2 Later Vehigh-powen s free-flight o engui such Sc im-bronze--c s fuels co methane Axis Ice V alp level gthwise front Center Gr NO OCR TEXT g fl mount out WO d bY ddIO Ot l will tend r r rearward toWs e wing e down Convets forward C model wili farther re model will tend ton no attempt shOkld b d until th loc iodel irraVitY C inSi CO e plOP ft6 eClllC se po add r few r Gr el 1 Center stabilizer will make model nose up key point remember changing incidence stabilizer especi ally tilt used stabilizer glide turn remove shims under trailing edge also removes some turn add shims under leading edge also increases turn 3 Decalage Decalage angular difference between wing stabilizer greater angular difference the model will tend nose up Conversely less angular difference the model will tend nose down See Note 2 4 Engine down-thrust up-thrust Down- up-thrust viewed side angle formed thrust line centerline crankshaft arbitrary reference line thrust line points down angle negative causing nose go down thrust line points up angle positive causing nose go up 5 Engine power Engine power will cause model nose up power increased depending upon Center Gravity location Center Gravity too far back leading edge wing increased power will tend nose model down dive Center Gravity too far forward increased power will cause nose go up 6 Stabilizer airfoil section shape stabilizer similar wing airfoil stabilizer will also generate lift thickness airfoil shape airfoil determine lift characteristics As general rule stabilizer airfoil thick ness should less wing airfoil thickness 2 percent difference between example wing airfoil thickness 10 percent wing chord minimum thickness stabilizer airfoil should 8 percent stabilizer chord 7 Angle attack angle attack Fig 5 angle formed wing chord line line flight Therefore angle attack changing according wing attitude line flight angle attack determines amount lift follows lift also changing according change angle attack example angle attack increases lift increases until stall angle attack airfoil angle attack should confused angle incidence two angles have differ ent reference lines Namely line flight reference line angle attack constantly changing reference line angle incidence can arbitrary line angle built model 8 Pylon height thrust line position Lowering pylon height raising thrust-line position produce same effect reduce nose-up tendency during climb Raising pylon height lowering thrust-line position will tend increase nose up attitude 9 Stabilizerposition relation wing downwash Positioning stabilizer wing downwash will cause model nose up climb due downwash striking top surface stabilizer forcing stabilizer down nose up longer stabilizer moment arm distance wing less effective downwash becomes stabilizer reason smaller size stabilizer can used Vertical axis Fig 6 runs vertical top bottom passing through Center Gravity also called Directional Turn axis since model turns around axis either right left Factors will cause model turn right left 1 Vertical fin rudder tab offset Positioning vertical fin rudder tab off center centerline fuselage viewed top will cause model turn Offsetting trailing edge vertical fin rudder tab left fuselage centerline will turn model left As speed model increases effectiveness offset fin rudder tab increases Therefore flight testing make very small movements vertical fin rudder tab 1/32 flight piece trailing edge stock glued trailing edge Continued page 111 July 1979 37 Selection bubble protractors measure downthrust angle incidence wing stabilizer Reading clockwise left Surplus prop blade angle protractor Sears Protractor Level Sears Angle Finder precision protractor can used 12-in steel scale See text HOBBYPOXY FORMULA 3 THIXOTROPIC EPOXY GLUE NO SAGS. NORIJNS. NO DR PS. Formula 3 specially formulated gel-like viscosity allowing applied vertical surfaces thin edges other problem areas other glues just run off makes Formula 3 perfect planking building up reinforcing fillets joints sealing cracks filling holes joining poorly fitted badly die-crushed parts . hundred other things youve always wished kind glue now its made Hobbypoxy leader epoxy glues model building Formula 3 packaged two four-ounce cans has working time hour cures hard overnight mmmiv minuws L Division Pettit Paint co Inc 36 Pine Street Rockaway NJ 07866 RC Pylon/Hager continued page 28 28 West Coast race held Mile Square Park Fountain Valley CA hosted QMRC Vince Stag naro CD 17 fliers braved cold winds rain hail snow yes snow southern California sounds like Ohio Due weather four rounds flown Tom Christopher Bob Novak tied lead Tom took prize since fast time 1395 want keep readers informed what going racing throughout country Send us contest reports anything else would like share readers Bill Hager 5200 Rye Dr Dayton OH 45424 AMA Free Flight/Prey continued page 37 vertical fin makes excellent tab instead cutting fin Different thicknesses balsa wood can glued trailing edge stock increase turn wood can shaved off trailing edge stock decrease turn tab used turn adjustment no specific location shown plans locate tab near base trailing edge vertical fin Locating tab near top vertical fin will tend cause rolling effect around Longitu dinal axis well turn thereby achieve desired results 2 Right-or-left engine thrust Right- left-thrust viewed top angle formed line drawn lengthwise through center crankshaft measured either right left center line fuselage Cocking engine thrust line off center will cause model turn direction engine thrust line Engine thrust offset effective low speeds speed increased thrust offset becomes less effective rea son thrust offset used primarily control initial part climb vertical fin rudder tab offset used control remainder power climb Finally model must have stability Without stability around axis rota tion doomed self destruction Stability ability model resist changes normal flight also ability upset outside force such gust wind recover return normal flight designer model determined certain stability factors such dihedral angle size stabilizer vertical fin too must decide certain stability factors such angles incidence wing stabilizer amount rudder-tab offset engine-thrust offset etc have vital role eventual stability model about ready go flying well just Part Two Meanwhile spare moments become familiar checking decalage models using bubble protractor spirit level Use spirit level establish reference line convenience zero degrees bubble protractor measure angle incidence wing stabilizer angular difference tween decalage same measure down thrust Also experiment different thicknesses wood see much takes change angle incidence degree wing stabilizer dont have bubble protractor Sears has several inex pensive types available retail cata logue order example Angle Finder #93987 retails Los Angeles $399 Protractor Level #9-3990 retails $289 Either style excellent model use Also check hardware stores precision style bubble protractor dont overlook Army Surplus stores obsolete propeller blade angle protractor Lastly experiment shifting Cen ter Gravity models Use lead fish weights Any sporting store has fish weights sizes increments ounce ounces Dont forget check wing stabilizer wash-in wash out Armed new knowledge can honestly say ready go flying. see next month Note 1 Center Gravity thing physicists call resultant examJuly1979 111 r
Edition: Model Aviation - 1979/07
Page Numbers: 33, 34, 35, 36, 37, 111
2 Later Vehigh-powen s free-flight o engui such Sc im-bronze--c s fuels co methane Axis Ice V alp level gthwise front Center Gr NO OCR TEXT g fl mount out WO d bY ddIO Ot l will tend r r rearward toWs e wing e down Convets forward C model wili farther re model will tend ton no attempt shOkld b d until th loc iodel irraVitY C inSi CO e plOP ft6 eClllC se po add r few r Gr el 1 Center stabilizer will make model nose up key point remember changing incidence stabilizer especi ally tilt used stabilizer glide turn remove shims under trailing edge also removes some turn add shims under leading edge also increases turn 3 Decalage Decalage angular difference between wing stabilizer greater angular difference the model will tend nose up Conversely less angular difference the model will tend nose down See Note 2 4 Engine down-thrust up-thrust Down- up-thrust viewed side angle formed thrust line centerline crankshaft arbitrary reference line thrust line points down angle negative causing nose go down thrust line points up angle positive causing nose go up 5 Engine power Engine power will cause model nose up power increased depending upon Center Gravity location Center Gravity too far back leading edge wing increased power will tend nose model down dive Center Gravity too far forward increased power will cause nose go up 6 Stabilizer airfoil section shape stabilizer similar wing airfoil stabilizer will also generate lift thickness airfoil shape airfoil determine lift characteristics As general rule stabilizer airfoil thick ness should less wing airfoil thickness 2 percent difference between example wing airfoil thickness 10 percent wing chord minimum thickness stabilizer airfoil should 8 percent stabilizer chord 7 Angle attack angle attack Fig 5 angle formed wing chord line line flight Therefore angle attack changing according wing attitude line flight angle attack determines amount lift follows lift also changing according change angle attack example angle attack increases lift increases until stall angle attack airfoil angle attack should confused angle incidence two angles have differ ent reference lines Namely line flight reference line angle attack constantly changing reference line angle incidence can arbitrary line angle built model 8 Pylon height thrust line position Lowering pylon height raising thrust-line position produce same effect reduce nose-up tendency during climb Raising pylon height lowering thrust-line position will tend increase nose up attitude 9 Stabilizerposition relation wing downwash Positioning stabilizer wing downwash will cause model nose up climb due downwash striking top surface stabilizer forcing stabilizer down nose up longer stabilizer moment arm distance wing less effective downwash becomes stabilizer reason smaller size stabilizer can used Vertical axis Fig 6 runs vertical top bottom passing through Center Gravity also called Directional Turn axis since model turns around axis either right left Factors will cause model turn right left 1 Vertical fin rudder tab offset Positioning vertical fin rudder tab off center centerline fuselage viewed top will cause model turn Offsetting trailing edge vertical fin rudder tab left fuselage centerline will turn model left As speed model increases effectiveness offset fin rudder tab increases Therefore flight testing make very small movements vertical fin rudder tab 1/32 flight piece trailing edge stock glued trailing edge Continued page 111 July 1979 37 Selection bubble protractors measure downthrust angle incidence wing stabilizer Reading clockwise left Surplus prop blade angle protractor Sears Protractor Level Sears Angle Finder precision protractor can used 12-in steel scale See text HOBBYPOXY FORMULA 3 THIXOTROPIC EPOXY GLUE NO SAGS. NORIJNS. NO DR PS. Formula 3 specially formulated gel-like viscosity allowing applied vertical surfaces thin edges other problem areas other glues just run off makes Formula 3 perfect planking building up reinforcing fillets joints sealing cracks filling holes joining poorly fitted badly die-crushed parts . hundred other things youve always wished kind glue now its made Hobbypoxy leader epoxy glues model building Formula 3 packaged two four-ounce cans has working time hour cures hard overnight mmmiv minuws L Division Pettit Paint co Inc 36 Pine Street Rockaway NJ 07866 RC Pylon/Hager continued page 28 28 West Coast race held Mile Square Park Fountain Valley CA hosted QMRC Vince Stag naro CD 17 fliers braved cold winds rain hail snow yes snow southern California sounds like Ohio Due weather four rounds flown Tom Christopher Bob Novak tied lead Tom took prize since fast time 1395 want keep readers informed what going racing throughout country Send us contest reports anything else would like share readers Bill Hager 5200 Rye Dr Dayton OH 45424 AMA Free Flight/Prey continued page 37 vertical fin makes excellent tab instead cutting fin Different thicknesses balsa wood can glued trailing edge stock increase turn wood can shaved off trailing edge stock decrease turn tab used turn adjustment no specific location shown plans locate tab near base trailing edge vertical fin Locating tab near top vertical fin will tend cause rolling effect around Longitu dinal axis well turn thereby achieve desired results 2 Right-or-left engine thrust Right- left-thrust viewed top angle formed line drawn lengthwise through center crankshaft measured either right left center line fuselage Cocking engine thrust line off center will cause model turn direction engine thrust line Engine thrust offset effective low speeds speed increased thrust offset becomes less effective rea son thrust offset used primarily control initial part climb vertical fin rudder tab offset used control remainder power climb Finally model must have stability Without stability around axis rota tion doomed self destruction Stability ability model resist changes normal flight also ability upset outside force such gust wind recover return normal flight designer model determined certain stability factors such dihedral angle size stabilizer vertical fin too must decide certain stability factors such angles incidence wing stabilizer amount rudder-tab offset engine-thrust offset etc have vital role eventual stability model about ready go flying well just Part Two Meanwhile spare moments become familiar checking decalage models using bubble protractor spirit level Use spirit level establish reference line convenience zero degrees bubble protractor measure angle incidence wing stabilizer angular difference tween decalage same measure down thrust Also experiment different thicknesses wood see much takes change angle incidence degree wing stabilizer dont have bubble protractor Sears has several inex pensive types available retail cata logue order example Angle Finder #93987 retails Los Angeles $399 Protractor Level #9-3990 retails $289 Either style excellent model use Also check hardware stores precision style bubble protractor dont overlook Army Surplus stores obsolete propeller blade angle protractor Lastly experiment shifting Cen ter Gravity models Use lead fish weights Any sporting store has fish weights sizes increments ounce ounces Dont forget check wing stabilizer wash-in wash out Armed new knowledge can honestly say ready go flying. see next month Note 1 Center Gravity thing physicists call resultant examJuly1979 111 r
Edition: Model Aviation - 1979/07
Page Numbers: 33, 34, 35, 36, 37, 111
2 Later Vehigh-powen s free-flight o engui such Sc im-bronze--c s fuels co methane Axis Ice V alp level gthwise front Center Gr NO OCR TEXT g fl mount out WO d bY ddIO Ot l will tend r r rearward toWs e wing e down Convets forward C model wili farther re model will tend ton no attempt shOkld b d until th loc iodel irraVitY C inSi CO e plOP ft6 eClllC se po add r few r Gr el 1 Center stabilizer will make model nose up key point remember changing incidence stabilizer especi ally tilt used stabilizer glide turn remove shims under trailing edge also removes some turn add shims under leading edge also increases turn 3 Decalage Decalage angular difference between wing stabilizer greater angular difference the model will tend nose up Conversely less angular difference the model will tend nose down See Note 2 4 Engine down-thrust up-thrust Down- up-thrust viewed side angle formed thrust line centerline crankshaft arbitrary reference line thrust line points down angle negative causing nose go down thrust line points up angle positive causing nose go up 5 Engine power Engine power will cause model nose up power increased depending upon Center Gravity location Center Gravity too far back leading edge wing increased power will tend nose model down dive Center Gravity too far forward increased power will cause nose go up 6 Stabilizer airfoil section shape stabilizer similar wing airfoil stabilizer will also generate lift thickness airfoil shape airfoil determine lift characteristics As general rule stabilizer airfoil thick ness should less wing airfoil thickness 2 percent difference between example wing airfoil thickness 10 percent wing chord minimum thickness stabilizer airfoil should 8 percent stabilizer chord 7 Angle attack angle attack Fig 5 angle formed wing chord line line flight Therefore angle attack changing according wing attitude line flight angle attack determines amount lift follows lift also changing according change angle attack example angle attack increases lift increases until stall angle attack airfoil angle attack should confused angle incidence two angles have differ ent reference lines Namely line flight reference line angle attack constantly changing reference line angle incidence can arbitrary line angle built model 8 Pylon height thrust line position Lowering pylon height raising thrust-line position produce same effect reduce nose-up tendency during climb Raising pylon height lowering thrust-line position will tend increase nose up attitude 9 Stabilizerposition relation wing downwash Positioning stabilizer wing downwash will cause model nose up climb due downwash striking top surface stabilizer forcing stabilizer down nose up longer stabilizer moment arm distance wing less effective downwash becomes stabilizer reason smaller size stabilizer can used Vertical axis Fig 6 runs vertical top bottom passing through Center Gravity also called Directional Turn axis since model turns around axis either right left Factors will cause model turn right left 1 Vertical fin rudder tab offset Positioning vertical fin rudder tab off center centerline fuselage viewed top will cause model turn Offsetting trailing edge vertical fin rudder tab left fuselage centerline will turn model left As speed model increases effectiveness offset fin rudder tab increases Therefore flight testing make very small movements vertical fin rudder tab 1/32 flight piece trailing edge stock glued trailing edge Continued page 111 July 1979 37 Selection bubble protractors measure downthrust angle incidence wing stabilizer Reading clockwise left Surplus prop blade angle protractor Sears Protractor Level Sears Angle Finder precision protractor can used 12-in steel scale See text HOBBYPOXY FORMULA 3 THIXOTROPIC EPOXY GLUE NO SAGS. NORIJNS. NO DR PS. Formula 3 specially formulated gel-like viscosity allowing applied vertical surfaces thin edges other problem areas other glues just run off makes Formula 3 perfect planking building up reinforcing fillets joints sealing cracks filling holes joining poorly fitted badly die-crushed parts . hundred other things youve always wished kind glue now its made Hobbypoxy leader epoxy glues model building Formula 3 packaged two four-ounce cans has working time hour cures hard overnight mmmiv minuws L Division Pettit Paint co Inc 36 Pine Street Rockaway NJ 07866 RC Pylon/Hager continued page 28 28 West Coast race held Mile Square Park Fountain Valley CA hosted QMRC Vince Stag naro CD 17 fliers braved cold winds rain hail snow yes snow southern California sounds like Ohio Due weather four rounds flown Tom Christopher Bob Novak tied lead Tom took prize since fast time 1395 want keep readers informed what going racing throughout country Send us contest reports anything else would like share readers Bill Hager 5200 Rye Dr Dayton OH 45424 AMA Free Flight/Prey continued page 37 vertical fin makes excellent tab instead cutting fin Different thicknesses balsa wood can glued trailing edge stock increase turn wood can shaved off trailing edge stock decrease turn tab used turn adjustment no specific location shown plans locate tab near base trailing edge vertical fin Locating tab near top vertical fin will tend cause rolling effect around Longitu dinal axis well turn thereby achieve desired results 2 Right-or-left engine thrust Right- left-thrust viewed top angle formed line drawn lengthwise through center crankshaft measured either right left center line fuselage Cocking engine thrust line off center will cause model turn direction engine thrust line Engine thrust offset effective low speeds speed increased thrust offset becomes less effective rea son thrust offset used primarily control initial part climb vertical fin rudder tab offset used control remainder power climb Finally model must have stability Without stability around axis rota tion doomed self destruction Stability ability model resist changes normal flight also ability upset outside force such gust wind recover return normal flight designer model determined certain stability factors such dihedral angle size stabilizer vertical fin too must decide certain stability factors such angles incidence wing stabilizer amount rudder-tab offset engine-thrust offset etc have vital role eventual stability model about ready go flying well just Part Two Meanwhile spare moments become familiar checking decalage models using bubble protractor spirit level Use spirit level establish reference line convenience zero degrees bubble protractor measure angle incidence wing stabilizer angular difference tween decalage same measure down thrust Also experiment different thicknesses wood see much takes change angle incidence degree wing stabilizer dont have bubble protractor Sears has several inex pensive types available retail cata logue order example Angle Finder #93987 retails Los Angeles $399 Protractor Level #9-3990 retails $289 Either style excellent model use Also check hardware stores precision style bubble protractor dont overlook Army Surplus stores obsolete propeller blade angle protractor Lastly experiment shifting Cen ter Gravity models Use lead fish weights Any sporting store has fish weights sizes increments ounce ounces Dont forget check wing stabilizer wash-in wash out Armed new knowledge can honestly say ready go flying. see next month Note 1 Center Gravity thing physicists call resultant examJuly1979 111 r
Edition: Model Aviation - 1979/07
Page Numbers: 33, 34, 35, 36, 37, 111
2 Later Vehigh-powen s free-flight o engui such Sc im-bronze--c s fuels co methane Axis Ice V alp level gthwise front Center Gr NO OCR TEXT g fl mount out WO d bY ddIO Ot l will tend r r rearward toWs e wing e down Convets forward C model wili farther re model will tend ton no attempt shOkld b d until th loc iodel irraVitY C inSi CO e plOP ft6 eClllC se po add r few r Gr el 1 Center stabilizer will make model nose up key point remember changing incidence stabilizer especi ally tilt used stabilizer glide turn remove shims under trailing edge also removes some turn add shims under leading edge also increases turn 3 Decalage Decalage angular difference between wing stabilizer greater angular difference the model will tend nose up Conversely less angular difference the model will tend nose down See Note 2 4 Engine down-thrust up-thrust Down- up-thrust viewed side angle formed thrust line centerline crankshaft arbitrary reference line thrust line points down angle negative causing nose go down thrust line points up angle positive causing nose go up 5 Engine power Engine power will cause model nose up power increased depending upon Center Gravity location Center Gravity too far back leading edge wing increased power will tend nose model down dive Center Gravity too far forward increased power will cause nose go up 6 Stabilizer airfoil section shape stabilizer similar wing airfoil stabilizer will also generate lift thickness airfoil shape airfoil determine lift characteristics As general rule stabilizer airfoil thick ness should less wing airfoil thickness 2 percent difference between example wing airfoil thickness 10 percent wing chord minimum thickness stabilizer airfoil should 8 percent stabilizer chord 7 Angle attack angle attack Fig 5 angle formed wing chord line line flight Therefore angle attack changing according wing attitude line flight angle attack determines amount lift follows lift also changing according change angle attack example angle attack increases lift increases until stall angle attack airfoil angle attack should confused angle incidence two angles have differ ent reference lines Namely line flight reference line angle attack constantly changing reference line angle incidence can arbitrary line angle built model 8 Pylon height thrust line position Lowering pylon height raising thrust-line position produce same effect reduce nose-up tendency during climb Raising pylon height lowering thrust-line position will tend increase nose up attitude 9 Stabilizerposition relation wing downwash Positioning stabilizer wing downwash will cause model nose up climb due downwash striking top surface stabilizer forcing stabilizer down nose up longer stabilizer moment arm distance wing less effective downwash becomes stabilizer reason smaller size stabilizer can used Vertical axis Fig 6 runs vertical top bottom passing through Center Gravity also called Directional Turn axis since model turns around axis either right left Factors will cause model turn right left 1 Vertical fin rudder tab offset Positioning vertical fin rudder tab off center centerline fuselage viewed top will cause model turn Offsetting trailing edge vertical fin rudder tab left fuselage centerline will turn model left As speed model increases effectiveness offset fin rudder tab increases Therefore flight testing make very small movements vertical fin rudder tab 1/32 flight piece trailing edge stock glued trailing edge Continued page 111 July 1979 37 Selection bubble protractors measure downthrust angle incidence wing stabilizer Reading clockwise left Surplus prop blade angle protractor Sears Protractor Level Sears Angle Finder precision protractor can used 12-in steel scale See text HOBBYPOXY FORMULA 3 THIXOTROPIC EPOXY GLUE NO SAGS. NORIJNS. NO DR PS. Formula 3 specially formulated gel-like viscosity allowing applied vertical surfaces thin edges other problem areas other glues just run off makes Formula 3 perfect planking building up reinforcing fillets joints sealing cracks filling holes joining poorly fitted badly die-crushed parts . hundred other things youve always wished kind glue now its made Hobbypoxy leader epoxy glues model building Formula 3 packaged two four-ounce cans has working time hour cures hard overnight mmmiv minuws L Division Pettit Paint co Inc 36 Pine Street Rockaway NJ 07866 RC Pylon/Hager continued page 28 28 West Coast race held Mile Square Park Fountain Valley CA hosted QMRC Vince Stag naro CD 17 fliers braved cold winds rain hail snow yes snow southern California sounds like Ohio Due weather four rounds flown Tom Christopher Bob Novak tied lead Tom took prize since fast time 1395 want keep readers informed what going racing throughout country Send us contest reports anything else would like share readers Bill Hager 5200 Rye Dr Dayton OH 45424 AMA Free Flight/Prey continued page 37 vertical fin makes excellent tab instead cutting fin Different thicknesses balsa wood can glued trailing edge stock increase turn wood can shaved off trailing edge stock decrease turn tab used turn adjustment no specific location shown plans locate tab near base trailing edge vertical fin Locating tab near top vertical fin will tend cause rolling effect around Longitu dinal axis well turn thereby achieve desired results 2 Right-or-left engine thrust Right- left-thrust viewed top angle formed line drawn lengthwise through center crankshaft measured either right left center line fuselage Cocking engine thrust line off center will cause model turn direction engine thrust line Engine thrust offset effective low speeds speed increased thrust offset becomes less effective rea son thrust offset used primarily control initial part climb vertical fin rudder tab offset used control remainder power climb Finally model must have stability Without stability around axis rota tion doomed self destruction Stability ability model resist changes normal flight also ability upset outside force such gust wind recover return normal flight designer model determined certain stability factors such dihedral angle size stabilizer vertical fin too must decide certain stability factors such angles incidence wing stabilizer amount rudder-tab offset engine-thrust offset etc have vital role eventual stability model about ready go flying well just Part Two Meanwhile spare moments become familiar checking decalage models using bubble protractor spirit level Use spirit level establish reference line convenience zero degrees bubble protractor measure angle incidence wing stabilizer angular difference tween decalage same measure down thrust Also experiment different thicknesses wood see much takes change angle incidence degree wing stabilizer dont have bubble protractor Sears has several inex pensive types available retail cata logue order example Angle Finder #93987 retails Los Angeles $399 Protractor Level #9-3990 retails $289 Either style excellent model use Also check hardware stores precision style bubble protractor dont overlook Army Surplus stores obsolete propeller blade angle protractor Lastly experiment shifting Cen ter Gravity models Use lead fish weights Any sporting store has fish weights sizes increments ounce ounces Dont forget check wing stabilizer wash-in wash out Armed new knowledge can honestly say ready go flying. see next month Note 1 Center Gravity thing physicists call resultant examJuly1979 111 r
Edition: Model Aviation - 1979/07
Page Numbers: 33, 34, 35, 36, 37, 111
2 Later Vehigh-powen s free-flight o engui such Sc im-bronze--c s fuels co methane Axis Ice V alp level gthwise front Center Gr NO OCR TEXT g fl mount out WO d bY ddIO Ot l will tend r r rearward toWs e wing e down Convets forward C model wili farther re model will tend ton no attempt shOkld b d until th loc iodel irraVitY C inSi CO e plOP ft6 eClllC se po add r few r Gr el 1 Center stabilizer will make model nose up key point remember changing incidence stabilizer especi ally tilt used stabilizer glide turn remove shims under trailing edge also removes some turn add shims under leading edge also increases turn 3 Decalage Decalage angular difference between wing stabilizer greater angular difference the model will tend nose up Conversely less angular difference the model will tend nose down See Note 2 4 Engine down-thrust up-thrust Down- up-thrust viewed side angle formed thrust line centerline crankshaft arbitrary reference line thrust line points down angle negative causing nose go down thrust line points up angle positive causing nose go up 5 Engine power Engine power will cause model nose up power increased depending upon Center Gravity location Center Gravity too far back leading edge wing increased power will tend nose model down dive Center Gravity too far forward increased power will cause nose go up 6 Stabilizer airfoil section shape stabilizer similar wing airfoil stabilizer will also generate lift thickness airfoil shape airfoil determine lift characteristics As general rule stabilizer airfoil thick ness should less wing airfoil thickness 2 percent difference between example wing airfoil thickness 10 percent wing chord minimum thickness stabilizer airfoil should 8 percent stabilizer chord 7 Angle attack angle attack Fig 5 angle formed wing chord line line flight Therefore angle attack changing according wing attitude line flight angle attack determines amount lift follows lift also changing according change angle attack example angle attack increases lift increases until stall angle attack airfoil angle attack should confused angle incidence two angles have differ ent reference lines Namely line flight reference line angle attack constantly changing reference line angle incidence can arbitrary line angle built model 8 Pylon height thrust line position Lowering pylon height raising thrust-line position produce same effect reduce nose-up tendency during climb Raising pylon height lowering thrust-line position will tend increase nose up attitude 9 Stabilizerposition relation wing downwash Positioning stabilizer wing downwash will cause model nose up climb due downwash striking top surface stabilizer forcing stabilizer down nose up longer stabilizer moment arm distance wing less effective downwash becomes stabilizer reason smaller size stabilizer can used Vertical axis Fig 6 runs vertical top bottom passing through Center Gravity also called Directional Turn axis since model turns around axis either right left Factors will cause model turn right left 1 Vertical fin rudder tab offset Positioning vertical fin rudder tab off center centerline fuselage viewed top will cause model turn Offsetting trailing edge vertical fin rudder tab left fuselage centerline will turn model left As speed model increases effectiveness offset fin rudder tab increases Therefore flight testing make very small movements vertical fin rudder tab 1/32 flight piece trailing edge stock glued trailing edge Continued page 111 July 1979 37 Selection bubble protractors measure downthrust angle incidence wing stabilizer Reading clockwise left Surplus prop blade angle protractor Sears Protractor Level Sears Angle Finder precision protractor can used 12-in steel scale See text HOBBYPOXY FORMULA 3 THIXOTROPIC EPOXY GLUE NO SAGS. NORIJNS. NO DR PS. Formula 3 specially formulated gel-like viscosity allowing applied vertical surfaces thin edges other problem areas other glues just run off makes Formula 3 perfect planking building up reinforcing fillets joints sealing cracks filling holes joining poorly fitted badly die-crushed parts . hundred other things youve always wished kind glue now its made Hobbypoxy leader epoxy glues model building Formula 3 packaged two four-ounce cans has working time hour cures hard overnight mmmiv minuws L Division Pettit Paint co Inc 36 Pine Street Rockaway NJ 07866 RC Pylon/Hager continued page 28 28 West Coast race held Mile Square Park Fountain Valley CA hosted QMRC Vince Stag naro CD 17 fliers braved cold winds rain hail snow yes snow southern California sounds like Ohio Due weather four rounds flown Tom Christopher Bob Novak tied lead Tom took prize since fast time 1395 want keep readers informed what going racing throughout country Send us contest reports anything else would like share readers Bill Hager 5200 Rye Dr Dayton OH 45424 AMA Free Flight/Prey continued page 37 vertical fin makes excellent tab instead cutting fin Different thicknesses balsa wood can glued trailing edge stock increase turn wood can shaved off trailing edge stock decrease turn tab used turn adjustment no specific location shown plans locate tab near base trailing edge vertical fin Locating tab near top vertical fin will tend cause rolling effect around Longitu dinal axis well turn thereby achieve desired results 2 Right-or-left engine thrust Right- left-thrust viewed top angle formed line drawn lengthwise through center crankshaft measured either right left center line fuselage Cocking engine thrust line off center will cause model turn direction engine thrust line Engine thrust offset effective low speeds speed increased thrust offset becomes less effective rea son thrust offset used primarily control initial part climb vertical fin rudder tab offset used control remainder power climb Finally model must have stability Without stability around axis rota tion doomed self destruction Stability ability model resist changes normal flight also ability upset outside force such gust wind recover return normal flight designer model determined certain stability factors such dihedral angle size stabilizer vertical fin too must decide certain stability factors such angles incidence wing stabilizer amount rudder-tab offset engine-thrust offset etc have vital role eventual stability model about ready go flying well just Part Two Meanwhile spare moments become familiar checking decalage models using bubble protractor spirit level Use spirit level establish reference line convenience zero degrees bubble protractor measure angle incidence wing stabilizer angular difference tween decalage same measure down thrust Also experiment different thicknesses wood see much takes change angle incidence degree wing stabilizer dont have bubble protractor Sears has several inex pensive types available retail cata logue order example Angle Finder #93987 retails Los Angeles $399 Protractor Level #9-3990 retails $289 Either style excellent model use Also check hardware stores precision style bubble protractor dont overlook Army Surplus stores obsolete propeller blade angle protractor Lastly experiment shifting Cen ter Gravity models Use lead fish weights Any sporting store has fish weights sizes increments ounce ounces Dont forget check wing stabilizer wash-in wash out Armed new knowledge can honestly say ready go flying. see next month Note 1 Center Gravity thing physicists call resultant examJuly1979 111 r
Edition: Model Aviation - 1979/07
Page Numbers: 33, 34, 35, 36, 37, 111
2 Later Vehigh-powen s free-flight o engui such Sc im-bronze--c s fuels co methane Axis Ice V alp level gthwise front Center Gr NO OCR TEXT g fl mount out WO d bY ddIO Ot l will tend r r rearward toWs e wing e down Convets forward C model wili farther re model will tend ton no attempt shOkld b d until th loc iodel irraVitY C inSi CO e plOP ft6 eClllC se po add r few r Gr el 1 Center stabilizer will make model nose up key point remember changing incidence stabilizer especi ally tilt used stabilizer glide turn remove shims under trailing edge also removes some turn add shims under leading edge also increases turn 3 Decalage Decalage angular difference between wing stabilizer greater angular difference the model will tend nose up Conversely less angular difference the model will tend nose down See Note 2 4 Engine down-thrust up-thrust Down- up-thrust viewed side angle formed thrust line centerline crankshaft arbitrary reference line thrust line points down angle negative causing nose go down thrust line points up angle positive causing nose go up 5 Engine power Engine power will cause model nose up power increased depending upon Center Gravity location Center Gravity too far back leading edge wing increased power will tend nose model down dive Center Gravity too far forward increased power will cause nose go up 6 Stabilizer airfoil section shape stabilizer similar wing airfoil stabilizer will also generate lift thickness airfoil shape airfoil determine lift characteristics As general rule stabilizer airfoil thick ness should less wing airfoil thickness 2 percent difference between example wing airfoil thickness 10 percent wing chord minimum thickness stabilizer airfoil should 8 percent stabilizer chord 7 Angle attack angle attack Fig 5 angle formed wing chord line line flight Therefore angle attack changing according wing attitude line flight angle attack determines amount lift follows lift also changing according change angle attack example angle attack increases lift increases until stall angle attack airfoil angle attack should confused angle incidence two angles have differ ent reference lines Namely line flight reference line angle attack constantly changing reference line angle incidence can arbitrary line angle built model 8 Pylon height thrust line position Lowering pylon height raising thrust-line position produce same effect reduce nose-up tendency during climb Raising pylon height lowering thrust-line position will tend increase nose up attitude 9 Stabilizerposition relation wing downwash Positioning stabilizer wing downwash will cause model nose up climb due downwash striking top surface stabilizer forcing stabilizer down nose up longer stabilizer moment arm distance wing less effective downwash becomes stabilizer reason smaller size stabilizer can used Vertical axis Fig 6 runs vertical top bottom passing through Center Gravity also called Directional Turn axis since model turns around axis either right left Factors will cause model turn right left 1 Vertical fin rudder tab offset Positioning vertical fin rudder tab off center centerline fuselage viewed top will cause model turn Offsetting trailing edge vertical fin rudder tab left fuselage centerline will turn model left As speed model increases effectiveness offset fin rudder tab increases Therefore flight testing make very small movements vertical fin rudder tab 1/32 flight piece trailing edge stock glued trailing edge Continued page 111 July 1979 37 Selection bubble protractors measure downthrust angle incidence wing stabilizer Reading clockwise left Surplus prop blade angle protractor Sears Protractor Level Sears Angle Finder precision protractor can used 12-in steel scale See text HOBBYPOXY FORMULA 3 THIXOTROPIC EPOXY GLUE NO SAGS. NORIJNS. NO DR PS. Formula 3 specially formulated gel-like viscosity allowing applied vertical surfaces thin edges other problem areas other glues just run off makes Formula 3 perfect planking building up reinforcing fillets joints sealing cracks filling holes joining poorly fitted badly die-crushed parts . hundred other things youve always wished kind glue now its made Hobbypoxy leader epoxy glues model building Formula 3 packaged two four-ounce cans has working time hour cures hard overnight mmmiv minuws L Division Pettit Paint co Inc 36 Pine Street Rockaway NJ 07866 RC Pylon/Hager continued page 28 28 West Coast race held Mile Square Park Fountain Valley CA hosted QMRC Vince Stag naro CD 17 fliers braved cold winds rain hail snow yes snow southern California sounds like Ohio Due weather four rounds flown Tom Christopher Bob Novak tied lead Tom took prize since fast time 1395 want keep readers informed what going racing throughout country Send us contest reports anything else would like share readers Bill Hager 5200 Rye Dr Dayton OH 45424 AMA Free Flight/Prey continued page 37 vertical fin makes excellent tab instead cutting fin Different thicknesses balsa wood can glued trailing edge stock increase turn wood can shaved off trailing edge stock decrease turn tab used turn adjustment no specific location shown plans locate tab near base trailing edge vertical fin Locating tab near top vertical fin will tend cause rolling effect around Longitu dinal axis well turn thereby achieve desired results 2 Right-or-left engine thrust Right- left-thrust viewed top angle formed line drawn lengthwise through center crankshaft measured either right left center line fuselage Cocking engine thrust line off center will cause model turn direction engine thrust line Engine thrust offset effective low speeds speed increased thrust offset becomes less effective rea son thrust offset used primarily control initial part climb vertical fin rudder tab offset used control remainder power climb Finally model must have stability Without stability around axis rota tion doomed self destruction Stability ability model resist changes normal flight also ability upset outside force such gust wind recover return normal flight designer model determined certain stability factors such dihedral angle size stabilizer vertical fin too must decide certain stability factors such angles incidence wing stabilizer amount rudder-tab offset engine-thrust offset etc have vital role eventual stability model about ready go flying well just Part Two Meanwhile spare moments become familiar checking decalage models using bubble protractor spirit level Use spirit level establish reference line convenience zero degrees bubble protractor measure angle incidence wing stabilizer angular difference tween decalage same measure down thrust Also experiment different thicknesses wood see much takes change angle incidence degree wing stabilizer dont have bubble protractor Sears has several inex pensive types available retail cata logue order example Angle Finder #93987 retails Los Angeles $399 Protractor Level #9-3990 retails $289 Either style excellent model use Also check hardware stores precision style bubble protractor dont overlook Army Surplus stores obsolete propeller blade angle protractor Lastly experiment shifting Cen ter Gravity models Use lead fish weights Any sporting store has fish weights sizes increments ounce ounces Dont forget check wing stabilizer wash-in wash out Armed new knowledge can honestly say ready go flying. see next month Note 1 Center Gravity thing physicists call resultant examJuly1979 111 r