SNOWED under Doctor Jim Pepino responsi bleand office full paper latest Care package Scale Plans & Photo Ser vice 3209 Madison Ave Greensboro NC 27403 just arrived large red mailing tube brought door friendly mailman con tained three Doc Jims latest Giant Scale draw ings included deHavilland Chipmunk two cockpit configurations beautiful Fairchild PT-19 including mods fullcanopy version Waco YMF-7 Golden Age biplane three drawing sets bear evidence Jims excellent draftsmanship exhaustive scale re search example always provides accurate-documentation three-views right plans notes degree construction difficulty builder will know what getting before first bit spruce balsa cut Other nice touches include recommenda tions suitable engines tabular indication wood sizes types required complete model Finally Doctor Jim contracts better fi berglass parts manufacturers provide cowl ings wheel pants other difficult-to-build parts designs Man wish time build Wacoits absolutely gorgeous phone has ringing off hook lately Nine long distance calls Out 10 enquiries about suitability particular Giant Scale en gines specific model designs Although drawings scratch-building include engine rec onunendations seem need addi tional assurance particular power plant will adequate Unfortunately bunch misinforma Pat Massey Pampa TX justly proud scratch-built Aeronca KCA Power OS Ge mini 16 Cu twin-cylinder four-stroke Photo Below shows scale details cluding spring-loaded floating gas gauge just ahead windshield rivets addition baf fling false exhaust headers OS closely duplicate full-scale installation Func tional cowl latches allow cowling removed easily engine servicing Photo next page R shows completely detailed cockpit complete dual controls instrument pa nel Seats padded upholstered full-scale ship tion misconception floating around out particular model Lets consider representa about engine use Such confu- tive list sion understandable because host factors go choosing power plant l flying weight 40 Model Aviation Radio Control Giant Scale John de Vries Colonel USAF Ret 4610 Moffat Ln Colorado Springs CO 90915 Don Piatt Pampa TX built fine pair models Rearwin Speedster L Great Planes kit Sig Morrissey Bravo R Rearwin weighs 17 lb uses OS 120 power Its color scheme predominantly red Bravo uses Supertigre 3000 power weighs 19 lb general considering practical rules-ofthumb factors influence engine choice following ways Probably most-used criteria engine se lection projected weight finished mo del Experts have suggested Giant Scale mod els 15- 20-lb range should use smal ler two-cubic-inch gas burners models weighing 20 35 lb engines repre sented Quadra Q-50 suitable birds 35 lb up AMA maximum weight limit talking big Kawasakis Sachs Dolmars other muscular engines rule considering wing area volume seems squares cubes larger powerful engine should isnt strictly true because bigger birds fly wing rather en gine Wing loading may better factor con sider High wing loadings expressed ounces per square foot require powerful hum mersto help keep airspeed up Aerodynamic drag must overcome models power plant Smooth slick models like Lasers Warbirds lot less draggy fully rigged biplanesand can get slightly less noise engine compartment Big engines equal heavy engines Giant comes Out tail-heavy cure may stick heavier engine onto firewall Admittedly may scientific way locate mod els CG properly lot model builders go route lot us figure paid 40 bucks engine servo isnt substitute cubic inches After can always pull throttle back cant array engines available Giant Scale Continued page 128 Hundreds unusual tools borrowed tile Jewelr Gunsmithing Clock Making professional Making trades NOW AVAILABLE TO YOU BY MAIL guaranteed II use coupon sena name anoress $100 MICROMARK 340-531 Snyder Ave Berkeley Heights NJ 07922 ADDRESS L hZIPJ 410246-60 10604160041-60 1960 w140401cobadaOrlOd 410 a4160160011600CAIIOIEWlW0S wiaenoBO&lS54141laWAClS Most versatile mufflers ever offered 0 Designed fit inside cowls wIth limIted space can also used HELICOPTERS BOATS 0 For UPRIGHT INVERTED SIDE mounted engInes 0 Exhaust tubes point almost direction 0 Worm drive clamp universal mounting can bolted directly engine BASIC DIMENSIONS 030411 IjoO flowrl INCLuDEs Exhaust pipe extensions clamps worm drive clamp muffler alignment plate gasket mounting screws U ovo4obte hobby shOp OROEFt DIREcT Eruludote sNpment chects MO Vls Mc coo accepted Ada $250 UPS 5200 coo 6% sales cae resident jI m 164 School St Daly CIty CA 94014 415 756-3400 June 1988 41 over 1000 m1 NEW Catalog FROMI MicroMark Small Tool Specialists Model wing area/wing volume Predictable parasite induced drag Model balance Engine efficiency Engine cost availability Propeller efficiency Flight altitude Cowling Personal brand preference iWO-CYCLE IN-COWL AIRCRAFr MUFFLERS 19-4045-6075-13 engines UPRIGHT e INVERTED ENGINE J-401 19-40 itm JT-401 AS-at 19 JT-901 7513 21 Totes podntto head Eonlrroeotedeo-tglneor o4601l 01011011 boots 41-60410-AC 106041-02 19-AC 1560 41-60441-60106041-60645-60 1460 41-60411-IA 216041-406 11-132160 no10606lfflSbeWdlalFe 43101905 60011- t$l0060160S altitude about 200 ft realized absolutely no control whatsoever model went left-hand spiral dive resulting impact macadam runway drove OS 30s crankshaft Out through rear crankcase cover turned model yellow Cover ite bag balsawood Also GI Joe pilot lost headbut lived fly again Other having stripped gears servos radio functioned flawlessly after crash So theory about loss control partially disconnected receiver battery pack stuffed rearward tempt shift CG time didnt bother tape radio connectors engine vibration took care rest disconnection So never did find out whether rearward CG shift would have improved J-3s spin entries did learn secure connectors tape fu ture models fly alone fly alone number readers sent letters commented Plane bites man story March 1988 column concerned incident modeler struck seriously injured own plane advice also Never fly alone Apparently lot out dont subscribe advice Most seem feel because no flying site wont suffer injury loss model because someone elses mistake Similarly mistake does jeopardize someone elses safety may true being hit model frequent cause injury Feeding fingers through own models prop com mon cause injury Driving car hand easy may impossible other hand being used stop flow blood Flying untested Scale models recent letter Del Rykert Batavia NY expressed con cern about numerous occasions wherein has seen modelers enter Scale contest model hadnt tested airworthiness Del asked opinion prevent such flagrant violation safety Unfortunately didnt have simple solution offer Del thinks Scale modelers reluctant test fly new model prior entering contest cause want save static judging such case suggests solution may reverse current order judging such fly first have static judging last As stated response Del dont have good feel prevalent problem Thats Im mentioning asking input Scale modelers have real safety problem untested models being flown Scale contests what solution MariahlTriebes Continued page 33 ing point may wish adjust bal ance fit own flying style come accustomed Mariah Sailplane likes fly fast smooth Mariah has full aerobatic cap abilities extremely stable aircraft speeds swept wing keeps plane highly stable during slow flight slows down very well landing need spoilers flaps said done impor tant thing have funand some exhilarating slope flying Ive experi enced has little Sailplane Mariah may best Soarer Ive ever flown shes definitely right up first rank Try yourself youre bound agree Radio Technique/Myers Continued page 36 can accurate enough find transmitters outside AMA frequency tolerances comes measuring power levels really isnt good enough installing Gold Silver stickers paragraph 322 AMA Guidelines requires spectrum analyzer used purpose think ICOM good enough reveal illegal crystal swappingand Contest Director really wants know about RC Giant Scale/de Vries Continued page 41 bewildering Some efficient othersthey convert same amount gas glow fuel power per cubic inch Thus some installations may able get away smaller engine just because efficient others its displacement range too hobby shops distributors carry available engines engine choice may depend availability cost factors other considerations proper propeller can make break spe cific engine great prop efficiency viewpoint may turn competent engine raging tiger Flight altitude included list engine choice factors primarily because its BIG amongst us Rocky Mountains Just cause fly altitudes 5000 7000 ft above sea level know going lose 20% engines power before props spun Conversely fly sea level en gine going put out its full power Since concerned scale outlines ten engine choose determined de sire keep within confines cowling best criteria lot us dont like bunch iromnongery disrupting scale lines models Hence inclined choose physically smaller engine might appropriate power-required view point Finally often consideration brand loyalty weve successful product particular manufacturer dined buy another engines Nothing wrong criterionas long favor ite manufacturer produces range power plants Andyou can choose suitable model Engine choice very personal thing can listen pronouncements experts theyre frequently right can follow rec ommendations models designerafter hes flown model specific engine size push comes shove youll have de cide engine use youll have early building sequence Itll take lot thought consideration final note may interest movers shakers AMA clubs IMAA chapters Jim Jennings Jennings Trophy Sales PO Box 1121 Hendersonville 128 Model Aviation ZIVIA Name Street Addreas City StateZip HoWW RNATIONAL INC AbIELWLiW WE ARE SHOOTING DOWN NIGH BALSA PRICES WITH SUPER QUALITYI Satisfaction Guaranteed Direct Only ULU SHUTS 36 41 30 1162 33 3322 40 1/8 243 316248 14 2 58 132337 120337 1163 374931 332k 3445637 18 3547146 3/163628255 1/4 3738561 516385110 3/8 38612471 1/2 3110155 3/4 3165191 1/164587648 3/324 7094 56 1/6 460106 66 9164 93122 75 1/4 4110134 64 3/8 4165225139 1/2 261 MATCHED SHEETS 42 3324100 164106 3164120 144131 3ALU STICKS 3645 1/16 1214 3/32 1410 3/32 3812 332 11216 19 606 16 141116 1/6 361216 1/8 121924 3/163/161116 316 3/61720 315 122230 14 141624 1/4 361926 1/4 1/22130 14 343444 1414055 5/165162126 3/8 382737 3/8 123246 36 3/44255 3/615270 12 1123653 12 344662 1/215678 5/6 584865 34 3/46780 BALSA HOT LINE Cell SOs 7454394 lOem-& pm Central Time LONE STAR MODELS 1623 57th St Lubbock IX 79412 F SAL BA TRIANGLES 36 141/425 3/83630 1/21/235 343445 155 BALM PLANKS 36 1185 12150 13200 14280 1123275 1124360 22225 23325 24435 33495 34668 TAPERED SHEETS 36 1/4265 1/4385 36269 3/6398 1/23120 LONE STAR EPOXY 9,Lit.895 5r,i596 30 ri596 CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa LIGHT 4-6 LB WOOD36 1/323 /203 /163 323 56 183 163 43 /63 115 1/23 139 343 220 13 300 1164 32 4 /64 100 3/164 117 1/44 139 364 207 1/24 282 TRAILING EDGE 36 1/4132 5161 1439 361 1/246 1/2270 INSTANT IL UE 1, Thck 296 1 oTh, 296 2 Thick 550 2, 75/ 556 BASSWOOD45 3/163/1626 3/161/430 3/163/839 3/161/246 3/163/460 1/41442 143649 143460 3/63860 3/61/270 3/63490 1/21/290 1/234100 BUNDLE DEALS 20-116336685 201164361020 203/32 33684 15332 436955 151/6336715 104/6436675 153/16336900 103/16436810 101/4336630 101/4436690 103/8 336650 536439625 51/2336540 51/24361055 103/32448645 51/8448465 5-316 448565 514448625 * NEW * Hundreds new sizes accessories finishing materials Send #10 SASE latest catalog SPRUCE STICKS 36 41 181/81522 181/41824 1/93/82029 316 3/162534 1/4 1/43145 14 3/83650 1/41/24565 3/6 3/64563 3/61/25570 1/2X 1/26060 1/2346868 SPRUCE TRIANGLES 3/8 3/8 1/2 1/2 34 34 1/8 6 1/612 1/412 HARD MAPLE 143/8 36 812 3934 12 34 B 40 45 50 58 59 BIRCH DO WELS36 1809 31611 1414 51625 3532 3PLYBIRCH41 6412630 13212445 11612455 812450 SPLYBINCH 3/2212 1/612 3631612 45l/4X12 013/812 1/2412 41 596 625 625 625 725 900 LITE PLY 41GROOVED LG MOUNTS 13 Inches 1503/83/4/1/8/40 3003/83145/32/40 4751/234l3/16/45 Cost 45 Handling Charge W pay UPS Add $250 COD $300 extra PP APO FPO Statee accept Visa Master Card persosal check, COO 60051 Ia, Te6s US Curr600y Mirmm Wacd Order 51000 V TN 37075 producing some pretcy sporty aero modeling trophies awards engraves em free has club/chapter insignia duplication service chatll produce distinctive prizes con tests fly-ins catalog $2and well worth youre CD looking crophies Jims prices reasonable well flying season beginning across country seems like good time co interrupt readingso can go out fresh air FLY Back atcha next month RC Electrics/Kopski Continued page 43 switches favorites arming switches just arent available current ratings consistent large 20 amps todays mo tors draw would seem Well worry Ive using miniature toggle switches rated between five 10 amps years no problems fact manufacturers know supply systems too Ex amples include Astro DSC five amps Kyosho six amps So low ratings work OK higher currents answer lies partly operative word arming As explained referenced article arming switches like main switches power systems also clude radio-operated power controls like elec tronic switches relays speed controls latter devices operate radio command ultimately control power flow battery motor arming switch simply enables circuit power controls free intended job Thus arming switch first turned radio-operated controls normally still Off no power flows motor through tog gle switch other words arming switches switch cold used activate power flow RC devices Used way tiny light toggle switches take very little electrical abuse contacts simply subjected arcing spark ing would case alone controlled motor power As result quite fail ure-free case despite fact motor current ultimately flows through can exceed ratings factor three five times what about same switches used primary OnIOff control motor power such servo driven An other good question certainly true latter application quite abusive No doubt about have used small toggles way too guess what work pretty good BUT unlike used arming switches have fail direct control appli cation Such failures take form erratic intermittent operation and/or considerable ohmic loss latter always results switches getting quite warm hot occurrences notwithstanding usu ally give good service flights before such symptoms show up can re placed coo great expense course in-flight failure always possibility should pose coo serious problem planes pilots So againnot worry asked about index Electric columns seems reader cuts saves articles say finds difficult find something remembers having seen some time along way have no current index avail able time Ive thinking about de veloping last time column listed index September 85 issue covered writings beginning Septem ber 83 Look update index later year Some reader feedback March 88 column concerning new Astro 02/035 gear drive has come column described new Part No 4046 all-metal gear drive fits ferrite 05 motors well intended As tro cobalts gear drive very similar As tro drives recent years larger cobalt mo tors very rugged should solve problems associated small A-in output shafts used other 05 drives reader has told replacing drive Leisure LT 50 motor Astro part biggest problem encountered doing getting old pinion small gear off motor shaft As suggestion try first covering open ings front end bell tape care fully slit gear between teeth Dremel tool cutoff wheel can done several places desired pinion gear can split off motor shaft nutcracker tool suspect slit gear could also opened up just about kind driving wedge such old sharpened screwdriver perhaps small chisel Whatever sure properly support motor motor shaft place jeopardy gear-splitting necessary gear Another reader question recently received Continued page 133 June 1988 129
Edition: Model Aviation - 1988/06
Page Numbers: 40, 41, 128, 129
SNOWED under Doctor Jim Pepino responsi bleand office full paper latest Care package Scale Plans & Photo Ser vice 3209 Madison Ave Greensboro NC 27403 just arrived large red mailing tube brought door friendly mailman con tained three Doc Jims latest Giant Scale draw ings included deHavilland Chipmunk two cockpit configurations beautiful Fairchild PT-19 including mods fullcanopy version Waco YMF-7 Golden Age biplane three drawing sets bear evidence Jims excellent draftsmanship exhaustive scale re search example always provides accurate-documentation three-views right plans notes degree construction difficulty builder will know what getting before first bit spruce balsa cut Other nice touches include recommenda tions suitable engines tabular indication wood sizes types required complete model Finally Doctor Jim contracts better fi berglass parts manufacturers provide cowl ings wheel pants other difficult-to-build parts designs Man wish time build Wacoits absolutely gorgeous phone has ringing off hook lately Nine long distance calls Out 10 enquiries about suitability particular Giant Scale en gines specific model designs Although drawings scratch-building include engine rec onunendations seem need addi tional assurance particular power plant will adequate Unfortunately bunch misinforma Pat Massey Pampa TX justly proud scratch-built Aeronca KCA Power OS Ge mini 16 Cu twin-cylinder four-stroke Photo Below shows scale details cluding spring-loaded floating gas gauge just ahead windshield rivets addition baf fling false exhaust headers OS closely duplicate full-scale installation Func tional cowl latches allow cowling removed easily engine servicing Photo next page R shows completely detailed cockpit complete dual controls instrument pa nel Seats padded upholstered full-scale ship tion misconception floating around out particular model Lets consider representa about engine use Such confu- tive list sion understandable because host factors go choosing power plant l flying weight 40 Model Aviation Radio Control Giant Scale John de Vries Colonel USAF Ret 4610 Moffat Ln Colorado Springs CO 90915 Don Piatt Pampa TX built fine pair models Rearwin Speedster L Great Planes kit Sig Morrissey Bravo R Rearwin weighs 17 lb uses OS 120 power Its color scheme predominantly red Bravo uses Supertigre 3000 power weighs 19 lb general considering practical rules-ofthumb factors influence engine choice following ways Probably most-used criteria engine se lection projected weight finished mo del Experts have suggested Giant Scale mod els 15- 20-lb range should use smal ler two-cubic-inch gas burners models weighing 20 35 lb engines repre sented Quadra Q-50 suitable birds 35 lb up AMA maximum weight limit talking big Kawasakis Sachs Dolmars other muscular engines rule considering wing area volume seems squares cubes larger powerful engine should isnt strictly true because bigger birds fly wing rather en gine Wing loading may better factor con sider High wing loadings expressed ounces per square foot require powerful hum mersto help keep airspeed up Aerodynamic drag must overcome models power plant Smooth slick models like Lasers Warbirds lot less draggy fully rigged biplanesand can get slightly less noise engine compartment Big engines equal heavy engines Giant comes Out tail-heavy cure may stick heavier engine onto firewall Admittedly may scientific way locate mod els CG properly lot model builders go route lot us figure paid 40 bucks engine servo isnt substitute cubic inches After can always pull throttle back cant array engines available Giant Scale Continued page 128 Hundreds unusual tools borrowed tile Jewelr Gunsmithing Clock Making professional Making trades NOW AVAILABLE TO YOU BY MAIL guaranteed II use coupon sena name anoress $100 MICROMARK 340-531 Snyder Ave Berkeley Heights NJ 07922 ADDRESS L hZIPJ 410246-60 10604160041-60 1960 w140401cobadaOrlOd 410 a4160160011600CAIIOIEWlW0S wiaenoBO&lS54141laWAClS Most versatile mufflers ever offered 0 Designed fit inside cowls wIth limIted space can also used HELICOPTERS BOATS 0 For UPRIGHT INVERTED SIDE mounted engInes 0 Exhaust tubes point almost direction 0 Worm drive clamp universal mounting can bolted directly engine BASIC DIMENSIONS 030411 IjoO flowrl INCLuDEs Exhaust pipe extensions clamps worm drive clamp muffler alignment plate gasket mounting screws U ovo4obte hobby shOp OROEFt DIREcT Eruludote sNpment chects MO Vls Mc coo accepted Ada $250 UPS 5200 coo 6% sales cae resident jI m 164 School St Daly CIty CA 94014 415 756-3400 June 1988 41 over 1000 m1 NEW Catalog FROMI MicroMark Small Tool Specialists Model wing area/wing volume Predictable parasite induced drag Model balance Engine efficiency Engine cost availability Propeller efficiency Flight altitude Cowling Personal brand preference iWO-CYCLE IN-COWL AIRCRAFr MUFFLERS 19-4045-6075-13 engines UPRIGHT e INVERTED ENGINE J-401 19-40 itm JT-401 AS-at 19 JT-901 7513 21 Totes podntto head Eonlrroeotedeo-tglneor o4601l 01011011 boots 41-60410-AC 106041-02 19-AC 1560 41-60441-60106041-60645-60 1460 41-60411-IA 216041-406 11-132160 no10606lfflSbeWdlalFe 43101905 60011- t$l0060160S altitude about 200 ft realized absolutely no control whatsoever model went left-hand spiral dive resulting impact macadam runway drove OS 30s crankshaft Out through rear crankcase cover turned model yellow Cover ite bag balsawood Also GI Joe pilot lost headbut lived fly again Other having stripped gears servos radio functioned flawlessly after crash So theory about loss control partially disconnected receiver battery pack stuffed rearward tempt shift CG time didnt bother tape radio connectors engine vibration took care rest disconnection So never did find out whether rearward CG shift would have improved J-3s spin entries did learn secure connectors tape fu ture models fly alone fly alone number readers sent letters commented Plane bites man story March 1988 column concerned incident modeler struck seriously injured own plane advice also Never fly alone Apparently lot out dont subscribe advice Most seem feel because no flying site wont suffer injury loss model because someone elses mistake Similarly mistake does jeopardize someone elses safety may true being hit model frequent cause injury Feeding fingers through own models prop com mon cause injury Driving car hand easy may impossible other hand being used stop flow blood Flying untested Scale models recent letter Del Rykert Batavia NY expressed con cern about numerous occasions wherein has seen modelers enter Scale contest model hadnt tested airworthiness Del asked opinion prevent such flagrant violation safety Unfortunately didnt have simple solution offer Del thinks Scale modelers reluctant test fly new model prior entering contest cause want save static judging such case suggests solution may reverse current order judging such fly first have static judging last As stated response Del dont have good feel prevalent problem Thats Im mentioning asking input Scale modelers have real safety problem untested models being flown Scale contests what solution MariahlTriebes Continued page 33 ing point may wish adjust bal ance fit own flying style come accustomed Mariah Sailplane likes fly fast smooth Mariah has full aerobatic cap abilities extremely stable aircraft speeds swept wing keeps plane highly stable during slow flight slows down very well landing need spoilers flaps said done impor tant thing have funand some exhilarating slope flying Ive experi enced has little Sailplane Mariah may best Soarer Ive ever flown shes definitely right up first rank Try yourself youre bound agree Radio Technique/Myers Continued page 36 can accurate enough find transmitters outside AMA frequency tolerances comes measuring power levels really isnt good enough installing Gold Silver stickers paragraph 322 AMA Guidelines requires spectrum analyzer used purpose think ICOM good enough reveal illegal crystal swappingand Contest Director really wants know about RC Giant Scale/de Vries Continued page 41 bewildering Some efficient othersthey convert same amount gas glow fuel power per cubic inch Thus some installations may able get away smaller engine just because efficient others its displacement range too hobby shops distributors carry available engines engine choice may depend availability cost factors other considerations proper propeller can make break spe cific engine great prop efficiency viewpoint may turn competent engine raging tiger Flight altitude included list engine choice factors primarily because its BIG amongst us Rocky Mountains Just cause fly altitudes 5000 7000 ft above sea level know going lose 20% engines power before props spun Conversely fly sea level en gine going put out its full power Since concerned scale outlines ten engine choose determined de sire keep within confines cowling best criteria lot us dont like bunch iromnongery disrupting scale lines models Hence inclined choose physically smaller engine might appropriate power-required view point Finally often consideration brand loyalty weve successful product particular manufacturer dined buy another engines Nothing wrong criterionas long favor ite manufacturer produces range power plants Andyou can choose suitable model Engine choice very personal thing can listen pronouncements experts theyre frequently right can follow rec ommendations models designerafter hes flown model specific engine size push comes shove youll have de cide engine use youll have early building sequence Itll take lot thought consideration final note may interest movers shakers AMA clubs IMAA chapters Jim Jennings Jennings Trophy Sales PO Box 1121 Hendersonville 128 Model Aviation ZIVIA Name Street Addreas City StateZip HoWW RNATIONAL INC AbIELWLiW WE ARE SHOOTING DOWN NIGH BALSA PRICES WITH SUPER QUALITYI Satisfaction Guaranteed Direct Only ULU SHUTS 36 41 30 1162 33 3322 40 1/8 243 316248 14 2 58 132337 120337 1163 374931 332k 3445637 18 3547146 3/163628255 1/4 3738561 516385110 3/8 38612471 1/2 3110155 3/4 3165191 1/164587648 3/324 7094 56 1/6 460106 66 9164 93122 75 1/4 4110134 64 3/8 4165225139 1/2 261 MATCHED SHEETS 42 3324100 164106 3164120 144131 3ALU STICKS 3645 1/16 1214 3/32 1410 3/32 3812 332 11216 19 606 16 141116 1/6 361216 1/8 121924 3/163/161116 316 3/61720 315 122230 14 141624 1/4 361926 1/4 1/22130 14 343444 1414055 5/165162126 3/8 382737 3/8 123246 36 3/44255 3/615270 12 1123653 12 344662 1/215678 5/6 584865 34 3/46780 BALSA HOT LINE Cell SOs 7454394 lOem-& pm Central Time LONE STAR MODELS 1623 57th St Lubbock IX 79412 F SAL BA TRIANGLES 36 141/425 3/83630 1/21/235 343445 155 BALM PLANKS 36 1185 12150 13200 14280 1123275 1124360 22225 23325 24435 33495 34668 TAPERED SHEETS 36 1/4265 1/4385 36269 3/6398 1/23120 LONE STAR EPOXY 9,Lit.895 5r,i596 30 ri596 CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa LIGHT 4-6 LB WOOD36 1/323 /203 /163 323 56 183 163 43 /63 115 1/23 139 343 220 13 300 1164 32 4 /64 100 3/164 117 1/44 139 364 207 1/24 282 TRAILING EDGE 36 1/4132 5161 1439 361 1/246 1/2270 INSTANT IL UE 1, Thck 296 1 oTh, 296 2 Thick 550 2, 75/ 556 BASSWOOD45 3/163/1626 3/161/430 3/163/839 3/161/246 3/163/460 1/41442 143649 143460 3/63860 3/61/270 3/63490 1/21/290 1/234100 BUNDLE DEALS 20-116336685 201164361020 203/32 33684 15332 436955 151/6336715 104/6436675 153/16336900 103/16436810 101/4336630 101/4436690 103/8 336650 536439625 51/2336540 51/24361055 103/32448645 51/8448465 5-316 448565 514448625 * NEW * Hundreds new sizes accessories finishing materials Send #10 SASE latest catalog SPRUCE STICKS 36 41 181/81522 181/41824 1/93/82029 316 3/162534 1/4 1/43145 14 3/83650 1/41/24565 3/6 3/64563 3/61/25570 1/2X 1/26060 1/2346868 SPRUCE TRIANGLES 3/8 3/8 1/2 1/2 34 34 1/8 6 1/612 1/412 HARD MAPLE 143/8 36 812 3934 12 34 B 40 45 50 58 59 BIRCH DO WELS36 1809 31611 1414 51625 3532 3PLYBIRCH41 6412630 13212445 11612455 812450 SPLYBINCH 3/2212 1/612 3631612 45l/4X12 013/812 1/2412 41 596 625 625 625 725 900 LITE PLY 41GROOVED LG MOUNTS 13 Inches 1503/83/4/1/8/40 3003/83145/32/40 4751/234l3/16/45 Cost 45 Handling Charge W pay UPS Add $250 COD $300 extra PP APO FPO Statee accept Visa Master Card persosal check, COO 60051 Ia, Te6s US Curr600y Mirmm Wacd Order 51000 V TN 37075 producing some pretcy sporty aero modeling trophies awards engraves em free has club/chapter insignia duplication service chatll produce distinctive prizes con tests fly-ins catalog $2and well worth youre CD looking crophies Jims prices reasonable well flying season beginning across country seems like good time co interrupt readingso can go out fresh air FLY Back atcha next month RC Electrics/Kopski Continued page 43 switches favorites arming switches just arent available current ratings consistent large 20 amps todays mo tors draw would seem Well worry Ive using miniature toggle switches rated between five 10 amps years no problems fact manufacturers know supply systems too Ex amples include Astro DSC five amps Kyosho six amps So low ratings work OK higher currents answer lies partly operative word arming As explained referenced article arming switches like main switches power systems also clude radio-operated power controls like elec tronic switches relays speed controls latter devices operate radio command ultimately control power flow battery motor arming switch simply enables circuit power controls free intended job Thus arming switch first turned radio-operated controls normally still Off no power flows motor through tog gle switch other words arming switches switch cold used activate power flow RC devices Used way tiny light toggle switches take very little electrical abuse contacts simply subjected arcing spark ing would case alone controlled motor power As result quite fail ure-free case despite fact motor current ultimately flows through can exceed ratings factor three five times what about same switches used primary OnIOff control motor power such servo driven An other good question certainly true latter application quite abusive No doubt about have used small toggles way too guess what work pretty good BUT unlike used arming switches have fail direct control appli cation Such failures take form erratic intermittent operation and/or considerable ohmic loss latter always results switches getting quite warm hot occurrences notwithstanding usu ally give good service flights before such symptoms show up can re placed coo great expense course in-flight failure always possibility should pose coo serious problem planes pilots So againnot worry asked about index Electric columns seems reader cuts saves articles say finds difficult find something remembers having seen some time along way have no current index avail able time Ive thinking about de veloping last time column listed index September 85 issue covered writings beginning Septem ber 83 Look update index later year Some reader feedback March 88 column concerning new Astro 02/035 gear drive has come column described new Part No 4046 all-metal gear drive fits ferrite 05 motors well intended As tro cobalts gear drive very similar As tro drives recent years larger cobalt mo tors very rugged should solve problems associated small A-in output shafts used other 05 drives reader has told replacing drive Leisure LT 50 motor Astro part biggest problem encountered doing getting old pinion small gear off motor shaft As suggestion try first covering open ings front end bell tape care fully slit gear between teeth Dremel tool cutoff wheel can done several places desired pinion gear can split off motor shaft nutcracker tool suspect slit gear could also opened up just about kind driving wedge such old sharpened screwdriver perhaps small chisel Whatever sure properly support motor motor shaft place jeopardy gear-splitting necessary gear Another reader question recently received Continued page 133 June 1988 129
Edition: Model Aviation - 1988/06
Page Numbers: 40, 41, 128, 129
SNOWED under Doctor Jim Pepino responsi bleand office full paper latest Care package Scale Plans & Photo Ser vice 3209 Madison Ave Greensboro NC 27403 just arrived large red mailing tube brought door friendly mailman con tained three Doc Jims latest Giant Scale draw ings included deHavilland Chipmunk two cockpit configurations beautiful Fairchild PT-19 including mods fullcanopy version Waco YMF-7 Golden Age biplane three drawing sets bear evidence Jims excellent draftsmanship exhaustive scale re search example always provides accurate-documentation three-views right plans notes degree construction difficulty builder will know what getting before first bit spruce balsa cut Other nice touches include recommenda tions suitable engines tabular indication wood sizes types required complete model Finally Doctor Jim contracts better fi berglass parts manufacturers provide cowl ings wheel pants other difficult-to-build parts designs Man wish time build Wacoits absolutely gorgeous phone has ringing off hook lately Nine long distance calls Out 10 enquiries about suitability particular Giant Scale en gines specific model designs Although drawings scratch-building include engine rec onunendations seem need addi tional assurance particular power plant will adequate Unfortunately bunch misinforma Pat Massey Pampa TX justly proud scratch-built Aeronca KCA Power OS Ge mini 16 Cu twin-cylinder four-stroke Photo Below shows scale details cluding spring-loaded floating gas gauge just ahead windshield rivets addition baf fling false exhaust headers OS closely duplicate full-scale installation Func tional cowl latches allow cowling removed easily engine servicing Photo next page R shows completely detailed cockpit complete dual controls instrument pa nel Seats padded upholstered full-scale ship tion misconception floating around out particular model Lets consider representa about engine use Such confu- tive list sion understandable because host factors go choosing power plant l flying weight 40 Model Aviation Radio Control Giant Scale John de Vries Colonel USAF Ret 4610 Moffat Ln Colorado Springs CO 90915 Don Piatt Pampa TX built fine pair models Rearwin Speedster L Great Planes kit Sig Morrissey Bravo R Rearwin weighs 17 lb uses OS 120 power Its color scheme predominantly red Bravo uses Supertigre 3000 power weighs 19 lb general considering practical rules-ofthumb factors influence engine choice following ways Probably most-used criteria engine se lection projected weight finished mo del Experts have suggested Giant Scale mod els 15- 20-lb range should use smal ler two-cubic-inch gas burners models weighing 20 35 lb engines repre sented Quadra Q-50 suitable birds 35 lb up AMA maximum weight limit talking big Kawasakis Sachs Dolmars other muscular engines rule considering wing area volume seems squares cubes larger powerful engine should isnt strictly true because bigger birds fly wing rather en gine Wing loading may better factor con sider High wing loadings expressed ounces per square foot require powerful hum mersto help keep airspeed up Aerodynamic drag must overcome models power plant Smooth slick models like Lasers Warbirds lot less draggy fully rigged biplanesand can get slightly less noise engine compartment Big engines equal heavy engines Giant comes Out tail-heavy cure may stick heavier engine onto firewall Admittedly may scientific way locate mod els CG properly lot model builders go route lot us figure paid 40 bucks engine servo isnt substitute cubic inches After can always pull throttle back cant array engines available Giant Scale Continued page 128 Hundreds unusual tools borrowed tile Jewelr Gunsmithing Clock Making professional Making trades NOW AVAILABLE TO YOU BY MAIL guaranteed II use coupon sena name anoress $100 MICROMARK 340-531 Snyder Ave Berkeley Heights NJ 07922 ADDRESS L hZIPJ 410246-60 10604160041-60 1960 w140401cobadaOrlOd 410 a4160160011600CAIIOIEWlW0S wiaenoBO&lS54141laWAClS Most versatile mufflers ever offered 0 Designed fit inside cowls wIth limIted space can also used HELICOPTERS BOATS 0 For UPRIGHT INVERTED SIDE mounted engInes 0 Exhaust tubes point almost direction 0 Worm drive clamp universal mounting can bolted directly engine BASIC DIMENSIONS 030411 IjoO flowrl INCLuDEs Exhaust pipe extensions clamps worm drive clamp muffler alignment plate gasket mounting screws U ovo4obte hobby shOp OROEFt DIREcT Eruludote sNpment chects MO Vls Mc coo accepted Ada $250 UPS 5200 coo 6% sales cae resident jI m 164 School St Daly CIty CA 94014 415 756-3400 June 1988 41 over 1000 m1 NEW Catalog FROMI MicroMark Small Tool Specialists Model wing area/wing volume Predictable parasite induced drag Model balance Engine efficiency Engine cost availability Propeller efficiency Flight altitude Cowling Personal brand preference iWO-CYCLE IN-COWL AIRCRAFr MUFFLERS 19-4045-6075-13 engines UPRIGHT e INVERTED ENGINE J-401 19-40 itm JT-401 AS-at 19 JT-901 7513 21 Totes podntto head Eonlrroeotedeo-tglneor o4601l 01011011 boots 41-60410-AC 106041-02 19-AC 1560 41-60441-60106041-60645-60 1460 41-60411-IA 216041-406 11-132160 no10606lfflSbeWdlalFe 43101905 60011- t$l0060160S altitude about 200 ft realized absolutely no control whatsoever model went left-hand spiral dive resulting impact macadam runway drove OS 30s crankshaft Out through rear crankcase cover turned model yellow Cover ite bag balsawood Also GI Joe pilot lost headbut lived fly again Other having stripped gears servos radio functioned flawlessly after crash So theory about loss control partially disconnected receiver battery pack stuffed rearward tempt shift CG time didnt bother tape radio connectors engine vibration took care rest disconnection So never did find out whether rearward CG shift would have improved J-3s spin entries did learn secure connectors tape fu ture models fly alone fly alone number readers sent letters commented Plane bites man story March 1988 column concerned incident modeler struck seriously injured own plane advice also Never fly alone Apparently lot out dont subscribe advice Most seem feel because no flying site wont suffer injury loss model because someone elses mistake Similarly mistake does jeopardize someone elses safety may true being hit model frequent cause injury Feeding fingers through own models prop com mon cause injury Driving car hand easy may impossible other hand being used stop flow blood Flying untested Scale models recent letter Del Rykert Batavia NY expressed con cern about numerous occasions wherein has seen modelers enter Scale contest model hadnt tested airworthiness Del asked opinion prevent such flagrant violation safety Unfortunately didnt have simple solution offer Del thinks Scale modelers reluctant test fly new model prior entering contest cause want save static judging such case suggests solution may reverse current order judging such fly first have static judging last As stated response Del dont have good feel prevalent problem Thats Im mentioning asking input Scale modelers have real safety problem untested models being flown Scale contests what solution MariahlTriebes Continued page 33 ing point may wish adjust bal ance fit own flying style come accustomed Mariah Sailplane likes fly fast smooth Mariah has full aerobatic cap abilities extremely stable aircraft speeds swept wing keeps plane highly stable during slow flight slows down very well landing need spoilers flaps said done impor tant thing have funand some exhilarating slope flying Ive experi enced has little Sailplane Mariah may best Soarer Ive ever flown shes definitely right up first rank Try yourself youre bound agree Radio Technique/Myers Continued page 36 can accurate enough find transmitters outside AMA frequency tolerances comes measuring power levels really isnt good enough installing Gold Silver stickers paragraph 322 AMA Guidelines requires spectrum analyzer used purpose think ICOM good enough reveal illegal crystal swappingand Contest Director really wants know about RC Giant Scale/de Vries Continued page 41 bewildering Some efficient othersthey convert same amount gas glow fuel power per cubic inch Thus some installations may able get away smaller engine just because efficient others its displacement range too hobby shops distributors carry available engines engine choice may depend availability cost factors other considerations proper propeller can make break spe cific engine great prop efficiency viewpoint may turn competent engine raging tiger Flight altitude included list engine choice factors primarily because its BIG amongst us Rocky Mountains Just cause fly altitudes 5000 7000 ft above sea level know going lose 20% engines power before props spun Conversely fly sea level en gine going put out its full power Since concerned scale outlines ten engine choose determined de sire keep within confines cowling best criteria lot us dont like bunch iromnongery disrupting scale lines models Hence inclined choose physically smaller engine might appropriate power-required view point Finally often consideration brand loyalty weve successful product particular manufacturer dined buy another engines Nothing wrong criterionas long favor ite manufacturer produces range power plants Andyou can choose suitable model Engine choice very personal thing can listen pronouncements experts theyre frequently right can follow rec ommendations models designerafter hes flown model specific engine size push comes shove youll have de cide engine use youll have early building sequence Itll take lot thought consideration final note may interest movers shakers AMA clubs IMAA chapters Jim Jennings Jennings Trophy Sales PO Box 1121 Hendersonville 128 Model Aviation ZIVIA Name Street Addreas City StateZip HoWW RNATIONAL INC AbIELWLiW WE ARE SHOOTING DOWN NIGH BALSA PRICES WITH SUPER QUALITYI Satisfaction Guaranteed Direct Only ULU SHUTS 36 41 30 1162 33 3322 40 1/8 243 316248 14 2 58 132337 120337 1163 374931 332k 3445637 18 3547146 3/163628255 1/4 3738561 516385110 3/8 38612471 1/2 3110155 3/4 3165191 1/164587648 3/324 7094 56 1/6 460106 66 9164 93122 75 1/4 4110134 64 3/8 4165225139 1/2 261 MATCHED SHEETS 42 3324100 164106 3164120 144131 3ALU STICKS 3645 1/16 1214 3/32 1410 3/32 3812 332 11216 19 606 16 141116 1/6 361216 1/8 121924 3/163/161116 316 3/61720 315 122230 14 141624 1/4 361926 1/4 1/22130 14 343444 1414055 5/165162126 3/8 382737 3/8 123246 36 3/44255 3/615270 12 1123653 12 344662 1/215678 5/6 584865 34 3/46780 BALSA HOT LINE Cell SOs 7454394 lOem-& pm Central Time LONE STAR MODELS 1623 57th St Lubbock IX 79412 F SAL BA TRIANGLES 36 141/425 3/83630 1/21/235 343445 155 BALM PLANKS 36 1185 12150 13200 14280 1123275 1124360 22225 23325 24435 33495 34668 TAPERED SHEETS 36 1/4265 1/4385 36269 3/6398 1/23120 LONE STAR EPOXY 9,Lit.895 5r,i596 30 ri596 CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa LIGHT 4-6 LB WOOD36 1/323 /203 /163 323 56 183 163 43 /63 115 1/23 139 343 220 13 300 1164 32 4 /64 100 3/164 117 1/44 139 364 207 1/24 282 TRAILING EDGE 36 1/4132 5161 1439 361 1/246 1/2270 INSTANT IL UE 1, Thck 296 1 oTh, 296 2 Thick 550 2, 75/ 556 BASSWOOD45 3/163/1626 3/161/430 3/163/839 3/161/246 3/163/460 1/41442 143649 143460 3/63860 3/61/270 3/63490 1/21/290 1/234100 BUNDLE DEALS 20-116336685 201164361020 203/32 33684 15332 436955 151/6336715 104/6436675 153/16336900 103/16436810 101/4336630 101/4436690 103/8 336650 536439625 51/2336540 51/24361055 103/32448645 51/8448465 5-316 448565 514448625 * NEW * Hundreds new sizes accessories finishing materials Send #10 SASE latest catalog SPRUCE STICKS 36 41 181/81522 181/41824 1/93/82029 316 3/162534 1/4 1/43145 14 3/83650 1/41/24565 3/6 3/64563 3/61/25570 1/2X 1/26060 1/2346868 SPRUCE TRIANGLES 3/8 3/8 1/2 1/2 34 34 1/8 6 1/612 1/412 HARD MAPLE 143/8 36 812 3934 12 34 B 40 45 50 58 59 BIRCH DO WELS36 1809 31611 1414 51625 3532 3PLYBIRCH41 6412630 13212445 11612455 812450 SPLYBINCH 3/2212 1/612 3631612 45l/4X12 013/812 1/2412 41 596 625 625 625 725 900 LITE PLY 41GROOVED LG MOUNTS 13 Inches 1503/83/4/1/8/40 3003/83145/32/40 4751/234l3/16/45 Cost 45 Handling Charge W pay UPS Add $250 COD $300 extra PP APO FPO Statee accept Visa Master Card persosal check, COO 60051 Ia, Te6s US Curr600y Mirmm Wacd Order 51000 V TN 37075 producing some pretcy sporty aero modeling trophies awards engraves em free has club/chapter insignia duplication service chatll produce distinctive prizes con tests fly-ins catalog $2and well worth youre CD looking crophies Jims prices reasonable well flying season beginning across country seems like good time co interrupt readingso can go out fresh air FLY Back atcha next month RC Electrics/Kopski Continued page 43 switches favorites arming switches just arent available current ratings consistent large 20 amps todays mo tors draw would seem Well worry Ive using miniature toggle switches rated between five 10 amps years no problems fact manufacturers know supply systems too Ex amples include Astro DSC five amps Kyosho six amps So low ratings work OK higher currents answer lies partly operative word arming As explained referenced article arming switches like main switches power systems also clude radio-operated power controls like elec tronic switches relays speed controls latter devices operate radio command ultimately control power flow battery motor arming switch simply enables circuit power controls free intended job Thus arming switch first turned radio-operated controls normally still Off no power flows motor through tog gle switch other words arming switches switch cold used activate power flow RC devices Used way tiny light toggle switches take very little electrical abuse contacts simply subjected arcing spark ing would case alone controlled motor power As result quite fail ure-free case despite fact motor current ultimately flows through can exceed ratings factor three five times what about same switches used primary OnIOff control motor power such servo driven An other good question certainly true latter application quite abusive No doubt about have used small toggles way too guess what work pretty good BUT unlike used arming switches have fail direct control appli cation Such failures take form erratic intermittent operation and/or considerable ohmic loss latter always results switches getting quite warm hot occurrences notwithstanding usu ally give good service flights before such symptoms show up can re placed coo great expense course in-flight failure always possibility should pose coo serious problem planes pilots So againnot worry asked about index Electric columns seems reader cuts saves articles say finds difficult find something remembers having seen some time along way have no current index avail able time Ive thinking about de veloping last time column listed index September 85 issue covered writings beginning Septem ber 83 Look update index later year Some reader feedback March 88 column concerning new Astro 02/035 gear drive has come column described new Part No 4046 all-metal gear drive fits ferrite 05 motors well intended As tro cobalts gear drive very similar As tro drives recent years larger cobalt mo tors very rugged should solve problems associated small A-in output shafts used other 05 drives reader has told replacing drive Leisure LT 50 motor Astro part biggest problem encountered doing getting old pinion small gear off motor shaft As suggestion try first covering open ings front end bell tape care fully slit gear between teeth Dremel tool cutoff wheel can done several places desired pinion gear can split off motor shaft nutcracker tool suspect slit gear could also opened up just about kind driving wedge such old sharpened screwdriver perhaps small chisel Whatever sure properly support motor motor shaft place jeopardy gear-splitting necessary gear Another reader question recently received Continued page 133 June 1988 129
Edition: Model Aviation - 1988/06
Page Numbers: 40, 41, 128, 129
SNOWED under Doctor Jim Pepino responsi bleand office full paper latest Care package Scale Plans & Photo Ser vice 3209 Madison Ave Greensboro NC 27403 just arrived large red mailing tube brought door friendly mailman con tained three Doc Jims latest Giant Scale draw ings included deHavilland Chipmunk two cockpit configurations beautiful Fairchild PT-19 including mods fullcanopy version Waco YMF-7 Golden Age biplane three drawing sets bear evidence Jims excellent draftsmanship exhaustive scale re search example always provides accurate-documentation three-views right plans notes degree construction difficulty builder will know what getting before first bit spruce balsa cut Other nice touches include recommenda tions suitable engines tabular indication wood sizes types required complete model Finally Doctor Jim contracts better fi berglass parts manufacturers provide cowl ings wheel pants other difficult-to-build parts designs Man wish time build Wacoits absolutely gorgeous phone has ringing off hook lately Nine long distance calls Out 10 enquiries about suitability particular Giant Scale en gines specific model designs Although drawings scratch-building include engine rec onunendations seem need addi tional assurance particular power plant will adequate Unfortunately bunch misinforma Pat Massey Pampa TX justly proud scratch-built Aeronca KCA Power OS Ge mini 16 Cu twin-cylinder four-stroke Photo Below shows scale details cluding spring-loaded floating gas gauge just ahead windshield rivets addition baf fling false exhaust headers OS closely duplicate full-scale installation Func tional cowl latches allow cowling removed easily engine servicing Photo next page R shows completely detailed cockpit complete dual controls instrument pa nel Seats padded upholstered full-scale ship tion misconception floating around out particular model Lets consider representa about engine use Such confu- tive list sion understandable because host factors go choosing power plant l flying weight 40 Model Aviation Radio Control Giant Scale John de Vries Colonel USAF Ret 4610 Moffat Ln Colorado Springs CO 90915 Don Piatt Pampa TX built fine pair models Rearwin Speedster L Great Planes kit Sig Morrissey Bravo R Rearwin weighs 17 lb uses OS 120 power Its color scheme predominantly red Bravo uses Supertigre 3000 power weighs 19 lb general considering practical rules-ofthumb factors influence engine choice following ways Probably most-used criteria engine se lection projected weight finished mo del Experts have suggested Giant Scale mod els 15- 20-lb range should use smal ler two-cubic-inch gas burners models weighing 20 35 lb engines repre sented Quadra Q-50 suitable birds 35 lb up AMA maximum weight limit talking big Kawasakis Sachs Dolmars other muscular engines rule considering wing area volume seems squares cubes larger powerful engine should isnt strictly true because bigger birds fly wing rather en gine Wing loading may better factor con sider High wing loadings expressed ounces per square foot require powerful hum mersto help keep airspeed up Aerodynamic drag must overcome models power plant Smooth slick models like Lasers Warbirds lot less draggy fully rigged biplanesand can get slightly less noise engine compartment Big engines equal heavy engines Giant comes Out tail-heavy cure may stick heavier engine onto firewall Admittedly may scientific way locate mod els CG properly lot model builders go route lot us figure paid 40 bucks engine servo isnt substitute cubic inches After can always pull throttle back cant array engines available Giant Scale Continued page 128 Hundreds unusual tools borrowed tile Jewelr Gunsmithing Clock Making professional Making trades NOW AVAILABLE TO YOU BY MAIL guaranteed II use coupon sena name anoress $100 MICROMARK 340-531 Snyder Ave Berkeley Heights NJ 07922 ADDRESS L hZIPJ 410246-60 10604160041-60 1960 w140401cobadaOrlOd 410 a4160160011600CAIIOIEWlW0S wiaenoBO&lS54141laWAClS Most versatile mufflers ever offered 0 Designed fit inside cowls wIth limIted space can also used HELICOPTERS BOATS 0 For UPRIGHT INVERTED SIDE mounted engInes 0 Exhaust tubes point almost direction 0 Worm drive clamp universal mounting can bolted directly engine BASIC DIMENSIONS 030411 IjoO flowrl INCLuDEs Exhaust pipe extensions clamps worm drive clamp muffler alignment plate gasket mounting screws U ovo4obte hobby shOp OROEFt DIREcT Eruludote sNpment chects MO Vls Mc coo accepted Ada $250 UPS 5200 coo 6% sales cae resident jI m 164 School St Daly CIty CA 94014 415 756-3400 June 1988 41 over 1000 m1 NEW Catalog FROMI MicroMark Small Tool Specialists Model wing area/wing volume Predictable parasite induced drag Model balance Engine efficiency Engine cost availability Propeller efficiency Flight altitude Cowling Personal brand preference iWO-CYCLE IN-COWL AIRCRAFr MUFFLERS 19-4045-6075-13 engines UPRIGHT e INVERTED ENGINE J-401 19-40 itm JT-401 AS-at 19 JT-901 7513 21 Totes podntto head Eonlrroeotedeo-tglneor o4601l 01011011 boots 41-60410-AC 106041-02 19-AC 1560 41-60441-60106041-60645-60 1460 41-60411-IA 216041-406 11-132160 no10606lfflSbeWdlalFe 43101905 60011- t$l0060160S altitude about 200 ft realized absolutely no control whatsoever model went left-hand spiral dive resulting impact macadam runway drove OS 30s crankshaft Out through rear crankcase cover turned model yellow Cover ite bag balsawood Also GI Joe pilot lost headbut lived fly again Other having stripped gears servos radio functioned flawlessly after crash So theory about loss control partially disconnected receiver battery pack stuffed rearward tempt shift CG time didnt bother tape radio connectors engine vibration took care rest disconnection So never did find out whether rearward CG shift would have improved J-3s spin entries did learn secure connectors tape fu ture models fly alone fly alone number readers sent letters commented Plane bites man story March 1988 column concerned incident modeler struck seriously injured own plane advice also Never fly alone Apparently lot out dont subscribe advice Most seem feel because no flying site wont suffer injury loss model because someone elses mistake Similarly mistake does jeopardize someone elses safety may true being hit model frequent cause injury Feeding fingers through own models prop com mon cause injury Driving car hand easy may impossible other hand being used stop flow blood Flying untested Scale models recent letter Del Rykert Batavia NY expressed con cern about numerous occasions wherein has seen modelers enter Scale contest model hadnt tested airworthiness Del asked opinion prevent such flagrant violation safety Unfortunately didnt have simple solution offer Del thinks Scale modelers reluctant test fly new model prior entering contest cause want save static judging such case suggests solution may reverse current order judging such fly first have static judging last As stated response Del dont have good feel prevalent problem Thats Im mentioning asking input Scale modelers have real safety problem untested models being flown Scale contests what solution MariahlTriebes Continued page 33 ing point may wish adjust bal ance fit own flying style come accustomed Mariah Sailplane likes fly fast smooth Mariah has full aerobatic cap abilities extremely stable aircraft speeds swept wing keeps plane highly stable during slow flight slows down very well landing need spoilers flaps said done impor tant thing have funand some exhilarating slope flying Ive experi enced has little Sailplane Mariah may best Soarer Ive ever flown shes definitely right up first rank Try yourself youre bound agree Radio Technique/Myers Continued page 36 can accurate enough find transmitters outside AMA frequency tolerances comes measuring power levels really isnt good enough installing Gold Silver stickers paragraph 322 AMA Guidelines requires spectrum analyzer used purpose think ICOM good enough reveal illegal crystal swappingand Contest Director really wants know about RC Giant Scale/de Vries Continued page 41 bewildering Some efficient othersthey convert same amount gas glow fuel power per cubic inch Thus some installations may able get away smaller engine just because efficient others its displacement range too hobby shops distributors carry available engines engine choice may depend availability cost factors other considerations proper propeller can make break spe cific engine great prop efficiency viewpoint may turn competent engine raging tiger Flight altitude included list engine choice factors primarily because its BIG amongst us Rocky Mountains Just cause fly altitudes 5000 7000 ft above sea level know going lose 20% engines power before props spun Conversely fly sea level en gine going put out its full power Since concerned scale outlines ten engine choose determined de sire keep within confines cowling best criteria lot us dont like bunch iromnongery disrupting scale lines models Hence inclined choose physically smaller engine might appropriate power-required view point Finally often consideration brand loyalty weve successful product particular manufacturer dined buy another engines Nothing wrong criterionas long favor ite manufacturer produces range power plants Andyou can choose suitable model Engine choice very personal thing can listen pronouncements experts theyre frequently right can follow rec ommendations models designerafter hes flown model specific engine size push comes shove youll have de cide engine use youll have early building sequence Itll take lot thought consideration final note may interest movers shakers AMA clubs IMAA chapters Jim Jennings Jennings Trophy Sales PO Box 1121 Hendersonville 128 Model Aviation ZIVIA Name Street Addreas City StateZip HoWW RNATIONAL INC AbIELWLiW WE ARE SHOOTING DOWN NIGH BALSA PRICES WITH SUPER QUALITYI Satisfaction Guaranteed Direct Only ULU SHUTS 36 41 30 1162 33 3322 40 1/8 243 316248 14 2 58 132337 120337 1163 374931 332k 3445637 18 3547146 3/163628255 1/4 3738561 516385110 3/8 38612471 1/2 3110155 3/4 3165191 1/164587648 3/324 7094 56 1/6 460106 66 9164 93122 75 1/4 4110134 64 3/8 4165225139 1/2 261 MATCHED SHEETS 42 3324100 164106 3164120 144131 3ALU STICKS 3645 1/16 1214 3/32 1410 3/32 3812 332 11216 19 606 16 141116 1/6 361216 1/8 121924 3/163/161116 316 3/61720 315 122230 14 141624 1/4 361926 1/4 1/22130 14 343444 1414055 5/165162126 3/8 382737 3/8 123246 36 3/44255 3/615270 12 1123653 12 344662 1/215678 5/6 584865 34 3/46780 BALSA HOT LINE Cell SOs 7454394 lOem-& pm Central Time LONE STAR MODELS 1623 57th St Lubbock IX 79412 F SAL BA TRIANGLES 36 141/425 3/83630 1/21/235 343445 155 BALM PLANKS 36 1185 12150 13200 14280 1123275 1124360 22225 23325 24435 33495 34668 TAPERED SHEETS 36 1/4265 1/4385 36269 3/6398 1/23120 LONE STAR EPOXY 9,Lit.895 5r,i596 30 ri596 CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa LIGHT 4-6 LB WOOD36 1/323 /203 /163 323 56 183 163 43 /63 115 1/23 139 343 220 13 300 1164 32 4 /64 100 3/164 117 1/44 139 364 207 1/24 282 TRAILING EDGE 36 1/4132 5161 1439 361 1/246 1/2270 INSTANT IL UE 1, Thck 296 1 oTh, 296 2 Thick 550 2, 75/ 556 BASSWOOD45 3/163/1626 3/161/430 3/163/839 3/161/246 3/163/460 1/41442 143649 143460 3/63860 3/61/270 3/63490 1/21/290 1/234100 BUNDLE DEALS 20-116336685 201164361020 203/32 33684 15332 436955 151/6336715 104/6436675 153/16336900 103/16436810 101/4336630 101/4436690 103/8 336650 536439625 51/2336540 51/24361055 103/32448645 51/8448465 5-316 448565 514448625 * NEW * Hundreds new sizes accessories finishing materials Send #10 SASE latest catalog SPRUCE STICKS 36 41 181/81522 181/41824 1/93/82029 316 3/162534 1/4 1/43145 14 3/83650 1/41/24565 3/6 3/64563 3/61/25570 1/2X 1/26060 1/2346868 SPRUCE TRIANGLES 3/8 3/8 1/2 1/2 34 34 1/8 6 1/612 1/412 HARD MAPLE 143/8 36 812 3934 12 34 B 40 45 50 58 59 BIRCH DO WELS36 1809 31611 1414 51625 3532 3PLYBIRCH41 6412630 13212445 11612455 812450 SPLYBINCH 3/2212 1/612 3631612 45l/4X12 013/812 1/2412 41 596 625 625 625 725 900 LITE PLY 41GROOVED LG MOUNTS 13 Inches 1503/83/4/1/8/40 3003/83145/32/40 4751/234l3/16/45 Cost 45 Handling Charge W pay UPS Add $250 COD $300 extra PP APO FPO Statee accept Visa Master Card persosal check, COO 60051 Ia, Te6s US Curr600y Mirmm Wacd Order 51000 V TN 37075 producing some pretcy sporty aero modeling trophies awards engraves em free has club/chapter insignia duplication service chatll produce distinctive prizes con tests fly-ins catalog $2and well worth youre CD looking crophies Jims prices reasonable well flying season beginning across country seems like good time co interrupt readingso can go out fresh air FLY Back atcha next month RC Electrics/Kopski Continued page 43 switches favorites arming switches just arent available current ratings consistent large 20 amps todays mo tors draw would seem Well worry Ive using miniature toggle switches rated between five 10 amps years no problems fact manufacturers know supply systems too Ex amples include Astro DSC five amps Kyosho six amps So low ratings work OK higher currents answer lies partly operative word arming As explained referenced article arming switches like main switches power systems also clude radio-operated power controls like elec tronic switches relays speed controls latter devices operate radio command ultimately control power flow battery motor arming switch simply enables circuit power controls free intended job Thus arming switch first turned radio-operated controls normally still Off no power flows motor through tog gle switch other words arming switches switch cold used activate power flow RC devices Used way tiny light toggle switches take very little electrical abuse contacts simply subjected arcing spark ing would case alone controlled motor power As result quite fail ure-free case despite fact motor current ultimately flows through can exceed ratings factor three five times what about same switches used primary OnIOff control motor power such servo driven An other good question certainly true latter application quite abusive No doubt about have used small toggles way too guess what work pretty good BUT unlike used arming switches have fail direct control appli cation Such failures take form erratic intermittent operation and/or considerable ohmic loss latter always results switches getting quite warm hot occurrences notwithstanding usu ally give good service flights before such symptoms show up can re placed coo great expense course in-flight failure always possibility should pose coo serious problem planes pilots So againnot worry asked about index Electric columns seems reader cuts saves articles say finds difficult find something remembers having seen some time along way have no current index avail able time Ive thinking about de veloping last time column listed index September 85 issue covered writings beginning Septem ber 83 Look update index later year Some reader feedback March 88 column concerning new Astro 02/035 gear drive has come column described new Part No 4046 all-metal gear drive fits ferrite 05 motors well intended As tro cobalts gear drive very similar As tro drives recent years larger cobalt mo tors very rugged should solve problems associated small A-in output shafts used other 05 drives reader has told replacing drive Leisure LT 50 motor Astro part biggest problem encountered doing getting old pinion small gear off motor shaft As suggestion try first covering open ings front end bell tape care fully slit gear between teeth Dremel tool cutoff wheel can done several places desired pinion gear can split off motor shaft nutcracker tool suspect slit gear could also opened up just about kind driving wedge such old sharpened screwdriver perhaps small chisel Whatever sure properly support motor motor shaft place jeopardy gear-splitting necessary gear Another reader question recently received Continued page 133 June 1988 129