Photon Servos two parts move against other destined wear out servos use translates feedback pot begins deterio rate time first moves have searched way avoid mechanical weak link now engineer own ranks may have come up photoelectric feedback system built around Dunham mechanics feedback pot housing has removed arrow points out light-dependent resistors ALMOST EVERY RC FLIER knows what feedback pot Some may have learned about hard way culprit behind crash best piloting skills couldnt have prevented causes trouble other part servo supposed necessary evils wed like able Its little carbon-coated vari able resistor servo has taken apart cleaned lubricated often maintenance isnt done servo arm will eventually become erratic jiggling jumping trying run continuously happens can generally kiss model good-bye feedback potentiometer used continuously-variable voltage divider fixed regulated voltage applied across pot wiper rotated servo motor through reduction gearing voltage divided continuously wiper moves its amplitude completely dependent upon position wiper therefore position output arm voltage governs duration reference pulse generated 36 Model Aviation 1 p-- answer EGeorge Gibson CuttheLDR retaining clipfromatin can lid use CyA glue LDRs place servo compared incoming control pulse receiver duration two pulses identical cancel out servo stops Any irregularity carbon surface pot element depending its character will cause malfunctions addition wiper slides over ele ment gradually wears away primarily over center travel tiny bits wiper metal depositedcausing element behave erratically evil weve put up ever since inception digital RC time Kraft Systems tried eliminate problems feedback pot putting variable capacitor refer ence pulse generator un provement system problems its own should know worked about 10000 Heathkit version servo As trend smaller smaller servos variable capacitors can made small approach phased out meantime quality pots increased price evident pots would always periodic maintenance nuisance Carbon button wiper contacts another im provement button popped out wiper arm saw happen re sulting problems could catastrophic late 1 960s John Cline F&M Electronics experimenting differ ent ways produce servo having incorporate feedback pot outcome research what called variable inductance servo see American Aircraft Modeler February 1968 relatively large metal-cased servo 1 1/16 x January 1987 37 Li Left scale drawing shows clip formed secure LDRs Note rim LDR recessed plastic case Right Remove feedback pot body Dremel tool knife Drill hole #2 screw cut notches wires look closely atthe arrow right can seethe LED peeking through shadow mask has cut hollow output shaft arrow left shows snugly clip holds LDRs Adjust shape clip until sure LDRs cannot move 1 x 3 available linear output eight-pin plug Chine stated research tried photoelectric feedback system before development light-emitting diodes LEDs photoelectrics necessarily de pended filament-type light bulb Cline recognized would im practical four counts mechanism would subject total failure warning whenever filament burned out would have little ability withstand typical model vibrations would cause ex cessive battery drain economically impractical Despite its drawbacks felt would work dont know variable inductance servo ever marketed never saw use photoelectric concept John Cline advanced just waiting technology make practical LEDs light-emitting diodes LDRs light-dependent resistors appeared commercial market couple years after went work Heathkit Co assignments evaluate pre-pro duction run Thumb Tac first photoelectric tachometer appear RC market used transistor-sized pho tocell aforementioned LDRs Thumb Tac developed engineer friend Heath successful both technically com mercially earned him advance grade both members Southwest Michigan Whirlwinds RC Club often discussed possibility using LDR Thumb Tac kit variable resistor reference pulse generator would eliminate trouble some wiping mechanical contacts conventional feedback pot prob lem foresaw LDRs have objectionable warm-up characteristic friend designed special IC chip com pensate LDR drift various reasons eventually dropped project Still idea stuck head decided try another approach keep simple Instead using single LDR requiring special IC retained regnlar Kraft IC used two LDRs series replace feedback pot LDRS carefully matched both would vary resistance same amount same direction During warm-up assuming equal illumination voltage junc tion would remain same junction point course would correspond wiper connection eliminated feed back pot make voltage vary such way simulate movement wiper feedback pot illuminating source would moved away neutral position throw light LDR other voltage junction would rise fall according resistor getting light viable choice light source LED Theyre small immune vibration have very economical current drain theres no filament burn out Almost John Clines problems solved simple device built couple servos using Kraft/ Heath mechanics made LED movable back forth between two LDRs proved concept would work making light source movable required either sliding contacts flexible leads knew inevitably would break cause catastrophic failure both light source light detector stationary moveable mask would have rigged between such way mask moved way other would partially cover uncover LDRs get same effect moving light source would eliminate sliding contacts flexing leads sitting just staring some servo parts constructive idea head suddenly great brainstorm blew through between ears chose servo output gear output shaft might have room gearbox underneath output gear shadow mask knew Dunhams R&R made servo #2 gear located over motor instead under output gear Kraft Heath did ordered four hadnt specified color received white proved problem allowed extraneous light leak onto LDRs tried painting cases black paint worked time flaked off easily Thereafter ordered black cases first successful shadow mask made anodized aluminum glued output shaft required two LEDs although would have increased current drain LEDs series could have simpler Another minor brainstorm resulted putting single LED inside output shaft carving hole side shaft illuminate LDRS As shaft rotated first LDR other would favored light would have effect similar moving light source insert LED bottom end hollow shaft remove short splined shaft attaches pot wiper As brass slug would dis carded along wiper needed devise another way center servo wanted make linearity travel centering adjustable least first few experimental versions O needed second circuit board carry three trimmer pots 50-cent type well some additional resistors capacitors Since no longer needed feedback pot way decided carve off down bottom case make room extra board its parts gave lots room electronics compartment built some ser vos two decks board above other parallel found difficult circuit testing replace parts regrouped ended up two boards mounted right angles mechanics electronics combined oriented shown fit inside servo case gear case cover put first travel adjustments done everything installed case layout has worked out OK far feel production two pots perhaps threecould eliminated single-board electronics would result Replacing troublesome failure-prone feedback pot wasnt simple hoped has definitely worth test-flew three-pot version described over period three years save linkage adjustment set main tenance-free Performance superior hadnt receiver failure causing fatal case fly-away-itis Id flying yet plan patent photon servo Im publicizing notion someone will develop further Adjustments both Kraft Heath servos feedback pot located collector reference pulse generator Its IC its still made up transis tors first substituted LDRs same position travel linearity good tried LDR double base circuit linearity still good Finally put diode base circuit reverse-biased would isolated except base driven neg ative cutoff pulse linearity 38 Model Aviation rough prototype set circuit boards shows perpendicular board layout electronics section vertical board Cir cuit Board #1 available Heathkit other constructed per text better could adjusted 10K pot connected across two LDRs wiper arm attached LDR junc tion Early project found LDR used Thumb Tac suitable servo use since high-resistance type contacted Clairol manufacturer found producing LDRS resistance ranges supplied performance data ordered 10 lowest-resistance range set up test jig Surprise resistance under identical test conditions varied much 300% batch 10 two nearly identical enough servo rest could matched up ordered another 100 got enough matches 29 servos dont have same value just have matched pairs Naturally choices available matches As no longer mechanical feedback pot need alternative method adjust servos centering replaced 1K load resistor collector circuit reference pulse generator inexpensive 2K pot small variation light intensity LDRs will result relatively large change voltage junctionmuch equivalent rotation feed back pot Resistors R2 R3 R4 form network attenuate voltage output arm can rotate farther before control voltage reaches value will result stop Resistor R2 also trimmer pot used adjust length servo travel some later versions mounted LDRs simply gluing place cyanoacrylate CyA units immediately began experience high fail ure rates though two earlier versions LDRs held untidily place wire clips still worked fine Out curiosity added CyA servos next day failed also assume CyA caused failures although dont know Mounting now done sheetmetal clips made top dog food can see pattern have no failures photon servo will draw current standard servo willbut sig nificantly neutral two LDRs will draw maximum about 3 mA LED about 5 mA comparison feedback pot draws 13 mA consider servos typically draw about 20 mA idle least 150 mA under load extra 4 mA insignificant over three years testing have never experienced battery-drain problems schematic parts marked * already installed original circuit board Heath part #238-95 will have make #2 circuit board simple have used three methods con struction Cut-and-peel copper foil very thin PC board material conventional etching non-foil perforated board using bent-over component leads interconnections As two PC boards will assembled 900 other board #2 must notched fit end several sizes 4-watt re sistors market sure get smallest size go -watt com ponents circuit draw enough current get warm trimmer pots used Digi-Key Corp enclosed sealed against dust As 6mm pots take up room #2 board resistors capacitor must carefully located interfere access diagrams should help avoid trouble Also since pots adjustable both top bottom can drill -in holes board pots can set non-component side should first attempt building servo youve successfully assembled kit servos should have little difficulty After boards Heath Some components will left off Heath board incorporated second others will change value type have Heath board already built up can use making necessary modifications Construction After trying servomechan isms several manufacturers decided Dunham D-1 particularly suited purpose has gear arrangement required plus hollow output shaft can modified use shadow-mask gears are of nylon filled Continued page 137 January1987 39 LORs non-polarized either end can connected B LEDs polarized will glow leads reversed Although shown fiat two boards will mounted right angles Note interconnections between two boards LED LDRs q1~ WEIGHT-MATES HEAVY DUTY FABRIC WEIGHT BAGS FOR BUILDING TRANSPORTING & FIELD TIE-DOWN Easily filled w/sand shot up 5 Ibs Five 4x6 bags per package Conforms curvatures Complete instructions $695 postage & handling AZ residents add 35X tas Radio Technique/Myers Continued page 133 transmitter receiver few AM FM sets already conform guidelines So can expect early part 1988 will see low band occupied some pretty good stuff will up keep way vigorously persuading rebels mend ways having equipment serviced periodically keep operating should Based transmitter tests performed three Nats three trade shows seems some AM FM transmitter designs can quali fied slight modifications same informa tion makes seem highly unlikely transmit ters now old channels BN/W through GN/W will ever qualified just basis costs involved Receivers another matter Very few exist ing receivers qualify except Kraft -8FD -8FDS dual-conversion PCM receivers like Simprop PCM-20 Multiplex time gets print expect other qualified receivers will put circula tion Ace R/C Airtronics Circus Futaba others will have own shopping leave reviewing business friend Bob Aberle does very well read Flying Models magazine dont already George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Photon Servos/Gibson Continued page 39 material glass fiber makes very sturdy Dunham guarantees free replace ment part fails reason including crash damage small lots sell approximately $7 lots 100 little over $2 Re member specify black cases order Disassemble servo com pletely careful lose parts particularly small gear pins output gear attached wiper rotor splined brass shaft extends 1GRATE-SHAPES SANDING BLOCKS GS 101 3/u XG5103 K G 5 105 &3k 90Vsw/% X GS 102 /o & m GS 0 %&wR Grit sides Always consistantly rounded edges Long-lasting silicon carbide grit Combo Package 101 102 & 103or specify three $1195 P & H AZ residents add 60 ta Single GRATE-SHAPES $495 P & H AZ residents add 255 tas products guaranteedDealers invited SEND cHECK OR---MONEY ORDER TO Bell Rock Industries Hwy 179-Suite 108 Sedona AZ 86336 284-1808 through bottom gear case Care fully pull upward gear will require some force will separate brass shaft will using shaft wiper project use method want separating damage bearing hole Unless old string saver discard shaft wiper feedback pot body molded integral part servo center section gear case bottom may split several segments can sawed off individually See Fig 4 use Moto Tool cutoff wheel carve stumps flush sharp knife Make two t/ie-in slots Moto cutoff tool drill hole clear #2 screw Now select red LED will fit bottom end output gear shaft LED should wide-angled should fit snugly turn freely flange LED must also sanded off allow inserted deep enough inside shaft Assemble output gear servo top section place LED leads extending down through bearing hole Pull LED down firmly grasping leads put droportwoof5-min epoxy bearing hole around leads use CyA anywhere else servo Let epoxy set firmly before proceeding further remove top section output gear retaining clip two LDRs made top tin can Spring brass bronze could also used dont recommend aluminum case must thin strong Dimensions details given Figs 2 & 3 LDRs will lay flat sides have rim prevents attempt grind flat spot rim though will destroy hermetic seal Instead use defunct metal-cased transis tor same size LED mount place retaining clip heat rim soldering iron until plastic melts E -% BOOSTER Space Age Charging Has Arnvedl Convenient solar charging will solve battery charging problems flying sight boosting batteries between flights Safe 100 MA Charge Rate Autumatic Cat-OS Full Charge High Efficiency Under Cloudy Cosditioou Charges-Both RX asd TX Simultaneously Popular Radio Systems Using 48 96 Volts Handy Plug-In Charging Cord Adjustable Angle Bracket Bailt Everyday Use RaggedLightweighl Easy Curry Handle Full Warranty $7995 Introductory Dtter $450 Shipping & Handling USA AZ Residents Add $400 Tax allows rim sink surface too much heat youll ruin plastic case recess melted case LDRs can now made set flat held place retaining clip Mount shown Fig 5 bending bottom lead LDR downward through Yt6-in slots other lead LDR will bent forward two joined can soldered retaining clip desired junction green wire board #2 will later soldered removing flange LED during its installation also removed flat flange identifies cathode lead install diode properly must re-identify lead connect two wires positive negative outputs flight battery solder 1000-ohm resistor end positive lead Touch negative wire LED lead free end 1K resistor other lead LED does light reverse connections LED lights lead going 1K resistor anode other lead cathode Bend cathode lead over flat solder lead LDR2 comes through slot Later black wire board #2 will connected also Now shadow mask Look bottom side output gear neutral point raised ridge about e-in wide radiating shaft out ward rim Take sharp point scribe line shaft center ridge downward bottom end shaft parallel its axis point line om end make tiny punch mark drill hole through shaft wall Enlarge hole /u6-in drill %2-in drill Dont drill through both sides shaft though Square up hole sharp X-Acto blade shadow mask complete January 1987 137 DGADelignsss OGA Designs DGA Designs. DGA Designs es DGA Designs o5 S *DARNED GOOD AIRMEN Lightest weight Pilots Available Ia0 * FULL BODY PILOT KIT e ke Vny e abbe pa-ts Easy assenble finish Kit contains Pilot head hands boots heintet5 Ocap goggles full tentplates easy inett-ttctiOns Fully positionable too0 Height- Weight-NEW LOW Pttces-5 NO206 .1/6 Scale lls 2 oz s72 rJ\rK NO206 5 Scale 14 3oz s89 No204-1/4 Scale 174 ozs 99501 V[7V kJO 203 13 Scale 236ozsI6 100 55PORT5MAN o BARNSTORMER- FULL RODS Oo RUSTfl/C C *s4J5 PILOT KIT LitSike 0OV lOthS 055t, pad,0 Ktt csntates PAst head hornet spod cap gossips OJacket. Easy asoornitie aho tjhsh Height WeightLOW Peicee5 ,No1O9t OScaip310Otoa5 59/5 4 No tOO t SRCOieO8tI 400sd%hc NO 04- aScaleadottao7Sh*sOme01 No tOg t iScale5-34240sl4~ simple tOsewtng5 Astounding htOliOeqt4irea0 4 attainable plastics.. ODoe tothete5temeti9et Weight Oat trntpiotcatoii ooa5o idiOt 0boOtS WiicaoeitttieothoettoctohthetaihctOtVootaiCatt 0 Send slOO Catalog SI Ne YOtt state RoOdoots add 75 sales tOO. Send Check ot- MO. cO Os Ai Oss 3 seeks cseck toctear 5 s DGA Designs 5 5 DGA 55 OGA Designs Reassembling gear train takes little sleight hand Put servo top section top cover separate Dunham D-l As top cover will remain place unassisted until case bottom can fastened wrap some tape around assembly retain cover no light can get Shorten remaining free lead CL-2 LATCH FOR COAL ItATCtI CAGtOPY & tdIttO AINPIN 2-STAGE PRESSURE STAG MORE GOODIES CANOPY TRACK AIRPIN PRESS GUAGE CUSTOM Ant CYLINDERS PROPHUT/SPINHER ATTACH EXT PROPEUTS FUR P-It PItU ete &IE OPERATES LATCH tTLAS Oev F2tGfltES STItoNGI ltD TIMER KITS SEND SASE FOR INFO DEALER INQUIRIES INVITED PHORE3O 73161 ROBINAIR E P 0 80X8770 CORAL SPRINGS FLORIDA33O75 MINICYLINDERS LED anode make soldering loop will later attach blue wire coming board #1 install motor point Rotate gears output gear neutral put output arm onto shaft neutral also Leave out arm retaining screw servo completed power should see bright red glow LED look down through top shaft Circuit board assembly As mentioned before circuit board #1 actually Heathkit part #238-95 using pre assembled board Heath servo leave following parts board power transistors motor leads servo con necting cable plug 1 0sF tantalum capacitor some units 22F 47F tantalum capacitor 001/LF ceramic capacitor IC Remove other parts Clip parts off above board try salvage Cut off flush top surface board will now very easy unsolder remaining stumps shake off board ruining foils process starting new board mount IC first being sure correctly oriented foil pad very narrow extends around three edges board 48-volt foil notched indented end IC will go middle section foil #1 pin will connect foil directly have provided diagram foil pattern copyrighted have identified holes use lettering top view board Fig 6 Assuming using red white black green color-coded servo connecting cable Heath has always used connect red wire hole marked B nearest pin #1 IC cases told connect wire component solder joint though another connection made later point system uses different color code youre own Connect black wire cable hole W also marked B- Connect green wire hole N nearest IC pin #12 cable has white wire clip plug strip out cable Use later needed Install two MPS6562 transistors leads marked transistor body EBC must go hole labeled corresponding letter see diagram sure leads short enough transistor does stand above board Install 47MF tantalum capacitor plus lead going hole T minus lead through hole U can use metal-cased type Heath used used dipped tantalum because fits better precision capacitor re quired Install OO1tF 1000 pF capacitor holes R S Heath used tubular unit used tiny disc capacitor Digi-Key just fits Again precision point required Install lOOK resistor RiO body standing up vertically hole X top lead bent over sharply enter hole Y 1 0MF 22FF dipped tantalum capacitor also destined holes X Y will installed later Install 82K resistor holes K L may necessary change value resistor depending servo operates place 22tF capacitor originally used holes F H install 1N914 diode F unbanded end down board left standing vertically later insertion #2 board Lay #1 board aside Prepare #2 board check shorts Borrow ohmmeter have set R x 1000 Touch meter lead foil pads touch other lead successively foil pad bordering first meter does deflect move another foil pad test its neighboring pads same man ner two foils produce indication short use X-Acto knife cut dividing lines deeper remove short sure absolutely no shorts between two foil pads proceed installation electronic components Install two 10K trimpots proper places non-foil side board should stand about %2-in high no Install R6 220K lies along left side board Position body resistor installed will act insulator against bare lead R3 Install two short bits bare wire holes opposite sides clearance notch end board Continued page 140 138 Model Aviation 45 m GEAR MECHANICS FOR BIGGIES Now Can Drill Grind Cut Sand Polish IN PLACES YOU NE VER COULD BEFORE FiRST TIME AVAILABLE great new precision tool has tough ABS housing hardened metal gears Iltetime lubricated bearings Attaches seconds Dremei Moto-Tool models #270 #280 #370 #380 Sears Craftsman rotary tools MUST FOR THE SMALL TOOL WORK SHOP R NOW AND SAVE Use thin onu~ send name addresn payment MICROUARKS Box 5112-3l3eCllnton NJ 08808 E Send n, 'a YES Send ______ RIGHT ANGLE DRIVES Item #50353 24-HOUR CREDIT CARD PI4ONEt 1400-225-1066 $1700 plus $200 shipphig andemtand dl am mm- lEt NJ 201-4644764 pletely satisfied may retum order en immediate refund NAME_______________________________ [ICheclr enclesed NJ residettla add 6% nolan tan [Charge [I VISA [I MaulerCard []AMEX ADDRESS___________________________________ Aoct#_____________________ [I Ship order C 00 $200 additionalCIlYSTATE______ ZIP ______ will connect #2 ground foil #1 ground B other will connect #2 22-volt B foil 22-volt pin IC Install R3 2200 ohms stand ver tically bend bare lead necessary go under R6 Install R4 2200 ohms flat board laid down Install R7 lOOK position shown Install C6 22tF dipped tantalum short negative lead board Leave positive lead long can connected board #1 later Cut 1-in length stranded orange wire Bare end twist strands together before soldering make insertion circuit board holes easier Connect end circuit foil board #2 shown Cut 2-in lengths blue black green orange wire prepare described previously 1-in stranded wire Connect blue wire top ofRi board #1 green black orange wires board #2 shown top Fig 5 Mount board #2 proper end board #1 components of#2 will overhang of# 1 short bits ofbare wire previously soldered lower end #2 should now bent downward fit vacant holes board #1 boards should form right angle notch board #2 should fit over end IC flush end Feed entire length positive lead 1 N9 14 diode through hole X board #2 Cover lead Teflon tubing bend over connect foil pad same place bare lead R7 connected Solder clip off excess lead Install lMF polyester capacitor Cl holes X andY lead goes through same hole used 1N914 diode Solder diode lead clip off excess wire leads must belong enough capacitor straddles top R3 Bend lead going through hole Y solder wiper terminal pot R8 Connect free end 1-in orange wire hole H shown Fig 6 other wires black green blue orange go LED-LDR photoelectric assembly gear case compartment Terminals assembly brought through gear case bottom feedback pot body removed Cut two pieces wire brown other white length 1 in, prepare ends before Put brown wire through hole M white wire through hole AZ Connect other ends wires motor follows white red positive terminal brown other terminal Connect CS 05F cer amic disc across motor terminals leads CS should left long enough extend down sides motor out way lead going red terminal must insulated other lead can left bare must grounded case Except connections photo electric assembly circuit board work now finished black wire connected junction LED LDR leads green wire junction LDRs orange wire remaining LDR lead blue wire anode re maining free end LED See ex planation Fig 5 motor removed pops right out gear train engaged plug servo receiver servooperator Turn power look down through top output shaft should see bright glow LED Though have built unit correctly will still almost certainly completely out adjustment Leave motor out gear box ie installed servo top section top cover place over gears photoelectric assembly Take off case bottom turn power motor should run transmitter off might initial twitch will run continuously until transmitter turned motor does begin run smoke LED does glow have defect construction Unplug servo look solder bridges misplaced parts other things electronics kits caution about unit OK far PRODUCTS FOR TIW n tmau Mf Unflet lete Line Exhaust Systems Tuned Pipes led Tuned Pipes Headers uri Mufflers Expansion Mufflers Helicopter Ball Mufflers ialized Exhaust Systems Unsurpassad Wnk,smnohin F Prftrmanc 140 Model Aviation New Robart RIGHT ANGLE DRIVE Dremel Moto-Tools U motor running turn transmitter motor will likely run direction unless struck lucky will stop reverse move control stick Shut receiver off adjust travel pot R2 extreme right its range looking top point maximum travel will reduce later procedure Make sure both transmitter receiver set servo arm neutral center adjust centering pot R8 point motor either stops oscillates Shut off receiver engage motor gear train Turn receiver back output arm runs side wont come back reverse leads motor start over correct motor connection may result servo arm oscillating though no command has given phenome non should cease travel pot readjusted now set travel pot mid-range arm comes rest point off-center set linearity pot R5 center positioning servo arm Now check 450 travel side center travel control affects total amount travel linearity control affects amount travel side center three controls centering linearity travel interact affects others may necessary go over several times Dont strive perfection making adjustments though because wont get finished servo oscillates IC may sensitive ones requires change 82Kresistor R9 value 68K 56K does oscillate fact seems underpowered change R9 either lOOK 120K changes will require small amount recentering given sudden large amounts stick action under no-load conditions servo will overshoot immediately re turn commanded position due lag response time LDRs confronted sudden large change brightness Since servos modeling environment rarely operate out some kind load would appear no problem Although further development servo might result eliminating two pots would seem 2K centering pot will always need retained can visualize though unit lower part output shaft shadow mask could independently adjustable respect output gear itself would friction adjustment could set top servo just servos now would require some delicate machining Im working Im also process trying adapt photoelectric concept use Signetics NE544 IC have little luck servo operates perfectly itself used other servos kind causes buzz jump oscillate Signetics chip does require additional external transistors does Kraft IC appeal smaller lighter still has experimenting have questions comments please write author George Gibson RR 1 Box 157 Fountain MI 49410 RC Soaring/Blakeslee Continued page 41 AMA did recognize Soaring time contest became bigger single AMA event premier event year event run Dan drew over 200 com petitors over country com petition its finest meet names like Mark Smith Dave Shadel Otto Heithecker Don Edberg Warren Plohr LeMon Payne Col Bob Thacker John Baxter Dave Thornburg Bob Gill Dale Nutter Jeff Mrlik Dwight Holly people flew against another single major contest today Glider pilots travel AMA Nats like did SOAR Nationals Dan Pruss ran class contest participation SOAR Nats reasons Soaring finally added AMA event Thank Dan Pruss will always treasure people experiences because Kurt Rosner fellow Rocky Mountain Soaring Association member favorite bird shot down off-field interference prompted Kurt try find Out what hit him So went out bought frequency scanner found commercial station operating 10 kHz below channel 44 First lets have Kurt describe scanner Regency MX500 may first readily-available new breed communica tions receivercontinuous coverage 25 550 MHz Other receivers give several seg ments bands within range dont give access example RC channels 72 MHz does frequency-synthesized no crystals keyboard-controlled alphanumeric LCD display comes nifty compact package can program 20-channel scanner set up search between two frequencies steps 5 125 25 kHz AM NFM WFM narrow- wide-band FM can selected example might want program up 20 RC channels Scan mode Search 720 730 MHz 5 kHz steps find potentially troublemaking signals lurking between RC channels area MX500 comes plug-in telescoping antenna 120-volt adapter cable install cigarette-lighter plug whatever cars 12-volt battery mounting bracket got CW Electronic Sales Denver $299 recently reduced $415 first hit market $600 Two nega tives instruction book skimpy doesnt cover keyboard-control capabilities unit Second little gem may distract real hobby Its imported Regency Electronics Inc 7707 Records St Indianapolis IN 46226 Kurts second step contact District IX Frequency Coordinator Steve Mangles lives Denver Steve found offender mobile phone service broadcasting data voice signals directionally Denver towards Boulder Kurt got hit Small consolation Kurt can hear signal loud clear new scanner Steve also learned same company L7ZY U L2 2U OOO LYUJLiI9 SEE OUR BACK COVER AD THIS ISSUE tested Maloney 100 first off quarter scale Cap 20L thai weighed about 15 pounds model first flown 23 cdee rich Zenoah G-23 Frar*ly Maloney 100 would get model trp air could loop level flight model under powered moat people standards Robinhood 80s 12 1/2 ounds fly wel i ntly bulit 90 sized Long John again shortened nose came 10 1/2 pounds model complete flaps fiAt symmetrIcal airfoil model seemingly will maneuver asked flaps down lands about Smiles per hour hope builders smaller Long John will get produce thla sIze kit Weve Modeltech develop two airplanes around Maloney 100 engine Jose StIk Dragon Lady Both modele fly great kept light designed Export 7 ch aystem w14 servos Maloney 100 Robinhood SO Modeltech Dragonlady Modeltech Joss Silk except outsIde loop J 10 1/2 pounds Robinhood will outslde loop very well cut nose back Robinhood 80 put firewal about 1 inch windshleld meets fuselage Notce cowied engine photo model uses small servos still fling 1200mAh battery peck fother reason thanspendalotof out Presently retaling Expert 7 channel system four servos NiCads transmitter flight packs charger neck strap frequency flag $33995 moment might lid retailers -both hobby mail order shops sefling thle system low $15000 terrific buy compared what get some ether systems br kind money fear prIce system will probably going si little bit near future because continuing devaluation US Blail $33995 $19995 $8995 $22495 $15995 j2ZJ u IQ GOQ G2ThLD 8960 Rossash Ave Cincinnati Ohio 45236 Phone 513 793-5900 x 214 557 January 1987 141 JeJtatmtlId maximize performance Maloney 100
Edition: Model Aviation - 1987/01
Page Numbers: 36, 37, 38, 39, 137, 138, 140, 141
Photon Servos two parts move against other destined wear out servos use translates feedback pot begins deterio rate time first moves have searched way avoid mechanical weak link now engineer own ranks may have come up photoelectric feedback system built around Dunham mechanics feedback pot housing has removed arrow points out light-dependent resistors ALMOST EVERY RC FLIER knows what feedback pot Some may have learned about hard way culprit behind crash best piloting skills couldnt have prevented causes trouble other part servo supposed necessary evils wed like able Its little carbon-coated vari able resistor servo has taken apart cleaned lubricated often maintenance isnt done servo arm will eventually become erratic jiggling jumping trying run continuously happens can generally kiss model good-bye feedback potentiometer used continuously-variable voltage divider fixed regulated voltage applied across pot wiper rotated servo motor through reduction gearing voltage divided continuously wiper moves its amplitude completely dependent upon position wiper therefore position output arm voltage governs duration reference pulse generated 36 Model Aviation 1 p-- answer EGeorge Gibson CuttheLDR retaining clipfromatin can lid use CyA glue LDRs place servo compared incoming control pulse receiver duration two pulses identical cancel out servo stops Any irregularity carbon surface pot element depending its character will cause malfunctions addition wiper slides over ele ment gradually wears away primarily over center travel tiny bits wiper metal depositedcausing element behave erratically evil weve put up ever since inception digital RC time Kraft Systems tried eliminate problems feedback pot putting variable capacitor refer ence pulse generator un provement system problems its own should know worked about 10000 Heathkit version servo As trend smaller smaller servos variable capacitors can made small approach phased out meantime quality pots increased price evident pots would always periodic maintenance nuisance Carbon button wiper contacts another im provement button popped out wiper arm saw happen re sulting problems could catastrophic late 1 960s John Cline F&M Electronics experimenting differ ent ways produce servo having incorporate feedback pot outcome research what called variable inductance servo see American Aircraft Modeler February 1968 relatively large metal-cased servo 1 1/16 x January 1987 37 Li Left scale drawing shows clip formed secure LDRs Note rim LDR recessed plastic case Right Remove feedback pot body Dremel tool knife Drill hole #2 screw cut notches wires look closely atthe arrow right can seethe LED peeking through shadow mask has cut hollow output shaft arrow left shows snugly clip holds LDRs Adjust shape clip until sure LDRs cannot move 1 x 3 available linear output eight-pin plug Chine stated research tried photoelectric feedback system before development light-emitting diodes LEDs photoelectrics necessarily de pended filament-type light bulb Cline recognized would im practical four counts mechanism would subject total failure warning whenever filament burned out would have little ability withstand typical model vibrations would cause ex cessive battery drain economically impractical Despite its drawbacks felt would work dont know variable inductance servo ever marketed never saw use photoelectric concept John Cline advanced just waiting technology make practical LEDs light-emitting diodes LDRs light-dependent resistors appeared commercial market couple years after went work Heathkit Co assignments evaluate pre-pro duction run Thumb Tac first photoelectric tachometer appear RC market used transistor-sized pho tocell aforementioned LDRs Thumb Tac developed engineer friend Heath successful both technically com mercially earned him advance grade both members Southwest Michigan Whirlwinds RC Club often discussed possibility using LDR Thumb Tac kit variable resistor reference pulse generator would eliminate trouble some wiping mechanical contacts conventional feedback pot prob lem foresaw LDRs have objectionable warm-up characteristic friend designed special IC chip com pensate LDR drift various reasons eventually dropped project Still idea stuck head decided try another approach keep simple Instead using single LDR requiring special IC retained regnlar Kraft IC used two LDRs series replace feedback pot LDRS carefully matched both would vary resistance same amount same direction During warm-up assuming equal illumination voltage junc tion would remain same junction point course would correspond wiper connection eliminated feed back pot make voltage vary such way simulate movement wiper feedback pot illuminating source would moved away neutral position throw light LDR other voltage junction would rise fall according resistor getting light viable choice light source LED Theyre small immune vibration have very economical current drain theres no filament burn out Almost John Clines problems solved simple device built couple servos using Kraft/ Heath mechanics made LED movable back forth between two LDRs proved concept would work making light source movable required either sliding contacts flexible leads knew inevitably would break cause catastrophic failure both light source light detector stationary moveable mask would have rigged between such way mask moved way other would partially cover uncover LDRs get same effect moving light source would eliminate sliding contacts flexing leads sitting just staring some servo parts constructive idea head suddenly great brainstorm blew through between ears chose servo output gear output shaft might have room gearbox underneath output gear shadow mask knew Dunhams R&R made servo #2 gear located over motor instead under output gear Kraft Heath did ordered four hadnt specified color received white proved problem allowed extraneous light leak onto LDRs tried painting cases black paint worked time flaked off easily Thereafter ordered black cases first successful shadow mask made anodized aluminum glued output shaft required two LEDs although would have increased current drain LEDs series could have simpler Another minor brainstorm resulted putting single LED inside output shaft carving hole side shaft illuminate LDRS As shaft rotated first LDR other would favored light would have effect similar moving light source insert LED bottom end hollow shaft remove short splined shaft attaches pot wiper As brass slug would dis carded along wiper needed devise another way center servo wanted make linearity travel centering adjustable least first few experimental versions O needed second circuit board carry three trimmer pots 50-cent type well some additional resistors capacitors Since no longer needed feedback pot way decided carve off down bottom case make room extra board its parts gave lots room electronics compartment built some ser vos two decks board above other parallel found difficult circuit testing replace parts regrouped ended up two boards mounted right angles mechanics electronics combined oriented shown fit inside servo case gear case cover put first travel adjustments done everything installed case layout has worked out OK far feel production two pots perhaps threecould eliminated single-board electronics would result Replacing troublesome failure-prone feedback pot wasnt simple hoped has definitely worth test-flew three-pot version described over period three years save linkage adjustment set main tenance-free Performance superior hadnt receiver failure causing fatal case fly-away-itis Id flying yet plan patent photon servo Im publicizing notion someone will develop further Adjustments both Kraft Heath servos feedback pot located collector reference pulse generator Its IC its still made up transis tors first substituted LDRs same position travel linearity good tried LDR double base circuit linearity still good Finally put diode base circuit reverse-biased would isolated except base driven neg ative cutoff pulse linearity 38 Model Aviation rough prototype set circuit boards shows perpendicular board layout electronics section vertical board Cir cuit Board #1 available Heathkit other constructed per text better could adjusted 10K pot connected across two LDRs wiper arm attached LDR junc tion Early project found LDR used Thumb Tac suitable servo use since high-resistance type contacted Clairol manufacturer found producing LDRS resistance ranges supplied performance data ordered 10 lowest-resistance range set up test jig Surprise resistance under identical test conditions varied much 300% batch 10 two nearly identical enough servo rest could matched up ordered another 100 got enough matches 29 servos dont have same value just have matched pairs Naturally choices available matches As no longer mechanical feedback pot need alternative method adjust servos centering replaced 1K load resistor collector circuit reference pulse generator inexpensive 2K pot small variation light intensity LDRs will result relatively large change voltage junctionmuch equivalent rotation feed back pot Resistors R2 R3 R4 form network attenuate voltage output arm can rotate farther before control voltage reaches value will result stop Resistor R2 also trimmer pot used adjust length servo travel some later versions mounted LDRs simply gluing place cyanoacrylate CyA units immediately began experience high fail ure rates though two earlier versions LDRs held untidily place wire clips still worked fine Out curiosity added CyA servos next day failed also assume CyA caused failures although dont know Mounting now done sheetmetal clips made top dog food can see pattern have no failures photon servo will draw current standard servo willbut sig nificantly neutral two LDRs will draw maximum about 3 mA LED about 5 mA comparison feedback pot draws 13 mA consider servos typically draw about 20 mA idle least 150 mA under load extra 4 mA insignificant over three years testing have never experienced battery-drain problems schematic parts marked * already installed original circuit board Heath part #238-95 will have make #2 circuit board simple have used three methods con struction Cut-and-peel copper foil very thin PC board material conventional etching non-foil perforated board using bent-over component leads interconnections As two PC boards will assembled 900 other board #2 must notched fit end several sizes 4-watt re sistors market sure get smallest size go -watt com ponents circuit draw enough current get warm trimmer pots used Digi-Key Corp enclosed sealed against dust As 6mm pots take up room #2 board resistors capacitor must carefully located interfere access diagrams should help avoid trouble Also since pots adjustable both top bottom can drill -in holes board pots can set non-component side should first attempt building servo youve successfully assembled kit servos should have little difficulty After boards Heath Some components will left off Heath board incorporated second others will change value type have Heath board already built up can use making necessary modifications Construction After trying servomechan isms several manufacturers decided Dunham D-1 particularly suited purpose has gear arrangement required plus hollow output shaft can modified use shadow-mask gears are of nylon filled Continued page 137 January1987 39 LORs non-polarized either end can connected B LEDs polarized will glow leads reversed Although shown fiat two boards will mounted right angles Note interconnections between two boards LED LDRs q1~ WEIGHT-MATES HEAVY DUTY FABRIC WEIGHT BAGS FOR BUILDING TRANSPORTING & FIELD TIE-DOWN Easily filled w/sand shot up 5 Ibs Five 4x6 bags per package Conforms curvatures Complete instructions $695 postage & handling AZ residents add 35X tas Radio Technique/Myers Continued page 133 transmitter receiver few AM FM sets already conform guidelines So can expect early part 1988 will see low band occupied some pretty good stuff will up keep way vigorously persuading rebels mend ways having equipment serviced periodically keep operating should Based transmitter tests performed three Nats three trade shows seems some AM FM transmitter designs can quali fied slight modifications same informa tion makes seem highly unlikely transmit ters now old channels BN/W through GN/W will ever qualified just basis costs involved Receivers another matter Very few exist ing receivers qualify except Kraft -8FD -8FDS dual-conversion PCM receivers like Simprop PCM-20 Multiplex time gets print expect other qualified receivers will put circula tion Ace R/C Airtronics Circus Futaba others will have own shopping leave reviewing business friend Bob Aberle does very well read Flying Models magazine dont already George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Photon Servos/Gibson Continued page 39 material glass fiber makes very sturdy Dunham guarantees free replace ment part fails reason including crash damage small lots sell approximately $7 lots 100 little over $2 Re member specify black cases order Disassemble servo com pletely careful lose parts particularly small gear pins output gear attached wiper rotor splined brass shaft extends 1GRATE-SHAPES SANDING BLOCKS GS 101 3/u XG5103 K G 5 105 &3k 90Vsw/% X GS 102 /o & m GS 0 %&wR Grit sides Always consistantly rounded edges Long-lasting silicon carbide grit Combo Package 101 102 & 103or specify three $1195 P & H AZ residents add 60 ta Single GRATE-SHAPES $495 P & H AZ residents add 255 tas products guaranteedDealers invited SEND cHECK OR---MONEY ORDER TO Bell Rock Industries Hwy 179-Suite 108 Sedona AZ 86336 284-1808 through bottom gear case Care fully pull upward gear will require some force will separate brass shaft will using shaft wiper project use method want separating damage bearing hole Unless old string saver discard shaft wiper feedback pot body molded integral part servo center section gear case bottom may split several segments can sawed off individually See Fig 4 use Moto Tool cutoff wheel carve stumps flush sharp knife Make two t/ie-in slots Moto cutoff tool drill hole clear #2 screw Now select red LED will fit bottom end output gear shaft LED should wide-angled should fit snugly turn freely flange LED must also sanded off allow inserted deep enough inside shaft Assemble output gear servo top section place LED leads extending down through bearing hole Pull LED down firmly grasping leads put droportwoof5-min epoxy bearing hole around leads use CyA anywhere else servo Let epoxy set firmly before proceeding further remove top section output gear retaining clip two LDRs made top tin can Spring brass bronze could also used dont recommend aluminum case must thin strong Dimensions details given Figs 2 & 3 LDRs will lay flat sides have rim prevents attempt grind flat spot rim though will destroy hermetic seal Instead use defunct metal-cased transis tor same size LED mount place retaining clip heat rim soldering iron until plastic melts E -% BOOSTER Space Age Charging Has Arnvedl Convenient solar charging will solve battery charging problems flying sight boosting batteries between flights Safe 100 MA Charge Rate Autumatic Cat-OS Full Charge High Efficiency Under Cloudy Cosditioou Charges-Both RX asd TX Simultaneously Popular Radio Systems Using 48 96 Volts Handy Plug-In Charging Cord Adjustable Angle Bracket Bailt Everyday Use RaggedLightweighl Easy Curry Handle Full Warranty $7995 Introductory Dtter $450 Shipping & Handling USA AZ Residents Add $400 Tax allows rim sink surface too much heat youll ruin plastic case recess melted case LDRs can now made set flat held place retaining clip Mount shown Fig 5 bending bottom lead LDR downward through Yt6-in slots other lead LDR will bent forward two joined can soldered retaining clip desired junction green wire board #2 will later soldered removing flange LED during its installation also removed flat flange identifies cathode lead install diode properly must re-identify lead connect two wires positive negative outputs flight battery solder 1000-ohm resistor end positive lead Touch negative wire LED lead free end 1K resistor other lead LED does light reverse connections LED lights lead going 1K resistor anode other lead cathode Bend cathode lead over flat solder lead LDR2 comes through slot Later black wire board #2 will connected also Now shadow mask Look bottom side output gear neutral point raised ridge about e-in wide radiating shaft out ward rim Take sharp point scribe line shaft center ridge downward bottom end shaft parallel its axis point line om end make tiny punch mark drill hole through shaft wall Enlarge hole /u6-in drill %2-in drill Dont drill through both sides shaft though Square up hole sharp X-Acto blade shadow mask complete January 1987 137 DGADelignsss OGA Designs DGA Designs. DGA Designs es DGA Designs o5 S *DARNED GOOD AIRMEN Lightest weight Pilots Available Ia0 * FULL BODY PILOT KIT e ke Vny e abbe pa-ts Easy assenble finish Kit contains Pilot head hands boots heintet5 Ocap goggles full tentplates easy inett-ttctiOns Fully positionable too0 Height- Weight-NEW LOW Pttces-5 NO206 .1/6 Scale lls 2 oz s72 rJ\rK NO206 5 Scale 14 3oz s89 No204-1/4 Scale 174 ozs 99501 V[7V kJO 203 13 Scale 236ozsI6 100 55PORT5MAN o BARNSTORMER- FULL RODS Oo RUSTfl/C C *s4J5 PILOT KIT LitSike 0OV lOthS 055t, pad,0 Ktt csntates PAst head hornet spod cap gossips OJacket. Easy asoornitie aho tjhsh Height WeightLOW Peicee5 ,No1O9t OScaip310Otoa5 59/5 4 No tOO t SRCOieO8tI 400sd%hc NO 04- aScaleadottao7Sh*sOme01 No tOg t iScale5-34240sl4~ simple tOsewtng5 Astounding htOliOeqt4irea0 4 attainable plastics.. ODoe tothete5temeti9et Weight Oat trntpiotcatoii ooa5o idiOt 0boOtS WiicaoeitttieothoettoctohthetaihctOtVootaiCatt 0 Send slOO Catalog SI Ne YOtt state RoOdoots add 75 sales tOO. Send Check ot- MO. cO Os Ai Oss 3 seeks cseck toctear 5 s DGA Designs 5 5 DGA 55 OGA Designs Reassembling gear train takes little sleight hand Put servo top section top cover separate Dunham D-l As top cover will remain place unassisted until case bottom can fastened wrap some tape around assembly retain cover no light can get Shorten remaining free lead CL-2 LATCH FOR COAL ItATCtI CAGtOPY & tdIttO AINPIN 2-STAGE PRESSURE STAG MORE GOODIES CANOPY TRACK AIRPIN PRESS GUAGE CUSTOM Ant CYLINDERS PROPHUT/SPINHER ATTACH EXT PROPEUTS FUR P-It PItU ete &IE OPERATES LATCH tTLAS Oev F2tGfltES STItoNGI ltD TIMER KITS SEND SASE FOR INFO DEALER INQUIRIES INVITED PHORE3O 73161 ROBINAIR E P 0 80X8770 CORAL SPRINGS FLORIDA33O75 MINICYLINDERS LED anode make soldering loop will later attach blue wire coming board #1 install motor point Rotate gears output gear neutral put output arm onto shaft neutral also Leave out arm retaining screw servo completed power should see bright red glow LED look down through top shaft Circuit board assembly As mentioned before circuit board #1 actually Heathkit part #238-95 using pre assembled board Heath servo leave following parts board power transistors motor leads servo con necting cable plug 1 0sF tantalum capacitor some units 22F 47F tantalum capacitor 001/LF ceramic capacitor IC Remove other parts Clip parts off above board try salvage Cut off flush top surface board will now very easy unsolder remaining stumps shake off board ruining foils process starting new board mount IC first being sure correctly oriented foil pad very narrow extends around three edges board 48-volt foil notched indented end IC will go middle section foil #1 pin will connect foil directly have provided diagram foil pattern copyrighted have identified holes use lettering top view board Fig 6 Assuming using red white black green color-coded servo connecting cable Heath has always used connect red wire hole marked B nearest pin #1 IC cases told connect wire component solder joint though another connection made later point system uses different color code youre own Connect black wire cable hole W also marked B- Connect green wire hole N nearest IC pin #12 cable has white wire clip plug strip out cable Use later needed Install two MPS6562 transistors leads marked transistor body EBC must go hole labeled corresponding letter see diagram sure leads short enough transistor does stand above board Install 47MF tantalum capacitor plus lead going hole T minus lead through hole U can use metal-cased type Heath used used dipped tantalum because fits better precision capacitor re quired Install OO1tF 1000 pF capacitor holes R S Heath used tubular unit used tiny disc capacitor Digi-Key just fits Again precision point required Install lOOK resistor RiO body standing up vertically hole X top lead bent over sharply enter hole Y 1 0MF 22FF dipped tantalum capacitor also destined holes X Y will installed later Install 82K resistor holes K L may necessary change value resistor depending servo operates place 22tF capacitor originally used holes F H install 1N914 diode F unbanded end down board left standing vertically later insertion #2 board Lay #1 board aside Prepare #2 board check shorts Borrow ohmmeter have set R x 1000 Touch meter lead foil pads touch other lead successively foil pad bordering first meter does deflect move another foil pad test its neighboring pads same man ner two foils produce indication short use X-Acto knife cut dividing lines deeper remove short sure absolutely no shorts between two foil pads proceed installation electronic components Install two 10K trimpots proper places non-foil side board should stand about %2-in high no Install R6 220K lies along left side board Position body resistor installed will act insulator against bare lead R3 Install two short bits bare wire holes opposite sides clearance notch end board Continued page 140 138 Model Aviation 45 m GEAR MECHANICS FOR BIGGIES Now Can Drill Grind Cut Sand Polish IN PLACES YOU NE VER COULD BEFORE FiRST TIME AVAILABLE great new precision tool has tough ABS housing hardened metal gears Iltetime lubricated bearings Attaches seconds Dremei Moto-Tool models #270 #280 #370 #380 Sears Craftsman rotary tools MUST FOR THE SMALL TOOL WORK SHOP R NOW AND SAVE Use thin onu~ send name addresn payment MICROUARKS Box 5112-3l3eCllnton NJ 08808 E Send n, 'a YES Send ______ RIGHT ANGLE DRIVES Item #50353 24-HOUR CREDIT CARD PI4ONEt 1400-225-1066 $1700 plus $200 shipphig andemtand dl am mm- lEt NJ 201-4644764 pletely satisfied may retum order en immediate refund NAME_______________________________ [ICheclr enclesed NJ residettla add 6% nolan tan [Charge [I VISA [I MaulerCard []AMEX ADDRESS___________________________________ Aoct#_____________________ [I Ship order C 00 $200 additionalCIlYSTATE______ ZIP ______ will connect #2 ground foil #1 ground B other will connect #2 22-volt B foil 22-volt pin IC Install R3 2200 ohms stand ver tically bend bare lead necessary go under R6 Install R4 2200 ohms flat board laid down Install R7 lOOK position shown Install C6 22tF dipped tantalum short negative lead board Leave positive lead long can connected board #1 later Cut 1-in length stranded orange wire Bare end twist strands together before soldering make insertion circuit board holes easier Connect end circuit foil board #2 shown Cut 2-in lengths blue black green orange wire prepare described previously 1-in stranded wire Connect blue wire top ofRi board #1 green black orange wires board #2 shown top Fig 5 Mount board #2 proper end board #1 components of#2 will overhang of# 1 short bits ofbare wire previously soldered lower end #2 should now bent downward fit vacant holes board #1 boards should form right angle notch board #2 should fit over end IC flush end Feed entire length positive lead 1 N9 14 diode through hole X board #2 Cover lead Teflon tubing bend over connect foil pad same place bare lead R7 connected Solder clip off excess lead Install lMF polyester capacitor Cl holes X andY lead goes through same hole used 1N914 diode Solder diode lead clip off excess wire leads must belong enough capacitor straddles top R3 Bend lead going through hole Y solder wiper terminal pot R8 Connect free end 1-in orange wire hole H shown Fig 6 other wires black green blue orange go LED-LDR photoelectric assembly gear case compartment Terminals assembly brought through gear case bottom feedback pot body removed Cut two pieces wire brown other white length 1 in, prepare ends before Put brown wire through hole M white wire through hole AZ Connect other ends wires motor follows white red positive terminal brown other terminal Connect CS 05F cer amic disc across motor terminals leads CS should left long enough extend down sides motor out way lead going red terminal must insulated other lead can left bare must grounded case Except connections photo electric assembly circuit board work now finished black wire connected junction LED LDR leads green wire junction LDRs orange wire remaining LDR lead blue wire anode re maining free end LED See ex planation Fig 5 motor removed pops right out gear train engaged plug servo receiver servooperator Turn power look down through top output shaft should see bright glow LED Though have built unit correctly will still almost certainly completely out adjustment Leave motor out gear box ie installed servo top section top cover place over gears photoelectric assembly Take off case bottom turn power motor should run transmitter off might initial twitch will run continuously until transmitter turned motor does begin run smoke LED does glow have defect construction Unplug servo look solder bridges misplaced parts other things electronics kits caution about unit OK far PRODUCTS FOR TIW n tmau Mf Unflet lete Line Exhaust Systems Tuned Pipes led Tuned Pipes Headers uri Mufflers Expansion Mufflers Helicopter Ball Mufflers ialized Exhaust Systems Unsurpassad Wnk,smnohin F Prftrmanc 140 Model Aviation New Robart RIGHT ANGLE DRIVE Dremel Moto-Tools U motor running turn transmitter motor will likely run direction unless struck lucky will stop reverse move control stick Shut receiver off adjust travel pot R2 extreme right its range looking top point maximum travel will reduce later procedure Make sure both transmitter receiver set servo arm neutral center adjust centering pot R8 point motor either stops oscillates Shut off receiver engage motor gear train Turn receiver back output arm runs side wont come back reverse leads motor start over correct motor connection may result servo arm oscillating though no command has given phenome non should cease travel pot readjusted now set travel pot mid-range arm comes rest point off-center set linearity pot R5 center positioning servo arm Now check 450 travel side center travel control affects total amount travel linearity control affects amount travel side center three controls centering linearity travel interact affects others may necessary go over several times Dont strive perfection making adjustments though because wont get finished servo oscillates IC may sensitive ones requires change 82Kresistor R9 value 68K 56K does oscillate fact seems underpowered change R9 either lOOK 120K changes will require small amount recentering given sudden large amounts stick action under no-load conditions servo will overshoot immediately re turn commanded position due lag response time LDRs confronted sudden large change brightness Since servos modeling environment rarely operate out some kind load would appear no problem Although further development servo might result eliminating two pots would seem 2K centering pot will always need retained can visualize though unit lower part output shaft shadow mask could independently adjustable respect output gear itself would friction adjustment could set top servo just servos now would require some delicate machining Im working Im also process trying adapt photoelectric concept use Signetics NE544 IC have little luck servo operates perfectly itself used other servos kind causes buzz jump oscillate Signetics chip does require additional external transistors does Kraft IC appeal smaller lighter still has experimenting have questions comments please write author George Gibson RR 1 Box 157 Fountain MI 49410 RC Soaring/Blakeslee Continued page 41 AMA did recognize Soaring time contest became bigger single AMA event premier event year event run Dan drew over 200 com petitors over country com petition its finest meet names like Mark Smith Dave Shadel Otto Heithecker Don Edberg Warren Plohr LeMon Payne Col Bob Thacker John Baxter Dave Thornburg Bob Gill Dale Nutter Jeff Mrlik Dwight Holly people flew against another single major contest today Glider pilots travel AMA Nats like did SOAR Nationals Dan Pruss ran class contest participation SOAR Nats reasons Soaring finally added AMA event Thank Dan Pruss will always treasure people experiences because Kurt Rosner fellow Rocky Mountain Soaring Association member favorite bird shot down off-field interference prompted Kurt try find Out what hit him So went out bought frequency scanner found commercial station operating 10 kHz below channel 44 First lets have Kurt describe scanner Regency MX500 may first readily-available new breed communica tions receivercontinuous coverage 25 550 MHz Other receivers give several seg ments bands within range dont give access example RC channels 72 MHz does frequency-synthesized no crystals keyboard-controlled alphanumeric LCD display comes nifty compact package can program 20-channel scanner set up search between two frequencies steps 5 125 25 kHz AM NFM WFM narrow- wide-band FM can selected example might want program up 20 RC channels Scan mode Search 720 730 MHz 5 kHz steps find potentially troublemaking signals lurking between RC channels area MX500 comes plug-in telescoping antenna 120-volt adapter cable install cigarette-lighter plug whatever cars 12-volt battery mounting bracket got CW Electronic Sales Denver $299 recently reduced $415 first hit market $600 Two nega tives instruction book skimpy doesnt cover keyboard-control capabilities unit Second little gem may distract real hobby Its imported Regency Electronics Inc 7707 Records St Indianapolis IN 46226 Kurts second step contact District IX Frequency Coordinator Steve Mangles lives Denver Steve found offender mobile phone service broadcasting data voice signals directionally Denver towards Boulder Kurt got hit Small consolation Kurt can hear signal loud clear new scanner Steve also learned same company L7ZY U L2 2U OOO LYUJLiI9 SEE OUR BACK COVER AD THIS ISSUE tested Maloney 100 first off quarter scale Cap 20L thai weighed about 15 pounds model first flown 23 cdee rich Zenoah G-23 Frar*ly Maloney 100 would get model trp air could loop level flight model under powered moat people standards Robinhood 80s 12 1/2 ounds fly wel i ntly bulit 90 sized Long John again shortened nose came 10 1/2 pounds model complete flaps fiAt symmetrIcal airfoil model seemingly will maneuver asked flaps down lands about Smiles per hour hope builders smaller Long John will get produce thla sIze kit Weve Modeltech develop two airplanes around Maloney 100 engine Jose StIk Dragon Lady Both modele fly great kept light designed Export 7 ch aystem w14 servos Maloney 100 Robinhood SO Modeltech Dragonlady Modeltech Joss Silk except outsIde loop J 10 1/2 pounds Robinhood will outslde loop very well cut nose back Robinhood 80 put firewal about 1 inch windshleld meets fuselage Notce cowied engine photo model uses small servos still fling 1200mAh battery peck fother reason thanspendalotof out Presently retaling Expert 7 channel system four servos NiCads transmitter flight packs charger neck strap frequency flag $33995 moment might lid retailers -both hobby mail order shops sefling thle system low $15000 terrific buy compared what get some ether systems br kind money fear prIce system will probably going si little bit near future because continuing devaluation US Blail $33995 $19995 $8995 $22495 $15995 j2ZJ u IQ GOQ G2ThLD 8960 Rossash Ave Cincinnati Ohio 45236 Phone 513 793-5900 x 214 557 January 1987 141 JeJtatmtlId maximize performance Maloney 100
Edition: Model Aviation - 1987/01
Page Numbers: 36, 37, 38, 39, 137, 138, 140, 141
Photon Servos two parts move against other destined wear out servos use translates feedback pot begins deterio rate time first moves have searched way avoid mechanical weak link now engineer own ranks may have come up photoelectric feedback system built around Dunham mechanics feedback pot housing has removed arrow points out light-dependent resistors ALMOST EVERY RC FLIER knows what feedback pot Some may have learned about hard way culprit behind crash best piloting skills couldnt have prevented causes trouble other part servo supposed necessary evils wed like able Its little carbon-coated vari able resistor servo has taken apart cleaned lubricated often maintenance isnt done servo arm will eventually become erratic jiggling jumping trying run continuously happens can generally kiss model good-bye feedback potentiometer used continuously-variable voltage divider fixed regulated voltage applied across pot wiper rotated servo motor through reduction gearing voltage divided continuously wiper moves its amplitude completely dependent upon position wiper therefore position output arm voltage governs duration reference pulse generated 36 Model Aviation 1 p-- answer EGeorge Gibson CuttheLDR retaining clipfromatin can lid use CyA glue LDRs place servo compared incoming control pulse receiver duration two pulses identical cancel out servo stops Any irregularity carbon surface pot element depending its character will cause malfunctions addition wiper slides over ele ment gradually wears away primarily over center travel tiny bits wiper metal depositedcausing element behave erratically evil weve put up ever since inception digital RC time Kraft Systems tried eliminate problems feedback pot putting variable capacitor refer ence pulse generator un provement system problems its own should know worked about 10000 Heathkit version servo As trend smaller smaller servos variable capacitors can made small approach phased out meantime quality pots increased price evident pots would always periodic maintenance nuisance Carbon button wiper contacts another im provement button popped out wiper arm saw happen re sulting problems could catastrophic late 1 960s John Cline F&M Electronics experimenting differ ent ways produce servo having incorporate feedback pot outcome research what called variable inductance servo see American Aircraft Modeler February 1968 relatively large metal-cased servo 1 1/16 x January 1987 37 Li Left scale drawing shows clip formed secure LDRs Note rim LDR recessed plastic case Right Remove feedback pot body Dremel tool knife Drill hole #2 screw cut notches wires look closely atthe arrow right can seethe LED peeking through shadow mask has cut hollow output shaft arrow left shows snugly clip holds LDRs Adjust shape clip until sure LDRs cannot move 1 x 3 available linear output eight-pin plug Chine stated research tried photoelectric feedback system before development light-emitting diodes LEDs photoelectrics necessarily de pended filament-type light bulb Cline recognized would im practical four counts mechanism would subject total failure warning whenever filament burned out would have little ability withstand typical model vibrations would cause ex cessive battery drain economically impractical Despite its drawbacks felt would work dont know variable inductance servo ever marketed never saw use photoelectric concept John Cline advanced just waiting technology make practical LEDs light-emitting diodes LDRs light-dependent resistors appeared commercial market couple years after went work Heathkit Co assignments evaluate pre-pro duction run Thumb Tac first photoelectric tachometer appear RC market used transistor-sized pho tocell aforementioned LDRs Thumb Tac developed engineer friend Heath successful both technically com mercially earned him advance grade both members Southwest Michigan Whirlwinds RC Club often discussed possibility using LDR Thumb Tac kit variable resistor reference pulse generator would eliminate trouble some wiping mechanical contacts conventional feedback pot prob lem foresaw LDRs have objectionable warm-up characteristic friend designed special IC chip com pensate LDR drift various reasons eventually dropped project Still idea stuck head decided try another approach keep simple Instead using single LDR requiring special IC retained regnlar Kraft IC used two LDRs series replace feedback pot LDRS carefully matched both would vary resistance same amount same direction During warm-up assuming equal illumination voltage junc tion would remain same junction point course would correspond wiper connection eliminated feed back pot make voltage vary such way simulate movement wiper feedback pot illuminating source would moved away neutral position throw light LDR other voltage junction would rise fall according resistor getting light viable choice light source LED Theyre small immune vibration have very economical current drain theres no filament burn out Almost John Clines problems solved simple device built couple servos using Kraft/ Heath mechanics made LED movable back forth between two LDRs proved concept would work making light source movable required either sliding contacts flexible leads knew inevitably would break cause catastrophic failure both light source light detector stationary moveable mask would have rigged between such way mask moved way other would partially cover uncover LDRs get same effect moving light source would eliminate sliding contacts flexing leads sitting just staring some servo parts constructive idea head suddenly great brainstorm blew through between ears chose servo output gear output shaft might have room gearbox underneath output gear shadow mask knew Dunhams R&R made servo #2 gear located over motor instead under output gear Kraft Heath did ordered four hadnt specified color received white proved problem allowed extraneous light leak onto LDRs tried painting cases black paint worked time flaked off easily Thereafter ordered black cases first successful shadow mask made anodized aluminum glued output shaft required two LEDs although would have increased current drain LEDs series could have simpler Another minor brainstorm resulted putting single LED inside output shaft carving hole side shaft illuminate LDRS As shaft rotated first LDR other would favored light would have effect similar moving light source insert LED bottom end hollow shaft remove short splined shaft attaches pot wiper As brass slug would dis carded along wiper needed devise another way center servo wanted make linearity travel centering adjustable least first few experimental versions O needed second circuit board carry three trimmer pots 50-cent type well some additional resistors capacitors Since no longer needed feedback pot way decided carve off down bottom case make room extra board its parts gave lots room electronics compartment built some ser vos two decks board above other parallel found difficult circuit testing replace parts regrouped ended up two boards mounted right angles mechanics electronics combined oriented shown fit inside servo case gear case cover put first travel adjustments done everything installed case layout has worked out OK far feel production two pots perhaps threecould eliminated single-board electronics would result Replacing troublesome failure-prone feedback pot wasnt simple hoped has definitely worth test-flew three-pot version described over period three years save linkage adjustment set main tenance-free Performance superior hadnt receiver failure causing fatal case fly-away-itis Id flying yet plan patent photon servo Im publicizing notion someone will develop further Adjustments both Kraft Heath servos feedback pot located collector reference pulse generator Its IC its still made up transis tors first substituted LDRs same position travel linearity good tried LDR double base circuit linearity still good Finally put diode base circuit reverse-biased would isolated except base driven neg ative cutoff pulse linearity 38 Model Aviation rough prototype set circuit boards shows perpendicular board layout electronics section vertical board Cir cuit Board #1 available Heathkit other constructed per text better could adjusted 10K pot connected across two LDRs wiper arm attached LDR junc tion Early project found LDR used Thumb Tac suitable servo use since high-resistance type contacted Clairol manufacturer found producing LDRS resistance ranges supplied performance data ordered 10 lowest-resistance range set up test jig Surprise resistance under identical test conditions varied much 300% batch 10 two nearly identical enough servo rest could matched up ordered another 100 got enough matches 29 servos dont have same value just have matched pairs Naturally choices available matches As no longer mechanical feedback pot need alternative method adjust servos centering replaced 1K load resistor collector circuit reference pulse generator inexpensive 2K pot small variation light intensity LDRs will result relatively large change voltage junctionmuch equivalent rotation feed back pot Resistors R2 R3 R4 form network attenuate voltage output arm can rotate farther before control voltage reaches value will result stop Resistor R2 also trimmer pot used adjust length servo travel some later versions mounted LDRs simply gluing place cyanoacrylate CyA units immediately began experience high fail ure rates though two earlier versions LDRs held untidily place wire clips still worked fine Out curiosity added CyA servos next day failed also assume CyA caused failures although dont know Mounting now done sheetmetal clips made top dog food can see pattern have no failures photon servo will draw current standard servo willbut sig nificantly neutral two LDRs will draw maximum about 3 mA LED about 5 mA comparison feedback pot draws 13 mA consider servos typically draw about 20 mA idle least 150 mA under load extra 4 mA insignificant over three years testing have never experienced battery-drain problems schematic parts marked * already installed original circuit board Heath part #238-95 will have make #2 circuit board simple have used three methods con struction Cut-and-peel copper foil very thin PC board material conventional etching non-foil perforated board using bent-over component leads interconnections As two PC boards will assembled 900 other board #2 must notched fit end several sizes 4-watt re sistors market sure get smallest size go -watt com ponents circuit draw enough current get warm trimmer pots used Digi-Key Corp enclosed sealed against dust As 6mm pots take up room #2 board resistors capacitor must carefully located interfere access diagrams should help avoid trouble Also since pots adjustable both top bottom can drill -in holes board pots can set non-component side should first attempt building servo youve successfully assembled kit servos should have little difficulty After boards Heath Some components will left off Heath board incorporated second others will change value type have Heath board already built up can use making necessary modifications Construction After trying servomechan isms several manufacturers decided Dunham D-1 particularly suited purpose has gear arrangement required plus hollow output shaft can modified use shadow-mask gears are of nylon filled Continued page 137 January1987 39 LORs non-polarized either end can connected B LEDs polarized will glow leads reversed Although shown fiat two boards will mounted right angles Note interconnections between two boards LED LDRs q1~ WEIGHT-MATES HEAVY DUTY FABRIC WEIGHT BAGS FOR BUILDING TRANSPORTING & FIELD TIE-DOWN Easily filled w/sand shot up 5 Ibs Five 4x6 bags per package Conforms curvatures Complete instructions $695 postage & handling AZ residents add 35X tas Radio Technique/Myers Continued page 133 transmitter receiver few AM FM sets already conform guidelines So can expect early part 1988 will see low band occupied some pretty good stuff will up keep way vigorously persuading rebels mend ways having equipment serviced periodically keep operating should Based transmitter tests performed three Nats three trade shows seems some AM FM transmitter designs can quali fied slight modifications same informa tion makes seem highly unlikely transmit ters now old channels BN/W through GN/W will ever qualified just basis costs involved Receivers another matter Very few exist ing receivers qualify except Kraft -8FD -8FDS dual-conversion PCM receivers like Simprop PCM-20 Multiplex time gets print expect other qualified receivers will put circula tion Ace R/C Airtronics Circus Futaba others will have own shopping leave reviewing business friend Bob Aberle does very well read Flying Models magazine dont already George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Photon Servos/Gibson Continued page 39 material glass fiber makes very sturdy Dunham guarantees free replace ment part fails reason including crash damage small lots sell approximately $7 lots 100 little over $2 Re member specify black cases order Disassemble servo com pletely careful lose parts particularly small gear pins output gear attached wiper rotor splined brass shaft extends 1GRATE-SHAPES SANDING BLOCKS GS 101 3/u XG5103 K G 5 105 &3k 90Vsw/% X GS 102 /o & m GS 0 %&wR Grit sides Always consistantly rounded edges Long-lasting silicon carbide grit Combo Package 101 102 & 103or specify three $1195 P & H AZ residents add 60 ta Single GRATE-SHAPES $495 P & H AZ residents add 255 tas products guaranteedDealers invited SEND cHECK OR---MONEY ORDER TO Bell Rock Industries Hwy 179-Suite 108 Sedona AZ 86336 284-1808 through bottom gear case Care fully pull upward gear will require some force will separate brass shaft will using shaft wiper project use method want separating damage bearing hole Unless old string saver discard shaft wiper feedback pot body molded integral part servo center section gear case bottom may split several segments can sawed off individually See Fig 4 use Moto Tool cutoff wheel carve stumps flush sharp knife Make two t/ie-in slots Moto cutoff tool drill hole clear #2 screw Now select red LED will fit bottom end output gear shaft LED should wide-angled should fit snugly turn freely flange LED must also sanded off allow inserted deep enough inside shaft Assemble output gear servo top section place LED leads extending down through bearing hole Pull LED down firmly grasping leads put droportwoof5-min epoxy bearing hole around leads use CyA anywhere else servo Let epoxy set firmly before proceeding further remove top section output gear retaining clip two LDRs made top tin can Spring brass bronze could also used dont recommend aluminum case must thin strong Dimensions details given Figs 2 & 3 LDRs will lay flat sides have rim prevents attempt grind flat spot rim though will destroy hermetic seal Instead use defunct metal-cased transis tor same size LED mount place retaining clip heat rim soldering iron until plastic melts E -% BOOSTER Space Age Charging Has Arnvedl Convenient solar charging will solve battery charging problems flying sight boosting batteries between flights Safe 100 MA Charge Rate Autumatic Cat-OS Full Charge High Efficiency Under Cloudy Cosditioou Charges-Both RX asd TX Simultaneously Popular Radio Systems Using 48 96 Volts Handy Plug-In Charging Cord Adjustable Angle Bracket Bailt Everyday Use RaggedLightweighl Easy Curry Handle Full Warranty $7995 Introductory Dtter $450 Shipping & Handling USA AZ Residents Add $400 Tax allows rim sink surface too much heat youll ruin plastic case recess melted case LDRs can now made set flat held place retaining clip Mount shown Fig 5 bending bottom lead LDR downward through Yt6-in slots other lead LDR will bent forward two joined can soldered retaining clip desired junction green wire board #2 will later soldered removing flange LED during its installation also removed flat flange identifies cathode lead install diode properly must re-identify lead connect two wires positive negative outputs flight battery solder 1000-ohm resistor end positive lead Touch negative wire LED lead free end 1K resistor other lead LED does light reverse connections LED lights lead going 1K resistor anode other lead cathode Bend cathode lead over flat solder lead LDR2 comes through slot Later black wire board #2 will connected also Now shadow mask Look bottom side output gear neutral point raised ridge about e-in wide radiating shaft out ward rim Take sharp point scribe line shaft center ridge downward bottom end shaft parallel its axis point line om end make tiny punch mark drill hole through shaft wall Enlarge hole /u6-in drill %2-in drill Dont drill through both sides shaft though Square up hole sharp X-Acto blade shadow mask complete January 1987 137 DGADelignsss OGA Designs DGA Designs. DGA Designs es DGA Designs o5 S *DARNED GOOD AIRMEN Lightest weight Pilots Available Ia0 * FULL BODY PILOT KIT e ke Vny e abbe pa-ts Easy assenble finish Kit contains Pilot head hands boots heintet5 Ocap goggles full tentplates easy inett-ttctiOns Fully positionable too0 Height- Weight-NEW LOW Pttces-5 NO206 .1/6 Scale lls 2 oz s72 rJ\rK NO206 5 Scale 14 3oz s89 No204-1/4 Scale 174 ozs 99501 V[7V kJO 203 13 Scale 236ozsI6 100 55PORT5MAN o BARNSTORMER- FULL RODS Oo RUSTfl/C C *s4J5 PILOT KIT LitSike 0OV lOthS 055t, pad,0 Ktt csntates PAst head hornet spod cap gossips OJacket. Easy asoornitie aho tjhsh Height WeightLOW Peicee5 ,No1O9t OScaip310Otoa5 59/5 4 No tOO t SRCOieO8tI 400sd%hc NO 04- aScaleadottao7Sh*sOme01 No tOg t iScale5-34240sl4~ simple tOsewtng5 Astounding htOliOeqt4irea0 4 attainable plastics.. ODoe tothete5temeti9et Weight Oat trntpiotcatoii ooa5o idiOt 0boOtS WiicaoeitttieothoettoctohthetaihctOtVootaiCatt 0 Send slOO Catalog SI Ne YOtt state RoOdoots add 75 sales tOO. Send Check ot- MO. cO Os Ai Oss 3 seeks cseck toctear 5 s DGA Designs 5 5 DGA 55 OGA Designs Reassembling gear train takes little sleight hand Put servo top section top cover separate Dunham D-l As top cover will remain place unassisted until case bottom can fastened wrap some tape around assembly retain cover no light can get Shorten remaining free lead CL-2 LATCH FOR COAL ItATCtI CAGtOPY & tdIttO AINPIN 2-STAGE PRESSURE STAG MORE GOODIES CANOPY TRACK AIRPIN PRESS GUAGE CUSTOM Ant CYLINDERS PROPHUT/SPINHER ATTACH EXT PROPEUTS FUR P-It PItU ete &IE OPERATES LATCH tTLAS Oev F2tGfltES STItoNGI ltD TIMER KITS SEND SASE FOR INFO DEALER INQUIRIES INVITED PHORE3O 73161 ROBINAIR E P 0 80X8770 CORAL SPRINGS FLORIDA33O75 MINICYLINDERS LED anode make soldering loop will later attach blue wire coming board #1 install motor point Rotate gears output gear neutral put output arm onto shaft neutral also Leave out arm retaining screw servo completed power should see bright red glow LED look down through top shaft Circuit board assembly As mentioned before circuit board #1 actually Heathkit part #238-95 using pre assembled board Heath servo leave following parts board power transistors motor leads servo con necting cable plug 1 0sF tantalum capacitor some units 22F 47F tantalum capacitor 001/LF ceramic capacitor IC Remove other parts Clip parts off above board try salvage Cut off flush top surface board will now very easy unsolder remaining stumps shake off board ruining foils process starting new board mount IC first being sure correctly oriented foil pad very narrow extends around three edges board 48-volt foil notched indented end IC will go middle section foil #1 pin will connect foil directly have provided diagram foil pattern copyrighted have identified holes use lettering top view board Fig 6 Assuming using red white black green color-coded servo connecting cable Heath has always used connect red wire hole marked B nearest pin #1 IC cases told connect wire component solder joint though another connection made later point system uses different color code youre own Connect black wire cable hole W also marked B- Connect green wire hole N nearest IC pin #12 cable has white wire clip plug strip out cable Use later needed Install two MPS6562 transistors leads marked transistor body EBC must go hole labeled corresponding letter see diagram sure leads short enough transistor does stand above board Install 47MF tantalum capacitor plus lead going hole T minus lead through hole U can use metal-cased type Heath used used dipped tantalum because fits better precision capacitor re quired Install OO1tF 1000 pF capacitor holes R S Heath used tubular unit used tiny disc capacitor Digi-Key just fits Again precision point required Install lOOK resistor RiO body standing up vertically hole X top lead bent over sharply enter hole Y 1 0MF 22FF dipped tantalum capacitor also destined holes X Y will installed later Install 82K resistor holes K L may necessary change value resistor depending servo operates place 22tF capacitor originally used holes F H install 1N914 diode F unbanded end down board left standing vertically later insertion #2 board Lay #1 board aside Prepare #2 board check shorts Borrow ohmmeter have set R x 1000 Touch meter lead foil pads touch other lead successively foil pad bordering first meter does deflect move another foil pad test its neighboring pads same man ner two foils produce indication short use X-Acto knife cut dividing lines deeper remove short sure absolutely no shorts between two foil pads proceed installation electronic components Install two 10K trimpots proper places non-foil side board should stand about %2-in high no Install R6 220K lies along left side board Position body resistor installed will act insulator against bare lead R3 Install two short bits bare wire holes opposite sides clearance notch end board Continued page 140 138 Model Aviation 45 m GEAR MECHANICS FOR BIGGIES Now Can Drill Grind Cut Sand Polish IN PLACES YOU NE VER COULD BEFORE FiRST TIME AVAILABLE great new precision tool has tough ABS housing hardened metal gears Iltetime lubricated bearings Attaches seconds Dremei Moto-Tool models #270 #280 #370 #380 Sears Craftsman rotary tools MUST FOR THE SMALL TOOL WORK SHOP R NOW AND SAVE Use thin onu~ send name addresn payment MICROUARKS Box 5112-3l3eCllnton NJ 08808 E Send n, 'a YES Send ______ RIGHT ANGLE DRIVES Item #50353 24-HOUR CREDIT CARD PI4ONEt 1400-225-1066 $1700 plus $200 shipphig andemtand dl am mm- lEt NJ 201-4644764 pletely satisfied may retum order en immediate refund NAME_______________________________ [ICheclr enclesed NJ residettla add 6% nolan tan [Charge [I VISA [I MaulerCard []AMEX ADDRESS___________________________________ Aoct#_____________________ [I Ship order C 00 $200 additionalCIlYSTATE______ ZIP ______ will connect #2 ground foil #1 ground B other will connect #2 22-volt B foil 22-volt pin IC Install R3 2200 ohms stand ver tically bend bare lead necessary go under R6 Install R4 2200 ohms flat board laid down Install R7 lOOK position shown Install C6 22tF dipped tantalum short negative lead board Leave positive lead long can connected board #1 later Cut 1-in length stranded orange wire Bare end twist strands together before soldering make insertion circuit board holes easier Connect end circuit foil board #2 shown Cut 2-in lengths blue black green orange wire prepare described previously 1-in stranded wire Connect blue wire top ofRi board #1 green black orange wires board #2 shown top Fig 5 Mount board #2 proper end board #1 components of#2 will overhang of# 1 short bits ofbare wire previously soldered lower end #2 should now bent downward fit vacant holes board #1 boards should form right angle notch board #2 should fit over end IC flush end Feed entire length positive lead 1 N9 14 diode through hole X board #2 Cover lead Teflon tubing bend over connect foil pad same place bare lead R7 connected Solder clip off excess lead Install lMF polyester capacitor Cl holes X andY lead goes through same hole used 1N914 diode Solder diode lead clip off excess wire leads must belong enough capacitor straddles top R3 Bend lead going through hole Y solder wiper terminal pot R8 Connect free end 1-in orange wire hole H shown Fig 6 other wires black green blue orange go LED-LDR photoelectric assembly gear case compartment Terminals assembly brought through gear case bottom feedback pot body removed Cut two pieces wire brown other white length 1 in, prepare ends before Put brown wire through hole M white wire through hole AZ Connect other ends wires motor follows white red positive terminal brown other terminal Connect CS 05F cer amic disc across motor terminals leads CS should left long enough extend down sides motor out way lead going red terminal must insulated other lead can left bare must grounded case Except connections photo electric assembly circuit board work now finished black wire connected junction LED LDR leads green wire junction LDRs orange wire remaining LDR lead blue wire anode re maining free end LED See ex planation Fig 5 motor removed pops right out gear train engaged plug servo receiver servooperator Turn power look down through top output shaft should see bright glow LED Though have built unit correctly will still almost certainly completely out adjustment Leave motor out gear box ie installed servo top section top cover place over gears photoelectric assembly Take off case bottom turn power motor should run transmitter off might initial twitch will run continuously until transmitter turned motor does begin run smoke LED does glow have defect construction Unplug servo look solder bridges misplaced parts other things electronics kits caution about unit OK far PRODUCTS FOR TIW n tmau Mf Unflet lete Line Exhaust Systems Tuned Pipes led Tuned Pipes Headers uri Mufflers Expansion Mufflers Helicopter Ball Mufflers ialized Exhaust Systems Unsurpassad Wnk,smnohin F Prftrmanc 140 Model Aviation New Robart RIGHT ANGLE DRIVE Dremel Moto-Tools U motor running turn transmitter motor will likely run direction unless struck lucky will stop reverse move control stick Shut receiver off adjust travel pot R2 extreme right its range looking top point maximum travel will reduce later procedure Make sure both transmitter receiver set servo arm neutral center adjust centering pot R8 point motor either stops oscillates Shut off receiver engage motor gear train Turn receiver back output arm runs side wont come back reverse leads motor start over correct motor connection may result servo arm oscillating though no command has given phenome non should cease travel pot readjusted now set travel pot mid-range arm comes rest point off-center set linearity pot R5 center positioning servo arm Now check 450 travel side center travel control affects total amount travel linearity control affects amount travel side center three controls centering linearity travel interact affects others may necessary go over several times Dont strive perfection making adjustments though because wont get finished servo oscillates IC may sensitive ones requires change 82Kresistor R9 value 68K 56K does oscillate fact seems underpowered change R9 either lOOK 120K changes will require small amount recentering given sudden large amounts stick action under no-load conditions servo will overshoot immediately re turn commanded position due lag response time LDRs confronted sudden large change brightness Since servos modeling environment rarely operate out some kind load would appear no problem Although further development servo might result eliminating two pots would seem 2K centering pot will always need retained can visualize though unit lower part output shaft shadow mask could independently adjustable respect output gear itself would friction adjustment could set top servo just servos now would require some delicate machining Im working Im also process trying adapt photoelectric concept use Signetics NE544 IC have little luck servo operates perfectly itself used other servos kind causes buzz jump oscillate Signetics chip does require additional external transistors does Kraft IC appeal smaller lighter still has experimenting have questions comments please write author George Gibson RR 1 Box 157 Fountain MI 49410 RC Soaring/Blakeslee Continued page 41 AMA did recognize Soaring time contest became bigger single AMA event premier event year event run Dan drew over 200 com petitors over country com petition its finest meet names like Mark Smith Dave Shadel Otto Heithecker Don Edberg Warren Plohr LeMon Payne Col Bob Thacker John Baxter Dave Thornburg Bob Gill Dale Nutter Jeff Mrlik Dwight Holly people flew against another single major contest today Glider pilots travel AMA Nats like did SOAR Nationals Dan Pruss ran class contest participation SOAR Nats reasons Soaring finally added AMA event Thank Dan Pruss will always treasure people experiences because Kurt Rosner fellow Rocky Mountain Soaring Association member favorite bird shot down off-field interference prompted Kurt try find Out what hit him So went out bought frequency scanner found commercial station operating 10 kHz below channel 44 First lets have Kurt describe scanner Regency MX500 may first readily-available new breed communica tions receivercontinuous coverage 25 550 MHz Other receivers give several seg ments bands within range dont give access example RC channels 72 MHz does frequency-synthesized no crystals keyboard-controlled alphanumeric LCD display comes nifty compact package can program 20-channel scanner set up search between two frequencies steps 5 125 25 kHz AM NFM WFM narrow- wide-band FM can selected example might want program up 20 RC channels Scan mode Search 720 730 MHz 5 kHz steps find potentially troublemaking signals lurking between RC channels area MX500 comes plug-in telescoping antenna 120-volt adapter cable install cigarette-lighter plug whatever cars 12-volt battery mounting bracket got CW Electronic Sales Denver $299 recently reduced $415 first hit market $600 Two nega tives instruction book skimpy doesnt cover keyboard-control capabilities unit Second little gem may distract real hobby Its imported Regency Electronics Inc 7707 Records St Indianapolis IN 46226 Kurts second step contact District IX Frequency Coordinator Steve Mangles lives Denver Steve found offender mobile phone service broadcasting data voice signals directionally Denver towards Boulder Kurt got hit Small consolation Kurt can hear signal loud clear new scanner Steve also learned same company L7ZY U L2 2U OOO LYUJLiI9 SEE OUR BACK COVER AD THIS ISSUE tested Maloney 100 first off quarter scale Cap 20L thai weighed about 15 pounds model first flown 23 cdee rich Zenoah G-23 Frar*ly Maloney 100 would get model trp air could loop level flight model under powered moat people standards Robinhood 80s 12 1/2 ounds fly wel i ntly bulit 90 sized Long John again shortened nose came 10 1/2 pounds model complete flaps fiAt symmetrIcal airfoil model seemingly will maneuver asked flaps down lands about Smiles per hour hope builders smaller Long John will get produce thla sIze kit Weve Modeltech develop two airplanes around Maloney 100 engine Jose StIk Dragon Lady Both modele fly great kept light designed Export 7 ch aystem w14 servos Maloney 100 Robinhood SO Modeltech Dragonlady Modeltech Joss Silk except outsIde loop J 10 1/2 pounds Robinhood will outslde loop very well cut nose back Robinhood 80 put firewal about 1 inch windshleld meets fuselage Notce cowied engine photo model uses small servos still fling 1200mAh battery peck fother reason thanspendalotof out Presently retaling Expert 7 channel system four servos NiCads transmitter flight packs charger neck strap frequency flag $33995 moment might lid retailers -both hobby mail order shops sefling thle system low $15000 terrific buy compared what get some ether systems br kind money fear prIce system will probably going si little bit near future because continuing devaluation US Blail $33995 $19995 $8995 $22495 $15995 j2ZJ u IQ GOQ G2ThLD 8960 Rossash Ave Cincinnati Ohio 45236 Phone 513 793-5900 x 214 557 January 1987 141 JeJtatmtlId maximize performance Maloney 100
Edition: Model Aviation - 1987/01
Page Numbers: 36, 37, 38, 39, 137, 138, 140, 141
Photon Servos two parts move against other destined wear out servos use translates feedback pot begins deterio rate time first moves have searched way avoid mechanical weak link now engineer own ranks may have come up photoelectric feedback system built around Dunham mechanics feedback pot housing has removed arrow points out light-dependent resistors ALMOST EVERY RC FLIER knows what feedback pot Some may have learned about hard way culprit behind crash best piloting skills couldnt have prevented causes trouble other part servo supposed necessary evils wed like able Its little carbon-coated vari able resistor servo has taken apart cleaned lubricated often maintenance isnt done servo arm will eventually become erratic jiggling jumping trying run continuously happens can generally kiss model good-bye feedback potentiometer used continuously-variable voltage divider fixed regulated voltage applied across pot wiper rotated servo motor through reduction gearing voltage divided continuously wiper moves its amplitude completely dependent upon position wiper therefore position output arm voltage governs duration reference pulse generated 36 Model Aviation 1 p-- answer EGeorge Gibson CuttheLDR retaining clipfromatin can lid use CyA glue LDRs place servo compared incoming control pulse receiver duration two pulses identical cancel out servo stops Any irregularity carbon surface pot element depending its character will cause malfunctions addition wiper slides over ele ment gradually wears away primarily over center travel tiny bits wiper metal depositedcausing element behave erratically evil weve put up ever since inception digital RC time Kraft Systems tried eliminate problems feedback pot putting variable capacitor refer ence pulse generator un provement system problems its own should know worked about 10000 Heathkit version servo As trend smaller smaller servos variable capacitors can made small approach phased out meantime quality pots increased price evident pots would always periodic maintenance nuisance Carbon button wiper contacts another im provement button popped out wiper arm saw happen re sulting problems could catastrophic late 1 960s John Cline F&M Electronics experimenting differ ent ways produce servo having incorporate feedback pot outcome research what called variable inductance servo see American Aircraft Modeler February 1968 relatively large metal-cased servo 1 1/16 x January 1987 37 Li Left scale drawing shows clip formed secure LDRs Note rim LDR recessed plastic case Right Remove feedback pot body Dremel tool knife Drill hole #2 screw cut notches wires look closely atthe arrow right can seethe LED peeking through shadow mask has cut hollow output shaft arrow left shows snugly clip holds LDRs Adjust shape clip until sure LDRs cannot move 1 x 3 available linear output eight-pin plug Chine stated research tried photoelectric feedback system before development light-emitting diodes LEDs photoelectrics necessarily de pended filament-type light bulb Cline recognized would im practical four counts mechanism would subject total failure warning whenever filament burned out would have little ability withstand typical model vibrations would cause ex cessive battery drain economically impractical Despite its drawbacks felt would work dont know variable inductance servo ever marketed never saw use photoelectric concept John Cline advanced just waiting technology make practical LEDs light-emitting diodes LDRs light-dependent resistors appeared commercial market couple years after went work Heathkit Co assignments evaluate pre-pro duction run Thumb Tac first photoelectric tachometer appear RC market used transistor-sized pho tocell aforementioned LDRs Thumb Tac developed engineer friend Heath successful both technically com mercially earned him advance grade both members Southwest Michigan Whirlwinds RC Club often discussed possibility using LDR Thumb Tac kit variable resistor reference pulse generator would eliminate trouble some wiping mechanical contacts conventional feedback pot prob lem foresaw LDRs have objectionable warm-up characteristic friend designed special IC chip com pensate LDR drift various reasons eventually dropped project Still idea stuck head decided try another approach keep simple Instead using single LDR requiring special IC retained regnlar Kraft IC used two LDRs series replace feedback pot LDRS carefully matched both would vary resistance same amount same direction During warm-up assuming equal illumination voltage junc tion would remain same junction point course would correspond wiper connection eliminated feed back pot make voltage vary such way simulate movement wiper feedback pot illuminating source would moved away neutral position throw light LDR other voltage junction would rise fall according resistor getting light viable choice light source LED Theyre small immune vibration have very economical current drain theres no filament burn out Almost John Clines problems solved simple device built couple servos using Kraft/ Heath mechanics made LED movable back forth between two LDRs proved concept would work making light source movable required either sliding contacts flexible leads knew inevitably would break cause catastrophic failure both light source light detector stationary moveable mask would have rigged between such way mask moved way other would partially cover uncover LDRs get same effect moving light source would eliminate sliding contacts flexing leads sitting just staring some servo parts constructive idea head suddenly great brainstorm blew through between ears chose servo output gear output shaft might have room gearbox underneath output gear shadow mask knew Dunhams R&R made servo #2 gear located over motor instead under output gear Kraft Heath did ordered four hadnt specified color received white proved problem allowed extraneous light leak onto LDRs tried painting cases black paint worked time flaked off easily Thereafter ordered black cases first successful shadow mask made anodized aluminum glued output shaft required two LEDs although would have increased current drain LEDs series could have simpler Another minor brainstorm resulted putting single LED inside output shaft carving hole side shaft illuminate LDRS As shaft rotated first LDR other would favored light would have effect similar moving light source insert LED bottom end hollow shaft remove short splined shaft attaches pot wiper As brass slug would dis carded along wiper needed devise another way center servo wanted make linearity travel centering adjustable least first few experimental versions O needed second circuit board carry three trimmer pots 50-cent type well some additional resistors capacitors Since no longer needed feedback pot way decided carve off down bottom case make room extra board its parts gave lots room electronics compartment built some ser vos two decks board above other parallel found difficult circuit testing replace parts regrouped ended up two boards mounted right angles mechanics electronics combined oriented shown fit inside servo case gear case cover put first travel adjustments done everything installed case layout has worked out OK far feel production two pots perhaps threecould eliminated single-board electronics would result Replacing troublesome failure-prone feedback pot wasnt simple hoped has definitely worth test-flew three-pot version described over period three years save linkage adjustment set main tenance-free Performance superior hadnt receiver failure causing fatal case fly-away-itis Id flying yet plan patent photon servo Im publicizing notion someone will develop further Adjustments both Kraft Heath servos feedback pot located collector reference pulse generator Its IC its still made up transis tors first substituted LDRs same position travel linearity good tried LDR double base circuit linearity still good Finally put diode base circuit reverse-biased would isolated except base driven neg ative cutoff pulse linearity 38 Model Aviation rough prototype set circuit boards shows perpendicular board layout electronics section vertical board Cir cuit Board #1 available Heathkit other constructed per text better could adjusted 10K pot connected across two LDRs wiper arm attached LDR junc tion Early project found LDR used Thumb Tac suitable servo use since high-resistance type contacted Clairol manufacturer found producing LDRS resistance ranges supplied performance data ordered 10 lowest-resistance range set up test jig Surprise resistance under identical test conditions varied much 300% batch 10 two nearly identical enough servo rest could matched up ordered another 100 got enough matches 29 servos dont have same value just have matched pairs Naturally choices available matches As no longer mechanical feedback pot need alternative method adjust servos centering replaced 1K load resistor collector circuit reference pulse generator inexpensive 2K pot small variation light intensity LDRs will result relatively large change voltage junctionmuch equivalent rotation feed back pot Resistors R2 R3 R4 form network attenuate voltage output arm can rotate farther before control voltage reaches value will result stop Resistor R2 also trimmer pot used adjust length servo travel some later versions mounted LDRs simply gluing place cyanoacrylate CyA units immediately began experience high fail ure rates though two earlier versions LDRs held untidily place wire clips still worked fine Out curiosity added CyA servos next day failed also assume CyA caused failures although dont know Mounting now done sheetmetal clips made top dog food can see pattern have no failures photon servo will draw current standard servo willbut sig nificantly neutral two LDRs will draw maximum about 3 mA LED about 5 mA comparison feedback pot draws 13 mA consider servos typically draw about 20 mA idle least 150 mA under load extra 4 mA insignificant over three years testing have never experienced battery-drain problems schematic parts marked * already installed original circuit board Heath part #238-95 will have make #2 circuit board simple have used three methods con struction Cut-and-peel copper foil very thin PC board material conventional etching non-foil perforated board using bent-over component leads interconnections As two PC boards will assembled 900 other board #2 must notched fit end several sizes 4-watt re sistors market sure get smallest size go -watt com ponents circuit draw enough current get warm trimmer pots used Digi-Key Corp enclosed sealed against dust As 6mm pots take up room #2 board resistors capacitor must carefully located interfere access diagrams should help avoid trouble Also since pots adjustable both top bottom can drill -in holes board pots can set non-component side should first attempt building servo youve successfully assembled kit servos should have little difficulty After boards Heath Some components will left off Heath board incorporated second others will change value type have Heath board already built up can use making necessary modifications Construction After trying servomechan isms several manufacturers decided Dunham D-1 particularly suited purpose has gear arrangement required plus hollow output shaft can modified use shadow-mask gears are of nylon filled Continued page 137 January1987 39 LORs non-polarized either end can connected B LEDs polarized will glow leads reversed Although shown fiat two boards will mounted right angles Note interconnections between two boards LED LDRs q1~ WEIGHT-MATES HEAVY DUTY FABRIC WEIGHT BAGS FOR BUILDING TRANSPORTING & FIELD TIE-DOWN Easily filled w/sand shot up 5 Ibs Five 4x6 bags per package Conforms curvatures Complete instructions $695 postage & handling AZ residents add 35X tas Radio Technique/Myers Continued page 133 transmitter receiver few AM FM sets already conform guidelines So can expect early part 1988 will see low band occupied some pretty good stuff will up keep way vigorously persuading rebels mend ways having equipment serviced periodically keep operating should Based transmitter tests performed three Nats three trade shows seems some AM FM transmitter designs can quali fied slight modifications same informa tion makes seem highly unlikely transmit ters now old channels BN/W through GN/W will ever qualified just basis costs involved Receivers another matter Very few exist ing receivers qualify except Kraft -8FD -8FDS dual-conversion PCM receivers like Simprop PCM-20 Multiplex time gets print expect other qualified receivers will put circula tion Ace R/C Airtronics Circus Futaba others will have own shopping leave reviewing business friend Bob Aberle does very well read Flying Models magazine dont already George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Photon Servos/Gibson Continued page 39 material glass fiber makes very sturdy Dunham guarantees free replace ment part fails reason including crash damage small lots sell approximately $7 lots 100 little over $2 Re member specify black cases order Disassemble servo com pletely careful lose parts particularly small gear pins output gear attached wiper rotor splined brass shaft extends 1GRATE-SHAPES SANDING BLOCKS GS 101 3/u XG5103 K G 5 105 &3k 90Vsw/% X GS 102 /o & m GS 0 %&wR Grit sides Always consistantly rounded edges Long-lasting silicon carbide grit Combo Package 101 102 & 103or specify three $1195 P & H AZ residents add 60 ta Single GRATE-SHAPES $495 P & H AZ residents add 255 tas products guaranteedDealers invited SEND cHECK OR---MONEY ORDER TO Bell Rock Industries Hwy 179-Suite 108 Sedona AZ 86336 284-1808 through bottom gear case Care fully pull upward gear will require some force will separate brass shaft will using shaft wiper project use method want separating damage bearing hole Unless old string saver discard shaft wiper feedback pot body molded integral part servo center section gear case bottom may split several segments can sawed off individually See Fig 4 use Moto Tool cutoff wheel carve stumps flush sharp knife Make two t/ie-in slots Moto cutoff tool drill hole clear #2 screw Now select red LED will fit bottom end output gear shaft LED should wide-angled should fit snugly turn freely flange LED must also sanded off allow inserted deep enough inside shaft Assemble output gear servo top section place LED leads extending down through bearing hole Pull LED down firmly grasping leads put droportwoof5-min epoxy bearing hole around leads use CyA anywhere else servo Let epoxy set firmly before proceeding further remove top section output gear retaining clip two LDRs made top tin can Spring brass bronze could also used dont recommend aluminum case must thin strong Dimensions details given Figs 2 & 3 LDRs will lay flat sides have rim prevents attempt grind flat spot rim though will destroy hermetic seal Instead use defunct metal-cased transis tor same size LED mount place retaining clip heat rim soldering iron until plastic melts E -% BOOSTER Space Age Charging Has Arnvedl Convenient solar charging will solve battery charging problems flying sight boosting batteries between flights Safe 100 MA Charge Rate Autumatic Cat-OS Full Charge High Efficiency Under Cloudy Cosditioou Charges-Both RX asd TX Simultaneously Popular Radio Systems Using 48 96 Volts Handy Plug-In Charging Cord Adjustable Angle Bracket Bailt Everyday Use RaggedLightweighl Easy Curry Handle Full Warranty $7995 Introductory Dtter $450 Shipping & Handling USA AZ Residents Add $400 Tax allows rim sink surface too much heat youll ruin plastic case recess melted case LDRs can now made set flat held place retaining clip Mount shown Fig 5 bending bottom lead LDR downward through Yt6-in slots other lead LDR will bent forward two joined can soldered retaining clip desired junction green wire board #2 will later soldered removing flange LED during its installation also removed flat flange identifies cathode lead install diode properly must re-identify lead connect two wires positive negative outputs flight battery solder 1000-ohm resistor end positive lead Touch negative wire LED lead free end 1K resistor other lead LED does light reverse connections LED lights lead going 1K resistor anode other lead cathode Bend cathode lead over flat solder lead LDR2 comes through slot Later black wire board #2 will connected also Now shadow mask Look bottom side output gear neutral point raised ridge about e-in wide radiating shaft out ward rim Take sharp point scribe line shaft center ridge downward bottom end shaft parallel its axis point line om end make tiny punch mark drill hole through shaft wall Enlarge hole /u6-in drill %2-in drill Dont drill through both sides shaft though Square up hole sharp X-Acto blade shadow mask complete January 1987 137 DGADelignsss OGA Designs DGA Designs. DGA Designs es DGA Designs o5 S *DARNED GOOD AIRMEN Lightest weight Pilots Available Ia0 * FULL BODY PILOT KIT e ke Vny e abbe pa-ts Easy assenble finish Kit contains Pilot head hands boots heintet5 Ocap goggles full tentplates easy inett-ttctiOns Fully positionable too0 Height- Weight-NEW LOW Pttces-5 NO206 .1/6 Scale lls 2 oz s72 rJ\rK NO206 5 Scale 14 3oz s89 No204-1/4 Scale 174 ozs 99501 V[7V kJO 203 13 Scale 236ozsI6 100 55PORT5MAN o BARNSTORMER- FULL RODS Oo RUSTfl/C C *s4J5 PILOT KIT LitSike 0OV lOthS 055t, pad,0 Ktt csntates PAst head hornet spod cap gossips OJacket. Easy asoornitie aho tjhsh Height WeightLOW Peicee5 ,No1O9t OScaip310Otoa5 59/5 4 No tOO t SRCOieO8tI 400sd%hc NO 04- aScaleadottao7Sh*sOme01 No tOg t iScale5-34240sl4~ simple tOsewtng5 Astounding htOliOeqt4irea0 4 attainable plastics.. ODoe tothete5temeti9et Weight Oat trntpiotcatoii ooa5o idiOt 0boOtS WiicaoeitttieothoettoctohthetaihctOtVootaiCatt 0 Send slOO Catalog SI Ne YOtt state RoOdoots add 75 sales tOO. Send Check ot- MO. cO Os Ai Oss 3 seeks cseck toctear 5 s DGA Designs 5 5 DGA 55 OGA Designs Reassembling gear train takes little sleight hand Put servo top section top cover separate Dunham D-l As top cover will remain place unassisted until case bottom can fastened wrap some tape around assembly retain cover no light can get Shorten remaining free lead CL-2 LATCH FOR COAL ItATCtI CAGtOPY & tdIttO AINPIN 2-STAGE PRESSURE STAG MORE GOODIES CANOPY TRACK AIRPIN PRESS GUAGE CUSTOM Ant CYLINDERS PROPHUT/SPINHER ATTACH EXT PROPEUTS FUR P-It PItU ete &IE OPERATES LATCH tTLAS Oev F2tGfltES STItoNGI ltD TIMER KITS SEND SASE FOR INFO DEALER INQUIRIES INVITED PHORE3O 73161 ROBINAIR E P 0 80X8770 CORAL SPRINGS FLORIDA33O75 MINICYLINDERS LED anode make soldering loop will later attach blue wire coming board #1 install motor point Rotate gears output gear neutral put output arm onto shaft neutral also Leave out arm retaining screw servo completed power should see bright red glow LED look down through top shaft Circuit board assembly As mentioned before circuit board #1 actually Heathkit part #238-95 using pre assembled board Heath servo leave following parts board power transistors motor leads servo con necting cable plug 1 0sF tantalum capacitor some units 22F 47F tantalum capacitor 001/LF ceramic capacitor IC Remove other parts Clip parts off above board try salvage Cut off flush top surface board will now very easy unsolder remaining stumps shake off board ruining foils process starting new board mount IC first being sure correctly oriented foil pad very narrow extends around three edges board 48-volt foil notched indented end IC will go middle section foil #1 pin will connect foil directly have provided diagram foil pattern copyrighted have identified holes use lettering top view board Fig 6 Assuming using red white black green color-coded servo connecting cable Heath has always used connect red wire hole marked B nearest pin #1 IC cases told connect wire component solder joint though another connection made later point system uses different color code youre own Connect black wire cable hole W also marked B- Connect green wire hole N nearest IC pin #12 cable has white wire clip plug strip out cable Use later needed Install two MPS6562 transistors leads marked transistor body EBC must go hole labeled corresponding letter see diagram sure leads short enough transistor does stand above board Install 47MF tantalum capacitor plus lead going hole T minus lead through hole U can use metal-cased type Heath used used dipped tantalum because fits better precision capacitor re quired Install OO1tF 1000 pF capacitor holes R S Heath used tubular unit used tiny disc capacitor Digi-Key just fits Again precision point required Install lOOK resistor RiO body standing up vertically hole X top lead bent over sharply enter hole Y 1 0MF 22FF dipped tantalum capacitor also destined holes X Y will installed later Install 82K resistor holes K L may necessary change value resistor depending servo operates place 22tF capacitor originally used holes F H install 1N914 diode F unbanded end down board left standing vertically later insertion #2 board Lay #1 board aside Prepare #2 board check shorts Borrow ohmmeter have set R x 1000 Touch meter lead foil pads touch other lead successively foil pad bordering first meter does deflect move another foil pad test its neighboring pads same man ner two foils produce indication short use X-Acto knife cut dividing lines deeper remove short sure absolutely no shorts between two foil pads proceed installation electronic components Install two 10K trimpots proper places non-foil side board should stand about %2-in high no Install R6 220K lies along left side board Position body resistor installed will act insulator against bare lead R3 Install two short bits bare wire holes opposite sides clearance notch end board Continued page 140 138 Model Aviation 45 m GEAR MECHANICS FOR BIGGIES Now Can Drill Grind Cut Sand Polish IN PLACES YOU NE VER COULD BEFORE FiRST TIME AVAILABLE great new precision tool has tough ABS housing hardened metal gears Iltetime lubricated bearings Attaches seconds Dremei Moto-Tool models #270 #280 #370 #380 Sears Craftsman rotary tools MUST FOR THE SMALL TOOL WORK SHOP R NOW AND SAVE Use thin onu~ send name addresn payment MICROUARKS Box 5112-3l3eCllnton NJ 08808 E Send n, 'a YES Send ______ RIGHT ANGLE DRIVES Item #50353 24-HOUR CREDIT CARD PI4ONEt 1400-225-1066 $1700 plus $200 shipphig andemtand dl am mm- lEt NJ 201-4644764 pletely satisfied may retum order en immediate refund NAME_______________________________ [ICheclr enclesed NJ residettla add 6% nolan tan [Charge [I VISA [I MaulerCard []AMEX ADDRESS___________________________________ Aoct#_____________________ [I Ship order C 00 $200 additionalCIlYSTATE______ ZIP ______ will connect #2 ground foil #1 ground B other will connect #2 22-volt B foil 22-volt pin IC Install R3 2200 ohms stand ver tically bend bare lead necessary go under R6 Install R4 2200 ohms flat board laid down Install R7 lOOK position shown Install C6 22tF dipped tantalum short negative lead board Leave positive lead long can connected board #1 later Cut 1-in length stranded orange wire Bare end twist strands together before soldering make insertion circuit board holes easier Connect end circuit foil board #2 shown Cut 2-in lengths blue black green orange wire prepare described previously 1-in stranded wire Connect blue wire top ofRi board #1 green black orange wires board #2 shown top Fig 5 Mount board #2 proper end board #1 components of#2 will overhang of# 1 short bits ofbare wire previously soldered lower end #2 should now bent downward fit vacant holes board #1 boards should form right angle notch board #2 should fit over end IC flush end Feed entire length positive lead 1 N9 14 diode through hole X board #2 Cover lead Teflon tubing bend over connect foil pad same place bare lead R7 connected Solder clip off excess lead Install lMF polyester capacitor Cl holes X andY lead goes through same hole used 1N914 diode Solder diode lead clip off excess wire leads must belong enough capacitor straddles top R3 Bend lead going through hole Y solder wiper terminal pot R8 Connect free end 1-in orange wire hole H shown Fig 6 other wires black green blue orange go LED-LDR photoelectric assembly gear case compartment Terminals assembly brought through gear case bottom feedback pot body removed Cut two pieces wire brown other white length 1 in, prepare ends before Put brown wire through hole M white wire through hole AZ Connect other ends wires motor follows white red positive terminal brown other terminal Connect CS 05F cer amic disc across motor terminals leads CS should left long enough extend down sides motor out way lead going red terminal must insulated other lead can left bare must grounded case Except connections photo electric assembly circuit board work now finished black wire connected junction LED LDR leads green wire junction LDRs orange wire remaining LDR lead blue wire anode re maining free end LED See ex planation Fig 5 motor removed pops right out gear train engaged plug servo receiver servooperator Turn power look down through top output shaft should see bright glow LED Though have built unit correctly will still almost certainly completely out adjustment Leave motor out gear box ie installed servo top section top cover place over gears photoelectric assembly Take off case bottom turn power motor should run transmitter off might initial twitch will run continuously until transmitter turned motor does begin run smoke LED does glow have defect construction Unplug servo look solder bridges misplaced parts other things electronics kits caution about unit OK far PRODUCTS FOR TIW n tmau Mf Unflet lete Line Exhaust Systems Tuned Pipes led Tuned Pipes Headers uri Mufflers Expansion Mufflers Helicopter Ball Mufflers ialized Exhaust Systems Unsurpassad Wnk,smnohin F Prftrmanc 140 Model Aviation New Robart RIGHT ANGLE DRIVE Dremel Moto-Tools U motor running turn transmitter motor will likely run direction unless struck lucky will stop reverse move control stick Shut receiver off adjust travel pot R2 extreme right its range looking top point maximum travel will reduce later procedure Make sure both transmitter receiver set servo arm neutral center adjust centering pot R8 point motor either stops oscillates Shut off receiver engage motor gear train Turn receiver back output arm runs side wont come back reverse leads motor start over correct motor connection may result servo arm oscillating though no command has given phenome non should cease travel pot readjusted now set travel pot mid-range arm comes rest point off-center set linearity pot R5 center positioning servo arm Now check 450 travel side center travel control affects total amount travel linearity control affects amount travel side center three controls centering linearity travel interact affects others may necessary go over several times Dont strive perfection making adjustments though because wont get finished servo oscillates IC may sensitive ones requires change 82Kresistor R9 value 68K 56K does oscillate fact seems underpowered change R9 either lOOK 120K changes will require small amount recentering given sudden large amounts stick action under no-load conditions servo will overshoot immediately re turn commanded position due lag response time LDRs confronted sudden large change brightness Since servos modeling environment rarely operate out some kind load would appear no problem Although further development servo might result eliminating two pots would seem 2K centering pot will always need retained can visualize though unit lower part output shaft shadow mask could independently adjustable respect output gear itself would friction adjustment could set top servo just servos now would require some delicate machining Im working Im also process trying adapt photoelectric concept use Signetics NE544 IC have little luck servo operates perfectly itself used other servos kind causes buzz jump oscillate Signetics chip does require additional external transistors does Kraft IC appeal smaller lighter still has experimenting have questions comments please write author George Gibson RR 1 Box 157 Fountain MI 49410 RC Soaring/Blakeslee Continued page 41 AMA did recognize Soaring time contest became bigger single AMA event premier event year event run Dan drew over 200 com petitors over country com petition its finest meet names like Mark Smith Dave Shadel Otto Heithecker Don Edberg Warren Plohr LeMon Payne Col Bob Thacker John Baxter Dave Thornburg Bob Gill Dale Nutter Jeff Mrlik Dwight Holly people flew against another single major contest today Glider pilots travel AMA Nats like did SOAR Nationals Dan Pruss ran class contest participation SOAR Nats reasons Soaring finally added AMA event Thank Dan Pruss will always treasure people experiences because Kurt Rosner fellow Rocky Mountain Soaring Association member favorite bird shot down off-field interference prompted Kurt try find Out what hit him So went out bought frequency scanner found commercial station operating 10 kHz below channel 44 First lets have Kurt describe scanner Regency MX500 may first readily-available new breed communica tions receivercontinuous coverage 25 550 MHz Other receivers give several seg ments bands within range dont give access example RC channels 72 MHz does frequency-synthesized no crystals keyboard-controlled alphanumeric LCD display comes nifty compact package can program 20-channel scanner set up search between two frequencies steps 5 125 25 kHz AM NFM WFM narrow- wide-band FM can selected example might want program up 20 RC channels Scan mode Search 720 730 MHz 5 kHz steps find potentially troublemaking signals lurking between RC channels area MX500 comes plug-in telescoping antenna 120-volt adapter cable install cigarette-lighter plug whatever cars 12-volt battery mounting bracket got CW Electronic Sales Denver $299 recently reduced $415 first hit market $600 Two nega tives instruction book skimpy doesnt cover keyboard-control capabilities unit Second little gem may distract real hobby Its imported Regency Electronics Inc 7707 Records St Indianapolis IN 46226 Kurts second step contact District IX Frequency Coordinator Steve Mangles lives Denver Steve found offender mobile phone service broadcasting data voice signals directionally Denver towards Boulder Kurt got hit Small consolation Kurt can hear signal loud clear new scanner Steve also learned same company L7ZY U L2 2U OOO LYUJLiI9 SEE OUR BACK COVER AD THIS ISSUE tested Maloney 100 first off quarter scale Cap 20L thai weighed about 15 pounds model first flown 23 cdee rich Zenoah G-23 Frar*ly Maloney 100 would get model trp air could loop level flight model under powered moat people standards Robinhood 80s 12 1/2 ounds fly wel i ntly bulit 90 sized Long John again shortened nose came 10 1/2 pounds model complete flaps fiAt symmetrIcal airfoil model seemingly will maneuver asked flaps down lands about Smiles per hour hope builders smaller Long John will get produce thla sIze kit Weve Modeltech develop two airplanes around Maloney 100 engine Jose StIk Dragon Lady Both modele fly great kept light designed Export 7 ch aystem w14 servos Maloney 100 Robinhood SO Modeltech Dragonlady Modeltech Joss Silk except outsIde loop J 10 1/2 pounds Robinhood will outslde loop very well cut nose back Robinhood 80 put firewal about 1 inch windshleld meets fuselage Notce cowied engine photo model uses small servos still fling 1200mAh battery peck fother reason thanspendalotof out Presently retaling Expert 7 channel system four servos NiCads transmitter flight packs charger neck strap frequency flag $33995 moment might lid retailers -both hobby mail order shops sefling thle system low $15000 terrific buy compared what get some ether systems br kind money fear prIce system will probably going si little bit near future because continuing devaluation US Blail $33995 $19995 $8995 $22495 $15995 j2ZJ u IQ GOQ G2ThLD 8960 Rossash Ave Cincinnati Ohio 45236 Phone 513 793-5900 x 214 557 January 1987 141 JeJtatmtlId maximize performance Maloney 100
Edition: Model Aviation - 1987/01
Page Numbers: 36, 37, 38, 39, 137, 138, 140, 141
Photon Servos two parts move against other destined wear out servos use translates feedback pot begins deterio rate time first moves have searched way avoid mechanical weak link now engineer own ranks may have come up photoelectric feedback system built around Dunham mechanics feedback pot housing has removed arrow points out light-dependent resistors ALMOST EVERY RC FLIER knows what feedback pot Some may have learned about hard way culprit behind crash best piloting skills couldnt have prevented causes trouble other part servo supposed necessary evils wed like able Its little carbon-coated vari able resistor servo has taken apart cleaned lubricated often maintenance isnt done servo arm will eventually become erratic jiggling jumping trying run continuously happens can generally kiss model good-bye feedback potentiometer used continuously-variable voltage divider fixed regulated voltage applied across pot wiper rotated servo motor through reduction gearing voltage divided continuously wiper moves its amplitude completely dependent upon position wiper therefore position output arm voltage governs duration reference pulse generated 36 Model Aviation 1 p-- answer EGeorge Gibson CuttheLDR retaining clipfromatin can lid use CyA glue LDRs place servo compared incoming control pulse receiver duration two pulses identical cancel out servo stops Any irregularity carbon surface pot element depending its character will cause malfunctions addition wiper slides over ele ment gradually wears away primarily over center travel tiny bits wiper metal depositedcausing element behave erratically evil weve put up ever since inception digital RC time Kraft Systems tried eliminate problems feedback pot putting variable capacitor refer ence pulse generator un provement system problems its own should know worked about 10000 Heathkit version servo As trend smaller smaller servos variable capacitors can made small approach phased out meantime quality pots increased price evident pots would always periodic maintenance nuisance Carbon button wiper contacts another im provement button popped out wiper arm saw happen re sulting problems could catastrophic late 1 960s John Cline F&M Electronics experimenting differ ent ways produce servo having incorporate feedback pot outcome research what called variable inductance servo see American Aircraft Modeler February 1968 relatively large metal-cased servo 1 1/16 x January 1987 37 Li Left scale drawing shows clip formed secure LDRs Note rim LDR recessed plastic case Right Remove feedback pot body Dremel tool knife Drill hole #2 screw cut notches wires look closely atthe arrow right can seethe LED peeking through shadow mask has cut hollow output shaft arrow left shows snugly clip holds LDRs Adjust shape clip until sure LDRs cannot move 1 x 3 available linear output eight-pin plug Chine stated research tried photoelectric feedback system before development light-emitting diodes LEDs photoelectrics necessarily de pended filament-type light bulb Cline recognized would im practical four counts mechanism would subject total failure warning whenever filament burned out would have little ability withstand typical model vibrations would cause ex cessive battery drain economically impractical Despite its drawbacks felt would work dont know variable inductance servo ever marketed never saw use photoelectric concept John Cline advanced just waiting technology make practical LEDs light-emitting diodes LDRs light-dependent resistors appeared commercial market couple years after went work Heathkit Co assignments evaluate pre-pro duction run Thumb Tac first photoelectric tachometer appear RC market used transistor-sized pho tocell aforementioned LDRs Thumb Tac developed engineer friend Heath successful both technically com mercially earned him advance grade both members Southwest Michigan Whirlwinds RC Club often discussed possibility using LDR Thumb Tac kit variable resistor reference pulse generator would eliminate trouble some wiping mechanical contacts conventional feedback pot prob lem foresaw LDRs have objectionable warm-up characteristic friend designed special IC chip com pensate LDR drift various reasons eventually dropped project Still idea stuck head decided try another approach keep simple Instead using single LDR requiring special IC retained regnlar Kraft IC used two LDRs series replace feedback pot LDRS carefully matched both would vary resistance same amount same direction During warm-up assuming equal illumination voltage junc tion would remain same junction point course would correspond wiper connection eliminated feed back pot make voltage vary such way simulate movement wiper feedback pot illuminating source would moved away neutral position throw light LDR other voltage junction would rise fall according resistor getting light viable choice light source LED Theyre small immune vibration have very economical current drain theres no filament burn out Almost John Clines problems solved simple device built couple servos using Kraft/ Heath mechanics made LED movable back forth between two LDRs proved concept would work making light source movable required either sliding contacts flexible leads knew inevitably would break cause catastrophic failure both light source light detector stationary moveable mask would have rigged between such way mask moved way other would partially cover uncover LDRs get same effect moving light source would eliminate sliding contacts flexing leads sitting just staring some servo parts constructive idea head suddenly great brainstorm blew through between ears chose servo output gear output shaft might have room gearbox underneath output gear shadow mask knew Dunhams R&R made servo #2 gear located over motor instead under output gear Kraft Heath did ordered four hadnt specified color received white proved problem allowed extraneous light leak onto LDRs tried painting cases black paint worked time flaked off easily Thereafter ordered black cases first successful shadow mask made anodized aluminum glued output shaft required two LEDs although would have increased current drain LEDs series could have simpler Another minor brainstorm resulted putting single LED inside output shaft carving hole side shaft illuminate LDRS As shaft rotated first LDR other would favored light would have effect similar moving light source insert LED bottom end hollow shaft remove short splined shaft attaches pot wiper As brass slug would dis carded along wiper needed devise another way center servo wanted make linearity travel centering adjustable least first few experimental versions O needed second circuit board carry three trimmer pots 50-cent type well some additional resistors capacitors Since no longer needed feedback pot way decided carve off down bottom case make room extra board its parts gave lots room electronics compartment built some ser vos two decks board above other parallel found difficult circuit testing replace parts regrouped ended up two boards mounted right angles mechanics electronics combined oriented shown fit inside servo case gear case cover put first travel adjustments done everything installed case layout has worked out OK far feel production two pots perhaps threecould eliminated single-board electronics would result Replacing troublesome failure-prone feedback pot wasnt simple hoped has definitely worth test-flew three-pot version described over period three years save linkage adjustment set main tenance-free Performance superior hadnt receiver failure causing fatal case fly-away-itis Id flying yet plan patent photon servo Im publicizing notion someone will develop further Adjustments both Kraft Heath servos feedback pot located collector reference pulse generator Its IC its still made up transis tors first substituted LDRs same position travel linearity good tried LDR double base circuit linearity still good Finally put diode base circuit reverse-biased would isolated except base driven neg ative cutoff pulse linearity 38 Model Aviation rough prototype set circuit boards shows perpendicular board layout electronics section vertical board Cir cuit Board #1 available Heathkit other constructed per text better could adjusted 10K pot connected across two LDRs wiper arm attached LDR junc tion Early project found LDR used Thumb Tac suitable servo use since high-resistance type contacted Clairol manufacturer found producing LDRS resistance ranges supplied performance data ordered 10 lowest-resistance range set up test jig Surprise resistance under identical test conditions varied much 300% batch 10 two nearly identical enough servo rest could matched up ordered another 100 got enough matches 29 servos dont have same value just have matched pairs Naturally choices available matches As no longer mechanical feedback pot need alternative method adjust servos centering replaced 1K load resistor collector circuit reference pulse generator inexpensive 2K pot small variation light intensity LDRs will result relatively large change voltage junctionmuch equivalent rotation feed back pot Resistors R2 R3 R4 form network attenuate voltage output arm can rotate farther before control voltage reaches value will result stop Resistor R2 also trimmer pot used adjust length servo travel some later versions mounted LDRs simply gluing place cyanoacrylate CyA units immediately began experience high fail ure rates though two earlier versions LDRs held untidily place wire clips still worked fine Out curiosity added CyA servos next day failed also assume CyA caused failures although dont know Mounting now done sheetmetal clips made top dog food can see pattern have no failures photon servo will draw current standard servo willbut sig nificantly neutral two LDRs will draw maximum about 3 mA LED about 5 mA comparison feedback pot draws 13 mA consider servos typically draw about 20 mA idle least 150 mA under load extra 4 mA insignificant over three years testing have never experienced battery-drain problems schematic parts marked * already installed original circuit board Heath part #238-95 will have make #2 circuit board simple have used three methods con struction Cut-and-peel copper foil very thin PC board material conventional etching non-foil perforated board using bent-over component leads interconnections As two PC boards will assembled 900 other board #2 must notched fit end several sizes 4-watt re sistors market sure get smallest size go -watt com ponents circuit draw enough current get warm trimmer pots used Digi-Key Corp enclosed sealed against dust As 6mm pots take up room #2 board resistors capacitor must carefully located interfere access diagrams should help avoid trouble Also since pots adjustable both top bottom can drill -in holes board pots can set non-component side should first attempt building servo youve successfully assembled kit servos should have little difficulty After boards Heath Some components will left off Heath board incorporated second others will change value type have Heath board already built up can use making necessary modifications Construction After trying servomechan isms several manufacturers decided Dunham D-1 particularly suited purpose has gear arrangement required plus hollow output shaft can modified use shadow-mask gears are of nylon filled Continued page 137 January1987 39 LORs non-polarized either end can connected B LEDs polarized will glow leads reversed Although shown fiat two boards will mounted right angles Note interconnections between two boards LED LDRs q1~ WEIGHT-MATES HEAVY DUTY FABRIC WEIGHT BAGS FOR BUILDING TRANSPORTING & FIELD TIE-DOWN Easily filled w/sand shot up 5 Ibs Five 4x6 bags per package Conforms curvatures Complete instructions $695 postage & handling AZ residents add 35X tas Radio Technique/Myers Continued page 133 transmitter receiver few AM FM sets already conform guidelines So can expect early part 1988 will see low band occupied some pretty good stuff will up keep way vigorously persuading rebels mend ways having equipment serviced periodically keep operating should Based transmitter tests performed three Nats three trade shows seems some AM FM transmitter designs can quali fied slight modifications same informa tion makes seem highly unlikely transmit ters now old channels BN/W through GN/W will ever qualified just basis costs involved Receivers another matter Very few exist ing receivers qualify except Kraft -8FD -8FDS dual-conversion PCM receivers like Simprop PCM-20 Multiplex time gets print expect other qualified receivers will put circula tion Ace R/C Airtronics Circus Futaba others will have own shopping leave reviewing business friend Bob Aberle does very well read Flying Models magazine dont already George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Photon Servos/Gibson Continued page 39 material glass fiber makes very sturdy Dunham guarantees free replace ment part fails reason including crash damage small lots sell approximately $7 lots 100 little over $2 Re member specify black cases order Disassemble servo com pletely careful lose parts particularly small gear pins output gear attached wiper rotor splined brass shaft extends 1GRATE-SHAPES SANDING BLOCKS GS 101 3/u XG5103 K G 5 105 &3k 90Vsw/% X GS 102 /o & m GS 0 %&wR Grit sides Always consistantly rounded edges Long-lasting silicon carbide grit Combo Package 101 102 & 103or specify three $1195 P & H AZ residents add 60 ta Single GRATE-SHAPES $495 P & H AZ residents add 255 tas products guaranteedDealers invited SEND cHECK OR---MONEY ORDER TO Bell Rock Industries Hwy 179-Suite 108 Sedona AZ 86336 284-1808 through bottom gear case Care fully pull upward gear will require some force will separate brass shaft will using shaft wiper project use method want separating damage bearing hole Unless old string saver discard shaft wiper feedback pot body molded integral part servo center section gear case bottom may split several segments can sawed off individually See Fig 4 use Moto Tool cutoff wheel carve stumps flush sharp knife Make two t/ie-in slots Moto cutoff tool drill hole clear #2 screw Now select red LED will fit bottom end output gear shaft LED should wide-angled should fit snugly turn freely flange LED must also sanded off allow inserted deep enough inside shaft Assemble output gear servo top section place LED leads extending down through bearing hole Pull LED down firmly grasping leads put droportwoof5-min epoxy bearing hole around leads use CyA anywhere else servo Let epoxy set firmly before proceeding further remove top section output gear retaining clip two LDRs made top tin can Spring brass bronze could also used dont recommend aluminum case must thin strong Dimensions details given Figs 2 & 3 LDRs will lay flat sides have rim prevents attempt grind flat spot rim though will destroy hermetic seal Instead use defunct metal-cased transis tor same size LED mount place retaining clip heat rim soldering iron until plastic melts E -% BOOSTER Space Age Charging Has Arnvedl Convenient solar charging will solve battery charging problems flying sight boosting batteries between flights Safe 100 MA Charge Rate Autumatic Cat-OS Full Charge High Efficiency Under Cloudy Cosditioou Charges-Both RX asd TX Simultaneously Popular Radio Systems Using 48 96 Volts Handy Plug-In Charging Cord Adjustable Angle Bracket Bailt Everyday Use RaggedLightweighl Easy Curry Handle Full Warranty $7995 Introductory Dtter $450 Shipping & Handling USA AZ Residents Add $400 Tax allows rim sink surface too much heat youll ruin plastic case recess melted case LDRs can now made set flat held place retaining clip Mount shown Fig 5 bending bottom lead LDR downward through Yt6-in slots other lead LDR will bent forward two joined can soldered retaining clip desired junction green wire board #2 will later soldered removing flange LED during its installation also removed flat flange identifies cathode lead install diode properly must re-identify lead connect two wires positive negative outputs flight battery solder 1000-ohm resistor end positive lead Touch negative wire LED lead free end 1K resistor other lead LED does light reverse connections LED lights lead going 1K resistor anode other lead cathode Bend cathode lead over flat solder lead LDR2 comes through slot Later black wire board #2 will connected also Now shadow mask Look bottom side output gear neutral point raised ridge about e-in wide radiating shaft out ward rim Take sharp point scribe line shaft center ridge downward bottom end shaft parallel its axis point line om end make tiny punch mark drill hole through shaft wall Enlarge hole /u6-in drill %2-in drill Dont drill through both sides shaft though Square up hole sharp X-Acto blade shadow mask complete January 1987 137 DGADelignsss OGA Designs DGA Designs. DGA Designs es DGA Designs o5 S *DARNED GOOD AIRMEN Lightest weight Pilots Available Ia0 * FULL BODY PILOT KIT e ke Vny e abbe pa-ts Easy assenble finish Kit contains Pilot head hands boots heintet5 Ocap goggles full tentplates easy inett-ttctiOns Fully positionable too0 Height- Weight-NEW LOW Pttces-5 NO206 .1/6 Scale lls 2 oz s72 rJ\rK NO206 5 Scale 14 3oz s89 No204-1/4 Scale 174 ozs 99501 V[7V kJO 203 13 Scale 236ozsI6 100 55PORT5MAN o BARNSTORMER- FULL RODS Oo RUSTfl/C C *s4J5 PILOT KIT LitSike 0OV lOthS 055t, pad,0 Ktt csntates PAst head hornet spod cap gossips OJacket. Easy asoornitie aho tjhsh Height WeightLOW Peicee5 ,No1O9t OScaip310Otoa5 59/5 4 No tOO t SRCOieO8tI 400sd%hc NO 04- aScaleadottao7Sh*sOme01 No tOg t iScale5-34240sl4~ simple tOsewtng5 Astounding htOliOeqt4irea0 4 attainable plastics.. ODoe tothete5temeti9et Weight Oat trntpiotcatoii ooa5o idiOt 0boOtS WiicaoeitttieothoettoctohthetaihctOtVootaiCatt 0 Send slOO Catalog SI Ne YOtt state RoOdoots add 75 sales tOO. Send Check ot- MO. cO Os Ai Oss 3 seeks cseck toctear 5 s DGA Designs 5 5 DGA 55 OGA Designs Reassembling gear train takes little sleight hand Put servo top section top cover separate Dunham D-l As top cover will remain place unassisted until case bottom can fastened wrap some tape around assembly retain cover no light can get Shorten remaining free lead CL-2 LATCH FOR COAL ItATCtI CAGtOPY & tdIttO AINPIN 2-STAGE PRESSURE STAG MORE GOODIES CANOPY TRACK AIRPIN PRESS GUAGE CUSTOM Ant CYLINDERS PROPHUT/SPINHER ATTACH EXT PROPEUTS FUR P-It PItU ete &IE OPERATES LATCH tTLAS Oev F2tGfltES STItoNGI ltD TIMER KITS SEND SASE FOR INFO DEALER INQUIRIES INVITED PHORE3O 73161 ROBINAIR E P 0 80X8770 CORAL SPRINGS FLORIDA33O75 MINICYLINDERS LED anode make soldering loop will later attach blue wire coming board #1 install motor point Rotate gears output gear neutral put output arm onto shaft neutral also Leave out arm retaining screw servo completed power should see bright red glow LED look down through top shaft Circuit board assembly As mentioned before circuit board #1 actually Heathkit part #238-95 using pre assembled board Heath servo leave following parts board power transistors motor leads servo con necting cable plug 1 0sF tantalum capacitor some units 22F 47F tantalum capacitor 001/LF ceramic capacitor IC Remove other parts Clip parts off above board try salvage Cut off flush top surface board will now very easy unsolder remaining stumps shake off board ruining foils process starting new board mount IC first being sure correctly oriented foil pad very narrow extends around three edges board 48-volt foil notched indented end IC will go middle section foil #1 pin will connect foil directly have provided diagram foil pattern copyrighted have identified holes use lettering top view board Fig 6 Assuming using red white black green color-coded servo connecting cable Heath has always used connect red wire hole marked B nearest pin #1 IC cases told connect wire component solder joint though another connection made later point system uses different color code youre own Connect black wire cable hole W also marked B- Connect green wire hole N nearest IC pin #12 cable has white wire clip plug strip out cable Use later needed Install two MPS6562 transistors leads marked transistor body EBC must go hole labeled corresponding letter see diagram sure leads short enough transistor does stand above board Install 47MF tantalum capacitor plus lead going hole T minus lead through hole U can use metal-cased type Heath used used dipped tantalum because fits better precision capacitor re quired Install OO1tF 1000 pF capacitor holes R S Heath used tubular unit used tiny disc capacitor Digi-Key just fits Again precision point required Install lOOK resistor RiO body standing up vertically hole X top lead bent over sharply enter hole Y 1 0MF 22FF dipped tantalum capacitor also destined holes X Y will installed later Install 82K resistor holes K L may necessary change value resistor depending servo operates place 22tF capacitor originally used holes F H install 1N914 diode F unbanded end down board left standing vertically later insertion #2 board Lay #1 board aside Prepare #2 board check shorts Borrow ohmmeter have set R x 1000 Touch meter lead foil pads touch other lead successively foil pad bordering first meter does deflect move another foil pad test its neighboring pads same man ner two foils produce indication short use X-Acto knife cut dividing lines deeper remove short sure absolutely no shorts between two foil pads proceed installation electronic components Install two 10K trimpots proper places non-foil side board should stand about %2-in high no Install R6 220K lies along left side board Position body resistor installed will act insulator against bare lead R3 Install two short bits bare wire holes opposite sides clearance notch end board Continued page 140 138 Model Aviation 45 m GEAR MECHANICS FOR BIGGIES Now Can Drill Grind Cut Sand Polish IN PLACES YOU NE VER COULD BEFORE FiRST TIME AVAILABLE great new precision tool has tough ABS housing hardened metal gears Iltetime lubricated bearings Attaches seconds Dremei Moto-Tool models #270 #280 #370 #380 Sears Craftsman rotary tools MUST FOR THE SMALL TOOL WORK SHOP R NOW AND SAVE Use thin onu~ send name addresn payment MICROUARKS Box 5112-3l3eCllnton NJ 08808 E Send n, 'a YES Send ______ RIGHT ANGLE DRIVES Item #50353 24-HOUR CREDIT CARD PI4ONEt 1400-225-1066 $1700 plus $200 shipphig andemtand dl am mm- lEt NJ 201-4644764 pletely satisfied may retum order en immediate refund NAME_______________________________ [ICheclr enclesed NJ residettla add 6% nolan tan [Charge [I VISA [I MaulerCard []AMEX ADDRESS___________________________________ Aoct#_____________________ [I Ship order C 00 $200 additionalCIlYSTATE______ ZIP ______ will connect #2 ground foil #1 ground B other will connect #2 22-volt B foil 22-volt pin IC Install R3 2200 ohms stand ver tically bend bare lead necessary go under R6 Install R4 2200 ohms flat board laid down Install R7 lOOK position shown Install C6 22tF dipped tantalum short negative lead board Leave positive lead long can connected board #1 later Cut 1-in length stranded orange wire Bare end twist strands together before soldering make insertion circuit board holes easier Connect end circuit foil board #2 shown Cut 2-in lengths blue black green orange wire prepare described previously 1-in stranded wire Connect blue wire top ofRi board #1 green black orange wires board #2 shown top Fig 5 Mount board #2 proper end board #1 components of#2 will overhang of# 1 short bits ofbare wire previously soldered lower end #2 should now bent downward fit vacant holes board #1 boards should form right angle notch board #2 should fit over end IC flush end Feed entire length positive lead 1 N9 14 diode through hole X board #2 Cover lead Teflon tubing bend over connect foil pad same place bare lead R7 connected Solder clip off excess lead Install lMF polyester capacitor Cl holes X andY lead goes through same hole used 1N914 diode Solder diode lead clip off excess wire leads must belong enough capacitor straddles top R3 Bend lead going through hole Y solder wiper terminal pot R8 Connect free end 1-in orange wire hole H shown Fig 6 other wires black green blue orange go LED-LDR photoelectric assembly gear case compartment Terminals assembly brought through gear case bottom feedback pot body removed Cut two pieces wire brown other white length 1 in, prepare ends before Put brown wire through hole M white wire through hole AZ Connect other ends wires motor follows white red positive terminal brown other terminal Connect CS 05F cer amic disc across motor terminals leads CS should left long enough extend down sides motor out way lead going red terminal must insulated other lead can left bare must grounded case Except connections photo electric assembly circuit board work now finished black wire connected junction LED LDR leads green wire junction LDRs orange wire remaining LDR lead blue wire anode re maining free end LED See ex planation Fig 5 motor removed pops right out gear train engaged plug servo receiver servooperator Turn power look down through top output shaft should see bright glow LED Though have built unit correctly will still almost certainly completely out adjustment Leave motor out gear box ie installed servo top section top cover place over gears photoelectric assembly Take off case bottom turn power motor should run transmitter off might initial twitch will run continuously until transmitter turned motor does begin run smoke LED does glow have defect construction Unplug servo look solder bridges misplaced parts other things electronics kits caution about unit OK far PRODUCTS FOR TIW n tmau Mf Unflet lete Line Exhaust Systems Tuned Pipes led Tuned Pipes Headers uri Mufflers Expansion Mufflers Helicopter Ball Mufflers ialized Exhaust Systems Unsurpassad Wnk,smnohin F Prftrmanc 140 Model Aviation New Robart RIGHT ANGLE DRIVE Dremel Moto-Tools U motor running turn transmitter motor will likely run direction unless struck lucky will stop reverse move control stick Shut receiver off adjust travel pot R2 extreme right its range looking top point maximum travel will reduce later procedure Make sure both transmitter receiver set servo arm neutral center adjust centering pot R8 point motor either stops oscillates Shut off receiver engage motor gear train Turn receiver back output arm runs side wont come back reverse leads motor start over correct motor connection may result servo arm oscillating though no command has given phenome non should cease travel pot readjusted now set travel pot mid-range arm comes rest point off-center set linearity pot R5 center positioning servo arm Now check 450 travel side center travel control affects total amount travel linearity control affects amount travel side center three controls centering linearity travel interact affects others may necessary go over several times Dont strive perfection making adjustments though because wont get finished servo oscillates IC may sensitive ones requires change 82Kresistor R9 value 68K 56K does oscillate fact seems underpowered change R9 either lOOK 120K changes will require small amount recentering given sudden large amounts stick action under no-load conditions servo will overshoot immediately re turn commanded position due lag response time LDRs confronted sudden large change brightness Since servos modeling environment rarely operate out some kind load would appear no problem Although further development servo might result eliminating two pots would seem 2K centering pot will always need retained can visualize though unit lower part output shaft shadow mask could independently adjustable respect output gear itself would friction adjustment could set top servo just servos now would require some delicate machining Im working Im also process trying adapt photoelectric concept use Signetics NE544 IC have little luck servo operates perfectly itself used other servos kind causes buzz jump oscillate Signetics chip does require additional external transistors does Kraft IC appeal smaller lighter still has experimenting have questions comments please write author George Gibson RR 1 Box 157 Fountain MI 49410 RC Soaring/Blakeslee Continued page 41 AMA did recognize Soaring time contest became bigger single AMA event premier event year event run Dan drew over 200 com petitors over country com petition its finest meet names like Mark Smith Dave Shadel Otto Heithecker Don Edberg Warren Plohr LeMon Payne Col Bob Thacker John Baxter Dave Thornburg Bob Gill Dale Nutter Jeff Mrlik Dwight Holly people flew against another single major contest today Glider pilots travel AMA Nats like did SOAR Nationals Dan Pruss ran class contest participation SOAR Nats reasons Soaring finally added AMA event Thank Dan Pruss will always treasure people experiences because Kurt Rosner fellow Rocky Mountain Soaring Association member favorite bird shot down off-field interference prompted Kurt try find Out what hit him So went out bought frequency scanner found commercial station operating 10 kHz below channel 44 First lets have Kurt describe scanner Regency MX500 may first readily-available new breed communica tions receivercontinuous coverage 25 550 MHz Other receivers give several seg ments bands within range dont give access example RC channels 72 MHz does frequency-synthesized no crystals keyboard-controlled alphanumeric LCD display comes nifty compact package can program 20-channel scanner set up search between two frequencies steps 5 125 25 kHz AM NFM WFM narrow- wide-band FM can selected example might want program up 20 RC channels Scan mode Search 720 730 MHz 5 kHz steps find potentially troublemaking signals lurking between RC channels area MX500 comes plug-in telescoping antenna 120-volt adapter cable install cigarette-lighter plug whatever cars 12-volt battery mounting bracket got CW Electronic Sales Denver $299 recently reduced $415 first hit market $600 Two nega tives instruction book skimpy doesnt cover keyboard-control capabilities unit Second little gem may distract real hobby Its imported Regency Electronics Inc 7707 Records St Indianapolis IN 46226 Kurts second step contact District IX Frequency Coordinator Steve Mangles lives Denver Steve found offender mobile phone service broadcasting data voice signals directionally Denver towards Boulder Kurt got hit Small consolation Kurt can hear signal loud clear new scanner Steve also learned same company L7ZY U L2 2U OOO LYUJLiI9 SEE OUR BACK COVER AD THIS ISSUE tested Maloney 100 first off quarter scale Cap 20L thai weighed about 15 pounds model first flown 23 cdee rich Zenoah G-23 Frar*ly Maloney 100 would get model trp air could loop level flight model under powered moat people standards Robinhood 80s 12 1/2 ounds fly wel i ntly bulit 90 sized Long John again shortened nose came 10 1/2 pounds model complete flaps fiAt symmetrIcal airfoil model seemingly will maneuver asked flaps down lands about Smiles per hour hope builders smaller Long John will get produce thla sIze kit Weve Modeltech develop two airplanes around Maloney 100 engine Jose StIk Dragon Lady Both modele fly great kept light designed Export 7 ch aystem w14 servos Maloney 100 Robinhood SO Modeltech Dragonlady Modeltech Joss Silk except outsIde loop J 10 1/2 pounds Robinhood will outslde loop very well cut nose back Robinhood 80 put firewal about 1 inch windshleld meets fuselage Notce cowied engine photo model uses small servos still fling 1200mAh battery peck fother reason thanspendalotof out Presently retaling Expert 7 channel system four servos NiCads transmitter flight packs charger neck strap frequency flag $33995 moment might lid retailers -both hobby mail order shops sefling thle system low $15000 terrific buy compared what get some ether systems br kind money fear prIce system will probably going si little bit near future because continuing devaluation US Blail $33995 $19995 $8995 $22495 $15995 j2ZJ u IQ GOQ G2ThLD 8960 Rossash Ave Cincinnati Ohio 45236 Phone 513 793-5900 x 214 557 January 1987 141 JeJtatmtlId maximize performance Maloney 100
Edition: Model Aviation - 1987/01
Page Numbers: 36, 37, 38, 39, 137, 138, 140, 141
Photon Servos two parts move against other destined wear out servos use translates feedback pot begins deterio rate time first moves have searched way avoid mechanical weak link now engineer own ranks may have come up photoelectric feedback system built around Dunham mechanics feedback pot housing has removed arrow points out light-dependent resistors ALMOST EVERY RC FLIER knows what feedback pot Some may have learned about hard way culprit behind crash best piloting skills couldnt have prevented causes trouble other part servo supposed necessary evils wed like able Its little carbon-coated vari able resistor servo has taken apart cleaned lubricated often maintenance isnt done servo arm will eventually become erratic jiggling jumping trying run continuously happens can generally kiss model good-bye feedback potentiometer used continuously-variable voltage divider fixed regulated voltage applied across pot wiper rotated servo motor through reduction gearing voltage divided continuously wiper moves its amplitude completely dependent upon position wiper therefore position output arm voltage governs duration reference pulse generated 36 Model Aviation 1 p-- answer EGeorge Gibson CuttheLDR retaining clipfromatin can lid use CyA glue LDRs place servo compared incoming control pulse receiver duration two pulses identical cancel out servo stops Any irregularity carbon surface pot element depending its character will cause malfunctions addition wiper slides over ele ment gradually wears away primarily over center travel tiny bits wiper metal depositedcausing element behave erratically evil weve put up ever since inception digital RC time Kraft Systems tried eliminate problems feedback pot putting variable capacitor refer ence pulse generator un provement system problems its own should know worked about 10000 Heathkit version servo As trend smaller smaller servos variable capacitors can made small approach phased out meantime quality pots increased price evident pots would always periodic maintenance nuisance Carbon button wiper contacts another im provement button popped out wiper arm saw happen re sulting problems could catastrophic late 1 960s John Cline F&M Electronics experimenting differ ent ways produce servo having incorporate feedback pot outcome research what called variable inductance servo see American Aircraft Modeler February 1968 relatively large metal-cased servo 1 1/16 x January 1987 37 Li Left scale drawing shows clip formed secure LDRs Note rim LDR recessed plastic case Right Remove feedback pot body Dremel tool knife Drill hole #2 screw cut notches wires look closely atthe arrow right can seethe LED peeking through shadow mask has cut hollow output shaft arrow left shows snugly clip holds LDRs Adjust shape clip until sure LDRs cannot move 1 x 3 available linear output eight-pin plug Chine stated research tried photoelectric feedback system before development light-emitting diodes LEDs photoelectrics necessarily de pended filament-type light bulb Cline recognized would im practical four counts mechanism would subject total failure warning whenever filament burned out would have little ability withstand typical model vibrations would cause ex cessive battery drain economically impractical Despite its drawbacks felt would work dont know variable inductance servo ever marketed never saw use photoelectric concept John Cline advanced just waiting technology make practical LEDs light-emitting diodes LDRs light-dependent resistors appeared commercial market couple years after went work Heathkit Co assignments evaluate pre-pro duction run Thumb Tac first photoelectric tachometer appear RC market used transistor-sized pho tocell aforementioned LDRs Thumb Tac developed engineer friend Heath successful both technically com mercially earned him advance grade both members Southwest Michigan Whirlwinds RC Club often discussed possibility using LDR Thumb Tac kit variable resistor reference pulse generator would eliminate trouble some wiping mechanical contacts conventional feedback pot prob lem foresaw LDRs have objectionable warm-up characteristic friend designed special IC chip com pensate LDR drift various reasons eventually dropped project Still idea stuck head decided try another approach keep simple Instead using single LDR requiring special IC retained regnlar Kraft IC used two LDRs series replace feedback pot LDRS carefully matched both would vary resistance same amount same direction During warm-up assuming equal illumination voltage junc tion would remain same junction point course would correspond wiper connection eliminated feed back pot make voltage vary such way simulate movement wiper feedback pot illuminating source would moved away neutral position throw light LDR other voltage junction would rise fall according resistor getting light viable choice light source LED Theyre small immune vibration have very economical current drain theres no filament burn out Almost John Clines problems solved simple device built couple servos using Kraft/ Heath mechanics made LED movable back forth between two LDRs proved concept would work making light source movable required either sliding contacts flexible leads knew inevitably would break cause catastrophic failure both light source light detector stationary moveable mask would have rigged between such way mask moved way other would partially cover uncover LDRs get same effect moving light source would eliminate sliding contacts flexing leads sitting just staring some servo parts constructive idea head suddenly great brainstorm blew through between ears chose servo output gear output shaft might have room gearbox underneath output gear shadow mask knew Dunhams R&R made servo #2 gear located over motor instead under output gear Kraft Heath did ordered four hadnt specified color received white proved problem allowed extraneous light leak onto LDRs tried painting cases black paint worked time flaked off easily Thereafter ordered black cases first successful shadow mask made anodized aluminum glued output shaft required two LEDs although would have increased current drain LEDs series could have simpler Another minor brainstorm resulted putting single LED inside output shaft carving hole side shaft illuminate LDRS As shaft rotated first LDR other would favored light would have effect similar moving light source insert LED bottom end hollow shaft remove short splined shaft attaches pot wiper As brass slug would dis carded along wiper needed devise another way center servo wanted make linearity travel centering adjustable least first few experimental versions O needed second circuit board carry three trimmer pots 50-cent type well some additional resistors capacitors Since no longer needed feedback pot way decided carve off down bottom case make room extra board its parts gave lots room electronics compartment built some ser vos two decks board above other parallel found difficult circuit testing replace parts regrouped ended up two boards mounted right angles mechanics electronics combined oriented shown fit inside servo case gear case cover put first travel adjustments done everything installed case layout has worked out OK far feel production two pots perhaps threecould eliminated single-board electronics would result Replacing troublesome failure-prone feedback pot wasnt simple hoped has definitely worth test-flew three-pot version described over period three years save linkage adjustment set main tenance-free Performance superior hadnt receiver failure causing fatal case fly-away-itis Id flying yet plan patent photon servo Im publicizing notion someone will develop further Adjustments both Kraft Heath servos feedback pot located collector reference pulse generator Its IC its still made up transis tors first substituted LDRs same position travel linearity good tried LDR double base circuit linearity still good Finally put diode base circuit reverse-biased would isolated except base driven neg ative cutoff pulse linearity 38 Model Aviation rough prototype set circuit boards shows perpendicular board layout electronics section vertical board Cir cuit Board #1 available Heathkit other constructed per text better could adjusted 10K pot connected across two LDRs wiper arm attached LDR junc tion Early project found LDR used Thumb Tac suitable servo use since high-resistance type contacted Clairol manufacturer found producing LDRS resistance ranges supplied performance data ordered 10 lowest-resistance range set up test jig Surprise resistance under identical test conditions varied much 300% batch 10 two nearly identical enough servo rest could matched up ordered another 100 got enough matches 29 servos dont have same value just have matched pairs Naturally choices available matches As no longer mechanical feedback pot need alternative method adjust servos centering replaced 1K load resistor collector circuit reference pulse generator inexpensive 2K pot small variation light intensity LDRs will result relatively large change voltage junctionmuch equivalent rotation feed back pot Resistors R2 R3 R4 form network attenuate voltage output arm can rotate farther before control voltage reaches value will result stop Resistor R2 also trimmer pot used adjust length servo travel some later versions mounted LDRs simply gluing place cyanoacrylate CyA units immediately began experience high fail ure rates though two earlier versions LDRs held untidily place wire clips still worked fine Out curiosity added CyA servos next day failed also assume CyA caused failures although dont know Mounting now done sheetmetal clips made top dog food can see pattern have no failures photon servo will draw current standard servo willbut sig nificantly neutral two LDRs will draw maximum about 3 mA LED about 5 mA comparison feedback pot draws 13 mA consider servos typically draw about 20 mA idle least 150 mA under load extra 4 mA insignificant over three years testing have never experienced battery-drain problems schematic parts marked * already installed original circuit board Heath part #238-95 will have make #2 circuit board simple have used three methods con struction Cut-and-peel copper foil very thin PC board material conventional etching non-foil perforated board using bent-over component leads interconnections As two PC boards will assembled 900 other board #2 must notched fit end several sizes 4-watt re sistors market sure get smallest size go -watt com ponents circuit draw enough current get warm trimmer pots used Digi-Key Corp enclosed sealed against dust As 6mm pots take up room #2 board resistors capacitor must carefully located interfere access diagrams should help avoid trouble Also since pots adjustable both top bottom can drill -in holes board pots can set non-component side should first attempt building servo youve successfully assembled kit servos should have little difficulty After boards Heath Some components will left off Heath board incorporated second others will change value type have Heath board already built up can use making necessary modifications Construction After trying servomechan isms several manufacturers decided Dunham D-1 particularly suited purpose has gear arrangement required plus hollow output shaft can modified use shadow-mask gears are of nylon filled Continued page 137 January1987 39 LORs non-polarized either end can connected B LEDs polarized will glow leads reversed Although shown fiat two boards will mounted right angles Note interconnections between two boards LED LDRs q1~ WEIGHT-MATES HEAVY DUTY FABRIC WEIGHT BAGS FOR BUILDING TRANSPORTING & FIELD TIE-DOWN Easily filled w/sand shot up 5 Ibs Five 4x6 bags per package Conforms curvatures Complete instructions $695 postage & handling AZ residents add 35X tas Radio Technique/Myers Continued page 133 transmitter receiver few AM FM sets already conform guidelines So can expect early part 1988 will see low band occupied some pretty good stuff will up keep way vigorously persuading rebels mend ways having equipment serviced periodically keep operating should Based transmitter tests performed three Nats three trade shows seems some AM FM transmitter designs can quali fied slight modifications same informa tion makes seem highly unlikely transmit ters now old channels BN/W through GN/W will ever qualified just basis costs involved Receivers another matter Very few exist ing receivers qualify except Kraft -8FD -8FDS dual-conversion PCM receivers like Simprop PCM-20 Multiplex time gets print expect other qualified receivers will put circula tion Ace R/C Airtronics Circus Futaba others will have own shopping leave reviewing business friend Bob Aberle does very well read Flying Models magazine dont already George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Photon Servos/Gibson Continued page 39 material glass fiber makes very sturdy Dunham guarantees free replace ment part fails reason including crash damage small lots sell approximately $7 lots 100 little over $2 Re member specify black cases order Disassemble servo com pletely careful lose parts particularly small gear pins output gear attached wiper rotor splined brass shaft extends 1GRATE-SHAPES SANDING BLOCKS GS 101 3/u XG5103 K G 5 105 &3k 90Vsw/% X GS 102 /o & m GS 0 %&wR Grit sides Always consistantly rounded edges Long-lasting silicon carbide grit Combo Package 101 102 & 103or specify three $1195 P & H AZ residents add 60 ta Single GRATE-SHAPES $495 P & H AZ residents add 255 tas products guaranteedDealers invited SEND cHECK OR---MONEY ORDER TO Bell Rock Industries Hwy 179-Suite 108 Sedona AZ 86336 284-1808 through bottom gear case Care fully pull upward gear will require some force will separate brass shaft will using shaft wiper project use method want separating damage bearing hole Unless old string saver discard shaft wiper feedback pot body molded integral part servo center section gear case bottom may split several segments can sawed off individually See Fig 4 use Moto Tool cutoff wheel carve stumps flush sharp knife Make two t/ie-in slots Moto cutoff tool drill hole clear #2 screw Now select red LED will fit bottom end output gear shaft LED should wide-angled should fit snugly turn freely flange LED must also sanded off allow inserted deep enough inside shaft Assemble output gear servo top section place LED leads extending down through bearing hole Pull LED down firmly grasping leads put droportwoof5-min epoxy bearing hole around leads use CyA anywhere else servo Let epoxy set firmly before proceeding further remove top section output gear retaining clip two LDRs made top tin can Spring brass bronze could also used dont recommend aluminum case must thin strong Dimensions details given Figs 2 & 3 LDRs will lay flat sides have rim prevents attempt grind flat spot rim though will destroy hermetic seal Instead use defunct metal-cased transis tor same size LED mount place retaining clip heat rim soldering iron until plastic melts E -% BOOSTER Space Age Charging Has Arnvedl Convenient solar charging will solve battery charging problems flying sight boosting batteries between flights Safe 100 MA Charge Rate Autumatic Cat-OS Full Charge High Efficiency Under Cloudy Cosditioou Charges-Both RX asd TX Simultaneously Popular Radio Systems Using 48 96 Volts Handy Plug-In Charging Cord Adjustable Angle Bracket Bailt Everyday Use RaggedLightweighl Easy Curry Handle Full Warranty $7995 Introductory Dtter $450 Shipping & Handling USA AZ Residents Add $400 Tax allows rim sink surface too much heat youll ruin plastic case recess melted case LDRs can now made set flat held place retaining clip Mount shown Fig 5 bending bottom lead LDR downward through Yt6-in slots other lead LDR will bent forward two joined can soldered retaining clip desired junction green wire board #2 will later soldered removing flange LED during its installation also removed flat flange identifies cathode lead install diode properly must re-identify lead connect two wires positive negative outputs flight battery solder 1000-ohm resistor end positive lead Touch negative wire LED lead free end 1K resistor other lead LED does light reverse connections LED lights lead going 1K resistor anode other lead cathode Bend cathode lead over flat solder lead LDR2 comes through slot Later black wire board #2 will connected also Now shadow mask Look bottom side output gear neutral point raised ridge about e-in wide radiating shaft out ward rim Take sharp point scribe line shaft center ridge downward bottom end shaft parallel its axis point line om end make tiny punch mark drill hole through shaft wall Enlarge hole /u6-in drill %2-in drill Dont drill through both sides shaft though Square up hole sharp X-Acto blade shadow mask complete January 1987 137 DGADelignsss OGA Designs DGA Designs. DGA Designs es DGA Designs o5 S *DARNED GOOD AIRMEN Lightest weight Pilots Available Ia0 * FULL BODY PILOT KIT e ke Vny e abbe pa-ts Easy assenble finish Kit contains Pilot head hands boots heintet5 Ocap goggles full tentplates easy inett-ttctiOns Fully positionable too0 Height- Weight-NEW LOW Pttces-5 NO206 .1/6 Scale lls 2 oz s72 rJ\rK NO206 5 Scale 14 3oz s89 No204-1/4 Scale 174 ozs 99501 V[7V kJO 203 13 Scale 236ozsI6 100 55PORT5MAN o BARNSTORMER- FULL RODS Oo RUSTfl/C C *s4J5 PILOT KIT LitSike 0OV lOthS 055t, pad,0 Ktt csntates PAst head hornet spod cap gossips OJacket. Easy asoornitie aho tjhsh Height WeightLOW Peicee5 ,No1O9t OScaip310Otoa5 59/5 4 No tOO t SRCOieO8tI 400sd%hc NO 04- aScaleadottao7Sh*sOme01 No tOg t iScale5-34240sl4~ simple tOsewtng5 Astounding htOliOeqt4irea0 4 attainable plastics.. ODoe tothete5temeti9et Weight Oat trntpiotcatoii ooa5o idiOt 0boOtS WiicaoeitttieothoettoctohthetaihctOtVootaiCatt 0 Send slOO Catalog SI Ne YOtt state RoOdoots add 75 sales tOO. Send Check ot- MO. cO Os Ai Oss 3 seeks cseck toctear 5 s DGA Designs 5 5 DGA 55 OGA Designs Reassembling gear train takes little sleight hand Put servo top section top cover separate Dunham D-l As top cover will remain place unassisted until case bottom can fastened wrap some tape around assembly retain cover no light can get Shorten remaining free lead CL-2 LATCH FOR COAL ItATCtI CAGtOPY & tdIttO AINPIN 2-STAGE PRESSURE STAG MORE GOODIES CANOPY TRACK AIRPIN PRESS GUAGE CUSTOM Ant CYLINDERS PROPHUT/SPINHER ATTACH EXT PROPEUTS FUR P-It PItU ete &IE OPERATES LATCH tTLAS Oev F2tGfltES STItoNGI ltD TIMER KITS SEND SASE FOR INFO DEALER INQUIRIES INVITED PHORE3O 73161 ROBINAIR E P 0 80X8770 CORAL SPRINGS FLORIDA33O75 MINICYLINDERS LED anode make soldering loop will later attach blue wire coming board #1 install motor point Rotate gears output gear neutral put output arm onto shaft neutral also Leave out arm retaining screw servo completed power should see bright red glow LED look down through top shaft Circuit board assembly As mentioned before circuit board #1 actually Heathkit part #238-95 using pre assembled board Heath servo leave following parts board power transistors motor leads servo con necting cable plug 1 0sF tantalum capacitor some units 22F 47F tantalum capacitor 001/LF ceramic capacitor IC Remove other parts Clip parts off above board try salvage Cut off flush top surface board will now very easy unsolder remaining stumps shake off board ruining foils process starting new board mount IC first being sure correctly oriented foil pad very narrow extends around three edges board 48-volt foil notched indented end IC will go middle section foil #1 pin will connect foil directly have provided diagram foil pattern copyrighted have identified holes use lettering top view board Fig 6 Assuming using red white black green color-coded servo connecting cable Heath has always used connect red wire hole marked B nearest pin #1 IC cases told connect wire component solder joint though another connection made later point system uses different color code youre own Connect black wire cable hole W also marked B- Connect green wire hole N nearest IC pin #12 cable has white wire clip plug strip out cable Use later needed Install two MPS6562 transistors leads marked transistor body EBC must go hole labeled corresponding letter see diagram sure leads short enough transistor does stand above board Install 47MF tantalum capacitor plus lead going hole T minus lead through hole U can use metal-cased type Heath used used dipped tantalum because fits better precision capacitor re quired Install OO1tF 1000 pF capacitor holes R S Heath used tubular unit used tiny disc capacitor Digi-Key just fits Again precision point required Install lOOK resistor RiO body standing up vertically hole X top lead bent over sharply enter hole Y 1 0MF 22FF dipped tantalum capacitor also destined holes X Y will installed later Install 82K resistor holes K L may necessary change value resistor depending servo operates place 22tF capacitor originally used holes F H install 1N914 diode F unbanded end down board left standing vertically later insertion #2 board Lay #1 board aside Prepare #2 board check shorts Borrow ohmmeter have set R x 1000 Touch meter lead foil pads touch other lead successively foil pad bordering first meter does deflect move another foil pad test its neighboring pads same man ner two foils produce indication short use X-Acto knife cut dividing lines deeper remove short sure absolutely no shorts between two foil pads proceed installation electronic components Install two 10K trimpots proper places non-foil side board should stand about %2-in high no Install R6 220K lies along left side board Position body resistor installed will act insulator against bare lead R3 Install two short bits bare wire holes opposite sides clearance notch end board Continued page 140 138 Model Aviation 45 m GEAR MECHANICS FOR BIGGIES Now Can Drill Grind Cut Sand Polish IN PLACES YOU NE VER COULD BEFORE FiRST TIME AVAILABLE great new precision tool has tough ABS housing hardened metal gears Iltetime lubricated bearings Attaches seconds Dremei Moto-Tool models #270 #280 #370 #380 Sears Craftsman rotary tools MUST FOR THE SMALL TOOL WORK SHOP R NOW AND SAVE Use thin onu~ send name addresn payment MICROUARKS Box 5112-3l3eCllnton NJ 08808 E Send n, 'a YES Send ______ RIGHT ANGLE DRIVES Item #50353 24-HOUR CREDIT CARD PI4ONEt 1400-225-1066 $1700 plus $200 shipphig andemtand dl am mm- lEt NJ 201-4644764 pletely satisfied may retum order en immediate refund NAME_______________________________ [ICheclr enclesed NJ residettla add 6% nolan tan [Charge [I VISA [I MaulerCard []AMEX ADDRESS___________________________________ Aoct#_____________________ [I Ship order C 00 $200 additionalCIlYSTATE______ ZIP ______ will connect #2 ground foil #1 ground B other will connect #2 22-volt B foil 22-volt pin IC Install R3 2200 ohms stand ver tically bend bare lead necessary go under R6 Install R4 2200 ohms flat board laid down Install R7 lOOK position shown Install C6 22tF dipped tantalum short negative lead board Leave positive lead long can connected board #1 later Cut 1-in length stranded orange wire Bare end twist strands together before soldering make insertion circuit board holes easier Connect end circuit foil board #2 shown Cut 2-in lengths blue black green orange wire prepare described previously 1-in stranded wire Connect blue wire top ofRi board #1 green black orange wires board #2 shown top Fig 5 Mount board #2 proper end board #1 components of#2 will overhang of# 1 short bits ofbare wire previously soldered lower end #2 should now bent downward fit vacant holes board #1 boards should form right angle notch board #2 should fit over end IC flush end Feed entire length positive lead 1 N9 14 diode through hole X board #2 Cover lead Teflon tubing bend over connect foil pad same place bare lead R7 connected Solder clip off excess lead Install lMF polyester capacitor Cl holes X andY lead goes through same hole used 1N914 diode Solder diode lead clip off excess wire leads must belong enough capacitor straddles top R3 Bend lead going through hole Y solder wiper terminal pot R8 Connect free end 1-in orange wire hole H shown Fig 6 other wires black green blue orange go LED-LDR photoelectric assembly gear case compartment Terminals assembly brought through gear case bottom feedback pot body removed Cut two pieces wire brown other white length 1 in, prepare ends before Put brown wire through hole M white wire through hole AZ Connect other ends wires motor follows white red positive terminal brown other terminal Connect CS 05F cer amic disc across motor terminals leads CS should left long enough extend down sides motor out way lead going red terminal must insulated other lead can left bare must grounded case Except connections photo electric assembly circuit board work now finished black wire connected junction LED LDR leads green wire junction LDRs orange wire remaining LDR lead blue wire anode re maining free end LED See ex planation Fig 5 motor removed pops right out gear train engaged plug servo receiver servooperator Turn power look down through top output shaft should see bright glow LED Though have built unit correctly will still almost certainly completely out adjustment Leave motor out gear box ie installed servo top section top cover place over gears photoelectric assembly Take off case bottom turn power motor should run transmitter off might initial twitch will run continuously until transmitter turned motor does begin run smoke LED does glow have defect construction Unplug servo look solder bridges misplaced parts other things electronics kits caution about unit OK far PRODUCTS FOR TIW n tmau Mf Unflet lete Line Exhaust Systems Tuned Pipes led Tuned Pipes Headers uri Mufflers Expansion Mufflers Helicopter Ball Mufflers ialized Exhaust Systems Unsurpassad Wnk,smnohin F Prftrmanc 140 Model Aviation New Robart RIGHT ANGLE DRIVE Dremel Moto-Tools U motor running turn transmitter motor will likely run direction unless struck lucky will stop reverse move control stick Shut receiver off adjust travel pot R2 extreme right its range looking top point maximum travel will reduce later procedure Make sure both transmitter receiver set servo arm neutral center adjust centering pot R8 point motor either stops oscillates Shut off receiver engage motor gear train Turn receiver back output arm runs side wont come back reverse leads motor start over correct motor connection may result servo arm oscillating though no command has given phenome non should cease travel pot readjusted now set travel pot mid-range arm comes rest point off-center set linearity pot R5 center positioning servo arm Now check 450 travel side center travel control affects total amount travel linearity control affects amount travel side center three controls centering linearity travel interact affects others may necessary go over several times Dont strive perfection making adjustments though because wont get finished servo oscillates IC may sensitive ones requires change 82Kresistor R9 value 68K 56K does oscillate fact seems underpowered change R9 either lOOK 120K changes will require small amount recentering given sudden large amounts stick action under no-load conditions servo will overshoot immediately re turn commanded position due lag response time LDRs confronted sudden large change brightness Since servos modeling environment rarely operate out some kind load would appear no problem Although further development servo might result eliminating two pots would seem 2K centering pot will always need retained can visualize though unit lower part output shaft shadow mask could independently adjustable respect output gear itself would friction adjustment could set top servo just servos now would require some delicate machining Im working Im also process trying adapt photoelectric concept use Signetics NE544 IC have little luck servo operates perfectly itself used other servos kind causes buzz jump oscillate Signetics chip does require additional external transistors does Kraft IC appeal smaller lighter still has experimenting have questions comments please write author George Gibson RR 1 Box 157 Fountain MI 49410 RC Soaring/Blakeslee Continued page 41 AMA did recognize Soaring time contest became bigger single AMA event premier event year event run Dan drew over 200 com petitors over country com petition its finest meet names like Mark Smith Dave Shadel Otto Heithecker Don Edberg Warren Plohr LeMon Payne Col Bob Thacker John Baxter Dave Thornburg Bob Gill Dale Nutter Jeff Mrlik Dwight Holly people flew against another single major contest today Glider pilots travel AMA Nats like did SOAR Nationals Dan Pruss ran class contest participation SOAR Nats reasons Soaring finally added AMA event Thank Dan Pruss will always treasure people experiences because Kurt Rosner fellow Rocky Mountain Soaring Association member favorite bird shot down off-field interference prompted Kurt try find Out what hit him So went out bought frequency scanner found commercial station operating 10 kHz below channel 44 First lets have Kurt describe scanner Regency MX500 may first readily-available new breed communica tions receivercontinuous coverage 25 550 MHz Other receivers give several seg ments bands within range dont give access example RC channels 72 MHz does frequency-synthesized no crystals keyboard-controlled alphanumeric LCD display comes nifty compact package can program 20-channel scanner set up search between two frequencies steps 5 125 25 kHz AM NFM WFM narrow- wide-band FM can selected example might want program up 20 RC channels Scan mode Search 720 730 MHz 5 kHz steps find potentially troublemaking signals lurking between RC channels area MX500 comes plug-in telescoping antenna 120-volt adapter cable install cigarette-lighter plug whatever cars 12-volt battery mounting bracket got CW Electronic Sales Denver $299 recently reduced $415 first hit market $600 Two nega tives instruction book skimpy doesnt cover keyboard-control capabilities unit Second little gem may distract real hobby Its imported Regency Electronics Inc 7707 Records St Indianapolis IN 46226 Kurts second step contact District IX Frequency Coordinator Steve Mangles lives Denver Steve found offender mobile phone service broadcasting data voice signals directionally Denver towards Boulder Kurt got hit Small consolation Kurt can hear signal loud clear new scanner Steve also learned same company L7ZY U L2 2U OOO LYUJLiI9 SEE OUR BACK COVER AD THIS ISSUE tested Maloney 100 first off quarter scale Cap 20L thai weighed about 15 pounds model first flown 23 cdee rich Zenoah G-23 Frar*ly Maloney 100 would get model trp air could loop level flight model under powered moat people standards Robinhood 80s 12 1/2 ounds fly wel i ntly bulit 90 sized Long John again shortened nose came 10 1/2 pounds model complete flaps fiAt symmetrIcal airfoil model seemingly will maneuver asked flaps down lands about Smiles per hour hope builders smaller Long John will get produce thla sIze kit Weve Modeltech develop two airplanes around Maloney 100 engine Jose StIk Dragon Lady Both modele fly great kept light designed Export 7 ch aystem w14 servos Maloney 100 Robinhood SO Modeltech Dragonlady Modeltech Joss Silk except outsIde loop J 10 1/2 pounds Robinhood will outslde loop very well cut nose back Robinhood 80 put firewal about 1 inch windshleld meets fuselage Notce cowied engine photo model uses small servos still fling 1200mAh battery peck fother reason thanspendalotof out Presently retaling Expert 7 channel system four servos NiCads transmitter flight packs charger neck strap frequency flag $33995 moment might lid retailers -both hobby mail order shops sefling thle system low $15000 terrific buy compared what get some ether systems br kind money fear prIce system will probably going si little bit near future because continuing devaluation US Blail $33995 $19995 $8995 $22495 $15995 j2ZJ u IQ GOQ G2ThLD 8960 Rossash Ave Cincinnati Ohio 45236 Phone 513 793-5900 x 214 557 January 1987 141 JeJtatmtlId maximize performance Maloney 100
Edition: Model Aviation - 1987/01
Page Numbers: 36, 37, 38, 39, 137, 138, 140, 141
Photon Servos two parts move against other destined wear out servos use translates feedback pot begins deterio rate time first moves have searched way avoid mechanical weak link now engineer own ranks may have come up photoelectric feedback system built around Dunham mechanics feedback pot housing has removed arrow points out light-dependent resistors ALMOST EVERY RC FLIER knows what feedback pot Some may have learned about hard way culprit behind crash best piloting skills couldnt have prevented causes trouble other part servo supposed necessary evils wed like able Its little carbon-coated vari able resistor servo has taken apart cleaned lubricated often maintenance isnt done servo arm will eventually become erratic jiggling jumping trying run continuously happens can generally kiss model good-bye feedback potentiometer used continuously-variable voltage divider fixed regulated voltage applied across pot wiper rotated servo motor through reduction gearing voltage divided continuously wiper moves its amplitude completely dependent upon position wiper therefore position output arm voltage governs duration reference pulse generated 36 Model Aviation 1 p-- answer EGeorge Gibson CuttheLDR retaining clipfromatin can lid use CyA glue LDRs place servo compared incoming control pulse receiver duration two pulses identical cancel out servo stops Any irregularity carbon surface pot element depending its character will cause malfunctions addition wiper slides over ele ment gradually wears away primarily over center travel tiny bits wiper metal depositedcausing element behave erratically evil weve put up ever since inception digital RC time Kraft Systems tried eliminate problems feedback pot putting variable capacitor refer ence pulse generator un provement system problems its own should know worked about 10000 Heathkit version servo As trend smaller smaller servos variable capacitors can made small approach phased out meantime quality pots increased price evident pots would always periodic maintenance nuisance Carbon button wiper contacts another im provement button popped out wiper arm saw happen re sulting problems could catastrophic late 1 960s John Cline F&M Electronics experimenting differ ent ways produce servo having incorporate feedback pot outcome research what called variable inductance servo see American Aircraft Modeler February 1968 relatively large metal-cased servo 1 1/16 x January 1987 37 Li Left scale drawing shows clip formed secure LDRs Note rim LDR recessed plastic case Right Remove feedback pot body Dremel tool knife Drill hole #2 screw cut notches wires look closely atthe arrow right can seethe LED peeking through shadow mask has cut hollow output shaft arrow left shows snugly clip holds LDRs Adjust shape clip until sure LDRs cannot move 1 x 3 available linear output eight-pin plug Chine stated research tried photoelectric feedback system before development light-emitting diodes LEDs photoelectrics necessarily de pended filament-type light bulb Cline recognized would im practical four counts mechanism would subject total failure warning whenever filament burned out would have little ability withstand typical model vibrations would cause ex cessive battery drain economically impractical Despite its drawbacks felt would work dont know variable inductance servo ever marketed never saw use photoelectric concept John Cline advanced just waiting technology make practical LEDs light-emitting diodes LDRs light-dependent resistors appeared commercial market couple years after went work Heathkit Co assignments evaluate pre-pro duction run Thumb Tac first photoelectric tachometer appear RC market used transistor-sized pho tocell aforementioned LDRs Thumb Tac developed engineer friend Heath successful both technically com mercially earned him advance grade both members Southwest Michigan Whirlwinds RC Club often discussed possibility using LDR Thumb Tac kit variable resistor reference pulse generator would eliminate trouble some wiping mechanical contacts conventional feedback pot prob lem foresaw LDRs have objectionable warm-up characteristic friend designed special IC chip com pensate LDR drift various reasons eventually dropped project Still idea stuck head decided try another approach keep simple Instead using single LDR requiring special IC retained regnlar Kraft IC used two LDRs series replace feedback pot LDRS carefully matched both would vary resistance same amount same direction During warm-up assuming equal illumination voltage junc tion would remain same junction point course would correspond wiper connection eliminated feed back pot make voltage vary such way simulate movement wiper feedback pot illuminating source would moved away neutral position throw light LDR other voltage junction would rise fall according resistor getting light viable choice light source LED Theyre small immune vibration have very economical current drain theres no filament burn out Almost John Clines problems solved simple device built couple servos using Kraft/ Heath mechanics made LED movable back forth between two LDRs proved concept would work making light source movable required either sliding contacts flexible leads knew inevitably would break cause catastrophic failure both light source light detector stationary moveable mask would have rigged between such way mask moved way other would partially cover uncover LDRs get same effect moving light source would eliminate sliding contacts flexing leads sitting just staring some servo parts constructive idea head suddenly great brainstorm blew through between ears chose servo output gear output shaft might have room gearbox underneath output gear shadow mask knew Dunhams R&R made servo #2 gear located over motor instead under output gear Kraft Heath did ordered four hadnt specified color received white proved problem allowed extraneous light leak onto LDRs tried painting cases black paint worked time flaked off easily Thereafter ordered black cases first successful shadow mask made anodized aluminum glued output shaft required two LEDs although would have increased current drain LEDs series could have simpler Another minor brainstorm resulted putting single LED inside output shaft carving hole side shaft illuminate LDRS As shaft rotated first LDR other would favored light would have effect similar moving light source insert LED bottom end hollow shaft remove short splined shaft attaches pot wiper As brass slug would dis carded along wiper needed devise another way center servo wanted make linearity travel centering adjustable least first few experimental versions O needed second circuit board carry three trimmer pots 50-cent type well some additional resistors capacitors Since no longer needed feedback pot way decided carve off down bottom case make room extra board its parts gave lots room electronics compartment built some ser vos two decks board above other parallel found difficult circuit testing replace parts regrouped ended up two boards mounted right angles mechanics electronics combined oriented shown fit inside servo case gear case cover put first travel adjustments done everything installed case layout has worked out OK far feel production two pots perhaps threecould eliminated single-board electronics would result Replacing troublesome failure-prone feedback pot wasnt simple hoped has definitely worth test-flew three-pot version described over period three years save linkage adjustment set main tenance-free Performance superior hadnt receiver failure causing fatal case fly-away-itis Id flying yet plan patent photon servo Im publicizing notion someone will develop further Adjustments both Kraft Heath servos feedback pot located collector reference pulse generator Its IC its still made up transis tors first substituted LDRs same position travel linearity good tried LDR double base circuit linearity still good Finally put diode base circuit reverse-biased would isolated except base driven neg ative cutoff pulse linearity 38 Model Aviation rough prototype set circuit boards shows perpendicular board layout electronics section vertical board Cir cuit Board #1 available Heathkit other constructed per text better could adjusted 10K pot connected across two LDRs wiper arm attached LDR junc tion Early project found LDR used Thumb Tac suitable servo use since high-resistance type contacted Clairol manufacturer found producing LDRS resistance ranges supplied performance data ordered 10 lowest-resistance range set up test jig Surprise resistance under identical test conditions varied much 300% batch 10 two nearly identical enough servo rest could matched up ordered another 100 got enough matches 29 servos dont have same value just have matched pairs Naturally choices available matches As no longer mechanical feedback pot need alternative method adjust servos centering replaced 1K load resistor collector circuit reference pulse generator inexpensive 2K pot small variation light intensity LDRs will result relatively large change voltage junctionmuch equivalent rotation feed back pot Resistors R2 R3 R4 form network attenuate voltage output arm can rotate farther before control voltage reaches value will result stop Resistor R2 also trimmer pot used adjust length servo travel some later versions mounted LDRs simply gluing place cyanoacrylate CyA units immediately began experience high fail ure rates though two earlier versions LDRs held untidily place wire clips still worked fine Out curiosity added CyA servos next day failed also assume CyA caused failures although dont know Mounting now done sheetmetal clips made top dog food can see pattern have no failures photon servo will draw current standard servo willbut sig nificantly neutral two LDRs will draw maximum about 3 mA LED about 5 mA comparison feedback pot draws 13 mA consider servos typically draw about 20 mA idle least 150 mA under load extra 4 mA insignificant over three years testing have never experienced battery-drain problems schematic parts marked * already installed original circuit board Heath part #238-95 will have make #2 circuit board simple have used three methods con struction Cut-and-peel copper foil very thin PC board material conventional etching non-foil perforated board using bent-over component leads interconnections As two PC boards will assembled 900 other board #2 must notched fit end several sizes 4-watt re sistors market sure get smallest size go -watt com ponents circuit draw enough current get warm trimmer pots used Digi-Key Corp enclosed sealed against dust As 6mm pots take up room #2 board resistors capacitor must carefully located interfere access diagrams should help avoid trouble Also since pots adjustable both top bottom can drill -in holes board pots can set non-component side should first attempt building servo youve successfully assembled kit servos should have little difficulty After boards Heath Some components will left off Heath board incorporated second others will change value type have Heath board already built up can use making necessary modifications Construction After trying servomechan isms several manufacturers decided Dunham D-1 particularly suited purpose has gear arrangement required plus hollow output shaft can modified use shadow-mask gears are of nylon filled Continued page 137 January1987 39 LORs non-polarized either end can connected B LEDs polarized will glow leads reversed Although shown fiat two boards will mounted right angles Note interconnections between two boards LED LDRs q1~ WEIGHT-MATES HEAVY DUTY FABRIC WEIGHT BAGS FOR BUILDING TRANSPORTING & FIELD TIE-DOWN Easily filled w/sand shot up 5 Ibs Five 4x6 bags per package Conforms curvatures Complete instructions $695 postage & handling AZ residents add 35X tas Radio Technique/Myers Continued page 133 transmitter receiver few AM FM sets already conform guidelines So can expect early part 1988 will see low band occupied some pretty good stuff will up keep way vigorously persuading rebels mend ways having equipment serviced periodically keep operating should Based transmitter tests performed three Nats three trade shows seems some AM FM transmitter designs can quali fied slight modifications same informa tion makes seem highly unlikely transmit ters now old channels BN/W through GN/W will ever qualified just basis costs involved Receivers another matter Very few exist ing receivers qualify except Kraft -8FD -8FDS dual-conversion PCM receivers like Simprop PCM-20 Multiplex time gets print expect other qualified receivers will put circula tion Ace R/C Airtronics Circus Futaba others will have own shopping leave reviewing business friend Bob Aberle does very well read Flying Models magazine dont already George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Photon Servos/Gibson Continued page 39 material glass fiber makes very sturdy Dunham guarantees free replace ment part fails reason including crash damage small lots sell approximately $7 lots 100 little over $2 Re member specify black cases order Disassemble servo com pletely careful lose parts particularly small gear pins output gear attached wiper rotor splined brass shaft extends 1GRATE-SHAPES SANDING BLOCKS GS 101 3/u XG5103 K G 5 105 &3k 90Vsw/% X GS 102 /o & m GS 0 %&wR Grit sides Always consistantly rounded edges Long-lasting silicon carbide grit Combo Package 101 102 & 103or specify three $1195 P & H AZ residents add 60 ta Single GRATE-SHAPES $495 P & H AZ residents add 255 tas products guaranteedDealers invited SEND cHECK OR---MONEY ORDER TO Bell Rock Industries Hwy 179-Suite 108 Sedona AZ 86336 284-1808 through bottom gear case Care fully pull upward gear will require some force will separate brass shaft will using shaft wiper project use method want separating damage bearing hole Unless old string saver discard shaft wiper feedback pot body molded integral part servo center section gear case bottom may split several segments can sawed off individually See Fig 4 use Moto Tool cutoff wheel carve stumps flush sharp knife Make two t/ie-in slots Moto cutoff tool drill hole clear #2 screw Now select red LED will fit bottom end output gear shaft LED should wide-angled should fit snugly turn freely flange LED must also sanded off allow inserted deep enough inside shaft Assemble output gear servo top section place LED leads extending down through bearing hole Pull LED down firmly grasping leads put droportwoof5-min epoxy bearing hole around leads use CyA anywhere else servo Let epoxy set firmly before proceeding further remove top section output gear retaining clip two LDRs made top tin can Spring brass bronze could also used dont recommend aluminum case must thin strong Dimensions details given Figs 2 & 3 LDRs will lay flat sides have rim prevents attempt grind flat spot rim though will destroy hermetic seal Instead use defunct metal-cased transis tor same size LED mount place retaining clip heat rim soldering iron until plastic melts E -% BOOSTER Space Age Charging Has Arnvedl Convenient solar charging will solve battery charging problems flying sight boosting batteries between flights Safe 100 MA Charge Rate Autumatic Cat-OS Full Charge High Efficiency Under Cloudy Cosditioou Charges-Both RX asd TX Simultaneously Popular Radio Systems Using 48 96 Volts Handy Plug-In Charging Cord Adjustable Angle Bracket Bailt Everyday Use RaggedLightweighl Easy Curry Handle Full Warranty $7995 Introductory Dtter $450 Shipping & Handling USA AZ Residents Add $400 Tax allows rim sink surface too much heat youll ruin plastic case recess melted case LDRs can now made set flat held place retaining clip Mount shown Fig 5 bending bottom lead LDR downward through Yt6-in slots other lead LDR will bent forward two joined can soldered retaining clip desired junction green wire board #2 will later soldered removing flange LED during its installation also removed flat flange identifies cathode lead install diode properly must re-identify lead connect two wires positive negative outputs flight battery solder 1000-ohm resistor end positive lead Touch negative wire LED lead free end 1K resistor other lead LED does light reverse connections LED lights lead going 1K resistor anode other lead cathode Bend cathode lead over flat solder lead LDR2 comes through slot Later black wire board #2 will connected also Now shadow mask Look bottom side output gear neutral point raised ridge about e-in wide radiating shaft out ward rim Take sharp point scribe line shaft center ridge downward bottom end shaft parallel its axis point line om end make tiny punch mark drill hole through shaft wall Enlarge hole /u6-in drill %2-in drill Dont drill through both sides shaft though Square up hole sharp X-Acto blade shadow mask complete January 1987 137 DGADelignsss OGA Designs DGA Designs. DGA Designs es DGA Designs o5 S *DARNED GOOD AIRMEN Lightest weight Pilots Available Ia0 * FULL BODY PILOT KIT e ke Vny e abbe pa-ts Easy assenble finish Kit contains Pilot head hands boots heintet5 Ocap goggles full tentplates easy inett-ttctiOns Fully positionable too0 Height- Weight-NEW LOW Pttces-5 NO206 .1/6 Scale lls 2 oz s72 rJ\rK NO206 5 Scale 14 3oz s89 No204-1/4 Scale 174 ozs 99501 V[7V kJO 203 13 Scale 236ozsI6 100 55PORT5MAN o BARNSTORMER- FULL RODS Oo RUSTfl/C C *s4J5 PILOT KIT LitSike 0OV lOthS 055t, pad,0 Ktt csntates PAst head hornet spod cap gossips OJacket. Easy asoornitie aho tjhsh Height WeightLOW Peicee5 ,No1O9t OScaip310Otoa5 59/5 4 No tOO t SRCOieO8tI 400sd%hc NO 04- aScaleadottao7Sh*sOme01 No tOg t iScale5-34240sl4~ simple tOsewtng5 Astounding htOliOeqt4irea0 4 attainable plastics.. ODoe tothete5temeti9et Weight Oat trntpiotcatoii ooa5o idiOt 0boOtS WiicaoeitttieothoettoctohthetaihctOtVootaiCatt 0 Send slOO Catalog SI Ne YOtt state RoOdoots add 75 sales tOO. Send Check ot- MO. cO Os Ai Oss 3 seeks cseck toctear 5 s DGA Designs 5 5 DGA 55 OGA Designs Reassembling gear train takes little sleight hand Put servo top section top cover separate Dunham D-l As top cover will remain place unassisted until case bottom can fastened wrap some tape around assembly retain cover no light can get Shorten remaining free lead CL-2 LATCH FOR COAL ItATCtI CAGtOPY & tdIttO AINPIN 2-STAGE PRESSURE STAG MORE GOODIES CANOPY TRACK AIRPIN PRESS GUAGE CUSTOM Ant CYLINDERS PROPHUT/SPINHER ATTACH EXT PROPEUTS FUR P-It PItU ete &IE OPERATES LATCH tTLAS Oev F2tGfltES STItoNGI ltD TIMER KITS SEND SASE FOR INFO DEALER INQUIRIES INVITED PHORE3O 73161 ROBINAIR E P 0 80X8770 CORAL SPRINGS FLORIDA33O75 MINICYLINDERS LED anode make soldering loop will later attach blue wire coming board #1 install motor point Rotate gears output gear neutral put output arm onto shaft neutral also Leave out arm retaining screw servo completed power should see bright red glow LED look down through top shaft Circuit board assembly As mentioned before circuit board #1 actually Heathkit part #238-95 using pre assembled board Heath servo leave following parts board power transistors motor leads servo con necting cable plug 1 0sF tantalum capacitor some units 22F 47F tantalum capacitor 001/LF ceramic capacitor IC Remove other parts Clip parts off above board try salvage Cut off flush top surface board will now very easy unsolder remaining stumps shake off board ruining foils process starting new board mount IC first being sure correctly oriented foil pad very narrow extends around three edges board 48-volt foil notched indented end IC will go middle section foil #1 pin will connect foil directly have provided diagram foil pattern copyrighted have identified holes use lettering top view board Fig 6 Assuming using red white black green color-coded servo connecting cable Heath has always used connect red wire hole marked B nearest pin #1 IC cases told connect wire component solder joint though another connection made later point system uses different color code youre own Connect black wire cable hole W also marked B- Connect green wire hole N nearest IC pin #12 cable has white wire clip plug strip out cable Use later needed Install two MPS6562 transistors leads marked transistor body EBC must go hole labeled corresponding letter see diagram sure leads short enough transistor does stand above board Install 47MF tantalum capacitor plus lead going hole T minus lead through hole U can use metal-cased type Heath used used dipped tantalum because fits better precision capacitor re quired Install OO1tF 1000 pF capacitor holes R S Heath used tubular unit used tiny disc capacitor Digi-Key just fits Again precision point required Install lOOK resistor RiO body standing up vertically hole X top lead bent over sharply enter hole Y 1 0MF 22FF dipped tantalum capacitor also destined holes X Y will installed later Install 82K resistor holes K L may necessary change value resistor depending servo operates place 22tF capacitor originally used holes F H install 1N914 diode F unbanded end down board left standing vertically later insertion #2 board Lay #1 board aside Prepare #2 board check shorts Borrow ohmmeter have set R x 1000 Touch meter lead foil pads touch other lead successively foil pad bordering first meter does deflect move another foil pad test its neighboring pads same man ner two foils produce indication short use X-Acto knife cut dividing lines deeper remove short sure absolutely no shorts between two foil pads proceed installation electronic components Install two 10K trimpots proper places non-foil side board should stand about %2-in high no Install R6 220K lies along left side board Position body resistor installed will act insulator against bare lead R3 Install two short bits bare wire holes opposite sides clearance notch end board Continued page 140 138 Model Aviation 45 m GEAR MECHANICS FOR BIGGIES Now Can Drill Grind Cut Sand Polish IN PLACES YOU NE VER COULD BEFORE FiRST TIME AVAILABLE great new precision tool has tough ABS housing hardened metal gears Iltetime lubricated bearings Attaches seconds Dremei Moto-Tool models #270 #280 #370 #380 Sears Craftsman rotary tools MUST FOR THE SMALL TOOL WORK SHOP R NOW AND SAVE Use thin onu~ send name addresn payment MICROUARKS Box 5112-3l3eCllnton NJ 08808 E Send n, 'a YES Send ______ RIGHT ANGLE DRIVES Item #50353 24-HOUR CREDIT CARD PI4ONEt 1400-225-1066 $1700 plus $200 shipphig andemtand dl am mm- lEt NJ 201-4644764 pletely satisfied may retum order en immediate refund NAME_______________________________ [ICheclr enclesed NJ residettla add 6% nolan tan [Charge [I VISA [I MaulerCard []AMEX ADDRESS___________________________________ Aoct#_____________________ [I Ship order C 00 $200 additionalCIlYSTATE______ ZIP ______ will connect #2 ground foil #1 ground B other will connect #2 22-volt B foil 22-volt pin IC Install R3 2200 ohms stand ver tically bend bare lead necessary go under R6 Install R4 2200 ohms flat board laid down Install R7 lOOK position shown Install C6 22tF dipped tantalum short negative lead board Leave positive lead long can connected board #1 later Cut 1-in length stranded orange wire Bare end twist strands together before soldering make insertion circuit board holes easier Connect end circuit foil board #2 shown Cut 2-in lengths blue black green orange wire prepare described previously 1-in stranded wire Connect blue wire top ofRi board #1 green black orange wires board #2 shown top Fig 5 Mount board #2 proper end board #1 components of#2 will overhang of# 1 short bits ofbare wire previously soldered lower end #2 should now bent downward fit vacant holes board #1 boards should form right angle notch board #2 should fit over end IC flush end Feed entire length positive lead 1 N9 14 diode through hole X board #2 Cover lead Teflon tubing bend over connect foil pad same place bare lead R7 connected Solder clip off excess lead Install lMF polyester capacitor Cl holes X andY lead goes through same hole used 1N914 diode Solder diode lead clip off excess wire leads must belong enough capacitor straddles top R3 Bend lead going through hole Y solder wiper terminal pot R8 Connect free end 1-in orange wire hole H shown Fig 6 other wires black green blue orange go LED-LDR photoelectric assembly gear case compartment Terminals assembly brought through gear case bottom feedback pot body removed Cut two pieces wire brown other white length 1 in, prepare ends before Put brown wire through hole M white wire through hole AZ Connect other ends wires motor follows white red positive terminal brown other terminal Connect CS 05F cer amic disc across motor terminals leads CS should left long enough extend down sides motor out way lead going red terminal must insulated other lead can left bare must grounded case Except connections photo electric assembly circuit board work now finished black wire connected junction LED LDR leads green wire junction LDRs orange wire remaining LDR lead blue wire anode re maining free end LED See ex planation Fig 5 motor removed pops right out gear train engaged plug servo receiver servooperator Turn power look down through top output shaft should see bright glow LED Though have built unit correctly will still almost certainly completely out adjustment Leave motor out gear box ie installed servo top section top cover place over gears photoelectric assembly Take off case bottom turn power motor should run transmitter off might initial twitch will run continuously until transmitter turned motor does begin run smoke LED does glow have defect construction Unplug servo look solder bridges misplaced parts other things electronics kits caution about unit OK far PRODUCTS FOR TIW n tmau Mf Unflet lete Line Exhaust Systems Tuned Pipes led Tuned Pipes Headers uri Mufflers Expansion Mufflers Helicopter Ball Mufflers ialized Exhaust Systems Unsurpassad Wnk,smnohin F Prftrmanc 140 Model Aviation New Robart RIGHT ANGLE DRIVE Dremel Moto-Tools U motor running turn transmitter motor will likely run direction unless struck lucky will stop reverse move control stick Shut receiver off adjust travel pot R2 extreme right its range looking top point maximum travel will reduce later procedure Make sure both transmitter receiver set servo arm neutral center adjust centering pot R8 point motor either stops oscillates Shut off receiver engage motor gear train Turn receiver back output arm runs side wont come back reverse leads motor start over correct motor connection may result servo arm oscillating though no command has given phenome non should cease travel pot readjusted now set travel pot mid-range arm comes rest point off-center set linearity pot R5 center positioning servo arm Now check 450 travel side center travel control affects total amount travel linearity control affects amount travel side center three controls centering linearity travel interact affects others may necessary go over several times Dont strive perfection making adjustments though because wont get finished servo oscillates IC may sensitive ones requires change 82Kresistor R9 value 68K 56K does oscillate fact seems underpowered change R9 either lOOK 120K changes will require small amount recentering given sudden large amounts stick action under no-load conditions servo will overshoot immediately re turn commanded position due lag response time LDRs confronted sudden large change brightness Since servos modeling environment rarely operate out some kind load would appear no problem Although further development servo might result eliminating two pots would seem 2K centering pot will always need retained can visualize though unit lower part output shaft shadow mask could independently adjustable respect output gear itself would friction adjustment could set top servo just servos now would require some delicate machining Im working Im also process trying adapt photoelectric concept use Signetics NE544 IC have little luck servo operates perfectly itself used other servos kind causes buzz jump oscillate Signetics chip does require additional external transistors does Kraft IC appeal smaller lighter still has experimenting have questions comments please write author George Gibson RR 1 Box 157 Fountain MI 49410 RC Soaring/Blakeslee Continued page 41 AMA did recognize Soaring time contest became bigger single AMA event premier event year event run Dan drew over 200 com petitors over country com petition its finest meet names like Mark Smith Dave Shadel Otto Heithecker Don Edberg Warren Plohr LeMon Payne Col Bob Thacker John Baxter Dave Thornburg Bob Gill Dale Nutter Jeff Mrlik Dwight Holly people flew against another single major contest today Glider pilots travel AMA Nats like did SOAR Nationals Dan Pruss ran class contest participation SOAR Nats reasons Soaring finally added AMA event Thank Dan Pruss will always treasure people experiences because Kurt Rosner fellow Rocky Mountain Soaring Association member favorite bird shot down off-field interference prompted Kurt try find Out what hit him So went out bought frequency scanner found commercial station operating 10 kHz below channel 44 First lets have Kurt describe scanner Regency MX500 may first readily-available new breed communica tions receivercontinuous coverage 25 550 MHz Other receivers give several seg ments bands within range dont give access example RC channels 72 MHz does frequency-synthesized no crystals keyboard-controlled alphanumeric LCD display comes nifty compact package can program 20-channel scanner set up search between two frequencies steps 5 125 25 kHz AM NFM WFM narrow- wide-band FM can selected example might want program up 20 RC channels Scan mode Search 720 730 MHz 5 kHz steps find potentially troublemaking signals lurking between RC channels area MX500 comes plug-in telescoping antenna 120-volt adapter cable install cigarette-lighter plug whatever cars 12-volt battery mounting bracket got CW Electronic Sales Denver $299 recently reduced $415 first hit market $600 Two nega tives instruction book skimpy doesnt cover keyboard-control capabilities unit Second little gem may distract real hobby Its imported Regency Electronics Inc 7707 Records St Indianapolis IN 46226 Kurts second step contact District IX Frequency Coordinator Steve Mangles lives Denver Steve found offender mobile phone service broadcasting data voice signals directionally Denver towards Boulder Kurt got hit Small consolation Kurt can hear signal loud clear new scanner Steve also learned same company L7ZY U L2 2U OOO LYUJLiI9 SEE OUR BACK COVER AD THIS ISSUE tested Maloney 100 first off quarter scale Cap 20L thai weighed about 15 pounds model first flown 23 cdee rich Zenoah G-23 Frar*ly Maloney 100 would get model trp air could loop level flight model under powered moat people standards Robinhood 80s 12 1/2 ounds fly wel i ntly bulit 90 sized Long John again shortened nose came 10 1/2 pounds model complete flaps fiAt symmetrIcal airfoil model seemingly will maneuver asked flaps down lands about Smiles per hour hope builders smaller Long John will get produce thla sIze kit Weve Modeltech develop two airplanes around Maloney 100 engine Jose StIk Dragon Lady Both modele fly great kept light designed Export 7 ch aystem w14 servos Maloney 100 Robinhood SO Modeltech Dragonlady Modeltech Joss Silk except outsIde loop J 10 1/2 pounds Robinhood will outslde loop very well cut nose back Robinhood 80 put firewal about 1 inch windshleld meets fuselage Notce cowied engine photo model uses small servos still fling 1200mAh battery peck fother reason thanspendalotof out Presently retaling Expert 7 channel system four servos NiCads transmitter flight packs charger neck strap frequency flag $33995 moment might lid retailers -both hobby mail order shops sefling thle system low $15000 terrific buy compared what get some ether systems br kind money fear prIce system will probably going si little bit near future because continuing devaluation US Blail $33995 $19995 $8995 $22495 $15995 j2ZJ u IQ GOQ G2ThLD 8960 Rossash Ave Cincinnati Ohio 45236 Phone 513 793-5900 x 214 557 January 1987 141 JeJtatmtlId maximize performance Maloney 100
Edition: Model Aviation - 1987/01
Page Numbers: 36, 37, 38, 39, 137, 138, 140, 141
Photon Servos two parts move against other destined wear out servos use translates feedback pot begins deterio rate time first moves have searched way avoid mechanical weak link now engineer own ranks may have come up photoelectric feedback system built around Dunham mechanics feedback pot housing has removed arrow points out light-dependent resistors ALMOST EVERY RC FLIER knows what feedback pot Some may have learned about hard way culprit behind crash best piloting skills couldnt have prevented causes trouble other part servo supposed necessary evils wed like able Its little carbon-coated vari able resistor servo has taken apart cleaned lubricated often maintenance isnt done servo arm will eventually become erratic jiggling jumping trying run continuously happens can generally kiss model good-bye feedback potentiometer used continuously-variable voltage divider fixed regulated voltage applied across pot wiper rotated servo motor through reduction gearing voltage divided continuously wiper moves its amplitude completely dependent upon position wiper therefore position output arm voltage governs duration reference pulse generated 36 Model Aviation 1 p-- answer EGeorge Gibson CuttheLDR retaining clipfromatin can lid use CyA glue LDRs place servo compared incoming control pulse receiver duration two pulses identical cancel out servo stops Any irregularity carbon surface pot element depending its character will cause malfunctions addition wiper slides over ele ment gradually wears away primarily over center travel tiny bits wiper metal depositedcausing element behave erratically evil weve put up ever since inception digital RC time Kraft Systems tried eliminate problems feedback pot putting variable capacitor refer ence pulse generator un provement system problems its own should know worked about 10000 Heathkit version servo As trend smaller smaller servos variable capacitors can made small approach phased out meantime quality pots increased price evident pots would always periodic maintenance nuisance Carbon button wiper contacts another im provement button popped out wiper arm saw happen re sulting problems could catastrophic late 1 960s John Cline F&M Electronics experimenting differ ent ways produce servo having incorporate feedback pot outcome research what called variable inductance servo see American Aircraft Modeler February 1968 relatively large metal-cased servo 1 1/16 x January 1987 37 Li Left scale drawing shows clip formed secure LDRs Note rim LDR recessed plastic case Right Remove feedback pot body Dremel tool knife Drill hole #2 screw cut notches wires look closely atthe arrow right can seethe LED peeking through shadow mask has cut hollow output shaft arrow left shows snugly clip holds LDRs Adjust shape clip until sure LDRs cannot move 1 x 3 available linear output eight-pin plug Chine stated research tried photoelectric feedback system before development light-emitting diodes LEDs photoelectrics necessarily de pended filament-type light bulb Cline recognized would im practical four counts mechanism would subject total failure warning whenever filament burned out would have little ability withstand typical model vibrations would cause ex cessive battery drain economically impractical Despite its drawbacks felt would work dont know variable inductance servo ever marketed never saw use photoelectric concept John Cline advanced just waiting technology make practical LEDs light-emitting diodes LDRs light-dependent resistors appeared commercial market couple years after went work Heathkit Co assignments evaluate pre-pro duction run Thumb Tac first photoelectric tachometer appear RC market used transistor-sized pho tocell aforementioned LDRs Thumb Tac developed engineer friend Heath successful both technically com mercially earned him advance grade both members Southwest Michigan Whirlwinds RC Club often discussed possibility using LDR Thumb Tac kit variable resistor reference pulse generator would eliminate trouble some wiping mechanical contacts conventional feedback pot prob lem foresaw LDRs have objectionable warm-up characteristic friend designed special IC chip com pensate LDR drift various reasons eventually dropped project Still idea stuck head decided try another approach keep simple Instead using single LDR requiring special IC retained regnlar Kraft IC used two LDRs series replace feedback pot LDRS carefully matched both would vary resistance same amount same direction During warm-up assuming equal illumination voltage junc tion would remain same junction point course would correspond wiper connection eliminated feed back pot make voltage vary such way simulate movement wiper feedback pot illuminating source would moved away neutral position throw light LDR other voltage junction would rise fall according resistor getting light viable choice light source LED Theyre small immune vibration have very economical current drain theres no filament burn out Almost John Clines problems solved simple device built couple servos using Kraft/ Heath mechanics made LED movable back forth between two LDRs proved concept would work making light source movable required either sliding contacts flexible leads knew inevitably would break cause catastrophic failure both light source light detector stationary moveable mask would have rigged between such way mask moved way other would partially cover uncover LDRs get same effect moving light source would eliminate sliding contacts flexing leads sitting just staring some servo parts constructive idea head suddenly great brainstorm blew through between ears chose servo output gear output shaft might have room gearbox underneath output gear shadow mask knew Dunhams R&R made servo #2 gear located over motor instead under output gear Kraft Heath did ordered four hadnt specified color received white proved problem allowed extraneous light leak onto LDRs tried painting cases black paint worked time flaked off easily Thereafter ordered black cases first successful shadow mask made anodized aluminum glued output shaft required two LEDs although would have increased current drain LEDs series could have simpler Another minor brainstorm resulted putting single LED inside output shaft carving hole side shaft illuminate LDRS As shaft rotated first LDR other would favored light would have effect similar moving light source insert LED bottom end hollow shaft remove short splined shaft attaches pot wiper As brass slug would dis carded along wiper needed devise another way center servo wanted make linearity travel centering adjustable least first few experimental versions O needed second circuit board carry three trimmer pots 50-cent type well some additional resistors capacitors Since no longer needed feedback pot way decided carve off down bottom case make room extra board its parts gave lots room electronics compartment built some ser vos two decks board above other parallel found difficult circuit testing replace parts regrouped ended up two boards mounted right angles mechanics electronics combined oriented shown fit inside servo case gear case cover put first travel adjustments done everything installed case layout has worked out OK far feel production two pots perhaps threecould eliminated single-board electronics would result Replacing troublesome failure-prone feedback pot wasnt simple hoped has definitely worth test-flew three-pot version described over period three years save linkage adjustment set main tenance-free Performance superior hadnt receiver failure causing fatal case fly-away-itis Id flying yet plan patent photon servo Im publicizing notion someone will develop further Adjustments both Kraft Heath servos feedback pot located collector reference pulse generator Its IC its still made up transis tors first substituted LDRs same position travel linearity good tried LDR double base circuit linearity still good Finally put diode base circuit reverse-biased would isolated except base driven neg ative cutoff pulse linearity 38 Model Aviation rough prototype set circuit boards shows perpendicular board layout electronics section vertical board Cir cuit Board #1 available Heathkit other constructed per text better could adjusted 10K pot connected across two LDRs wiper arm attached LDR junc tion Early project found LDR used Thumb Tac suitable servo use since high-resistance type contacted Clairol manufacturer found producing LDRS resistance ranges supplied performance data ordered 10 lowest-resistance range set up test jig Surprise resistance under identical test conditions varied much 300% batch 10 two nearly identical enough servo rest could matched up ordered another 100 got enough matches 29 servos dont have same value just have matched pairs Naturally choices available matches As no longer mechanical feedback pot need alternative method adjust servos centering replaced 1K load resistor collector circuit reference pulse generator inexpensive 2K pot small variation light intensity LDRs will result relatively large change voltage junctionmuch equivalent rotation feed back pot Resistors R2 R3 R4 form network attenuate voltage output arm can rotate farther before control voltage reaches value will result stop Resistor R2 also trimmer pot used adjust length servo travel some later versions mounted LDRs simply gluing place cyanoacrylate CyA units immediately began experience high fail ure rates though two earlier versions LDRs held untidily place wire clips still worked fine Out curiosity added CyA servos next day failed also assume CyA caused failures although dont know Mounting now done sheetmetal clips made top dog food can see pattern have no failures photon servo will draw current standard servo willbut sig nificantly neutral two LDRs will draw maximum about 3 mA LED about 5 mA comparison feedback pot draws 13 mA consider servos typically draw about 20 mA idle least 150 mA under load extra 4 mA insignificant over three years testing have never experienced battery-drain problems schematic parts marked * already installed original circuit board Heath part #238-95 will have make #2 circuit board simple have used three methods con struction Cut-and-peel copper foil very thin PC board material conventional etching non-foil perforated board using bent-over component leads interconnections As two PC boards will assembled 900 other board #2 must notched fit end several sizes 4-watt re sistors market sure get smallest size go -watt com ponents circuit draw enough current get warm trimmer pots used Digi-Key Corp enclosed sealed against dust As 6mm pots take up room #2 board resistors capacitor must carefully located interfere access diagrams should help avoid trouble Also since pots adjustable both top bottom can drill -in holes board pots can set non-component side should first attempt building servo youve successfully assembled kit servos should have little difficulty After boards Heath Some components will left off Heath board incorporated second others will change value type have Heath board already built up can use making necessary modifications Construction After trying servomechan isms several manufacturers decided Dunham D-1 particularly suited purpose has gear arrangement required plus hollow output shaft can modified use shadow-mask gears are of nylon filled Continued page 137 January1987 39 LORs non-polarized either end can connected B LEDs polarized will glow leads reversed Although shown fiat two boards will mounted right angles Note interconnections between two boards LED LDRs q1~ WEIGHT-MATES HEAVY DUTY FABRIC WEIGHT BAGS FOR BUILDING TRANSPORTING & FIELD TIE-DOWN Easily filled w/sand shot up 5 Ibs Five 4x6 bags per package Conforms curvatures Complete instructions $695 postage & handling AZ residents add 35X tas Radio Technique/Myers Continued page 133 transmitter receiver few AM FM sets already conform guidelines So can expect early part 1988 will see low band occupied some pretty good stuff will up keep way vigorously persuading rebels mend ways having equipment serviced periodically keep operating should Based transmitter tests performed three Nats three trade shows seems some AM FM transmitter designs can quali fied slight modifications same informa tion makes seem highly unlikely transmit ters now old channels BN/W through GN/W will ever qualified just basis costs involved Receivers another matter Very few exist ing receivers qualify except Kraft -8FD -8FDS dual-conversion PCM receivers like Simprop PCM-20 Multiplex time gets print expect other qualified receivers will put circula tion Ace R/C Airtronics Circus Futaba others will have own shopping leave reviewing business friend Bob Aberle does very well read Flying Models magazine dont already George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Photon Servos/Gibson Continued page 39 material glass fiber makes very sturdy Dunham guarantees free replace ment part fails reason including crash damage small lots sell approximately $7 lots 100 little over $2 Re member specify black cases order Disassemble servo com pletely careful lose parts particularly small gear pins output gear attached wiper rotor splined brass shaft extends 1GRATE-SHAPES SANDING BLOCKS GS 101 3/u XG5103 K G 5 105 &3k 90Vsw/% X GS 102 /o & m GS 0 %&wR Grit sides Always consistantly rounded edges Long-lasting silicon carbide grit Combo Package 101 102 & 103or specify three $1195 P & H AZ residents add 60 ta Single GRATE-SHAPES $495 P & H AZ residents add 255 tas products guaranteedDealers invited SEND cHECK OR---MONEY ORDER TO Bell Rock Industries Hwy 179-Suite 108 Sedona AZ 86336 284-1808 through bottom gear case Care fully pull upward gear will require some force will separate brass shaft will using shaft wiper project use method want separating damage bearing hole Unless old string saver discard shaft wiper feedback pot body molded integral part servo center section gear case bottom may split several segments can sawed off individually See Fig 4 use Moto Tool cutoff wheel carve stumps flush sharp knife Make two t/ie-in slots Moto cutoff tool drill hole clear #2 screw Now select red LED will fit bottom end output gear shaft LED should wide-angled should fit snugly turn freely flange LED must also sanded off allow inserted deep enough inside shaft Assemble output gear servo top section place LED leads extending down through bearing hole Pull LED down firmly grasping leads put droportwoof5-min epoxy bearing hole around leads use CyA anywhere else servo Let epoxy set firmly before proceeding further remove top section output gear retaining clip two LDRs made top tin can Spring brass bronze could also used dont recommend aluminum case must thin strong Dimensions details given Figs 2 & 3 LDRs will lay flat sides have rim prevents attempt grind flat spot rim though will destroy hermetic seal Instead use defunct metal-cased transis tor same size LED mount place retaining clip heat rim soldering iron until plastic melts E -% BOOSTER Space Age Charging Has Arnvedl Convenient solar charging will solve battery charging problems flying sight boosting batteries between flights Safe 100 MA Charge Rate Autumatic Cat-OS Full Charge High Efficiency Under Cloudy Cosditioou Charges-Both RX asd TX Simultaneously Popular Radio Systems Using 48 96 Volts Handy Plug-In Charging Cord Adjustable Angle Bracket Bailt Everyday Use RaggedLightweighl Easy Curry Handle Full Warranty $7995 Introductory Dtter $450 Shipping & Handling USA AZ Residents Add $400 Tax allows rim sink surface too much heat youll ruin plastic case recess melted case LDRs can now made set flat held place retaining clip Mount shown Fig 5 bending bottom lead LDR downward through Yt6-in slots other lead LDR will bent forward two joined can soldered retaining clip desired junction green wire board #2 will later soldered removing flange LED during its installation also removed flat flange identifies cathode lead install diode properly must re-identify lead connect two wires positive negative outputs flight battery solder 1000-ohm resistor end positive lead Touch negative wire LED lead free end 1K resistor other lead LED does light reverse connections LED lights lead going 1K resistor anode other lead cathode Bend cathode lead over flat solder lead LDR2 comes through slot Later black wire board #2 will connected also Now shadow mask Look bottom side output gear neutral point raised ridge about e-in wide radiating shaft out ward rim Take sharp point scribe line shaft center ridge downward bottom end shaft parallel its axis point line om end make tiny punch mark drill hole through shaft wall Enlarge hole /u6-in drill %2-in drill Dont drill through both sides shaft though Square up hole sharp X-Acto blade shadow mask complete January 1987 137 DGADelignsss OGA Designs DGA Designs. DGA Designs es DGA Designs o5 S *DARNED GOOD AIRMEN Lightest weight Pilots Available Ia0 * FULL BODY PILOT KIT e ke Vny e abbe pa-ts Easy assenble finish Kit contains Pilot head hands boots heintet5 Ocap goggles full tentplates easy inett-ttctiOns Fully positionable too0 Height- Weight-NEW LOW Pttces-5 NO206 .1/6 Scale lls 2 oz s72 rJ\rK NO206 5 Scale 14 3oz s89 No204-1/4 Scale 174 ozs 99501 V[7V kJO 203 13 Scale 236ozsI6 100 55PORT5MAN o BARNSTORMER- FULL RODS Oo RUSTfl/C C *s4J5 PILOT KIT LitSike 0OV lOthS 055t, pad,0 Ktt csntates PAst head hornet spod cap gossips OJacket. Easy asoornitie aho tjhsh Height WeightLOW Peicee5 ,No1O9t OScaip310Otoa5 59/5 4 No tOO t SRCOieO8tI 400sd%hc NO 04- aScaleadottao7Sh*sOme01 No tOg t iScale5-34240sl4~ simple tOsewtng5 Astounding htOliOeqt4irea0 4 attainable plastics.. ODoe tothete5temeti9et Weight Oat trntpiotcatoii ooa5o idiOt 0boOtS WiicaoeitttieothoettoctohthetaihctOtVootaiCatt 0 Send slOO Catalog SI Ne YOtt state RoOdoots add 75 sales tOO. Send Check ot- MO. cO Os Ai Oss 3 seeks cseck toctear 5 s DGA Designs 5 5 DGA 55 OGA Designs Reassembling gear train takes little sleight hand Put servo top section top cover separate Dunham D-l As top cover will remain place unassisted until case bottom can fastened wrap some tape around assembly retain cover no light can get Shorten remaining free lead CL-2 LATCH FOR COAL ItATCtI CAGtOPY & tdIttO AINPIN 2-STAGE PRESSURE STAG MORE GOODIES CANOPY TRACK AIRPIN PRESS GUAGE CUSTOM Ant CYLINDERS PROPHUT/SPINHER ATTACH EXT PROPEUTS FUR P-It PItU ete &IE OPERATES LATCH tTLAS Oev F2tGfltES STItoNGI ltD TIMER KITS SEND SASE FOR INFO DEALER INQUIRIES INVITED PHORE3O 73161 ROBINAIR E P 0 80X8770 CORAL SPRINGS FLORIDA33O75 MINICYLINDERS LED anode make soldering loop will later attach blue wire coming board #1 install motor point Rotate gears output gear neutral put output arm onto shaft neutral also Leave out arm retaining screw servo completed power should see bright red glow LED look down through top shaft Circuit board assembly As mentioned before circuit board #1 actually Heathkit part #238-95 using pre assembled board Heath servo leave following parts board power transistors motor leads servo con necting cable plug 1 0sF tantalum capacitor some units 22F 47F tantalum capacitor 001/LF ceramic capacitor IC Remove other parts Clip parts off above board try salvage Cut off flush top surface board will now very easy unsolder remaining stumps shake off board ruining foils process starting new board mount IC first being sure correctly oriented foil pad very narrow extends around three edges board 48-volt foil notched indented end IC will go middle section foil #1 pin will connect foil directly have provided diagram foil pattern copyrighted have identified holes use lettering top view board Fig 6 Assuming using red white black green color-coded servo connecting cable Heath has always used connect red wire hole marked B nearest pin #1 IC cases told connect wire component solder joint though another connection made later point system uses different color code youre own Connect black wire cable hole W also marked B- Connect green wire hole N nearest IC pin #12 cable has white wire clip plug strip out cable Use later needed Install two MPS6562 transistors leads marked transistor body EBC must go hole labeled corresponding letter see diagram sure leads short enough transistor does stand above board Install 47MF tantalum capacitor plus lead going hole T minus lead through hole U can use metal-cased type Heath used used dipped tantalum because fits better precision capacitor re quired Install OO1tF 1000 pF capacitor holes R S Heath used tubular unit used tiny disc capacitor Digi-Key just fits Again precision point required Install lOOK resistor RiO body standing up vertically hole X top lead bent over sharply enter hole Y 1 0MF 22FF dipped tantalum capacitor also destined holes X Y will installed later Install 82K resistor holes K L may necessary change value resistor depending servo operates place 22tF capacitor originally used holes F H install 1N914 diode F unbanded end down board left standing vertically later insertion #2 board Lay #1 board aside Prepare #2 board check shorts Borrow ohmmeter have set R x 1000 Touch meter lead foil pads touch other lead successively foil pad bordering first meter does deflect move another foil pad test its neighboring pads same man ner two foils produce indication short use X-Acto knife cut dividing lines deeper remove short sure absolutely no shorts between two foil pads proceed installation electronic components Install two 10K trimpots proper places non-foil side board should stand about %2-in high no Install R6 220K lies along left side board Position body resistor installed will act insulator against bare lead R3 Install two short bits bare wire holes opposite sides clearance notch end board Continued page 140 138 Model Aviation 45 m GEAR MECHANICS FOR BIGGIES Now Can Drill Grind Cut Sand Polish IN PLACES YOU NE VER COULD BEFORE FiRST TIME AVAILABLE great new precision tool has tough ABS housing hardened metal gears Iltetime lubricated bearings Attaches seconds Dremei Moto-Tool models #270 #280 #370 #380 Sears Craftsman rotary tools MUST FOR THE SMALL TOOL WORK SHOP R NOW AND SAVE Use thin onu~ send name addresn payment MICROUARKS Box 5112-3l3eCllnton NJ 08808 E Send n, 'a YES Send ______ RIGHT ANGLE DRIVES Item #50353 24-HOUR CREDIT CARD PI4ONEt 1400-225-1066 $1700 plus $200 shipphig andemtand dl am mm- lEt NJ 201-4644764 pletely satisfied may retum order en immediate refund NAME_______________________________ [ICheclr enclesed NJ residettla add 6% nolan tan [Charge [I VISA [I MaulerCard []AMEX ADDRESS___________________________________ Aoct#_____________________ [I Ship order C 00 $200 additionalCIlYSTATE______ ZIP ______ will connect #2 ground foil #1 ground B other will connect #2 22-volt B foil 22-volt pin IC Install R3 2200 ohms stand ver tically bend bare lead necessary go under R6 Install R4 2200 ohms flat board laid down Install R7 lOOK position shown Install C6 22tF dipped tantalum short negative lead board Leave positive lead long can connected board #1 later Cut 1-in length stranded orange wire Bare end twist strands together before soldering make insertion circuit board holes easier Connect end circuit foil board #2 shown Cut 2-in lengths blue black green orange wire prepare described previously 1-in stranded wire Connect blue wire top ofRi board #1 green black orange wires board #2 shown top Fig 5 Mount board #2 proper end board #1 components of#2 will overhang of# 1 short bits ofbare wire previously soldered lower end #2 should now bent downward fit vacant holes board #1 boards should form right angle notch board #2 should fit over end IC flush end Feed entire length positive lead 1 N9 14 diode through hole X board #2 Cover lead Teflon tubing bend over connect foil pad same place bare lead R7 connected Solder clip off excess lead Install lMF polyester capacitor Cl holes X andY lead goes through same hole used 1N914 diode Solder diode lead clip off excess wire leads must belong enough capacitor straddles top R3 Bend lead going through hole Y solder wiper terminal pot R8 Connect free end 1-in orange wire hole H shown Fig 6 other wires black green blue orange go LED-LDR photoelectric assembly gear case compartment Terminals assembly brought through gear case bottom feedback pot body removed Cut two pieces wire brown other white length 1 in, prepare ends before Put brown wire through hole M white wire through hole AZ Connect other ends wires motor follows white red positive terminal brown other terminal Connect CS 05F cer amic disc across motor terminals leads CS should left long enough extend down sides motor out way lead going red terminal must insulated other lead can left bare must grounded case Except connections photo electric assembly circuit board work now finished black wire connected junction LED LDR leads green wire junction LDRs orange wire remaining LDR lead blue wire anode re maining free end LED See ex planation Fig 5 motor removed pops right out gear train engaged plug servo receiver servooperator Turn power look down through top output shaft should see bright glow LED Though have built unit correctly will still almost certainly completely out adjustment Leave motor out gear box ie installed servo top section top cover place over gears photoelectric assembly Take off case bottom turn power motor should run transmitter off might initial twitch will run continuously until transmitter turned motor does begin run smoke LED does glow have defect construction Unplug servo look solder bridges misplaced parts other things electronics kits caution about unit OK far PRODUCTS FOR TIW n tmau Mf Unflet lete Line Exhaust Systems Tuned Pipes led Tuned Pipes Headers uri Mufflers Expansion Mufflers Helicopter Ball Mufflers ialized Exhaust Systems Unsurpassad Wnk,smnohin F Prftrmanc 140 Model Aviation New Robart RIGHT ANGLE DRIVE Dremel Moto-Tools U motor running turn transmitter motor will likely run direction unless struck lucky will stop reverse move control stick Shut receiver off adjust travel pot R2 extreme right its range looking top point maximum travel will reduce later procedure Make sure both transmitter receiver set servo arm neutral center adjust centering pot R8 point motor either stops oscillates Shut off receiver engage motor gear train Turn receiver back output arm runs side wont come back reverse leads motor start over correct motor connection may result servo arm oscillating though no command has given phenome non should cease travel pot readjusted now set travel pot mid-range arm comes rest point off-center set linearity pot R5 center positioning servo arm Now check 450 travel side center travel control affects total amount travel linearity control affects amount travel side center three controls centering linearity travel interact affects others may necessary go over several times Dont strive perfection making adjustments though because wont get finished servo oscillates IC may sensitive ones requires change 82Kresistor R9 value 68K 56K does oscillate fact seems underpowered change R9 either lOOK 120K changes will require small amount recentering given sudden large amounts stick action under no-load conditions servo will overshoot immediately re turn commanded position due lag response time LDRs confronted sudden large change brightness Since servos modeling environment rarely operate out some kind load would appear no problem Although further development servo might result eliminating two pots would seem 2K centering pot will always need retained can visualize though unit lower part output shaft shadow mask could independently adjustable respect output gear itself would friction adjustment could set top servo just servos now would require some delicate machining Im working Im also process trying adapt photoelectric concept use Signetics NE544 IC have little luck servo operates perfectly itself used other servos kind causes buzz jump oscillate Signetics chip does require additional external transistors does Kraft IC appeal smaller lighter still has experimenting have questions comments please write author George Gibson RR 1 Box 157 Fountain MI 49410 RC Soaring/Blakeslee Continued page 41 AMA did recognize Soaring time contest became bigger single AMA event premier event year event run Dan drew over 200 com petitors over country com petition its finest meet names like Mark Smith Dave Shadel Otto Heithecker Don Edberg Warren Plohr LeMon Payne Col Bob Thacker John Baxter Dave Thornburg Bob Gill Dale Nutter Jeff Mrlik Dwight Holly people flew against another single major contest today Glider pilots travel AMA Nats like did SOAR Nationals Dan Pruss ran class contest participation SOAR Nats reasons Soaring finally added AMA event Thank Dan Pruss will always treasure people experiences because Kurt Rosner fellow Rocky Mountain Soaring Association member favorite bird shot down off-field interference prompted Kurt try find Out what hit him So went out bought frequency scanner found commercial station operating 10 kHz below channel 44 First lets have Kurt describe scanner Regency MX500 may first readily-available new breed communica tions receivercontinuous coverage 25 550 MHz Other receivers give several seg ments bands within range dont give access example RC channels 72 MHz does frequency-synthesized no crystals keyboard-controlled alphanumeric LCD display comes nifty compact package can program 20-channel scanner set up search between two frequencies steps 5 125 25 kHz AM NFM WFM narrow- wide-band FM can selected example might want program up 20 RC channels Scan mode Search 720 730 MHz 5 kHz steps find potentially troublemaking signals lurking between RC channels area MX500 comes plug-in telescoping antenna 120-volt adapter cable install cigarette-lighter plug whatever cars 12-volt battery mounting bracket got CW Electronic Sales Denver $299 recently reduced $415 first hit market $600 Two nega tives instruction book skimpy doesnt cover keyboard-control capabilities unit Second little gem may distract real hobby Its imported Regency Electronics Inc 7707 Records St Indianapolis IN 46226 Kurts second step contact District IX Frequency Coordinator Steve Mangles lives Denver Steve found offender mobile phone service broadcasting data voice signals directionally Denver towards Boulder Kurt got hit Small consolation Kurt can hear signal loud clear new scanner Steve also learned same company L7ZY U L2 2U OOO LYUJLiI9 SEE OUR BACK COVER AD THIS ISSUE tested Maloney 100 first off quarter scale Cap 20L thai weighed about 15 pounds model first flown 23 cdee rich Zenoah G-23 Frar*ly Maloney 100 would get model trp air could loop level flight model under powered moat people standards Robinhood 80s 12 1/2 ounds fly wel i ntly bulit 90 sized Long John again shortened nose came 10 1/2 pounds model complete flaps fiAt symmetrIcal airfoil model seemingly will maneuver asked flaps down lands about Smiles per hour hope builders smaller Long John will get produce thla sIze kit Weve Modeltech develop two airplanes around Maloney 100 engine Jose StIk Dragon Lady Both modele fly great kept light designed Export 7 ch aystem w14 servos Maloney 100 Robinhood SO Modeltech Dragonlady Modeltech Joss Silk except outsIde loop J 10 1/2 pounds Robinhood will outslde loop very well cut nose back Robinhood 80 put firewal about 1 inch windshleld meets fuselage Notce cowied engine photo model uses small servos still fling 1200mAh battery peck fother reason thanspendalotof out Presently retaling Expert 7 channel system four servos NiCads transmitter flight packs charger neck strap frequency flag $33995 moment might lid retailers -both hobby mail order shops sefling thle system low $15000 terrific buy compared what get some ether systems br kind money fear prIce system will probably going si little bit near future because continuing devaluation US Blail $33995 $19995 $8995 $22495 $15995 j2ZJ u IQ GOQ G2ThLD 8960 Rossash Ave Cincinnati Ohio 45236 Phone 513 793-5900 x 214 557 January 1987 141 JeJtatmtlId maximize performance Maloney 100