The simple modifications described article will give Astro Model 102 charger consistent output make impervious input voltage fluc tuations allowing charge battery packs driving field EBob Kopski SEVERAL MONTHS AGO regu lar monthly RC Electrics column promised information modification Astro Model 102 DC/DC Super September 1987 81 mop xcup TUTU IOfl9Uf unarge ouro ruiuuuiuu rung ewulun uno larger Oattery clips modified charger looks very much did originally Using white 6-ft lamp cord makes convenientto hook upthe model its visible grass Switching larger clips provides better connection car batterysomething current-hungry chargers should have other mode arent made range switch relabeled Sharpie marking pen read 1-14 lower position 10-22 upperpositlon Above inside original Astro DC/DC charger pencil points originsi component thats re wiredthe controi pot White wire timer meter will replaced resistor pair FiGURE 1 Char OUTPUT CURRENT AW 7 Set Point 4A P 12V Inpi 12 Left graph shows what happens th original modified chargeroutput currents input voitage isvaried Tests included two differentbatterypacksan 8-cell 1 2Ah pack being charged onthe 1-14 cell range a20 cciii 2 Ah pack beingchargedonthe 10-22 cell range smaller pack set up charge 4 amps 12-volt input larger pack set up 3 amps same input voltage input varied up down such might happen starting running car engine easyto see improvement mod makes Right Graph depicts variation charge current tars fixed inputvoitagetothe chargerovera 1 5-minute charge cycle Two different 12 Ah packs testedan 8-cell 20-cell initial charge current time 0 set 4 amps Start Radio Shack terminal strip shown left Cut down shown right bendtheterminalsgO Solder resistor R7 shown carefully driii out mounting lug hois 3/16 Modifications should begin instal lation two 1-ohm 10 watt resistors Ri R2 resistors actually wired parallel form /rohm current-sam pling resistor Both resistors will get hot during operation very important thatthev cooxied aluminum canaL Charger modification easy stall will significantly improve performance already very fine prod uct applications Heres what its about Astro Super Charger may thought fully adjustable voltage converter effect charger can take 12-volt input auto battery change lower higher values done setting range switch adjustable control knob Thus charging pack containing few cells charger set relatively low output voltage pack has cells higher normal 12-volt car battery voltage needed charger adjusted provide Its like having variable auto battery help clear up some confusion about product subject charger 82 Model Aviation Tne terminsi strip assemmy neia piece aytne meisi-tramee inductors mounting screw Position strip clear everything Label wires pot original location can retained Remove wire pot lug nearest front photo solder right-hand lug terminal strip Remove other two wires pot soiderthem left lug terminal strip mix up FIGURE 3 Astro DC-DC Super Charger Modification Schematic Remove knob control pot remove pot front panel Solder three short wiressuch leftover resistor leadsto pot lugs run wIres through proper holes circuit board Keep board snug againstthe pot additional strength route wires through two holes circuit board bringing wire U shape back up through adjacent hole clr cult board Securely solder wire both points goes through board automaticie does sense battery charge condition shut itself off Rather has standard 15-minute timer switch control charge duration perfectly acceptable way doing things fact charging timed charge Therefore modification does change aspect chargers operation However charger also regu lated what modification about regulated sense selected battery charge current inherently stable rather varies both charge condition terminal volt age battery being charged auto battery voltage driving As consequence often necessary keep eye charge current readjust control knob during charging cycle Personally Im used charging stable charge current after seeing well Astro 102 otherwise performed began wonder about modifying September 1987 83 two connectons REPLACE existing wire NOTE All components shown pcholeboard subassembly except Ri R2 panel Ri terminal strip /Ri lOw SOLDER TOSOLDER TO UPPER TERMINAL1L--V\/\J~J ILEFT TERMINAL OF TIMER-SWITCHI P2 lOwJOF AqIETER GREY ORANGER3 22kR4 10k Original Control Pot CW ROTATION Increases Output P51kN TERMINAL STRIP TRANSISTOR QiDETAIL Cl luf35v R6lk YELLOWII II15k WIRE DIODE DlCZ 2Zuf iSvK YELLOW WIRE TO LEFTGREEN WIRE TO ORIGINAL LUG OF ADDED TERMINALCHARGER CIRCUIT BOARD STRIP RiSee photo 8 WIRES FROM ORIGINAL CIRCUIT BOARD--ORIGINALLY CONNECTED TO CONTROL POT simple circuIt addition needed stabilize charge current limited number re quired parts makes easy task some soldering experIence very important work carefully correctly because mistake could damage charger FIGURE 4 Astro DC-DC Super Charger Modification uit Board Pictorial SPECIAL NOTE LEADS VARY--SO BE SURE YOUR TRANSISTOR CEB LEADS GD TO CORRECT LOCATIONS COLLECTOR GREEN WIRE TO OIARGER CKT BOARD YELLOW WIRE TO TERMINAL STRIP EMITTER BASE P3 THIS PICTORIAL IS TOP VIEW R4 control pot 9 QI JtLr7JDlCi//R5 JORANGE WIRE TO TIMERSWITCH ALL DOTTED VERTICAL LINES INDICATE FOIL CONNECTORS ON CIRCUIT BOARD SPECIAL NOTE PC-HOLE BOARD MUST BE CUT TO SIZE WITH SHOLE CONDUCTOR PATTERN LOCATED BETWEEN THESE ARROWS BOARD IS 17 HOLES WIRE TO PANEL METER Almost circuit modification components assembled small piece circuit board wire leads identif led color used original assembly may change colors change wiring locationsbe sure what doingi Attach green wire directly original charger circuit board underneath large metal-framed inductor wire colors mentioned throughout procedure reference four distInct colors could usedbut dont mix up locational Install other components nns circume ~ardasshownintheassembiydrawing careful get capacitor diode polarities correct Make sure transistor leads inthe approprIate iocationssomett5n515t0r choices have leads different locations Connect 6-in lead-out wires shown Standard RC wire Ace RC okay include output current stabilization article result pursuing idea simple additional circuitry described herein makes selected charge current much stable Once set have readjust charge value over 15-minute timer period best part about charging can done auto engine running can arrive field ready fly See Model Avi ation March July 1985 Just re member attempt charging batteries driving car modi fication could disastrous since input voltage variation occurs car runmng causes similar tremendous vari ation charger output current course everything else life somethings just gotta wrong thing sounds goodright Yup four disadvantages associated modification First circuit modification reduces two maximum number cells could otherwise charged cause added circuitry uses some available charger output voltage makes unavailable battery being charged Second modified charger uses slight ly current auto battery runs somewhat hotter result charger output current flowing through added sampling resistor R1-R2 have found no ill effects because Third trickle charge now unadjust able Ordinarily small trickle charge current can set charger timer off As rule never trickle charge anyway besides coarse scale meter doesnt permit readable values such low currents begin withso doesnt bother fourth disadvantage drawback under particular set circum stances Ill call fourth difference modification output current charger cannot turned completely zero lowest output about 12 amps control knob adjusts upward woukl disadvantage wanted charge very small cells such 250 mAh smaller Now feel youd like have described advantages can somehow make through life disadvantages read See works easy modiir Astro DC/DC Super Charger added circuItry charger modi fication consists assembling small circuit board usjng Radio Shack parts installing new subassembly DC/DC Super Charger changes original charger minimal re versibleso should ever want change back can original charger parts used onethe control pot wires rewired have follow sketches photos exactly work carefully Continued page 158 84 Model Aviation FIGURE 5 Astro DC-DC Super Charger Modification Misc Pictorial Details GREEN WIRE SI LITE t1Ii LAD IBITTED ORIGINAL POT WIRING SOLID RE-cONNECTIONS REItJVE add RI-R2 R2 WI RE REAR VIEW Left Pay particularattentlon rerouting wires original potentiometer mistake will cause extensive damage original charger circuit Right Parailel resistors Ri R2 replace wire orIgInally connecting panel meter timer switch Use short lengths 1 8-gauge lamp cord extend resistor leads required Ri R2 must epoxy-giued aiuminum panel heat-sink cooling purposes ORIGINAL CIRCUIT BOARD wider inductor V 0 inside completed sin u uiirur mmmi resistor ana wire going ins pilOt light should removed since InC trickle-charge circuit no longer functions original Reinstalithe control potwlth its newcircultboard attached intotheoriginal panel location Position circuit board clears everything Tighten pot mounting nut Reinstall control knob making sure pot turned fully CCW pointer t 7 n,lnk Trim fin. wire fr irnh -"er appropriate destinations PRACTICAL SIZED GIANT Order Canopies Available Plans sent Post-Paid within USA Send 5Oe Full Catalog Balsa Nick Ziroli 29 EdMar Dr Smithiown NY 11787 USA MODELS NICK ZIROLI Jets too Plans RK-20 RK-740 Ducted Fans Phantom38 span$1000 Viggen32 span$1000 F-1538 span$1000 Plan canopy$1500 516-234-5038 enclosing some photos modifications K&B 15 definitely improve ground rpm engine resulting airspeed As can see photograph stock crank left crank right has enlarged extra meat has taken out shaft area addition venturi has enlarged some 015 second photograph shows enlarge ment venturi well giving view back crank can see enlarged hole extra meat removed up near timing area particular cranks close around 620 after top dead center ATDC Ron Youngs Performance Engines will rework cranks you can make modifica tion yourself Ron indicates enlarged crankshaft K&B/Cox 15 will flow approximately 30% air through engine minimum 500 rpm gain test stand Racing tank refueling procedures Several Gone forever nightmare heli-flier dreads stepping 3 foot tenna ripping off front prized chopper just ifs ready fly Base loaded short WHIPANTENNA f iveshidden performance Less 7 ong can mounted project front helicopter inside canopy ts virtually invtsible cZv~ 00R0A54 MODEL PRODUCTS 23961 CRAFTSMAN RD CALABASAS CA 91302 818 992-0195 218 VERNON ROAD GREENVILLE PA 16125 412 588-1321 competitors have written asking prevent damage fuel tank fill tube during hasty pit stop tube occasionally pushed down quick-fill too far rams hole bottom tank Ron Esman Texas Racing contingent found soldering small ring onto neck fuel filler ring prevents fill tube going too far tank Also size ring prevents fuel squirting back pit mans face deflects spray either side aircraft ring can easily fabricated large washer soldered place after measuring length tube enters tank Mouse Racing Al Lidberg Tempe AZ has sent some plans Annie Mouse Racer particular aircraft flies very well has very successful local competition flying area am including plan months column am sure would like further information can write Al Lidberg 614 W Fordham Tempe AZ 85283 St Louis alive well just talked Gary Frost St Louis area indicated both flying field club both excellent health Gary planning early October contest 87 people have written asked what happened St Louis will understand contest schedule once again reinstated major problem Buder Park flying site last summers contest schedule interruption park used horse shows instead model airplanes Gary assures has rectified 1987 fine Midwest site should again scene fine annual meet AMA records Racing received several requests mentioning Racing events being cluded AMA National Records As talk AMA district representatives both VP CL Contest Board please men tion Racing contingent would like have AMA records Racing events am sure voice heard something will done F2C Team Racer drawings have over dozen requests six sets plans Russian TRs. have sent copies everyone requested anyone else might have missed column still have several copies left will happy forward As always comments photographs appreciated John C Ballard 10102 Kimblewick Dr Louisville KY 40223 Charger/Kopski Continued page 84 dont feel comfortable confident sol dering get someone help works Space does permit detailed discussion technical details circuity operation Id like least pass along brief explanation basic idea involved As mentioned above although DC/DC Super Charger fully adjustable may provide stable charge current because set value current part dependent certain conditions external charger modification presented corrects adding internal reference charge current feedback circuit au tomatically adjusts charger operation output current should stray chosen value Referring schematic modified charger output current flows through ohm sampling resistor RL-R2 voltage appearing across resistance directly proportional charge current small circuit-card subassembly contains PNP transistor base-emitter junc tion watches voltage Adjustable divider R3-R4the new current control selects portion R1-R2 voltage application transistor Note R4 rewired original 10K control plus range switch still used adjust desired output current collector transistor con nected original electronics charger control pot origi nally wired effect transistor comes new controlling device original circuit happens because transistor collector will conduct current base emitter junction does So depending setting R4 sampled charge current causes about 06 volts often called VBE Threshold used voltage reference appear base-emitter junction tran sistor collector applies control signal original location adjustment control done way maintain steady output current 158 Model Aviation DC-3 1140 Span$4200 F4U CORSAIR2% Span$3000 ASMS ZERO2% pan$3000 CURTIS P402% Span$3000 AT-S TEXAN24 Span$3000 F8FBEARCAT2% Span$3000 FOKKERDR-127 Tripa$2700 Whip Antenna Gives Hidden Performance Thus some reason chosen value charge current should rise such auto engine started alternator causes auto battery voltage rise transistor control circuit instructs charger electronics lower its output maintain steady charge Similarly some reason charge current should drop such due rising voltage battery being charged lower sampled current sensed transistor re adjusts desired value hap pens quickly quietly automatically graphs show typical charger output current behavior both original modified versions As function other added components resistor R5 prevents exces sive damaging current flowing transistor base R6 Cl C2 Dl perform filtering functions com bined original new electronics work together properly Resistor R7 terminal strip makes up missing pot originally circuit Using modified Super Charger very much like using unmodified version suggest turn current control down minimum select range switch setting correspond number cells being charged Connect charger clips auto battery output cable model battery Turn timer switch fully clockwise set current control knob desired current meter reading Thats Thoughts suggestions Essentially needed information modifying charger given photos captions some additional offerings considering modification Several chargers have modified using information have worked billed effort has made assure satisfactory operationincluding extensive field testing accounts delayed article should clear task beginner also should easy straightforward reasonable skill relevant experience may notice charger current varies whenever operating transmitter brought within close proximity natural consequence radiated signal interfering charger electronicsso dont worry dont either natural consequence using charger assured constant-timed current flights same profile will become remarkably uniform duration particularly noticeable sport aerobatic models Sailplanes absence thermal activity has become routine experience con secutive aerobatic flights having nominal durations about five minutes clock within just few seconds other Finally no doubt have already thought realize other modification will void product .EEEEEEU SEe GLOW FUEL MANUFACTURED WITH THE PUREST FINEST QUALITY INGREDIENTS AVAILABLE * Superior Igniters Improve starting idle acceleration Youll notice power bargain fuels * Special Detergents Promote clean burning prevent residue buildup * Rust Inhibitors Protect engines corrosion After run oil needed engines * Film Strength Additives Increase lubricity provide extra lean run protection * Anti-Wear Additives Help keep engines running peak performance longer * Satisfaction Guaranteed SIG CHAMPION 2-STROKE FUEL FREIGHT FREE SHIPPING ON ORDERS OVER $1500 COLLECT PINTQUART GALLON55 GAL DRUM 0%Nitromethane$315$450$1050$19000 5%Nitromethane$365$525$1250$25800 10%Nitromethane$415$550$1450$32500 15%Nitromethane$430$625$1650$38500 25%Nitromethane$495$750$2095$52000 35%Nitromethane$575$875$2495$66000 SIG PREMIUM4-STROKE FUEL 10%Nitromethane$415$550$1395$29500 15%Nitromethane$425$625$1595$35900 THECHOICE OF CHAMPIONFLYERS over 20 years SIG has blending finest quality model engine fuel available using finest quality ingredients instance Methanol use 995% pure very best grade money can buy also use real 100% pure Nitromethane get full measure youve paid based honest percentage-of-volume method percentage weight SIG fuels con tain 50-50 blend Bakers purest AA Castor Oil new improved Klotz Techniplate Synthetic Racing Oil maximum engine lubrication protection Based experience sincerely believe finest quality fuel can made price dont take word try some judge 1111111 N iuii BROWN JR CAMPBELL COMET COVERITE COX EASY BUILT MODELS ENYA- FAt INE Fox GOLDBERG- GOLDEN AGE REPRO GENE DUBOIS GUILLOW- K&B K&S L R MRC OS MAX PACTRA PECK-POLYMER PERFECT R/N MODELS SEAGLEN SIG STERLING SULLIVAN SUPER TIGRE TAFFINDER TELCO- TOP FLITE- TREXLER WILLIAMS & OTHERS ESTES MODEL ROCKETS Send $100 Cash Check Stamps 44 page tahlold sire DISCOUNT Catalog 900 illostrations osrr 700 Kits choose MAILORDER PIIONEORDER IN STORE PENN VALLEY DOUBT CENTER 137 1 Kain 3t Lanidalmla 19441 September1987 159 TKieeha11 RIC 1db-Bar Glow Plugs Long orOnly $189 Also. Traditional line non-idle bar Glow Plugs Six Types 3 Heat Ranges High Performance Glow Element Blow Proof Seal Only $149 Swanson Associates PO Box 151 Since 7948 Wayne NJ 07470 warranty Just know Good luck charger modifi cation Im sure youll find stable reliable charge current affords well worth small effort cost needed achieve Happy Silent Flying Electrics Please forward comments ques tions SASE please author Bob Kopski 25 West End Dr Lansdale I When responding advertisers mention read about ModelAviation JET ENGINESSALE DYNAJETS $19900 Catalog $500 AL TOmE 4015 Ban Jacjsxto # 404 0 Houston Texas flOO4 p13 4404744 WANNA RACE NARTHFAT ARFA* BEGINNER RACESr Q-500 * FORM-i * FAI Instructions Club Programs informatiot Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVE FRANKLIN MASS 02038 Tel 617 528-4043 203 673 -2000 PA 19446 Parts List Radio Shack PartDescriptionPt No Ri1 ohm 10 watt resistor271 131 R21 ohm 10 watt resistor271 131 R322 K ohm resistor271 1325 R410 Kohmcontrolpotorig inal charger output control R51 K ohm resistor271 1321 R61 K ohm resistor271 1321 R715 K ohm resistor271 1337 Cl1OuF35VTantalum2721434 capacitor C2 22 uF 16 V Tantalum 2721437 capacitor 01 PNPtransistoranyoneof MP52907 M PS3638 2N2907 2N2907A 2N3906 Dl Silicon diode 1N914 1N4148 1 N4454 Miscellaneous PC Holeboard cut from 276 170 Terminal strip made from274 688 Wire Ace RC similar required 3/1 6in inside dia star washer Auto battery clips large 270 344 Six ft white 18-gauge lamp cord optional Solder required EpoxyDevcon 2-Ton white slow cure hardware store Time Three four hours Burt Rutan/Worth Continued page 91 discussion indicated desire part get 1987 Nats Lincoln meet old friends famous modelers After luncheon made firm Burt expected guest honor AMA banquet Wednesday Nats week AMA awards ceremony tended Burt Rutan friend Tonya Simone AMA President Don Lowe Na tional Aeronautic Association Executive Vice President Ev Langworthy AMA Executive Director John Worth Mrs Worth AMA Vice-Presidents Don Krafft District 1 Dave Brown 3 Howard Crispin 4 John Clemens 8 Dick Crowley 9 also AMA member Dave Edmonds HQ staffers Hurst Bowers Joyce Hager Geoff Styles Jeff Troy Vince Mankowski Lou Ward Doug Pratt Special guests Luther Hux wife Dawnthey provided model Voyager luncheon cen terpiece also photos article Postscript Voyager model RC flown time awards ceremony next morningfollow ing advice Burt concerning trim design factorsLuther Hux flew model successfully four times As fullscale design model flies well 276 2023a fitting follow-up evening before 276 2032when Luther said Dick Rutan Jeana Yeager During past years have flying Space Shuttle model AMA air shows Whenever landed everyone cheered watching real 2761122thing know cheers 2761122the model people flew full-scale Shuttle matter pride achieved Americans year fly Voyager model Im looking forward listening cheer CL Regionals/Hazel Continued page 94 As customary least some winning Speed flights posted Fri day Bill Nusz Lancaster CA shook up air bit fastest Class D time meet 19557 mph also turned out fastest official time event Bills ship original built Newton glass fuselage top sheet aluminum wings engine OS65 modified Glen Dye turned Rev-Up 9 x 13 prop uniflow pressure tank juiced 75% nitro fuel youre hot youre hot Bill man aged put up fastest official Jet time Friday well posting 19264 mph Super Burp design Model Avi ation plans #243 Hed reworked DynaJet engine along lines detailed Continued page 166 160 Model Aviation CHAMPION FF KITS Wakefield$44 95 Coupe$25 95* Wake-Up Mulvihill$2450 CHAMPION RUBBER 3/16 & 1/4 widths 042 thick $1195/lb BOx* CATALOG $100 CHAMPION MODEL PRODUCTS 880 Carmen Ct La Verne CA 91750 714 599-3348 Inclades US ddney xu UPSC4I resde,ts add 0% sates tax i UILD YOUR HELl TEST YOUR HELl AIR YOUR H ELI North 7th St ~I1 Lehighton Pa 18235 WRITE OR CALL FOR INFORMA TION ALREADY FLYING BIND NEW TRAINERS WITH RADIO AND ENGNE INSTALLED-OntyS300 FUTABA 4NLw/4S38 SERVOS S2OrTS R/G PARADISE 6089354206 660 KAUMANA Dr HILOHi 96720 PAW DIESELS Englands Finest 049 35 RIC STD S.d $100 list Eric Ciutton 913 Cedar Lane Tuliahoma Tenn 37388 CARBON MAT SAMPLE 2 OR 5 OZ/SO YD SEND $1 00 EACH TO AEROSPACE COMPOSITE PRODUCTS PO Box 16621 Ervine CA 92714
Edition: Model Aviation - 1987/09
Page Numbers: 81, 82, 83, 84, 158, 159, 160
The simple modifications described article will give Astro Model 102 charger consistent output make impervious input voltage fluc tuations allowing charge battery packs driving field EBob Kopski SEVERAL MONTHS AGO regu lar monthly RC Electrics column promised information modification Astro Model 102 DC/DC Super September 1987 81 mop xcup TUTU IOfl9Uf unarge ouro ruiuuuiuu rung ewulun uno larger Oattery clips modified charger looks very much did originally Using white 6-ft lamp cord makes convenientto hook upthe model its visible grass Switching larger clips provides better connection car batterysomething current-hungry chargers should have other mode arent made range switch relabeled Sharpie marking pen read 1-14 lower position 10-22 upperpositlon Above inside original Astro DC/DC charger pencil points originsi component thats re wiredthe controi pot White wire timer meter will replaced resistor pair FiGURE 1 Char OUTPUT CURRENT AW 7 Set Point 4A P 12V Inpi 12 Left graph shows what happens th original modified chargeroutput currents input voitage isvaried Tests included two differentbatterypacksan 8-cell 1 2Ah pack being charged onthe 1-14 cell range a20 cciii 2 Ah pack beingchargedonthe 10-22 cell range smaller pack set up charge 4 amps 12-volt input larger pack set up 3 amps same input voltage input varied up down such might happen starting running car engine easyto see improvement mod makes Right Graph depicts variation charge current tars fixed inputvoitagetothe chargerovera 1 5-minute charge cycle Two different 12 Ah packs testedan 8-cell 20-cell initial charge current time 0 set 4 amps Start Radio Shack terminal strip shown left Cut down shown right bendtheterminalsgO Solder resistor R7 shown carefully driii out mounting lug hois 3/16 Modifications should begin instal lation two 1-ohm 10 watt resistors Ri R2 resistors actually wired parallel form /rohm current-sam pling resistor Both resistors will get hot during operation very important thatthev cooxied aluminum canaL Charger modification easy stall will significantly improve performance already very fine prod uct applications Heres what its about Astro Super Charger may thought fully adjustable voltage converter effect charger can take 12-volt input auto battery change lower higher values done setting range switch adjustable control knob Thus charging pack containing few cells charger set relatively low output voltage pack has cells higher normal 12-volt car battery voltage needed charger adjusted provide Its like having variable auto battery help clear up some confusion about product subject charger 82 Model Aviation Tne terminsi strip assemmy neia piece aytne meisi-tramee inductors mounting screw Position strip clear everything Label wires pot original location can retained Remove wire pot lug nearest front photo solder right-hand lug terminal strip Remove other two wires pot soiderthem left lug terminal strip mix up FIGURE 3 Astro DC-DC Super Charger Modification Schematic Remove knob control pot remove pot front panel Solder three short wiressuch leftover resistor leadsto pot lugs run wIres through proper holes circuit board Keep board snug againstthe pot additional strength route wires through two holes circuit board bringing wire U shape back up through adjacent hole clr cult board Securely solder wire both points goes through board automaticie does sense battery charge condition shut itself off Rather has standard 15-minute timer switch control charge duration perfectly acceptable way doing things fact charging timed charge Therefore modification does change aspect chargers operation However charger also regu lated what modification about regulated sense selected battery charge current inherently stable rather varies both charge condition terminal volt age battery being charged auto battery voltage driving As consequence often necessary keep eye charge current readjust control knob during charging cycle Personally Im used charging stable charge current after seeing well Astro 102 otherwise performed began wonder about modifying September 1987 83 two connectons REPLACE existing wire NOTE All components shown pcholeboard subassembly except Ri R2 panel Ri terminal strip /Ri lOw SOLDER TOSOLDER TO UPPER TERMINAL1L--V\/\J~J ILEFT TERMINAL OF TIMER-SWITCHI P2 lOwJOF AqIETER GREY ORANGER3 22kR4 10k Original Control Pot CW ROTATION Increases Output P51kN TERMINAL STRIP TRANSISTOR QiDETAIL Cl luf35v R6lk YELLOWII II15k WIRE DIODE DlCZ 2Zuf iSvK YELLOW WIRE TO LEFTGREEN WIRE TO ORIGINAL LUG OF ADDED TERMINALCHARGER CIRCUIT BOARD STRIP RiSee photo 8 WIRES FROM ORIGINAL CIRCUIT BOARD--ORIGINALLY CONNECTED TO CONTROL POT simple circuIt addition needed stabilize charge current limited number re quired parts makes easy task some soldering experIence very important work carefully correctly because mistake could damage charger FIGURE 4 Astro DC-DC Super Charger Modification uit Board Pictorial SPECIAL NOTE LEADS VARY--SO BE SURE YOUR TRANSISTOR CEB LEADS GD TO CORRECT LOCATIONS COLLECTOR GREEN WIRE TO OIARGER CKT BOARD YELLOW WIRE TO TERMINAL STRIP EMITTER BASE P3 THIS PICTORIAL IS TOP VIEW R4 control pot 9 QI JtLr7JDlCi//R5 JORANGE WIRE TO TIMERSWITCH ALL DOTTED VERTICAL LINES INDICATE FOIL CONNECTORS ON CIRCUIT BOARD SPECIAL NOTE PC-HOLE BOARD MUST BE CUT TO SIZE WITH SHOLE CONDUCTOR PATTERN LOCATED BETWEEN THESE ARROWS BOARD IS 17 HOLES WIRE TO PANEL METER Almost circuit modification components assembled small piece circuit board wire leads identif led color used original assembly may change colors change wiring locationsbe sure what doingi Attach green wire directly original charger circuit board underneath large metal-framed inductor wire colors mentioned throughout procedure reference four distInct colors could usedbut dont mix up locational Install other components nns circume ~ardasshownintheassembiydrawing careful get capacitor diode polarities correct Make sure transistor leads inthe approprIate iocationssomett5n515t0r choices have leads different locations Connect 6-in lead-out wires shown Standard RC wire Ace RC okay include output current stabilization article result pursuing idea simple additional circuitry described herein makes selected charge current much stable Once set have readjust charge value over 15-minute timer period best part about charging can done auto engine running can arrive field ready fly See Model Avi ation March July 1985 Just re member attempt charging batteries driving car modi fication could disastrous since input voltage variation occurs car runmng causes similar tremendous vari ation charger output current course everything else life somethings just gotta wrong thing sounds goodright Yup four disadvantages associated modification First circuit modification reduces two maximum number cells could otherwise charged cause added circuitry uses some available charger output voltage makes unavailable battery being charged Second modified charger uses slight ly current auto battery runs somewhat hotter result charger output current flowing through added sampling resistor R1-R2 have found no ill effects because Third trickle charge now unadjust able Ordinarily small trickle charge current can set charger timer off As rule never trickle charge anyway besides coarse scale meter doesnt permit readable values such low currents begin withso doesnt bother fourth disadvantage drawback under particular set circum stances Ill call fourth difference modification output current charger cannot turned completely zero lowest output about 12 amps control knob adjusts upward woukl disadvantage wanted charge very small cells such 250 mAh smaller Now feel youd like have described advantages can somehow make through life disadvantages read See works easy modiir Astro DC/DC Super Charger added circuItry charger modi fication consists assembling small circuit board usjng Radio Shack parts installing new subassembly DC/DC Super Charger changes original charger minimal re versibleso should ever want change back can original charger parts used onethe control pot wires rewired have follow sketches photos exactly work carefully Continued page 158 84 Model Aviation FIGURE 5 Astro DC-DC Super Charger Modification Misc Pictorial Details GREEN WIRE SI LITE t1Ii LAD IBITTED ORIGINAL POT WIRING SOLID RE-cONNECTIONS REItJVE add RI-R2 R2 WI RE REAR VIEW Left Pay particularattentlon rerouting wires original potentiometer mistake will cause extensive damage original charger circuit Right Parailel resistors Ri R2 replace wire orIgInally connecting panel meter timer switch Use short lengths 1 8-gauge lamp cord extend resistor leads required Ri R2 must epoxy-giued aiuminum panel heat-sink cooling purposes ORIGINAL CIRCUIT BOARD wider inductor V 0 inside completed sin u uiirur mmmi resistor ana wire going ins pilOt light should removed since InC trickle-charge circuit no longer functions original Reinstalithe control potwlth its newcircultboard attached intotheoriginal panel location Position circuit board clears everything Tighten pot mounting nut Reinstall control knob making sure pot turned fully CCW pointer t 7 n,lnk Trim fin. wire fr irnh -"er appropriate destinations PRACTICAL SIZED GIANT Order Canopies Available Plans sent Post-Paid within USA Send 5Oe Full Catalog Balsa Nick Ziroli 29 EdMar Dr Smithiown NY 11787 USA MODELS NICK ZIROLI Jets too Plans RK-20 RK-740 Ducted Fans Phantom38 span$1000 Viggen32 span$1000 F-1538 span$1000 Plan canopy$1500 516-234-5038 enclosing some photos modifications K&B 15 definitely improve ground rpm engine resulting airspeed As can see photograph stock crank left crank right has enlarged extra meat has taken out shaft area addition venturi has enlarged some 015 second photograph shows enlarge ment venturi well giving view back crank can see enlarged hole extra meat removed up near timing area particular cranks close around 620 after top dead center ATDC Ron Youngs Performance Engines will rework cranks you can make modifica tion yourself Ron indicates enlarged crankshaft K&B/Cox 15 will flow approximately 30% air through engine minimum 500 rpm gain test stand Racing tank refueling procedures Several Gone forever nightmare heli-flier dreads stepping 3 foot tenna ripping off front prized chopper just ifs ready fly Base loaded short WHIPANTENNA f iveshidden performance Less 7 ong can mounted project front helicopter inside canopy ts virtually invtsible cZv~ 00R0A54 MODEL PRODUCTS 23961 CRAFTSMAN RD CALABASAS CA 91302 818 992-0195 218 VERNON ROAD GREENVILLE PA 16125 412 588-1321 competitors have written asking prevent damage fuel tank fill tube during hasty pit stop tube occasionally pushed down quick-fill too far rams hole bottom tank Ron Esman Texas Racing contingent found soldering small ring onto neck fuel filler ring prevents fill tube going too far tank Also size ring prevents fuel squirting back pit mans face deflects spray either side aircraft ring can easily fabricated large washer soldered place after measuring length tube enters tank Mouse Racing Al Lidberg Tempe AZ has sent some plans Annie Mouse Racer particular aircraft flies very well has very successful local competition flying area am including plan months column am sure would like further information can write Al Lidberg 614 W Fordham Tempe AZ 85283 St Louis alive well just talked Gary Frost St Louis area indicated both flying field club both excellent health Gary planning early October contest 87 people have written asked what happened St Louis will understand contest schedule once again reinstated major problem Buder Park flying site last summers contest schedule interruption park used horse shows instead model airplanes Gary assures has rectified 1987 fine Midwest site should again scene fine annual meet AMA records Racing received several requests mentioning Racing events being cluded AMA National Records As talk AMA district representatives both VP CL Contest Board please men tion Racing contingent would like have AMA records Racing events am sure voice heard something will done F2C Team Racer drawings have over dozen requests six sets plans Russian TRs. have sent copies everyone requested anyone else might have missed column still have several copies left will happy forward As always comments photographs appreciated John C Ballard 10102 Kimblewick Dr Louisville KY 40223 Charger/Kopski Continued page 84 dont feel comfortable confident sol dering get someone help works Space does permit detailed discussion technical details circuity operation Id like least pass along brief explanation basic idea involved As mentioned above although DC/DC Super Charger fully adjustable may provide stable charge current because set value current part dependent certain conditions external charger modification presented corrects adding internal reference charge current feedback circuit au tomatically adjusts charger operation output current should stray chosen value Referring schematic modified charger output current flows through ohm sampling resistor RL-R2 voltage appearing across resistance directly proportional charge current small circuit-card subassembly contains PNP transistor base-emitter junc tion watches voltage Adjustable divider R3-R4the new current control selects portion R1-R2 voltage application transistor Note R4 rewired original 10K control plus range switch still used adjust desired output current collector transistor con nected original electronics charger control pot origi nally wired effect transistor comes new controlling device original circuit happens because transistor collector will conduct current base emitter junction does So depending setting R4 sampled charge current causes about 06 volts often called VBE Threshold used voltage reference appear base-emitter junction tran sistor collector applies control signal original location adjustment control done way maintain steady output current 158 Model Aviation DC-3 1140 Span$4200 F4U CORSAIR2% Span$3000 ASMS ZERO2% pan$3000 CURTIS P402% Span$3000 AT-S TEXAN24 Span$3000 F8FBEARCAT2% Span$3000 FOKKERDR-127 Tripa$2700 Whip Antenna Gives Hidden Performance Thus some reason chosen value charge current should rise such auto engine started alternator causes auto battery voltage rise transistor control circuit instructs charger electronics lower its output maintain steady charge Similarly some reason charge current should drop such due rising voltage battery being charged lower sampled current sensed transistor re adjusts desired value hap pens quickly quietly automatically graphs show typical charger output current behavior both original modified versions As function other added components resistor R5 prevents exces sive damaging current flowing transistor base R6 Cl C2 Dl perform filtering functions com bined original new electronics work together properly Resistor R7 terminal strip makes up missing pot originally circuit Using modified Super Charger very much like using unmodified version suggest turn current control down minimum select range switch setting correspond number cells being charged Connect charger clips auto battery output cable model battery Turn timer switch fully clockwise set current control knob desired current meter reading Thats Thoughts suggestions Essentially needed information modifying charger given photos captions some additional offerings considering modification Several chargers have modified using information have worked billed effort has made assure satisfactory operationincluding extensive field testing accounts delayed article should clear task beginner also should easy straightforward reasonable skill relevant experience may notice charger current varies whenever operating transmitter brought within close proximity natural consequence radiated signal interfering charger electronicsso dont worry dont either natural consequence using charger assured constant-timed current flights same profile will become remarkably uniform duration particularly noticeable sport aerobatic models Sailplanes absence thermal activity has become routine experience con secutive aerobatic flights having nominal durations about five minutes clock within just few seconds other Finally no doubt have already thought realize other modification will void product .EEEEEEU SEe GLOW FUEL MANUFACTURED WITH THE PUREST FINEST QUALITY INGREDIENTS AVAILABLE * Superior Igniters Improve starting idle acceleration Youll notice power bargain fuels * Special Detergents Promote clean burning prevent residue buildup * Rust Inhibitors Protect engines corrosion After run oil needed engines * Film Strength Additives Increase lubricity provide extra lean run protection * Anti-Wear Additives Help keep engines running peak performance longer * Satisfaction Guaranteed SIG CHAMPION 2-STROKE FUEL FREIGHT FREE SHIPPING ON ORDERS OVER $1500 COLLECT PINTQUART GALLON55 GAL DRUM 0%Nitromethane$315$450$1050$19000 5%Nitromethane$365$525$1250$25800 10%Nitromethane$415$550$1450$32500 15%Nitromethane$430$625$1650$38500 25%Nitromethane$495$750$2095$52000 35%Nitromethane$575$875$2495$66000 SIG PREMIUM4-STROKE FUEL 10%Nitromethane$415$550$1395$29500 15%Nitromethane$425$625$1595$35900 THECHOICE OF CHAMPIONFLYERS over 20 years SIG has blending finest quality model engine fuel available using finest quality ingredients instance Methanol use 995% pure very best grade money can buy also use real 100% pure Nitromethane get full measure youve paid based honest percentage-of-volume method percentage weight SIG fuels con tain 50-50 blend Bakers purest AA Castor Oil new improved Klotz Techniplate Synthetic Racing Oil maximum engine lubrication protection Based experience sincerely believe finest quality fuel can made price dont take word try some judge 1111111 N iuii BROWN JR CAMPBELL COMET COVERITE COX EASY BUILT MODELS ENYA- FAt INE Fox GOLDBERG- GOLDEN AGE REPRO GENE DUBOIS GUILLOW- K&B K&S L R MRC OS MAX PACTRA PECK-POLYMER PERFECT R/N MODELS SEAGLEN SIG STERLING SULLIVAN SUPER TIGRE TAFFINDER TELCO- TOP FLITE- TREXLER WILLIAMS & OTHERS ESTES MODEL ROCKETS Send $100 Cash Check Stamps 44 page tahlold sire DISCOUNT Catalog 900 illostrations osrr 700 Kits choose MAILORDER PIIONEORDER IN STORE PENN VALLEY DOUBT CENTER 137 1 Kain 3t Lanidalmla 19441 September1987 159 TKieeha11 RIC 1db-Bar Glow Plugs Long orOnly $189 Also. Traditional line non-idle bar Glow Plugs Six Types 3 Heat Ranges High Performance Glow Element Blow Proof Seal Only $149 Swanson Associates PO Box 151 Since 7948 Wayne NJ 07470 warranty Just know Good luck charger modifi cation Im sure youll find stable reliable charge current affords well worth small effort cost needed achieve Happy Silent Flying Electrics Please forward comments ques tions SASE please author Bob Kopski 25 West End Dr Lansdale I When responding advertisers mention read about ModelAviation JET ENGINESSALE DYNAJETS $19900 Catalog $500 AL TOmE 4015 Ban Jacjsxto # 404 0 Houston Texas flOO4 p13 4404744 WANNA RACE NARTHFAT ARFA* BEGINNER RACESr Q-500 * FORM-i * FAI Instructions Club Programs informatiot Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVE FRANKLIN MASS 02038 Tel 617 528-4043 203 673 -2000 PA 19446 Parts List Radio Shack PartDescriptionPt No Ri1 ohm 10 watt resistor271 131 R21 ohm 10 watt resistor271 131 R322 K ohm resistor271 1325 R410 Kohmcontrolpotorig inal charger output control R51 K ohm resistor271 1321 R61 K ohm resistor271 1321 R715 K ohm resistor271 1337 Cl1OuF35VTantalum2721434 capacitor C2 22 uF 16 V Tantalum 2721437 capacitor 01 PNPtransistoranyoneof MP52907 M PS3638 2N2907 2N2907A 2N3906 Dl Silicon diode 1N914 1N4148 1 N4454 Miscellaneous PC Holeboard cut from 276 170 Terminal strip made from274 688 Wire Ace RC similar required 3/1 6in inside dia star washer Auto battery clips large 270 344 Six ft white 18-gauge lamp cord optional Solder required EpoxyDevcon 2-Ton white slow cure hardware store Time Three four hours Burt Rutan/Worth Continued page 91 discussion indicated desire part get 1987 Nats Lincoln meet old friends famous modelers After luncheon made firm Burt expected guest honor AMA banquet Wednesday Nats week AMA awards ceremony tended Burt Rutan friend Tonya Simone AMA President Don Lowe Na tional Aeronautic Association Executive Vice President Ev Langworthy AMA Executive Director John Worth Mrs Worth AMA Vice-Presidents Don Krafft District 1 Dave Brown 3 Howard Crispin 4 John Clemens 8 Dick Crowley 9 also AMA member Dave Edmonds HQ staffers Hurst Bowers Joyce Hager Geoff Styles Jeff Troy Vince Mankowski Lou Ward Doug Pratt Special guests Luther Hux wife Dawnthey provided model Voyager luncheon cen terpiece also photos article Postscript Voyager model RC flown time awards ceremony next morningfollow ing advice Burt concerning trim design factorsLuther Hux flew model successfully four times As fullscale design model flies well 276 2023a fitting follow-up evening before 276 2032when Luther said Dick Rutan Jeana Yeager During past years have flying Space Shuttle model AMA air shows Whenever landed everyone cheered watching real 2761122thing know cheers 2761122the model people flew full-scale Shuttle matter pride achieved Americans year fly Voyager model Im looking forward listening cheer CL Regionals/Hazel Continued page 94 As customary least some winning Speed flights posted Fri day Bill Nusz Lancaster CA shook up air bit fastest Class D time meet 19557 mph also turned out fastest official time event Bills ship original built Newton glass fuselage top sheet aluminum wings engine OS65 modified Glen Dye turned Rev-Up 9 x 13 prop uniflow pressure tank juiced 75% nitro fuel youre hot youre hot Bill man aged put up fastest official Jet time Friday well posting 19264 mph Super Burp design Model Avi ation plans #243 Hed reworked DynaJet engine along lines detailed Continued page 166 160 Model Aviation CHAMPION FF KITS Wakefield$44 95 Coupe$25 95* Wake-Up Mulvihill$2450 CHAMPION RUBBER 3/16 & 1/4 widths 042 thick $1195/lb BOx* CATALOG $100 CHAMPION MODEL PRODUCTS 880 Carmen Ct La Verne CA 91750 714 599-3348 Inclades US ddney xu UPSC4I resde,ts add 0% sates tax i UILD YOUR HELl TEST YOUR HELl AIR YOUR H ELI North 7th St ~I1 Lehighton Pa 18235 WRITE OR CALL FOR INFORMA TION ALREADY FLYING BIND NEW TRAINERS WITH RADIO AND ENGNE INSTALLED-OntyS300 FUTABA 4NLw/4S38 SERVOS S2OrTS R/G PARADISE 6089354206 660 KAUMANA Dr HILOHi 96720 PAW DIESELS Englands Finest 049 35 RIC STD S.d $100 list Eric Ciutton 913 Cedar Lane Tuliahoma Tenn 37388 CARBON MAT SAMPLE 2 OR 5 OZ/SO YD SEND $1 00 EACH TO AEROSPACE COMPOSITE PRODUCTS PO Box 16621 Ervine CA 92714
Edition: Model Aviation - 1987/09
Page Numbers: 81, 82, 83, 84, 158, 159, 160
The simple modifications described article will give Astro Model 102 charger consistent output make impervious input voltage fluc tuations allowing charge battery packs driving field EBob Kopski SEVERAL MONTHS AGO regu lar monthly RC Electrics column promised information modification Astro Model 102 DC/DC Super September 1987 81 mop xcup TUTU IOfl9Uf unarge ouro ruiuuuiuu rung ewulun uno larger Oattery clips modified charger looks very much did originally Using white 6-ft lamp cord makes convenientto hook upthe model its visible grass Switching larger clips provides better connection car batterysomething current-hungry chargers should have other mode arent made range switch relabeled Sharpie marking pen read 1-14 lower position 10-22 upperpositlon Above inside original Astro DC/DC charger pencil points originsi component thats re wiredthe controi pot White wire timer meter will replaced resistor pair FiGURE 1 Char OUTPUT CURRENT AW 7 Set Point 4A P 12V Inpi 12 Left graph shows what happens th original modified chargeroutput currents input voitage isvaried Tests included two differentbatterypacksan 8-cell 1 2Ah pack being charged onthe 1-14 cell range a20 cciii 2 Ah pack beingchargedonthe 10-22 cell range smaller pack set up charge 4 amps 12-volt input larger pack set up 3 amps same input voltage input varied up down such might happen starting running car engine easyto see improvement mod makes Right Graph depicts variation charge current tars fixed inputvoitagetothe chargerovera 1 5-minute charge cycle Two different 12 Ah packs testedan 8-cell 20-cell initial charge current time 0 set 4 amps Start Radio Shack terminal strip shown left Cut down shown right bendtheterminalsgO Solder resistor R7 shown carefully driii out mounting lug hois 3/16 Modifications should begin instal lation two 1-ohm 10 watt resistors Ri R2 resistors actually wired parallel form /rohm current-sam pling resistor Both resistors will get hot during operation very important thatthev cooxied aluminum canaL Charger modification easy stall will significantly improve performance already very fine prod uct applications Heres what its about Astro Super Charger may thought fully adjustable voltage converter effect charger can take 12-volt input auto battery change lower higher values done setting range switch adjustable control knob Thus charging pack containing few cells charger set relatively low output voltage pack has cells higher normal 12-volt car battery voltage needed charger adjusted provide Its like having variable auto battery help clear up some confusion about product subject charger 82 Model Aviation Tne terminsi strip assemmy neia piece aytne meisi-tramee inductors mounting screw Position strip clear everything Label wires pot original location can retained Remove wire pot lug nearest front photo solder right-hand lug terminal strip Remove other two wires pot soiderthem left lug terminal strip mix up FIGURE 3 Astro DC-DC Super Charger Modification Schematic Remove knob control pot remove pot front panel Solder three short wiressuch leftover resistor leadsto pot lugs run wIres through proper holes circuit board Keep board snug againstthe pot additional strength route wires through two holes circuit board bringing wire U shape back up through adjacent hole clr cult board Securely solder wire both points goes through board automaticie does sense battery charge condition shut itself off Rather has standard 15-minute timer switch control charge duration perfectly acceptable way doing things fact charging timed charge Therefore modification does change aspect chargers operation However charger also regu lated what modification about regulated sense selected battery charge current inherently stable rather varies both charge condition terminal volt age battery being charged auto battery voltage driving As consequence often necessary keep eye charge current readjust control knob during charging cycle Personally Im used charging stable charge current after seeing well Astro 102 otherwise performed began wonder about modifying September 1987 83 two connectons REPLACE existing wire NOTE All components shown pcholeboard subassembly except Ri R2 panel Ri terminal strip /Ri lOw SOLDER TOSOLDER TO UPPER TERMINAL1L--V\/\J~J ILEFT TERMINAL OF TIMER-SWITCHI P2 lOwJOF AqIETER GREY ORANGER3 22kR4 10k Original Control Pot CW ROTATION Increases Output P51kN TERMINAL STRIP TRANSISTOR QiDETAIL Cl luf35v R6lk YELLOWII II15k WIRE DIODE DlCZ 2Zuf iSvK YELLOW WIRE TO LEFTGREEN WIRE TO ORIGINAL LUG OF ADDED TERMINALCHARGER CIRCUIT BOARD STRIP RiSee photo 8 WIRES FROM ORIGINAL CIRCUIT BOARD--ORIGINALLY CONNECTED TO CONTROL POT simple circuIt addition needed stabilize charge current limited number re quired parts makes easy task some soldering experIence very important work carefully correctly because mistake could damage charger FIGURE 4 Astro DC-DC Super Charger Modification uit Board Pictorial SPECIAL NOTE LEADS VARY--SO BE SURE YOUR TRANSISTOR CEB LEADS GD TO CORRECT LOCATIONS COLLECTOR GREEN WIRE TO OIARGER CKT BOARD YELLOW WIRE TO TERMINAL STRIP EMITTER BASE P3 THIS PICTORIAL IS TOP VIEW R4 control pot 9 QI JtLr7JDlCi//R5 JORANGE WIRE TO TIMERSWITCH ALL DOTTED VERTICAL LINES INDICATE FOIL CONNECTORS ON CIRCUIT BOARD SPECIAL NOTE PC-HOLE BOARD MUST BE CUT TO SIZE WITH SHOLE CONDUCTOR PATTERN LOCATED BETWEEN THESE ARROWS BOARD IS 17 HOLES WIRE TO PANEL METER Almost circuit modification components assembled small piece circuit board wire leads identif led color used original assembly may change colors change wiring locationsbe sure what doingi Attach green wire directly original charger circuit board underneath large metal-framed inductor wire colors mentioned throughout procedure reference four distInct colors could usedbut dont mix up locational Install other components nns circume ~ardasshownintheassembiydrawing careful get capacitor diode polarities correct Make sure transistor leads inthe approprIate iocationssomett5n515t0r choices have leads different locations Connect 6-in lead-out wires shown Standard RC wire Ace RC okay include output current stabilization article result pursuing idea simple additional circuitry described herein makes selected charge current much stable Once set have readjust charge value over 15-minute timer period best part about charging can done auto engine running can arrive field ready fly See Model Avi ation March July 1985 Just re member attempt charging batteries driving car modi fication could disastrous since input voltage variation occurs car runmng causes similar tremendous vari ation charger output current course everything else life somethings just gotta wrong thing sounds goodright Yup four disadvantages associated modification First circuit modification reduces two maximum number cells could otherwise charged cause added circuitry uses some available charger output voltage makes unavailable battery being charged Second modified charger uses slight ly current auto battery runs somewhat hotter result charger output current flowing through added sampling resistor R1-R2 have found no ill effects because Third trickle charge now unadjust able Ordinarily small trickle charge current can set charger timer off As rule never trickle charge anyway besides coarse scale meter doesnt permit readable values such low currents begin withso doesnt bother fourth disadvantage drawback under particular set circum stances Ill call fourth difference modification output current charger cannot turned completely zero lowest output about 12 amps control knob adjusts upward woukl disadvantage wanted charge very small cells such 250 mAh smaller Now feel youd like have described advantages can somehow make through life disadvantages read See works easy modiir Astro DC/DC Super Charger added circuItry charger modi fication consists assembling small circuit board usjng Radio Shack parts installing new subassembly DC/DC Super Charger changes original charger minimal re versibleso should ever want change back can original charger parts used onethe control pot wires rewired have follow sketches photos exactly work carefully Continued page 158 84 Model Aviation FIGURE 5 Astro DC-DC Super Charger Modification Misc Pictorial Details GREEN WIRE SI LITE t1Ii LAD IBITTED ORIGINAL POT WIRING SOLID RE-cONNECTIONS REItJVE add RI-R2 R2 WI RE REAR VIEW Left Pay particularattentlon rerouting wires original potentiometer mistake will cause extensive damage original charger circuit Right Parailel resistors Ri R2 replace wire orIgInally connecting panel meter timer switch Use short lengths 1 8-gauge lamp cord extend resistor leads required Ri R2 must epoxy-giued aiuminum panel heat-sink cooling purposes ORIGINAL CIRCUIT BOARD wider inductor V 0 inside completed sin u uiirur mmmi resistor ana wire going ins pilOt light should removed since InC trickle-charge circuit no longer functions original Reinstalithe control potwlth its newcircultboard attached intotheoriginal panel location Position circuit board clears everything Tighten pot mounting nut Reinstall control knob making sure pot turned fully CCW pointer t 7 n,lnk Trim fin. wire fr irnh -"er appropriate destinations PRACTICAL SIZED GIANT Order Canopies Available Plans sent Post-Paid within USA Send 5Oe Full Catalog Balsa Nick Ziroli 29 EdMar Dr Smithiown NY 11787 USA MODELS NICK ZIROLI Jets too Plans RK-20 RK-740 Ducted Fans Phantom38 span$1000 Viggen32 span$1000 F-1538 span$1000 Plan canopy$1500 516-234-5038 enclosing some photos modifications K&B 15 definitely improve ground rpm engine resulting airspeed As can see photograph stock crank left crank right has enlarged extra meat has taken out shaft area addition venturi has enlarged some 015 second photograph shows enlarge ment venturi well giving view back crank can see enlarged hole extra meat removed up near timing area particular cranks close around 620 after top dead center ATDC Ron Youngs Performance Engines will rework cranks you can make modifica tion yourself Ron indicates enlarged crankshaft K&B/Cox 15 will flow approximately 30% air through engine minimum 500 rpm gain test stand Racing tank refueling procedures Several Gone forever nightmare heli-flier dreads stepping 3 foot tenna ripping off front prized chopper just ifs ready fly Base loaded short WHIPANTENNA f iveshidden performance Less 7 ong can mounted project front helicopter inside canopy ts virtually invtsible cZv~ 00R0A54 MODEL PRODUCTS 23961 CRAFTSMAN RD CALABASAS CA 91302 818 992-0195 218 VERNON ROAD GREENVILLE PA 16125 412 588-1321 competitors have written asking prevent damage fuel tank fill tube during hasty pit stop tube occasionally pushed down quick-fill too far rams hole bottom tank Ron Esman Texas Racing contingent found soldering small ring onto neck fuel filler ring prevents fill tube going too far tank Also size ring prevents fuel squirting back pit mans face deflects spray either side aircraft ring can easily fabricated large washer soldered place after measuring length tube enters tank Mouse Racing Al Lidberg Tempe AZ has sent some plans Annie Mouse Racer particular aircraft flies very well has very successful local competition flying area am including plan months column am sure would like further information can write Al Lidberg 614 W Fordham Tempe AZ 85283 St Louis alive well just talked Gary Frost St Louis area indicated both flying field club both excellent health Gary planning early October contest 87 people have written asked what happened St Louis will understand contest schedule once again reinstated major problem Buder Park flying site last summers contest schedule interruption park used horse shows instead model airplanes Gary assures has rectified 1987 fine Midwest site should again scene fine annual meet AMA records Racing received several requests mentioning Racing events being cluded AMA National Records As talk AMA district representatives both VP CL Contest Board please men tion Racing contingent would like have AMA records Racing events am sure voice heard something will done F2C Team Racer drawings have over dozen requests six sets plans Russian TRs. have sent copies everyone requested anyone else might have missed column still have several copies left will happy forward As always comments photographs appreciated John C Ballard 10102 Kimblewick Dr Louisville KY 40223 Charger/Kopski Continued page 84 dont feel comfortable confident sol dering get someone help works Space does permit detailed discussion technical details circuity operation Id like least pass along brief explanation basic idea involved As mentioned above although DC/DC Super Charger fully adjustable may provide stable charge current because set value current part dependent certain conditions external charger modification presented corrects adding internal reference charge current feedback circuit au tomatically adjusts charger operation output current should stray chosen value Referring schematic modified charger output current flows through ohm sampling resistor RL-R2 voltage appearing across resistance directly proportional charge current small circuit-card subassembly contains PNP transistor base-emitter junc tion watches voltage Adjustable divider R3-R4the new current control selects portion R1-R2 voltage application transistor Note R4 rewired original 10K control plus range switch still used adjust desired output current collector transistor con nected original electronics charger control pot origi nally wired effect transistor comes new controlling device original circuit happens because transistor collector will conduct current base emitter junction does So depending setting R4 sampled charge current causes about 06 volts often called VBE Threshold used voltage reference appear base-emitter junction tran sistor collector applies control signal original location adjustment control done way maintain steady output current 158 Model Aviation DC-3 1140 Span$4200 F4U CORSAIR2% Span$3000 ASMS ZERO2% pan$3000 CURTIS P402% Span$3000 AT-S TEXAN24 Span$3000 F8FBEARCAT2% Span$3000 FOKKERDR-127 Tripa$2700 Whip Antenna Gives Hidden Performance Thus some reason chosen value charge current should rise such auto engine started alternator causes auto battery voltage rise transistor control circuit instructs charger electronics lower its output maintain steady charge Similarly some reason charge current should drop such due rising voltage battery being charged lower sampled current sensed transistor re adjusts desired value hap pens quickly quietly automatically graphs show typical charger output current behavior both original modified versions As function other added components resistor R5 prevents exces sive damaging current flowing transistor base R6 Cl C2 Dl perform filtering functions com bined original new electronics work together properly Resistor R7 terminal strip makes up missing pot originally circuit Using modified Super Charger very much like using unmodified version suggest turn current control down minimum select range switch setting correspond number cells being charged Connect charger clips auto battery output cable model battery Turn timer switch fully clockwise set current control knob desired current meter reading Thats Thoughts suggestions Essentially needed information modifying charger given photos captions some additional offerings considering modification Several chargers have modified using information have worked billed effort has made assure satisfactory operationincluding extensive field testing accounts delayed article should clear task beginner also should easy straightforward reasonable skill relevant experience may notice charger current varies whenever operating transmitter brought within close proximity natural consequence radiated signal interfering charger electronicsso dont worry dont either natural consequence using charger assured constant-timed current flights same profile will become remarkably uniform duration particularly noticeable sport aerobatic models Sailplanes absence thermal activity has become routine experience con secutive aerobatic flights having nominal durations about five minutes clock within just few seconds other Finally no doubt have already thought realize other modification will void product .EEEEEEU SEe GLOW FUEL MANUFACTURED WITH THE PUREST FINEST QUALITY INGREDIENTS AVAILABLE * Superior Igniters Improve starting idle acceleration Youll notice power bargain fuels * Special Detergents Promote clean burning prevent residue buildup * Rust Inhibitors Protect engines corrosion After run oil needed engines * Film Strength Additives Increase lubricity provide extra lean run protection * Anti-Wear Additives Help keep engines running peak performance longer * Satisfaction Guaranteed SIG CHAMPION 2-STROKE FUEL FREIGHT FREE SHIPPING ON ORDERS OVER $1500 COLLECT PINTQUART GALLON55 GAL DRUM 0%Nitromethane$315$450$1050$19000 5%Nitromethane$365$525$1250$25800 10%Nitromethane$415$550$1450$32500 15%Nitromethane$430$625$1650$38500 25%Nitromethane$495$750$2095$52000 35%Nitromethane$575$875$2495$66000 SIG PREMIUM4-STROKE FUEL 10%Nitromethane$415$550$1395$29500 15%Nitromethane$425$625$1595$35900 THECHOICE OF CHAMPIONFLYERS over 20 years SIG has blending finest quality model engine fuel available using finest quality ingredients instance Methanol use 995% pure very best grade money can buy also use real 100% pure Nitromethane get full measure youve paid based honest percentage-of-volume method percentage weight SIG fuels con tain 50-50 blend Bakers purest AA Castor Oil new improved Klotz Techniplate Synthetic Racing Oil maximum engine lubrication protection Based experience sincerely believe finest quality fuel can made price dont take word try some judge 1111111 N iuii BROWN JR CAMPBELL COMET COVERITE COX EASY BUILT MODELS ENYA- FAt INE Fox GOLDBERG- GOLDEN AGE REPRO GENE DUBOIS GUILLOW- K&B K&S L R MRC OS MAX PACTRA PECK-POLYMER PERFECT R/N MODELS SEAGLEN SIG STERLING SULLIVAN SUPER TIGRE TAFFINDER TELCO- TOP FLITE- TREXLER WILLIAMS & OTHERS ESTES MODEL ROCKETS Send $100 Cash Check Stamps 44 page tahlold sire DISCOUNT Catalog 900 illostrations osrr 700 Kits choose MAILORDER PIIONEORDER IN STORE PENN VALLEY DOUBT CENTER 137 1 Kain 3t Lanidalmla 19441 September1987 159 TKieeha11 RIC 1db-Bar Glow Plugs Long orOnly $189 Also. Traditional line non-idle bar Glow Plugs Six Types 3 Heat Ranges High Performance Glow Element Blow Proof Seal Only $149 Swanson Associates PO Box 151 Since 7948 Wayne NJ 07470 warranty Just know Good luck charger modifi cation Im sure youll find stable reliable charge current affords well worth small effort cost needed achieve Happy Silent Flying Electrics Please forward comments ques tions SASE please author Bob Kopski 25 West End Dr Lansdale I When responding advertisers mention read about ModelAviation JET ENGINESSALE DYNAJETS $19900 Catalog $500 AL TOmE 4015 Ban Jacjsxto # 404 0 Houston Texas flOO4 p13 4404744 WANNA RACE NARTHFAT ARFA* BEGINNER RACESr Q-500 * FORM-i * FAI Instructions Club Programs informatiot Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVE FRANKLIN MASS 02038 Tel 617 528-4043 203 673 -2000 PA 19446 Parts List Radio Shack PartDescriptionPt No Ri1 ohm 10 watt resistor271 131 R21 ohm 10 watt resistor271 131 R322 K ohm resistor271 1325 R410 Kohmcontrolpotorig inal charger output control R51 K ohm resistor271 1321 R61 K ohm resistor271 1321 R715 K ohm resistor271 1337 Cl1OuF35VTantalum2721434 capacitor C2 22 uF 16 V Tantalum 2721437 capacitor 01 PNPtransistoranyoneof MP52907 M PS3638 2N2907 2N2907A 2N3906 Dl Silicon diode 1N914 1N4148 1 N4454 Miscellaneous PC Holeboard cut from 276 170 Terminal strip made from274 688 Wire Ace RC similar required 3/1 6in inside dia star washer Auto battery clips large 270 344 Six ft white 18-gauge lamp cord optional Solder required EpoxyDevcon 2-Ton white slow cure hardware store Time Three four hours Burt Rutan/Worth Continued page 91 discussion indicated desire part get 1987 Nats Lincoln meet old friends famous modelers After luncheon made firm Burt expected guest honor AMA banquet Wednesday Nats week AMA awards ceremony tended Burt Rutan friend Tonya Simone AMA President Don Lowe Na tional Aeronautic Association Executive Vice President Ev Langworthy AMA Executive Director John Worth Mrs Worth AMA Vice-Presidents Don Krafft District 1 Dave Brown 3 Howard Crispin 4 John Clemens 8 Dick Crowley 9 also AMA member Dave Edmonds HQ staffers Hurst Bowers Joyce Hager Geoff Styles Jeff Troy Vince Mankowski Lou Ward Doug Pratt Special guests Luther Hux wife Dawnthey provided model Voyager luncheon cen terpiece also photos article Postscript Voyager model RC flown time awards ceremony next morningfollow ing advice Burt concerning trim design factorsLuther Hux flew model successfully four times As fullscale design model flies well 276 2023a fitting follow-up evening before 276 2032when Luther said Dick Rutan Jeana Yeager During past years have flying Space Shuttle model AMA air shows Whenever landed everyone cheered watching real 2761122thing know cheers 2761122the model people flew full-scale Shuttle matter pride achieved Americans year fly Voyager model Im looking forward listening cheer CL Regionals/Hazel Continued page 94 As customary least some winning Speed flights posted Fri day Bill Nusz Lancaster CA shook up air bit fastest Class D time meet 19557 mph also turned out fastest official time event Bills ship original built Newton glass fuselage top sheet aluminum wings engine OS65 modified Glen Dye turned Rev-Up 9 x 13 prop uniflow pressure tank juiced 75% nitro fuel youre hot youre hot Bill man aged put up fastest official Jet time Friday well posting 19264 mph Super Burp design Model Avi ation plans #243 Hed reworked DynaJet engine along lines detailed Continued page 166 160 Model Aviation CHAMPION FF KITS Wakefield$44 95 Coupe$25 95* Wake-Up Mulvihill$2450 CHAMPION RUBBER 3/16 & 1/4 widths 042 thick $1195/lb BOx* CATALOG $100 CHAMPION MODEL PRODUCTS 880 Carmen Ct La Verne CA 91750 714 599-3348 Inclades US ddney xu UPSC4I resde,ts add 0% sates tax i UILD YOUR HELl TEST YOUR HELl AIR YOUR H ELI North 7th St ~I1 Lehighton Pa 18235 WRITE OR CALL FOR INFORMA TION ALREADY FLYING BIND NEW TRAINERS WITH RADIO AND ENGNE INSTALLED-OntyS300 FUTABA 4NLw/4S38 SERVOS S2OrTS R/G PARADISE 6089354206 660 KAUMANA Dr HILOHi 96720 PAW DIESELS Englands Finest 049 35 RIC STD S.d $100 list Eric Ciutton 913 Cedar Lane Tuliahoma Tenn 37388 CARBON MAT SAMPLE 2 OR 5 OZ/SO YD SEND $1 00 EACH TO AEROSPACE COMPOSITE PRODUCTS PO Box 16621 Ervine CA 92714
Edition: Model Aviation - 1987/09
Page Numbers: 81, 82, 83, 84, 158, 159, 160
The simple modifications described article will give Astro Model 102 charger consistent output make impervious input voltage fluc tuations allowing charge battery packs driving field EBob Kopski SEVERAL MONTHS AGO regu lar monthly RC Electrics column promised information modification Astro Model 102 DC/DC Super September 1987 81 mop xcup TUTU IOfl9Uf unarge ouro ruiuuuiuu rung ewulun uno larger Oattery clips modified charger looks very much did originally Using white 6-ft lamp cord makes convenientto hook upthe model its visible grass Switching larger clips provides better connection car batterysomething current-hungry chargers should have other mode arent made range switch relabeled Sharpie marking pen read 1-14 lower position 10-22 upperpositlon Above inside original Astro DC/DC charger pencil points originsi component thats re wiredthe controi pot White wire timer meter will replaced resistor pair FiGURE 1 Char OUTPUT CURRENT AW 7 Set Point 4A P 12V Inpi 12 Left graph shows what happens th original modified chargeroutput currents input voitage isvaried Tests included two differentbatterypacksan 8-cell 1 2Ah pack being charged onthe 1-14 cell range a20 cciii 2 Ah pack beingchargedonthe 10-22 cell range smaller pack set up charge 4 amps 12-volt input larger pack set up 3 amps same input voltage input varied up down such might happen starting running car engine easyto see improvement mod makes Right Graph depicts variation charge current tars fixed inputvoitagetothe chargerovera 1 5-minute charge cycle Two different 12 Ah packs testedan 8-cell 20-cell initial charge current time 0 set 4 amps Start Radio Shack terminal strip shown left Cut down shown right bendtheterminalsgO Solder resistor R7 shown carefully driii out mounting lug hois 3/16 Modifications should begin instal lation two 1-ohm 10 watt resistors Ri R2 resistors actually wired parallel form /rohm current-sam pling resistor Both resistors will get hot during operation very important thatthev cooxied aluminum canaL Charger modification easy stall will significantly improve performance already very fine prod uct applications Heres what its about Astro Super Charger may thought fully adjustable voltage converter effect charger can take 12-volt input auto battery change lower higher values done setting range switch adjustable control knob Thus charging pack containing few cells charger set relatively low output voltage pack has cells higher normal 12-volt car battery voltage needed charger adjusted provide Its like having variable auto battery help clear up some confusion about product subject charger 82 Model Aviation Tne terminsi strip assemmy neia piece aytne meisi-tramee inductors mounting screw Position strip clear everything Label wires pot original location can retained Remove wire pot lug nearest front photo solder right-hand lug terminal strip Remove other two wires pot soiderthem left lug terminal strip mix up FIGURE 3 Astro DC-DC Super Charger Modification Schematic Remove knob control pot remove pot front panel Solder three short wiressuch leftover resistor leadsto pot lugs run wIres through proper holes circuit board Keep board snug againstthe pot additional strength route wires through two holes circuit board bringing wire U shape back up through adjacent hole clr cult board Securely solder wire both points goes through board automaticie does sense battery charge condition shut itself off Rather has standard 15-minute timer switch control charge duration perfectly acceptable way doing things fact charging timed charge Therefore modification does change aspect chargers operation However charger also regu lated what modification about regulated sense selected battery charge current inherently stable rather varies both charge condition terminal volt age battery being charged auto battery voltage driving As consequence often necessary keep eye charge current readjust control knob during charging cycle Personally Im used charging stable charge current after seeing well Astro 102 otherwise performed began wonder about modifying September 1987 83 two connectons REPLACE existing wire NOTE All components shown pcholeboard subassembly except Ri R2 panel Ri terminal strip /Ri lOw SOLDER TOSOLDER TO UPPER TERMINAL1L--V\/\J~J ILEFT TERMINAL OF TIMER-SWITCHI P2 lOwJOF AqIETER GREY ORANGER3 22kR4 10k Original Control Pot CW ROTATION Increases Output P51kN TERMINAL STRIP TRANSISTOR QiDETAIL Cl luf35v R6lk YELLOWII II15k WIRE DIODE DlCZ 2Zuf iSvK YELLOW WIRE TO LEFTGREEN WIRE TO ORIGINAL LUG OF ADDED TERMINALCHARGER CIRCUIT BOARD STRIP RiSee photo 8 WIRES FROM ORIGINAL CIRCUIT BOARD--ORIGINALLY CONNECTED TO CONTROL POT simple circuIt addition needed stabilize charge current limited number re quired parts makes easy task some soldering experIence very important work carefully correctly because mistake could damage charger FIGURE 4 Astro DC-DC Super Charger Modification uit Board Pictorial SPECIAL NOTE LEADS VARY--SO BE SURE YOUR TRANSISTOR CEB LEADS GD TO CORRECT LOCATIONS COLLECTOR GREEN WIRE TO OIARGER CKT BOARD YELLOW WIRE TO TERMINAL STRIP EMITTER BASE P3 THIS PICTORIAL IS TOP VIEW R4 control pot 9 QI JtLr7JDlCi//R5 JORANGE WIRE TO TIMERSWITCH ALL DOTTED VERTICAL LINES INDICATE FOIL CONNECTORS ON CIRCUIT BOARD SPECIAL NOTE PC-HOLE BOARD MUST BE CUT TO SIZE WITH SHOLE CONDUCTOR PATTERN LOCATED BETWEEN THESE ARROWS BOARD IS 17 HOLES WIRE TO PANEL METER Almost circuit modification components assembled small piece circuit board wire leads identif led color used original assembly may change colors change wiring locationsbe sure what doingi Attach green wire directly original charger circuit board underneath large metal-framed inductor wire colors mentioned throughout procedure reference four distInct colors could usedbut dont mix up locational Install other components nns circume ~ardasshownintheassembiydrawing careful get capacitor diode polarities correct Make sure transistor leads inthe approprIate iocationssomett5n515t0r choices have leads different locations Connect 6-in lead-out wires shown Standard RC wire Ace RC okay include output current stabilization article result pursuing idea simple additional circuitry described herein makes selected charge current much stable Once set have readjust charge value over 15-minute timer period best part about charging can done auto engine running can arrive field ready fly See Model Avi ation March July 1985 Just re member attempt charging batteries driving car modi fication could disastrous since input voltage variation occurs car runmng causes similar tremendous vari ation charger output current course everything else life somethings just gotta wrong thing sounds goodright Yup four disadvantages associated modification First circuit modification reduces two maximum number cells could otherwise charged cause added circuitry uses some available charger output voltage makes unavailable battery being charged Second modified charger uses slight ly current auto battery runs somewhat hotter result charger output current flowing through added sampling resistor R1-R2 have found no ill effects because Third trickle charge now unadjust able Ordinarily small trickle charge current can set charger timer off As rule never trickle charge anyway besides coarse scale meter doesnt permit readable values such low currents begin withso doesnt bother fourth disadvantage drawback under particular set circum stances Ill call fourth difference modification output current charger cannot turned completely zero lowest output about 12 amps control knob adjusts upward woukl disadvantage wanted charge very small cells such 250 mAh smaller Now feel youd like have described advantages can somehow make through life disadvantages read See works easy modiir Astro DC/DC Super Charger added circuItry charger modi fication consists assembling small circuit board usjng Radio Shack parts installing new subassembly DC/DC Super Charger changes original charger minimal re versibleso should ever want change back can original charger parts used onethe control pot wires rewired have follow sketches photos exactly work carefully Continued page 158 84 Model Aviation FIGURE 5 Astro DC-DC Super Charger Modification Misc Pictorial Details GREEN WIRE SI LITE t1Ii LAD IBITTED ORIGINAL POT WIRING SOLID RE-cONNECTIONS REItJVE add RI-R2 R2 WI RE REAR VIEW Left Pay particularattentlon rerouting wires original potentiometer mistake will cause extensive damage original charger circuit Right Parailel resistors Ri R2 replace wire orIgInally connecting panel meter timer switch Use short lengths 1 8-gauge lamp cord extend resistor leads required Ri R2 must epoxy-giued aiuminum panel heat-sink cooling purposes ORIGINAL CIRCUIT BOARD wider inductor V 0 inside completed sin u uiirur mmmi resistor ana wire going ins pilOt light should removed since InC trickle-charge circuit no longer functions original Reinstalithe control potwlth its newcircultboard attached intotheoriginal panel location Position circuit board clears everything Tighten pot mounting nut Reinstall control knob making sure pot turned fully CCW pointer t 7 n,lnk Trim fin. wire fr irnh -"er appropriate destinations PRACTICAL SIZED GIANT Order Canopies Available Plans sent Post-Paid within USA Send 5Oe Full Catalog Balsa Nick Ziroli 29 EdMar Dr Smithiown NY 11787 USA MODELS NICK ZIROLI Jets too Plans RK-20 RK-740 Ducted Fans Phantom38 span$1000 Viggen32 span$1000 F-1538 span$1000 Plan canopy$1500 516-234-5038 enclosing some photos modifications K&B 15 definitely improve ground rpm engine resulting airspeed As can see photograph stock crank left crank right has enlarged extra meat has taken out shaft area addition venturi has enlarged some 015 second photograph shows enlarge ment venturi well giving view back crank can see enlarged hole extra meat removed up near timing area particular cranks close around 620 after top dead center ATDC Ron Youngs Performance Engines will rework cranks you can make modifica tion yourself Ron indicates enlarged crankshaft K&B/Cox 15 will flow approximately 30% air through engine minimum 500 rpm gain test stand Racing tank refueling procedures Several Gone forever nightmare heli-flier dreads stepping 3 foot tenna ripping off front prized chopper just ifs ready fly Base loaded short WHIPANTENNA f iveshidden performance Less 7 ong can mounted project front helicopter inside canopy ts virtually invtsible cZv~ 00R0A54 MODEL PRODUCTS 23961 CRAFTSMAN RD CALABASAS CA 91302 818 992-0195 218 VERNON ROAD GREENVILLE PA 16125 412 588-1321 competitors have written asking prevent damage fuel tank fill tube during hasty pit stop tube occasionally pushed down quick-fill too far rams hole bottom tank Ron Esman Texas Racing contingent found soldering small ring onto neck fuel filler ring prevents fill tube going too far tank Also size ring prevents fuel squirting back pit mans face deflects spray either side aircraft ring can easily fabricated large washer soldered place after measuring length tube enters tank Mouse Racing Al Lidberg Tempe AZ has sent some plans Annie Mouse Racer particular aircraft flies very well has very successful local competition flying area am including plan months column am sure would like further information can write Al Lidberg 614 W Fordham Tempe AZ 85283 St Louis alive well just talked Gary Frost St Louis area indicated both flying field club both excellent health Gary planning early October contest 87 people have written asked what happened St Louis will understand contest schedule once again reinstated major problem Buder Park flying site last summers contest schedule interruption park used horse shows instead model airplanes Gary assures has rectified 1987 fine Midwest site should again scene fine annual meet AMA records Racing received several requests mentioning Racing events being cluded AMA National Records As talk AMA district representatives both VP CL Contest Board please men tion Racing contingent would like have AMA records Racing events am sure voice heard something will done F2C Team Racer drawings have over dozen requests six sets plans Russian TRs. have sent copies everyone requested anyone else might have missed column still have several copies left will happy forward As always comments photographs appreciated John C Ballard 10102 Kimblewick Dr Louisville KY 40223 Charger/Kopski Continued page 84 dont feel comfortable confident sol dering get someone help works Space does permit detailed discussion technical details circuity operation Id like least pass along brief explanation basic idea involved As mentioned above although DC/DC Super Charger fully adjustable may provide stable charge current because set value current part dependent certain conditions external charger modification presented corrects adding internal reference charge current feedback circuit au tomatically adjusts charger operation output current should stray chosen value Referring schematic modified charger output current flows through ohm sampling resistor RL-R2 voltage appearing across resistance directly proportional charge current small circuit-card subassembly contains PNP transistor base-emitter junc tion watches voltage Adjustable divider R3-R4the new current control selects portion R1-R2 voltage application transistor Note R4 rewired original 10K control plus range switch still used adjust desired output current collector transistor con nected original electronics charger control pot origi nally wired effect transistor comes new controlling device original circuit happens because transistor collector will conduct current base emitter junction does So depending setting R4 sampled charge current causes about 06 volts often called VBE Threshold used voltage reference appear base-emitter junction tran sistor collector applies control signal original location adjustment control done way maintain steady output current 158 Model Aviation DC-3 1140 Span$4200 F4U CORSAIR2% Span$3000 ASMS ZERO2% pan$3000 CURTIS P402% Span$3000 AT-S TEXAN24 Span$3000 F8FBEARCAT2% Span$3000 FOKKERDR-127 Tripa$2700 Whip Antenna Gives Hidden Performance Thus some reason chosen value charge current should rise such auto engine started alternator causes auto battery voltage rise transistor control circuit instructs charger electronics lower its output maintain steady charge Similarly some reason charge current should drop such due rising voltage battery being charged lower sampled current sensed transistor re adjusts desired value hap pens quickly quietly automatically graphs show typical charger output current behavior both original modified versions As function other added components resistor R5 prevents exces sive damaging current flowing transistor base R6 Cl C2 Dl perform filtering functions com bined original new electronics work together properly Resistor R7 terminal strip makes up missing pot originally circuit Using modified Super Charger very much like using unmodified version suggest turn current control down minimum select range switch setting correspond number cells being charged Connect charger clips auto battery output cable model battery Turn timer switch fully clockwise set current control knob desired current meter reading Thats Thoughts suggestions Essentially needed information modifying charger given photos captions some additional offerings considering modification Several chargers have modified using information have worked billed effort has made assure satisfactory operationincluding extensive field testing accounts delayed article should clear task beginner also should easy straightforward reasonable skill relevant experience may notice charger current varies whenever operating transmitter brought within close proximity natural consequence radiated signal interfering charger electronicsso dont worry dont either natural consequence using charger assured constant-timed current flights same profile will become remarkably uniform duration particularly noticeable sport aerobatic models Sailplanes absence thermal activity has become routine experience con secutive aerobatic flights having nominal durations about five minutes clock within just few seconds other Finally no doubt have already thought realize other modification will void product .EEEEEEU SEe GLOW FUEL MANUFACTURED WITH THE PUREST FINEST QUALITY INGREDIENTS AVAILABLE * Superior Igniters Improve starting idle acceleration Youll notice power bargain fuels * Special Detergents Promote clean burning prevent residue buildup * Rust Inhibitors Protect engines corrosion After run oil needed engines * Film Strength Additives Increase lubricity provide extra lean run protection * Anti-Wear Additives Help keep engines running peak performance longer * Satisfaction Guaranteed SIG CHAMPION 2-STROKE FUEL FREIGHT FREE SHIPPING ON ORDERS OVER $1500 COLLECT PINTQUART GALLON55 GAL DRUM 0%Nitromethane$315$450$1050$19000 5%Nitromethane$365$525$1250$25800 10%Nitromethane$415$550$1450$32500 15%Nitromethane$430$625$1650$38500 25%Nitromethane$495$750$2095$52000 35%Nitromethane$575$875$2495$66000 SIG PREMIUM4-STROKE FUEL 10%Nitromethane$415$550$1395$29500 15%Nitromethane$425$625$1595$35900 THECHOICE OF CHAMPIONFLYERS over 20 years SIG has blending finest quality model engine fuel available using finest quality ingredients instance Methanol use 995% pure very best grade money can buy also use real 100% pure Nitromethane get full measure youve paid based honest percentage-of-volume method percentage weight SIG fuels con tain 50-50 blend Bakers purest AA Castor Oil new improved Klotz Techniplate Synthetic Racing Oil maximum engine lubrication protection Based experience sincerely believe finest quality fuel can made price dont take word try some judge 1111111 N iuii BROWN JR CAMPBELL COMET COVERITE COX EASY BUILT MODELS ENYA- FAt INE Fox GOLDBERG- GOLDEN AGE REPRO GENE DUBOIS GUILLOW- K&B K&S L R MRC OS MAX PACTRA PECK-POLYMER PERFECT R/N MODELS SEAGLEN SIG STERLING SULLIVAN SUPER TIGRE TAFFINDER TELCO- TOP FLITE- TREXLER WILLIAMS & OTHERS ESTES MODEL ROCKETS Send $100 Cash Check Stamps 44 page tahlold sire DISCOUNT Catalog 900 illostrations osrr 700 Kits choose MAILORDER PIIONEORDER IN STORE PENN VALLEY DOUBT CENTER 137 1 Kain 3t Lanidalmla 19441 September1987 159 TKieeha11 RIC 1db-Bar Glow Plugs Long orOnly $189 Also. Traditional line non-idle bar Glow Plugs Six Types 3 Heat Ranges High Performance Glow Element Blow Proof Seal Only $149 Swanson Associates PO Box 151 Since 7948 Wayne NJ 07470 warranty Just know Good luck charger modifi cation Im sure youll find stable reliable charge current affords well worth small effort cost needed achieve Happy Silent Flying Electrics Please forward comments ques tions SASE please author Bob Kopski 25 West End Dr Lansdale I When responding advertisers mention read about ModelAviation JET ENGINESSALE DYNAJETS $19900 Catalog $500 AL TOmE 4015 Ban Jacjsxto # 404 0 Houston Texas flOO4 p13 4404744 WANNA RACE NARTHFAT ARFA* BEGINNER RACESr Q-500 * FORM-i * FAI Instructions Club Programs informatiot Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVE FRANKLIN MASS 02038 Tel 617 528-4043 203 673 -2000 PA 19446 Parts List Radio Shack PartDescriptionPt No Ri1 ohm 10 watt resistor271 131 R21 ohm 10 watt resistor271 131 R322 K ohm resistor271 1325 R410 Kohmcontrolpotorig inal charger output control R51 K ohm resistor271 1321 R61 K ohm resistor271 1321 R715 K ohm resistor271 1337 Cl1OuF35VTantalum2721434 capacitor C2 22 uF 16 V Tantalum 2721437 capacitor 01 PNPtransistoranyoneof MP52907 M PS3638 2N2907 2N2907A 2N3906 Dl Silicon diode 1N914 1N4148 1 N4454 Miscellaneous PC Holeboard cut from 276 170 Terminal strip made from274 688 Wire Ace RC similar required 3/1 6in inside dia star washer Auto battery clips large 270 344 Six ft white 18-gauge lamp cord optional Solder required EpoxyDevcon 2-Ton white slow cure hardware store Time Three four hours Burt Rutan/Worth Continued page 91 discussion indicated desire part get 1987 Nats Lincoln meet old friends famous modelers After luncheon made firm Burt expected guest honor AMA banquet Wednesday Nats week AMA awards ceremony tended Burt Rutan friend Tonya Simone AMA President Don Lowe Na tional Aeronautic Association Executive Vice President Ev Langworthy AMA Executive Director John Worth Mrs Worth AMA Vice-Presidents Don Krafft District 1 Dave Brown 3 Howard Crispin 4 John Clemens 8 Dick Crowley 9 also AMA member Dave Edmonds HQ staffers Hurst Bowers Joyce Hager Geoff Styles Jeff Troy Vince Mankowski Lou Ward Doug Pratt Special guests Luther Hux wife Dawnthey provided model Voyager luncheon cen terpiece also photos article Postscript Voyager model RC flown time awards ceremony next morningfollow ing advice Burt concerning trim design factorsLuther Hux flew model successfully four times As fullscale design model flies well 276 2023a fitting follow-up evening before 276 2032when Luther said Dick Rutan Jeana Yeager During past years have flying Space Shuttle model AMA air shows Whenever landed everyone cheered watching real 2761122thing know cheers 2761122the model people flew full-scale Shuttle matter pride achieved Americans year fly Voyager model Im looking forward listening cheer CL Regionals/Hazel Continued page 94 As customary least some winning Speed flights posted Fri day Bill Nusz Lancaster CA shook up air bit fastest Class D time meet 19557 mph also turned out fastest official time event Bills ship original built Newton glass fuselage top sheet aluminum wings engine OS65 modified Glen Dye turned Rev-Up 9 x 13 prop uniflow pressure tank juiced 75% nitro fuel youre hot youre hot Bill man aged put up fastest official Jet time Friday well posting 19264 mph Super Burp design Model Avi ation plans #243 Hed reworked DynaJet engine along lines detailed Continued page 166 160 Model Aviation CHAMPION FF KITS Wakefield$44 95 Coupe$25 95* Wake-Up Mulvihill$2450 CHAMPION RUBBER 3/16 & 1/4 widths 042 thick $1195/lb BOx* CATALOG $100 CHAMPION MODEL PRODUCTS 880 Carmen Ct La Verne CA 91750 714 599-3348 Inclades US ddney xu UPSC4I resde,ts add 0% sates tax i UILD YOUR HELl TEST YOUR HELl AIR YOUR H ELI North 7th St ~I1 Lehighton Pa 18235 WRITE OR CALL FOR INFORMA TION ALREADY FLYING BIND NEW TRAINERS WITH RADIO AND ENGNE INSTALLED-OntyS300 FUTABA 4NLw/4S38 SERVOS S2OrTS R/G PARADISE 6089354206 660 KAUMANA Dr HILOHi 96720 PAW DIESELS Englands Finest 049 35 RIC STD S.d $100 list Eric Ciutton 913 Cedar Lane Tuliahoma Tenn 37388 CARBON MAT SAMPLE 2 OR 5 OZ/SO YD SEND $1 00 EACH TO AEROSPACE COMPOSITE PRODUCTS PO Box 16621 Ervine CA 92714
Edition: Model Aviation - 1987/09
Page Numbers: 81, 82, 83, 84, 158, 159, 160
The simple modifications described article will give Astro Model 102 charger consistent output make impervious input voltage fluc tuations allowing charge battery packs driving field EBob Kopski SEVERAL MONTHS AGO regu lar monthly RC Electrics column promised information modification Astro Model 102 DC/DC Super September 1987 81 mop xcup TUTU IOfl9Uf unarge ouro ruiuuuiuu rung ewulun uno larger Oattery clips modified charger looks very much did originally Using white 6-ft lamp cord makes convenientto hook upthe model its visible grass Switching larger clips provides better connection car batterysomething current-hungry chargers should have other mode arent made range switch relabeled Sharpie marking pen read 1-14 lower position 10-22 upperpositlon Above inside original Astro DC/DC charger pencil points originsi component thats re wiredthe controi pot White wire timer meter will replaced resistor pair FiGURE 1 Char OUTPUT CURRENT AW 7 Set Point 4A P 12V Inpi 12 Left graph shows what happens th original modified chargeroutput currents input voitage isvaried Tests included two differentbatterypacksan 8-cell 1 2Ah pack being charged onthe 1-14 cell range a20 cciii 2 Ah pack beingchargedonthe 10-22 cell range smaller pack set up charge 4 amps 12-volt input larger pack set up 3 amps same input voltage input varied up down such might happen starting running car engine easyto see improvement mod makes Right Graph depicts variation charge current tars fixed inputvoitagetothe chargerovera 1 5-minute charge cycle Two different 12 Ah packs testedan 8-cell 20-cell initial charge current time 0 set 4 amps Start Radio Shack terminal strip shown left Cut down shown right bendtheterminalsgO Solder resistor R7 shown carefully driii out mounting lug hois 3/16 Modifications should begin instal lation two 1-ohm 10 watt resistors Ri R2 resistors actually wired parallel form /rohm current-sam pling resistor Both resistors will get hot during operation very important thatthev cooxied aluminum canaL Charger modification easy stall will significantly improve performance already very fine prod uct applications Heres what its about Astro Super Charger may thought fully adjustable voltage converter effect charger can take 12-volt input auto battery change lower higher values done setting range switch adjustable control knob Thus charging pack containing few cells charger set relatively low output voltage pack has cells higher normal 12-volt car battery voltage needed charger adjusted provide Its like having variable auto battery help clear up some confusion about product subject charger 82 Model Aviation Tne terminsi strip assemmy neia piece aytne meisi-tramee inductors mounting screw Position strip clear everything Label wires pot original location can retained Remove wire pot lug nearest front photo solder right-hand lug terminal strip Remove other two wires pot soiderthem left lug terminal strip mix up FIGURE 3 Astro DC-DC Super Charger Modification Schematic Remove knob control pot remove pot front panel Solder three short wiressuch leftover resistor leadsto pot lugs run wIres through proper holes circuit board Keep board snug againstthe pot additional strength route wires through two holes circuit board bringing wire U shape back up through adjacent hole clr cult board Securely solder wire both points goes through board automaticie does sense battery charge condition shut itself off Rather has standard 15-minute timer switch control charge duration perfectly acceptable way doing things fact charging timed charge Therefore modification does change aspect chargers operation However charger also regu lated what modification about regulated sense selected battery charge current inherently stable rather varies both charge condition terminal volt age battery being charged auto battery voltage driving As consequence often necessary keep eye charge current readjust control knob during charging cycle Personally Im used charging stable charge current after seeing well Astro 102 otherwise performed began wonder about modifying September 1987 83 two connectons REPLACE existing wire NOTE All components shown pcholeboard subassembly except Ri R2 panel Ri terminal strip /Ri lOw SOLDER TOSOLDER TO UPPER TERMINAL1L--V\/\J~J ILEFT TERMINAL OF TIMER-SWITCHI P2 lOwJOF AqIETER GREY ORANGER3 22kR4 10k Original Control Pot CW ROTATION Increases Output P51kN TERMINAL STRIP TRANSISTOR QiDETAIL Cl luf35v R6lk YELLOWII II15k WIRE DIODE DlCZ 2Zuf iSvK YELLOW WIRE TO LEFTGREEN WIRE TO ORIGINAL LUG OF ADDED TERMINALCHARGER CIRCUIT BOARD STRIP RiSee photo 8 WIRES FROM ORIGINAL CIRCUIT BOARD--ORIGINALLY CONNECTED TO CONTROL POT simple circuIt addition needed stabilize charge current limited number re quired parts makes easy task some soldering experIence very important work carefully correctly because mistake could damage charger FIGURE 4 Astro DC-DC Super Charger Modification uit Board Pictorial SPECIAL NOTE LEADS VARY--SO BE SURE YOUR TRANSISTOR CEB LEADS GD TO CORRECT LOCATIONS COLLECTOR GREEN WIRE TO OIARGER CKT BOARD YELLOW WIRE TO TERMINAL STRIP EMITTER BASE P3 THIS PICTORIAL IS TOP VIEW R4 control pot 9 QI JtLr7JDlCi//R5 JORANGE WIRE TO TIMERSWITCH ALL DOTTED VERTICAL LINES INDICATE FOIL CONNECTORS ON CIRCUIT BOARD SPECIAL NOTE PC-HOLE BOARD MUST BE CUT TO SIZE WITH SHOLE CONDUCTOR PATTERN LOCATED BETWEEN THESE ARROWS BOARD IS 17 HOLES WIRE TO PANEL METER Almost circuit modification components assembled small piece circuit board wire leads identif led color used original assembly may change colors change wiring locationsbe sure what doingi Attach green wire directly original charger circuit board underneath large metal-framed inductor wire colors mentioned throughout procedure reference four distInct colors could usedbut dont mix up locational Install other components nns circume ~ardasshownintheassembiydrawing careful get capacitor diode polarities correct Make sure transistor leads inthe approprIate iocationssomett5n515t0r choices have leads different locations Connect 6-in lead-out wires shown Standard RC wire Ace RC okay include output current stabilization article result pursuing idea simple additional circuitry described herein makes selected charge current much stable Once set have readjust charge value over 15-minute timer period best part about charging can done auto engine running can arrive field ready fly See Model Avi ation March July 1985 Just re member attempt charging batteries driving car modi fication could disastrous since input voltage variation occurs car runmng causes similar tremendous vari ation charger output current course everything else life somethings just gotta wrong thing sounds goodright Yup four disadvantages associated modification First circuit modification reduces two maximum number cells could otherwise charged cause added circuitry uses some available charger output voltage makes unavailable battery being charged Second modified charger uses slight ly current auto battery runs somewhat hotter result charger output current flowing through added sampling resistor R1-R2 have found no ill effects because Third trickle charge now unadjust able Ordinarily small trickle charge current can set charger timer off As rule never trickle charge anyway besides coarse scale meter doesnt permit readable values such low currents begin withso doesnt bother fourth disadvantage drawback under particular set circum stances Ill call fourth difference modification output current charger cannot turned completely zero lowest output about 12 amps control knob adjusts upward woukl disadvantage wanted charge very small cells such 250 mAh smaller Now feel youd like have described advantages can somehow make through life disadvantages read See works easy modiir Astro DC/DC Super Charger added circuItry charger modi fication consists assembling small circuit board usjng Radio Shack parts installing new subassembly DC/DC Super Charger changes original charger minimal re versibleso should ever want change back can original charger parts used onethe control pot wires rewired have follow sketches photos exactly work carefully Continued page 158 84 Model Aviation FIGURE 5 Astro DC-DC Super Charger Modification Misc Pictorial Details GREEN WIRE SI LITE t1Ii LAD IBITTED ORIGINAL POT WIRING SOLID RE-cONNECTIONS REItJVE add RI-R2 R2 WI RE REAR VIEW Left Pay particularattentlon rerouting wires original potentiometer mistake will cause extensive damage original charger circuit Right Parailel resistors Ri R2 replace wire orIgInally connecting panel meter timer switch Use short lengths 1 8-gauge lamp cord extend resistor leads required Ri R2 must epoxy-giued aiuminum panel heat-sink cooling purposes ORIGINAL CIRCUIT BOARD wider inductor V 0 inside completed sin u uiirur mmmi resistor ana wire going ins pilOt light should removed since InC trickle-charge circuit no longer functions original Reinstalithe control potwlth its newcircultboard attached intotheoriginal panel location Position circuit board clears everything Tighten pot mounting nut Reinstall control knob making sure pot turned fully CCW pointer t 7 n,lnk Trim fin. wire fr irnh -"er appropriate destinations PRACTICAL SIZED GIANT Order Canopies Available Plans sent Post-Paid within USA Send 5Oe Full Catalog Balsa Nick Ziroli 29 EdMar Dr Smithiown NY 11787 USA MODELS NICK ZIROLI Jets too Plans RK-20 RK-740 Ducted Fans Phantom38 span$1000 Viggen32 span$1000 F-1538 span$1000 Plan canopy$1500 516-234-5038 enclosing some photos modifications K&B 15 definitely improve ground rpm engine resulting airspeed As can see photograph stock crank left crank right has enlarged extra meat has taken out shaft area addition venturi has enlarged some 015 second photograph shows enlarge ment venturi well giving view back crank can see enlarged hole extra meat removed up near timing area particular cranks close around 620 after top dead center ATDC Ron Youngs Performance Engines will rework cranks you can make modifica tion yourself Ron indicates enlarged crankshaft K&B/Cox 15 will flow approximately 30% air through engine minimum 500 rpm gain test stand Racing tank refueling procedures Several Gone forever nightmare heli-flier dreads stepping 3 foot tenna ripping off front prized chopper just ifs ready fly Base loaded short WHIPANTENNA f iveshidden performance Less 7 ong can mounted project front helicopter inside canopy ts virtually invtsible cZv~ 00R0A54 MODEL PRODUCTS 23961 CRAFTSMAN RD CALABASAS CA 91302 818 992-0195 218 VERNON ROAD GREENVILLE PA 16125 412 588-1321 competitors have written asking prevent damage fuel tank fill tube during hasty pit stop tube occasionally pushed down quick-fill too far rams hole bottom tank Ron Esman Texas Racing contingent found soldering small ring onto neck fuel filler ring prevents fill tube going too far tank Also size ring prevents fuel squirting back pit mans face deflects spray either side aircraft ring can easily fabricated large washer soldered place after measuring length tube enters tank Mouse Racing Al Lidberg Tempe AZ has sent some plans Annie Mouse Racer particular aircraft flies very well has very successful local competition flying area am including plan months column am sure would like further information can write Al Lidberg 614 W Fordham Tempe AZ 85283 St Louis alive well just talked Gary Frost St Louis area indicated both flying field club both excellent health Gary planning early October contest 87 people have written asked what happened St Louis will understand contest schedule once again reinstated major problem Buder Park flying site last summers contest schedule interruption park used horse shows instead model airplanes Gary assures has rectified 1987 fine Midwest site should again scene fine annual meet AMA records Racing received several requests mentioning Racing events being cluded AMA National Records As talk AMA district representatives both VP CL Contest Board please men tion Racing contingent would like have AMA records Racing events am sure voice heard something will done F2C Team Racer drawings have over dozen requests six sets plans Russian TRs. have sent copies everyone requested anyone else might have missed column still have several copies left will happy forward As always comments photographs appreciated John C Ballard 10102 Kimblewick Dr Louisville KY 40223 Charger/Kopski Continued page 84 dont feel comfortable confident sol dering get someone help works Space does permit detailed discussion technical details circuity operation Id like least pass along brief explanation basic idea involved As mentioned above although DC/DC Super Charger fully adjustable may provide stable charge current because set value current part dependent certain conditions external charger modification presented corrects adding internal reference charge current feedback circuit au tomatically adjusts charger operation output current should stray chosen value Referring schematic modified charger output current flows through ohm sampling resistor RL-R2 voltage appearing across resistance directly proportional charge current small circuit-card subassembly contains PNP transistor base-emitter junc tion watches voltage Adjustable divider R3-R4the new current control selects portion R1-R2 voltage application transistor Note R4 rewired original 10K control plus range switch still used adjust desired output current collector transistor con nected original electronics charger control pot origi nally wired effect transistor comes new controlling device original circuit happens because transistor collector will conduct current base emitter junction does So depending setting R4 sampled charge current causes about 06 volts often called VBE Threshold used voltage reference appear base-emitter junction tran sistor collector applies control signal original location adjustment control done way maintain steady output current 158 Model Aviation DC-3 1140 Span$4200 F4U CORSAIR2% Span$3000 ASMS ZERO2% pan$3000 CURTIS P402% Span$3000 AT-S TEXAN24 Span$3000 F8FBEARCAT2% Span$3000 FOKKERDR-127 Tripa$2700 Whip Antenna Gives Hidden Performance Thus some reason chosen value charge current should rise such auto engine started alternator causes auto battery voltage rise transistor control circuit instructs charger electronics lower its output maintain steady charge Similarly some reason charge current should drop such due rising voltage battery being charged lower sampled current sensed transistor re adjusts desired value hap pens quickly quietly automatically graphs show typical charger output current behavior both original modified versions As function other added components resistor R5 prevents exces sive damaging current flowing transistor base R6 Cl C2 Dl perform filtering functions com bined original new electronics work together properly Resistor R7 terminal strip makes up missing pot originally circuit Using modified Super Charger very much like using unmodified version suggest turn current control down minimum select range switch setting correspond number cells being charged Connect charger clips auto battery output cable model battery Turn timer switch fully clockwise set current control knob desired current meter reading Thats Thoughts suggestions Essentially needed information modifying charger given photos captions some additional offerings considering modification Several chargers have modified using information have worked billed effort has made assure satisfactory operationincluding extensive field testing accounts delayed article should clear task beginner also should easy straightforward reasonable skill relevant experience may notice charger current varies whenever operating transmitter brought within close proximity natural consequence radiated signal interfering charger electronicsso dont worry dont either natural consequence using charger assured constant-timed current flights same profile will become remarkably uniform duration particularly noticeable sport aerobatic models Sailplanes absence thermal activity has become routine experience con secutive aerobatic flights having nominal durations about five minutes clock within just few seconds other Finally no doubt have already thought realize other modification will void product .EEEEEEU SEe GLOW FUEL MANUFACTURED WITH THE PUREST FINEST QUALITY INGREDIENTS AVAILABLE * Superior Igniters Improve starting idle acceleration Youll notice power bargain fuels * Special Detergents Promote clean burning prevent residue buildup * Rust Inhibitors Protect engines corrosion After run oil needed engines * Film Strength Additives Increase lubricity provide extra lean run protection * Anti-Wear Additives Help keep engines running peak performance longer * Satisfaction Guaranteed SIG CHAMPION 2-STROKE FUEL FREIGHT FREE SHIPPING ON ORDERS OVER $1500 COLLECT PINTQUART GALLON55 GAL DRUM 0%Nitromethane$315$450$1050$19000 5%Nitromethane$365$525$1250$25800 10%Nitromethane$415$550$1450$32500 15%Nitromethane$430$625$1650$38500 25%Nitromethane$495$750$2095$52000 35%Nitromethane$575$875$2495$66000 SIG PREMIUM4-STROKE FUEL 10%Nitromethane$415$550$1395$29500 15%Nitromethane$425$625$1595$35900 THECHOICE OF CHAMPIONFLYERS over 20 years SIG has blending finest quality model engine fuel available using finest quality ingredients instance Methanol use 995% pure very best grade money can buy also use real 100% pure Nitromethane get full measure youve paid based honest percentage-of-volume method percentage weight SIG fuels con tain 50-50 blend Bakers purest AA Castor Oil new improved Klotz Techniplate Synthetic Racing Oil maximum engine lubrication protection Based experience sincerely believe finest quality fuel can made price dont take word try some judge 1111111 N iuii BROWN JR CAMPBELL COMET COVERITE COX EASY BUILT MODELS ENYA- FAt INE Fox GOLDBERG- GOLDEN AGE REPRO GENE DUBOIS GUILLOW- K&B K&S L R MRC OS MAX PACTRA PECK-POLYMER PERFECT R/N MODELS SEAGLEN SIG STERLING SULLIVAN SUPER TIGRE TAFFINDER TELCO- TOP FLITE- TREXLER WILLIAMS & OTHERS ESTES MODEL ROCKETS Send $100 Cash Check Stamps 44 page tahlold sire DISCOUNT Catalog 900 illostrations osrr 700 Kits choose MAILORDER PIIONEORDER IN STORE PENN VALLEY DOUBT CENTER 137 1 Kain 3t Lanidalmla 19441 September1987 159 TKieeha11 RIC 1db-Bar Glow Plugs Long orOnly $189 Also. Traditional line non-idle bar Glow Plugs Six Types 3 Heat Ranges High Performance Glow Element Blow Proof Seal Only $149 Swanson Associates PO Box 151 Since 7948 Wayne NJ 07470 warranty Just know Good luck charger modifi cation Im sure youll find stable reliable charge current affords well worth small effort cost needed achieve Happy Silent Flying Electrics Please forward comments ques tions SASE please author Bob Kopski 25 West End Dr Lansdale I When responding advertisers mention read about ModelAviation JET ENGINESSALE DYNAJETS $19900 Catalog $500 AL TOmE 4015 Ban Jacjsxto # 404 0 Houston Texas flOO4 p13 4404744 WANNA RACE NARTHFAT ARFA* BEGINNER RACESr Q-500 * FORM-i * FAI Instructions Club Programs informatiot Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVE FRANKLIN MASS 02038 Tel 617 528-4043 203 673 -2000 PA 19446 Parts List Radio Shack PartDescriptionPt No Ri1 ohm 10 watt resistor271 131 R21 ohm 10 watt resistor271 131 R322 K ohm resistor271 1325 R410 Kohmcontrolpotorig inal charger output control R51 K ohm resistor271 1321 R61 K ohm resistor271 1321 R715 K ohm resistor271 1337 Cl1OuF35VTantalum2721434 capacitor C2 22 uF 16 V Tantalum 2721437 capacitor 01 PNPtransistoranyoneof MP52907 M PS3638 2N2907 2N2907A 2N3906 Dl Silicon diode 1N914 1N4148 1 N4454 Miscellaneous PC Holeboard cut from 276 170 Terminal strip made from274 688 Wire Ace RC similar required 3/1 6in inside dia star washer Auto battery clips large 270 344 Six ft white 18-gauge lamp cord optional Solder required EpoxyDevcon 2-Ton white slow cure hardware store Time Three four hours Burt Rutan/Worth Continued page 91 discussion indicated desire part get 1987 Nats Lincoln meet old friends famous modelers After luncheon made firm Burt expected guest honor AMA banquet Wednesday Nats week AMA awards ceremony tended Burt Rutan friend Tonya Simone AMA President Don Lowe Na tional Aeronautic Association Executive Vice President Ev Langworthy AMA Executive Director John Worth Mrs Worth AMA Vice-Presidents Don Krafft District 1 Dave Brown 3 Howard Crispin 4 John Clemens 8 Dick Crowley 9 also AMA member Dave Edmonds HQ staffers Hurst Bowers Joyce Hager Geoff Styles Jeff Troy Vince Mankowski Lou Ward Doug Pratt Special guests Luther Hux wife Dawnthey provided model Voyager luncheon cen terpiece also photos article Postscript Voyager model RC flown time awards ceremony next morningfollow ing advice Burt concerning trim design factorsLuther Hux flew model successfully four times As fullscale design model flies well 276 2023a fitting follow-up evening before 276 2032when Luther said Dick Rutan Jeana Yeager During past years have flying Space Shuttle model AMA air shows Whenever landed everyone cheered watching real 2761122thing know cheers 2761122the model people flew full-scale Shuttle matter pride achieved Americans year fly Voyager model Im looking forward listening cheer CL Regionals/Hazel Continued page 94 As customary least some winning Speed flights posted Fri day Bill Nusz Lancaster CA shook up air bit fastest Class D time meet 19557 mph also turned out fastest official time event Bills ship original built Newton glass fuselage top sheet aluminum wings engine OS65 modified Glen Dye turned Rev-Up 9 x 13 prop uniflow pressure tank juiced 75% nitro fuel youre hot youre hot Bill man aged put up fastest official Jet time Friday well posting 19264 mph Super Burp design Model Avi ation plans #243 Hed reworked DynaJet engine along lines detailed Continued page 166 160 Model Aviation CHAMPION FF KITS Wakefield$44 95 Coupe$25 95* Wake-Up Mulvihill$2450 CHAMPION RUBBER 3/16 & 1/4 widths 042 thick $1195/lb BOx* CATALOG $100 CHAMPION MODEL PRODUCTS 880 Carmen Ct La Verne CA 91750 714 599-3348 Inclades US ddney xu UPSC4I resde,ts add 0% sates tax i UILD YOUR HELl TEST YOUR HELl AIR YOUR H ELI North 7th St ~I1 Lehighton Pa 18235 WRITE OR CALL FOR INFORMA TION ALREADY FLYING BIND NEW TRAINERS WITH RADIO AND ENGNE INSTALLED-OntyS300 FUTABA 4NLw/4S38 SERVOS S2OrTS R/G PARADISE 6089354206 660 KAUMANA Dr HILOHi 96720 PAW DIESELS Englands Finest 049 35 RIC STD S.d $100 list Eric Ciutton 913 Cedar Lane Tuliahoma Tenn 37388 CARBON MAT SAMPLE 2 OR 5 OZ/SO YD SEND $1 00 EACH TO AEROSPACE COMPOSITE PRODUCTS PO Box 16621 Ervine CA 92714
Edition: Model Aviation - 1987/09
Page Numbers: 81, 82, 83, 84, 158, 159, 160
The simple modifications described article will give Astro Model 102 charger consistent output make impervious input voltage fluc tuations allowing charge battery packs driving field EBob Kopski SEVERAL MONTHS AGO regu lar monthly RC Electrics column promised information modification Astro Model 102 DC/DC Super September 1987 81 mop xcup TUTU IOfl9Uf unarge ouro ruiuuuiuu rung ewulun uno larger Oattery clips modified charger looks very much did originally Using white 6-ft lamp cord makes convenientto hook upthe model its visible grass Switching larger clips provides better connection car batterysomething current-hungry chargers should have other mode arent made range switch relabeled Sharpie marking pen read 1-14 lower position 10-22 upperpositlon Above inside original Astro DC/DC charger pencil points originsi component thats re wiredthe controi pot White wire timer meter will replaced resistor pair FiGURE 1 Char OUTPUT CURRENT AW 7 Set Point 4A P 12V Inpi 12 Left graph shows what happens th original modified chargeroutput currents input voitage isvaried Tests included two differentbatterypacksan 8-cell 1 2Ah pack being charged onthe 1-14 cell range a20 cciii 2 Ah pack beingchargedonthe 10-22 cell range smaller pack set up charge 4 amps 12-volt input larger pack set up 3 amps same input voltage input varied up down such might happen starting running car engine easyto see improvement mod makes Right Graph depicts variation charge current tars fixed inputvoitagetothe chargerovera 1 5-minute charge cycle Two different 12 Ah packs testedan 8-cell 20-cell initial charge current time 0 set 4 amps Start Radio Shack terminal strip shown left Cut down shown right bendtheterminalsgO Solder resistor R7 shown carefully driii out mounting lug hois 3/16 Modifications should begin instal lation two 1-ohm 10 watt resistors Ri R2 resistors actually wired parallel form /rohm current-sam pling resistor Both resistors will get hot during operation very important thatthev cooxied aluminum canaL Charger modification easy stall will significantly improve performance already very fine prod uct applications Heres what its about Astro Super Charger may thought fully adjustable voltage converter effect charger can take 12-volt input auto battery change lower higher values done setting range switch adjustable control knob Thus charging pack containing few cells charger set relatively low output voltage pack has cells higher normal 12-volt car battery voltage needed charger adjusted provide Its like having variable auto battery help clear up some confusion about product subject charger 82 Model Aviation Tne terminsi strip assemmy neia piece aytne meisi-tramee inductors mounting screw Position strip clear everything Label wires pot original location can retained Remove wire pot lug nearest front photo solder right-hand lug terminal strip Remove other two wires pot soiderthem left lug terminal strip mix up FIGURE 3 Astro DC-DC Super Charger Modification Schematic Remove knob control pot remove pot front panel Solder three short wiressuch leftover resistor leadsto pot lugs run wIres through proper holes circuit board Keep board snug againstthe pot additional strength route wires through two holes circuit board bringing wire U shape back up through adjacent hole clr cult board Securely solder wire both points goes through board automaticie does sense battery charge condition shut itself off Rather has standard 15-minute timer switch control charge duration perfectly acceptable way doing things fact charging timed charge Therefore modification does change aspect chargers operation However charger also regu lated what modification about regulated sense selected battery charge current inherently stable rather varies both charge condition terminal volt age battery being charged auto battery voltage driving As consequence often necessary keep eye charge current readjust control knob during charging cycle Personally Im used charging stable charge current after seeing well Astro 102 otherwise performed began wonder about modifying September 1987 83 two connectons REPLACE existing wire NOTE All components shown pcholeboard subassembly except Ri R2 panel Ri terminal strip /Ri lOw SOLDER TOSOLDER TO UPPER TERMINAL1L--V\/\J~J ILEFT TERMINAL OF TIMER-SWITCHI P2 lOwJOF AqIETER GREY ORANGER3 22kR4 10k Original Control Pot CW ROTATION Increases Output P51kN TERMINAL STRIP TRANSISTOR QiDETAIL Cl luf35v R6lk YELLOWII II15k WIRE DIODE DlCZ 2Zuf iSvK YELLOW WIRE TO LEFTGREEN WIRE TO ORIGINAL LUG OF ADDED TERMINALCHARGER CIRCUIT BOARD STRIP RiSee photo 8 WIRES FROM ORIGINAL CIRCUIT BOARD--ORIGINALLY CONNECTED TO CONTROL POT simple circuIt addition needed stabilize charge current limited number re quired parts makes easy task some soldering experIence very important work carefully correctly because mistake could damage charger FIGURE 4 Astro DC-DC Super Charger Modification uit Board Pictorial SPECIAL NOTE LEADS VARY--SO BE SURE YOUR TRANSISTOR CEB LEADS GD TO CORRECT LOCATIONS COLLECTOR GREEN WIRE TO OIARGER CKT BOARD YELLOW WIRE TO TERMINAL STRIP EMITTER BASE P3 THIS PICTORIAL IS TOP VIEW R4 control pot 9 QI JtLr7JDlCi//R5 JORANGE WIRE TO TIMERSWITCH ALL DOTTED VERTICAL LINES INDICATE FOIL CONNECTORS ON CIRCUIT BOARD SPECIAL NOTE PC-HOLE BOARD MUST BE CUT TO SIZE WITH SHOLE CONDUCTOR PATTERN LOCATED BETWEEN THESE ARROWS BOARD IS 17 HOLES WIRE TO PANEL METER Almost circuit modification components assembled small piece circuit board wire leads identif led color used original assembly may change colors change wiring locationsbe sure what doingi Attach green wire directly original charger circuit board underneath large metal-framed inductor wire colors mentioned throughout procedure reference four distInct colors could usedbut dont mix up locational Install other components nns circume ~ardasshownintheassembiydrawing careful get capacitor diode polarities correct Make sure transistor leads inthe approprIate iocationssomett5n515t0r choices have leads different locations Connect 6-in lead-out wires shown Standard RC wire Ace RC okay include output current stabilization article result pursuing idea simple additional circuitry described herein makes selected charge current much stable Once set have readjust charge value over 15-minute timer period best part about charging can done auto engine running can arrive field ready fly See Model Avi ation March July 1985 Just re member attempt charging batteries driving car modi fication could disastrous since input voltage variation occurs car runmng causes similar tremendous vari ation charger output current course everything else life somethings just gotta wrong thing sounds goodright Yup four disadvantages associated modification First circuit modification reduces two maximum number cells could otherwise charged cause added circuitry uses some available charger output voltage makes unavailable battery being charged Second modified charger uses slight ly current auto battery runs somewhat hotter result charger output current flowing through added sampling resistor R1-R2 have found no ill effects because Third trickle charge now unadjust able Ordinarily small trickle charge current can set charger timer off As rule never trickle charge anyway besides coarse scale meter doesnt permit readable values such low currents begin withso doesnt bother fourth disadvantage drawback under particular set circum stances Ill call fourth difference modification output current charger cannot turned completely zero lowest output about 12 amps control knob adjusts upward woukl disadvantage wanted charge very small cells such 250 mAh smaller Now feel youd like have described advantages can somehow make through life disadvantages read See works easy modiir Astro DC/DC Super Charger added circuItry charger modi fication consists assembling small circuit board usjng Radio Shack parts installing new subassembly DC/DC Super Charger changes original charger minimal re versibleso should ever want change back can original charger parts used onethe control pot wires rewired have follow sketches photos exactly work carefully Continued page 158 84 Model Aviation FIGURE 5 Astro DC-DC Super Charger Modification Misc Pictorial Details GREEN WIRE SI LITE t1Ii LAD IBITTED ORIGINAL POT WIRING SOLID RE-cONNECTIONS REItJVE add RI-R2 R2 WI RE REAR VIEW Left Pay particularattentlon rerouting wires original potentiometer mistake will cause extensive damage original charger circuit Right Parailel resistors Ri R2 replace wire orIgInally connecting panel meter timer switch Use short lengths 1 8-gauge lamp cord extend resistor leads required Ri R2 must epoxy-giued aiuminum panel heat-sink cooling purposes ORIGINAL CIRCUIT BOARD wider inductor V 0 inside completed sin u uiirur mmmi resistor ana wire going ins pilOt light should removed since InC trickle-charge circuit no longer functions original Reinstalithe control potwlth its newcircultboard attached intotheoriginal panel location Position circuit board clears everything Tighten pot mounting nut Reinstall control knob making sure pot turned fully CCW pointer t 7 n,lnk Trim fin. wire fr irnh -"er appropriate destinations PRACTICAL SIZED GIANT Order Canopies Available Plans sent Post-Paid within USA Send 5Oe Full Catalog Balsa Nick Ziroli 29 EdMar Dr Smithiown NY 11787 USA MODELS NICK ZIROLI Jets too Plans RK-20 RK-740 Ducted Fans Phantom38 span$1000 Viggen32 span$1000 F-1538 span$1000 Plan canopy$1500 516-234-5038 enclosing some photos modifications K&B 15 definitely improve ground rpm engine resulting airspeed As can see photograph stock crank left crank right has enlarged extra meat has taken out shaft area addition venturi has enlarged some 015 second photograph shows enlarge ment venturi well giving view back crank can see enlarged hole extra meat removed up near timing area particular cranks close around 620 after top dead center ATDC Ron Youngs Performance Engines will rework cranks you can make modifica tion yourself Ron indicates enlarged crankshaft K&B/Cox 15 will flow approximately 30% air through engine minimum 500 rpm gain test stand Racing tank refueling procedures Several Gone forever nightmare heli-flier dreads stepping 3 foot tenna ripping off front prized chopper just ifs ready fly Base loaded short WHIPANTENNA f iveshidden performance Less 7 ong can mounted project front helicopter inside canopy ts virtually invtsible cZv~ 00R0A54 MODEL PRODUCTS 23961 CRAFTSMAN RD CALABASAS CA 91302 818 992-0195 218 VERNON ROAD GREENVILLE PA 16125 412 588-1321 competitors have written asking prevent damage fuel tank fill tube during hasty pit stop tube occasionally pushed down quick-fill too far rams hole bottom tank Ron Esman Texas Racing contingent found soldering small ring onto neck fuel filler ring prevents fill tube going too far tank Also size ring prevents fuel squirting back pit mans face deflects spray either side aircraft ring can easily fabricated large washer soldered place after measuring length tube enters tank Mouse Racing Al Lidberg Tempe AZ has sent some plans Annie Mouse Racer particular aircraft flies very well has very successful local competition flying area am including plan months column am sure would like further information can write Al Lidberg 614 W Fordham Tempe AZ 85283 St Louis alive well just talked Gary Frost St Louis area indicated both flying field club both excellent health Gary planning early October contest 87 people have written asked what happened St Louis will understand contest schedule once again reinstated major problem Buder Park flying site last summers contest schedule interruption park used horse shows instead model airplanes Gary assures has rectified 1987 fine Midwest site should again scene fine annual meet AMA records Racing received several requests mentioning Racing events being cluded AMA National Records As talk AMA district representatives both VP CL Contest Board please men tion Racing contingent would like have AMA records Racing events am sure voice heard something will done F2C Team Racer drawings have over dozen requests six sets plans Russian TRs. have sent copies everyone requested anyone else might have missed column still have several copies left will happy forward As always comments photographs appreciated John C Ballard 10102 Kimblewick Dr Louisville KY 40223 Charger/Kopski Continued page 84 dont feel comfortable confident sol dering get someone help works Space does permit detailed discussion technical details circuity operation Id like least pass along brief explanation basic idea involved As mentioned above although DC/DC Super Charger fully adjustable may provide stable charge current because set value current part dependent certain conditions external charger modification presented corrects adding internal reference charge current feedback circuit au tomatically adjusts charger operation output current should stray chosen value Referring schematic modified charger output current flows through ohm sampling resistor RL-R2 voltage appearing across resistance directly proportional charge current small circuit-card subassembly contains PNP transistor base-emitter junc tion watches voltage Adjustable divider R3-R4the new current control selects portion R1-R2 voltage application transistor Note R4 rewired original 10K control plus range switch still used adjust desired output current collector transistor con nected original electronics charger control pot origi nally wired effect transistor comes new controlling device original circuit happens because transistor collector will conduct current base emitter junction does So depending setting R4 sampled charge current causes about 06 volts often called VBE Threshold used voltage reference appear base-emitter junction tran sistor collector applies control signal original location adjustment control done way maintain steady output current 158 Model Aviation DC-3 1140 Span$4200 F4U CORSAIR2% Span$3000 ASMS ZERO2% pan$3000 CURTIS P402% Span$3000 AT-S TEXAN24 Span$3000 F8FBEARCAT2% Span$3000 FOKKERDR-127 Tripa$2700 Whip Antenna Gives Hidden Performance Thus some reason chosen value charge current should rise such auto engine started alternator causes auto battery voltage rise transistor control circuit instructs charger electronics lower its output maintain steady charge Similarly some reason charge current should drop such due rising voltage battery being charged lower sampled current sensed transistor re adjusts desired value hap pens quickly quietly automatically graphs show typical charger output current behavior both original modified versions As function other added components resistor R5 prevents exces sive damaging current flowing transistor base R6 Cl C2 Dl perform filtering functions com bined original new electronics work together properly Resistor R7 terminal strip makes up missing pot originally circuit Using modified Super Charger very much like using unmodified version suggest turn current control down minimum select range switch setting correspond number cells being charged Connect charger clips auto battery output cable model battery Turn timer switch fully clockwise set current control knob desired current meter reading Thats Thoughts suggestions Essentially needed information modifying charger given photos captions some additional offerings considering modification Several chargers have modified using information have worked billed effort has made assure satisfactory operationincluding extensive field testing accounts delayed article should clear task beginner also should easy straightforward reasonable skill relevant experience may notice charger current varies whenever operating transmitter brought within close proximity natural consequence radiated signal interfering charger electronicsso dont worry dont either natural consequence using charger assured constant-timed current flights same profile will become remarkably uniform duration particularly noticeable sport aerobatic models Sailplanes absence thermal activity has become routine experience con secutive aerobatic flights having nominal durations about five minutes clock within just few seconds other Finally no doubt have already thought realize other modification will void product .EEEEEEU SEe GLOW FUEL MANUFACTURED WITH THE PUREST FINEST QUALITY INGREDIENTS AVAILABLE * Superior Igniters Improve starting idle acceleration Youll notice power bargain fuels * Special Detergents Promote clean burning prevent residue buildup * Rust Inhibitors Protect engines corrosion After run oil needed engines * Film Strength Additives Increase lubricity provide extra lean run protection * Anti-Wear Additives Help keep engines running peak performance longer * Satisfaction Guaranteed SIG CHAMPION 2-STROKE FUEL FREIGHT FREE SHIPPING ON ORDERS OVER $1500 COLLECT PINTQUART GALLON55 GAL DRUM 0%Nitromethane$315$450$1050$19000 5%Nitromethane$365$525$1250$25800 10%Nitromethane$415$550$1450$32500 15%Nitromethane$430$625$1650$38500 25%Nitromethane$495$750$2095$52000 35%Nitromethane$575$875$2495$66000 SIG PREMIUM4-STROKE FUEL 10%Nitromethane$415$550$1395$29500 15%Nitromethane$425$625$1595$35900 THECHOICE OF CHAMPIONFLYERS over 20 years SIG has blending finest quality model engine fuel available using finest quality ingredients instance Methanol use 995% pure very best grade money can buy also use real 100% pure Nitromethane get full measure youve paid based honest percentage-of-volume method percentage weight SIG fuels con tain 50-50 blend Bakers purest AA Castor Oil new improved Klotz Techniplate Synthetic Racing Oil maximum engine lubrication protection Based experience sincerely believe finest quality fuel can made price dont take word try some judge 1111111 N iuii BROWN JR CAMPBELL COMET COVERITE COX EASY BUILT MODELS ENYA- FAt INE Fox GOLDBERG- GOLDEN AGE REPRO GENE DUBOIS GUILLOW- K&B K&S L R MRC OS MAX PACTRA PECK-POLYMER PERFECT R/N MODELS SEAGLEN SIG STERLING SULLIVAN SUPER TIGRE TAFFINDER TELCO- TOP FLITE- TREXLER WILLIAMS & OTHERS ESTES MODEL ROCKETS Send $100 Cash Check Stamps 44 page tahlold sire DISCOUNT Catalog 900 illostrations osrr 700 Kits choose MAILORDER PIIONEORDER IN STORE PENN VALLEY DOUBT CENTER 137 1 Kain 3t Lanidalmla 19441 September1987 159 TKieeha11 RIC 1db-Bar Glow Plugs Long orOnly $189 Also. Traditional line non-idle bar Glow Plugs Six Types 3 Heat Ranges High Performance Glow Element Blow Proof Seal Only $149 Swanson Associates PO Box 151 Since 7948 Wayne NJ 07470 warranty Just know Good luck charger modifi cation Im sure youll find stable reliable charge current affords well worth small effort cost needed achieve Happy Silent Flying Electrics Please forward comments ques tions SASE please author Bob Kopski 25 West End Dr Lansdale I When responding advertisers mention read about ModelAviation JET ENGINESSALE DYNAJETS $19900 Catalog $500 AL TOmE 4015 Ban Jacjsxto # 404 0 Houston Texas flOO4 p13 4404744 WANNA RACE NARTHFAT ARFA* BEGINNER RACESr Q-500 * FORM-i * FAI Instructions Club Programs informatiot Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVE FRANKLIN MASS 02038 Tel 617 528-4043 203 673 -2000 PA 19446 Parts List Radio Shack PartDescriptionPt No Ri1 ohm 10 watt resistor271 131 R21 ohm 10 watt resistor271 131 R322 K ohm resistor271 1325 R410 Kohmcontrolpotorig inal charger output control R51 K ohm resistor271 1321 R61 K ohm resistor271 1321 R715 K ohm resistor271 1337 Cl1OuF35VTantalum2721434 capacitor C2 22 uF 16 V Tantalum 2721437 capacitor 01 PNPtransistoranyoneof MP52907 M PS3638 2N2907 2N2907A 2N3906 Dl Silicon diode 1N914 1N4148 1 N4454 Miscellaneous PC Holeboard cut from 276 170 Terminal strip made from274 688 Wire Ace RC similar required 3/1 6in inside dia star washer Auto battery clips large 270 344 Six ft white 18-gauge lamp cord optional Solder required EpoxyDevcon 2-Ton white slow cure hardware store Time Three four hours Burt Rutan/Worth Continued page 91 discussion indicated desire part get 1987 Nats Lincoln meet old friends famous modelers After luncheon made firm Burt expected guest honor AMA banquet Wednesday Nats week AMA awards ceremony tended Burt Rutan friend Tonya Simone AMA President Don Lowe Na tional Aeronautic Association Executive Vice President Ev Langworthy AMA Executive Director John Worth Mrs Worth AMA Vice-Presidents Don Krafft District 1 Dave Brown 3 Howard Crispin 4 John Clemens 8 Dick Crowley 9 also AMA member Dave Edmonds HQ staffers Hurst Bowers Joyce Hager Geoff Styles Jeff Troy Vince Mankowski Lou Ward Doug Pratt Special guests Luther Hux wife Dawnthey provided model Voyager luncheon cen terpiece also photos article Postscript Voyager model RC flown time awards ceremony next morningfollow ing advice Burt concerning trim design factorsLuther Hux flew model successfully four times As fullscale design model flies well 276 2023a fitting follow-up evening before 276 2032when Luther said Dick Rutan Jeana Yeager During past years have flying Space Shuttle model AMA air shows Whenever landed everyone cheered watching real 2761122thing know cheers 2761122the model people flew full-scale Shuttle matter pride achieved Americans year fly Voyager model Im looking forward listening cheer CL Regionals/Hazel Continued page 94 As customary least some winning Speed flights posted Fri day Bill Nusz Lancaster CA shook up air bit fastest Class D time meet 19557 mph also turned out fastest official time event Bills ship original built Newton glass fuselage top sheet aluminum wings engine OS65 modified Glen Dye turned Rev-Up 9 x 13 prop uniflow pressure tank juiced 75% nitro fuel youre hot youre hot Bill man aged put up fastest official Jet time Friday well posting 19264 mph Super Burp design Model Avi ation plans #243 Hed reworked DynaJet engine along lines detailed Continued page 166 160 Model Aviation CHAMPION FF KITS Wakefield$44 95 Coupe$25 95* Wake-Up Mulvihill$2450 CHAMPION RUBBER 3/16 & 1/4 widths 042 thick $1195/lb BOx* CATALOG $100 CHAMPION MODEL PRODUCTS 880 Carmen Ct La Verne CA 91750 714 599-3348 Inclades US ddney xu UPSC4I resde,ts add 0% sates tax i UILD YOUR HELl TEST YOUR HELl AIR YOUR H ELI North 7th St ~I1 Lehighton Pa 18235 WRITE OR CALL FOR INFORMA TION ALREADY FLYING BIND NEW TRAINERS WITH RADIO AND ENGNE INSTALLED-OntyS300 FUTABA 4NLw/4S38 SERVOS S2OrTS R/G PARADISE 6089354206 660 KAUMANA Dr HILOHi 96720 PAW DIESELS Englands Finest 049 35 RIC STD S.d $100 list Eric Ciutton 913 Cedar Lane Tuliahoma Tenn 37388 CARBON MAT SAMPLE 2 OR 5 OZ/SO YD SEND $1 00 EACH TO AEROSPACE COMPOSITE PRODUCTS PO Box 16621 Ervine CA 92714
Edition: Model Aviation - 1987/09
Page Numbers: 81, 82, 83, 84, 158, 159, 160
The simple modifications described article will give Astro Model 102 charger consistent output make impervious input voltage fluc tuations allowing charge battery packs driving field EBob Kopski SEVERAL MONTHS AGO regu lar monthly RC Electrics column promised information modification Astro Model 102 DC/DC Super September 1987 81 mop xcup TUTU IOfl9Uf unarge ouro ruiuuuiuu rung ewulun uno larger Oattery clips modified charger looks very much did originally Using white 6-ft lamp cord makes convenientto hook upthe model its visible grass Switching larger clips provides better connection car batterysomething current-hungry chargers should have other mode arent made range switch relabeled Sharpie marking pen read 1-14 lower position 10-22 upperpositlon Above inside original Astro DC/DC charger pencil points originsi component thats re wiredthe controi pot White wire timer meter will replaced resistor pair FiGURE 1 Char OUTPUT CURRENT AW 7 Set Point 4A P 12V Inpi 12 Left graph shows what happens th original modified chargeroutput currents input voitage isvaried Tests included two differentbatterypacksan 8-cell 1 2Ah pack being charged onthe 1-14 cell range a20 cciii 2 Ah pack beingchargedonthe 10-22 cell range smaller pack set up charge 4 amps 12-volt input larger pack set up 3 amps same input voltage input varied up down such might happen starting running car engine easyto see improvement mod makes Right Graph depicts variation charge current tars fixed inputvoitagetothe chargerovera 1 5-minute charge cycle Two different 12 Ah packs testedan 8-cell 20-cell initial charge current time 0 set 4 amps Start Radio Shack terminal strip shown left Cut down shown right bendtheterminalsgO Solder resistor R7 shown carefully driii out mounting lug hois 3/16 Modifications should begin instal lation two 1-ohm 10 watt resistors Ri R2 resistors actually wired parallel form /rohm current-sam pling resistor Both resistors will get hot during operation very important thatthev cooxied aluminum canaL Charger modification easy stall will significantly improve performance already very fine prod uct applications Heres what its about Astro Super Charger may thought fully adjustable voltage converter effect charger can take 12-volt input auto battery change lower higher values done setting range switch adjustable control knob Thus charging pack containing few cells charger set relatively low output voltage pack has cells higher normal 12-volt car battery voltage needed charger adjusted provide Its like having variable auto battery help clear up some confusion about product subject charger 82 Model Aviation Tne terminsi strip assemmy neia piece aytne meisi-tramee inductors mounting screw Position strip clear everything Label wires pot original location can retained Remove wire pot lug nearest front photo solder right-hand lug terminal strip Remove other two wires pot soiderthem left lug terminal strip mix up FIGURE 3 Astro DC-DC Super Charger Modification Schematic Remove knob control pot remove pot front panel Solder three short wiressuch leftover resistor leadsto pot lugs run wIres through proper holes circuit board Keep board snug againstthe pot additional strength route wires through two holes circuit board bringing wire U shape back up through adjacent hole clr cult board Securely solder wire both points goes through board automaticie does sense battery charge condition shut itself off Rather has standard 15-minute timer switch control charge duration perfectly acceptable way doing things fact charging timed charge Therefore modification does change aspect chargers operation However charger also regu lated what modification about regulated sense selected battery charge current inherently stable rather varies both charge condition terminal volt age battery being charged auto battery voltage driving As consequence often necessary keep eye charge current readjust control knob during charging cycle Personally Im used charging stable charge current after seeing well Astro 102 otherwise performed began wonder about modifying September 1987 83 two connectons REPLACE existing wire NOTE All components shown pcholeboard subassembly except Ri R2 panel Ri terminal strip /Ri lOw SOLDER TOSOLDER TO UPPER TERMINAL1L--V\/\J~J ILEFT TERMINAL OF TIMER-SWITCHI P2 lOwJOF AqIETER GREY ORANGER3 22kR4 10k Original Control Pot CW ROTATION Increases Output P51kN TERMINAL STRIP TRANSISTOR QiDETAIL Cl luf35v R6lk YELLOWII II15k WIRE DIODE DlCZ 2Zuf iSvK YELLOW WIRE TO LEFTGREEN WIRE TO ORIGINAL LUG OF ADDED TERMINALCHARGER CIRCUIT BOARD STRIP RiSee photo 8 WIRES FROM ORIGINAL CIRCUIT BOARD--ORIGINALLY CONNECTED TO CONTROL POT simple circuIt addition needed stabilize charge current limited number re quired parts makes easy task some soldering experIence very important work carefully correctly because mistake could damage charger FIGURE 4 Astro DC-DC Super Charger Modification uit Board Pictorial SPECIAL NOTE LEADS VARY--SO BE SURE YOUR TRANSISTOR CEB LEADS GD TO CORRECT LOCATIONS COLLECTOR GREEN WIRE TO OIARGER CKT BOARD YELLOW WIRE TO TERMINAL STRIP EMITTER BASE P3 THIS PICTORIAL IS TOP VIEW R4 control pot 9 QI JtLr7JDlCi//R5 JORANGE WIRE TO TIMERSWITCH ALL DOTTED VERTICAL LINES INDICATE FOIL CONNECTORS ON CIRCUIT BOARD SPECIAL NOTE PC-HOLE BOARD MUST BE CUT TO SIZE WITH SHOLE CONDUCTOR PATTERN LOCATED BETWEEN THESE ARROWS BOARD IS 17 HOLES WIRE TO PANEL METER Almost circuit modification components assembled small piece circuit board wire leads identif led color used original assembly may change colors change wiring locationsbe sure what doingi Attach green wire directly original charger circuit board underneath large metal-framed inductor wire colors mentioned throughout procedure reference four distInct colors could usedbut dont mix up locational Install other components nns circume ~ardasshownintheassembiydrawing careful get capacitor diode polarities correct Make sure transistor leads inthe approprIate iocationssomett5n515t0r choices have leads different locations Connect 6-in lead-out wires shown Standard RC wire Ace RC okay include output current stabilization article result pursuing idea simple additional circuitry described herein makes selected charge current much stable Once set have readjust charge value over 15-minute timer period best part about charging can done auto engine running can arrive field ready fly See Model Avi ation March July 1985 Just re member attempt charging batteries driving car modi fication could disastrous since input voltage variation occurs car runmng causes similar tremendous vari ation charger output current course everything else life somethings just gotta wrong thing sounds goodright Yup four disadvantages associated modification First circuit modification reduces two maximum number cells could otherwise charged cause added circuitry uses some available charger output voltage makes unavailable battery being charged Second modified charger uses slight ly current auto battery runs somewhat hotter result charger output current flowing through added sampling resistor R1-R2 have found no ill effects because Third trickle charge now unadjust able Ordinarily small trickle charge current can set charger timer off As rule never trickle charge anyway besides coarse scale meter doesnt permit readable values such low currents begin withso doesnt bother fourth disadvantage drawback under particular set circum stances Ill call fourth difference modification output current charger cannot turned completely zero lowest output about 12 amps control knob adjusts upward woukl disadvantage wanted charge very small cells such 250 mAh smaller Now feel youd like have described advantages can somehow make through life disadvantages read See works easy modiir Astro DC/DC Super Charger added circuItry charger modi fication consists assembling small circuit board usjng Radio Shack parts installing new subassembly DC/DC Super Charger changes original charger minimal re versibleso should ever want change back can original charger parts used onethe control pot wires rewired have follow sketches photos exactly work carefully Continued page 158 84 Model Aviation FIGURE 5 Astro DC-DC Super Charger Modification Misc Pictorial Details GREEN WIRE SI LITE t1Ii LAD IBITTED ORIGINAL POT WIRING SOLID RE-cONNECTIONS REItJVE add RI-R2 R2 WI RE REAR VIEW Left Pay particularattentlon rerouting wires original potentiometer mistake will cause extensive damage original charger circuit Right Parailel resistors Ri R2 replace wire orIgInally connecting panel meter timer switch Use short lengths 1 8-gauge lamp cord extend resistor leads required Ri R2 must epoxy-giued aiuminum panel heat-sink cooling purposes ORIGINAL CIRCUIT BOARD wider inductor V 0 inside completed sin u uiirur mmmi resistor ana wire going ins pilOt light should removed since InC trickle-charge circuit no longer functions original Reinstalithe control potwlth its newcircultboard attached intotheoriginal panel location Position circuit board clears everything Tighten pot mounting nut Reinstall control knob making sure pot turned fully CCW pointer t 7 n,lnk Trim fin. wire fr irnh -"er appropriate destinations PRACTICAL SIZED GIANT Order Canopies Available Plans sent Post-Paid within USA Send 5Oe Full Catalog Balsa Nick Ziroli 29 EdMar Dr Smithiown NY 11787 USA MODELS NICK ZIROLI Jets too Plans RK-20 RK-740 Ducted Fans Phantom38 span$1000 Viggen32 span$1000 F-1538 span$1000 Plan canopy$1500 516-234-5038 enclosing some photos modifications K&B 15 definitely improve ground rpm engine resulting airspeed As can see photograph stock crank left crank right has enlarged extra meat has taken out shaft area addition venturi has enlarged some 015 second photograph shows enlarge ment venturi well giving view back crank can see enlarged hole extra meat removed up near timing area particular cranks close around 620 after top dead center ATDC Ron Youngs Performance Engines will rework cranks you can make modifica tion yourself Ron indicates enlarged crankshaft K&B/Cox 15 will flow approximately 30% air through engine minimum 500 rpm gain test stand Racing tank refueling procedures Several Gone forever nightmare heli-flier dreads stepping 3 foot tenna ripping off front prized chopper just ifs ready fly Base loaded short WHIPANTENNA f iveshidden performance Less 7 ong can mounted project front helicopter inside canopy ts virtually invtsible cZv~ 00R0A54 MODEL PRODUCTS 23961 CRAFTSMAN RD CALABASAS CA 91302 818 992-0195 218 VERNON ROAD GREENVILLE PA 16125 412 588-1321 competitors have written asking prevent damage fuel tank fill tube during hasty pit stop tube occasionally pushed down quick-fill too far rams hole bottom tank Ron Esman Texas Racing contingent found soldering small ring onto neck fuel filler ring prevents fill tube going too far tank Also size ring prevents fuel squirting back pit mans face deflects spray either side aircraft ring can easily fabricated large washer soldered place after measuring length tube enters tank Mouse Racing Al Lidberg Tempe AZ has sent some plans Annie Mouse Racer particular aircraft flies very well has very successful local competition flying area am including plan months column am sure would like further information can write Al Lidberg 614 W Fordham Tempe AZ 85283 St Louis alive well just talked Gary Frost St Louis area indicated both flying field club both excellent health Gary planning early October contest 87 people have written asked what happened St Louis will understand contest schedule once again reinstated major problem Buder Park flying site last summers contest schedule interruption park used horse shows instead model airplanes Gary assures has rectified 1987 fine Midwest site should again scene fine annual meet AMA records Racing received several requests mentioning Racing events being cluded AMA National Records As talk AMA district representatives both VP CL Contest Board please men tion Racing contingent would like have AMA records Racing events am sure voice heard something will done F2C Team Racer drawings have over dozen requests six sets plans Russian TRs. have sent copies everyone requested anyone else might have missed column still have several copies left will happy forward As always comments photographs appreciated John C Ballard 10102 Kimblewick Dr Louisville KY 40223 Charger/Kopski Continued page 84 dont feel comfortable confident sol dering get someone help works Space does permit detailed discussion technical details circuity operation Id like least pass along brief explanation basic idea involved As mentioned above although DC/DC Super Charger fully adjustable may provide stable charge current because set value current part dependent certain conditions external charger modification presented corrects adding internal reference charge current feedback circuit au tomatically adjusts charger operation output current should stray chosen value Referring schematic modified charger output current flows through ohm sampling resistor RL-R2 voltage appearing across resistance directly proportional charge current small circuit-card subassembly contains PNP transistor base-emitter junc tion watches voltage Adjustable divider R3-R4the new current control selects portion R1-R2 voltage application transistor Note R4 rewired original 10K control plus range switch still used adjust desired output current collector transistor con nected original electronics charger control pot origi nally wired effect transistor comes new controlling device original circuit happens because transistor collector will conduct current base emitter junction does So depending setting R4 sampled charge current causes about 06 volts often called VBE Threshold used voltage reference appear base-emitter junction tran sistor collector applies control signal original location adjustment control done way maintain steady output current 158 Model Aviation DC-3 1140 Span$4200 F4U CORSAIR2% Span$3000 ASMS ZERO2% pan$3000 CURTIS P402% Span$3000 AT-S TEXAN24 Span$3000 F8FBEARCAT2% Span$3000 FOKKERDR-127 Tripa$2700 Whip Antenna Gives Hidden Performance Thus some reason chosen value charge current should rise such auto engine started alternator causes auto battery voltage rise transistor control circuit instructs charger electronics lower its output maintain steady charge Similarly some reason charge current should drop such due rising voltage battery being charged lower sampled current sensed transistor re adjusts desired value hap pens quickly quietly automatically graphs show typical charger output current behavior both original modified versions As function other added components resistor R5 prevents exces sive damaging current flowing transistor base R6 Cl C2 Dl perform filtering functions com bined original new electronics work together properly Resistor R7 terminal strip makes up missing pot originally circuit Using modified Super Charger very much like using unmodified version suggest turn current control down minimum select range switch setting correspond number cells being charged Connect charger clips auto battery output cable model battery Turn timer switch fully clockwise set current control knob desired current meter reading Thats Thoughts suggestions Essentially needed information modifying charger given photos captions some additional offerings considering modification Several chargers have modified using information have worked billed effort has made assure satisfactory operationincluding extensive field testing accounts delayed article should clear task beginner also should easy straightforward reasonable skill relevant experience may notice charger current varies whenever operating transmitter brought within close proximity natural consequence radiated signal interfering charger electronicsso dont worry dont either natural consequence using charger assured constant-timed current flights same profile will become remarkably uniform duration particularly noticeable sport aerobatic models Sailplanes absence thermal activity has become routine experience con secutive aerobatic flights having nominal durations about five minutes clock within just few seconds other Finally no doubt have already thought realize other modification will void product .EEEEEEU SEe GLOW FUEL MANUFACTURED WITH THE PUREST FINEST QUALITY INGREDIENTS AVAILABLE * Superior Igniters Improve starting idle acceleration Youll notice power bargain fuels * Special Detergents Promote clean burning prevent residue buildup * Rust Inhibitors Protect engines corrosion After run oil needed engines * Film Strength Additives Increase lubricity provide extra lean run protection * Anti-Wear Additives Help keep engines running peak performance longer * Satisfaction Guaranteed SIG CHAMPION 2-STROKE FUEL FREIGHT FREE SHIPPING ON ORDERS OVER $1500 COLLECT PINTQUART GALLON55 GAL DRUM 0%Nitromethane$315$450$1050$19000 5%Nitromethane$365$525$1250$25800 10%Nitromethane$415$550$1450$32500 15%Nitromethane$430$625$1650$38500 25%Nitromethane$495$750$2095$52000 35%Nitromethane$575$875$2495$66000 SIG PREMIUM4-STROKE FUEL 10%Nitromethane$415$550$1395$29500 15%Nitromethane$425$625$1595$35900 THECHOICE OF CHAMPIONFLYERS over 20 years SIG has blending finest quality model engine fuel available using finest quality ingredients instance Methanol use 995% pure very best grade money can buy also use real 100% pure Nitromethane get full measure youve paid based honest percentage-of-volume method percentage weight SIG fuels con tain 50-50 blend Bakers purest AA Castor Oil new improved Klotz Techniplate Synthetic Racing Oil maximum engine lubrication protection Based experience sincerely believe finest quality fuel can made price dont take word try some judge 1111111 N iuii BROWN JR CAMPBELL COMET COVERITE COX EASY BUILT MODELS ENYA- FAt INE Fox GOLDBERG- GOLDEN AGE REPRO GENE DUBOIS GUILLOW- K&B K&S L R MRC OS MAX PACTRA PECK-POLYMER PERFECT R/N MODELS SEAGLEN SIG STERLING SULLIVAN SUPER TIGRE TAFFINDER TELCO- TOP FLITE- TREXLER WILLIAMS & OTHERS ESTES MODEL ROCKETS Send $100 Cash Check Stamps 44 page tahlold sire DISCOUNT Catalog 900 illostrations osrr 700 Kits choose MAILORDER PIIONEORDER IN STORE PENN VALLEY DOUBT CENTER 137 1 Kain 3t Lanidalmla 19441 September1987 159 TKieeha11 RIC 1db-Bar Glow Plugs Long orOnly $189 Also. Traditional line non-idle bar Glow Plugs Six Types 3 Heat Ranges High Performance Glow Element Blow Proof Seal Only $149 Swanson Associates PO Box 151 Since 7948 Wayne NJ 07470 warranty Just know Good luck charger modifi cation Im sure youll find stable reliable charge current affords well worth small effort cost needed achieve Happy Silent Flying Electrics Please forward comments ques tions SASE please author Bob Kopski 25 West End Dr Lansdale I When responding advertisers mention read about ModelAviation JET ENGINESSALE DYNAJETS $19900 Catalog $500 AL TOmE 4015 Ban Jacjsxto # 404 0 Houston Texas flOO4 p13 4404744 WANNA RACE NARTHFAT ARFA* BEGINNER RACESr Q-500 * FORM-i * FAI Instructions Club Programs informatiot Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVE FRANKLIN MASS 02038 Tel 617 528-4043 203 673 -2000 PA 19446 Parts List Radio Shack PartDescriptionPt No Ri1 ohm 10 watt resistor271 131 R21 ohm 10 watt resistor271 131 R322 K ohm resistor271 1325 R410 Kohmcontrolpotorig inal charger output control R51 K ohm resistor271 1321 R61 K ohm resistor271 1321 R715 K ohm resistor271 1337 Cl1OuF35VTantalum2721434 capacitor C2 22 uF 16 V Tantalum 2721437 capacitor 01 PNPtransistoranyoneof MP52907 M PS3638 2N2907 2N2907A 2N3906 Dl Silicon diode 1N914 1N4148 1 N4454 Miscellaneous PC Holeboard cut from 276 170 Terminal strip made from274 688 Wire Ace RC similar required 3/1 6in inside dia star washer Auto battery clips large 270 344 Six ft white 18-gauge lamp cord optional Solder required EpoxyDevcon 2-Ton white slow cure hardware store Time Three four hours Burt Rutan/Worth Continued page 91 discussion indicated desire part get 1987 Nats Lincoln meet old friends famous modelers After luncheon made firm Burt expected guest honor AMA banquet Wednesday Nats week AMA awards ceremony tended Burt Rutan friend Tonya Simone AMA President Don Lowe Na tional Aeronautic Association Executive Vice President Ev Langworthy AMA Executive Director John Worth Mrs Worth AMA Vice-Presidents Don Krafft District 1 Dave Brown 3 Howard Crispin 4 John Clemens 8 Dick Crowley 9 also AMA member Dave Edmonds HQ staffers Hurst Bowers Joyce Hager Geoff Styles Jeff Troy Vince Mankowski Lou Ward Doug Pratt Special guests Luther Hux wife Dawnthey provided model Voyager luncheon cen terpiece also photos article Postscript Voyager model RC flown time awards ceremony next morningfollow ing advice Burt concerning trim design factorsLuther Hux flew model successfully four times As fullscale design model flies well 276 2023a fitting follow-up evening before 276 2032when Luther said Dick Rutan Jeana Yeager During past years have flying Space Shuttle model AMA air shows Whenever landed everyone cheered watching real 2761122thing know cheers 2761122the model people flew full-scale Shuttle matter pride achieved Americans year fly Voyager model Im looking forward listening cheer CL Regionals/Hazel Continued page 94 As customary least some winning Speed flights posted Fri day Bill Nusz Lancaster CA shook up air bit fastest Class D time meet 19557 mph also turned out fastest official time event Bills ship original built Newton glass fuselage top sheet aluminum wings engine OS65 modified Glen Dye turned Rev-Up 9 x 13 prop uniflow pressure tank juiced 75% nitro fuel youre hot youre hot Bill man aged put up fastest official Jet time Friday well posting 19264 mph Super Burp design Model Avi ation plans #243 Hed reworked DynaJet engine along lines detailed Continued page 166 160 Model Aviation CHAMPION FF KITS Wakefield$44 95 Coupe$25 95* Wake-Up Mulvihill$2450 CHAMPION RUBBER 3/16 & 1/4 widths 042 thick $1195/lb BOx* CATALOG $100 CHAMPION MODEL PRODUCTS 880 Carmen Ct La Verne CA 91750 714 599-3348 Inclades US ddney xu UPSC4I resde,ts add 0% sates tax i UILD YOUR HELl TEST YOUR HELl AIR YOUR H ELI North 7th St ~I1 Lehighton Pa 18235 WRITE OR CALL FOR INFORMA TION ALREADY FLYING BIND NEW TRAINERS WITH RADIO AND ENGNE INSTALLED-OntyS300 FUTABA 4NLw/4S38 SERVOS S2OrTS R/G PARADISE 6089354206 660 KAUMANA Dr HILOHi 96720 PAW DIESELS Englands Finest 049 35 RIC STD S.d $100 list Eric Ciutton 913 Cedar Lane Tuliahoma Tenn 37388 CARBON MAT SAMPLE 2 OR 5 OZ/SO YD SEND $1 00 EACH TO AEROSPACE COMPOSITE PRODUCTS PO Box 16621 Ervine CA 92714