FREE FLIGHT SPORT SCALE 11 GEARS AND GEARLESS DRiVES Rubber Power Most fancy transmissions composed multiple motors driving prop through gears crank arrangements motor driving multiple props through similar devices have common trait modelers dont use em can increase models performance up 25% However unless light mechanically reliable relatively friction-free well-balanced used proper motor/prop combination can reduce performance significantly over simple direct drive great reasons employing odd power transfers size placement props leveling power curve reducing vibration caused long whipping motors compensating lack room long motor nacelle preventing stalls caused unwound motors shift CC rearward have number notable geared model successes competition around world recent years prestigious Flying Aces Club has gone far ban competition being unfair Hows recommendation Much has written about gears intend go deeply lengthy discussion topic complete obligatory math engineer types get Bill McCombs book Flying Improving Scale Models Send $1495 postage paid AIC Data POBox 763576 Dallas TX 75224 much however has written what Bob Thompson calls hovespian synchronized cranking devices Bruce Holbrooks hovespian Warp Drive Made Simple few years ago Dick Howard told about correspondent claimed fantastic Peanut flights using unusual drive system pleasure finally meeting Dicks friend Bruce Holbrook 1992 Flying Aces Nats have seen Warp Driveas calls itin action works performance Bruces Ryder R-6 92 FAC Nats certainly up expectation nor models probably due weight added extensive field repairs Ryder just undergone have making models long enough know Talking Dog Syndrome guy found talking dog chatted on until guy hired hail sold tickets dog refused say word very real phenomenon par Murphys Law mechanism smooth well-thought-out intriguing fact worked amazed everyone Bruce trying avoid dog owners experience wanted wait until scored competition triumph before presented detail modeling world leadership Flying Aces banned mechanical transmission devices before Bruce could prove mechanism wanted bit upset being let little setback get him down hes back improving device hopes others will inspired try themselves Bruce first got idea system exposed devices 30s employed concept nor seen ones modelers such Jack McCracken using days link multiple motors single prop drive Optimal Rubber Motor Too Much Tail Weight model prop rubber motor combination produces just enough power fly model well long time Too little motor results powered glide Too much motor adds weight yields loops short motor runs because motor unwinds faster prop can efficiently turn Start prop about /3 wingspan diameter average pitch experiment rubber size length Unfortunately can almost guarantee perfect motor will too long fit model can run rear motor peg way tail post still wont long enough Instead going aerodynamic explanations accept time being trying fit best motor model will make tail heavy start rubber motor Scale configuration designed balance heavy engine will result short nose long tail Since model has no heavy engine nothing up front balance weight scalelength fuselage behind wing weight optimal longand-strong rubber motor answer horizontal tailplane balance model could add airfoiled horizontal stabilizer slightly change angle flat tailplane disadvantage however varying lift varying speed whereas very little variation weight tail until motor runs out forward winds leaving heavy bunching long motor rear best solution move rubber weight tail front help replace missing weight scale engine Youd need parasitic ballast up anyway replace productive necessary rubber Diagram Worth Thousand Words Jim Kaman did much art column looked up hovespian dont know its Websters Unabridged says comes Latin meaning inexplicableor beyond comprehension Luckily drawings Bruces photos help explain inexplicable Study Warp Drive drawings well although possible variations once understand concept can experiment own Note putting smaller motors output common connecting rod plate forces operate long optimal motor replacing Its probably better due speed-leveling effect mechanism 92 Model Aviation e Holbrooks Rider R-6 Peanut opened up show Warp Warp Drive mechanism indicating relative size cranks Drive four rubber motors driving propeller position winding hook number-three crankshaft Having motors line connected linear conrod fit narrow nose Bruces Keith Rider R-6 racer follows same principle arranging circle common cranked plate think eight motors Bruce has used motors R-6 stretch-wound winding hook attached rod number three stack prop shaft can motor crankshafts made longer rest Bruces older models break half behind wing gain access motors latest however uses four-motorholding anchor rig inserted through nose removable stuffer stick locked place rear fuselage bamboo pin through centerjust like capturing normal rubber motor through-peg As long-mn motor exceptionally light model must top performance Splitting up Optimal Motor Weight Small Motors Moving weight forward get proper CC involves using shorter thicker motors Take loop Is-inch rubber optimum prop want fly Cut four motors piece would /32 Bill McCombs calculations show /32 motor will take twice number turns deliver 1/ torque 1/8-inch motor result 183% prop time 35% power Fully wound hand-launched model will slowly descend Increase motors thickness 59% making 050 inch thick decrease lengths 37% increases motors weight original /8-inch-loop same performance model now lighter Since no excess motor length tail no need use extra weight nose balance model will also longitudinally stable also true concentrating weight forward allows models recover minor upsets much quicker Reread section couple times understand concept trading lengthfor thickness want shorten can move weight forward want same weight rubber would have long optimal motor contrast 21 gearbox would use motor 59% thicker 63% long 21 gearing corresponds fourmotored Warp Drive torque burner efficient because needs thicker motors same effect Points Consider Building Warp Drive Try keep oh~TAILS CRANK I-TEFLON WASHER FIXED fl-TEFLON WASHER FREE IBRASS WASHER FIXED K-TEFLON TUBE BEARING IN ALUMINUM TUBE FOR WIND-CRANK DRIVE COLLECTOR PLATE ND DRIVE ilL ~TOR PLATE CON ROD IN NOVESPIAN MOTION AROUND AXES OF CRANKSHAFTS 4 OR 5 MOTORS AXIS lighter nose ballast its replacing connecting rod plate could made thin plywood aluminum hard balsa nonessential parts cut away drilled lightening mechanism should work quite freely commercial units remember old days might called sloppy crank-to-conrod clearances Make cranks close identical possible Bending jig would best way crank bit longer throw could bind up whole machine unless got really sloppy tolerances Provision must made cut friction caused rearward pull motor Teflon washers might best way go using two motor cranks connecting rod between third crank must added system just idler just keep connecting rod supported three points will go over-center motor crank third crank could used propeller attachment Bruce feels method winding several motors simultaneously takes no longer wind normal motor setup main contribution reviving synchronized cranking gearless transmission Id say help popularizing concept pretty big contribution well words .if snub-nosed short-coupled beauty tuming you know shell need lead prop fly Warp Drive may answer elevating quality love life fascinated Warp Drive idea wish discuss its fervent proponent Bruce Holbrook write him 108 Maypoint Rd Apt 11 West Royalty PEI Canada CIE ff6 Until next time gang keep CC belongs never use rubber prop can handle ________[LC _____________ Ji ftRDC I L November1994 93 rubbersiotora~6lo otots7 tube bantboo Rear AnciorAssem6 fo 1& lfrfreAlotors
Edition: Model Aviation - 1994/11
Page Numbers: 92, 93
FREE FLIGHT SPORT SCALE 11 GEARS AND GEARLESS DRiVES Rubber Power Most fancy transmissions composed multiple motors driving prop through gears crank arrangements motor driving multiple props through similar devices have common trait modelers dont use em can increase models performance up 25% However unless light mechanically reliable relatively friction-free well-balanced used proper motor/prop combination can reduce performance significantly over simple direct drive great reasons employing odd power transfers size placement props leveling power curve reducing vibration caused long whipping motors compensating lack room long motor nacelle preventing stalls caused unwound motors shift CC rearward have number notable geared model successes competition around world recent years prestigious Flying Aces Club has gone far ban competition being unfair Hows recommendation Much has written about gears intend go deeply lengthy discussion topic complete obligatory math engineer types get Bill McCombs book Flying Improving Scale Models Send $1495 postage paid AIC Data POBox 763576 Dallas TX 75224 much however has written what Bob Thompson calls hovespian synchronized cranking devices Bruce Holbrooks hovespian Warp Drive Made Simple few years ago Dick Howard told about correspondent claimed fantastic Peanut flights using unusual drive system pleasure finally meeting Dicks friend Bruce Holbrook 1992 Flying Aces Nats have seen Warp Driveas calls itin action works performance Bruces Ryder R-6 92 FAC Nats certainly up expectation nor models probably due weight added extensive field repairs Ryder just undergone have making models long enough know Talking Dog Syndrome guy found talking dog chatted on until guy hired hail sold tickets dog refused say word very real phenomenon par Murphys Law mechanism smooth well-thought-out intriguing fact worked amazed everyone Bruce trying avoid dog owners experience wanted wait until scored competition triumph before presented detail modeling world leadership Flying Aces banned mechanical transmission devices before Bruce could prove mechanism wanted bit upset being let little setback get him down hes back improving device hopes others will inspired try themselves Bruce first got idea system exposed devices 30s employed concept nor seen ones modelers such Jack McCracken using days link multiple motors single prop drive Optimal Rubber Motor Too Much Tail Weight model prop rubber motor combination produces just enough power fly model well long time Too little motor results powered glide Too much motor adds weight yields loops short motor runs because motor unwinds faster prop can efficiently turn Start prop about /3 wingspan diameter average pitch experiment rubber size length Unfortunately can almost guarantee perfect motor will too long fit model can run rear motor peg way tail post still wont long enough Instead going aerodynamic explanations accept time being trying fit best motor model will make tail heavy start rubber motor Scale configuration designed balance heavy engine will result short nose long tail Since model has no heavy engine nothing up front balance weight scalelength fuselage behind wing weight optimal longand-strong rubber motor answer horizontal tailplane balance model could add airfoiled horizontal stabilizer slightly change angle flat tailplane disadvantage however varying lift varying speed whereas very little variation weight tail until motor runs out forward winds leaving heavy bunching long motor rear best solution move rubber weight tail front help replace missing weight scale engine Youd need parasitic ballast up anyway replace productive necessary rubber Diagram Worth Thousand Words Jim Kaman did much art column looked up hovespian dont know its Websters Unabridged says comes Latin meaning inexplicableor beyond comprehension Luckily drawings Bruces photos help explain inexplicable Study Warp Drive drawings well although possible variations once understand concept can experiment own Note putting smaller motors output common connecting rod plate forces operate long optimal motor replacing Its probably better due speed-leveling effect mechanism 92 Model Aviation e Holbrooks Rider R-6 Peanut opened up show Warp Warp Drive mechanism indicating relative size cranks Drive four rubber motors driving propeller position winding hook number-three crankshaft Having motors line connected linear conrod fit narrow nose Bruces Keith Rider R-6 racer follows same principle arranging circle common cranked plate think eight motors Bruce has used motors R-6 stretch-wound winding hook attached rod number three stack prop shaft can motor crankshafts made longer rest Bruces older models break half behind wing gain access motors latest however uses four-motorholding anchor rig inserted through nose removable stuffer stick locked place rear fuselage bamboo pin through centerjust like capturing normal rubber motor through-peg As long-mn motor exceptionally light model must top performance Splitting up Optimal Motor Weight Small Motors Moving weight forward get proper CC involves using shorter thicker motors Take loop Is-inch rubber optimum prop want fly Cut four motors piece would /32 Bill McCombs calculations show /32 motor will take twice number turns deliver 1/ torque 1/8-inch motor result 183% prop time 35% power Fully wound hand-launched model will slowly descend Increase motors thickness 59% making 050 inch thick decrease lengths 37% increases motors weight original /8-inch-loop same performance model now lighter Since no excess motor length tail no need use extra weight nose balance model will also longitudinally stable also true concentrating weight forward allows models recover minor upsets much quicker Reread section couple times understand concept trading lengthfor thickness want shorten can move weight forward want same weight rubber would have long optimal motor contrast 21 gearbox would use motor 59% thicker 63% long 21 gearing corresponds fourmotored Warp Drive torque burner efficient because needs thicker motors same effect Points Consider Building Warp Drive Try keep oh~TAILS CRANK I-TEFLON WASHER FIXED fl-TEFLON WASHER FREE IBRASS WASHER FIXED K-TEFLON TUBE BEARING IN ALUMINUM TUBE FOR WIND-CRANK DRIVE COLLECTOR PLATE ND DRIVE ilL ~TOR PLATE CON ROD IN NOVESPIAN MOTION AROUND AXES OF CRANKSHAFTS 4 OR 5 MOTORS AXIS lighter nose ballast its replacing connecting rod plate could made thin plywood aluminum hard balsa nonessential parts cut away drilled lightening mechanism should work quite freely commercial units remember old days might called sloppy crank-to-conrod clearances Make cranks close identical possible Bending jig would best way crank bit longer throw could bind up whole machine unless got really sloppy tolerances Provision must made cut friction caused rearward pull motor Teflon washers might best way go using two motor cranks connecting rod between third crank must added system just idler just keep connecting rod supported three points will go over-center motor crank third crank could used propeller attachment Bruce feels method winding several motors simultaneously takes no longer wind normal motor setup main contribution reviving synchronized cranking gearless transmission Id say help popularizing concept pretty big contribution well words .if snub-nosed short-coupled beauty tuming you know shell need lead prop fly Warp Drive may answer elevating quality love life fascinated Warp Drive idea wish discuss its fervent proponent Bruce Holbrook write him 108 Maypoint Rd Apt 11 West Royalty PEI Canada CIE ff6 Until next time gang keep CC belongs never use rubber prop can handle ________[LC _____________ Ji ftRDC I L November1994 93 rubbersiotora~6lo otots7 tube bantboo Rear AnciorAssem6 fo 1& lfrfreAlotors