ACHIEVING smooth dependable throttle con trol over two three four engines obvious challenge multi-engined scale can mind-bending enough times get just engine idle accelerate properly no matter good carbure tor long before can think about making adjustments must construct reliable system opening closing engine throt ties unison drawings page illustrate what believe three best workable multi-throttle linkage systems will find use three designed operate standard 3-line G-S J-Roberts bellcrank system flight proven time tested Which best multi-engined projects may considering will depend own preferences dictates particular subject aircraft Lets take close look Method submitted Ken Long Whittier California set-up Ken used twin-engined Japanese Betty Bomber has flown last two Nationals winning 4th 2nd Precision Scale Ken uses simple arrangement bellcranks pushrods drive two carburetors off single bellcrank unit drawing pretty easy follow however note 900 bellcranks must installed get proper direction travel carburetor pushrod also important pushrods run 900 bellcranks carbs adjustable length engines can synchronized open close exactly same time 900 bellcranks standard RC hardware can find hobby shopsGold berg Sig Du-Bro Rocket City Williams Brothers whod miss market similar equally suitable versions adjustable pushrod might consider RC Links some times called devises Kwik-Links Thread ed Rods typically 1012 long also marketed several companies basically similar may some instances however will feasible use stiff wire pushrod engine because nacelle structure landing gear fuel tank may way case flexible cable type pushrod such Sig SH-560 Du-Bro *165 Su-Pr-Line *169 should used consist inner braided steel cable adjustable link end fixed solder link other relatively loose fitting outer plastic tubing sleeve inside cable slides Depending degree upon exact diameter cable plastic sleeve type pushrod can detoured around obstacles loosing much its free movement Method II P-61 Black Widow Jeff Perez Lamed Kansas used win Sport Scale event 77 Nationals used torque rod arrangement similar shown operate both twin throttles flaps torque rod bushed rotating rod tube running spanwise through wing has several control horns soldered onto torque rod driven middle control horn via short pushrod standard 3-line bellcrank As rotates turn moves pushrods engines flaps torque rod can made hard brass tubing5/32 OD minimum Cut few short pieces next size larger brass tubing would 3/16 OD 5/32 ID use bearings should epoxied solidly wing ribs horns should cut brass steel sheet soldered torque rod long life material horns should 1/16 thick K&S Engineering Co probably brand name tubing using also markets 1/4 1/2 wide X 12long brass strips thickness making horns simply matter cutting strips length drilling proper holes ends torque rod pushrods As before pushrods going engines should adjustable adjustable link pushrod should engine end since torque rod itself will permanently enclosed within wing Method III last drawing illustrates set-up Jeff Perez using current project 4-engine B-I 7 Flying Fortress order help steer clear leadout cables tanks etc Jeff elected go entirely flexible cable pushrods like described Method Jeff said still plans link flaps throttles did torque-rod system time will use flexible cable too isnt first time Jeff has used flexible Continued page 117 METHOD t LARGE ARROWS INBICATE 11108 TOROTTLE DIRECTION FOR PASOROOG METHOD III FLEGIGLE CABLE PUSUROOS 3LINE BELLCRANX LARGE ARROWS INOICATE 01011 THROTTLE OIRECTIVNB FOR P0000000 STANOARO CL BELLE RANK 0 SOWN S 27K AND vi AG JA S TA RLE PASO ROB 400 BELLERANO JROBEBTG 3-LINE BELLERANE THROTTLE ARMS ON 010110 SHOE CARDS BUSIC WIRE P000000 CUT OFF THIS PART IF 0 GETS IN TUE WAY UNLESS yOU WANT TO USE IT FOB DRIVING FLAPS OR SOMETRING MAKE CURVES IN CABLE PUSORODS AS SRALLGW AG POSSIBLE TV MINIMIZE IN DING METHOD II TYPICAL BRASS BEARING EPOBO TO OTRAC TAR K -r FLAP P000000 48 Model Aviation BRASS BEAR NA HORN OROGE ROB / A OJ S TA BL E PA SB ROD BRASS BEARING BE TAR 0 TI OpTYPICAL WING RIBS BEL LCR N K FLAPS ARE AP AT 111011 TOBOTTLE Multi-engined models have always popular CL scale Wankel-powered transport flown Russian contestant World Championships distinctive sound good power-to-weight ratio characteristic benefits multi-engines Bob Wischer photo between 20 21 ounces properties men- Different brands graphite lubricant tioned should achieved Only other prerequisite available both powder liquid versions hottest possible out-of-box engine Any l/2A hardware stores addition bellpylon racer no better its engine pilot crank instance its also helpful using flexible cable pushrods especially long ones work powdered graphite outer plastic sheathing before gluing pushrod ____________________________________ model can held vertically squirting graphite Better yet smear cable itself powder before sliding inside sheathing Next month coverage CL Scale 79 Nationals cables alone multi-throttle control Piper Twin Comnianche flew last years Nats type arrangement order get carburetors opening same direction engines right side model need have throttle arms reversed top carb two braided cables wrapped soldered center along short drive wire attaches bellcrank Note wire attached same bellcrank arm throttle leadout normal place Du-Bro threaded coup lers soldered carburetor end cable RC link goes gives necessary adjustment get engines working together important thing keep mind three control installations eliminate binding friction wherever pos sible system must work perfectly free smooth throughout its entire range maximum effectiveness dependability During steps assembly double check make sure building bind develops find cure before proceeding further parts control system have nylon-to-metal bearing surfaces shouldnt need extra lubrication However metal-to-metal surfaces such bellcrank normally use little graphite lubricant help make system work silky smooth Mike Gre*z Box 162 Montezuma IA 50171 CL Aerobatics/Paul continued page 49 Finish sanding 600 wet point plane should ready color coat intend continue epoxy paint spray base coat color want use nitrate butyrate dopes should first apply coat Aero Gloss clear over talcum powder coat Ac cording Paul base coats added about four ounces 57-in span plane 28 stab and47 fuselage Figure another fouroz use epoxy-type paint question recently asked about what special building M&P Stiletto kit First remember two runs kits first some bad ribs instructions little vague control hookup second run much better ribs Either way certain wing ribs true stack up Replace off Also may have cut out larger holes inboard ribs leadouts several Stilettos Les McDonald used two pushrods bellcrank going flap horn elevator horn gives less flap travel standard Nobler hookup actually 1-to-i ratio flap elevator what 95 percent stunt fliers use further illustrate simplified terms set up 1-to-i ratio connect pushrod bellcrank hole flap horn t pushrod flap horn elevator horn connected hole t point flap horn also pivot point elevator horn Dont forget brass bushings long life horns bellcrank pushrod should connect hole bellcrank approximately 3/4 bellcrank pivot Actually Top Flite bellcrank hole 11/16 Sig bellcrank hole about t point writer suggests kit builder follow 1-to-i setup first planes until can accumulate enough experience evaluate possible change different ratio Most Stiletto kits writer has seen have built using ST 46 engine wing area kit weight 48 54 oz can expect just makes sense use powerful engine certain allow tank 525 550 oz constructing front end fuselage means tank will 525 575 long Probably necessary substitution wood om block Several people have stated replaced bottom block two other pieces attempt cut October1979 117 CL Scale/Gretz continued page 48
Edition: Model Aviation - 1979/10
Page Numbers: 48, 117
ACHIEVING smooth dependable throttle con trol over two three four engines obvious challenge multi-engined scale can mind-bending enough times get just engine idle accelerate properly no matter good carbure tor long before can think about making adjustments must construct reliable system opening closing engine throt ties unison drawings page illustrate what believe three best workable multi-throttle linkage systems will find use three designed operate standard 3-line G-S J-Roberts bellcrank system flight proven time tested Which best multi-engined projects may considering will depend own preferences dictates particular subject aircraft Lets take close look Method submitted Ken Long Whittier California set-up Ken used twin-engined Japanese Betty Bomber has flown last two Nationals winning 4th 2nd Precision Scale Ken uses simple arrangement bellcranks pushrods drive two carburetors off single bellcrank unit drawing pretty easy follow however note 900 bellcranks must installed get proper direction travel carburetor pushrod also important pushrods run 900 bellcranks carbs adjustable length engines can synchronized open close exactly same time 900 bellcranks standard RC hardware can find hobby shopsGold berg Sig Du-Bro Rocket City Williams Brothers whod miss market similar equally suitable versions adjustable pushrod might consider RC Links some times called devises Kwik-Links Thread ed Rods typically 1012 long also marketed several companies basically similar may some instances however will feasible use stiff wire pushrod engine because nacelle structure landing gear fuel tank may way case flexible cable type pushrod such Sig SH-560 Du-Bro *165 Su-Pr-Line *169 should used consist inner braided steel cable adjustable link end fixed solder link other relatively loose fitting outer plastic tubing sleeve inside cable slides Depending degree upon exact diameter cable plastic sleeve type pushrod can detoured around obstacles loosing much its free movement Method II P-61 Black Widow Jeff Perez Lamed Kansas used win Sport Scale event 77 Nationals used torque rod arrangement similar shown operate both twin throttles flaps torque rod bushed rotating rod tube running spanwise through wing has several control horns soldered onto torque rod driven middle control horn via short pushrod standard 3-line bellcrank As rotates turn moves pushrods engines flaps torque rod can made hard brass tubing5/32 OD minimum Cut few short pieces next size larger brass tubing would 3/16 OD 5/32 ID use bearings should epoxied solidly wing ribs horns should cut brass steel sheet soldered torque rod long life material horns should 1/16 thick K&S Engineering Co probably brand name tubing using also markets 1/4 1/2 wide X 12long brass strips thickness making horns simply matter cutting strips length drilling proper holes ends torque rod pushrods As before pushrods going engines should adjustable adjustable link pushrod should engine end since torque rod itself will permanently enclosed within wing Method III last drawing illustrates set-up Jeff Perez using current project 4-engine B-I 7 Flying Fortress order help steer clear leadout cables tanks etc Jeff elected go entirely flexible cable pushrods like described Method Jeff said still plans link flaps throttles did torque-rod system time will use flexible cable too isnt first time Jeff has used flexible Continued page 117 METHOD t LARGE ARROWS INBICATE 11108 TOROTTLE DIRECTION FOR PASOROOG METHOD III FLEGIGLE CABLE PUSUROOS 3LINE BELLCRANX LARGE ARROWS INOICATE 01011 THROTTLE OIRECTIVNB FOR P0000000 STANOARO CL BELLE RANK 0 SOWN S 27K AND vi AG JA S TA RLE PASO ROB 400 BELLERANO JROBEBTG 3-LINE BELLERANE THROTTLE ARMS ON 010110 SHOE CARDS BUSIC WIRE P000000 CUT OFF THIS PART IF 0 GETS IN TUE WAY UNLESS yOU WANT TO USE IT FOB DRIVING FLAPS OR SOMETRING MAKE CURVES IN CABLE PUSORODS AS SRALLGW AG POSSIBLE TV MINIMIZE IN DING METHOD II TYPICAL BRASS BEARING EPOBO TO OTRAC TAR K -r FLAP P000000 48 Model Aviation BRASS BEAR NA HORN OROGE ROB / A OJ S TA BL E PA SB ROD BRASS BEARING BE TAR 0 TI OpTYPICAL WING RIBS BEL LCR N K FLAPS ARE AP AT 111011 TOBOTTLE Multi-engined models have always popular CL scale Wankel-powered transport flown Russian contestant World Championships distinctive sound good power-to-weight ratio characteristic benefits multi-engines Bob Wischer photo between 20 21 ounces properties men- Different brands graphite lubricant tioned should achieved Only other prerequisite available both powder liquid versions hottest possible out-of-box engine Any l/2A hardware stores addition bellpylon racer no better its engine pilot crank instance its also helpful using flexible cable pushrods especially long ones work powdered graphite outer plastic sheathing before gluing pushrod ____________________________________ model can held vertically squirting graphite Better yet smear cable itself powder before sliding inside sheathing Next month coverage CL Scale 79 Nationals cables alone multi-throttle control Piper Twin Comnianche flew last years Nats type arrangement order get carburetors opening same direction engines right side model need have throttle arms reversed top carb two braided cables wrapped soldered center along short drive wire attaches bellcrank Note wire attached same bellcrank arm throttle leadout normal place Du-Bro threaded coup lers soldered carburetor end cable RC link goes gives necessary adjustment get engines working together important thing keep mind three control installations eliminate binding friction wherever pos sible system must work perfectly free smooth throughout its entire range maximum effectiveness dependability During steps assembly double check make sure building bind develops find cure before proceeding further parts control system have nylon-to-metal bearing surfaces shouldnt need extra lubrication However metal-to-metal surfaces such bellcrank normally use little graphite lubricant help make system work silky smooth Mike Gre*z Box 162 Montezuma IA 50171 CL Aerobatics/Paul continued page 49 Finish sanding 600 wet point plane should ready color coat intend continue epoxy paint spray base coat color want use nitrate butyrate dopes should first apply coat Aero Gloss clear over talcum powder coat Ac cording Paul base coats added about four ounces 57-in span plane 28 stab and47 fuselage Figure another fouroz use epoxy-type paint question recently asked about what special building M&P Stiletto kit First remember two runs kits first some bad ribs instructions little vague control hookup second run much better ribs Either way certain wing ribs true stack up Replace off Also may have cut out larger holes inboard ribs leadouts several Stilettos Les McDonald used two pushrods bellcrank going flap horn elevator horn gives less flap travel standard Nobler hookup actually 1-to-i ratio flap elevator what 95 percent stunt fliers use further illustrate simplified terms set up 1-to-i ratio connect pushrod bellcrank hole flap horn t pushrod flap horn elevator horn connected hole t point flap horn also pivot point elevator horn Dont forget brass bushings long life horns bellcrank pushrod should connect hole bellcrank approximately 3/4 bellcrank pivot Actually Top Flite bellcrank hole 11/16 Sig bellcrank hole about t point writer suggests kit builder follow 1-to-i setup first planes until can accumulate enough experience evaluate possible change different ratio Most Stiletto kits writer has seen have built using ST 46 engine wing area kit weight 48 54 oz can expect just makes sense use powerful engine certain allow tank 525 550 oz constructing front end fuselage means tank will 525 575 long Probably necessary substitution wood om block Several people have stated replaced bottom block two other pieces attempt cut October1979 117 CL Scale/Gretz continued page 48