At 1981 Nats NASA Special Achievement Award went bird P-39 Airacobra engine mounted behind cockpit water-cooled connected prop through drive shaft CL Sport Scale model indeed special THE FIRST TIME saw P-39 flight must have 1941 near Wright Field sound engine speed clean lines different radial-engined P shooters biplanes common days awestruck have fas cinated its unique design ever since P-39 Americas first-line pur suit planes time Pearl Harbor Decem ber 1941 made its initial flight April 1938 Wright Field time Pearl Harbor attack nearly 600 built Its unique engine location behind cockpit caused some concern first experience showed no hazard crash landing engine located forward cockpit However P-39s spin charac teristics could quite problem proper recovery techniques ignored Airacobra saw combat throughout world particularly Southwest Pacific Mediterranean Russian theaters Because its engine equipped supercharger P-39 performed best below 17000 feet often used lower altitudes ground strafing P-39 production ended August 1944 Bell built 9584 4773 allotted Soviet Union Russian pilots appreciated P-39 its 37mm cannon its ground attack capabilities against German armored forces nwdel Several years ago decided design build Sport Scale model P39 concept simple enough air-cooled engine sticking out breeze up front retracts throttle control Id very good performance lots fun similar model P-5 1 Mustang built Al Rabes plans equipped retracts throttle control Sport Scale came along Mustang started winning first place trophies contests came design time just couldnt see pretty Cobra lines being dirtied up engine sitting up nose decided move engine back cockpit area like real air-cool leaving windows Out around wind screen Full-size drawings started construction chassis wing proceeding almost concurrently drawings P-39 Thafs happened run across article RC magazine some folks experimenting liquidcooled engines flowthrough radiator system Th- U Model sits runway Wright Field original P39 made maiden flight 1938 Enya 45 marine engine Sits amidships scale location drive shaft extends forward prop results getting convinced go liquid-cooled setup P-39 allowing close cockpit windows should As luck would have found Goldberg retracts would just barely fit machine didnt have design build own did Mustang scale P-39 sized 3-in diameter spinner 3-in diameter main gear wheels would proper scale Too times see good looking airplane spoiled wrong size wheels end piece music wire Landing gears should look like landing gears Before commenting construction air frame Id like describe major systems plane leaming experiences during past year Cooling system little apprehensive about everyone said would work Still took lot nerve fire up brand new Enya 45 first time Id run minute two shut off see radiator getting heat went getting braver time As tumed out cooling system thing airplane has given no problems works beautifully However decided take Texas Nats past summer started thinking about 100-degree heat decided add extra cooling capacity extra radiator tank mounted alongside fan radiator area batteries landing gear servo shown drawing sheet No 1 batteries moved back sit top chassis just front former G better balance second radiator tank detailed drawing No 2 Robart pumper has done its job well pumping coolant through system dont know what makes little things work whats inside safe side keep cool possible mounted between cool outlet fan radiator inlet engine cooling jacket use undiluted antifreeze fear diluting water may cause steam problems system 66 Model Aviation / tIEVI - p _____________________________________________________ p--i 7 A___1 SE nt .5J Left right ianaing gear servo batteries exnaust tube tuci tank engine radiators fan Tube ducts exhaust out bottom plane nuuan aueueusrankCase preure move antifreeze radiator engine note wire clamps ail tube connections FULL-SIZE PLANSAVAILABLE . SEE PAGE 140 -a rr C Sn a_ VSRITM arSLaIBQ524L3LDERL& NOSEAAAEEL 4474444 4444499 5 3 2Zt~ 94344454A 19 rCa &aaAaaaAfl99 - OSIELL 3J AGtAUG5OtA 4CAI 343-I-4 CANTAA144 SPORT SCALPI CAL 44443 MAlI BAA4CRCA4AKIAAIIO3I4t 44543 DAAAAJ AMA 43341 COP Drive shaft Now heres funand will benefit experience started using standard boat pans off shelfi 3/16-in dia drive shaft screw-on universal front prop connection Forget started making drive shafts various connection systems failed because setscrews flats drive shaft just wouldnt hold finally made -in drive shaft shown drawings connection rear drive shaft front universal part must keyed shown four big 4-28 setscrews alone wont hold couple flights way its shown drawings works fine has no loosening connection since parts keyed People always asking about vibration long drive shaft no problems Theres no vibration airplane conventional engine/prop connection fact flywheel effect drive shaft seems make things smoother usual Retractable landing gear As mentioned earlier Goldberg retracts used P-39 nose gear strut will have extended length shown drawing No 1 other modifi cations addition extra helper spring nose gear two helper springs outboard main gear Remember have centrifugal force contend Control Line model best way check see have enough strength balance force stand airplane its outboard wing tip will simulate G outward force operate adjust springs until gear works easily landing gear operating servo Power Driver manufactured Wing Manufacturing Co should able order through local hobby shop modified give power travel replacing plastic jack screw longer brass-threaded rod also replaced plastic gears brass ones give higher gear ratio changed May 198267 aSzLThvesAr itt 4995 99544.9. aa T mexone exnauas manvorn ana TUDS macion TO engine wirn silicone sealer keep oil contaminating inside fuselage ran ana raumalura txire ranietor lanhi ian auueu uciure Ijuing LU Inc 1981 Nats Texas AIr passes over corrugated brass surface bottom aft fuselage isnt added permanently until quite late constructionRudder elevator surfaces covered heavy silkspan Engine Elevator pushrod installed adjusted pointand cooling system sit under cockpit belicrank wing powerful motor run 6 volts Operating three landing gears off servo takes pretty powerful servo Another point make gear retracts near scale time instead snapping jerking up down often see models Flight judges should give full points realistically operating retracts Control system look plans see bellcrank located out wing know what youre going sayhes Out mind worry same system has worked per fectly Mustang 11 years works perfectly Cobra too reason location twofold First cant have control lines running through main gear wheel wells interfering things Secondly frees up space inside wing center section landing gear operating mechanisms entire control system shown drawing sheet No 2 looks like Rube Carl Goldberg know works fine allows us following three control lines release parking brake ready takeoff apply brakes taxiing advance retard throttle retract extend landing gear will operate flight controls system really dont need helper get started fly Just start engine let sit idle parking brake set go out pick up control handle apply full up elevator release brake add little power taxi takeoff position Full down elevator applies brake stopping Electrical system dont know people fool around complicated mechanical airoperated retract systems something simple shown drawing sheet No 2 possible key components good powerful servo off-the-shelf stuff supplier such Radio Shack course system wasnt possible until decade ago inexpensive mini diodes became available 68 Model Aviation Forward tuselage ready receive engine cooling system Note ply nose former removable access forward drive shaft bearings Aft fuselage tail ready joining main fuselage Plywood core balsa rib construction light very durable Drive snart assemoly LefttO right universal connection thrust bearing rear bearing block pulley drive radiator fan front bearing prop drive hub setup worked best several tried Drive shaft main front bearing disassembled Two ball bearings used Pins prop drive hub match holes prop spinner backplate allow reverse current bypass limit switches operating landing gear Also note master switch shown circuit absolutely essential prevent accidental retraction landing gear also shut off system may adjusting lever throw landing gear doors etc Please note however must turn want retract gear flight cost dearly 1981 Nats overlooked spite printed check list fly best flight gear down blew potential 20 points off near-90 flight score electrical circuit scheme shows exterior plug-in starting battery However since drawings made have eliminated external starting battery completely Instead just installed extra pencell inside plane turned external switch heats plug continuously during flight gives extra few hundred rpm full throttle no flood-out reiy low idle battery lasts haIfa dozen flights Now have to start turn ignition switch hit starter Construction Well lets face build airplane have half smart half stupid good craftsman lover realism Control Line flying dont meet quali fications go oi next article still go dont have whole lot say about construc tion Cobra because detailed drawings complete could Study drawings theyll answer questions Note fuselage chassis offset almost four degrees right done two very important reasons First provides necessary outward thrust good line tension second makes room exhaust manifold exhaust pipe wing removable two very important reasons First youre going contest cramped four-wheel motorcycles have drive days can put bird inside instead having strap roof second reason removable wing important accessibility Scale model kind have able get operating parts systems repair main tenance really dont want have cut beautiful fuselage wing get faulty servo Thats Ive located landing gear servo other systems top wing center section repairs adjustments necessary just remove two bolts release couple connections voila exposed ready fixed Wing construction style Al Rabe super way build straight wing use couple of-in 0 D aluminum tubes about five feet long set whole thing up wing still jig installed landing gear makes easier check wheel align ment strut length etc found easier build fuselage back former G mate wing point waiting until very last build aft fuselage tail section Youll picking plane up turning over hundreds times during construction have rear half airplane way during have favorite ways construct fuselage Ive seen em allcarved slabs sheet planks fiberglass molded balsa etc baby ran across composite method worked out well First cut 3/32 planking about 5/16 wide went planking away Its hard rough-sanded filled bad places DAP spackling compound cheap available local paint store stuff good because water sol uble can worked smoothed place finger dipped water After glop dries sand everything final shape apply 2oz glass cloth polyester resin After has cured sand smooth Mix up thick batch DAP water paint whole fuselage fill rough areas fiberglass job Give final sanding spray two coats urethane paint Thats Lightweight super strong beautiful finish Flying Cobra Now comes moment truth Youve put time effort building youre ready get air White knuckles shaky knees Non en per speriorum no sweat craft good flier youre ready takeoff release brake feed power slowly until feel resistance retract switch against throttle line Let build up speed half lap gently ease small amount up elevator shell come off ground realistic manner May 198269 Jack tolly wanted mount engine scale positionunder cockpitso designed built radiator system cool water-jacketed Enya 45 marine engine P-39 No wonder took Special Achievement Award 1981 Nats presented bythe National Associ ation Scale Aeromodelers Several different drive shafts tried redesigned too Continued page 132 Rear drive shaft showing universal drive pin ball thrust bearing Nylon rear bearing block takes thrust drive pin would pull out universal joint Front end drive shaft shows main front bearing prop drive hub pins engage prop spinner backplate win-power 2 Blade Tractor 545354Us 6364iSo 747678Us 848688lOs 949697 98104106needs 11411-6118SI 124125126*110 2 Blade PusherAT YOUR DEALER 5% 3 54 63 64 lOs 86 Us 9610-6 *1 3 BladeTractor 53 63 64 Us 3 BladePusher 63 3iade MetallicAluminum Color Tractor 76 78 51 8688 *ia 96 106104 fl Pusher06 *110 - & PARTS CRICKET KIT$19995 wflrwine Eng*27995 w/K & B 35 Eng*29995 *includes heat sink & muffler built-up radios RTF avaIlable prices Call 412-342-574O GRISH LARGE WOOD PROPELLERS HARDWOOD too hard minimizes chance costly plane engine damage True pitch airfoil fully finished balanced ready coating 3/8 BOREALL SIZES IN18 S7 6 B 10 12 PITCH 208 2210 2413 formation national organization Control Line new try national coalition organization will mean sacrificing some speed progress others great deal individual identity groups possibly certain leaders contrast Speed Team Race fraternities have virtually nothing lose participation great deal gain would nice see some type organization moving improve declining Speed fraternity interested send SASE Gazette 707 2nd Street Davis CA 95616 Contest Before ending would like mention Northwest Regionals Eugene OR May29 30 1982 big shoot-out Northwest Mike Hazel CD planning have Speed events year Now chance Speed modelers support event information send SASE Mike Hazel 1040 Windemere Drive NW Salem OR 97304 next two columns will special FAI Speed series will cover both model design engine setup Happy Flying Gene Hempet 301 N Yale Dr Garlana TX 75042 P-39 Airacobra/Stolly Continued page 69 Right after breaking ground push throttle rest wayand gear coming up fighter jock style After initial climb-out pull throttle back three quarters cruise use full power climbing maneuvers makes realistic flight No tricky stuff very stable havent looped yet tells can indeed nice wide realistic loop Mus tang same weight identical areas movements goes loop realistic fashion trying imitate Stunt boys because real airplanes dont way anyhow first flight P-39 left front cowling cockpit section off sure adequate cooling extra nose weight still three-wheel race car took whole lap before built up enough speed get air Nose heavy moved batteries back station G balanced perfectly Because weight nose gear moving rear after retraction its better flier gear up Landings easy about half power As soon main gear touches down nose drops finished flyingbuilt-in nobounce system Thats way its supposed 132 Model Aviation NW aMp GONTIILIII TillS PROFILE0 COMBA PRA T WIDE & NARROW WEDGE 15 -- 6 oz Capacities INIFLOW & STINDD Custom Dliii lisle Ingredients detailed brochure50C stamps/check CAROLINA TAFFINDER 8345 Delhi Road Charleston Hgts SC 29405 45-60 Powered Sport Competition Flying Complete Parts Support HIROBO SCALE HEUCOPTERS 50-60 Powered Tow Cobra Ranger Lama uois ultimate scale helicopters PLAZA HOBBYCRAFT p473 E State Street Sharon PA 16146 fornddo PROPELLERS Made polyester boil color Go GRISH propeller True helical pitch airfoil Sizes pitches styles RIGHT HAND TRACTOR NEW SIZE IN 8 & 10 PITCH 28 516 GRISH~iHN INDIANA 46373 Some philosophy first Control Line plane Jim Walker Fireball 1942 Black market purchase paper route money Sev eral years models later breezed through Air Force Pilot Training much help model flying experiences fact stationed remote far-flung Air Force bases always found fellow pilots model builders Control Line flying nearest thing flying real plane have feel plane hand throttle brakes re tracts heavy Scale plane its same old feeling bringing real bird down final approach landing Im knocking RC much fun Besides get satis faction designing building own bird feel sorry guys other modeling fields miss half fun satisfaction being modeler Recently P-39 took first place Cincin nati OH contest struck certain amount pride judges asked parts plane actually made could truthfully answer Only engine wheels prop spinner sir greatest satis faction modeling came Texas Nats last year P-39 won NASA National Association Scale Aeromodelers Special Achievement Award made worth give credit credit due however would have possible understanding helpful wife pit person Thanks Naomi Documentation intend compete P-39 Airacobra youll need three-view drawings etc called AMA rule book source Historical nation Album published Paul R Matt PO Box 33 Temple City CA 91780 Space Shuttle Il/Hux Continued page 72 shuttle youll find interesting models around friend has described shuttle controlled falling body Thats pretty accurate design resists stalling preferring level sink larger light weight model looks like actually flying rather falling Both smaller will immediately upright themselves attitude flight Enough Rockwells design Since have expressed interest larger shuttle plans 1/48 plans quite similar original 1/72 drawings pay careful attention differences Use JET HAWK F4 PHANTOMFAGLE HUNDERBIRD REVENGEAlL II TLAS BOOTLEGGETO ZLI -5O L LASER 0 KIN pA dYIG OBRA $3P THAWK HArH THUNDERB RD RI EN TI U ATLAS i300TL GOF OP&JOR ZLIN Z OL LASER 20 NTST P- B FLYING TIG P PLANE JAN AAt Local Dealer Send $100 Catalog v i 1 May 1982 133 IN STOCK FOR IMMEDIATE SHIPMENT NewSUPER QUADRA$9995 wth BRISIGHELLA FLYWHEEL 996 QUADRA MARINE engine 495 QUADRA RSPAIR$1000 plot petit KIORITZ engine 244 cc in$19995 Jim Mccc, ERCOUPEPLANS $2395 KIT $22995 Jin Mccc, TOMAHAWKPLANS $2395 KIT $23995 BALSA end BASSWOOD cli niece35% OFF Concept FLEETKIT $17995 FG Cowl $1995 QUADRA fole tenke16 oc $696 32 cc $795 VICKERS LEWIS MACHINE GUN KITS$1496 10 die COVERED WHEELS USA Pop$2596 PLAAISs SUPER STEARMAN Godfrey$2800 STARDUSTER TOO Brieghellc$2996 conic J3 CUB NeIi$2995 VOLKSPLANE Chioken CIterlie$2195 FLY BABY $1896 SES Reocohl$Z495 COCKPIT KITS Tonehcwk F4U-1 Spittre$2195 Eronope $1795 Stearteen $2096 Citebrie $2496 J-3 Cob $1950 ME109 $2150 Fleet $1996 FIBERGLASS ARROW SHAFTS 5/16 032 IgB/$1000 24-Hour Service. Add $250 postage Send Bank Check Money Order JIM MESSERS QUALITY MODEL PRODUCTS 106 Valley View Dr Allegany NY 14706
Edition: Model Aviation - 1982/05
Page Numbers: 65, 66, 67, 68, 69, 132, 133
At 1981 Nats NASA Special Achievement Award went bird P-39 Airacobra engine mounted behind cockpit water-cooled connected prop through drive shaft CL Sport Scale model indeed special THE FIRST TIME saw P-39 flight must have 1941 near Wright Field sound engine speed clean lines different radial-engined P shooters biplanes common days awestruck have fas cinated its unique design ever since P-39 Americas first-line pur suit planes time Pearl Harbor Decem ber 1941 made its initial flight April 1938 Wright Field time Pearl Harbor attack nearly 600 built Its unique engine location behind cockpit caused some concern first experience showed no hazard crash landing engine located forward cockpit However P-39s spin charac teristics could quite problem proper recovery techniques ignored Airacobra saw combat throughout world particularly Southwest Pacific Mediterranean Russian theaters Because its engine equipped supercharger P-39 performed best below 17000 feet often used lower altitudes ground strafing P-39 production ended August 1944 Bell built 9584 4773 allotted Soviet Union Russian pilots appreciated P-39 its 37mm cannon its ground attack capabilities against German armored forces nwdel Several years ago decided design build Sport Scale model P39 concept simple enough air-cooled engine sticking out breeze up front retracts throttle control Id very good performance lots fun similar model P-5 1 Mustang built Al Rabes plans equipped retracts throttle control Sport Scale came along Mustang started winning first place trophies contests came design time just couldnt see pretty Cobra lines being dirtied up engine sitting up nose decided move engine back cockpit area like real air-cool leaving windows Out around wind screen Full-size drawings started construction chassis wing proceeding almost concurrently drawings P-39 Thafs happened run across article RC magazine some folks experimenting liquidcooled engines flowthrough radiator system Th- U Model sits runway Wright Field original P39 made maiden flight 1938 Enya 45 marine engine Sits amidships scale location drive shaft extends forward prop results getting convinced go liquid-cooled setup P-39 allowing close cockpit windows should As luck would have found Goldberg retracts would just barely fit machine didnt have design build own did Mustang scale P-39 sized 3-in diameter spinner 3-in diameter main gear wheels would proper scale Too times see good looking airplane spoiled wrong size wheels end piece music wire Landing gears should look like landing gears Before commenting construction air frame Id like describe major systems plane leaming experiences during past year Cooling system little apprehensive about everyone said would work Still took lot nerve fire up brand new Enya 45 first time Id run minute two shut off see radiator getting heat went getting braver time As tumed out cooling system thing airplane has given no problems works beautifully However decided take Texas Nats past summer started thinking about 100-degree heat decided add extra cooling capacity extra radiator tank mounted alongside fan radiator area batteries landing gear servo shown drawing sheet No 1 batteries moved back sit top chassis just front former G better balance second radiator tank detailed drawing No 2 Robart pumper has done its job well pumping coolant through system dont know what makes little things work whats inside safe side keep cool possible mounted between cool outlet fan radiator inlet engine cooling jacket use undiluted antifreeze fear diluting water may cause steam problems system 66 Model Aviation / tIEVI - p _____________________________________________________ p--i 7 A___1 SE nt .5J Left right ianaing gear servo batteries exnaust tube tuci tank engine radiators fan Tube ducts exhaust out bottom plane nuuan aueueusrankCase preure move antifreeze radiator engine note wire clamps ail tube connections FULL-SIZE PLANSAVAILABLE . SEE PAGE 140 -a rr C Sn a_ VSRITM arSLaIBQ524L3LDERL& NOSEAAAEEL 4474444 4444499 5 3 2Zt~ 94344454A 19 rCa &aaAaaaAfl99 - OSIELL 3J AGtAUG5OtA 4CAI 343-I-4 CANTAA144 SPORT SCALPI CAL 44443 MAlI BAA4CRCA4AKIAAIIO3I4t 44543 DAAAAJ AMA 43341 COP Drive shaft Now heres funand will benefit experience started using standard boat pans off shelfi 3/16-in dia drive shaft screw-on universal front prop connection Forget started making drive shafts various connection systems failed because setscrews flats drive shaft just wouldnt hold finally made -in drive shaft shown drawings connection rear drive shaft front universal part must keyed shown four big 4-28 setscrews alone wont hold couple flights way its shown drawings works fine has no loosening connection since parts keyed People always asking about vibration long drive shaft no problems Theres no vibration airplane conventional engine/prop connection fact flywheel effect drive shaft seems make things smoother usual Retractable landing gear As mentioned earlier Goldberg retracts used P-39 nose gear strut will have extended length shown drawing No 1 other modifi cations addition extra helper spring nose gear two helper springs outboard main gear Remember have centrifugal force contend Control Line model best way check see have enough strength balance force stand airplane its outboard wing tip will simulate G outward force operate adjust springs until gear works easily landing gear operating servo Power Driver manufactured Wing Manufacturing Co should able order through local hobby shop modified give power travel replacing plastic jack screw longer brass-threaded rod also replaced plastic gears brass ones give higher gear ratio changed May 198267 aSzLThvesAr itt 4995 99544.9. aa T mexone exnauas manvorn ana TUDS macion TO engine wirn silicone sealer keep oil contaminating inside fuselage ran ana raumalura txire ranietor lanhi ian auueu uciure Ijuing LU Inc 1981 Nats Texas AIr passes over corrugated brass surface bottom aft fuselage isnt added permanently until quite late constructionRudder elevator surfaces covered heavy silkspan Engine Elevator pushrod installed adjusted pointand cooling system sit under cockpit belicrank wing powerful motor run 6 volts Operating three landing gears off servo takes pretty powerful servo Another point make gear retracts near scale time instead snapping jerking up down often see models Flight judges should give full points realistically operating retracts Control system look plans see bellcrank located out wing know what youre going sayhes Out mind worry same system has worked per fectly Mustang 11 years works perfectly Cobra too reason location twofold First cant have control lines running through main gear wheel wells interfering things Secondly frees up space inside wing center section landing gear operating mechanisms entire control system shown drawing sheet No 2 looks like Rube Carl Goldberg know works fine allows us following three control lines release parking brake ready takeoff apply brakes taxiing advance retard throttle retract extend landing gear will operate flight controls system really dont need helper get started fly Just start engine let sit idle parking brake set go out pick up control handle apply full up elevator release brake add little power taxi takeoff position Full down elevator applies brake stopping Electrical system dont know people fool around complicated mechanical airoperated retract systems something simple shown drawing sheet No 2 possible key components good powerful servo off-the-shelf stuff supplier such Radio Shack course system wasnt possible until decade ago inexpensive mini diodes became available 68 Model Aviation Forward tuselage ready receive engine cooling system Note ply nose former removable access forward drive shaft bearings Aft fuselage tail ready joining main fuselage Plywood core balsa rib construction light very durable Drive snart assemoly LefttO right universal connection thrust bearing rear bearing block pulley drive radiator fan front bearing prop drive hub setup worked best several tried Drive shaft main front bearing disassembled Two ball bearings used Pins prop drive hub match holes prop spinner backplate allow reverse current bypass limit switches operating landing gear Also note master switch shown circuit absolutely essential prevent accidental retraction landing gear also shut off system may adjusting lever throw landing gear doors etc Please note however must turn want retract gear flight cost dearly 1981 Nats overlooked spite printed check list fly best flight gear down blew potential 20 points off near-90 flight score electrical circuit scheme shows exterior plug-in starting battery However since drawings made have eliminated external starting battery completely Instead just installed extra pencell inside plane turned external switch heats plug continuously during flight gives extra few hundred rpm full throttle no flood-out reiy low idle battery lasts haIfa dozen flights Now have to start turn ignition switch hit starter Construction Well lets face build airplane have half smart half stupid good craftsman lover realism Control Line flying dont meet quali fications go oi next article still go dont have whole lot say about construc tion Cobra because detailed drawings complete could Study drawings theyll answer questions Note fuselage chassis offset almost four degrees right done two very important reasons First provides necessary outward thrust good line tension second makes room exhaust manifold exhaust pipe wing removable two very important reasons First youre going contest cramped four-wheel motorcycles have drive days can put bird inside instead having strap roof second reason removable wing important accessibility Scale model kind have able get operating parts systems repair main tenance really dont want have cut beautiful fuselage wing get faulty servo Thats Ive located landing gear servo other systems top wing center section repairs adjustments necessary just remove two bolts release couple connections voila exposed ready fixed Wing construction style Al Rabe super way build straight wing use couple of-in 0 D aluminum tubes about five feet long set whole thing up wing still jig installed landing gear makes easier check wheel align ment strut length etc found easier build fuselage back former G mate wing point waiting until very last build aft fuselage tail section Youll picking plane up turning over hundreds times during construction have rear half airplane way during have favorite ways construct fuselage Ive seen em allcarved slabs sheet planks fiberglass molded balsa etc baby ran across composite method worked out well First cut 3/32 planking about 5/16 wide went planking away Its hard rough-sanded filled bad places DAP spackling compound cheap available local paint store stuff good because water sol uble can worked smoothed place finger dipped water After glop dries sand everything final shape apply 2oz glass cloth polyester resin After has cured sand smooth Mix up thick batch DAP water paint whole fuselage fill rough areas fiberglass job Give final sanding spray two coats urethane paint Thats Lightweight super strong beautiful finish Flying Cobra Now comes moment truth Youve put time effort building youre ready get air White knuckles shaky knees Non en per speriorum no sweat craft good flier youre ready takeoff release brake feed power slowly until feel resistance retract switch against throttle line Let build up speed half lap gently ease small amount up elevator shell come off ground realistic manner May 198269 Jack tolly wanted mount engine scale positionunder cockpitso designed built radiator system cool water-jacketed Enya 45 marine engine P-39 No wonder took Special Achievement Award 1981 Nats presented bythe National Associ ation Scale Aeromodelers Several different drive shafts tried redesigned too Continued page 132 Rear drive shaft showing universal drive pin ball thrust bearing Nylon rear bearing block takes thrust drive pin would pull out universal joint Front end drive shaft shows main front bearing prop drive hub pins engage prop spinner backplate win-power 2 Blade Tractor 545354Us 6364iSo 747678Us 848688lOs 949697 98104106needs 11411-6118SI 124125126*110 2 Blade PusherAT YOUR DEALER 5% 3 54 63 64 lOs 86 Us 9610-6 *1 3 BladeTractor 53 63 64 Us 3 BladePusher 63 3iade MetallicAluminum Color Tractor 76 78 51 8688 *ia 96 106104 fl Pusher06 *110 - & PARTS CRICKET KIT$19995 wflrwine Eng*27995 w/K & B 35 Eng*29995 *includes heat sink & muffler built-up radios RTF avaIlable prices Call 412-342-574O GRISH LARGE WOOD PROPELLERS HARDWOOD too hard minimizes chance costly plane engine damage True pitch airfoil fully finished balanced ready coating 3/8 BOREALL SIZES IN18 S7 6 B 10 12 PITCH 208 2210 2413 formation national organization Control Line new try national coalition organization will mean sacrificing some speed progress others great deal individual identity groups possibly certain leaders contrast Speed Team Race fraternities have virtually nothing lose participation great deal gain would nice see some type organization moving improve declining Speed fraternity interested send SASE Gazette 707 2nd Street Davis CA 95616 Contest Before ending would like mention Northwest Regionals Eugene OR May29 30 1982 big shoot-out Northwest Mike Hazel CD planning have Speed events year Now chance Speed modelers support event information send SASE Mike Hazel 1040 Windemere Drive NW Salem OR 97304 next two columns will special FAI Speed series will cover both model design engine setup Happy Flying Gene Hempet 301 N Yale Dr Garlana TX 75042 P-39 Airacobra/Stolly Continued page 69 Right after breaking ground push throttle rest wayand gear coming up fighter jock style After initial climb-out pull throttle back three quarters cruise use full power climbing maneuvers makes realistic flight No tricky stuff very stable havent looped yet tells can indeed nice wide realistic loop Mus tang same weight identical areas movements goes loop realistic fashion trying imitate Stunt boys because real airplanes dont way anyhow first flight P-39 left front cowling cockpit section off sure adequate cooling extra nose weight still three-wheel race car took whole lap before built up enough speed get air Nose heavy moved batteries back station G balanced perfectly Because weight nose gear moving rear after retraction its better flier gear up Landings easy about half power As soon main gear touches down nose drops finished flyingbuilt-in nobounce system Thats way its supposed 132 Model Aviation NW aMp GONTIILIII TillS PROFILE0 COMBA PRA T WIDE & NARROW WEDGE 15 -- 6 oz Capacities INIFLOW & STINDD Custom Dliii lisle Ingredients detailed brochure50C stamps/check CAROLINA TAFFINDER 8345 Delhi Road Charleston Hgts SC 29405 45-60 Powered Sport Competition Flying Complete Parts Support HIROBO SCALE HEUCOPTERS 50-60 Powered Tow Cobra Ranger Lama uois ultimate scale helicopters PLAZA HOBBYCRAFT p473 E State Street Sharon PA 16146 fornddo PROPELLERS Made polyester boil color Go GRISH propeller True helical pitch airfoil Sizes pitches styles RIGHT HAND TRACTOR NEW SIZE IN 8 & 10 PITCH 28 516 GRISH~iHN INDIANA 46373 Some philosophy first Control Line plane Jim Walker Fireball 1942 Black market purchase paper route money Sev eral years models later breezed through Air Force Pilot Training much help model flying experiences fact stationed remote far-flung Air Force bases always found fellow pilots model builders Control Line flying nearest thing flying real plane have feel plane hand throttle brakes re tracts heavy Scale plane its same old feeling bringing real bird down final approach landing Im knocking RC much fun Besides get satis faction designing building own bird feel sorry guys other modeling fields miss half fun satisfaction being modeler Recently P-39 took first place Cincin nati OH contest struck certain amount pride judges asked parts plane actually made could truthfully answer Only engine wheels prop spinner sir greatest satis faction modeling came Texas Nats last year P-39 won NASA National Association Scale Aeromodelers Special Achievement Award made worth give credit credit due however would have possible understanding helpful wife pit person Thanks Naomi Documentation intend compete P-39 Airacobra youll need three-view drawings etc called AMA rule book source Historical nation Album published Paul R Matt PO Box 33 Temple City CA 91780 Space Shuttle Il/Hux Continued page 72 shuttle youll find interesting models around friend has described shuttle controlled falling body Thats pretty accurate design resists stalling preferring level sink larger light weight model looks like actually flying rather falling Both smaller will immediately upright themselves attitude flight Enough Rockwells design Since have expressed interest larger shuttle plans 1/48 plans quite similar original 1/72 drawings pay careful attention differences Use JET HAWK F4 PHANTOMFAGLE HUNDERBIRD REVENGEAlL II TLAS BOOTLEGGETO ZLI -5O L LASER 0 KIN pA dYIG OBRA $3P THAWK HArH THUNDERB RD RI EN TI U ATLAS i300TL GOF OP&JOR ZLIN Z OL LASER 20 NTST P- B FLYING TIG P PLANE JAN AAt Local Dealer Send $100 Catalog v i 1 May 1982 133 IN STOCK FOR IMMEDIATE SHIPMENT NewSUPER QUADRA$9995 wth BRISIGHELLA FLYWHEEL 996 QUADRA MARINE engine 495 QUADRA RSPAIR$1000 plot petit KIORITZ engine 244 cc in$19995 Jim Mccc, ERCOUPEPLANS $2395 KIT $22995 Jin Mccc, TOMAHAWKPLANS $2395 KIT $23995 BALSA end BASSWOOD cli niece35% OFF Concept FLEETKIT $17995 FG Cowl $1995 QUADRA fole tenke16 oc $696 32 cc $795 VICKERS LEWIS MACHINE GUN KITS$1496 10 die COVERED WHEELS USA Pop$2596 PLAAISs SUPER STEARMAN Godfrey$2800 STARDUSTER TOO Brieghellc$2996 conic J3 CUB NeIi$2995 VOLKSPLANE Chioken CIterlie$2195 FLY BABY $1896 SES Reocohl$Z495 COCKPIT KITS Tonehcwk F4U-1 Spittre$2195 Eronope $1795 Stearteen $2096 Citebrie $2496 J-3 Cob $1950 ME109 $2150 Fleet $1996 FIBERGLASS ARROW SHAFTS 5/16 032 IgB/$1000 24-Hour Service. Add $250 postage Send Bank Check Money Order JIM MESSERS QUALITY MODEL PRODUCTS 106 Valley View Dr Allegany NY 14706
Edition: Model Aviation - 1982/05
Page Numbers: 65, 66, 67, 68, 69, 132, 133
At 1981 Nats NASA Special Achievement Award went bird P-39 Airacobra engine mounted behind cockpit water-cooled connected prop through drive shaft CL Sport Scale model indeed special THE FIRST TIME saw P-39 flight must have 1941 near Wright Field sound engine speed clean lines different radial-engined P shooters biplanes common days awestruck have fas cinated its unique design ever since P-39 Americas first-line pur suit planes time Pearl Harbor Decem ber 1941 made its initial flight April 1938 Wright Field time Pearl Harbor attack nearly 600 built Its unique engine location behind cockpit caused some concern first experience showed no hazard crash landing engine located forward cockpit However P-39s spin charac teristics could quite problem proper recovery techniques ignored Airacobra saw combat throughout world particularly Southwest Pacific Mediterranean Russian theaters Because its engine equipped supercharger P-39 performed best below 17000 feet often used lower altitudes ground strafing P-39 production ended August 1944 Bell built 9584 4773 allotted Soviet Union Russian pilots appreciated P-39 its 37mm cannon its ground attack capabilities against German armored forces nwdel Several years ago decided design build Sport Scale model P39 concept simple enough air-cooled engine sticking out breeze up front retracts throttle control Id very good performance lots fun similar model P-5 1 Mustang built Al Rabes plans equipped retracts throttle control Sport Scale came along Mustang started winning first place trophies contests came design time just couldnt see pretty Cobra lines being dirtied up engine sitting up nose decided move engine back cockpit area like real air-cool leaving windows Out around wind screen Full-size drawings started construction chassis wing proceeding almost concurrently drawings P-39 Thafs happened run across article RC magazine some folks experimenting liquidcooled engines flowthrough radiator system Th- U Model sits runway Wright Field original P39 made maiden flight 1938 Enya 45 marine engine Sits amidships scale location drive shaft extends forward prop results getting convinced go liquid-cooled setup P-39 allowing close cockpit windows should As luck would have found Goldberg retracts would just barely fit machine didnt have design build own did Mustang scale P-39 sized 3-in diameter spinner 3-in diameter main gear wheels would proper scale Too times see good looking airplane spoiled wrong size wheels end piece music wire Landing gears should look like landing gears Before commenting construction air frame Id like describe major systems plane leaming experiences during past year Cooling system little apprehensive about everyone said would work Still took lot nerve fire up brand new Enya 45 first time Id run minute two shut off see radiator getting heat went getting braver time As tumed out cooling system thing airplane has given no problems works beautifully However decided take Texas Nats past summer started thinking about 100-degree heat decided add extra cooling capacity extra radiator tank mounted alongside fan radiator area batteries landing gear servo shown drawing sheet No 1 batteries moved back sit top chassis just front former G better balance second radiator tank detailed drawing No 2 Robart pumper has done its job well pumping coolant through system dont know what makes little things work whats inside safe side keep cool possible mounted between cool outlet fan radiator inlet engine cooling jacket use undiluted antifreeze fear diluting water may cause steam problems system 66 Model Aviation / tIEVI - p _____________________________________________________ p--i 7 A___1 SE nt .5J Left right ianaing gear servo batteries exnaust tube tuci tank engine radiators fan Tube ducts exhaust out bottom plane nuuan aueueusrankCase preure move antifreeze radiator engine note wire clamps ail tube connections FULL-SIZE PLANSAVAILABLE . SEE PAGE 140 -a rr C Sn a_ VSRITM arSLaIBQ524L3LDERL& NOSEAAAEEL 4474444 4444499 5 3 2Zt~ 94344454A 19 rCa &aaAaaaAfl99 - OSIELL 3J AGtAUG5OtA 4CAI 343-I-4 CANTAA144 SPORT SCALPI CAL 44443 MAlI BAA4CRCA4AKIAAIIO3I4t 44543 DAAAAJ AMA 43341 COP Drive shaft Now heres funand will benefit experience started using standard boat pans off shelfi 3/16-in dia drive shaft screw-on universal front prop connection Forget started making drive shafts various connection systems failed because setscrews flats drive shaft just wouldnt hold finally made -in drive shaft shown drawings connection rear drive shaft front universal part must keyed shown four big 4-28 setscrews alone wont hold couple flights way its shown drawings works fine has no loosening connection since parts keyed People always asking about vibration long drive shaft no problems Theres no vibration airplane conventional engine/prop connection fact flywheel effect drive shaft seems make things smoother usual Retractable landing gear As mentioned earlier Goldberg retracts used P-39 nose gear strut will have extended length shown drawing No 1 other modifi cations addition extra helper spring nose gear two helper springs outboard main gear Remember have centrifugal force contend Control Line model best way check see have enough strength balance force stand airplane its outboard wing tip will simulate G outward force operate adjust springs until gear works easily landing gear operating servo Power Driver manufactured Wing Manufacturing Co should able order through local hobby shop modified give power travel replacing plastic jack screw longer brass-threaded rod also replaced plastic gears brass ones give higher gear ratio changed May 198267 aSzLThvesAr itt 4995 99544.9. aa T mexone exnauas manvorn ana TUDS macion TO engine wirn silicone sealer keep oil contaminating inside fuselage ran ana raumalura txire ranietor lanhi ian auueu uciure Ijuing LU Inc 1981 Nats Texas AIr passes over corrugated brass surface bottom aft fuselage isnt added permanently until quite late constructionRudder elevator surfaces covered heavy silkspan Engine Elevator pushrod installed adjusted pointand cooling system sit under cockpit belicrank wing powerful motor run 6 volts Operating three landing gears off servo takes pretty powerful servo Another point make gear retracts near scale time instead snapping jerking up down often see models Flight judges should give full points realistically operating retracts Control system look plans see bellcrank located out wing know what youre going sayhes Out mind worry same system has worked per fectly Mustang 11 years works perfectly Cobra too reason location twofold First cant have control lines running through main gear wheel wells interfering things Secondly frees up space inside wing center section landing gear operating mechanisms entire control system shown drawing sheet No 2 looks like Rube Carl Goldberg know works fine allows us following three control lines release parking brake ready takeoff apply brakes taxiing advance retard throttle retract extend landing gear will operate flight controls system really dont need helper get started fly Just start engine let sit idle parking brake set go out pick up control handle apply full up elevator release brake add little power taxi takeoff position Full down elevator applies brake stopping Electrical system dont know people fool around complicated mechanical airoperated retract systems something simple shown drawing sheet No 2 possible key components good powerful servo off-the-shelf stuff supplier such Radio Shack course system wasnt possible until decade ago inexpensive mini diodes became available 68 Model Aviation Forward tuselage ready receive engine cooling system Note ply nose former removable access forward drive shaft bearings Aft fuselage tail ready joining main fuselage Plywood core balsa rib construction light very durable Drive snart assemoly LefttO right universal connection thrust bearing rear bearing block pulley drive radiator fan front bearing prop drive hub setup worked best several tried Drive shaft main front bearing disassembled Two ball bearings used Pins prop drive hub match holes prop spinner backplate allow reverse current bypass limit switches operating landing gear Also note master switch shown circuit absolutely essential prevent accidental retraction landing gear also shut off system may adjusting lever throw landing gear doors etc Please note however must turn want retract gear flight cost dearly 1981 Nats overlooked spite printed check list fly best flight gear down blew potential 20 points off near-90 flight score electrical circuit scheme shows exterior plug-in starting battery However since drawings made have eliminated external starting battery completely Instead just installed extra pencell inside plane turned external switch heats plug continuously during flight gives extra few hundred rpm full throttle no flood-out reiy low idle battery lasts haIfa dozen flights Now have to start turn ignition switch hit starter Construction Well lets face build airplane have half smart half stupid good craftsman lover realism Control Line flying dont meet quali fications go oi next article still go dont have whole lot say about construc tion Cobra because detailed drawings complete could Study drawings theyll answer questions Note fuselage chassis offset almost four degrees right done two very important reasons First provides necessary outward thrust good line tension second makes room exhaust manifold exhaust pipe wing removable two very important reasons First youre going contest cramped four-wheel motorcycles have drive days can put bird inside instead having strap roof second reason removable wing important accessibility Scale model kind have able get operating parts systems repair main tenance really dont want have cut beautiful fuselage wing get faulty servo Thats Ive located landing gear servo other systems top wing center section repairs adjustments necessary just remove two bolts release couple connections voila exposed ready fixed Wing construction style Al Rabe super way build straight wing use couple of-in 0 D aluminum tubes about five feet long set whole thing up wing still jig installed landing gear makes easier check wheel align ment strut length etc found easier build fuselage back former G mate wing point waiting until very last build aft fuselage tail section Youll picking plane up turning over hundreds times during construction have rear half airplane way during have favorite ways construct fuselage Ive seen em allcarved slabs sheet planks fiberglass molded balsa etc baby ran across composite method worked out well First cut 3/32 planking about 5/16 wide went planking away Its hard rough-sanded filled bad places DAP spackling compound cheap available local paint store stuff good because water sol uble can worked smoothed place finger dipped water After glop dries sand everything final shape apply 2oz glass cloth polyester resin After has cured sand smooth Mix up thick batch DAP water paint whole fuselage fill rough areas fiberglass job Give final sanding spray two coats urethane paint Thats Lightweight super strong beautiful finish Flying Cobra Now comes moment truth Youve put time effort building youre ready get air White knuckles shaky knees Non en per speriorum no sweat craft good flier youre ready takeoff release brake feed power slowly until feel resistance retract switch against throttle line Let build up speed half lap gently ease small amount up elevator shell come off ground realistic manner May 198269 Jack tolly wanted mount engine scale positionunder cockpitso designed built radiator system cool water-jacketed Enya 45 marine engine P-39 No wonder took Special Achievement Award 1981 Nats presented bythe National Associ ation Scale Aeromodelers Several different drive shafts tried redesigned too Continued page 132 Rear drive shaft showing universal drive pin ball thrust bearing Nylon rear bearing block takes thrust drive pin would pull out universal joint Front end drive shaft shows main front bearing prop drive hub pins engage prop spinner backplate win-power 2 Blade Tractor 545354Us 6364iSo 747678Us 848688lOs 949697 98104106needs 11411-6118SI 124125126*110 2 Blade PusherAT YOUR DEALER 5% 3 54 63 64 lOs 86 Us 9610-6 *1 3 BladeTractor 53 63 64 Us 3 BladePusher 63 3iade MetallicAluminum Color Tractor 76 78 51 8688 *ia 96 106104 fl Pusher06 *110 - & PARTS CRICKET KIT$19995 wflrwine Eng*27995 w/K & B 35 Eng*29995 *includes heat sink & muffler built-up radios RTF avaIlable prices Call 412-342-574O GRISH LARGE WOOD PROPELLERS HARDWOOD too hard minimizes chance costly plane engine damage True pitch airfoil fully finished balanced ready coating 3/8 BOREALL SIZES IN18 S7 6 B 10 12 PITCH 208 2210 2413 formation national organization Control Line new try national coalition organization will mean sacrificing some speed progress others great deal individual identity groups possibly certain leaders contrast Speed Team Race fraternities have virtually nothing lose participation great deal gain would nice see some type organization moving improve declining Speed fraternity interested send SASE Gazette 707 2nd Street Davis CA 95616 Contest Before ending would like mention Northwest Regionals Eugene OR May29 30 1982 big shoot-out Northwest Mike Hazel CD planning have Speed events year Now chance Speed modelers support event information send SASE Mike Hazel 1040 Windemere Drive NW Salem OR 97304 next two columns will special FAI Speed series will cover both model design engine setup Happy Flying Gene Hempet 301 N Yale Dr Garlana TX 75042 P-39 Airacobra/Stolly Continued page 69 Right after breaking ground push throttle rest wayand gear coming up fighter jock style After initial climb-out pull throttle back three quarters cruise use full power climbing maneuvers makes realistic flight No tricky stuff very stable havent looped yet tells can indeed nice wide realistic loop Mus tang same weight identical areas movements goes loop realistic fashion trying imitate Stunt boys because real airplanes dont way anyhow first flight P-39 left front cowling cockpit section off sure adequate cooling extra nose weight still three-wheel race car took whole lap before built up enough speed get air Nose heavy moved batteries back station G balanced perfectly Because weight nose gear moving rear after retraction its better flier gear up Landings easy about half power As soon main gear touches down nose drops finished flyingbuilt-in nobounce system Thats way its supposed 132 Model Aviation NW aMp GONTIILIII TillS PROFILE0 COMBA PRA T WIDE & NARROW WEDGE 15 -- 6 oz Capacities INIFLOW & STINDD Custom Dliii lisle Ingredients detailed brochure50C stamps/check CAROLINA TAFFINDER 8345 Delhi Road Charleston Hgts SC 29405 45-60 Powered Sport Competition Flying Complete Parts Support HIROBO SCALE HEUCOPTERS 50-60 Powered Tow Cobra Ranger Lama uois ultimate scale helicopters PLAZA HOBBYCRAFT p473 E State Street Sharon PA 16146 fornddo PROPELLERS Made polyester boil color Go GRISH propeller True helical pitch airfoil Sizes pitches styles RIGHT HAND TRACTOR NEW SIZE IN 8 & 10 PITCH 28 516 GRISH~iHN INDIANA 46373 Some philosophy first Control Line plane Jim Walker Fireball 1942 Black market purchase paper route money Sev eral years models later breezed through Air Force Pilot Training much help model flying experiences fact stationed remote far-flung Air Force bases always found fellow pilots model builders Control Line flying nearest thing flying real plane have feel plane hand throttle brakes re tracts heavy Scale plane its same old feeling bringing real bird down final approach landing Im knocking RC much fun Besides get satis faction designing building own bird feel sorry guys other modeling fields miss half fun satisfaction being modeler Recently P-39 took first place Cincin nati OH contest struck certain amount pride judges asked parts plane actually made could truthfully answer Only engine wheels prop spinner sir greatest satis faction modeling came Texas Nats last year P-39 won NASA National Association Scale Aeromodelers Special Achievement Award made worth give credit credit due however would have possible understanding helpful wife pit person Thanks Naomi Documentation intend compete P-39 Airacobra youll need three-view drawings etc called AMA rule book source Historical nation Album published Paul R Matt PO Box 33 Temple City CA 91780 Space Shuttle Il/Hux Continued page 72 shuttle youll find interesting models around friend has described shuttle controlled falling body Thats pretty accurate design resists stalling preferring level sink larger light weight model looks like actually flying rather falling Both smaller will immediately upright themselves attitude flight Enough Rockwells design Since have expressed interest larger shuttle plans 1/48 plans quite similar original 1/72 drawings pay careful attention differences Use JET HAWK F4 PHANTOMFAGLE HUNDERBIRD REVENGEAlL II TLAS BOOTLEGGETO ZLI -5O L LASER 0 KIN pA dYIG OBRA $3P THAWK HArH THUNDERB RD RI EN TI U ATLAS i300TL GOF OP&JOR ZLIN Z OL LASER 20 NTST P- B FLYING TIG P PLANE JAN AAt Local Dealer Send $100 Catalog v i 1 May 1982 133 IN STOCK FOR IMMEDIATE SHIPMENT NewSUPER QUADRA$9995 wth BRISIGHELLA FLYWHEEL 996 QUADRA MARINE engine 495 QUADRA RSPAIR$1000 plot petit KIORITZ engine 244 cc in$19995 Jim Mccc, ERCOUPEPLANS $2395 KIT $22995 Jin Mccc, TOMAHAWKPLANS $2395 KIT $23995 BALSA end BASSWOOD cli niece35% OFF Concept FLEETKIT $17995 FG Cowl $1995 QUADRA fole tenke16 oc $696 32 cc $795 VICKERS LEWIS MACHINE GUN KITS$1496 10 die COVERED WHEELS USA Pop$2596 PLAAISs SUPER STEARMAN Godfrey$2800 STARDUSTER TOO Brieghellc$2996 conic J3 CUB NeIi$2995 VOLKSPLANE Chioken CIterlie$2195 FLY BABY $1896 SES Reocohl$Z495 COCKPIT KITS Tonehcwk F4U-1 Spittre$2195 Eronope $1795 Stearteen $2096 Citebrie $2496 J-3 Cob $1950 ME109 $2150 Fleet $1996 FIBERGLASS ARROW SHAFTS 5/16 032 IgB/$1000 24-Hour Service. Add $250 postage Send Bank Check Money Order JIM MESSERS QUALITY MODEL PRODUCTS 106 Valley View Dr Allegany NY 14706
Edition: Model Aviation - 1982/05
Page Numbers: 65, 66, 67, 68, 69, 132, 133
At 1981 Nats NASA Special Achievement Award went bird P-39 Airacobra engine mounted behind cockpit water-cooled connected prop through drive shaft CL Sport Scale model indeed special THE FIRST TIME saw P-39 flight must have 1941 near Wright Field sound engine speed clean lines different radial-engined P shooters biplanes common days awestruck have fas cinated its unique design ever since P-39 Americas first-line pur suit planes time Pearl Harbor Decem ber 1941 made its initial flight April 1938 Wright Field time Pearl Harbor attack nearly 600 built Its unique engine location behind cockpit caused some concern first experience showed no hazard crash landing engine located forward cockpit However P-39s spin charac teristics could quite problem proper recovery techniques ignored Airacobra saw combat throughout world particularly Southwest Pacific Mediterranean Russian theaters Because its engine equipped supercharger P-39 performed best below 17000 feet often used lower altitudes ground strafing P-39 production ended August 1944 Bell built 9584 4773 allotted Soviet Union Russian pilots appreciated P-39 its 37mm cannon its ground attack capabilities against German armored forces nwdel Several years ago decided design build Sport Scale model P39 concept simple enough air-cooled engine sticking out breeze up front retracts throttle control Id very good performance lots fun similar model P-5 1 Mustang built Al Rabes plans equipped retracts throttle control Sport Scale came along Mustang started winning first place trophies contests came design time just couldnt see pretty Cobra lines being dirtied up engine sitting up nose decided move engine back cockpit area like real air-cool leaving windows Out around wind screen Full-size drawings started construction chassis wing proceeding almost concurrently drawings P-39 Thafs happened run across article RC magazine some folks experimenting liquidcooled engines flowthrough radiator system Th- U Model sits runway Wright Field original P39 made maiden flight 1938 Enya 45 marine engine Sits amidships scale location drive shaft extends forward prop results getting convinced go liquid-cooled setup P-39 allowing close cockpit windows should As luck would have found Goldberg retracts would just barely fit machine didnt have design build own did Mustang scale P-39 sized 3-in diameter spinner 3-in diameter main gear wheels would proper scale Too times see good looking airplane spoiled wrong size wheels end piece music wire Landing gears should look like landing gears Before commenting construction air frame Id like describe major systems plane leaming experiences during past year Cooling system little apprehensive about everyone said would work Still took lot nerve fire up brand new Enya 45 first time Id run minute two shut off see radiator getting heat went getting braver time As tumed out cooling system thing airplane has given no problems works beautifully However decided take Texas Nats past summer started thinking about 100-degree heat decided add extra cooling capacity extra radiator tank mounted alongside fan radiator area batteries landing gear servo shown drawing sheet No 1 batteries moved back sit top chassis just front former G better balance second radiator tank detailed drawing No 2 Robart pumper has done its job well pumping coolant through system dont know what makes little things work whats inside safe side keep cool possible mounted between cool outlet fan radiator inlet engine cooling jacket use undiluted antifreeze fear diluting water may cause steam problems system 66 Model Aviation / tIEVI - p _____________________________________________________ p--i 7 A___1 SE nt .5J Left right ianaing gear servo batteries exnaust tube tuci tank engine radiators fan Tube ducts exhaust out bottom plane nuuan aueueusrankCase preure move antifreeze radiator engine note wire clamps ail tube connections FULL-SIZE PLANSAVAILABLE . SEE PAGE 140 -a rr C Sn a_ VSRITM arSLaIBQ524L3LDERL& NOSEAAAEEL 4474444 4444499 5 3 2Zt~ 94344454A 19 rCa &aaAaaaAfl99 - OSIELL 3J AGtAUG5OtA 4CAI 343-I-4 CANTAA144 SPORT SCALPI CAL 44443 MAlI BAA4CRCA4AKIAAIIO3I4t 44543 DAAAAJ AMA 43341 COP Drive shaft Now heres funand will benefit experience started using standard boat pans off shelfi 3/16-in dia drive shaft screw-on universal front prop connection Forget started making drive shafts various connection systems failed because setscrews flats drive shaft just wouldnt hold finally made -in drive shaft shown drawings connection rear drive shaft front universal part must keyed shown four big 4-28 setscrews alone wont hold couple flights way its shown drawings works fine has no loosening connection since parts keyed People always asking about vibration long drive shaft no problems Theres no vibration airplane conventional engine/prop connection fact flywheel effect drive shaft seems make things smoother usual Retractable landing gear As mentioned earlier Goldberg retracts used P-39 nose gear strut will have extended length shown drawing No 1 other modifi cations addition extra helper spring nose gear two helper springs outboard main gear Remember have centrifugal force contend Control Line model best way check see have enough strength balance force stand airplane its outboard wing tip will simulate G outward force operate adjust springs until gear works easily landing gear operating servo Power Driver manufactured Wing Manufacturing Co should able order through local hobby shop modified give power travel replacing plastic jack screw longer brass-threaded rod also replaced plastic gears brass ones give higher gear ratio changed May 198267 aSzLThvesAr itt 4995 99544.9. aa T mexone exnauas manvorn ana TUDS macion TO engine wirn silicone sealer keep oil contaminating inside fuselage ran ana raumalura txire ranietor lanhi ian auueu uciure Ijuing LU Inc 1981 Nats Texas AIr passes over corrugated brass surface bottom aft fuselage isnt added permanently until quite late constructionRudder elevator surfaces covered heavy silkspan Engine Elevator pushrod installed adjusted pointand cooling system sit under cockpit belicrank wing powerful motor run 6 volts Operating three landing gears off servo takes pretty powerful servo Another point make gear retracts near scale time instead snapping jerking up down often see models Flight judges should give full points realistically operating retracts Control system look plans see bellcrank located out wing know what youre going sayhes Out mind worry same system has worked per fectly Mustang 11 years works perfectly Cobra too reason location twofold First cant have control lines running through main gear wheel wells interfering things Secondly frees up space inside wing center section landing gear operating mechanisms entire control system shown drawing sheet No 2 looks like Rube Carl Goldberg know works fine allows us following three control lines release parking brake ready takeoff apply brakes taxiing advance retard throttle retract extend landing gear will operate flight controls system really dont need helper get started fly Just start engine let sit idle parking brake set go out pick up control handle apply full up elevator release brake add little power taxi takeoff position Full down elevator applies brake stopping Electrical system dont know people fool around complicated mechanical airoperated retract systems something simple shown drawing sheet No 2 possible key components good powerful servo off-the-shelf stuff supplier such Radio Shack course system wasnt possible until decade ago inexpensive mini diodes became available 68 Model Aviation Forward tuselage ready receive engine cooling system Note ply nose former removable access forward drive shaft bearings Aft fuselage tail ready joining main fuselage Plywood core balsa rib construction light very durable Drive snart assemoly LefttO right universal connection thrust bearing rear bearing block pulley drive radiator fan front bearing prop drive hub setup worked best several tried Drive shaft main front bearing disassembled Two ball bearings used Pins prop drive hub match holes prop spinner backplate allow reverse current bypass limit switches operating landing gear Also note master switch shown circuit absolutely essential prevent accidental retraction landing gear also shut off system may adjusting lever throw landing gear doors etc Please note however must turn want retract gear flight cost dearly 1981 Nats overlooked spite printed check list fly best flight gear down blew potential 20 points off near-90 flight score electrical circuit scheme shows exterior plug-in starting battery However since drawings made have eliminated external starting battery completely Instead just installed extra pencell inside plane turned external switch heats plug continuously during flight gives extra few hundred rpm full throttle no flood-out reiy low idle battery lasts haIfa dozen flights Now have to start turn ignition switch hit starter Construction Well lets face build airplane have half smart half stupid good craftsman lover realism Control Line flying dont meet quali fications go oi next article still go dont have whole lot say about construc tion Cobra because detailed drawings complete could Study drawings theyll answer questions Note fuselage chassis offset almost four degrees right done two very important reasons First provides necessary outward thrust good line tension second makes room exhaust manifold exhaust pipe wing removable two very important reasons First youre going contest cramped four-wheel motorcycles have drive days can put bird inside instead having strap roof second reason removable wing important accessibility Scale model kind have able get operating parts systems repair main tenance really dont want have cut beautiful fuselage wing get faulty servo Thats Ive located landing gear servo other systems top wing center section repairs adjustments necessary just remove two bolts release couple connections voila exposed ready fixed Wing construction style Al Rabe super way build straight wing use couple of-in 0 D aluminum tubes about five feet long set whole thing up wing still jig installed landing gear makes easier check wheel align ment strut length etc found easier build fuselage back former G mate wing point waiting until very last build aft fuselage tail section Youll picking plane up turning over hundreds times during construction have rear half airplane way during have favorite ways construct fuselage Ive seen em allcarved slabs sheet planks fiberglass molded balsa etc baby ran across composite method worked out well First cut 3/32 planking about 5/16 wide went planking away Its hard rough-sanded filled bad places DAP spackling compound cheap available local paint store stuff good because water sol uble can worked smoothed place finger dipped water After glop dries sand everything final shape apply 2oz glass cloth polyester resin After has cured sand smooth Mix up thick batch DAP water paint whole fuselage fill rough areas fiberglass job Give final sanding spray two coats urethane paint Thats Lightweight super strong beautiful finish Flying Cobra Now comes moment truth Youve put time effort building youre ready get air White knuckles shaky knees Non en per speriorum no sweat craft good flier youre ready takeoff release brake feed power slowly until feel resistance retract switch against throttle line Let build up speed half lap gently ease small amount up elevator shell come off ground realistic manner May 198269 Jack tolly wanted mount engine scale positionunder cockpitso designed built radiator system cool water-jacketed Enya 45 marine engine P-39 No wonder took Special Achievement Award 1981 Nats presented bythe National Associ ation Scale Aeromodelers Several different drive shafts tried redesigned too Continued page 132 Rear drive shaft showing universal drive pin ball thrust bearing Nylon rear bearing block takes thrust drive pin would pull out universal joint Front end drive shaft shows main front bearing prop drive hub pins engage prop spinner backplate win-power 2 Blade Tractor 545354Us 6364iSo 747678Us 848688lOs 949697 98104106needs 11411-6118SI 124125126*110 2 Blade PusherAT YOUR DEALER 5% 3 54 63 64 lOs 86 Us 9610-6 *1 3 BladeTractor 53 63 64 Us 3 BladePusher 63 3iade MetallicAluminum Color Tractor 76 78 51 8688 *ia 96 106104 fl Pusher06 *110 - & PARTS CRICKET KIT$19995 wflrwine Eng*27995 w/K & B 35 Eng*29995 *includes heat sink & muffler built-up radios RTF avaIlable prices Call 412-342-574O GRISH LARGE WOOD PROPELLERS HARDWOOD too hard minimizes chance costly plane engine damage True pitch airfoil fully finished balanced ready coating 3/8 BOREALL SIZES IN18 S7 6 B 10 12 PITCH 208 2210 2413 formation national organization Control Line new try national coalition organization will mean sacrificing some speed progress others great deal individual identity groups possibly certain leaders contrast Speed Team Race fraternities have virtually nothing lose participation great deal gain would nice see some type organization moving improve declining Speed fraternity interested send SASE Gazette 707 2nd Street Davis CA 95616 Contest Before ending would like mention Northwest Regionals Eugene OR May29 30 1982 big shoot-out Northwest Mike Hazel CD planning have Speed events year Now chance Speed modelers support event information send SASE Mike Hazel 1040 Windemere Drive NW Salem OR 97304 next two columns will special FAI Speed series will cover both model design engine setup Happy Flying Gene Hempet 301 N Yale Dr Garlana TX 75042 P-39 Airacobra/Stolly Continued page 69 Right after breaking ground push throttle rest wayand gear coming up fighter jock style After initial climb-out pull throttle back three quarters cruise use full power climbing maneuvers makes realistic flight No tricky stuff very stable havent looped yet tells can indeed nice wide realistic loop Mus tang same weight identical areas movements goes loop realistic fashion trying imitate Stunt boys because real airplanes dont way anyhow first flight P-39 left front cowling cockpit section off sure adequate cooling extra nose weight still three-wheel race car took whole lap before built up enough speed get air Nose heavy moved batteries back station G balanced perfectly Because weight nose gear moving rear after retraction its better flier gear up Landings easy about half power As soon main gear touches down nose drops finished flyingbuilt-in nobounce system Thats way its supposed 132 Model Aviation NW aMp GONTIILIII TillS PROFILE0 COMBA PRA T WIDE & NARROW WEDGE 15 -- 6 oz Capacities INIFLOW & STINDD Custom Dliii lisle Ingredients detailed brochure50C stamps/check CAROLINA TAFFINDER 8345 Delhi Road Charleston Hgts SC 29405 45-60 Powered Sport Competition Flying Complete Parts Support HIROBO SCALE HEUCOPTERS 50-60 Powered Tow Cobra Ranger Lama uois ultimate scale helicopters PLAZA HOBBYCRAFT p473 E State Street Sharon PA 16146 fornddo PROPELLERS Made polyester boil color Go GRISH propeller True helical pitch airfoil Sizes pitches styles RIGHT HAND TRACTOR NEW SIZE IN 8 & 10 PITCH 28 516 GRISH~iHN INDIANA 46373 Some philosophy first Control Line plane Jim Walker Fireball 1942 Black market purchase paper route money Sev eral years models later breezed through Air Force Pilot Training much help model flying experiences fact stationed remote far-flung Air Force bases always found fellow pilots model builders Control Line flying nearest thing flying real plane have feel plane hand throttle brakes re tracts heavy Scale plane its same old feeling bringing real bird down final approach landing Im knocking RC much fun Besides get satis faction designing building own bird feel sorry guys other modeling fields miss half fun satisfaction being modeler Recently P-39 took first place Cincin nati OH contest struck certain amount pride judges asked parts plane actually made could truthfully answer Only engine wheels prop spinner sir greatest satis faction modeling came Texas Nats last year P-39 won NASA National Association Scale Aeromodelers Special Achievement Award made worth give credit credit due however would have possible understanding helpful wife pit person Thanks Naomi Documentation intend compete P-39 Airacobra youll need three-view drawings etc called AMA rule book source Historical nation Album published Paul R Matt PO Box 33 Temple City CA 91780 Space Shuttle Il/Hux Continued page 72 shuttle youll find interesting models around friend has described shuttle controlled falling body Thats pretty accurate design resists stalling preferring level sink larger light weight model looks like actually flying rather falling Both smaller will immediately upright themselves attitude flight Enough Rockwells design Since have expressed interest larger shuttle plans 1/48 plans quite similar original 1/72 drawings pay careful attention differences Use JET HAWK F4 PHANTOMFAGLE HUNDERBIRD REVENGEAlL II TLAS BOOTLEGGETO ZLI -5O L LASER 0 KIN pA dYIG OBRA $3P THAWK HArH THUNDERB RD RI EN TI U ATLAS i300TL GOF OP&JOR ZLIN Z OL LASER 20 NTST P- B FLYING TIG P PLANE JAN AAt Local Dealer Send $100 Catalog v i 1 May 1982 133 IN STOCK FOR IMMEDIATE SHIPMENT NewSUPER QUADRA$9995 wth BRISIGHELLA FLYWHEEL 996 QUADRA MARINE engine 495 QUADRA RSPAIR$1000 plot petit KIORITZ engine 244 cc in$19995 Jim Mccc, ERCOUPEPLANS $2395 KIT $22995 Jin Mccc, TOMAHAWKPLANS $2395 KIT $23995 BALSA end BASSWOOD cli niece35% OFF Concept FLEETKIT $17995 FG Cowl $1995 QUADRA fole tenke16 oc $696 32 cc $795 VICKERS LEWIS MACHINE GUN KITS$1496 10 die COVERED WHEELS USA Pop$2596 PLAAISs SUPER STEARMAN Godfrey$2800 STARDUSTER TOO Brieghellc$2996 conic J3 CUB NeIi$2995 VOLKSPLANE Chioken CIterlie$2195 FLY BABY $1896 SES Reocohl$Z495 COCKPIT KITS Tonehcwk F4U-1 Spittre$2195 Eronope $1795 Stearteen $2096 Citebrie $2496 J-3 Cob $1950 ME109 $2150 Fleet $1996 FIBERGLASS ARROW SHAFTS 5/16 032 IgB/$1000 24-Hour Service. Add $250 postage Send Bank Check Money Order JIM MESSERS QUALITY MODEL PRODUCTS 106 Valley View Dr Allegany NY 14706
Edition: Model Aviation - 1982/05
Page Numbers: 65, 66, 67, 68, 69, 132, 133
At 1981 Nats NASA Special Achievement Award went bird P-39 Airacobra engine mounted behind cockpit water-cooled connected prop through drive shaft CL Sport Scale model indeed special THE FIRST TIME saw P-39 flight must have 1941 near Wright Field sound engine speed clean lines different radial-engined P shooters biplanes common days awestruck have fas cinated its unique design ever since P-39 Americas first-line pur suit planes time Pearl Harbor Decem ber 1941 made its initial flight April 1938 Wright Field time Pearl Harbor attack nearly 600 built Its unique engine location behind cockpit caused some concern first experience showed no hazard crash landing engine located forward cockpit However P-39s spin charac teristics could quite problem proper recovery techniques ignored Airacobra saw combat throughout world particularly Southwest Pacific Mediterranean Russian theaters Because its engine equipped supercharger P-39 performed best below 17000 feet often used lower altitudes ground strafing P-39 production ended August 1944 Bell built 9584 4773 allotted Soviet Union Russian pilots appreciated P-39 its 37mm cannon its ground attack capabilities against German armored forces nwdel Several years ago decided design build Sport Scale model P39 concept simple enough air-cooled engine sticking out breeze up front retracts throttle control Id very good performance lots fun similar model P-5 1 Mustang built Al Rabes plans equipped retracts throttle control Sport Scale came along Mustang started winning first place trophies contests came design time just couldnt see pretty Cobra lines being dirtied up engine sitting up nose decided move engine back cockpit area like real air-cool leaving windows Out around wind screen Full-size drawings started construction chassis wing proceeding almost concurrently drawings P-39 Thafs happened run across article RC magazine some folks experimenting liquidcooled engines flowthrough radiator system Th- U Model sits runway Wright Field original P39 made maiden flight 1938 Enya 45 marine engine Sits amidships scale location drive shaft extends forward prop results getting convinced go liquid-cooled setup P-39 allowing close cockpit windows should As luck would have found Goldberg retracts would just barely fit machine didnt have design build own did Mustang scale P-39 sized 3-in diameter spinner 3-in diameter main gear wheels would proper scale Too times see good looking airplane spoiled wrong size wheels end piece music wire Landing gears should look like landing gears Before commenting construction air frame Id like describe major systems plane leaming experiences during past year Cooling system little apprehensive about everyone said would work Still took lot nerve fire up brand new Enya 45 first time Id run minute two shut off see radiator getting heat went getting braver time As tumed out cooling system thing airplane has given no problems works beautifully However decided take Texas Nats past summer started thinking about 100-degree heat decided add extra cooling capacity extra radiator tank mounted alongside fan radiator area batteries landing gear servo shown drawing sheet No 1 batteries moved back sit top chassis just front former G better balance second radiator tank detailed drawing No 2 Robart pumper has done its job well pumping coolant through system dont know what makes little things work whats inside safe side keep cool possible mounted between cool outlet fan radiator inlet engine cooling jacket use undiluted antifreeze fear diluting water may cause steam problems system 66 Model Aviation / tIEVI - p _____________________________________________________ p--i 7 A___1 SE nt .5J Left right ianaing gear servo batteries exnaust tube tuci tank engine radiators fan Tube ducts exhaust out bottom plane nuuan aueueusrankCase preure move antifreeze radiator engine note wire clamps ail tube connections FULL-SIZE PLANSAVAILABLE . SEE PAGE 140 -a rr C Sn a_ VSRITM arSLaIBQ524L3LDERL& NOSEAAAEEL 4474444 4444499 5 3 2Zt~ 94344454A 19 rCa &aaAaaaAfl99 - OSIELL 3J AGtAUG5OtA 4CAI 343-I-4 CANTAA144 SPORT SCALPI CAL 44443 MAlI BAA4CRCA4AKIAAIIO3I4t 44543 DAAAAJ AMA 43341 COP Drive shaft Now heres funand will benefit experience started using standard boat pans off shelfi 3/16-in dia drive shaft screw-on universal front prop connection Forget started making drive shafts various connection systems failed because setscrews flats drive shaft just wouldnt hold finally made -in drive shaft shown drawings connection rear drive shaft front universal part must keyed shown four big 4-28 setscrews alone wont hold couple flights way its shown drawings works fine has no loosening connection since parts keyed People always asking about vibration long drive shaft no problems Theres no vibration airplane conventional engine/prop connection fact flywheel effect drive shaft seems make things smoother usual Retractable landing gear As mentioned earlier Goldberg retracts used P-39 nose gear strut will have extended length shown drawing No 1 other modifi cations addition extra helper spring nose gear two helper springs outboard main gear Remember have centrifugal force contend Control Line model best way check see have enough strength balance force stand airplane its outboard wing tip will simulate G outward force operate adjust springs until gear works easily landing gear operating servo Power Driver manufactured Wing Manufacturing Co should able order through local hobby shop modified give power travel replacing plastic jack screw longer brass-threaded rod also replaced plastic gears brass ones give higher gear ratio changed May 198267 aSzLThvesAr itt 4995 99544.9. aa T mexone exnauas manvorn ana TUDS macion TO engine wirn silicone sealer keep oil contaminating inside fuselage ran ana raumalura txire ranietor lanhi ian auueu uciure Ijuing LU Inc 1981 Nats Texas AIr passes over corrugated brass surface bottom aft fuselage isnt added permanently until quite late constructionRudder elevator surfaces covered heavy silkspan Engine Elevator pushrod installed adjusted pointand cooling system sit under cockpit belicrank wing powerful motor run 6 volts Operating three landing gears off servo takes pretty powerful servo Another point make gear retracts near scale time instead snapping jerking up down often see models Flight judges should give full points realistically operating retracts Control system look plans see bellcrank located out wing know what youre going sayhes Out mind worry same system has worked per fectly Mustang 11 years works perfectly Cobra too reason location twofold First cant have control lines running through main gear wheel wells interfering things Secondly frees up space inside wing center section landing gear operating mechanisms entire control system shown drawing sheet No 2 looks like Rube Carl Goldberg know works fine allows us following three control lines release parking brake ready takeoff apply brakes taxiing advance retard throttle retract extend landing gear will operate flight controls system really dont need helper get started fly Just start engine let sit idle parking brake set go out pick up control handle apply full up elevator release brake add little power taxi takeoff position Full down elevator applies brake stopping Electrical system dont know people fool around complicated mechanical airoperated retract systems something simple shown drawing sheet No 2 possible key components good powerful servo off-the-shelf stuff supplier such Radio Shack course system wasnt possible until decade ago inexpensive mini diodes became available 68 Model Aviation Forward tuselage ready receive engine cooling system Note ply nose former removable access forward drive shaft bearings Aft fuselage tail ready joining main fuselage Plywood core balsa rib construction light very durable Drive snart assemoly LefttO right universal connection thrust bearing rear bearing block pulley drive radiator fan front bearing prop drive hub setup worked best several tried Drive shaft main front bearing disassembled Two ball bearings used Pins prop drive hub match holes prop spinner backplate allow reverse current bypass limit switches operating landing gear Also note master switch shown circuit absolutely essential prevent accidental retraction landing gear also shut off system may adjusting lever throw landing gear doors etc Please note however must turn want retract gear flight cost dearly 1981 Nats overlooked spite printed check list fly best flight gear down blew potential 20 points off near-90 flight score electrical circuit scheme shows exterior plug-in starting battery However since drawings made have eliminated external starting battery completely Instead just installed extra pencell inside plane turned external switch heats plug continuously during flight gives extra few hundred rpm full throttle no flood-out reiy low idle battery lasts haIfa dozen flights Now have to start turn ignition switch hit starter Construction Well lets face build airplane have half smart half stupid good craftsman lover realism Control Line flying dont meet quali fications go oi next article still go dont have whole lot say about construc tion Cobra because detailed drawings complete could Study drawings theyll answer questions Note fuselage chassis offset almost four degrees right done two very important reasons First provides necessary outward thrust good line tension second makes room exhaust manifold exhaust pipe wing removable two very important reasons First youre going contest cramped four-wheel motorcycles have drive days can put bird inside instead having strap roof second reason removable wing important accessibility Scale model kind have able get operating parts systems repair main tenance really dont want have cut beautiful fuselage wing get faulty servo Thats Ive located landing gear servo other systems top wing center section repairs adjustments necessary just remove two bolts release couple connections voila exposed ready fixed Wing construction style Al Rabe super way build straight wing use couple of-in 0 D aluminum tubes about five feet long set whole thing up wing still jig installed landing gear makes easier check wheel align ment strut length etc found easier build fuselage back former G mate wing point waiting until very last build aft fuselage tail section Youll picking plane up turning over hundreds times during construction have rear half airplane way during have favorite ways construct fuselage Ive seen em allcarved slabs sheet planks fiberglass molded balsa etc baby ran across composite method worked out well First cut 3/32 planking about 5/16 wide went planking away Its hard rough-sanded filled bad places DAP spackling compound cheap available local paint store stuff good because water sol uble can worked smoothed place finger dipped water After glop dries sand everything final shape apply 2oz glass cloth polyester resin After has cured sand smooth Mix up thick batch DAP water paint whole fuselage fill rough areas fiberglass job Give final sanding spray two coats urethane paint Thats Lightweight super strong beautiful finish Flying Cobra Now comes moment truth Youve put time effort building youre ready get air White knuckles shaky knees Non en per speriorum no sweat craft good flier youre ready takeoff release brake feed power slowly until feel resistance retract switch against throttle line Let build up speed half lap gently ease small amount up elevator shell come off ground realistic manner May 198269 Jack tolly wanted mount engine scale positionunder cockpitso designed built radiator system cool water-jacketed Enya 45 marine engine P-39 No wonder took Special Achievement Award 1981 Nats presented bythe National Associ ation Scale Aeromodelers Several different drive shafts tried redesigned too Continued page 132 Rear drive shaft showing universal drive pin ball thrust bearing Nylon rear bearing block takes thrust drive pin would pull out universal joint Front end drive shaft shows main front bearing prop drive hub pins engage prop spinner backplate win-power 2 Blade Tractor 545354Us 6364iSo 747678Us 848688lOs 949697 98104106needs 11411-6118SI 124125126*110 2 Blade PusherAT YOUR DEALER 5% 3 54 63 64 lOs 86 Us 9610-6 *1 3 BladeTractor 53 63 64 Us 3 BladePusher 63 3iade MetallicAluminum Color Tractor 76 78 51 8688 *ia 96 106104 fl Pusher06 *110 - & PARTS CRICKET KIT$19995 wflrwine Eng*27995 w/K & B 35 Eng*29995 *includes heat sink & muffler built-up radios RTF avaIlable prices Call 412-342-574O GRISH LARGE WOOD PROPELLERS HARDWOOD too hard minimizes chance costly plane engine damage True pitch airfoil fully finished balanced ready coating 3/8 BOREALL SIZES IN18 S7 6 B 10 12 PITCH 208 2210 2413 formation national organization Control Line new try national coalition organization will mean sacrificing some speed progress others great deal individual identity groups possibly certain leaders contrast Speed Team Race fraternities have virtually nothing lose participation great deal gain would nice see some type organization moving improve declining Speed fraternity interested send SASE Gazette 707 2nd Street Davis CA 95616 Contest Before ending would like mention Northwest Regionals Eugene OR May29 30 1982 big shoot-out Northwest Mike Hazel CD planning have Speed events year Now chance Speed modelers support event information send SASE Mike Hazel 1040 Windemere Drive NW Salem OR 97304 next two columns will special FAI Speed series will cover both model design engine setup Happy Flying Gene Hempet 301 N Yale Dr Garlana TX 75042 P-39 Airacobra/Stolly Continued page 69 Right after breaking ground push throttle rest wayand gear coming up fighter jock style After initial climb-out pull throttle back three quarters cruise use full power climbing maneuvers makes realistic flight No tricky stuff very stable havent looped yet tells can indeed nice wide realistic loop Mus tang same weight identical areas movements goes loop realistic fashion trying imitate Stunt boys because real airplanes dont way anyhow first flight P-39 left front cowling cockpit section off sure adequate cooling extra nose weight still three-wheel race car took whole lap before built up enough speed get air Nose heavy moved batteries back station G balanced perfectly Because weight nose gear moving rear after retraction its better flier gear up Landings easy about half power As soon main gear touches down nose drops finished flyingbuilt-in nobounce system Thats way its supposed 132 Model Aviation NW aMp GONTIILIII TillS PROFILE0 COMBA PRA T WIDE & NARROW WEDGE 15 -- 6 oz Capacities INIFLOW & STINDD Custom Dliii lisle Ingredients detailed brochure50C stamps/check CAROLINA TAFFINDER 8345 Delhi Road Charleston Hgts SC 29405 45-60 Powered Sport Competition Flying Complete Parts Support HIROBO SCALE HEUCOPTERS 50-60 Powered Tow Cobra Ranger Lama uois ultimate scale helicopters PLAZA HOBBYCRAFT p473 E State Street Sharon PA 16146 fornddo PROPELLERS Made polyester boil color Go GRISH propeller True helical pitch airfoil Sizes pitches styles RIGHT HAND TRACTOR NEW SIZE IN 8 & 10 PITCH 28 516 GRISH~iHN INDIANA 46373 Some philosophy first Control Line plane Jim Walker Fireball 1942 Black market purchase paper route money Sev eral years models later breezed through Air Force Pilot Training much help model flying experiences fact stationed remote far-flung Air Force bases always found fellow pilots model builders Control Line flying nearest thing flying real plane have feel plane hand throttle brakes re tracts heavy Scale plane its same old feeling bringing real bird down final approach landing Im knocking RC much fun Besides get satis faction designing building own bird feel sorry guys other modeling fields miss half fun satisfaction being modeler Recently P-39 took first place Cincin nati OH contest struck certain amount pride judges asked parts plane actually made could truthfully answer Only engine wheels prop spinner sir greatest satis faction modeling came Texas Nats last year P-39 won NASA National Association Scale Aeromodelers Special Achievement Award made worth give credit credit due however would have possible understanding helpful wife pit person Thanks Naomi Documentation intend compete P-39 Airacobra youll need three-view drawings etc called AMA rule book source Historical nation Album published Paul R Matt PO Box 33 Temple City CA 91780 Space Shuttle Il/Hux Continued page 72 shuttle youll find interesting models around friend has described shuttle controlled falling body Thats pretty accurate design resists stalling preferring level sink larger light weight model looks like actually flying rather falling Both smaller will immediately upright themselves attitude flight Enough Rockwells design Since have expressed interest larger shuttle plans 1/48 plans quite similar original 1/72 drawings pay careful attention differences Use JET HAWK F4 PHANTOMFAGLE HUNDERBIRD REVENGEAlL II TLAS BOOTLEGGETO ZLI -5O L LASER 0 KIN pA dYIG OBRA $3P THAWK HArH THUNDERB RD RI EN TI U ATLAS i300TL GOF OP&JOR ZLIN Z OL LASER 20 NTST P- B FLYING TIG P PLANE JAN AAt Local Dealer Send $100 Catalog v i 1 May 1982 133 IN STOCK FOR IMMEDIATE SHIPMENT NewSUPER QUADRA$9995 wth BRISIGHELLA FLYWHEEL 996 QUADRA MARINE engine 495 QUADRA RSPAIR$1000 plot petit KIORITZ engine 244 cc in$19995 Jim Mccc, ERCOUPEPLANS $2395 KIT $22995 Jin Mccc, TOMAHAWKPLANS $2395 KIT $23995 BALSA end BASSWOOD cli niece35% OFF Concept FLEETKIT $17995 FG Cowl $1995 QUADRA fole tenke16 oc $696 32 cc $795 VICKERS LEWIS MACHINE GUN KITS$1496 10 die COVERED WHEELS USA Pop$2596 PLAAISs SUPER STEARMAN Godfrey$2800 STARDUSTER TOO Brieghellc$2996 conic J3 CUB NeIi$2995 VOLKSPLANE Chioken CIterlie$2195 FLY BABY $1896 SES Reocohl$Z495 COCKPIT KITS Tonehcwk F4U-1 Spittre$2195 Eronope $1795 Stearteen $2096 Citebrie $2496 J-3 Cob $1950 ME109 $2150 Fleet $1996 FIBERGLASS ARROW SHAFTS 5/16 032 IgB/$1000 24-Hour Service. Add $250 postage Send Bank Check Money Order JIM MESSERS QUALITY MODEL PRODUCTS 106 Valley View Dr Allegany NY 14706
Edition: Model Aviation - 1982/05
Page Numbers: 65, 66, 67, 68, 69, 132, 133
At 1981 Nats NASA Special Achievement Award went bird P-39 Airacobra engine mounted behind cockpit water-cooled connected prop through drive shaft CL Sport Scale model indeed special THE FIRST TIME saw P-39 flight must have 1941 near Wright Field sound engine speed clean lines different radial-engined P shooters biplanes common days awestruck have fas cinated its unique design ever since P-39 Americas first-line pur suit planes time Pearl Harbor Decem ber 1941 made its initial flight April 1938 Wright Field time Pearl Harbor attack nearly 600 built Its unique engine location behind cockpit caused some concern first experience showed no hazard crash landing engine located forward cockpit However P-39s spin charac teristics could quite problem proper recovery techniques ignored Airacobra saw combat throughout world particularly Southwest Pacific Mediterranean Russian theaters Because its engine equipped supercharger P-39 performed best below 17000 feet often used lower altitudes ground strafing P-39 production ended August 1944 Bell built 9584 4773 allotted Soviet Union Russian pilots appreciated P-39 its 37mm cannon its ground attack capabilities against German armored forces nwdel Several years ago decided design build Sport Scale model P39 concept simple enough air-cooled engine sticking out breeze up front retracts throttle control Id very good performance lots fun similar model P-5 1 Mustang built Al Rabes plans equipped retracts throttle control Sport Scale came along Mustang started winning first place trophies contests came design time just couldnt see pretty Cobra lines being dirtied up engine sitting up nose decided move engine back cockpit area like real air-cool leaving windows Out around wind screen Full-size drawings started construction chassis wing proceeding almost concurrently drawings P-39 Thafs happened run across article RC magazine some folks experimenting liquidcooled engines flowthrough radiator system Th- U Model sits runway Wright Field original P39 made maiden flight 1938 Enya 45 marine engine Sits amidships scale location drive shaft extends forward prop results getting convinced go liquid-cooled setup P-39 allowing close cockpit windows should As luck would have found Goldberg retracts would just barely fit machine didnt have design build own did Mustang scale P-39 sized 3-in diameter spinner 3-in diameter main gear wheels would proper scale Too times see good looking airplane spoiled wrong size wheels end piece music wire Landing gears should look like landing gears Before commenting construction air frame Id like describe major systems plane leaming experiences during past year Cooling system little apprehensive about everyone said would work Still took lot nerve fire up brand new Enya 45 first time Id run minute two shut off see radiator getting heat went getting braver time As tumed out cooling system thing airplane has given no problems works beautifully However decided take Texas Nats past summer started thinking about 100-degree heat decided add extra cooling capacity extra radiator tank mounted alongside fan radiator area batteries landing gear servo shown drawing sheet No 1 batteries moved back sit top chassis just front former G better balance second radiator tank detailed drawing No 2 Robart pumper has done its job well pumping coolant through system dont know what makes little things work whats inside safe side keep cool possible mounted between cool outlet fan radiator inlet engine cooling jacket use undiluted antifreeze fear diluting water may cause steam problems system 66 Model Aviation / tIEVI - p _____________________________________________________ p--i 7 A___1 SE nt .5J Left right ianaing gear servo batteries exnaust tube tuci tank engine radiators fan Tube ducts exhaust out bottom plane nuuan aueueusrankCase preure move antifreeze radiator engine note wire clamps ail tube connections FULL-SIZE PLANSAVAILABLE . SEE PAGE 140 -a rr C Sn a_ VSRITM arSLaIBQ524L3LDERL& NOSEAAAEEL 4474444 4444499 5 3 2Zt~ 94344454A 19 rCa &aaAaaaAfl99 - OSIELL 3J AGtAUG5OtA 4CAI 343-I-4 CANTAA144 SPORT SCALPI CAL 44443 MAlI BAA4CRCA4AKIAAIIO3I4t 44543 DAAAAJ AMA 43341 COP Drive shaft Now heres funand will benefit experience started using standard boat pans off shelfi 3/16-in dia drive shaft screw-on universal front prop connection Forget started making drive shafts various connection systems failed because setscrews flats drive shaft just wouldnt hold finally made -in drive shaft shown drawings connection rear drive shaft front universal part must keyed shown four big 4-28 setscrews alone wont hold couple flights way its shown drawings works fine has no loosening connection since parts keyed People always asking about vibration long drive shaft no problems Theres no vibration airplane conventional engine/prop connection fact flywheel effect drive shaft seems make things smoother usual Retractable landing gear As mentioned earlier Goldberg retracts used P-39 nose gear strut will have extended length shown drawing No 1 other modifi cations addition extra helper spring nose gear two helper springs outboard main gear Remember have centrifugal force contend Control Line model best way check see have enough strength balance force stand airplane its outboard wing tip will simulate G outward force operate adjust springs until gear works easily landing gear operating servo Power Driver manufactured Wing Manufacturing Co should able order through local hobby shop modified give power travel replacing plastic jack screw longer brass-threaded rod also replaced plastic gears brass ones give higher gear ratio changed May 198267 aSzLThvesAr itt 4995 99544.9. aa T mexone exnauas manvorn ana TUDS macion TO engine wirn silicone sealer keep oil contaminating inside fuselage ran ana raumalura txire ranietor lanhi ian auueu uciure Ijuing LU Inc 1981 Nats Texas AIr passes over corrugated brass surface bottom aft fuselage isnt added permanently until quite late constructionRudder elevator surfaces covered heavy silkspan Engine Elevator pushrod installed adjusted pointand cooling system sit under cockpit belicrank wing powerful motor run 6 volts Operating three landing gears off servo takes pretty powerful servo Another point make gear retracts near scale time instead snapping jerking up down often see models Flight judges should give full points realistically operating retracts Control system look plans see bellcrank located out wing know what youre going sayhes Out mind worry same system has worked per fectly Mustang 11 years works perfectly Cobra too reason location twofold First cant have control lines running through main gear wheel wells interfering things Secondly frees up space inside wing center section landing gear operating mechanisms entire control system shown drawing sheet No 2 looks like Rube Carl Goldberg know works fine allows us following three control lines release parking brake ready takeoff apply brakes taxiing advance retard throttle retract extend landing gear will operate flight controls system really dont need helper get started fly Just start engine let sit idle parking brake set go out pick up control handle apply full up elevator release brake add little power taxi takeoff position Full down elevator applies brake stopping Electrical system dont know people fool around complicated mechanical airoperated retract systems something simple shown drawing sheet No 2 possible key components good powerful servo off-the-shelf stuff supplier such Radio Shack course system wasnt possible until decade ago inexpensive mini diodes became available 68 Model Aviation Forward tuselage ready receive engine cooling system Note ply nose former removable access forward drive shaft bearings Aft fuselage tail ready joining main fuselage Plywood core balsa rib construction light very durable Drive snart assemoly LefttO right universal connection thrust bearing rear bearing block pulley drive radiator fan front bearing prop drive hub setup worked best several tried Drive shaft main front bearing disassembled Two ball bearings used Pins prop drive hub match holes prop spinner backplate allow reverse current bypass limit switches operating landing gear Also note master switch shown circuit absolutely essential prevent accidental retraction landing gear also shut off system may adjusting lever throw landing gear doors etc Please note however must turn want retract gear flight cost dearly 1981 Nats overlooked spite printed check list fly best flight gear down blew potential 20 points off near-90 flight score electrical circuit scheme shows exterior plug-in starting battery However since drawings made have eliminated external starting battery completely Instead just installed extra pencell inside plane turned external switch heats plug continuously during flight gives extra few hundred rpm full throttle no flood-out reiy low idle battery lasts haIfa dozen flights Now have to start turn ignition switch hit starter Construction Well lets face build airplane have half smart half stupid good craftsman lover realism Control Line flying dont meet quali fications go oi next article still go dont have whole lot say about construc tion Cobra because detailed drawings complete could Study drawings theyll answer questions Note fuselage chassis offset almost four degrees right done two very important reasons First provides necessary outward thrust good line tension second makes room exhaust manifold exhaust pipe wing removable two very important reasons First youre going contest cramped four-wheel motorcycles have drive days can put bird inside instead having strap roof second reason removable wing important accessibility Scale model kind have able get operating parts systems repair main tenance really dont want have cut beautiful fuselage wing get faulty servo Thats Ive located landing gear servo other systems top wing center section repairs adjustments necessary just remove two bolts release couple connections voila exposed ready fixed Wing construction style Al Rabe super way build straight wing use couple of-in 0 D aluminum tubes about five feet long set whole thing up wing still jig installed landing gear makes easier check wheel align ment strut length etc found easier build fuselage back former G mate wing point waiting until very last build aft fuselage tail section Youll picking plane up turning over hundreds times during construction have rear half airplane way during have favorite ways construct fuselage Ive seen em allcarved slabs sheet planks fiberglass molded balsa etc baby ran across composite method worked out well First cut 3/32 planking about 5/16 wide went planking away Its hard rough-sanded filled bad places DAP spackling compound cheap available local paint store stuff good because water sol uble can worked smoothed place finger dipped water After glop dries sand everything final shape apply 2oz glass cloth polyester resin After has cured sand smooth Mix up thick batch DAP water paint whole fuselage fill rough areas fiberglass job Give final sanding spray two coats urethane paint Thats Lightweight super strong beautiful finish Flying Cobra Now comes moment truth Youve put time effort building youre ready get air White knuckles shaky knees Non en per speriorum no sweat craft good flier youre ready takeoff release brake feed power slowly until feel resistance retract switch against throttle line Let build up speed half lap gently ease small amount up elevator shell come off ground realistic manner May 198269 Jack tolly wanted mount engine scale positionunder cockpitso designed built radiator system cool water-jacketed Enya 45 marine engine P-39 No wonder took Special Achievement Award 1981 Nats presented bythe National Associ ation Scale Aeromodelers Several different drive shafts tried redesigned too Continued page 132 Rear drive shaft showing universal drive pin ball thrust bearing Nylon rear bearing block takes thrust drive pin would pull out universal joint Front end drive shaft shows main front bearing prop drive hub pins engage prop spinner backplate win-power 2 Blade Tractor 545354Us 6364iSo 747678Us 848688lOs 949697 98104106needs 11411-6118SI 124125126*110 2 Blade PusherAT YOUR DEALER 5% 3 54 63 64 lOs 86 Us 9610-6 *1 3 BladeTractor 53 63 64 Us 3 BladePusher 63 3iade MetallicAluminum Color Tractor 76 78 51 8688 *ia 96 106104 fl Pusher06 *110 - & PARTS CRICKET KIT$19995 wflrwine Eng*27995 w/K & B 35 Eng*29995 *includes heat sink & muffler built-up radios RTF avaIlable prices Call 412-342-574O GRISH LARGE WOOD PROPELLERS HARDWOOD too hard minimizes chance costly plane engine damage True pitch airfoil fully finished balanced ready coating 3/8 BOREALL SIZES IN18 S7 6 B 10 12 PITCH 208 2210 2413 formation national organization Control Line new try national coalition organization will mean sacrificing some speed progress others great deal individual identity groups possibly certain leaders contrast Speed Team Race fraternities have virtually nothing lose participation great deal gain would nice see some type organization moving improve declining Speed fraternity interested send SASE Gazette 707 2nd Street Davis CA 95616 Contest Before ending would like mention Northwest Regionals Eugene OR May29 30 1982 big shoot-out Northwest Mike Hazel CD planning have Speed events year Now chance Speed modelers support event information send SASE Mike Hazel 1040 Windemere Drive NW Salem OR 97304 next two columns will special FAI Speed series will cover both model design engine setup Happy Flying Gene Hempet 301 N Yale Dr Garlana TX 75042 P-39 Airacobra/Stolly Continued page 69 Right after breaking ground push throttle rest wayand gear coming up fighter jock style After initial climb-out pull throttle back three quarters cruise use full power climbing maneuvers makes realistic flight No tricky stuff very stable havent looped yet tells can indeed nice wide realistic loop Mus tang same weight identical areas movements goes loop realistic fashion trying imitate Stunt boys because real airplanes dont way anyhow first flight P-39 left front cowling cockpit section off sure adequate cooling extra nose weight still three-wheel race car took whole lap before built up enough speed get air Nose heavy moved batteries back station G balanced perfectly Because weight nose gear moving rear after retraction its better flier gear up Landings easy about half power As soon main gear touches down nose drops finished flyingbuilt-in nobounce system Thats way its supposed 132 Model Aviation NW aMp GONTIILIII TillS PROFILE0 COMBA PRA T WIDE & NARROW WEDGE 15 -- 6 oz Capacities INIFLOW & STINDD Custom Dliii lisle Ingredients detailed brochure50C stamps/check CAROLINA TAFFINDER 8345 Delhi Road Charleston Hgts SC 29405 45-60 Powered Sport Competition Flying Complete Parts Support HIROBO SCALE HEUCOPTERS 50-60 Powered Tow Cobra Ranger Lama uois ultimate scale helicopters PLAZA HOBBYCRAFT p473 E State Street Sharon PA 16146 fornddo PROPELLERS Made polyester boil color Go GRISH propeller True helical pitch airfoil Sizes pitches styles RIGHT HAND TRACTOR NEW SIZE IN 8 & 10 PITCH 28 516 GRISH~iHN INDIANA 46373 Some philosophy first Control Line plane Jim Walker Fireball 1942 Black market purchase paper route money Sev eral years models later breezed through Air Force Pilot Training much help model flying experiences fact stationed remote far-flung Air Force bases always found fellow pilots model builders Control Line flying nearest thing flying real plane have feel plane hand throttle brakes re tracts heavy Scale plane its same old feeling bringing real bird down final approach landing Im knocking RC much fun Besides get satis faction designing building own bird feel sorry guys other modeling fields miss half fun satisfaction being modeler Recently P-39 took first place Cincin nati OH contest struck certain amount pride judges asked parts plane actually made could truthfully answer Only engine wheels prop spinner sir greatest satis faction modeling came Texas Nats last year P-39 won NASA National Association Scale Aeromodelers Special Achievement Award made worth give credit credit due however would have possible understanding helpful wife pit person Thanks Naomi Documentation intend compete P-39 Airacobra youll need three-view drawings etc called AMA rule book source Historical nation Album published Paul R Matt PO Box 33 Temple City CA 91780 Space Shuttle Il/Hux Continued page 72 shuttle youll find interesting models around friend has described shuttle controlled falling body Thats pretty accurate design resists stalling preferring level sink larger light weight model looks like actually flying rather falling Both smaller will immediately upright themselves attitude flight Enough Rockwells design Since have expressed interest larger shuttle plans 1/48 plans quite similar original 1/72 drawings pay careful attention differences Use JET HAWK F4 PHANTOMFAGLE HUNDERBIRD REVENGEAlL II TLAS BOOTLEGGETO ZLI -5O L LASER 0 KIN pA dYIG OBRA $3P THAWK HArH THUNDERB RD RI EN TI U ATLAS i300TL GOF OP&JOR ZLIN Z OL LASER 20 NTST P- B FLYING TIG P PLANE JAN AAt Local Dealer Send $100 Catalog v i 1 May 1982 133 IN STOCK FOR IMMEDIATE SHIPMENT NewSUPER QUADRA$9995 wth BRISIGHELLA FLYWHEEL 996 QUADRA MARINE engine 495 QUADRA RSPAIR$1000 plot petit KIORITZ engine 244 cc in$19995 Jim Mccc, ERCOUPEPLANS $2395 KIT $22995 Jin Mccc, TOMAHAWKPLANS $2395 KIT $23995 BALSA end BASSWOOD cli niece35% OFF Concept FLEETKIT $17995 FG Cowl $1995 QUADRA fole tenke16 oc $696 32 cc $795 VICKERS LEWIS MACHINE GUN KITS$1496 10 die COVERED WHEELS USA Pop$2596 PLAAISs SUPER STEARMAN Godfrey$2800 STARDUSTER TOO Brieghellc$2996 conic J3 CUB NeIi$2995 VOLKSPLANE Chioken CIterlie$2195 FLY BABY $1896 SES Reocohl$Z495 COCKPIT KITS Tonehcwk F4U-1 Spittre$2195 Eronope $1795 Stearteen $2096 Citebrie $2496 J-3 Cob $1950 ME109 $2150 Fleet $1996 FIBERGLASS ARROW SHAFTS 5/16 032 IgB/$1000 24-Hour Service. Add $250 postage Send Bank Check Money Order JIM MESSERS QUALITY MODEL PRODUCTS 106 Valley View Dr Allegany NY 14706
Edition: Model Aviation - 1982/05
Page Numbers: 65, 66, 67, 68, 69, 132, 133
At 1981 Nats NASA Special Achievement Award went bird P-39 Airacobra engine mounted behind cockpit water-cooled connected prop through drive shaft CL Sport Scale model indeed special THE FIRST TIME saw P-39 flight must have 1941 near Wright Field sound engine speed clean lines different radial-engined P shooters biplanes common days awestruck have fas cinated its unique design ever since P-39 Americas first-line pur suit planes time Pearl Harbor Decem ber 1941 made its initial flight April 1938 Wright Field time Pearl Harbor attack nearly 600 built Its unique engine location behind cockpit caused some concern first experience showed no hazard crash landing engine located forward cockpit However P-39s spin charac teristics could quite problem proper recovery techniques ignored Airacobra saw combat throughout world particularly Southwest Pacific Mediterranean Russian theaters Because its engine equipped supercharger P-39 performed best below 17000 feet often used lower altitudes ground strafing P-39 production ended August 1944 Bell built 9584 4773 allotted Soviet Union Russian pilots appreciated P-39 its 37mm cannon its ground attack capabilities against German armored forces nwdel Several years ago decided design build Sport Scale model P39 concept simple enough air-cooled engine sticking out breeze up front retracts throttle control Id very good performance lots fun similar model P-5 1 Mustang built Al Rabes plans equipped retracts throttle control Sport Scale came along Mustang started winning first place trophies contests came design time just couldnt see pretty Cobra lines being dirtied up engine sitting up nose decided move engine back cockpit area like real air-cool leaving windows Out around wind screen Full-size drawings started construction chassis wing proceeding almost concurrently drawings P-39 Thafs happened run across article RC magazine some folks experimenting liquidcooled engines flowthrough radiator system Th- U Model sits runway Wright Field original P39 made maiden flight 1938 Enya 45 marine engine Sits amidships scale location drive shaft extends forward prop results getting convinced go liquid-cooled setup P-39 allowing close cockpit windows should As luck would have found Goldberg retracts would just barely fit machine didnt have design build own did Mustang scale P-39 sized 3-in diameter spinner 3-in diameter main gear wheels would proper scale Too times see good looking airplane spoiled wrong size wheels end piece music wire Landing gears should look like landing gears Before commenting construction air frame Id like describe major systems plane leaming experiences during past year Cooling system little apprehensive about everyone said would work Still took lot nerve fire up brand new Enya 45 first time Id run minute two shut off see radiator getting heat went getting braver time As tumed out cooling system thing airplane has given no problems works beautifully However decided take Texas Nats past summer started thinking about 100-degree heat decided add extra cooling capacity extra radiator tank mounted alongside fan radiator area batteries landing gear servo shown drawing sheet No 1 batteries moved back sit top chassis just front former G better balance second radiator tank detailed drawing No 2 Robart pumper has done its job well pumping coolant through system dont know what makes little things work whats inside safe side keep cool possible mounted between cool outlet fan radiator inlet engine cooling jacket use undiluted antifreeze fear diluting water may cause steam problems system 66 Model Aviation / tIEVI - p _____________________________________________________ p--i 7 A___1 SE nt .5J Left right ianaing gear servo batteries exnaust tube tuci tank engine radiators fan Tube ducts exhaust out bottom plane nuuan aueueusrankCase preure move antifreeze radiator engine note wire clamps ail tube connections FULL-SIZE PLANSAVAILABLE . SEE PAGE 140 -a rr C Sn a_ VSRITM arSLaIBQ524L3LDERL& NOSEAAAEEL 4474444 4444499 5 3 2Zt~ 94344454A 19 rCa &aaAaaaAfl99 - OSIELL 3J AGtAUG5OtA 4CAI 343-I-4 CANTAA144 SPORT SCALPI CAL 44443 MAlI BAA4CRCA4AKIAAIIO3I4t 44543 DAAAAJ AMA 43341 COP Drive shaft Now heres funand will benefit experience started using standard boat pans off shelfi 3/16-in dia drive shaft screw-on universal front prop connection Forget started making drive shafts various connection systems failed because setscrews flats drive shaft just wouldnt hold finally made -in drive shaft shown drawings connection rear drive shaft front universal part must keyed shown four big 4-28 setscrews alone wont hold couple flights way its shown drawings works fine has no loosening connection since parts keyed People always asking about vibration long drive shaft no problems Theres no vibration airplane conventional engine/prop connection fact flywheel effect drive shaft seems make things smoother usual Retractable landing gear As mentioned earlier Goldberg retracts used P-39 nose gear strut will have extended length shown drawing No 1 other modifi cations addition extra helper spring nose gear two helper springs outboard main gear Remember have centrifugal force contend Control Line model best way check see have enough strength balance force stand airplane its outboard wing tip will simulate G outward force operate adjust springs until gear works easily landing gear operating servo Power Driver manufactured Wing Manufacturing Co should able order through local hobby shop modified give power travel replacing plastic jack screw longer brass-threaded rod also replaced plastic gears brass ones give higher gear ratio changed May 198267 aSzLThvesAr itt 4995 99544.9. aa T mexone exnauas manvorn ana TUDS macion TO engine wirn silicone sealer keep oil contaminating inside fuselage ran ana raumalura txire ranietor lanhi ian auueu uciure Ijuing LU Inc 1981 Nats Texas AIr passes over corrugated brass surface bottom aft fuselage isnt added permanently until quite late constructionRudder elevator surfaces covered heavy silkspan Engine Elevator pushrod installed adjusted pointand cooling system sit under cockpit belicrank wing powerful motor run 6 volts Operating three landing gears off servo takes pretty powerful servo Another point make gear retracts near scale time instead snapping jerking up down often see models Flight judges should give full points realistically operating retracts Control system look plans see bellcrank located out wing know what youre going sayhes Out mind worry same system has worked per fectly Mustang 11 years works perfectly Cobra too reason location twofold First cant have control lines running through main gear wheel wells interfering things Secondly frees up space inside wing center section landing gear operating mechanisms entire control system shown drawing sheet No 2 looks like Rube Carl Goldberg know works fine allows us following three control lines release parking brake ready takeoff apply brakes taxiing advance retard throttle retract extend landing gear will operate flight controls system really dont need helper get started fly Just start engine let sit idle parking brake set go out pick up control handle apply full up elevator release brake add little power taxi takeoff position Full down elevator applies brake stopping Electrical system dont know people fool around complicated mechanical airoperated retract systems something simple shown drawing sheet No 2 possible key components good powerful servo off-the-shelf stuff supplier such Radio Shack course system wasnt possible until decade ago inexpensive mini diodes became available 68 Model Aviation Forward tuselage ready receive engine cooling system Note ply nose former removable access forward drive shaft bearings Aft fuselage tail ready joining main fuselage Plywood core balsa rib construction light very durable Drive snart assemoly LefttO right universal connection thrust bearing rear bearing block pulley drive radiator fan front bearing prop drive hub setup worked best several tried Drive shaft main front bearing disassembled Two ball bearings used Pins prop drive hub match holes prop spinner backplate allow reverse current bypass limit switches operating landing gear Also note master switch shown circuit absolutely essential prevent accidental retraction landing gear also shut off system may adjusting lever throw landing gear doors etc Please note however must turn want retract gear flight cost dearly 1981 Nats overlooked spite printed check list fly best flight gear down blew potential 20 points off near-90 flight score electrical circuit scheme shows exterior plug-in starting battery However since drawings made have eliminated external starting battery completely Instead just installed extra pencell inside plane turned external switch heats plug continuously during flight gives extra few hundred rpm full throttle no flood-out reiy low idle battery lasts haIfa dozen flights Now have to start turn ignition switch hit starter Construction Well lets face build airplane have half smart half stupid good craftsman lover realism Control Line flying dont meet quali fications go oi next article still go dont have whole lot say about construc tion Cobra because detailed drawings complete could Study drawings theyll answer questions Note fuselage chassis offset almost four degrees right done two very important reasons First provides necessary outward thrust good line tension second makes room exhaust manifold exhaust pipe wing removable two very important reasons First youre going contest cramped four-wheel motorcycles have drive days can put bird inside instead having strap roof second reason removable wing important accessibility Scale model kind have able get operating parts systems repair main tenance really dont want have cut beautiful fuselage wing get faulty servo Thats Ive located landing gear servo other systems top wing center section repairs adjustments necessary just remove two bolts release couple connections voila exposed ready fixed Wing construction style Al Rabe super way build straight wing use couple of-in 0 D aluminum tubes about five feet long set whole thing up wing still jig installed landing gear makes easier check wheel align ment strut length etc found easier build fuselage back former G mate wing point waiting until very last build aft fuselage tail section Youll picking plane up turning over hundreds times during construction have rear half airplane way during have favorite ways construct fuselage Ive seen em allcarved slabs sheet planks fiberglass molded balsa etc baby ran across composite method worked out well First cut 3/32 planking about 5/16 wide went planking away Its hard rough-sanded filled bad places DAP spackling compound cheap available local paint store stuff good because water sol uble can worked smoothed place finger dipped water After glop dries sand everything final shape apply 2oz glass cloth polyester resin After has cured sand smooth Mix up thick batch DAP water paint whole fuselage fill rough areas fiberglass job Give final sanding spray two coats urethane paint Thats Lightweight super strong beautiful finish Flying Cobra Now comes moment truth Youve put time effort building youre ready get air White knuckles shaky knees Non en per speriorum no sweat craft good flier youre ready takeoff release brake feed power slowly until feel resistance retract switch against throttle line Let build up speed half lap gently ease small amount up elevator shell come off ground realistic manner May 198269 Jack tolly wanted mount engine scale positionunder cockpitso designed built radiator system cool water-jacketed Enya 45 marine engine P-39 No wonder took Special Achievement Award 1981 Nats presented bythe National Associ ation Scale Aeromodelers Several different drive shafts tried redesigned too Continued page 132 Rear drive shaft showing universal drive pin ball thrust bearing Nylon rear bearing block takes thrust drive pin would pull out universal joint Front end drive shaft shows main front bearing prop drive hub pins engage prop spinner backplate win-power 2 Blade Tractor 545354Us 6364iSo 747678Us 848688lOs 949697 98104106needs 11411-6118SI 124125126*110 2 Blade PusherAT YOUR DEALER 5% 3 54 63 64 lOs 86 Us 9610-6 *1 3 BladeTractor 53 63 64 Us 3 BladePusher 63 3iade MetallicAluminum Color Tractor 76 78 51 8688 *ia 96 106104 fl Pusher06 *110 - & PARTS CRICKET KIT$19995 wflrwine Eng*27995 w/K & B 35 Eng*29995 *includes heat sink & muffler built-up radios RTF avaIlable prices Call 412-342-574O GRISH LARGE WOOD PROPELLERS HARDWOOD too hard minimizes chance costly plane engine damage True pitch airfoil fully finished balanced ready coating 3/8 BOREALL SIZES IN18 S7 6 B 10 12 PITCH 208 2210 2413 formation national organization Control Line new try national coalition organization will mean sacrificing some speed progress others great deal individual identity groups possibly certain leaders contrast Speed Team Race fraternities have virtually nothing lose participation great deal gain would nice see some type organization moving improve declining Speed fraternity interested send SASE Gazette 707 2nd Street Davis CA 95616 Contest Before ending would like mention Northwest Regionals Eugene OR May29 30 1982 big shoot-out Northwest Mike Hazel CD planning have Speed events year Now chance Speed modelers support event information send SASE Mike Hazel 1040 Windemere Drive NW Salem OR 97304 next two columns will special FAI Speed series will cover both model design engine setup Happy Flying Gene Hempet 301 N Yale Dr Garlana TX 75042 P-39 Airacobra/Stolly Continued page 69 Right after breaking ground push throttle rest wayand gear coming up fighter jock style After initial climb-out pull throttle back three quarters cruise use full power climbing maneuvers makes realistic flight No tricky stuff very stable havent looped yet tells can indeed nice wide realistic loop Mus tang same weight identical areas movements goes loop realistic fashion trying imitate Stunt boys because real airplanes dont way anyhow first flight P-39 left front cowling cockpit section off sure adequate cooling extra nose weight still three-wheel race car took whole lap before built up enough speed get air Nose heavy moved batteries back station G balanced perfectly Because weight nose gear moving rear after retraction its better flier gear up Landings easy about half power As soon main gear touches down nose drops finished flyingbuilt-in nobounce system Thats way its supposed 132 Model Aviation NW aMp GONTIILIII TillS PROFILE0 COMBA PRA T WIDE & NARROW WEDGE 15 -- 6 oz Capacities INIFLOW & STINDD Custom Dliii lisle Ingredients detailed brochure50C stamps/check CAROLINA TAFFINDER 8345 Delhi Road Charleston Hgts SC 29405 45-60 Powered Sport Competition Flying Complete Parts Support HIROBO SCALE HEUCOPTERS 50-60 Powered Tow Cobra Ranger Lama uois ultimate scale helicopters PLAZA HOBBYCRAFT p473 E State Street Sharon PA 16146 fornddo PROPELLERS Made polyester boil color Go GRISH propeller True helical pitch airfoil Sizes pitches styles RIGHT HAND TRACTOR NEW SIZE IN 8 & 10 PITCH 28 516 GRISH~iHN INDIANA 46373 Some philosophy first Control Line plane Jim Walker Fireball 1942 Black market purchase paper route money Sev eral years models later breezed through Air Force Pilot Training much help model flying experiences fact stationed remote far-flung Air Force bases always found fellow pilots model builders Control Line flying nearest thing flying real plane have feel plane hand throttle brakes re tracts heavy Scale plane its same old feeling bringing real bird down final approach landing Im knocking RC much fun Besides get satis faction designing building own bird feel sorry guys other modeling fields miss half fun satisfaction being modeler Recently P-39 took first place Cincin nati OH contest struck certain amount pride judges asked parts plane actually made could truthfully answer Only engine wheels prop spinner sir greatest satis faction modeling came Texas Nats last year P-39 won NASA National Association Scale Aeromodelers Special Achievement Award made worth give credit credit due however would have possible understanding helpful wife pit person Thanks Naomi Documentation intend compete P-39 Airacobra youll need three-view drawings etc called AMA rule book source Historical nation Album published Paul R Matt PO Box 33 Temple City CA 91780 Space Shuttle Il/Hux Continued page 72 shuttle youll find interesting models around friend has described shuttle controlled falling body Thats pretty accurate design resists stalling preferring level sink larger light weight model looks like actually flying rather falling Both smaller will immediately upright themselves attitude flight Enough Rockwells design Since have expressed interest larger shuttle plans 1/48 plans quite similar original 1/72 drawings pay careful attention differences Use JET HAWK F4 PHANTOMFAGLE HUNDERBIRD REVENGEAlL II TLAS BOOTLEGGETO ZLI -5O L LASER 0 KIN pA dYIG OBRA $3P THAWK HArH THUNDERB RD RI EN TI U ATLAS i300TL GOF OP&JOR ZLIN Z OL LASER 20 NTST P- B FLYING TIG P PLANE JAN AAt Local Dealer Send $100 Catalog v i 1 May 1982 133 IN STOCK FOR IMMEDIATE SHIPMENT NewSUPER QUADRA$9995 wth BRISIGHELLA FLYWHEEL 996 QUADRA MARINE engine 495 QUADRA RSPAIR$1000 plot petit KIORITZ engine 244 cc in$19995 Jim Mccc, ERCOUPEPLANS $2395 KIT $22995 Jin Mccc, TOMAHAWKPLANS $2395 KIT $23995 BALSA end BASSWOOD cli niece35% OFF Concept FLEETKIT $17995 FG Cowl $1995 QUADRA fole tenke16 oc $696 32 cc $795 VICKERS LEWIS MACHINE GUN KITS$1496 10 die COVERED WHEELS USA Pop$2596 PLAAISs SUPER STEARMAN Godfrey$2800 STARDUSTER TOO Brieghellc$2996 conic J3 CUB NeIi$2995 VOLKSPLANE Chioken CIterlie$2195 FLY BABY $1896 SES Reocohl$Z495 COCKPIT KITS Tonehcwk F4U-1 Spittre$2195 Eronope $1795 Stearteen $2096 Citebrie $2496 J-3 Cob $1950 ME109 $2150 Fleet $1996 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