CONTROL LINE SPEED Santiago Rodriguez Garrido Madrid Spain sent report about 1996 F2A Speed world champion Luis Parramon model Spaniards very proud Luis title Santiagos correspondence gives complete explanation of work done airplane design engine rework tuned-pipe analysis propellers no secrets involved just hard work part system want compete win world competition must work hard have very little time anything else Most people US modelers arent aware such thing international competition contrast modeling champion foreign countries has same status Olympic athlete national hero World Championship competition held holiday declared peopleespecially young people can see flying countries sponsor modelers provide materials supplies training think international competition started 1930s rubber-powered Free Flight FF Wakefield first events probably still prestigious real modelers Control Line CL Speed got started after World War II mid-1950s various countries hosting European CL Championships Speed first events Team Race Precision Aerobatics also flown Since aeronautics involved FAI Federation Aeronautique Internationale got involved Europeans formed Committee International Aero Modeling ClAM Im writing memory dont get excited get little mixed up first Americans compete CL US servicemen stationed Europe After AMA got enough members money sponsor US teams Official international competition started FF contest year CL contest next year FF events Wakefield Towline Glider FAt Power CL Speed Team Race Aerobatics Events have expanded greatly since several Radio Control events Scale Pylon dont forget Indoor CL Speed really got started around 1958 Bill Wisniewski experimenting building 25 cc engines world champion several times Italian Superigre engines very good Hungarian Czech engines Russian modelers sponsored state got going became very good Speed Team Race developed engines such Kojaniuk Cyclon Shelkalin Zalp others difficult other modelers obtain engines except trading 1992 Perestroika breakup Soviet states changed policies Russians others began mass-producing engines selling westerners Luis Parramon has flying Speed 20 years has held Spanish record several times used Rossi engines until 1990 getting speeds up 280 km/h 175 mph obtained 134 Model Aviation friends tested models wind tunnel Barcelona Engineering School wind velocities high 200 kmih possible Luis Parramon Spain poses winning model Barcelona 96 world champion trophies certificates Engines tested dynamometer GP Development lab power torque pressures temperatures various rpm high 38000 measured Cyclon engine 1992 broke Spanish record 291 km/h 182 mph Barcelona 1993 purchased Profi engine turned 299 km/h 187 mph 1994 Luiss next challenge attain 300 km/h worked friends Lluis Roger Jaume Porta Jordi Fout Eduard Giro obtained information books such Two Stroke Performance Tuning Graham Bell Motorcycle Tuning Two Stroke Engines John Robinson especially Design Simulation Two Stroke Engines Gordon Blair sources Luis used computing programs thermodynamic simulations other programs Lluis Roger propeller design model design CL cable flying wire leading addition mathematical calculations tested models wind tunnel Salvador Gonzalez Barcelona Engineering School tested engines dyno bench GP Development measured power torque versus rpm head exhaust temperatures exhaust head crankcase pressures transducers also ran metallographic analysis surface treatment analysis Luiss sidewinder airplane has traditional metal pan long almost onemeter aluminum inner wing does use wood fiberglass carbon fiber body tail used extruded polymethacrylate foam called Rohacell unaffected vibration comes various densities 35 kg/m3 foam used stab 50 kg/m3 used tailboom body wing has symmetrical airfoil tip swept back front flying wire 26 mm behind Center Gravity CG line rake compensates wire drag allows model fly tangent circle minimum drag model weighed 420 g engine pipe being 205 g Profi engine manufactured Ukraine powerful Speed engines available rather typical frontintake rear-exhaust ABC type couple interesting internal modifications has two ball bearings crankshaft engines rear doesnt have internal race balls run groove ground crankshaft ball retainer external race complete bearing Im interpreting letter correctly sleeve chrome-plated beryllium copper piston typical 24% silicon aluminum alloy Luis made few other modifications such changing valve timing 2300 boring crank 9 mm ID boring venturi 95 mm modifying transfer ports making head hemispherical chamber great deal work put crankshaft ball bearing assembly achieve perfect lowfriction fit 05 mm axial clearance front bearing Luiss propeller carbon-fiber-andresin single-blade also obtained Ukraine 742 mm radius 64 inches pitch dimensions metric except propeller pitch have no idea could because past winners have used inches top speed tip velocity approximately 1067 km/h 667 mph Mach 87 prop modified dimensions simulations computing program made Lluis Roger World Championships held July 22-29 1996 Swedish town Norrkoping unused airbase After some problems officials first flight Luis turned speed 304 km/h second flight became world champion third flight 3112 km/h 1945 mph hope has given some idea what takes world champion just difficult class since flying against best modelers world 4CL AerobaticslMcMillan Continued page 132 longer wings can exert However long-wing models fly well once trim Its easier set wings level lower aspect ratio designs seem less reactive turbulence Youve got model up air safely engine mnning reliably wing seems reasonably level outside circle appears riding inboard-wing-low adjustment time observe looking slight adjustment dont tweak things yet small increase tip weight might thing required case Depending design some models very sensitive tip weight add some point want reaction try half-ounce weight fly again close preflight settings will get you need condition looking should have equalright side up invertedif tmly tip weight added weight did level wingsor went past neutral opposite conditionand same nght side up inverted did have pure tip-weight problem adding tip weight exacerbated problem direction hurt other primarily flap tweak problem Cut back about half added weight wing went inboard-low slightly inboard-high soon wing still tends inboard-low after adding still weight need consider flap tweak tab Right now preference would tweak flaps times adjustment fraught chasing-the-tail syndrometoo much time too little next An adjustable tab part flap area very nice feature have can try go back-and-forth until have arrived good setting destroying best imtial alignment indication consider flap tweak/tab adjustment roll inside control opposite roll other control instance situation discussed previously inboard low upright up control would cause airplane roll down control would cause roll outside Make adjustment small increments case slight inboard flap down tab outboard wing tab up Fly again observe adjustment should start see airplanes reactions become linear rolling diminish Continue until wings level observed outside circle point can start looking tip weight see wing moving hard corner some have called hinging Think excess weight enough energy carry tip established line rather smoothly executing commanded tarn some models especially really light built-up wing designs tip weight overall will less will differential weight affects hinging Typically Ive seen about /2-ounce final tip weight little gram two showing hinging point lines diameter length type have signfi cant effect final trim Again leveling wings extremely important Dont hurry shotgun bunch changes until get right some other factors affect rolling after have achieved wings level Differential area flaps comes mind still heatedly argued day currently successful designs use slightly wider flap /32 inch outboard tip Its good number know works Others use tabs added outboard flap make adjustment thats another column Ive some good feedback previous column regarding effects pitch stability hard corners Well-known Nationals competitor Windy Urtnowski wrote thought last columnengine unloading higher rpm added GP stability lower pitchthis phenomenon especially true Big Jim setup using cut down 14 x 5 rev-ups pronounced 4-B carbon blades lower pitch rpmlots GP stabilityIve found true time go direction ie 6 pitch 55 4 etc assuming weight prop same Alsoa slightly higher comp will same thing rpmgood thoughts thanks detailing outmay help some guys understand whats happening out nose ember 1998 135
Edition: Model Aviation - 1998/09
Page Numbers: 134, 135
Edition: Model Aviation - 1998/09
Page Numbers: 134, 135
CONTROL LINE SPEED Santiago Rodriguez Garrido Madrid Spain sent report about 1996 F2A Speed world champion Luis Parramon model Spaniards very proud Luis title Santiagos correspondence gives complete explanation of work done airplane design engine rework tuned-pipe analysis propellers no secrets involved just hard work part system want compete win world competition must work hard have very little time anything else Most people US modelers arent aware such thing international competition contrast modeling champion foreign countries has same status Olympic athlete national hero World Championship competition held holiday declared peopleespecially young people can see flying countries sponsor modelers provide materials supplies training think international competition started 1930s rubber-powered Free Flight FF Wakefield first events probably still prestigious real modelers Control Line CL Speed got started after World War II mid-1950s various countries hosting European CL Championships Speed first events Team Race Precision Aerobatics also flown Since aeronautics involved FAI Federation Aeronautique Internationale got involved Europeans formed Committee International Aero Modeling ClAM Im writing memory dont get excited get little mixed up first Americans compete CL US servicemen stationed Europe After AMA got enough members money sponsor US teams Official international competition started FF contest year CL contest next year FF events Wakefield Towline Glider FAt Power CL Speed Team Race Aerobatics Events have expanded greatly since several Radio Control events Scale Pylon dont forget Indoor CL Speed really got started around 1958 Bill Wisniewski experimenting building 25 cc engines world champion several times Italian Superigre engines very good Hungarian Czech engines Russian modelers sponsored state got going became very good Speed Team Race developed engines such Kojaniuk Cyclon Shelkalin Zalp others difficult other modelers obtain engines except trading 1992 Perestroika breakup Soviet states changed policies Russians others began mass-producing engines selling westerners Luis Parramon has flying Speed 20 years has held Spanish record several times used Rossi engines until 1990 getting speeds up 280 km/h 175 mph obtained 134 Model Aviation friends tested models wind tunnel Barcelona Engineering School wind velocities high 200 kmih possible Luis Parramon Spain poses winning model Barcelona 96 world champion trophies certificates Engines tested dynamometer GP Development lab power torque pressures temperatures various rpm high 38000 measured Cyclon engine 1992 broke Spanish record 291 km/h 182 mph Barcelona 1993 purchased Profi engine turned 299 km/h 187 mph 1994 Luiss next challenge attain 300 km/h worked friends Lluis Roger Jaume Porta Jordi Fout Eduard Giro obtained information books such Two Stroke Performance Tuning Graham Bell Motorcycle Tuning Two Stroke Engines John Robinson especially Design Simulation Two Stroke Engines Gordon Blair sources Luis used computing programs thermodynamic simulations other programs Lluis Roger propeller design model design CL cable flying wire leading addition mathematical calculations tested models wind tunnel Salvador Gonzalez Barcelona Engineering School tested engines dyno bench GP Development measured power torque versus rpm head exhaust temperatures exhaust head crankcase pressures transducers also ran metallographic analysis surface treatment analysis Luiss sidewinder airplane has traditional metal pan long almost onemeter aluminum inner wing does use wood fiberglass carbon fiber body tail used extruded polymethacrylate foam called Rohacell unaffected vibration comes various densities 35 kg/m3 foam used stab 50 kg/m3 used tailboom body wing has symmetrical airfoil tip swept back front flying wire 26 mm behind Center Gravity CG line rake compensates wire drag allows model fly tangent circle minimum drag model weighed 420 g engine pipe being 205 g Profi engine manufactured Ukraine powerful Speed engines available rather typical frontintake rear-exhaust ABC type couple interesting internal modifications has two ball bearings crankshaft engines rear doesnt have internal race balls run groove ground crankshaft ball retainer external race complete bearing Im interpreting letter correctly sleeve chrome-plated beryllium copper piston typical 24% silicon aluminum alloy Luis made few other modifications such changing valve timing 2300 boring crank 9 mm ID boring venturi 95 mm modifying transfer ports making head hemispherical chamber great deal work put crankshaft ball bearing assembly achieve perfect lowfriction fit 05 mm axial clearance front bearing Luiss propeller carbon-fiber-andresin single-blade also obtained Ukraine 742 mm radius 64 inches pitch dimensions metric except propeller pitch have no idea could because past winners have used inches top speed tip velocity approximately 1067 km/h 667 mph Mach 87 prop modified dimensions simulations computing program made Lluis Roger World Championships held July 22-29 1996 Swedish town Norrkoping unused airbase After some problems officials first flight Luis turned speed 304 km/h second flight became world champion third flight 3112 km/h 1945 mph hope has given some idea what takes world champion just difficult class since flying against best modelers world 4CL AerobaticslMcMillan Continued page 132 longer wings can exert However long-wing models fly well once trim Its easier set wings level lower aspect ratio designs seem less reactive turbulence Youve got model up air safely engine mnning reliably wing seems reasonably level outside circle appears riding inboard-wing-low adjustment time observe looking slight adjustment dont tweak things yet small increase tip weight might thing required case Depending design some models very sensitive tip weight add some point want reaction try half-ounce weight fly again close preflight settings will get you need condition looking should have equalright side up invertedif tmly tip weight added weight did level wingsor went past neutral opposite conditionand same nght side up inverted did have pure tip-weight problem adding tip weight exacerbated problem direction hurt other primarily flap tweak problem Cut back about half added weight wing went inboard-low slightly inboard-high soon wing still tends inboard-low after adding still weight need consider flap tweak tab Right now preference would tweak flaps times adjustment fraught chasing-the-tail syndrometoo much time too little next An adjustable tab part flap area very nice feature have can try go back-and-forth until have arrived good setting destroying best imtial alignment indication consider flap tweak/tab adjustment roll inside control opposite roll other control instance situation discussed previously inboard low upright up control would cause airplane roll down control would cause roll outside Make adjustment small increments case slight inboard flap down tab outboard wing tab up Fly again observe adjustment should start see airplanes reactions become linear rolling diminish Continue until wings level observed outside circle point can start looking tip weight see wing moving hard corner some have called hinging Think excess weight enough energy carry tip established line rather smoothly executing commanded tarn some models especially really light built-up wing designs tip weight overall will less will differential weight affects hinging Typically Ive seen about /2-ounce final tip weight little gram two showing hinging point lines diameter length type have signfi cant effect final trim Again leveling wings extremely important Dont hurry shotgun bunch changes until get right some other factors affect rolling after have achieved wings level Differential area flaps comes mind still heatedly argued day currently successful designs use slightly wider flap /32 inch outboard tip Its good number know works Others use tabs added outboard flap make adjustment thats another column Ive some good feedback previous column regarding effects pitch stability hard corners Well-known Nationals competitor Windy Urtnowski wrote thought last columnengine unloading higher rpm added GP stability lower pitchthis phenomenon especially true Big Jim setup using cut down 14 x 5 rev-ups pronounced 4-B carbon blades lower pitch rpmlots GP stabilityIve found true time go direction ie 6 pitch 55 4 etc assuming weight prop same Alsoa slightly higher comp will same thing rpmgood thoughts thanks detailing outmay help some guys understand whats happening out nose ember 1998 135
