceiver servo socket channel receiver other its just easy pull receiver out model avoid fumbling inside tight quarters Once connections have made thoroughly checked plug servo servo connector plug receiver con nector channel want test Turn computer load software type LOAD PULSEMASTER8 type RUN program listing software would longer article describing sys tem Ill volunteer provide disk nominal fee cover cost disk mailer postage Its also available ready-to-use form CompuServe information near end article Operating software Once have software loaded running yopll see menu will give following options Figure #6 1 Slowly cycle servo 2 Rapidly cycle servo 3 Cycle end-center-end 4 Cycle 50 microsecond steps test ing linearity 5 Reset upper lower limits accom modate various systems 6 Set servo position 7 Measure transmitter pulse length 8 Slew servo 0 Quit select option simply enter num ber desired routine Now lets talk about what options Option #1 Slowly Cycle Servo op tion would selected servo suspected being erratic may have noticed example models control surface does smoothly follow motion transmitter stick Run routine carefully watch servo signs jitter see either jitter erratic operation likely its servo potentiometer motor fault Some servos have pots can cleaned others sealed must replaced Consult manufacturer have questions simply send suspicious servos back repairits worth cost new airplane should fail Option #2 Rapidly Cycle Servo option drives servo end its travel other Its used bura new servo few minutes see problems arise exercise servo thats sitting around unused test servo consistency using elon gated pointer connected output arm Dont overdo 30 seconds min ute should sufficient test just about servo Option #3 Cycle End-Center-End option useful want test reso lution centering servo Before option employed should use Option #5 Reset Upper Lower Limits RC system uses something other millisecond lower limit two mil liseconds upper limit Option #3 causes servo go end its normal travel other pausing momen tarily middle option becomes useful long pointer temporarily attached servo arm stationary reference pointer set up midpoint servo travel see Figure #1 1 can readily observe well servo centers have seen certain expensive coreless ser Continued page 111 40 Model Aviation Radio Technique/Myers Continued page 33 problems evident considered signif icant time comparison objec tive obtaining additional frequencies reference individuals quali fied perform tests transmitters receivers Will procedure approved FCC b will control supervise practic es persons c What packaging shipping methods used d What requirements placed upon people e Will labels placed upon transmit ters and/or receivers standardized receiver subjected major crash receiver may off frequency yet perform control placed upon previ ously accepted equipment Will AMA allow equipment assem bled repaired owner Will AMA re quire periodic tests transmitters receivers over years reference AMA Membership Man ual p 9 AMA Frequency Committee Recom mendations para 1 AMA will assume responsibility enforcement FCC regula tions will Clubs cannot afford test equipment FCC assuredly cannot pro vide enforcement other manufactur ing level good example Citizens Band ran wild very likely questions shall arise before afier implementa tion 1991 requirements What must remembered hobby participants average mod eler limited both funds time usually complies regulations imposed equipment becomes burden enjoy ment hobby will lost 1991 frequency requirements will force RC participants pay additional fees convert existing equipment buy new equipment appears trying obtain additional frequencies fliers contest field sport fliers paying right fly Myers comment AMA sought interference free frequencies replace shared frequen cies becoming unusable sport competition fliers alike due high-powered interference sharers exclusive new channels got rid high-powered sharers would appreciate presentation questions Frequency Committee re quest reply soon possible appreciation committees ef forts Myers comment copy Mr Kennedys let ter went Fred Marks FC chairman re ply went Mr Kennedy day letter received done expense Im paid AMA service nobody re imburses time materials reproduction cosrt stamp money either Pu Isemaster/Stuecker Continued page 40 vos dont seem center well some other less-expensive standard ser vos own tests see yourself servos want use Pat tern ship Option #4 Cycle SO Microsecond Steps option checks linearity servo over its entire operating range What linearity servo truly linear will move same number degrees time pulse length incremented 50 microseconds Most servos operate over one-millisecond range servo should move 20 equal-sized steps bottom limit top limit using option See Figure #1 graph ideal servo response Option #5 Reset Upper Lower Lim its software defaults standard range pulse lengths used Ace RC others millisecond 1000 mi croseconds lower limit two mil liseconds 2000 microseconds up per limit Futaba AM series however uses 81 milliseconds 181 milliseconds system limits 1310 millisec Continued page 141 December 1988 111 Editors note RC industry has begun offer RC equipment narrow band has certified independent testing laboratories FCC type acceptance meeting AMAs Guidelines 1991 oper ation Model Aviation its AMA News sec tion now regularly publishing lists such equipment first such list appeared October 1988 issue Thus ques tions being asked renders quoted George M Myers column being swered listing RMcM NEW ELECTRIC Fly Baby. great stand-way-off scale fun ship designed 05 electric power can perform take-offs touch goes aerobatics beauty yet enjoy docile slow flight easy landings Quick easy build kit includes pre cut fuselage sides tail feathers small parts hardware complete rolled plans step-by-step instructions formed landing gear windshield Electro-Combo includes kit DSC 075 Hyperthrust motor fused switch harness Tamiya connector propeller adaptor 8/4 fiberglass propeller 4 40 Span 275 Sq area 32 oz flying weight flat bottom airfoil rudder elevator motor add ailerons too HIAVEY SPECIAL COMBO PRICE $4795 YSTEMS 675 TO WER LANE BASIC KIT $24~4ORPoRATION 215-430-8645 Pu Isemaster/Stuecker Continued page 111 onds 1310 microseconds servo center Check literature system see what range pulse widths should use its other millisecond/two millisecond standard use option reset software match system re quirements Option #6 Set Servo Position option allows generate pulse known length length set num ber microseconds enter computer keyboard prevent damage servo caused excessive travel software limits range pulse widths between 500 microseconds 2500 microseconds gives error message try exceed limits servos will hit mechan ical stops certain pulse lengths within range should type pulse length greater servo can handle servo jams quickly unplug servo re type pulse length somewhere within working range servo before re connecting Deadband check want check servos deadband type number fol lowed RETURN will cause servo assume position near cen ter its travel 1500 should servos type another number slightly larger 1505 example see servo moves doesnt move youre still within servos deadband area Keep increasing number slighfly until notice servo jisst move can usually hear motor kick dif ference between last number first number typed servos deadband microseconds good servo will have tight deadband Repeat test few times Check manufacturers specs deadband see figures agree yours yours will accurate Resolution check check servos res olution secure servo stationary ob ject small vise handy tach long pointer straight piece music wire 8 10 long servos output arm Center servo above typing 1500 place stationary reference marker next end pointer Figure #11 Move servo arm other position typing 1700 exam ple type 1500 again per fect servo pointer would return exactly original position Most will off just littlethe better servo less will off Experiment few different ser vos see really better Weve found price isnt always good indica tion good resolution deadband per formance Option #7 Measure Transmitter Pulse Length option requires have receiver compatible transmitter plan test measure transmitter pulse length plug computer de sired channel receiver after discon necting other leads receiver cluding battery computer pro vides power receiver through _________________________T SERIES planes feature balsa construction Designed intermediate flyer in A-4 mind will accept 20-25 size engine luse rear exhaust angina axceptional Skyhawk performance Tha thrill jet hassles ducted fan *4000 &H Tha Proud Bird designed meet OSPRA Formula 120 rules ThIs 1/4 scale model will accept 60120 ci size engines Epoxy glees fuselage foam wing construction Full kit $150 Semi-kit also available mo wood Sia Please add 810 581 20 Tlgershark Send check MO MasterCard VISA add $3 lea add 6% esles tax Dart ExperImental two-place full sIze aircraft Top Turkey Formulal 506$55&H PARRISH AIRCRAFT 8 Scale Models ll25SW4SthTer Plantation FL 33317 December 1988 141 SPECIALISTS IN CUSTOM COX TEE DEE & REED ENGINES 020S 049 051S & 09S ALL CUSTOM & STOCK PARTS AVAILABLE INDIVIDUALLY MANY NEW PARTS FOR OLD DISCONTINUED COX ENGINES COX PROPS & GLOW HEADS COMPETITION ACCESSORIES & CUSTOMIZED K&B ENGINES ALSO COMPLETE LINE OF RACING PARTS - GLO-BEE FIREBALL & K&B PLUGS SOLID LINES RACING WHEELS QUICK FILLS ETC WE ALSO STOCK CARBON FIBER KLOTZ OIL LATEX & SILICONE FUEL TUBING PEN BLADDER MATERIALS & HARDTO-FIND HARDWARE ESPECIALLY 2-56 & 3-48 SIZES COILS CONDENSERS NGK & STITT PLUGS SILK 12 COLORS QUALITY DOPE BRUSHES 5 & 7 LOOP RUBBER BANDS KSB SEELIG & IGNITION TIMERS GAS & DIESEL FUEL TUBING TRANSISTOR IGNITION SYSTEMS RESISTOR HI-TENSION LEADS 1/2A TEXACO PLAYBOY SR KIT 1/2A TEXACO ENGINES & PARTS EVERYTHING YOU NEED FOR OLD TIMER EVENTS servo connector Turn transmitter select op tion will notice will hor izontal scale drawn computer screen calibrated milliseconds moving pointer follows motion transmitter stick see Figure #7 prefer digital read-out pulse length theres also numeric read out measuring incoming pulse length nearest microsecond option serves two purposes can used measure end points stick travel also can used see well transmit ter sticks return neutral after theyve released Let stick snap back neutral take reading slowly return stick neutral see get same reading Move stick opposite direction same good set sticks will typi cally return within few microseconds same neutral setting time either direction measurement solved problem originally thought servo linkage problem systems plane would stay trim problem finally found sticky stick transmitter didnt al ways return same spot after re leased word cautionif select Op tion #7 have receiver connected computer have receiver connected no transmitter running computer will appear lock up nor mal Whats happening computer waiting pulse come User Port get out locked-up mode hold down Run/Stop key tap Re store keys Option #8 Slew Servo allows slowly move servo through its range using arrow keys lower right side keyboard change servo output arm position moving output arm position using option given read-out near est microsecond pulse length servo receiving option can used check servo linearity have large pointer con nected servo output arm protrac tor other means accurately determin ing pointer position could plot curve pulse length horizontal axis servo rotation vertical axis servo truly linear curve plot will turn out perfectly straight line Figure #1 have about hours work $10 can build transmitter checker automated servo testing setup using handful parts inex pensive home computer dont hap pen have Commodore C-64 computer should someone within club does computerized radio/servo checker could make interesting group project something club could make available service during meet ing rainy weekend give mem bers means checking RC systems hope find useful tool Parts List 1 ea Aileron Connector match radio sys tem 1 ea PC Card Edge Connector match Com modore C64* IC Electromcs part #41-804 #41-816 Amphenol part #225-2-12-2-4-1-01 Cinch part #251-12-30-160 1 ea Experimenters Dual IC Board Radio Shack catalog #276-159 1 ea 2N3638 MPS2907 other PNP silicon general purpose small signal transistor Radio Shack catalog #276-2023 1 ea 4700 Ohm A-watt resistor Radio Shack catalog #271-1330 1 ca 22000 Ohm A-watt resistor Radio Shack Catalog #271-1339 Solder wire miscellaneous small hand tools *The cost PC card edge connector lo cal electronics dealer approximately $375 Its also listed part number 12/245E Jameco Electronics catalog costs $149 can reach Jameco Electronics 415 592-8097 write 1355 Shoreway Rd Belmont CA 94002 Janieco has $2000 minimum order may want get few friends together prepare bulk purchase Jameco also requires 5% handling fee $100 minimum Call Ja meco cant find connector locally have handful connectors Ill pro vide $500 first-come basis until supply runs out Please include pre-addressed stamped envelope orders case check has returned software project available Commodore diskette au thor CompuServe No hard copy printout available diskette can obtained sending $500 check money order cover cost disk mailer postage Bernard L Stuecker 2433 Carey Ln Vienna VA 22180 CompuServe subscribers can GO MOD ELNET find program software dowaloading Library 11 com mand BRO KEYSERVO can get CompuServe subscription information calling CompuServe 800 848-8199 AMA member would like free CompuServe subscription kit write Doug Pratt AMA HQ 1810 Samuel Morse Dr Reston VA 22090 ModelNet AMAs computer bulletin board service need information about project please sure include pre addressed stamped envelope query address above RC Soaring/Blakeslee Continued page 43 planes DG-100/428/132/229 DG-200 Acroracer/3 75/[ 106/ 128]/293 DG-200/ 428/119/257 DG-l00/428/143/250 DG 202/500/[139/16 11/216 first DG-100 now 11 years old wings DG-200 conventional con struction 2mm balsa sheeting steel blade joiners others have blue foam cores covered fiberglass obechi made using vacuum-bag technique DG-202 50 142 Model Aviation OUR REV-UP INVENTORY AVERAGES OVER 9000 PROPS I! CALL FOR IMMEDIATE SHIPMENT ON VISA OR MASTERCARD OLD TIMER SUPPLIES ORDER BY MAIL OR PHONE 619728-4365 SORRY NO COD VISA & MASTERCARD WELCOME DEALER INQUIRES INVITED MINIMUM MERCHANDISE ORDER $1000 SHIPPING & HANDLING FEE $150 E ADD $100 auinrn IAIITLJIId 2A UfI R5
Edition: Model Aviation - 1988/12
Page Numbers: 34, 35, 36, 37, 38, 40, 111, 141, 142
Pulsemaster 64 simple circuit use Commodore C-64 computer can provide wealth information about performance servos transmitter D E 6 R E E S R 0 T T 0 N Bernard L Stuecker 40 30 20 10 0 10 20 30 40 Ideal Servo Response Figure *1 PULSES Theyre heartbeat nearly modem RC systems Theyre used tell servo what position assume Theyre sent out transmitter serial stream channel #1 first channel #2 second until theyve transmitted After last channels sent transmit ter sends out sync pulse tell re ceiver its through starts process over again typical system length pulse varies between millisecond two milliseconds depending upon posi tion stick associated chan nel Whats millisecond Its thousandth second Its 1000 microseconds Its pretty short period time typical sevenchannel transmitter can send out pulses necessary control seven servos about 22 milliseconds /45th second cluding some time electronic house keeping receiver takes stream pulses sorts out sending #1 pulse #1 servo #2 pulse #2 servo servo examines pulse receiver just sent rotates its output arm appropriate location based upon length pulse pulse example millisec ond long servo will rotate its counterclockwise position pulse two milliseconds long servo will rotate its clockwise position pulse 15 milliseconds long servo will go its center position pulse length somewhere between arm will rotate intermediate position depending incoming pulse length what mean proportional control See Figure #1 graph what ideal servo will servos same Some have much better resolution deadband others price isnt always comrnensu rate performance areas 1000 1200 1400 1600 1800 2000 PULSE LENGTH microseconds Figure 1 Servo linearity curve curve ideal servo Notice servo out put arm 45O input pulse length 1000 microseconds output arm 45O input pulse length 2000 microseconds practical world straight line could somewhat curved depending linearity servos internal electronics us interested RC electronics pulses have always source trouble Until recently its difficult accurately measure equipment available RCers 1985 Kenneth Jesser published article Ra dio Control Modeler magazine entitled Digital Pulse Meter article de scribed build inexpensive instru ment designed accurately measure length pulses Soon after article published Ace RC started selling unit called Datamaster similar Jessers origi nal Digital Pulse Meter make Datamaster versatile Ace added built-in manually controlled pulse generator AM transmitter decoder addition internal pulse generator AM transmitter decoder Datamaster came self-contained unit could used either test individual servo transmitter have Commodore C-64 com puter knowledge electronics lit tle soldering skill can build simple inexpensive circuit will perform same tests Ace Datamaster Total cost components should der $1000 computer can used replace three individual instruments digi tal pulse meter manually controlled pulse 34 Model Aviation Figure 2 section Radio Shack experimenters circuit board text has part number soldered pins connector plugged computer Note positions lands copper traces circuit board respect pins connector generator automatic servo cycler As bonus computer can measure coming pulse length accurately original digital pulse meter can mea sure pulse length nearest microsec ond can also generate high-preci sion pulses operate test automati cally cycle servo circuit associated software about describe makes use 6526 Complex Interface Adapter chip CIA inside Commodore computer generate outgoing pulses time incom ing pulses chip has hardware timers counter circuits built allow measurement time intervals between microsecond 70 seconds mi crosecond resolution timers oper ated crystal-controlled clock ac curacy stability timers out standing Fortunately us designers Commodore C-64 computer made possible access chip through User Port back computer Because output lines comput ers User Port can employed generate very accurately timed pulses can use pulses operate servo check its resolution deadband centering end points linearityfeatures interesting sport flier crucial Pattern competitor can also use computergenerated pulses under control appro priate software cause servo very slowly creep through its range check defective spots potentiometer pot motor commutator defective spots generally manifest themselves jitter output arm servo servo slowly cycled end its travel otherand usually caused either wear corrosion dirt finds its way motor pot com puter can also rapidly automatically cy cle servo end its travel other can make servo arm move specific position under con trol operator other interesting features can implemented using computers internal pulse generator lets examine other side chip al lows computer accurately measure coming pulse length About Author Bernie Stuecker has involved RC since 1979 member Northern Virginia Radio Control Club Hes past president NVRC currently edits club newsletter Feedback has circulation about 235 copies per month Bernies electronics engineer pro fession also holds amateur radio station license call sign K4XY Hes amateur radio operator nearly 25 years enjoys photography model aviation hobbyand electronics computer programming hobby well profession FIGURE *3 5 volts1 1234567891011 0~1101 ABC0EF HJKLM U A- Ground 2N3838 PNP 47KE 122K pins H Data input receiver RED BLACK Sig Out Ground *6 MALE servo plug Figure 3 Schematic diagram havent much experience working schematic may need enlist help local electronics wizard Because its possible dam age computer make wiring error take extra care make sure circuit right FIGURE *5 Receiver Battery 48 volts I I lIli Data Output Servo FEMALE servo connector RED BLACK Gig Out Ground Ii2345878 9lo1ll2jj OiKL Figure 5 Separate battery schematic plan test heavy-duty servos may wish install independent supply power power supply inside computer good up 250 MA some larger servos could exceed rating damage December 1988 35 Data Output Servo Edge Connector Back View FEMALE servo connector Figure 4 components installed circuit board per schematic should look like wires right corner will connected servo receiver Alternate Connection Independent Battery Power Ii SLBbLY CYCLE ft SERVO RAPIDLY CYCLE ft SERVO CYCLE END-CENTER-END CYCLE IN 50 1IICROSECOND STEPS RESET UPPER/LOIR UNITS SET SERVO TO POSITION ASURE TRAISKITTER PULSE NIPTN il1SLEMSERUOiJ-QtJIT Figure 6 L software options screen Heres what youll see start program make selection menu simply press appropriate number Figure 7 R select option #7 measuring transmitter pulse length computer will display moving pointer will track movements make transmitter stick Also displayed digital read-out transmitter pulse width First would want mea sure incoming pulse length some reasons Standardizing equipment Lets say have new super transmitters mixing centering adjust ments end point adjustments exponential throw dual rates above Lets say after few months tweaking controls back transmitter things get pretty far out adjustment decide move system other plane may want set controls back factory specifications just have uniform starting point use computer measure cen ter end points transmitter chan nel readjusting channel well know certain have trans mitter adjustments back normal val ues can also quickly exacfly match two transmitters used buddy-box sys tem both instructor student have equal control throw Re-establishing settings between differ ent airplanes may have two planes operate same trans mitter need different throw centering adjustments can measure channel present setup accur ately make note measure ments can go back weeks months later re-establish same conditions determined optimum plane after transmitter has used other applications Checking stability over temperature An other use would check stability transmitter over range tempera tures perform temperature test charge up transmitter place freezer refrigerator few hours until its really cold simulates flying Min nesota January pull out freezer extend antenna fully turn Make note pulse length coming out channels Let transmitFigure 9 dont plan measure transmitter pulse length wont need make buffer amplifier circuit just test servos required solder female servo con nector directly computer plug setup can use menu options except #7 36 Model Aviation Figure 8 circuit everything hooked up except computer Never remove install connector power run risk blowing out something ter continue run coming up room temperature 20 30 minutes watch pulse length warms up Dont touch transmitter sticks during period See theres much difference between cold warm pulse length chan nel under test plan fly outside winter its good idea test entire system cold weather performance especially battery Some receivers servos have known fail cold temperatures brought equipment out warm car set up took off still warm might unpleasantly surprised something stops working no apparent re ason have observed least re ceiver quits working below 32 0F Checking stability over time check transmitter over time battery dis charges perform same test above freezing transmitter first Note pulse length transmitter first activated intervals battery runs down See theres differ encethis could explain some trim changes fly other benefits standardizing transmitter servo pulse widths manufacturers specifications exam ple transmitters set up same neutral pulse length can inter change servos receivers transmitters within systems being concerned about mixing matching equipment provided connectors mate op erating positive-pulse systems build transmitter kits repair transmitters pulse length measurement system can prove invaluable About circuit youll take look Figure #3 youll notice servo lead directly connected computer no interface just happens com puter CIA chip five-volt CMOS device generates pulses directly com patible standard RC servos No interfacing required drive servo di recfly computer arent interested measuring transmitter pulses dont need build rest circuitjust hook servo connector PC card edge connector plug computer Figure #9 Youll able use options software except Op tion #7 Measure Transmitter Pulse Length Although Commodore C-64 User Port output line has worked directly servos tested far Commodore User Port input line would work re ceivers Whether computer would work depended upon chip receiver using pulse decoder make computer work cases buf fer circuit designed condition coming signal receiver cir cuit consists two resistors PNP transistor provides gain isolation between test receiver computer buffer circuit place com puter has worked positive-pulse receiver have tested date About connector PC card edge connector labeled through 12 December 1988 37 Figure 10 pencil pointing two keys used prevent connector being installed upside down Theyre made piece plastic RC hinge mate rial CyAed place Make sure use installed properly Figure 11 find out accurately servo centers itself closely returns same end point install long pointer its output arm set up fixed pointer reference Mount servo steady position align fixed pointer the servo Se lect option #3 see closely servo returns its starting point cycles end Figure 12 Radio Shack IC experimenters board inexpensive yet rugged alternate hand-wired circuit could build circuit small box connect computer cable construction method described article simpler just reliable 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order Now fliers over world have neat inexpensive functional way protect R/C transmitters dlltr dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus Georgia 31904 404/323-2787 9am-5pm EST across top through N across bottom Notice letters G missing will fit computer either right side up upside down very careful insert properlyyou could dam age computer connecting upside down Look User Port back computer Youll see has two slots cut circuit board slots de signed mate two keys PC card edge connector responsible providing keys right location connector keys place its impossible insert connector wrong way See Figure #10 proper position ing two keysthey fit small slots between contacts con nector some reason keys arent normally supplied connector theyre almost impossible find lo cal radio store worry youll find some plastic RC hinge material cut size inserted connector care fully instant-glued place will serve ade quately other cautiondont ever plug PC card edge connector computer computer turned could get crosswise during process cause problem perhaps blowing computers internal fuse doing serious damage Building circuit circuit built 1Ath Radio Shack Experimenters Dual IC Board catalog number 276-159 see Figure #12 quarter section board cut off using Dremel tool soldered bottom row contacts PC card edge connector designed match Commodore User Port see Figure #2 edge connector has dual row con tacts 12 top 12 bottom isolated other obtained local electronics store GC Electronics part number 41-804 Amphenol part num ber 225-2-12-2-4-1-01 Cinch part num ber 251-12-30-160 use connector top bottom pins internally connected together could damage Commodore computer type con nector addition connector circuit board youll need 2N3638 PNP silicon transistor other general-purpose small signal PNP transistor specs arent critical 4700 Ohm resistor 22000 Ohm resis tor aileron extension matches radio system aileron exten sion Its convenient source male female connector have some other way coming up connectors thats OK Youll also need small amount solder wire usual small hand tools circuit board soldered directly edge connector pins per photograph Figure #2 Look carefully photo graph sure have pins connector aligned proper lands Continued page 40 38 Model Aviation 015 "~ si69 k\j wraar5a prarr r 5000r~ KVrS C0rlare- ceescrAl0 r0Od 55010 rr 500 Foaer5nOeIAflg O Iras earle is 4 fl Full Size AerObIG World Now Available n Thr 5ze MOdel Kits. TANDOF gCAL t4OUNClt4G OUR HN ANeed DeS gried Miles scale 6lpLAN 5h1 3000 5pAN A rs 15t s279~sr sier~ eOd P55 $154008 d Iuth Vas LaO e giLt Certd0rCerdrgeant Orders accelltedPersO V IANSCOVER Glow Plug Analyzers metered NI-STARTER McDaniel R/C analyzes condition glow plug time use start engine attached dualface ampmeter indicates good marginal failed plug Another innovation McDaniel R/C 1650 ma/hr recharge able battery provides 35% starting power regular nicads Dual-face ampmeter indicates plug condition attached Model 205 shown Model 201 w/charger Model 218 shown Model 217 w/charger Mode 204 020 wall stainless steel tube stainless steel spring direct connecting high temp teflon wiring beryllium copper electrode No sliding contacts corrode Positive 6-point PIgIaUCk will strip wear out 1IOV 220V AC chargers available other fine products fron McDaniel R/C see local hobby dealer contact McDaniel RIC Inc 12206 Guinevere Rd Glenn Dale MD 20769 301 464-2260 FAX 301 262-4433 Visa MC accepted take hassle out hobiry NI STARTER Palen nOV2001 & osoS ow Plug k Puen Pend NI-STOOTEOsaeo Ia0emarkof McD,nelOC Inc lO8O McDaniel RIC Inc circuit board Its easy off position clarity ease testing circuit board situated non-conven tional manner copper traces top board Should wish could build circuit small box ex tend wires computer found convenient con struction technique purposes Refer schematic diagram Figure #3 photographs guidance may need obtain assistance lo cal club electronics expert havent much experience reading schemat ics constructing electronic devices ware wiring errors could permanently damage computer especially care ful check everything twice before plug ging circuit User Port Once have parts mounted cut aileron extension half solder male female connectors circuit board per Figure #4 schematic drawing Check wiring once mis take could damage computer re quire replacement CIA chip C64 Power servo receiver taken directly Conanodore power sup ply Commodore literature says port can provide five volts up 250 mil liamperes accessory devices Some large servos will exceed current rating especially stalled cases must provide battery other separate source power servo inde pendent Commodore power supply per drawing Figure #5 could damage Commodore power supply draw excess 250 milliamperes port length time Hooking up measure incoming pulse length youll need receiver match transmitter under test Power re ceiver comes Commodore com puter supply should no problem providing required power receiv ers Ive tested have required less 50 mil liamperes current Youll have remove receiver model least un plug servo connectors battery connector receiver before start Power receiver comes back through servo lead its necessary connect switch haruess battery receiver could damage Com modore power supply leave re ceiver battery connected please remove connectors receiver before start During test youll have move leads connecting computer re ceiver servo socket channel receiver other its just easy pull receiver out model avoid fumbling inside tight quarters Once connections have made thoroughly checked plug servo servo connector plug receiver con nector channel want test Turn computer load software type LOAD PULSEMASTER8 type RUN program listing software would longer article describing sys tem Ill volunteer provide disk nominal fee cover cost disk mailer postage Its also available ready-to-use form CompuServe information near end article Operating software Once have software loaded running yopll see menu will give following options Figure #6 1 Slowly cycle servo 2 Rapidly cycle servo 3 Cycle end-center-end 4 Cycle 50 microsecond steps test ing linearity 5 Reset upper lower limits accom modate various systems 6 Set servo position 7 Measure transmitter pulse length 8 Slew servo 0 Quit select option simply enter num ber desired routine Now lets talk about what options Option #1 Slowly Cycle Servo op tion would selected servo suspected being erratic may have noticed example models control surface does smoothly follow motion transmitter stick Run routine carefully watch servo signs jitter see either jitter erratic operation likely its servo potentiometer motor fault Some servos have pots can cleaned others sealed must replaced Consult manufacturer have questions simply send suspicious servos back repairits worth cost new airplane should fail Option #2 Rapidly Cycle Servo option drives servo end its travel other Its used bura new servo few minutes see problems arise exercise servo thats sitting around unused test servo consistency using elon gated pointer connected output arm Dont overdo 30 seconds min ute should sufficient test just about servo Option #3 Cycle End-Center-End option useful want test reso lution centering servo Before option employed should use Option #5 Reset Upper Lower Limits RC system uses something other millisecond lower limit two mil liseconds upper limit Option #3 causes servo go end its normal travel other pausing momen tarily middle option becomes useful long pointer temporarily attached servo arm stationary reference pointer set up midpoint servo travel see Figure #1 1 can readily observe well servo centers have seen certain expensive coreless ser Continued page 111 40 Model Aviation Radio Technique/Myers Continued page 33 problems evident considered signif icant time comparison objec tive obtaining additional frequencies reference individuals quali fied perform tests transmitters receivers Will procedure approved FCC b will control supervise practic es persons c What packaging shipping methods used d What requirements placed upon people e Will labels placed upon transmit ters and/or receivers standardized receiver subjected major crash receiver may off frequency yet perform control placed upon previ ously accepted equipment Will AMA allow equipment assem bled repaired owner Will AMA re quire periodic tests transmitters receivers over years reference AMA Membership Man ual p 9 AMA Frequency Committee Recom mendations para 1 AMA will assume responsibility enforcement FCC regula tions will Clubs cannot afford test equipment FCC assuredly cannot pro vide enforcement other manufactur ing level good example Citizens Band ran wild very likely questions shall arise before afier implementa tion 1991 requirements What must remembered hobby participants average mod eler limited both funds time usually complies regulations imposed equipment becomes burden enjoy ment hobby will lost 1991 frequency requirements will force RC participants pay additional fees convert existing equipment buy new equipment appears trying obtain additional frequencies fliers contest field sport fliers paying right fly Myers comment AMA sought interference free frequencies replace shared frequen cies becoming unusable sport competition fliers alike due high-powered interference sharers exclusive new channels got rid high-powered sharers would appreciate presentation questions Frequency Committee re quest reply soon possible appreciation committees ef forts Myers comment copy Mr Kennedys let ter went Fred Marks FC chairman re ply went Mr Kennedy day letter received done expense Im paid AMA service nobody re imburses time materials reproduction cosrt stamp money either Pu Isemaster/Stuecker Continued page 40 vos dont seem center well some other less-expensive standard ser vos own tests see yourself servos want use Pat tern ship Option #4 Cycle SO Microsecond Steps option checks linearity servo over its entire operating range What linearity servo truly linear will move same number degrees time pulse length incremented 50 microseconds Most servos operate over one-millisecond range servo should move 20 equal-sized steps bottom limit top limit using option See Figure #1 graph ideal servo response Option #5 Reset Upper Lower Lim its software defaults standard range pulse lengths used Ace RC others millisecond 1000 mi croseconds lower limit two mil liseconds 2000 microseconds up per limit Futaba AM series however uses 81 milliseconds 181 milliseconds system limits 1310 millisec Continued page 141 December 1988 111 Editors note RC industry has begun offer RC equipment narrow band has certified independent testing laboratories FCC type acceptance meeting AMAs Guidelines 1991 oper ation Model Aviation its AMA News sec tion now regularly publishing lists such equipment first such list appeared October 1988 issue Thus ques tions being asked renders quoted George M Myers column being swered listing RMcM NEW ELECTRIC Fly Baby. great stand-way-off scale fun ship designed 05 electric power can perform take-offs touch goes aerobatics beauty yet enjoy docile slow flight easy landings Quick easy build kit includes pre cut fuselage sides tail feathers small parts hardware complete rolled plans step-by-step instructions formed landing gear windshield Electro-Combo includes kit DSC 075 Hyperthrust motor fused switch harness Tamiya connector propeller adaptor 8/4 fiberglass propeller 4 40 Span 275 Sq area 32 oz flying weight flat bottom airfoil rudder elevator motor add ailerons too HIAVEY SPECIAL COMBO PRICE $4795 YSTEMS 675 TO WER LANE BASIC KIT $24~4ORPoRATION 215-430-8645 Pu Isemaster/Stuecker Continued page 111 onds 1310 microseconds servo center Check literature system see what range pulse widths should use its other millisecond/two millisecond standard use option reset software match system re quirements Option #6 Set Servo Position option allows generate pulse known length length set num ber microseconds enter computer keyboard prevent damage servo caused excessive travel software limits range pulse widths between 500 microseconds 2500 microseconds gives error message try exceed limits servos will hit mechan ical stops certain pulse lengths within range should type pulse length greater servo can handle servo jams quickly unplug servo re type pulse length somewhere within working range servo before re connecting Deadband check want check servos deadband type number fol lowed RETURN will cause servo assume position near cen ter its travel 1500 should servos type another number slightly larger 1505 example see servo moves doesnt move youre still within servos deadband area Keep increasing number slighfly until notice servo jisst move can usually hear motor kick dif ference between last number first number typed servos deadband microseconds good servo will have tight deadband Repeat test few times Check manufacturers specs deadband see figures agree yours yours will accurate Resolution check check servos res olution secure servo stationary ob ject small vise handy tach long pointer straight piece music wire 8 10 long servos output arm Center servo above typing 1500 place stationary reference marker next end pointer Figure #11 Move servo arm other position typing 1700 exam ple type 1500 again per fect servo pointer would return exactly original position Most will off just littlethe better servo less will off Experiment few different ser vos see really better Weve found price isnt always good indica tion good resolution deadband per formance Option #7 Measure Transmitter Pulse Length option requires have receiver compatible transmitter plan test measure transmitter pulse length plug computer de sired channel receiver after discon necting other leads receiver cluding battery computer pro vides power receiver through _________________________T SERIES planes feature balsa construction Designed intermediate flyer in A-4 mind will accept 20-25 size engine luse rear exhaust angina axceptional Skyhawk performance Tha thrill jet hassles ducted fan *4000 &H Tha Proud Bird designed meet OSPRA Formula 120 rules ThIs 1/4 scale model will accept 60120 ci size engines Epoxy glees fuselage foam wing construction Full kit $150 Semi-kit also available mo wood Sia Please add 810 581 20 Tlgershark Send check MO MasterCard VISA add $3 lea add 6% esles tax Dart ExperImental two-place full sIze aircraft Top Turkey Formulal 506$55&H PARRISH AIRCRAFT 8 Scale Models ll25SW4SthTer Plantation FL 33317 December 1988 141 SPECIALISTS IN CUSTOM COX TEE DEE & REED ENGINES 020S 049 051S & 09S ALL CUSTOM & STOCK PARTS AVAILABLE INDIVIDUALLY MANY NEW PARTS FOR OLD DISCONTINUED COX ENGINES COX PROPS & GLOW HEADS COMPETITION ACCESSORIES & CUSTOMIZED K&B ENGINES ALSO COMPLETE LINE OF RACING PARTS - GLO-BEE FIREBALL & K&B PLUGS SOLID LINES RACING WHEELS QUICK FILLS ETC WE ALSO STOCK CARBON FIBER KLOTZ OIL LATEX & SILICONE FUEL TUBING PEN BLADDER MATERIALS & HARDTO-FIND HARDWARE ESPECIALLY 2-56 & 3-48 SIZES COILS CONDENSERS NGK & STITT PLUGS SILK 12 COLORS QUALITY DOPE BRUSHES 5 & 7 LOOP RUBBER BANDS KSB SEELIG & IGNITION TIMERS GAS & DIESEL FUEL TUBING TRANSISTOR IGNITION SYSTEMS RESISTOR HI-TENSION LEADS 1/2A TEXACO PLAYBOY SR KIT 1/2A TEXACO ENGINES & PARTS EVERYTHING YOU NEED FOR OLD TIMER EVENTS servo connector Turn transmitter select op tion will notice will hor izontal scale drawn computer screen calibrated milliseconds moving pointer follows motion transmitter stick see Figure #7 prefer digital read-out pulse length theres also numeric read out measuring incoming pulse length nearest microsecond option serves two purposes can used measure end points stick travel also can used see well transmit ter sticks return neutral after theyve released Let stick snap back neutral take reading slowly return stick neutral see get same reading Move stick opposite direction same good set sticks will typi cally return within few microseconds same neutral setting time either direction measurement solved problem originally thought servo linkage problem systems plane would stay trim problem finally found sticky stick transmitter didnt al ways return same spot after re leased word cautionif select Op tion #7 have receiver connected computer have receiver connected no transmitter running computer will appear lock up nor mal Whats happening computer waiting pulse come User Port get out locked-up mode hold down Run/Stop key tap Re store keys Option #8 Slew Servo allows slowly move servo through its range using arrow keys lower right side keyboard change servo output arm position moving output arm position using option given read-out near est microsecond pulse length servo receiving option can used check servo linearity have large pointer con nected servo output arm protrac tor other means accurately determin ing pointer position could plot curve pulse length horizontal axis servo rotation vertical axis servo truly linear curve plot will turn out perfectly straight line Figure #1 have about hours work $10 can build transmitter checker automated servo testing setup using handful parts inex pensive home computer dont hap pen have Commodore C-64 computer should someone within club does computerized radio/servo checker could make interesting group project something club could make available service during meet ing rainy weekend give mem bers means checking RC systems hope find useful tool Parts List 1 ea Aileron Connector match radio sys tem 1 ea PC Card Edge Connector match Com modore C64* IC Electromcs part #41-804 #41-816 Amphenol part #225-2-12-2-4-1-01 Cinch part #251-12-30-160 1 ea Experimenters Dual IC Board Radio Shack catalog #276-159 1 ea 2N3638 MPS2907 other PNP silicon general purpose small signal transistor Radio Shack catalog #276-2023 1 ea 4700 Ohm A-watt resistor Radio Shack catalog #271-1330 1 ca 22000 Ohm A-watt resistor Radio Shack Catalog #271-1339 Solder wire miscellaneous small hand tools *The cost PC card edge connector lo cal electronics dealer approximately $375 Its also listed part number 12/245E Jameco Electronics catalog costs $149 can reach Jameco Electronics 415 592-8097 write 1355 Shoreway Rd Belmont CA 94002 Janieco has $2000 minimum order may want get few friends together prepare bulk purchase Jameco also requires 5% handling fee $100 minimum Call Ja meco cant find connector locally have handful connectors Ill pro vide $500 first-come basis until supply runs out Please include pre-addressed stamped envelope orders case check has returned software project available Commodore diskette au thor CompuServe No hard copy printout available diskette can obtained sending $500 check money order cover cost disk mailer postage Bernard L Stuecker 2433 Carey Ln Vienna VA 22180 CompuServe subscribers can GO MOD ELNET find program software dowaloading Library 11 com mand BRO KEYSERVO can get CompuServe subscription information calling CompuServe 800 848-8199 AMA member would like free CompuServe subscription kit write Doug Pratt AMA HQ 1810 Samuel Morse Dr Reston VA 22090 ModelNet AMAs computer bulletin board service need information about project please sure include pre addressed stamped envelope query address above RC Soaring/Blakeslee Continued page 43 planes DG-100/428/132/229 DG-200 Acroracer/3 75/[ 106/ 128]/293 DG-200/ 428/119/257 DG-l00/428/143/250 DG 202/500/[139/16 11/216 first DG-100 now 11 years old wings DG-200 conventional con struction 2mm balsa sheeting steel blade joiners others have blue foam cores covered fiberglass obechi made using vacuum-bag technique DG-202 50 142 Model Aviation OUR REV-UP INVENTORY AVERAGES OVER 9000 PROPS I! CALL FOR IMMEDIATE SHIPMENT ON VISA OR MASTERCARD OLD TIMER SUPPLIES ORDER BY MAIL OR PHONE 619728-4365 SORRY NO COD VISA & MASTERCARD WELCOME DEALER INQUIRES INVITED MINIMUM MERCHANDISE ORDER $1000 SHIPPING & HANDLING FEE $150 E ADD $100 auinrn IAIITLJIId 2A UfI R5
Edition: Model Aviation - 1988/12
Page Numbers: 34, 35, 36, 37, 38, 40, 111, 141, 142
Pulsemaster 64 simple circuit use Commodore C-64 computer can provide wealth information about performance servos transmitter D E 6 R E E S R 0 T T 0 N Bernard L Stuecker 40 30 20 10 0 10 20 30 40 Ideal Servo Response Figure *1 PULSES Theyre heartbeat nearly modem RC systems Theyre used tell servo what position assume Theyre sent out transmitter serial stream channel #1 first channel #2 second until theyve transmitted After last channels sent transmit ter sends out sync pulse tell re ceiver its through starts process over again typical system length pulse varies between millisecond two milliseconds depending upon posi tion stick associated chan nel Whats millisecond Its thousandth second Its 1000 microseconds Its pretty short period time typical sevenchannel transmitter can send out pulses necessary control seven servos about 22 milliseconds /45th second cluding some time electronic house keeping receiver takes stream pulses sorts out sending #1 pulse #1 servo #2 pulse #2 servo servo examines pulse receiver just sent rotates its output arm appropriate location based upon length pulse pulse example millisec ond long servo will rotate its counterclockwise position pulse two milliseconds long servo will rotate its clockwise position pulse 15 milliseconds long servo will go its center position pulse length somewhere between arm will rotate intermediate position depending incoming pulse length what mean proportional control See Figure #1 graph what ideal servo will servos same Some have much better resolution deadband others price isnt always comrnensu rate performance areas 1000 1200 1400 1600 1800 2000 PULSE LENGTH microseconds Figure 1 Servo linearity curve curve ideal servo Notice servo out put arm 45O input pulse length 1000 microseconds output arm 45O input pulse length 2000 microseconds practical world straight line could somewhat curved depending linearity servos internal electronics us interested RC electronics pulses have always source trouble Until recently its difficult accurately measure equipment available RCers 1985 Kenneth Jesser published article Ra dio Control Modeler magazine entitled Digital Pulse Meter article de scribed build inexpensive instru ment designed accurately measure length pulses Soon after article published Ace RC started selling unit called Datamaster similar Jessers origi nal Digital Pulse Meter make Datamaster versatile Ace added built-in manually controlled pulse generator AM transmitter decoder addition internal pulse generator AM transmitter decoder Datamaster came self-contained unit could used either test individual servo transmitter have Commodore C-64 com puter knowledge electronics lit tle soldering skill can build simple inexpensive circuit will perform same tests Ace Datamaster Total cost components should der $1000 computer can used replace three individual instruments digi tal pulse meter manually controlled pulse 34 Model Aviation Figure 2 section Radio Shack experimenters circuit board text has part number soldered pins connector plugged computer Note positions lands copper traces circuit board respect pins connector generator automatic servo cycler As bonus computer can measure coming pulse length accurately original digital pulse meter can mea sure pulse length nearest microsec ond can also generate high-preci sion pulses operate test automati cally cycle servo circuit associated software about describe makes use 6526 Complex Interface Adapter chip CIA inside Commodore computer generate outgoing pulses time incom ing pulses chip has hardware timers counter circuits built allow measurement time intervals between microsecond 70 seconds mi crosecond resolution timers oper ated crystal-controlled clock ac curacy stability timers out standing Fortunately us designers Commodore C-64 computer made possible access chip through User Port back computer Because output lines comput ers User Port can employed generate very accurately timed pulses can use pulses operate servo check its resolution deadband centering end points linearityfeatures interesting sport flier crucial Pattern competitor can also use computergenerated pulses under control appro priate software cause servo very slowly creep through its range check defective spots potentiometer pot motor commutator defective spots generally manifest themselves jitter output arm servo servo slowly cycled end its travel otherand usually caused either wear corrosion dirt finds its way motor pot com puter can also rapidly automatically cy cle servo end its travel other can make servo arm move specific position under con trol operator other interesting features can implemented using computers internal pulse generator lets examine other side chip al lows computer accurately measure coming pulse length About Author Bernie Stuecker has involved RC since 1979 member Northern Virginia Radio Control Club Hes past president NVRC currently edits club newsletter Feedback has circulation about 235 copies per month Bernies electronics engineer pro fession also holds amateur radio station license call sign K4XY Hes amateur radio operator nearly 25 years enjoys photography model aviation hobbyand electronics computer programming hobby well profession FIGURE *3 5 volts1 1234567891011 0~1101 ABC0EF HJKLM U A- Ground 2N3838 PNP 47KE 122K pins H Data input receiver RED BLACK Sig Out Ground *6 MALE servo plug Figure 3 Schematic diagram havent much experience working schematic may need enlist help local electronics wizard Because its possible dam age computer make wiring error take extra care make sure circuit right FIGURE *5 Receiver Battery 48 volts I I lIli Data Output Servo FEMALE servo connector RED BLACK Gig Out Ground Ii2345878 9lo1ll2jj OiKL Figure 5 Separate battery schematic plan test heavy-duty servos may wish install independent supply power power supply inside computer good up 250 MA some larger servos could exceed rating damage December 1988 35 Data Output Servo Edge Connector Back View FEMALE servo connector Figure 4 components installed circuit board per schematic should look like wires right corner will connected servo receiver Alternate Connection Independent Battery Power Ii SLBbLY CYCLE ft SERVO RAPIDLY CYCLE ft SERVO CYCLE END-CENTER-END CYCLE IN 50 1IICROSECOND STEPS RESET UPPER/LOIR UNITS SET SERVO TO POSITION ASURE TRAISKITTER PULSE NIPTN il1SLEMSERUOiJ-QtJIT Figure 6 L software options screen Heres what youll see start program make selection menu simply press appropriate number Figure 7 R select option #7 measuring transmitter pulse length computer will display moving pointer will track movements make transmitter stick Also displayed digital read-out transmitter pulse width First would want mea sure incoming pulse length some reasons Standardizing equipment Lets say have new super transmitters mixing centering adjust ments end point adjustments exponential throw dual rates above Lets say after few months tweaking controls back transmitter things get pretty far out adjustment decide move system other plane may want set controls back factory specifications just have uniform starting point use computer measure cen ter end points transmitter chan nel readjusting channel well know certain have trans mitter adjustments back normal val ues can also quickly exacfly match two transmitters used buddy-box sys tem both instructor student have equal control throw Re-establishing settings between differ ent airplanes may have two planes operate same trans mitter need different throw centering adjustments can measure channel present setup accur ately make note measure ments can go back weeks months later re-establish same conditions determined optimum plane after transmitter has used other applications Checking stability over temperature An other use would check stability transmitter over range tempera tures perform temperature test charge up transmitter place freezer refrigerator few hours until its really cold simulates flying Min nesota January pull out freezer extend antenna fully turn Make note pulse length coming out channels Let transmitFigure 9 dont plan measure transmitter pulse length wont need make buffer amplifier circuit just test servos required solder female servo con nector directly computer plug setup can use menu options except #7 36 Model Aviation Figure 8 circuit everything hooked up except computer Never remove install connector power run risk blowing out something ter continue run coming up room temperature 20 30 minutes watch pulse length warms up Dont touch transmitter sticks during period See theres much difference between cold warm pulse length chan nel under test plan fly outside winter its good idea test entire system cold weather performance especially battery Some receivers servos have known fail cold temperatures brought equipment out warm car set up took off still warm might unpleasantly surprised something stops working no apparent re ason have observed least re ceiver quits working below 32 0F Checking stability over time check transmitter over time battery dis charges perform same test above freezing transmitter first Note pulse length transmitter first activated intervals battery runs down See theres differ encethis could explain some trim changes fly other benefits standardizing transmitter servo pulse widths manufacturers specifications exam ple transmitters set up same neutral pulse length can inter change servos receivers transmitters within systems being concerned about mixing matching equipment provided connectors mate op erating positive-pulse systems build transmitter kits repair transmitters pulse length measurement system can prove invaluable About circuit youll take look Figure #3 youll notice servo lead directly connected computer no interface just happens com puter CIA chip five-volt CMOS device generates pulses directly com patible standard RC servos No interfacing required drive servo di recfly computer arent interested measuring transmitter pulses dont need build rest circuitjust hook servo connector PC card edge connector plug computer Figure #9 Youll able use options software except Op tion #7 Measure Transmitter Pulse Length Although Commodore C-64 User Port output line has worked directly servos tested far Commodore User Port input line would work re ceivers Whether computer would work depended upon chip receiver using pulse decoder make computer work cases buf fer circuit designed condition coming signal receiver cir cuit consists two resistors PNP transistor provides gain isolation between test receiver computer buffer circuit place com puter has worked positive-pulse receiver have tested date About connector PC card edge connector labeled through 12 December 1988 37 Figure 10 pencil pointing two keys used prevent connector being installed upside down Theyre made piece plastic RC hinge mate rial CyAed place Make sure use installed properly Figure 11 find out accurately servo centers itself closely returns same end point install long pointer its output arm set up fixed pointer reference Mount servo steady position align fixed pointer the servo Se lect option #3 see closely servo returns its starting point cycles end Figure 12 Radio Shack IC experimenters board inexpensive yet rugged alternate hand-wired circuit could build circuit small box connect computer cable construction method described article simpler just reliable 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order Now fliers over world have neat inexpensive functional way protect R/C transmitters dlltr dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus Georgia 31904 404/323-2787 9am-5pm EST across top through N across bottom Notice letters G missing will fit computer either right side up upside down very careful insert properlyyou could dam age computer connecting upside down Look User Port back computer Youll see has two slots cut circuit board slots de signed mate two keys PC card edge connector responsible providing keys right location connector keys place its impossible insert connector wrong way See Figure #10 proper position ing two keysthey fit small slots between contacts con nector some reason keys arent normally supplied connector theyre almost impossible find lo cal radio store worry youll find some plastic RC hinge material cut size inserted connector care fully instant-glued place will serve ade quately other cautiondont ever plug PC card edge connector computer computer turned could get crosswise during process cause problem perhaps blowing computers internal fuse doing serious damage Building circuit circuit built 1Ath Radio Shack Experimenters Dual IC Board catalog number 276-159 see Figure #12 quarter section board cut off using Dremel tool soldered bottom row contacts PC card edge connector designed match Commodore User Port see Figure #2 edge connector has dual row con tacts 12 top 12 bottom isolated other obtained local electronics store GC Electronics part number 41-804 Amphenol part num ber 225-2-12-2-4-1-01 Cinch part num ber 251-12-30-160 use connector top bottom pins internally connected together could damage Commodore computer type con nector addition connector circuit board youll need 2N3638 PNP silicon transistor other general-purpose small signal PNP transistor specs arent critical 4700 Ohm resistor 22000 Ohm resis tor aileron extension matches radio system aileron exten sion Its convenient source male female connector have some other way coming up connectors thats OK Youll also need small amount solder wire usual small hand tools circuit board soldered directly edge connector pins per photograph Figure #2 Look carefully photo graph sure have pins connector aligned proper lands Continued page 40 38 Model Aviation 015 "~ si69 k\j wraar5a prarr r 5000r~ KVrS C0rlare- ceescrAl0 r0Od 55010 rr 500 Foaer5nOeIAflg O Iras earle is 4 fl Full Size AerObIG World Now Available n Thr 5ze MOdel Kits. TANDOF gCAL t4OUNClt4G OUR HN ANeed DeS gried Miles scale 6lpLAN 5h1 3000 5pAN A rs 15t s279~sr sier~ eOd P55 $154008 d Iuth Vas LaO e giLt Certd0rCerdrgeant Orders accelltedPersO V IANSCOVER Glow Plug Analyzers metered NI-STARTER McDaniel R/C analyzes condition glow plug time use start engine attached dualface ampmeter indicates good marginal failed plug Another innovation McDaniel R/C 1650 ma/hr recharge able battery provides 35% starting power regular nicads Dual-face ampmeter indicates plug condition attached Model 205 shown Model 201 w/charger Model 218 shown Model 217 w/charger Mode 204 020 wall stainless steel tube stainless steel spring direct connecting high temp teflon wiring beryllium copper electrode No sliding contacts corrode Positive 6-point PIgIaUCk will strip wear out 1IOV 220V AC chargers available other fine products fron McDaniel R/C see local hobby dealer contact McDaniel RIC Inc 12206 Guinevere Rd Glenn Dale MD 20769 301 464-2260 FAX 301 262-4433 Visa MC accepted take hassle out hobiry NI STARTER Palen nOV2001 & osoS ow Plug k Puen Pend NI-STOOTEOsaeo Ia0emarkof McD,nelOC Inc lO8O McDaniel RIC Inc circuit board Its easy off position clarity ease testing circuit board situated non-conven tional manner copper traces top board Should wish could build circuit small box ex tend wires computer found convenient con struction technique purposes Refer schematic diagram Figure #3 photographs guidance may need obtain assistance lo cal club electronics expert havent much experience reading schemat ics constructing electronic devices ware wiring errors could permanently damage computer especially care ful check everything twice before plug ging circuit User Port Once have parts mounted cut aileron extension half solder male female connectors circuit board per Figure #4 schematic drawing Check wiring once mis take could damage computer re quire replacement CIA chip C64 Power servo receiver taken directly Conanodore power sup ply Commodore literature says port can provide five volts up 250 mil liamperes accessory devices Some large servos will exceed current rating especially stalled cases must provide battery other separate source power servo inde pendent Commodore power supply per drawing Figure #5 could damage Commodore power supply draw excess 250 milliamperes port length time Hooking up measure incoming pulse length youll need receiver match transmitter under test Power re ceiver comes Commodore com puter supply should no problem providing required power receiv ers Ive tested have required less 50 mil liamperes current Youll have remove receiver model least un plug servo connectors battery connector receiver before start Power receiver comes back through servo lead its necessary connect switch haruess battery receiver could damage Com modore power supply leave re ceiver battery connected please remove connectors receiver before start During test youll have move leads connecting computer re ceiver servo socket channel receiver other its just easy pull receiver out model avoid fumbling inside tight quarters Once connections have made thoroughly checked plug servo servo connector plug receiver con nector channel want test Turn computer load software type LOAD PULSEMASTER8 type RUN program listing software would longer article describing sys tem Ill volunteer provide disk nominal fee cover cost disk mailer postage Its also available ready-to-use form CompuServe information near end article Operating software Once have software loaded running yopll see menu will give following options Figure #6 1 Slowly cycle servo 2 Rapidly cycle servo 3 Cycle end-center-end 4 Cycle 50 microsecond steps test ing linearity 5 Reset upper lower limits accom modate various systems 6 Set servo position 7 Measure transmitter pulse length 8 Slew servo 0 Quit select option simply enter num ber desired routine Now lets talk about what options Option #1 Slowly Cycle Servo op tion would selected servo suspected being erratic may have noticed example models control surface does smoothly follow motion transmitter stick Run routine carefully watch servo signs jitter see either jitter erratic operation likely its servo potentiometer motor fault Some servos have pots can cleaned others sealed must replaced Consult manufacturer have questions simply send suspicious servos back repairits worth cost new airplane should fail Option #2 Rapidly Cycle Servo option drives servo end its travel other Its used bura new servo few minutes see problems arise exercise servo thats sitting around unused test servo consistency using elon gated pointer connected output arm Dont overdo 30 seconds min ute should sufficient test just about servo Option #3 Cycle End-Center-End option useful want test reso lution centering servo Before option employed should use Option #5 Reset Upper Lower Limits RC system uses something other millisecond lower limit two mil liseconds upper limit Option #3 causes servo go end its normal travel other pausing momen tarily middle option becomes useful long pointer temporarily attached servo arm stationary reference pointer set up midpoint servo travel see Figure #1 1 can readily observe well servo centers have seen certain expensive coreless ser Continued page 111 40 Model Aviation Radio Technique/Myers Continued page 33 problems evident considered signif icant time comparison objec tive obtaining additional frequencies reference individuals quali fied perform tests transmitters receivers Will procedure approved FCC b will control supervise practic es persons c What packaging shipping methods used d What requirements placed upon people e Will labels placed upon transmit ters and/or receivers standardized receiver subjected major crash receiver may off frequency yet perform control placed upon previ ously accepted equipment Will AMA allow equipment assem bled repaired owner Will AMA re quire periodic tests transmitters receivers over years reference AMA Membership Man ual p 9 AMA Frequency Committee Recom mendations para 1 AMA will assume responsibility enforcement FCC regula tions will Clubs cannot afford test equipment FCC assuredly cannot pro vide enforcement other manufactur ing level good example Citizens Band ran wild very likely questions shall arise before afier implementa tion 1991 requirements What must remembered hobby participants average mod eler limited both funds time usually complies regulations imposed equipment becomes burden enjoy ment hobby will lost 1991 frequency requirements will force RC participants pay additional fees convert existing equipment buy new equipment appears trying obtain additional frequencies fliers contest field sport fliers paying right fly Myers comment AMA sought interference free frequencies replace shared frequen cies becoming unusable sport competition fliers alike due high-powered interference sharers exclusive new channels got rid high-powered sharers would appreciate presentation questions Frequency Committee re quest reply soon possible appreciation committees ef forts Myers comment copy Mr Kennedys let ter went Fred Marks FC chairman re ply went Mr Kennedy day letter received done expense Im paid AMA service nobody re imburses time materials reproduction cosrt stamp money either Pu Isemaster/Stuecker Continued page 40 vos dont seem center well some other less-expensive standard ser vos own tests see yourself servos want use Pat tern ship Option #4 Cycle SO Microsecond Steps option checks linearity servo over its entire operating range What linearity servo truly linear will move same number degrees time pulse length incremented 50 microseconds Most servos operate over one-millisecond range servo should move 20 equal-sized steps bottom limit top limit using option See Figure #1 graph ideal servo response Option #5 Reset Upper Lower Lim its software defaults standard range pulse lengths used Ace RC others millisecond 1000 mi croseconds lower limit two mil liseconds 2000 microseconds up per limit Futaba AM series however uses 81 milliseconds 181 milliseconds system limits 1310 millisec Continued page 141 December 1988 111 Editors note RC industry has begun offer RC equipment narrow band has certified independent testing laboratories FCC type acceptance meeting AMAs Guidelines 1991 oper ation Model Aviation its AMA News sec tion now regularly publishing lists such equipment first such list appeared October 1988 issue Thus ques tions being asked renders quoted George M Myers column being swered listing RMcM NEW ELECTRIC Fly Baby. great stand-way-off scale fun ship designed 05 electric power can perform take-offs touch goes aerobatics beauty yet enjoy docile slow flight easy landings Quick easy build kit includes pre cut fuselage sides tail feathers small parts hardware complete rolled plans step-by-step instructions formed landing gear windshield Electro-Combo includes kit DSC 075 Hyperthrust motor fused switch harness Tamiya connector propeller adaptor 8/4 fiberglass propeller 4 40 Span 275 Sq area 32 oz flying weight flat bottom airfoil rudder elevator motor add ailerons too HIAVEY SPECIAL COMBO PRICE $4795 YSTEMS 675 TO WER LANE BASIC KIT $24~4ORPoRATION 215-430-8645 Pu Isemaster/Stuecker Continued page 111 onds 1310 microseconds servo center Check literature system see what range pulse widths should use its other millisecond/two millisecond standard use option reset software match system re quirements Option #6 Set Servo Position option allows generate pulse known length length set num ber microseconds enter computer keyboard prevent damage servo caused excessive travel software limits range pulse widths between 500 microseconds 2500 microseconds gives error message try exceed limits servos will hit mechan ical stops certain pulse lengths within range should type pulse length greater servo can handle servo jams quickly unplug servo re type pulse length somewhere within working range servo before re connecting Deadband check want check servos deadband type number fol lowed RETURN will cause servo assume position near cen ter its travel 1500 should servos type another number slightly larger 1505 example see servo moves doesnt move youre still within servos deadband area Keep increasing number slighfly until notice servo jisst move can usually hear motor kick dif ference between last number first number typed servos deadband microseconds good servo will have tight deadband Repeat test few times Check manufacturers specs deadband see figures agree yours yours will accurate Resolution check check servos res olution secure servo stationary ob ject small vise handy tach long pointer straight piece music wire 8 10 long servos output arm Center servo above typing 1500 place stationary reference marker next end pointer Figure #11 Move servo arm other position typing 1700 exam ple type 1500 again per fect servo pointer would return exactly original position Most will off just littlethe better servo less will off Experiment few different ser vos see really better Weve found price isnt always good indica tion good resolution deadband per formance Option #7 Measure Transmitter Pulse Length option requires have receiver compatible transmitter plan test measure transmitter pulse length plug computer de sired channel receiver after discon necting other leads receiver cluding battery computer pro vides power receiver through _________________________T SERIES planes feature balsa construction Designed intermediate flyer in A-4 mind will accept 20-25 size engine luse rear exhaust angina axceptional Skyhawk performance Tha thrill jet hassles ducted fan *4000 &H Tha Proud Bird designed meet OSPRA Formula 120 rules ThIs 1/4 scale model will accept 60120 ci size engines Epoxy glees fuselage foam wing construction Full kit $150 Semi-kit also available mo wood Sia Please add 810 581 20 Tlgershark Send check MO MasterCard VISA add $3 lea add 6% esles tax Dart ExperImental two-place full sIze aircraft Top Turkey Formulal 506$55&H PARRISH AIRCRAFT 8 Scale Models ll25SW4SthTer Plantation FL 33317 December 1988 141 SPECIALISTS IN CUSTOM COX TEE DEE & REED ENGINES 020S 049 051S & 09S ALL CUSTOM & STOCK PARTS AVAILABLE INDIVIDUALLY MANY NEW PARTS FOR OLD DISCONTINUED COX ENGINES COX PROPS & GLOW HEADS COMPETITION ACCESSORIES & CUSTOMIZED K&B ENGINES ALSO COMPLETE LINE OF RACING PARTS - GLO-BEE FIREBALL & K&B PLUGS SOLID LINES RACING WHEELS QUICK FILLS ETC WE ALSO STOCK CARBON FIBER KLOTZ OIL LATEX & SILICONE FUEL TUBING PEN BLADDER MATERIALS & HARDTO-FIND HARDWARE ESPECIALLY 2-56 & 3-48 SIZES COILS CONDENSERS NGK & STITT PLUGS SILK 12 COLORS QUALITY DOPE BRUSHES 5 & 7 LOOP RUBBER BANDS KSB SEELIG & IGNITION TIMERS GAS & DIESEL FUEL TUBING TRANSISTOR IGNITION SYSTEMS RESISTOR HI-TENSION LEADS 1/2A TEXACO PLAYBOY SR KIT 1/2A TEXACO ENGINES & PARTS EVERYTHING YOU NEED FOR OLD TIMER EVENTS servo connector Turn transmitter select op tion will notice will hor izontal scale drawn computer screen calibrated milliseconds moving pointer follows motion transmitter stick see Figure #7 prefer digital read-out pulse length theres also numeric read out measuring incoming pulse length nearest microsecond option serves two purposes can used measure end points stick travel also can used see well transmit ter sticks return neutral after theyve released Let stick snap back neutral take reading slowly return stick neutral see get same reading Move stick opposite direction same good set sticks will typi cally return within few microseconds same neutral setting time either direction measurement solved problem originally thought servo linkage problem systems plane would stay trim problem finally found sticky stick transmitter didnt al ways return same spot after re leased word cautionif select Op tion #7 have receiver connected computer have receiver connected no transmitter running computer will appear lock up nor mal Whats happening computer waiting pulse come User Port get out locked-up mode hold down Run/Stop key tap Re store keys Option #8 Slew Servo allows slowly move servo through its range using arrow keys lower right side keyboard change servo output arm position moving output arm position using option given read-out near est microsecond pulse length servo receiving option can used check servo linearity have large pointer con nected servo output arm protrac tor other means accurately determin ing pointer position could plot curve pulse length horizontal axis servo rotation vertical axis servo truly linear curve plot will turn out perfectly straight line Figure #1 have about hours work $10 can build transmitter checker automated servo testing setup using handful parts inex pensive home computer dont hap pen have Commodore C-64 computer should someone within club does computerized radio/servo checker could make interesting group project something club could make available service during meet ing rainy weekend give mem bers means checking RC systems hope find useful tool Parts List 1 ea Aileron Connector match radio sys tem 1 ea PC Card Edge Connector match Com modore C64* IC Electromcs part #41-804 #41-816 Amphenol part #225-2-12-2-4-1-01 Cinch part #251-12-30-160 1 ea Experimenters Dual IC Board Radio Shack catalog #276-159 1 ea 2N3638 MPS2907 other PNP silicon general purpose small signal transistor Radio Shack catalog #276-2023 1 ea 4700 Ohm A-watt resistor Radio Shack catalog #271-1330 1 ca 22000 Ohm A-watt resistor Radio Shack Catalog #271-1339 Solder wire miscellaneous small hand tools *The cost PC card edge connector lo cal electronics dealer approximately $375 Its also listed part number 12/245E Jameco Electronics catalog costs $149 can reach Jameco Electronics 415 592-8097 write 1355 Shoreway Rd Belmont CA 94002 Janieco has $2000 minimum order may want get few friends together prepare bulk purchase Jameco also requires 5% handling fee $100 minimum Call Ja meco cant find connector locally have handful connectors Ill pro vide $500 first-come basis until supply runs out Please include pre-addressed stamped envelope orders case check has returned software project available Commodore diskette au thor CompuServe No hard copy printout available diskette can obtained sending $500 check money order cover cost disk mailer postage Bernard L Stuecker 2433 Carey Ln Vienna VA 22180 CompuServe subscribers can GO MOD ELNET find program software dowaloading Library 11 com mand BRO KEYSERVO can get CompuServe subscription information calling CompuServe 800 848-8199 AMA member would like free CompuServe subscription kit write Doug Pratt AMA HQ 1810 Samuel Morse Dr Reston VA 22090 ModelNet AMAs computer bulletin board service need information about project please sure include pre addressed stamped envelope query address above RC Soaring/Blakeslee Continued page 43 planes DG-100/428/132/229 DG-200 Acroracer/3 75/[ 106/ 128]/293 DG-200/ 428/119/257 DG-l00/428/143/250 DG 202/500/[139/16 11/216 first DG-100 now 11 years old wings DG-200 conventional con struction 2mm balsa sheeting steel blade joiners others have blue foam cores covered fiberglass obechi made using vacuum-bag technique DG-202 50 142 Model Aviation OUR REV-UP INVENTORY AVERAGES OVER 9000 PROPS I! CALL FOR IMMEDIATE SHIPMENT ON VISA OR MASTERCARD OLD TIMER SUPPLIES ORDER BY MAIL OR PHONE 619728-4365 SORRY NO COD VISA & MASTERCARD WELCOME DEALER INQUIRES INVITED MINIMUM MERCHANDISE ORDER $1000 SHIPPING & HANDLING FEE $150 E ADD $100 auinrn IAIITLJIId 2A UfI R5
Edition: Model Aviation - 1988/12
Page Numbers: 34, 35, 36, 37, 38, 40, 111, 141, 142
Pulsemaster 64 simple circuit use Commodore C-64 computer can provide wealth information about performance servos transmitter D E 6 R E E S R 0 T T 0 N Bernard L Stuecker 40 30 20 10 0 10 20 30 40 Ideal Servo Response Figure *1 PULSES Theyre heartbeat nearly modem RC systems Theyre used tell servo what position assume Theyre sent out transmitter serial stream channel #1 first channel #2 second until theyve transmitted After last channels sent transmit ter sends out sync pulse tell re ceiver its through starts process over again typical system length pulse varies between millisecond two milliseconds depending upon posi tion stick associated chan nel Whats millisecond Its thousandth second Its 1000 microseconds Its pretty short period time typical sevenchannel transmitter can send out pulses necessary control seven servos about 22 milliseconds /45th second cluding some time electronic house keeping receiver takes stream pulses sorts out sending #1 pulse #1 servo #2 pulse #2 servo servo examines pulse receiver just sent rotates its output arm appropriate location based upon length pulse pulse example millisec ond long servo will rotate its counterclockwise position pulse two milliseconds long servo will rotate its clockwise position pulse 15 milliseconds long servo will go its center position pulse length somewhere between arm will rotate intermediate position depending incoming pulse length what mean proportional control See Figure #1 graph what ideal servo will servos same Some have much better resolution deadband others price isnt always comrnensu rate performance areas 1000 1200 1400 1600 1800 2000 PULSE LENGTH microseconds Figure 1 Servo linearity curve curve ideal servo Notice servo out put arm 45O input pulse length 1000 microseconds output arm 45O input pulse length 2000 microseconds practical world straight line could somewhat curved depending linearity servos internal electronics us interested RC electronics pulses have always source trouble Until recently its difficult accurately measure equipment available RCers 1985 Kenneth Jesser published article Ra dio Control Modeler magazine entitled Digital Pulse Meter article de scribed build inexpensive instru ment designed accurately measure length pulses Soon after article published Ace RC started selling unit called Datamaster similar Jessers origi nal Digital Pulse Meter make Datamaster versatile Ace added built-in manually controlled pulse generator AM transmitter decoder addition internal pulse generator AM transmitter decoder Datamaster came self-contained unit could used either test individual servo transmitter have Commodore C-64 com puter knowledge electronics lit tle soldering skill can build simple inexpensive circuit will perform same tests Ace Datamaster Total cost components should der $1000 computer can used replace three individual instruments digi tal pulse meter manually controlled pulse 34 Model Aviation Figure 2 section Radio Shack experimenters circuit board text has part number soldered pins connector plugged computer Note positions lands copper traces circuit board respect pins connector generator automatic servo cycler As bonus computer can measure coming pulse length accurately original digital pulse meter can mea sure pulse length nearest microsec ond can also generate high-preci sion pulses operate test automati cally cycle servo circuit associated software about describe makes use 6526 Complex Interface Adapter chip CIA inside Commodore computer generate outgoing pulses time incom ing pulses chip has hardware timers counter circuits built allow measurement time intervals between microsecond 70 seconds mi crosecond resolution timers oper ated crystal-controlled clock ac curacy stability timers out standing Fortunately us designers Commodore C-64 computer made possible access chip through User Port back computer Because output lines comput ers User Port can employed generate very accurately timed pulses can use pulses operate servo check its resolution deadband centering end points linearityfeatures interesting sport flier crucial Pattern competitor can also use computergenerated pulses under control appro priate software cause servo very slowly creep through its range check defective spots potentiometer pot motor commutator defective spots generally manifest themselves jitter output arm servo servo slowly cycled end its travel otherand usually caused either wear corrosion dirt finds its way motor pot com puter can also rapidly automatically cy cle servo end its travel other can make servo arm move specific position under con trol operator other interesting features can implemented using computers internal pulse generator lets examine other side chip al lows computer accurately measure coming pulse length About Author Bernie Stuecker has involved RC since 1979 member Northern Virginia Radio Control Club Hes past president NVRC currently edits club newsletter Feedback has circulation about 235 copies per month Bernies electronics engineer pro fession also holds amateur radio station license call sign K4XY Hes amateur radio operator nearly 25 years enjoys photography model aviation hobbyand electronics computer programming hobby well profession FIGURE *3 5 volts1 1234567891011 0~1101 ABC0EF HJKLM U A- Ground 2N3838 PNP 47KE 122K pins H Data input receiver RED BLACK Sig Out Ground *6 MALE servo plug Figure 3 Schematic diagram havent much experience working schematic may need enlist help local electronics wizard Because its possible dam age computer make wiring error take extra care make sure circuit right FIGURE *5 Receiver Battery 48 volts I I lIli Data Output Servo FEMALE servo connector RED BLACK Gig Out Ground Ii2345878 9lo1ll2jj OiKL Figure 5 Separate battery schematic plan test heavy-duty servos may wish install independent supply power power supply inside computer good up 250 MA some larger servos could exceed rating damage December 1988 35 Data Output Servo Edge Connector Back View FEMALE servo connector Figure 4 components installed circuit board per schematic should look like wires right corner will connected servo receiver Alternate Connection Independent Battery Power Ii SLBbLY CYCLE ft SERVO RAPIDLY CYCLE ft SERVO CYCLE END-CENTER-END CYCLE IN 50 1IICROSECOND STEPS RESET UPPER/LOIR UNITS SET SERVO TO POSITION ASURE TRAISKITTER PULSE NIPTN il1SLEMSERUOiJ-QtJIT Figure 6 L software options screen Heres what youll see start program make selection menu simply press appropriate number Figure 7 R select option #7 measuring transmitter pulse length computer will display moving pointer will track movements make transmitter stick Also displayed digital read-out transmitter pulse width First would want mea sure incoming pulse length some reasons Standardizing equipment Lets say have new super transmitters mixing centering adjust ments end point adjustments exponential throw dual rates above Lets say after few months tweaking controls back transmitter things get pretty far out adjustment decide move system other plane may want set controls back factory specifications just have uniform starting point use computer measure cen ter end points transmitter chan nel readjusting channel well know certain have trans mitter adjustments back normal val ues can also quickly exacfly match two transmitters used buddy-box sys tem both instructor student have equal control throw Re-establishing settings between differ ent airplanes may have two planes operate same trans mitter need different throw centering adjustments can measure channel present setup accur ately make note measure ments can go back weeks months later re-establish same conditions determined optimum plane after transmitter has used other applications Checking stability over temperature An other use would check stability transmitter over range tempera tures perform temperature test charge up transmitter place freezer refrigerator few hours until its really cold simulates flying Min nesota January pull out freezer extend antenna fully turn Make note pulse length coming out channels Let transmitFigure 9 dont plan measure transmitter pulse length wont need make buffer amplifier circuit just test servos required solder female servo con nector directly computer plug setup can use menu options except #7 36 Model Aviation Figure 8 circuit everything hooked up except computer Never remove install connector power run risk blowing out something ter continue run coming up room temperature 20 30 minutes watch pulse length warms up Dont touch transmitter sticks during period See theres much difference between cold warm pulse length chan nel under test plan fly outside winter its good idea test entire system cold weather performance especially battery Some receivers servos have known fail cold temperatures brought equipment out warm car set up took off still warm might unpleasantly surprised something stops working no apparent re ason have observed least re ceiver quits working below 32 0F Checking stability over time check transmitter over time battery dis charges perform same test above freezing transmitter first Note pulse length transmitter first activated intervals battery runs down See theres differ encethis could explain some trim changes fly other benefits standardizing transmitter servo pulse widths manufacturers specifications exam ple transmitters set up same neutral pulse length can inter change servos receivers transmitters within systems being concerned about mixing matching equipment provided connectors mate op erating positive-pulse systems build transmitter kits repair transmitters pulse length measurement system can prove invaluable About circuit youll take look Figure #3 youll notice servo lead directly connected computer no interface just happens com puter CIA chip five-volt CMOS device generates pulses directly com patible standard RC servos No interfacing required drive servo di recfly computer arent interested measuring transmitter pulses dont need build rest circuitjust hook servo connector PC card edge connector plug computer Figure #9 Youll able use options software except Op tion #7 Measure Transmitter Pulse Length Although Commodore C-64 User Port output line has worked directly servos tested far Commodore User Port input line would work re ceivers Whether computer would work depended upon chip receiver using pulse decoder make computer work cases buf fer circuit designed condition coming signal receiver cir cuit consists two resistors PNP transistor provides gain isolation between test receiver computer buffer circuit place com puter has worked positive-pulse receiver have tested date About connector PC card edge connector labeled through 12 December 1988 37 Figure 10 pencil pointing two keys used prevent connector being installed upside down Theyre made piece plastic RC hinge mate rial CyAed place Make sure use installed properly Figure 11 find out accurately servo centers itself closely returns same end point install long pointer its output arm set up fixed pointer reference Mount servo steady position align fixed pointer the servo Se lect option #3 see closely servo returns its starting point cycles end Figure 12 Radio Shack IC experimenters board inexpensive yet rugged alternate hand-wired circuit could build circuit small box connect computer cable construction method described article simpler just reliable 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order Now fliers over world have neat inexpensive functional way protect R/C transmitters dlltr dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus Georgia 31904 404/323-2787 9am-5pm EST across top through N across bottom Notice letters G missing will fit computer either right side up upside down very careful insert properlyyou could dam age computer connecting upside down Look User Port back computer Youll see has two slots cut circuit board slots de signed mate two keys PC card edge connector responsible providing keys right location connector keys place its impossible insert connector wrong way See Figure #10 proper position ing two keysthey fit small slots between contacts con nector some reason keys arent normally supplied connector theyre almost impossible find lo cal radio store worry youll find some plastic RC hinge material cut size inserted connector care fully instant-glued place will serve ade quately other cautiondont ever plug PC card edge connector computer computer turned could get crosswise during process cause problem perhaps blowing computers internal fuse doing serious damage Building circuit circuit built 1Ath Radio Shack Experimenters Dual IC Board catalog number 276-159 see Figure #12 quarter section board cut off using Dremel tool soldered bottom row contacts PC card edge connector designed match Commodore User Port see Figure #2 edge connector has dual row con tacts 12 top 12 bottom isolated other obtained local electronics store GC Electronics part number 41-804 Amphenol part num ber 225-2-12-2-4-1-01 Cinch part num ber 251-12-30-160 use connector top bottom pins internally connected together could damage Commodore computer type con nector addition connector circuit board youll need 2N3638 PNP silicon transistor other general-purpose small signal PNP transistor specs arent critical 4700 Ohm resistor 22000 Ohm resis tor aileron extension matches radio system aileron exten sion Its convenient source male female connector have some other way coming up connectors thats OK Youll also need small amount solder wire usual small hand tools circuit board soldered directly edge connector pins per photograph Figure #2 Look carefully photo graph sure have pins connector aligned proper lands Continued page 40 38 Model Aviation 015 "~ si69 k\j wraar5a prarr r 5000r~ KVrS C0rlare- ceescrAl0 r0Od 55010 rr 500 Foaer5nOeIAflg O Iras earle is 4 fl Full Size AerObIG World Now Available n Thr 5ze MOdel Kits. TANDOF gCAL t4OUNClt4G OUR HN ANeed DeS gried Miles scale 6lpLAN 5h1 3000 5pAN A rs 15t s279~sr sier~ eOd P55 $154008 d Iuth Vas LaO e giLt Certd0rCerdrgeant Orders accelltedPersO V IANSCOVER Glow Plug Analyzers metered NI-STARTER McDaniel R/C analyzes condition glow plug time use start engine attached dualface ampmeter indicates good marginal failed plug Another innovation McDaniel R/C 1650 ma/hr recharge able battery provides 35% starting power regular nicads Dual-face ampmeter indicates plug condition attached Model 205 shown Model 201 w/charger Model 218 shown Model 217 w/charger Mode 204 020 wall stainless steel tube stainless steel spring direct connecting high temp teflon wiring beryllium copper electrode No sliding contacts corrode Positive 6-point PIgIaUCk will strip wear out 1IOV 220V AC chargers available other fine products fron McDaniel R/C see local hobby dealer contact McDaniel RIC Inc 12206 Guinevere Rd Glenn Dale MD 20769 301 464-2260 FAX 301 262-4433 Visa MC accepted take hassle out hobiry NI STARTER Palen nOV2001 & osoS ow Plug k Puen Pend NI-STOOTEOsaeo Ia0emarkof McD,nelOC Inc lO8O McDaniel RIC Inc circuit board Its easy off position clarity ease testing circuit board situated non-conven tional manner copper traces top board Should wish could build circuit small box ex tend wires computer found convenient con struction technique purposes Refer schematic diagram Figure #3 photographs guidance may need obtain assistance lo cal club electronics expert havent much experience reading schemat ics constructing electronic devices ware wiring errors could permanently damage computer especially care ful check everything twice before plug ging circuit User Port Once have parts mounted cut aileron extension half solder male female connectors circuit board per Figure #4 schematic drawing Check wiring once mis take could damage computer re quire replacement CIA chip C64 Power servo receiver taken directly Conanodore power sup ply Commodore literature says port can provide five volts up 250 mil liamperes accessory devices Some large servos will exceed current rating especially stalled cases must provide battery other separate source power servo inde pendent Commodore power supply per drawing Figure #5 could damage Commodore power supply draw excess 250 milliamperes port length time Hooking up measure incoming pulse length youll need receiver match transmitter under test Power re ceiver comes Commodore com puter supply should no problem providing required power receiv ers Ive tested have required less 50 mil liamperes current Youll have remove receiver model least un plug servo connectors battery connector receiver before start Power receiver comes back through servo lead its necessary connect switch haruess battery receiver could damage Com modore power supply leave re ceiver battery connected please remove connectors receiver before start During test youll have move leads connecting computer re ceiver servo socket channel receiver other its just easy pull receiver out model avoid fumbling inside tight quarters Once connections have made thoroughly checked plug servo servo connector plug receiver con nector channel want test Turn computer load software type LOAD PULSEMASTER8 type RUN program listing software would longer article describing sys tem Ill volunteer provide disk nominal fee cover cost disk mailer postage Its also available ready-to-use form CompuServe information near end article Operating software Once have software loaded running yopll see menu will give following options Figure #6 1 Slowly cycle servo 2 Rapidly cycle servo 3 Cycle end-center-end 4 Cycle 50 microsecond steps test ing linearity 5 Reset upper lower limits accom modate various systems 6 Set servo position 7 Measure transmitter pulse length 8 Slew servo 0 Quit select option simply enter num ber desired routine Now lets talk about what options Option #1 Slowly Cycle Servo op tion would selected servo suspected being erratic may have noticed example models control surface does smoothly follow motion transmitter stick Run routine carefully watch servo signs jitter see either jitter erratic operation likely its servo potentiometer motor fault Some servos have pots can cleaned others sealed must replaced Consult manufacturer have questions simply send suspicious servos back repairits worth cost new airplane should fail Option #2 Rapidly Cycle Servo option drives servo end its travel other Its used bura new servo few minutes see problems arise exercise servo thats sitting around unused test servo consistency using elon gated pointer connected output arm Dont overdo 30 seconds min ute should sufficient test just about servo Option #3 Cycle End-Center-End option useful want test reso lution centering servo Before option employed should use Option #5 Reset Upper Lower Limits RC system uses something other millisecond lower limit two mil liseconds upper limit Option #3 causes servo go end its normal travel other pausing momen tarily middle option becomes useful long pointer temporarily attached servo arm stationary reference pointer set up midpoint servo travel see Figure #1 1 can readily observe well servo centers have seen certain expensive coreless ser Continued page 111 40 Model Aviation Radio Technique/Myers Continued page 33 problems evident considered signif icant time comparison objec tive obtaining additional frequencies reference individuals quali fied perform tests transmitters receivers Will procedure approved FCC b will control supervise practic es persons c What packaging shipping methods used d What requirements placed upon people e Will labels placed upon transmit ters and/or receivers standardized receiver subjected major crash receiver may off frequency yet perform control placed upon previ ously accepted equipment Will AMA allow equipment assem bled repaired owner Will AMA re quire periodic tests transmitters receivers over years reference AMA Membership Man ual p 9 AMA Frequency Committee Recom mendations para 1 AMA will assume responsibility enforcement FCC regula tions will Clubs cannot afford test equipment FCC assuredly cannot pro vide enforcement other manufactur ing level good example Citizens Band ran wild very likely questions shall arise before afier implementa tion 1991 requirements What must remembered hobby participants average mod eler limited both funds time usually complies regulations imposed equipment becomes burden enjoy ment hobby will lost 1991 frequency requirements will force RC participants pay additional fees convert existing equipment buy new equipment appears trying obtain additional frequencies fliers contest field sport fliers paying right fly Myers comment AMA sought interference free frequencies replace shared frequen cies becoming unusable sport competition fliers alike due high-powered interference sharers exclusive new channels got rid high-powered sharers would appreciate presentation questions Frequency Committee re quest reply soon possible appreciation committees ef forts Myers comment copy Mr Kennedys let ter went Fred Marks FC chairman re ply went Mr Kennedy day letter received done expense Im paid AMA service nobody re imburses time materials reproduction cosrt stamp money either Pu Isemaster/Stuecker Continued page 40 vos dont seem center well some other less-expensive standard ser vos own tests see yourself servos want use Pat tern ship Option #4 Cycle SO Microsecond Steps option checks linearity servo over its entire operating range What linearity servo truly linear will move same number degrees time pulse length incremented 50 microseconds Most servos operate over one-millisecond range servo should move 20 equal-sized steps bottom limit top limit using option See Figure #1 graph ideal servo response Option #5 Reset Upper Lower Lim its software defaults standard range pulse lengths used Ace RC others millisecond 1000 mi croseconds lower limit two mil liseconds 2000 microseconds up per limit Futaba AM series however uses 81 milliseconds 181 milliseconds system limits 1310 millisec Continued page 141 December 1988 111 Editors note RC industry has begun offer RC equipment narrow band has certified independent testing laboratories FCC type acceptance meeting AMAs Guidelines 1991 oper ation Model Aviation its AMA News sec tion now regularly publishing lists such equipment first such list appeared October 1988 issue Thus ques tions being asked renders quoted George M Myers column being swered listing RMcM NEW ELECTRIC Fly Baby. great stand-way-off scale fun ship designed 05 electric power can perform take-offs touch goes aerobatics beauty yet enjoy docile slow flight easy landings Quick easy build kit includes pre cut fuselage sides tail feathers small parts hardware complete rolled plans step-by-step instructions formed landing gear windshield Electro-Combo includes kit DSC 075 Hyperthrust motor fused switch harness Tamiya connector propeller adaptor 8/4 fiberglass propeller 4 40 Span 275 Sq area 32 oz flying weight flat bottom airfoil rudder elevator motor add ailerons too HIAVEY SPECIAL COMBO PRICE $4795 YSTEMS 675 TO WER LANE BASIC KIT $24~4ORPoRATION 215-430-8645 Pu Isemaster/Stuecker Continued page 111 onds 1310 microseconds servo center Check literature system see what range pulse widths should use its other millisecond/two millisecond standard use option reset software match system re quirements Option #6 Set Servo Position option allows generate pulse known length length set num ber microseconds enter computer keyboard prevent damage servo caused excessive travel software limits range pulse widths between 500 microseconds 2500 microseconds gives error message try exceed limits servos will hit mechan ical stops certain pulse lengths within range should type pulse length greater servo can handle servo jams quickly unplug servo re type pulse length somewhere within working range servo before re connecting Deadband check want check servos deadband type number fol lowed RETURN will cause servo assume position near cen ter its travel 1500 should servos type another number slightly larger 1505 example see servo moves doesnt move youre still within servos deadband area Keep increasing number slighfly until notice servo jisst move can usually hear motor kick dif ference between last number first number typed servos deadband microseconds good servo will have tight deadband Repeat test few times Check manufacturers specs deadband see figures agree yours yours will accurate Resolution check check servos res olution secure servo stationary ob ject small vise handy tach long pointer straight piece music wire 8 10 long servos output arm Center servo above typing 1500 place stationary reference marker next end pointer Figure #11 Move servo arm other position typing 1700 exam ple type 1500 again per fect servo pointer would return exactly original position Most will off just littlethe better servo less will off Experiment few different ser vos see really better Weve found price isnt always good indica tion good resolution deadband per formance Option #7 Measure Transmitter Pulse Length option requires have receiver compatible transmitter plan test measure transmitter pulse length plug computer de sired channel receiver after discon necting other leads receiver cluding battery computer pro vides power receiver through _________________________T SERIES planes feature balsa construction Designed intermediate flyer in A-4 mind will accept 20-25 size engine luse rear exhaust angina axceptional Skyhawk performance Tha thrill jet hassles ducted fan *4000 &H Tha Proud Bird designed meet OSPRA Formula 120 rules ThIs 1/4 scale model will accept 60120 ci size engines Epoxy glees fuselage foam wing construction Full kit $150 Semi-kit also available mo wood Sia Please add 810 581 20 Tlgershark Send check MO MasterCard VISA add $3 lea add 6% esles tax Dart ExperImental two-place full sIze aircraft Top Turkey Formulal 506$55&H PARRISH AIRCRAFT 8 Scale Models ll25SW4SthTer Plantation FL 33317 December 1988 141 SPECIALISTS IN CUSTOM COX TEE DEE & REED ENGINES 020S 049 051S & 09S ALL CUSTOM & STOCK PARTS AVAILABLE INDIVIDUALLY MANY NEW PARTS FOR OLD DISCONTINUED COX ENGINES COX PROPS & GLOW HEADS COMPETITION ACCESSORIES & CUSTOMIZED K&B ENGINES ALSO COMPLETE LINE OF RACING PARTS - GLO-BEE FIREBALL & K&B PLUGS SOLID LINES RACING WHEELS QUICK FILLS ETC WE ALSO STOCK CARBON FIBER KLOTZ OIL LATEX & SILICONE FUEL TUBING PEN BLADDER MATERIALS & HARDTO-FIND HARDWARE ESPECIALLY 2-56 & 3-48 SIZES COILS CONDENSERS NGK & STITT PLUGS SILK 12 COLORS QUALITY DOPE BRUSHES 5 & 7 LOOP RUBBER BANDS KSB SEELIG & IGNITION TIMERS GAS & DIESEL FUEL TUBING TRANSISTOR IGNITION SYSTEMS RESISTOR HI-TENSION LEADS 1/2A TEXACO PLAYBOY SR KIT 1/2A TEXACO ENGINES & PARTS EVERYTHING YOU NEED FOR OLD TIMER EVENTS servo connector Turn transmitter select op tion will notice will hor izontal scale drawn computer screen calibrated milliseconds moving pointer follows motion transmitter stick see Figure #7 prefer digital read-out pulse length theres also numeric read out measuring incoming pulse length nearest microsecond option serves two purposes can used measure end points stick travel also can used see well transmit ter sticks return neutral after theyve released Let stick snap back neutral take reading slowly return stick neutral see get same reading Move stick opposite direction same good set sticks will typi cally return within few microseconds same neutral setting time either direction measurement solved problem originally thought servo linkage problem systems plane would stay trim problem finally found sticky stick transmitter didnt al ways return same spot after re leased word cautionif select Op tion #7 have receiver connected computer have receiver connected no transmitter running computer will appear lock up nor mal Whats happening computer waiting pulse come User Port get out locked-up mode hold down Run/Stop key tap Re store keys Option #8 Slew Servo allows slowly move servo through its range using arrow keys lower right side keyboard change servo output arm position moving output arm position using option given read-out near est microsecond pulse length servo receiving option can used check servo linearity have large pointer con nected servo output arm protrac tor other means accurately determin ing pointer position could plot curve pulse length horizontal axis servo rotation vertical axis servo truly linear curve plot will turn out perfectly straight line Figure #1 have about hours work $10 can build transmitter checker automated servo testing setup using handful parts inex pensive home computer dont hap pen have Commodore C-64 computer should someone within club does computerized radio/servo checker could make interesting group project something club could make available service during meet ing rainy weekend give mem bers means checking RC systems hope find useful tool Parts List 1 ea Aileron Connector match radio sys tem 1 ea PC Card Edge Connector match Com modore C64* IC Electromcs part #41-804 #41-816 Amphenol part #225-2-12-2-4-1-01 Cinch part #251-12-30-160 1 ea Experimenters Dual IC Board Radio Shack catalog #276-159 1 ea 2N3638 MPS2907 other PNP silicon general purpose small signal transistor Radio Shack catalog #276-2023 1 ea 4700 Ohm A-watt resistor Radio Shack catalog #271-1330 1 ca 22000 Ohm A-watt resistor Radio Shack Catalog #271-1339 Solder wire miscellaneous small hand tools *The cost PC card edge connector lo cal electronics dealer approximately $375 Its also listed part number 12/245E Jameco Electronics catalog costs $149 can reach Jameco Electronics 415 592-8097 write 1355 Shoreway Rd Belmont CA 94002 Janieco has $2000 minimum order may want get few friends together prepare bulk purchase Jameco also requires 5% handling fee $100 minimum Call Ja meco cant find connector locally have handful connectors Ill pro vide $500 first-come basis until supply runs out Please include pre-addressed stamped envelope orders case check has returned software project available Commodore diskette au thor CompuServe No hard copy printout available diskette can obtained sending $500 check money order cover cost disk mailer postage Bernard L Stuecker 2433 Carey Ln Vienna VA 22180 CompuServe subscribers can GO MOD ELNET find program software dowaloading Library 11 com mand BRO KEYSERVO can get CompuServe subscription information calling CompuServe 800 848-8199 AMA member would like free CompuServe subscription kit write Doug Pratt AMA HQ 1810 Samuel Morse Dr Reston VA 22090 ModelNet AMAs computer bulletin board service need information about project please sure include pre addressed stamped envelope query address above RC Soaring/Blakeslee Continued page 43 planes DG-100/428/132/229 DG-200 Acroracer/3 75/[ 106/ 128]/293 DG-200/ 428/119/257 DG-l00/428/143/250 DG 202/500/[139/16 11/216 first DG-100 now 11 years old wings DG-200 conventional con struction 2mm balsa sheeting steel blade joiners others have blue foam cores covered fiberglass obechi made using vacuum-bag technique DG-202 50 142 Model Aviation OUR REV-UP INVENTORY AVERAGES OVER 9000 PROPS I! CALL FOR IMMEDIATE SHIPMENT ON VISA OR MASTERCARD OLD TIMER SUPPLIES ORDER BY MAIL OR PHONE 619728-4365 SORRY NO COD VISA & MASTERCARD WELCOME DEALER INQUIRES INVITED MINIMUM MERCHANDISE ORDER $1000 SHIPPING & HANDLING FEE $150 E ADD $100 auinrn IAIITLJIId 2A UfI R5
Edition: Model Aviation - 1988/12
Page Numbers: 34, 35, 36, 37, 38, 40, 111, 141, 142
Pulsemaster 64 simple circuit use Commodore C-64 computer can provide wealth information about performance servos transmitter D E 6 R E E S R 0 T T 0 N Bernard L Stuecker 40 30 20 10 0 10 20 30 40 Ideal Servo Response Figure *1 PULSES Theyre heartbeat nearly modem RC systems Theyre used tell servo what position assume Theyre sent out transmitter serial stream channel #1 first channel #2 second until theyve transmitted After last channels sent transmit ter sends out sync pulse tell re ceiver its through starts process over again typical system length pulse varies between millisecond two milliseconds depending upon posi tion stick associated chan nel Whats millisecond Its thousandth second Its 1000 microseconds Its pretty short period time typical sevenchannel transmitter can send out pulses necessary control seven servos about 22 milliseconds /45th second cluding some time electronic house keeping receiver takes stream pulses sorts out sending #1 pulse #1 servo #2 pulse #2 servo servo examines pulse receiver just sent rotates its output arm appropriate location based upon length pulse pulse example millisec ond long servo will rotate its counterclockwise position pulse two milliseconds long servo will rotate its clockwise position pulse 15 milliseconds long servo will go its center position pulse length somewhere between arm will rotate intermediate position depending incoming pulse length what mean proportional control See Figure #1 graph what ideal servo will servos same Some have much better resolution deadband others price isnt always comrnensu rate performance areas 1000 1200 1400 1600 1800 2000 PULSE LENGTH microseconds Figure 1 Servo linearity curve curve ideal servo Notice servo out put arm 45O input pulse length 1000 microseconds output arm 45O input pulse length 2000 microseconds practical world straight line could somewhat curved depending linearity servos internal electronics us interested RC electronics pulses have always source trouble Until recently its difficult accurately measure equipment available RCers 1985 Kenneth Jesser published article Ra dio Control Modeler magazine entitled Digital Pulse Meter article de scribed build inexpensive instru ment designed accurately measure length pulses Soon after article published Ace RC started selling unit called Datamaster similar Jessers origi nal Digital Pulse Meter make Datamaster versatile Ace added built-in manually controlled pulse generator AM transmitter decoder addition internal pulse generator AM transmitter decoder Datamaster came self-contained unit could used either test individual servo transmitter have Commodore C-64 com puter knowledge electronics lit tle soldering skill can build simple inexpensive circuit will perform same tests Ace Datamaster Total cost components should der $1000 computer can used replace three individual instruments digi tal pulse meter manually controlled pulse 34 Model Aviation Figure 2 section Radio Shack experimenters circuit board text has part number soldered pins connector plugged computer Note positions lands copper traces circuit board respect pins connector generator automatic servo cycler As bonus computer can measure coming pulse length accurately original digital pulse meter can mea sure pulse length nearest microsec ond can also generate high-preci sion pulses operate test automati cally cycle servo circuit associated software about describe makes use 6526 Complex Interface Adapter chip CIA inside Commodore computer generate outgoing pulses time incom ing pulses chip has hardware timers counter circuits built allow measurement time intervals between microsecond 70 seconds mi crosecond resolution timers oper ated crystal-controlled clock ac curacy stability timers out standing Fortunately us designers Commodore C-64 computer made possible access chip through User Port back computer Because output lines comput ers User Port can employed generate very accurately timed pulses can use pulses operate servo check its resolution deadband centering end points linearityfeatures interesting sport flier crucial Pattern competitor can also use computergenerated pulses under control appro priate software cause servo very slowly creep through its range check defective spots potentiometer pot motor commutator defective spots generally manifest themselves jitter output arm servo servo slowly cycled end its travel otherand usually caused either wear corrosion dirt finds its way motor pot com puter can also rapidly automatically cy cle servo end its travel other can make servo arm move specific position under con trol operator other interesting features can implemented using computers internal pulse generator lets examine other side chip al lows computer accurately measure coming pulse length About Author Bernie Stuecker has involved RC since 1979 member Northern Virginia Radio Control Club Hes past president NVRC currently edits club newsletter Feedback has circulation about 235 copies per month Bernies electronics engineer pro fession also holds amateur radio station license call sign K4XY Hes amateur radio operator nearly 25 years enjoys photography model aviation hobbyand electronics computer programming hobby well profession FIGURE *3 5 volts1 1234567891011 0~1101 ABC0EF HJKLM U A- Ground 2N3838 PNP 47KE 122K pins H Data input receiver RED BLACK Sig Out Ground *6 MALE servo plug Figure 3 Schematic diagram havent much experience working schematic may need enlist help local electronics wizard Because its possible dam age computer make wiring error take extra care make sure circuit right FIGURE *5 Receiver Battery 48 volts I I lIli Data Output Servo FEMALE servo connector RED BLACK Gig Out Ground Ii2345878 9lo1ll2jj OiKL Figure 5 Separate battery schematic plan test heavy-duty servos may wish install independent supply power power supply inside computer good up 250 MA some larger servos could exceed rating damage December 1988 35 Data Output Servo Edge Connector Back View FEMALE servo connector Figure 4 components installed circuit board per schematic should look like wires right corner will connected servo receiver Alternate Connection Independent Battery Power Ii SLBbLY CYCLE ft SERVO RAPIDLY CYCLE ft SERVO CYCLE END-CENTER-END CYCLE IN 50 1IICROSECOND STEPS RESET UPPER/LOIR UNITS SET SERVO TO POSITION ASURE TRAISKITTER PULSE NIPTN il1SLEMSERUOiJ-QtJIT Figure 6 L software options screen Heres what youll see start program make selection menu simply press appropriate number Figure 7 R select option #7 measuring transmitter pulse length computer will display moving pointer will track movements make transmitter stick Also displayed digital read-out transmitter pulse width First would want mea sure incoming pulse length some reasons Standardizing equipment Lets say have new super transmitters mixing centering adjust ments end point adjustments exponential throw dual rates above Lets say after few months tweaking controls back transmitter things get pretty far out adjustment decide move system other plane may want set controls back factory specifications just have uniform starting point use computer measure cen ter end points transmitter chan nel readjusting channel well know certain have trans mitter adjustments back normal val ues can also quickly exacfly match two transmitters used buddy-box sys tem both instructor student have equal control throw Re-establishing settings between differ ent airplanes may have two planes operate same trans mitter need different throw centering adjustments can measure channel present setup accur ately make note measure ments can go back weeks months later re-establish same conditions determined optimum plane after transmitter has used other applications Checking stability over temperature An other use would check stability transmitter over range tempera tures perform temperature test charge up transmitter place freezer refrigerator few hours until its really cold simulates flying Min nesota January pull out freezer extend antenna fully turn Make note pulse length coming out channels Let transmitFigure 9 dont plan measure transmitter pulse length wont need make buffer amplifier circuit just test servos required solder female servo con nector directly computer plug setup can use menu options except #7 36 Model Aviation Figure 8 circuit everything hooked up except computer Never remove install connector power run risk blowing out something ter continue run coming up room temperature 20 30 minutes watch pulse length warms up Dont touch transmitter sticks during period See theres much difference between cold warm pulse length chan nel under test plan fly outside winter its good idea test entire system cold weather performance especially battery Some receivers servos have known fail cold temperatures brought equipment out warm car set up took off still warm might unpleasantly surprised something stops working no apparent re ason have observed least re ceiver quits working below 32 0F Checking stability over time check transmitter over time battery dis charges perform same test above freezing transmitter first Note pulse length transmitter first activated intervals battery runs down See theres differ encethis could explain some trim changes fly other benefits standardizing transmitter servo pulse widths manufacturers specifications exam ple transmitters set up same neutral pulse length can inter change servos receivers transmitters within systems being concerned about mixing matching equipment provided connectors mate op erating positive-pulse systems build transmitter kits repair transmitters pulse length measurement system can prove invaluable About circuit youll take look Figure #3 youll notice servo lead directly connected computer no interface just happens com puter CIA chip five-volt CMOS device generates pulses directly com patible standard RC servos No interfacing required drive servo di recfly computer arent interested measuring transmitter pulses dont need build rest circuitjust hook servo connector PC card edge connector plug computer Figure #9 Youll able use options software except Op tion #7 Measure Transmitter Pulse Length Although Commodore C-64 User Port output line has worked directly servos tested far Commodore User Port input line would work re ceivers Whether computer would work depended upon chip receiver using pulse decoder make computer work cases buf fer circuit designed condition coming signal receiver cir cuit consists two resistors PNP transistor provides gain isolation between test receiver computer buffer circuit place com puter has worked positive-pulse receiver have tested date About connector PC card edge connector labeled through 12 December 1988 37 Figure 10 pencil pointing two keys used prevent connector being installed upside down Theyre made piece plastic RC hinge mate rial CyAed place Make sure use installed properly Figure 11 find out accurately servo centers itself closely returns same end point install long pointer its output arm set up fixed pointer reference Mount servo steady position align fixed pointer the servo Se lect option #3 see closely servo returns its starting point cycles end Figure 12 Radio Shack IC experimenters board inexpensive yet rugged alternate hand-wired circuit could build circuit small box connect computer cable construction method described article simpler just reliable 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order Now fliers over world have neat inexpensive functional way protect R/C transmitters dlltr dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus Georgia 31904 404/323-2787 9am-5pm EST across top through N across bottom Notice letters G missing will fit computer either right side up upside down very careful insert properlyyou could dam age computer connecting upside down Look User Port back computer Youll see has two slots cut circuit board slots de signed mate two keys PC card edge connector responsible providing keys right location connector keys place its impossible insert connector wrong way See Figure #10 proper position ing two keysthey fit small slots between contacts con nector some reason keys arent normally supplied connector theyre almost impossible find lo cal radio store worry youll find some plastic RC hinge material cut size inserted connector care fully instant-glued place will serve ade quately other cautiondont ever plug PC card edge connector computer computer turned could get crosswise during process cause problem perhaps blowing computers internal fuse doing serious damage Building circuit circuit built 1Ath Radio Shack Experimenters Dual IC Board catalog number 276-159 see Figure #12 quarter section board cut off using Dremel tool soldered bottom row contacts PC card edge connector designed match Commodore User Port see Figure #2 edge connector has dual row con tacts 12 top 12 bottom isolated other obtained local electronics store GC Electronics part number 41-804 Amphenol part num ber 225-2-12-2-4-1-01 Cinch part num ber 251-12-30-160 use connector top bottom pins internally connected together could damage Commodore computer type con nector addition connector circuit board youll need 2N3638 PNP silicon transistor other general-purpose small signal PNP transistor specs arent critical 4700 Ohm resistor 22000 Ohm resis tor aileron extension matches radio system aileron exten sion Its convenient source male female connector have some other way coming up connectors thats OK Youll also need small amount solder wire usual small hand tools circuit board soldered directly edge connector pins per photograph Figure #2 Look carefully photo graph sure have pins connector aligned proper lands Continued page 40 38 Model Aviation 015 "~ si69 k\j wraar5a prarr r 5000r~ KVrS C0rlare- ceescrAl0 r0Od 55010 rr 500 Foaer5nOeIAflg O Iras earle is 4 fl Full Size AerObIG World Now Available n Thr 5ze MOdel Kits. TANDOF gCAL t4OUNClt4G OUR HN ANeed DeS gried Miles scale 6lpLAN 5h1 3000 5pAN A rs 15t s279~sr sier~ eOd P55 $154008 d Iuth Vas LaO e giLt Certd0rCerdrgeant Orders accelltedPersO V IANSCOVER Glow Plug Analyzers metered NI-STARTER McDaniel R/C analyzes condition glow plug time use start engine attached dualface ampmeter indicates good marginal failed plug Another innovation McDaniel R/C 1650 ma/hr recharge able battery provides 35% starting power regular nicads Dual-face ampmeter indicates plug condition attached Model 205 shown Model 201 w/charger Model 218 shown Model 217 w/charger Mode 204 020 wall stainless steel tube stainless steel spring direct connecting high temp teflon wiring beryllium copper electrode No sliding contacts corrode Positive 6-point PIgIaUCk will strip wear out 1IOV 220V AC chargers available other fine products fron McDaniel R/C see local hobby dealer contact McDaniel RIC Inc 12206 Guinevere Rd Glenn Dale MD 20769 301 464-2260 FAX 301 262-4433 Visa MC accepted take hassle out hobiry NI STARTER Palen nOV2001 & osoS ow Plug k Puen Pend NI-STOOTEOsaeo Ia0emarkof McD,nelOC Inc lO8O McDaniel RIC Inc circuit board Its easy off position clarity ease testing circuit board situated non-conven tional manner copper traces top board Should wish could build circuit small box ex tend wires computer found convenient con struction technique purposes Refer schematic diagram Figure #3 photographs guidance may need obtain assistance lo cal club electronics expert havent much experience reading schemat ics constructing electronic devices ware wiring errors could permanently damage computer especially care ful check everything twice before plug ging circuit User Port Once have parts mounted cut aileron extension half solder male female connectors circuit board per Figure #4 schematic drawing Check wiring once mis take could damage computer re quire replacement CIA chip C64 Power servo receiver taken directly Conanodore power sup ply Commodore literature says port can provide five volts up 250 mil liamperes accessory devices Some large servos will exceed current rating especially stalled cases must provide battery other separate source power servo inde pendent Commodore power supply per drawing Figure #5 could damage Commodore power supply draw excess 250 milliamperes port length time Hooking up measure incoming pulse length youll need receiver match transmitter under test Power re ceiver comes Commodore com puter supply should no problem providing required power receiv ers Ive tested have required less 50 mil liamperes current Youll have remove receiver model least un plug servo connectors battery connector receiver before start Power receiver comes back through servo lead its necessary connect switch haruess battery receiver could damage Com modore power supply leave re ceiver battery connected please remove connectors receiver before start During test youll have move leads connecting computer re ceiver servo socket channel receiver other its just easy pull receiver out model avoid fumbling inside tight quarters Once connections have made thoroughly checked plug servo servo connector plug receiver con nector channel want test Turn computer load software type LOAD PULSEMASTER8 type RUN program listing software would longer article describing sys tem Ill volunteer provide disk nominal fee cover cost disk mailer postage Its also available ready-to-use form CompuServe information near end article Operating software Once have software loaded running yopll see menu will give following options Figure #6 1 Slowly cycle servo 2 Rapidly cycle servo 3 Cycle end-center-end 4 Cycle 50 microsecond steps test ing linearity 5 Reset upper lower limits accom modate various systems 6 Set servo position 7 Measure transmitter pulse length 8 Slew servo 0 Quit select option simply enter num ber desired routine Now lets talk about what options Option #1 Slowly Cycle Servo op tion would selected servo suspected being erratic may have noticed example models control surface does smoothly follow motion transmitter stick Run routine carefully watch servo signs jitter see either jitter erratic operation likely its servo potentiometer motor fault Some servos have pots can cleaned others sealed must replaced Consult manufacturer have questions simply send suspicious servos back repairits worth cost new airplane should fail Option #2 Rapidly Cycle Servo option drives servo end its travel other Its used bura new servo few minutes see problems arise exercise servo thats sitting around unused test servo consistency using elon gated pointer connected output arm Dont overdo 30 seconds min ute should sufficient test just about servo Option #3 Cycle End-Center-End option useful want test reso lution centering servo Before option employed should use Option #5 Reset Upper Lower Limits RC system uses something other millisecond lower limit two mil liseconds upper limit Option #3 causes servo go end its normal travel other pausing momen tarily middle option becomes useful long pointer temporarily attached servo arm stationary reference pointer set up midpoint servo travel see Figure #1 1 can readily observe well servo centers have seen certain expensive coreless ser Continued page 111 40 Model Aviation Radio Technique/Myers Continued page 33 problems evident considered signif icant time comparison objec tive obtaining additional frequencies reference individuals quali fied perform tests transmitters receivers Will procedure approved FCC b will control supervise practic es persons c What packaging shipping methods used d What requirements placed upon people e Will labels placed upon transmit ters and/or receivers standardized receiver subjected major crash receiver may off frequency yet perform control placed upon previ ously accepted equipment Will AMA allow equipment assem bled repaired owner Will AMA re quire periodic tests transmitters receivers over years reference AMA Membership Man ual p 9 AMA Frequency Committee Recom mendations para 1 AMA will assume responsibility enforcement FCC regula tions will Clubs cannot afford test equipment FCC assuredly cannot pro vide enforcement other manufactur ing level good example Citizens Band ran wild very likely questions shall arise before afier implementa tion 1991 requirements What must remembered hobby participants average mod eler limited both funds time usually complies regulations imposed equipment becomes burden enjoy ment hobby will lost 1991 frequency requirements will force RC participants pay additional fees convert existing equipment buy new equipment appears trying obtain additional frequencies fliers contest field sport fliers paying right fly Myers comment AMA sought interference free frequencies replace shared frequen cies becoming unusable sport competition fliers alike due high-powered interference sharers exclusive new channels got rid high-powered sharers would appreciate presentation questions Frequency Committee re quest reply soon possible appreciation committees ef forts Myers comment copy Mr Kennedys let ter went Fred Marks FC chairman re ply went Mr Kennedy day letter received done expense Im paid AMA service nobody re imburses time materials reproduction cosrt stamp money either Pu Isemaster/Stuecker Continued page 40 vos dont seem center well some other less-expensive standard ser vos own tests see yourself servos want use Pat tern ship Option #4 Cycle SO Microsecond Steps option checks linearity servo over its entire operating range What linearity servo truly linear will move same number degrees time pulse length incremented 50 microseconds Most servos operate over one-millisecond range servo should move 20 equal-sized steps bottom limit top limit using option See Figure #1 graph ideal servo response Option #5 Reset Upper Lower Lim its software defaults standard range pulse lengths used Ace RC others millisecond 1000 mi croseconds lower limit two mil liseconds 2000 microseconds up per limit Futaba AM series however uses 81 milliseconds 181 milliseconds system limits 1310 millisec Continued page 141 December 1988 111 Editors note RC industry has begun offer RC equipment narrow band has certified independent testing laboratories FCC type acceptance meeting AMAs Guidelines 1991 oper ation Model Aviation its AMA News sec tion now regularly publishing lists such equipment first such list appeared October 1988 issue Thus ques tions being asked renders quoted George M Myers column being swered listing RMcM NEW ELECTRIC Fly Baby. great stand-way-off scale fun ship designed 05 electric power can perform take-offs touch goes aerobatics beauty yet enjoy docile slow flight easy landings Quick easy build kit includes pre cut fuselage sides tail feathers small parts hardware complete rolled plans step-by-step instructions formed landing gear windshield Electro-Combo includes kit DSC 075 Hyperthrust motor fused switch harness Tamiya connector propeller adaptor 8/4 fiberglass propeller 4 40 Span 275 Sq area 32 oz flying weight flat bottom airfoil rudder elevator motor add ailerons too HIAVEY SPECIAL COMBO PRICE $4795 YSTEMS 675 TO WER LANE BASIC KIT $24~4ORPoRATION 215-430-8645 Pu Isemaster/Stuecker Continued page 111 onds 1310 microseconds servo center Check literature system see what range pulse widths should use its other millisecond/two millisecond standard use option reset software match system re quirements Option #6 Set Servo Position option allows generate pulse known length length set num ber microseconds enter computer keyboard prevent damage servo caused excessive travel software limits range pulse widths between 500 microseconds 2500 microseconds gives error message try exceed limits servos will hit mechan ical stops certain pulse lengths within range should type pulse length greater servo can handle servo jams quickly unplug servo re type pulse length somewhere within working range servo before re connecting Deadband check want check servos deadband type number fol lowed RETURN will cause servo assume position near cen ter its travel 1500 should servos type another number slightly larger 1505 example see servo moves doesnt move youre still within servos deadband area Keep increasing number slighfly until notice servo jisst move can usually hear motor kick dif ference between last number first number typed servos deadband microseconds good servo will have tight deadband Repeat test few times Check manufacturers specs deadband see figures agree yours yours will accurate Resolution check check servos res olution secure servo stationary ob ject small vise handy tach long pointer straight piece music wire 8 10 long servos output arm Center servo above typing 1500 place stationary reference marker next end pointer Figure #11 Move servo arm other position typing 1700 exam ple type 1500 again per fect servo pointer would return exactly original position Most will off just littlethe better servo less will off Experiment few different ser vos see really better Weve found price isnt always good indica tion good resolution deadband per formance Option #7 Measure Transmitter Pulse Length option requires have receiver compatible transmitter plan test measure transmitter pulse length plug computer de sired channel receiver after discon necting other leads receiver cluding battery computer pro vides power receiver through _________________________T SERIES planes feature balsa construction Designed intermediate flyer in A-4 mind will accept 20-25 size engine luse rear exhaust angina axceptional Skyhawk performance Tha thrill jet hassles ducted fan *4000 &H Tha Proud Bird designed meet OSPRA Formula 120 rules ThIs 1/4 scale model will accept 60120 ci size engines Epoxy glees fuselage foam wing construction Full kit $150 Semi-kit also available mo wood Sia Please add 810 581 20 Tlgershark Send check MO MasterCard VISA add $3 lea add 6% esles tax Dart ExperImental two-place full sIze aircraft Top Turkey Formulal 506$55&H PARRISH AIRCRAFT 8 Scale Models ll25SW4SthTer Plantation FL 33317 December 1988 141 SPECIALISTS IN CUSTOM COX TEE DEE & REED ENGINES 020S 049 051S & 09S ALL CUSTOM & STOCK PARTS AVAILABLE INDIVIDUALLY MANY NEW PARTS FOR OLD DISCONTINUED COX ENGINES COX PROPS & GLOW HEADS COMPETITION ACCESSORIES & CUSTOMIZED K&B ENGINES ALSO COMPLETE LINE OF RACING PARTS - GLO-BEE FIREBALL & K&B PLUGS SOLID LINES RACING WHEELS QUICK FILLS ETC WE ALSO STOCK CARBON FIBER KLOTZ OIL LATEX & SILICONE FUEL TUBING PEN BLADDER MATERIALS & HARDTO-FIND HARDWARE ESPECIALLY 2-56 & 3-48 SIZES COILS CONDENSERS NGK & STITT PLUGS SILK 12 COLORS QUALITY DOPE BRUSHES 5 & 7 LOOP RUBBER BANDS KSB SEELIG & IGNITION TIMERS GAS & DIESEL FUEL TUBING TRANSISTOR IGNITION SYSTEMS RESISTOR HI-TENSION LEADS 1/2A TEXACO PLAYBOY SR KIT 1/2A TEXACO ENGINES & PARTS EVERYTHING YOU NEED FOR OLD TIMER EVENTS servo connector Turn transmitter select op tion will notice will hor izontal scale drawn computer screen calibrated milliseconds moving pointer follows motion transmitter stick see Figure #7 prefer digital read-out pulse length theres also numeric read out measuring incoming pulse length nearest microsecond option serves two purposes can used measure end points stick travel also can used see well transmit ter sticks return neutral after theyve released Let stick snap back neutral take reading slowly return stick neutral see get same reading Move stick opposite direction same good set sticks will typi cally return within few microseconds same neutral setting time either direction measurement solved problem originally thought servo linkage problem systems plane would stay trim problem finally found sticky stick transmitter didnt al ways return same spot after re leased word cautionif select Op tion #7 have receiver connected computer have receiver connected no transmitter running computer will appear lock up nor mal Whats happening computer waiting pulse come User Port get out locked-up mode hold down Run/Stop key tap Re store keys Option #8 Slew Servo allows slowly move servo through its range using arrow keys lower right side keyboard change servo output arm position moving output arm position using option given read-out near est microsecond pulse length servo receiving option can used check servo linearity have large pointer con nected servo output arm protrac tor other means accurately determin ing pointer position could plot curve pulse length horizontal axis servo rotation vertical axis servo truly linear curve plot will turn out perfectly straight line Figure #1 have about hours work $10 can build transmitter checker automated servo testing setup using handful parts inex pensive home computer dont hap pen have Commodore C-64 computer should someone within club does computerized radio/servo checker could make interesting group project something club could make available service during meet ing rainy weekend give mem bers means checking RC systems hope find useful tool Parts List 1 ea Aileron Connector match radio sys tem 1 ea PC Card Edge Connector match Com modore C64* IC Electromcs part #41-804 #41-816 Amphenol part #225-2-12-2-4-1-01 Cinch part #251-12-30-160 1 ea Experimenters Dual IC Board Radio Shack catalog #276-159 1 ea 2N3638 MPS2907 other PNP silicon general purpose small signal transistor Radio Shack catalog #276-2023 1 ea 4700 Ohm A-watt resistor Radio Shack catalog #271-1330 1 ca 22000 Ohm A-watt resistor Radio Shack Catalog #271-1339 Solder wire miscellaneous small hand tools *The cost PC card edge connector lo cal electronics dealer approximately $375 Its also listed part number 12/245E Jameco Electronics catalog costs $149 can reach Jameco Electronics 415 592-8097 write 1355 Shoreway Rd Belmont CA 94002 Janieco has $2000 minimum order may want get few friends together prepare bulk purchase Jameco also requires 5% handling fee $100 minimum Call Ja meco cant find connector locally have handful connectors Ill pro vide $500 first-come basis until supply runs out Please include pre-addressed stamped envelope orders case check has returned software project available Commodore diskette au thor CompuServe No hard copy printout available diskette can obtained sending $500 check money order cover cost disk mailer postage Bernard L Stuecker 2433 Carey Ln Vienna VA 22180 CompuServe subscribers can GO MOD ELNET find program software dowaloading Library 11 com mand BRO KEYSERVO can get CompuServe subscription information calling CompuServe 800 848-8199 AMA member would like free CompuServe subscription kit write Doug Pratt AMA HQ 1810 Samuel Morse Dr Reston VA 22090 ModelNet AMAs computer bulletin board service need information about project please sure include pre addressed stamped envelope query address above RC Soaring/Blakeslee Continued page 43 planes DG-100/428/132/229 DG-200 Acroracer/3 75/[ 106/ 128]/293 DG-200/ 428/119/257 DG-l00/428/143/250 DG 202/500/[139/16 11/216 first DG-100 now 11 years old wings DG-200 conventional con struction 2mm balsa sheeting steel blade joiners others have blue foam cores covered fiberglass obechi made using vacuum-bag technique DG-202 50 142 Model Aviation OUR REV-UP INVENTORY AVERAGES OVER 9000 PROPS I! CALL FOR IMMEDIATE SHIPMENT ON VISA OR MASTERCARD OLD TIMER SUPPLIES ORDER BY MAIL OR PHONE 619728-4365 SORRY NO COD VISA & MASTERCARD WELCOME DEALER INQUIRES INVITED MINIMUM MERCHANDISE ORDER $1000 SHIPPING & HANDLING FEE $150 E ADD $100 auinrn IAIITLJIId 2A UfI R5