Balancing for Roll on CL Stunt Ships

Chris Lella Balancing Roll Some valuable tips will make model fly better inverted during maneuvers .L Stunt S1iis both level flight upright WHEN GETTING discussions about various characteristics ships modelers find peo ple have hard time expressing selves Also fliers have vague ideas lack understanding planes fly way build certain way think reason because modeling complete universal language due certain unfamiliarity aero nauticsboth terms physics ever does have mathema tical whiz become acquainted laws terms flight As matter fact cases mere ability add subtract multiply divide necessary make world aeronautics much intelligible modeling what presently Anyone knows anything some people advance quicker others sometimes difference really ex treme Some fliers send 20 ships before can two maneuvers Others learn Stunt Pattern year find can jus pattern perfecting average competitive level others win Nationals takes ten 20 years hangups anyone has levels cannot pointed out too specifically requirements nec essary anyone advance modeling can Putting psychological reasons aside three basic requirements IFlying ability itself eye-hand coordi nation 2Building skills carpentry finishing etc 3The basic knowledge about thing person building flying third usually overlooked taken granted because cant touch hands like can ship controls themselves also because lot usually taken care kitted plans Some modelers build near perfec tion also can sometimes build ship perfectly wrong also take year find out what could have learned week because whimsical theories fly quicker ships themselves flying field particular aspect may discussed can have ten interpretations Some novice may hear spend year trying abstract best possibly find out wrong builders put big efforts trial-and-error method discovery fine advanced modeler because ideas likely new unique part ex perts ideas have roots what already May1976 31 first-line Stunt ships appearing minor variations theme Fokker E-1 typeits scale model genuine eye-catcher also has coupled flaps elevatorswhich par coursebut may set RC Stik types thinking See Shark article page 35 Astra 77 entered Ed Prohaska 15 Nats modified Formuls Sa Jim Kostecky design Finish markings remarkable Fox 40 Balancing Roll knows However anyone less expert trial error can probably will complete waste time true two reasons times what trying has already proven right wrong research results instead wasting time money experimenting other rea son well-rounded knowl edge modeling strong basic knowl edge aeronautics too variables unknown experi ments unknown variables chance coming up undesired result also chance coming up no result Given opportunity would like explain balance situation CL stunt ships probably significant aspect concerns us minia ture air machines fly Because using some aeronautical terms physics hope broaden basic knowl edge have just speaking some fliers will in-depth physical analyses just abstractions basic ex planations what required modelMOMENT LONGITUDINAL MOMENTPITCH LATERAL AXIS 1_____ t PRESSURE ing particularly CL stunt flying So fore word physics should scare anyone Its like maintaining ones own car person can understand automobiles efficiently maintain own car out being automotive engineer order three part series will Balancing Roll Yaw Pitch chose order respect intelligibil ity think Roll easiest understand Pitch hardest However dont confuse simplicity trimming respect Pitch easiest Roll hardest Balancing Roll best way start explaining exactly what plane may sound little too basic see leads us youll understand plane vehicle requires three dimensional control Id like elaborate three dimensions make unique vehicle Think simpler vehicles first train instance simplest vehicle cause its directional control always con stant Only its speed directly controlled Any right left lateral up down vertical movement determined fixed rail car little com plex vertical movement fixed road driver controls speed also right left directions un like train Now know plane can move freely up down must controlled way However addition movement vertically makes air vehi cle complex because allows roll Therefore controlled around three dimensional axes unlike car controlled around train controlled around Now think planes three axes axis goes through fuselage longitudinal axis movement around axis called Roll See Fig axis goes vertically through fuselage vertical axis movement around axis called Yaw See Fig 2 axis goes laterally through wingspan lateral axis movement around axis called Pitch See Fig 3 Obviously CL flying control directly planes pitch roll yaw should held constant ever have good flying plane particu larly stuntship roll yaw must held ideal constant other words ship must properly balanced ship can must balanced two ways static balance use weights other aerodynamic balance An example aerodynamic balance rudder offset flap tweaking Ill now explain balancing roll detail stunt ship perfectly balanced roll sum moments around longitudinal axis equal zero attitudes flight see new word comes picture mo ments times have heard 32 Model Aviation FIG 4 GOOD BADWORSE OUTBOARD ROLLINBOARD ROLL 4-6 FT v32][b-1-10-1-10]] ND thinking distances flap hinge elevator hinge leading edge prop pay attention moments moment arms mo ment measure torsion around point axis moment arm distance point axis force causing moment Take wing-tip weight instance Before add wing-tip weight stunt ships youll notice hold ship underneath fuselage inboard wing should dip because board lateral weight greater out board lateral weight causing moment other words inboard roll addition wingtip weight creates moment equalizes inboard moment Also little weight added equalize mo ment caused weight lines ideal roll balance situation stunt ship have plane fly span wing exactly parallel ground level flight part pattern 4-6 ft undesired roll balance situation outboard wing flies higher inboard bad because ship will tend come flier during maneuv ers plane out balance better balance too much tip weight enough See Fig 4 ginners usually told times build rest lives using too much tip weight never breaking habit bad habit see lot decent fliers still doing Once flier can proficiently just loops AMA insides outsides enough ready FIG 5 balance ships properly means slapping tip weight indis criminately Assuming ship has proper aerody namic balance inboard wing lift equal outboard wing lift manifested good designs built warps static balancing roll can done almost perfectly right bench ship completed components attached find spot exactly middle fuselage near tail Support finest point possible damaging ship support nose crank shaft its full body stunt ship pro files use crankshaft because middle Instead use point middle fuselage near nose Add tip weight until outboard wing falls very slowly flying ship first time get somebody good eye outside circle see its actions inboard tip dips drastically fly out level bring down caused either three reasons IWarps See Fig 5 can gen erally detected before first flight cannot statically compensated compensated weight board tip dips drastically likely warp ships flaps now necessary tweak flaps lower leadout position latter better way explained later article tweaking inboard roll out board flap must bent up inboard flap down much necessary outboard roll caused warps tweak WARP CAUSING INBOARD ROLL NOTICE CROOKED TRAILING EDGES WARP CAUSING OUTBOARD ROLL flaps opposite way ships movable flaps add permanently fixed flap some sort position same directions just described 2Improper Vertical Balance generally problem proven designs home creations modifications usually susceptible balance statically tip weight dealing force gravity However balancing roll deal gravity also centrifugal force CL flying greater gravity during level flight Centrifugal force course what keeps tension lines actual pull feel handle Now force ship subject again subject moments men tioned before must equal roll bal ance situation roll moments caused gravity act lateral axis around longitudinal axis Visualize pic turing four-way lug wrench lateral axis ship instance similar axis lug apply pressure hands longitudinal axis ship similar axis lug goes nut turn stays stationary twists Now roll moments caused centrifugal force similar act different plane roll moments caused centrifugal force act vertical axis around longi tudinal axis So lug wrench compari son twisted 90 degrees gravity centrifugal force 90 degrees other level flight Im now going use commonly found situation involving improper vertical bal ance manifested ships have crankshaft inverted engine mounted chord center stabilizer same line See Fig 6 design type must have its leadouts lowered about 3/16 w center wing usually will see center makes just little sense put leadouts middle wing does put leadouts center wing CL Piper Cub reason because mass below wing therefore CG will below wing CG below wing center leadout position middle centrif ugal force will move CG up control lines leadout position CG will lie same straight line wing May1976 33 Balancing Roll will pivot about leadouts flying inboard roll See Fig 7 rule gov erning good vertical balance lateral axis wing span must lie parallel imaginary line connecting vertical leadout position ver tical CG position lateral axis mid-wing stunt ships lies right CG leadouts An example Nobler High-wing designs have lateral axis above parallel CG leadouts An example Piper Cub run Piper look leadouts extending way below wing tip first design Sundance set up like Piper yet still midwing design lowered engine standard vertical moments brought CG down Accordingly leadouts lowered also 1/16 comparing limited vertical distances much larger longitudinal lateral distances fractions make difference world have completed ship realize have vertical balance problem try vertically adjust leadouts tweak flaps according type roll case get familiar problem may run someday especially have stroke creativity Youll undoubtedly see others re member obscured problems CL flying Look out 3Improper Inboard Outboard Wing Spans stunt ship has inboard wing same size outboard wing will again fly inboard roll has noticed inboard wing panel usually longer outboard stunt ship dont know reason ship flies perfect circle such CL flying outboard wing moves faster board calculated ship 50 wing span flying 50 mph 60-ft lines outside tip flies little 3 mph faster inside tip airspeed lift produced outboard tip will come up Hence board roll corrected merely tip weight FIG 6 VERTICAL DISTRIBUTION OF MASS THRUST LINE WING AND STABILIZER ON SAME LINE ENGINE AND LANDING GEAR ARE CRITICAL VERTICAL CENTER CAUSING MOMENTS THE ENGINE BECAUSE IT IS VERY MASSIVE THE LANDING GEAR BECAUSE IT IS LONG LOW ENGINE MOUNT AND LANDING GEAR CAUSE VERTICAL CG TO LIE BELOW CENTER OF WING CONSEQUENTLY LEADOUTS MUST BE LOWEREO TO THE VERTICAL CG POSITION ideal ratio inboard outboard wing spans has yet found however problem considerably longer side panels ships function consistently respect level flight during maneuvers longer inside wing panels some fliers say ships fly dead level during level flight have tendencies roll turning corners flaps deflected maneuver lift changes lift ratio inboard outboard wing panels also may change effect roll moments during maneuvers during level flight may different Another problem considerably longer inside wing panels during windy weather ships less stable especially inconsistent winds hit ting gust should see inboard wing pop up sharply Immediately after centrifugal force will tend neutralize opposite will happenthe inboard wing pops down happens unwanted oscillating roll usually known bobbling Sometimes right wind will bobble around forever trend northeast present use equal span wing panels major reason eliminate rolling corners So hear statement Im going equal panels should know what theyre talking about believe idea has merit know final answer rolling maneuvers believe part problem lies horizontal tail surfaces stabilizer elevator have fully researched yet soon have results will presented theory hope fact part have talking about balance situations apply level flight Just during last few para graphs have spoken briefly about balance situations during maneuvers mentioned common ship fly level during level flight roll maneuvers Although problem separate topic itself will now give two basic causes corrections 1Aerodynamic Imbalance Acting flaps deflected common situation too much lift inboard wing panel maneuvers because longer inboard panel flaps have tried tip weight possibility find inboard wing panel still giving too much lift cut board flap chordwise After have spent months beautiful stunt ship going hurt what wisest choice 2 points finish 10 20 points execution patcon tinued page 95 TRIFUGAL FORCE FIG 7 LOW VERTICAL MASS DISTRIBUTION THRUST LINE ENGINE AND STABILIZER ON SAME LINE IF LEADOUTS ARE HERE AT CENTER OF WING CENTRIFUGAL FORCE WILL CAUSE CG TO RISE LATERAL AXIS TO THIS POSITION INBOARD ROLL LLPJ IMAGINARY LINE ELOWLEADOUT POSITION CENTER OF WINGLEADOUTS MUST BE HERE TO AVOID INBOARD ROLL CENTRIFUGAL FORCE LOW INVERTED ENGINE MOUNT BRINGING CG BELOW CENTER 34 Model Aviation THE BEARCAT CORSAIR & SKYRAIDER ARE GREAT ALL AROUND FUN AIRPLANES.EXCELLENT COMPETITORS EXTREMELY REALISTIC TREMENDOUS STRENGTH-DURABILITY QUALITY. THE STRUCTURAL CONCEPT USED IN THIS SERIES OF NEW MODELS IS SO MUCH FUN TO ASSEMBLE WE DONT TERM THEM AS KITS ASSEMBLY MODELS IS FAR MORE APPROPRIATE SIMPLE AND EASY TO COMPLETE TOUGH DURABLE MODELS--LOOK LIKE THE REAL THING ONCE YOU FINISH ONE YOUVE HAD SO MUCH FUN YOU WILL WANT TO BUILD ANOTHER--AND ANOTHER. EACH PLANE HAS OVER 300 INCHES OF WING AREA SUPER RUGGED DETACHABLE LANDING GEAR DETAILED CLEAR CANOPY FULL SET DECALS PRECISELY SHAPED PARTS AIRFOILED TAIL SURFACES MUCH HARDWARE. INCLUDING SLICK CARRIER-HOOK MECHANISM ETC. FLASH G-S ASSEMBLY MODELS COMING ON STRONG BY RIC FLYERS USING 09-19 ENGINES BEARCAT : THE G-S CONTROL SYSTEM IS THE ULTIMATE DEVELOPMENT OF THE FINE SYSTEM THAT MADE NAVY-CARRIER COME ALIVE IT WAS REFINED EXCLUSIVELY FOR THE MODELERTO GIVE HIM RELIABILITY QUALITY AND TOP VALUE FOR HIS INVESTMENT GS 3-LINE BELLCRANKS$ 495 ONT LONG-SPANUPRIGNY SNORT-SPANNOEl ED ORG SPARNYORTED SNORT-SPAN .VALUE. THESE ASSEMBLY MODELSINCLUDE NEW 3-LINE BELICRANK WITH LEAD-OUT CABLES TTA C H E D FINISHED FOR YOU WINGSPAN40$2495 SKYRAIDER AD-6 GOUR CLASS OF NEW PRODUCTS WILL STIMULATE MORE FLYING UCTS CORP INTL ACTION WHILE PROVIDING GREATER SAFETY SUCCESS AND FUN P 0 BOX 488 LA GRANDE OREGON 97850 USA ORDER DIRECTIF NOT AVAILABLE AT YOUR DEALERS Balancing Roll/Lella continued page 34 tern Cut flap little time Re member can keep cutting easily putting back drag 2Dynamic Imbalance During Ma neuvers stunt ship can fly dead level still have too much too little tip weight youll see ma neuvers Variations tip weight will make difference sometimes during level flight because centrifugal force especial ly ship well balanced ver tically Centrifugal force greater gravity during level flight can cancel out im balances susceptible gravity such tip weight However maneuvers particu larly sharp corners centrifugal force major force Gravitational forces com bined momentum Take stance ship coming out wingover Just before pulls out moving fastest speed ever will pattern Mass speed combine product what known momentum Without getting Physics Ill de scribe momentum thing makes feel like weigh descending elevator comes stop ship pulling out wingover same exact situation respect its down ward vertical movement coming stop Like person elevator weighs its imbalances weight also magnified So have half oz too much tip weight will come ounces too much tip weight pullout ship will have out board roll outboard tip dipping until centrifugal force neutralizes again level flight momentum wingover gone have just presented roll problems causes Now heres summary showing symptoms correct can referred like chart ship should first tested roll level inverted flight Forget about its characteristics during maneuvers until problems resolved bal anced correctly will never fly cor rectly during maneuvers ship should flown level inverted same height control hand fliers between four five feet Someone good eye preferably another stunt flier should watch ship outside circle compare follow procedures Roll Symptoms Corrections Level Inverted Flight Inboard Roll Outbard tip up level flight Outboard Roll Outboard Tip down inverted flight aero dynamic problem probably wrap must tweak flapsoutboard flap up inboard flap down Tweak much necessary get wing flying parallel ground Tweaking best solu tion although easiest Tweaked flaps job speed creased speeds ship will roll direction tweaked lower speeds enough compensate initial imbalance Also means flying level deflected flaps induces drag reduces lift better solution lower leadout position possible doing encounter aerodynamic imbalance equal opposite ver tical imbalance no drag induced problem vertical im balance fluctuates maneuvers because fluctuating centrifugal force best solution build straight begin Outboard Roll Outboard tip down level flight Inboard Roll Outboard tip up inverted flight oppo site previous problem Tweak flaps opposite direction raise leadouts possible can also add weight landing gear bottom strut creating counterbalancing ver tical moment easier changing leadout position does same thing suggest rather tweaking Outboard Roll both level inverted flight merely tip weight problem Simply add tip weight until wing flies parallel ground Outboard Roll both level inverted May1976 95 G-S HANDLE 5995 $2495 WINGSPAN 38 LENGTH 29 CORSAIR F4U-5 $2495 WINGSPAN 38LENGTH 29 p TOUGH fILL LINK NYLONAIIi SNAPS-ON AND HOLDS TIGHT 4-Piece ball link set No 182 prefer permanent installation Includes nylon link threaded coupler steel ball pin washer peening HIGHAbsolutely no linkage play STRENGTHball links used Nylon link STEELhelps reduce viabration looks goodtool Only 85 51/2 &6 dia inflatable WHEELS two piece bolttogether hubs BIG airplanes 40CR 4dia $795 45CR- 41/2dia- $995 50CR- 5dia -$1195 550 R-5dia-$135 60CR- 6- dia $1595 r-7 S rnwws wrrs iz su KWUIU5 WITh l2/\ Ip2 Super Realistic DUBRO PRODUCTS INCORPORATED 480 Bonner Road Wauconda IllinoIs 60064 USA Balancing Roll continued flight too much tip weight Simply remove weight outboard tip have means add some weight inboard tip rarely happens full-body stunt ships very common profiles because en gine tank right side Also because modelers usually put heaviest wood outboard wing panel slap excessive tip weight age old bad habits modeling Please need weight inboard tip use Also constructing ship can gouge weight bulky leading trailing edges usually come profile kits Keep mind now symptoms corrections apply ship flying level inverted flight ship static regard vertical move ment During maneuvers dynamic situation forces constantly changing may out balance during maneuv ers particularly squares touched bit article needs its own space explanation However what have just presented heart roll balance problems understand apply what has said youll wind up good perform ing ship respect Keep mind also situations isolated very possible probable will have combination problems perhaps something isnt clear read again think about what being said its still clear ask questions address 2850 E 196 St Bronx NY 10461 Until next month. Stunt Next month author discusses Balane ing Yaw CL Combat/Johnson continued page 29 soon available first unit saw operation Goodyear appears handle well restart first flip easy plugs yes did beat Rossi 15s day has general escalation horsepower FAI event over especially Britain day might say goodbye stinky old diesel altogether Hows plug have best powerful assortment engines time until few months ago full potential couldnt tapped because universal weak link glow plug Gb Bee seems have partially filled gap least Speed Racing folks Gb Bee takes potent battery fire off usually requires reduc tion head clearance proper running Initial testing Combat motors seems indicate easy flame-outs under humid conditions later model RC sport Gb Bees may remedy situation England comes another new plug designed racing useful Com bat Long time Team Race competitor Charlie Taylor has developed new 1 volt plug use racing engines needs no mechanical changes make work right Some test samples have run over 30 flights 1976 combat Tigre no distortion element blown seals equivalent ten full races Rossi Goodyear K&B 40 Rat Racer also no ill effects George goes flying Everybody knows George somewhere hes guy didnt very well last year figures Mark VII Imperfecta 35 let him down because didnt have latest super magnum racing head Next year will 70% nitro nasty medicine tank plane turns tighter cause old critter kept hitting ground George never thought practice because too ex pensive replacing broken motors figures engine makes lots noise goes fast once awhile can count pure luck pull him through Actually George wouldnt know dif ference between ABC piston/liner ICBM ABC stands aluminum beer can right Its start 1976 season look forward some real good Com bat also take quick peek back past performance eh George Slow Combat Im opinion difference between Fast Slow combat flying precision over 100 mph little precision just aim hope kill system works good anything Slow planes fly 70-90 bracket is possible accurately get little cuts follow another ship through intricate maneuvers So encourage banzai artist re ward quick kill would seem better have full five minutes Combat air time cuts counting spec tacular five-second kill takes less skill 300 seconds Combat Its maneuver time Everything al ways wanted know inverted clover leaf intercepts plant body out center circle Lets start easy time thats park body relation other guy opponent has three options open him youre tail either up down ground Draw neat circle floor get another combat lad pretend youre flying slow motion youll soon see cer tain maneuvers easily blocked just raising arm up front eyes standing between him imaginary plane trick somewhat hinder opponents view plane make enough nuisance yourself hell have turn direction youve planned him kind silly game insight can invaluable really want look professional might want 96 Model Aviation

Chris Lella Balancing Roll Some valuable tips will make model fly better inverted during maneuvers .L Stunt S1iis both level flight upright WHEN GETTING discussions about various characteristics ships modelers find peo ple have hard time expressing selves Also fliers have vague ideas lack understanding planes fly way build certain way think reason because modeling complete universal language due certain unfamiliarity aero nauticsboth terms physics ever does have mathema tical whiz become acquainted laws terms flight As matter fact cases mere ability add subtract multiply divide necessary make world aeronautics much intelligible modeling what presently Anyone knows anything some people advance quicker others sometimes difference really ex treme Some fliers send 20 ships before can two maneuvers Others learn Stunt Pattern year find can jus pattern perfecting average competitive level others win Nationals takes ten 20 years hangups anyone has levels cannot pointed out too specifically requirements nec essary anyone advance modeling can Putting psychological reasons aside three basic requirements IFlying ability itself eye-hand coordi nation 2Building skills carpentry finishing etc 3The basic knowledge about thing person building flying third usually overlooked taken granted because cant touch hands like can ship controls themselves also because lot usually taken care kitted plans Some modelers build near perfec tion also can sometimes build ship perfectly wrong also take year find out what could have learned week because whimsical theories fly quicker ships themselves flying field particular aspect may discussed can have ten interpretations Some novice may hear spend year trying abstract best possibly find out wrong builders put big efforts trial-and-error method discovery fine advanced modeler because ideas likely new unique part ex perts ideas have roots what already May1976 31 first-line Stunt ships appearing minor variations theme Fokker E-1 typeits scale model genuine eye-catcher also has coupled flaps elevatorswhich par coursebut may set RC Stik types thinking See Shark article page 35 Astra 77 entered Ed Prohaska 15 Nats modified Formuls Sa Jim Kostecky design Finish markings remarkable Fox 40 Balancing Roll knows However anyone less expert trial error can probably will complete waste time true two reasons times what trying has already proven right wrong research results instead wasting time money experimenting other rea son well-rounded knowl edge modeling strong basic knowl edge aeronautics too variables unknown experi ments unknown variables chance coming up undesired result also chance coming up no result Given opportunity would like explain balance situation CL stunt ships probably significant aspect concerns us minia ture air machines fly Because using some aeronautical terms physics hope broaden basic knowl edge have just speaking some fliers will in-depth physical analyses just abstractions basic ex planations what required modelMOMENT LONGITUDINAL MOMENTPITCH LATERAL AXIS 1_____ t PRESSURE ing particularly CL stunt flying So fore word physics should scare anyone Its like maintaining ones own car person can understand automobiles efficiently maintain own car out being automotive engineer order three part series will Balancing Roll Yaw Pitch chose order respect intelligibil ity think Roll easiest understand Pitch hardest However dont confuse simplicity trimming respect Pitch easiest Roll hardest Balancing Roll best way start explaining exactly what plane may sound little too basic see leads us youll understand plane vehicle requires three dimensional control Id like elaborate three dimensions make unique vehicle Think simpler vehicles first train instance simplest vehicle cause its directional control always con stant Only its speed directly controlled Any right left lateral up down vertical movement determined fixed rail car little com plex vertical movement fixed road driver controls speed also right left directions un like train Now know plane can move freely up down must controlled way However addition movement vertically makes air vehi cle complex because allows roll Therefore controlled around three dimensional axes unlike car controlled around train controlled around Now think planes three axes axis goes through fuselage longitudinal axis movement around axis called Roll See Fig axis goes vertically through fuselage vertical axis movement around axis called Yaw See Fig 2 axis goes laterally through wingspan lateral axis movement around axis called Pitch See Fig 3 Obviously CL flying control directly planes pitch roll yaw should held constant ever have good flying plane particu larly stuntship roll yaw must held ideal constant other words ship must properly balanced ship can must balanced two ways static balance use weights other aerodynamic balance An example aerodynamic balance rudder offset flap tweaking Ill now explain balancing roll detail stunt ship perfectly balanced roll sum moments around longitudinal axis equal zero attitudes flight see new word comes picture mo ments times have heard 32 Model Aviation FIG 4 GOOD BADWORSE OUTBOARD ROLLINBOARD ROLL 4-6 FT v32][b-1-10-1-10]] ND thinking distances flap hinge elevator hinge leading edge prop pay attention moments moment arms mo ment measure torsion around point axis moment arm distance point axis force causing moment Take wing-tip weight instance Before add wing-tip weight stunt ships youll notice hold ship underneath fuselage inboard wing should dip because board lateral weight greater out board lateral weight causing moment other words inboard roll addition wingtip weight creates moment equalizes inboard moment Also little weight added equalize mo ment caused weight lines ideal roll balance situation stunt ship have plane fly span wing exactly parallel ground level flight part pattern 4-6 ft undesired roll balance situation outboard wing flies higher inboard bad because ship will tend come flier during maneuv ers plane out balance better balance too much tip weight enough See Fig 4 ginners usually told times build rest lives using too much tip weight never breaking habit bad habit see lot decent fliers still doing Once flier can proficiently just loops AMA insides outsides enough ready FIG 5 balance ships properly means slapping tip weight indis criminately Assuming ship has proper aerody namic balance inboard wing lift equal outboard wing lift manifested good designs built warps static balancing roll can done almost perfectly right bench ship completed components attached find spot exactly middle fuselage near tail Support finest point possible damaging ship support nose crank shaft its full body stunt ship pro files use crankshaft because middle Instead use point middle fuselage near nose Add tip weight until outboard wing falls very slowly flying ship first time get somebody good eye outside circle see its actions inboard tip dips drastically fly out level bring down caused either three reasons IWarps See Fig 5 can gen erally detected before first flight cannot statically compensated compensated weight board tip dips drastically likely warp ships flaps now necessary tweak flaps lower leadout position latter better way explained later article tweaking inboard roll out board flap must bent up inboard flap down much necessary outboard roll caused warps tweak WARP CAUSING INBOARD ROLL NOTICE CROOKED TRAILING EDGES WARP CAUSING OUTBOARD ROLL flaps opposite way ships movable flaps add permanently fixed flap some sort position same directions just described 2Improper Vertical Balance generally problem proven designs home creations modifications usually susceptible balance statically tip weight dealing force gravity However balancing roll deal gravity also centrifugal force CL flying greater gravity during level flight Centrifugal force course what keeps tension lines actual pull feel handle Now force ship subject again subject moments men tioned before must equal roll bal ance situation roll moments caused gravity act lateral axis around longitudinal axis Visualize pic turing four-way lug wrench lateral axis ship instance similar axis lug apply pressure hands longitudinal axis ship similar axis lug goes nut turn stays stationary twists Now roll moments caused centrifugal force similar act different plane roll moments caused centrifugal force act vertical axis around longi tudinal axis So lug wrench compari son twisted 90 degrees gravity centrifugal force 90 degrees other level flight Im now going use commonly found situation involving improper vertical bal ance manifested ships have crankshaft inverted engine mounted chord center stabilizer same line See Fig 6 design type must have its leadouts lowered about 3/16 w center wing usually will see center makes just little sense put leadouts middle wing does put leadouts center wing CL Piper Cub reason because mass below wing therefore CG will below wing CG below wing center leadout position middle centrif ugal force will move CG up control lines leadout position CG will lie same straight line wing May1976 33 Balancing Roll will pivot about leadouts flying inboard roll See Fig 7 rule gov erning good vertical balance lateral axis wing span must lie parallel imaginary line connecting vertical leadout position ver tical CG position lateral axis mid-wing stunt ships lies right CG leadouts An example Nobler High-wing designs have lateral axis above parallel CG leadouts An example Piper Cub run Piper look leadouts extending way below wing tip first design Sundance set up like Piper yet still midwing design lowered engine standard vertical moments brought CG down Accordingly leadouts lowered also 1/16 comparing limited vertical distances much larger longitudinal lateral distances fractions make difference world have completed ship realize have vertical balance problem try vertically adjust leadouts tweak flaps according type roll case get familiar problem may run someday especially have stroke creativity Youll undoubtedly see others re member obscured problems CL flying Look out 3Improper Inboard Outboard Wing Spans stunt ship has inboard wing same size outboard wing will again fly inboard roll has noticed inboard wing panel usually longer outboard stunt ship dont know reason ship flies perfect circle such CL flying outboard wing moves faster board calculated ship 50 wing span flying 50 mph 60-ft lines outside tip flies little 3 mph faster inside tip airspeed lift produced outboard tip will come up Hence board roll corrected merely tip weight FIG 6 VERTICAL DISTRIBUTION OF MASS THRUST LINE WING AND STABILIZER ON SAME LINE ENGINE AND LANDING GEAR ARE CRITICAL VERTICAL CENTER CAUSING MOMENTS THE ENGINE BECAUSE IT IS VERY MASSIVE THE LANDING GEAR BECAUSE IT IS LONG LOW ENGINE MOUNT AND LANDING GEAR CAUSE VERTICAL CG TO LIE BELOW CENTER OF WING CONSEQUENTLY LEADOUTS MUST BE LOWEREO TO THE VERTICAL CG POSITION ideal ratio inboard outboard wing spans has yet found however problem considerably longer side panels ships function consistently respect level flight during maneuvers longer inside wing panels some fliers say ships fly dead level during level flight have tendencies roll turning corners flaps deflected maneuver lift changes lift ratio inboard outboard wing panels also may change effect roll moments during maneuvers during level flight may different Another problem considerably longer inside wing panels during windy weather ships less stable especially inconsistent winds hit ting gust should see inboard wing pop up sharply Immediately after centrifugal force will tend neutralize opposite will happenthe inboard wing pops down happens unwanted oscillating roll usually known bobbling Sometimes right wind will bobble around forever trend northeast present use equal span wing panels major reason eliminate rolling corners So hear statement Im going equal panels should know what theyre talking about believe idea has merit know final answer rolling maneuvers believe part problem lies horizontal tail surfaces stabilizer elevator have fully researched yet soon have results will presented theory hope fact part have talking about balance situations apply level flight Just during last few para graphs have spoken briefly about balance situations during maneuvers mentioned common ship fly level during level flight roll maneuvers Although problem separate topic itself will now give two basic causes corrections 1Aerodynamic Imbalance Acting flaps deflected common situation too much lift inboard wing panel maneuvers because longer inboard panel flaps have tried tip weight possibility find inboard wing panel still giving too much lift cut board flap chordwise After have spent months beautiful stunt ship going hurt what wisest choice 2 points finish 10 20 points execution patcon tinued page 95 TRIFUGAL FORCE FIG 7 LOW VERTICAL MASS DISTRIBUTION THRUST LINE ENGINE AND STABILIZER ON SAME LINE IF LEADOUTS ARE HERE AT CENTER OF WING CENTRIFUGAL FORCE WILL CAUSE CG TO RISE LATERAL AXIS TO THIS POSITION INBOARD ROLL LLPJ IMAGINARY LINE ELOWLEADOUT POSITION CENTER OF WINGLEADOUTS MUST BE HERE TO AVOID INBOARD ROLL CENTRIFUGAL FORCE LOW INVERTED ENGINE MOUNT BRINGING CG BELOW CENTER 34 Model Aviation THE BEARCAT CORSAIR & SKYRAIDER ARE GREAT ALL AROUND FUN AIRPLANES.EXCELLENT COMPETITORS EXTREMELY REALISTIC TREMENDOUS STRENGTH-DURABILITY QUALITY. THE STRUCTURAL CONCEPT USED IN THIS SERIES OF NEW MODELS IS SO MUCH FUN TO ASSEMBLE WE DONT TERM THEM AS KITS ASSEMBLY MODELS IS FAR MORE APPROPRIATE SIMPLE AND EASY TO COMPLETE TOUGH DURABLE MODELS--LOOK LIKE THE REAL THING ONCE YOU FINISH ONE YOUVE HAD SO MUCH FUN YOU WILL WANT TO BUILD ANOTHER--AND ANOTHER. EACH PLANE HAS OVER 300 INCHES OF WING AREA SUPER RUGGED DETACHABLE LANDING GEAR DETAILED CLEAR CANOPY FULL SET DECALS PRECISELY SHAPED PARTS AIRFOILED TAIL SURFACES MUCH HARDWARE. INCLUDING SLICK CARRIER-HOOK MECHANISM ETC. FLASH G-S ASSEMBLY MODELS COMING ON STRONG BY RIC FLYERS USING 09-19 ENGINES BEARCAT : THE G-S CONTROL SYSTEM IS THE ULTIMATE DEVELOPMENT OF THE FINE SYSTEM THAT MADE NAVY-CARRIER COME ALIVE IT WAS REFINED EXCLUSIVELY FOR THE MODELERTO GIVE HIM RELIABILITY QUALITY AND TOP VALUE FOR HIS INVESTMENT GS 3-LINE BELLCRANKS$ 495 ONT LONG-SPANUPRIGNY SNORT-SPANNOEl ED ORG SPARNYORTED SNORT-SPAN .VALUE. THESE ASSEMBLY MODELSINCLUDE NEW 3-LINE BELICRANK WITH LEAD-OUT CABLES TTA C H E D FINISHED FOR YOU WINGSPAN40$2495 SKYRAIDER AD-6 GOUR CLASS OF NEW PRODUCTS WILL STIMULATE MORE FLYING UCTS CORP INTL ACTION WHILE PROVIDING GREATER SAFETY SUCCESS AND FUN P 0 BOX 488 LA GRANDE OREGON 97850 USA ORDER DIRECTIF NOT AVAILABLE AT YOUR DEALERS Balancing Roll/Lella continued page 34 tern Cut flap little time Re member can keep cutting easily putting back drag 2Dynamic Imbalance During Ma neuvers stunt ship can fly dead level still have too much too little tip weight youll see ma neuvers Variations tip weight will make difference sometimes during level flight because centrifugal force especial ly ship well balanced ver tically Centrifugal force greater gravity during level flight can cancel out im balances susceptible gravity such tip weight However maneuvers particu larly sharp corners centrifugal force major force Gravitational forces com bined momentum Take stance ship coming out wingover Just before pulls out moving fastest speed ever will pattern Mass speed combine product what known momentum Without getting Physics Ill de scribe momentum thing makes feel like weigh descending elevator comes stop ship pulling out wingover same exact situation respect its down ward vertical movement coming stop Like person elevator weighs its imbalances weight also magnified So have half oz too much tip weight will come ounces too much tip weight pullout ship will have out board roll outboard tip dipping until centrifugal force neutralizes again level flight momentum wingover gone have just presented roll problems causes Now heres summary showing symptoms correct can referred like chart ship should first tested roll level inverted flight Forget about its characteristics during maneuvers until problems resolved bal anced correctly will never fly cor rectly during maneuvers ship should flown level inverted same height control hand fliers between four five feet Someone good eye preferably another stunt flier should watch ship outside circle compare follow procedures Roll Symptoms Corrections Level Inverted Flight Inboard Roll Outbard tip up level flight Outboard Roll Outboard Tip down inverted flight aero dynamic problem probably wrap must tweak flapsoutboard flap up inboard flap down Tweak much necessary get wing flying parallel ground Tweaking best solu tion although easiest Tweaked flaps job speed creased speeds ship will roll direction tweaked lower speeds enough compensate initial imbalance Also means flying level deflected flaps induces drag reduces lift better solution lower leadout position possible doing encounter aerodynamic imbalance equal opposite ver tical imbalance no drag induced problem vertical im balance fluctuates maneuvers because fluctuating centrifugal force best solution build straight begin Outboard Roll Outboard tip down level flight Inboard Roll Outboard tip up inverted flight oppo site previous problem Tweak flaps opposite direction raise leadouts possible can also add weight landing gear bottom strut creating counterbalancing ver tical moment easier changing leadout position does same thing suggest rather tweaking Outboard Roll both level inverted flight merely tip weight problem Simply add tip weight until wing flies parallel ground Outboard Roll both level inverted May1976 95 G-S HANDLE 5995 $2495 WINGSPAN 38 LENGTH 29 CORSAIR F4U-5 $2495 WINGSPAN 38LENGTH 29 p TOUGH fILL LINK NYLONAIIi SNAPS-ON AND HOLDS TIGHT 4-Piece ball link set No 182 prefer permanent installation Includes nylon link threaded coupler steel ball pin washer peening HIGHAbsolutely no linkage play STRENGTHball links used Nylon link STEELhelps reduce viabration looks goodtool Only 85 51/2 &6 dia inflatable WHEELS two piece bolttogether hubs BIG airplanes 40CR 4dia $795 45CR- 41/2dia- $995 50CR- 5dia -$1195 550 R-5dia-$135 60CR- 6- dia $1595 r-7 S rnwws wrrs iz su KWUIU5 WITh l2/\ Ip2 Super Realistic DUBRO PRODUCTS INCORPORATED 480 Bonner Road Wauconda IllinoIs 60064 USA Balancing Roll continued flight too much tip weight Simply remove weight outboard tip have means add some weight inboard tip rarely happens full-body stunt ships very common profiles because en gine tank right side Also because modelers usually put heaviest wood outboard wing panel slap excessive tip weight age old bad habits modeling Please need weight inboard tip use Also constructing ship can gouge weight bulky leading trailing edges usually come profile kits Keep mind now symptoms corrections apply ship flying level inverted flight ship static regard vertical move ment During maneuvers dynamic situation forces constantly changing may out balance during maneuv ers particularly squares touched bit article needs its own space explanation However what have just presented heart roll balance problems understand apply what has said youll wind up good perform ing ship respect Keep mind also situations isolated very possible probable will have combination problems perhaps something isnt clear read again think about what being said its still clear ask questions address 2850 E 196 St Bronx NY 10461 Until next month. Stunt Next month author discusses Balane ing Yaw CL Combat/Johnson continued page 29 soon available first unit saw operation Goodyear appears handle well restart first flip easy plugs yes did beat Rossi 15s day has general escalation horsepower FAI event over especially Britain day might say goodbye stinky old diesel altogether Hows plug have best powerful assortment engines time until few months ago full potential couldnt tapped because universal weak link glow plug Gb Bee seems have partially filled gap least Speed Racing folks Gb Bee takes potent battery fire off usually requires reduc tion head clearance proper running Initial testing Combat motors seems indicate easy flame-outs under humid conditions later model RC sport Gb Bees may remedy situation England comes another new plug designed racing useful Com bat Long time Team Race competitor Charlie Taylor has developed new 1 volt plug use racing engines needs no mechanical changes make work right Some test samples have run over 30 flights 1976 combat Tigre no distortion element blown seals equivalent ten full races Rossi Goodyear K&B 40 Rat Racer also no ill effects George goes flying Everybody knows George somewhere hes guy didnt very well last year figures Mark VII Imperfecta 35 let him down because didnt have latest super magnum racing head Next year will 70% nitro nasty medicine tank plane turns tighter cause old critter kept hitting ground George never thought practice because too ex pensive replacing broken motors figures engine makes lots noise goes fast once awhile can count pure luck pull him through Actually George wouldnt know dif ference between ABC piston/liner ICBM ABC stands aluminum beer can right Its start 1976 season look forward some real good Com bat also take quick peek back past performance eh George Slow Combat Im opinion difference between Fast Slow combat flying precision over 100 mph little precision just aim hope kill system works good anything Slow planes fly 70-90 bracket is possible accurately get little cuts follow another ship through intricate maneuvers So encourage banzai artist re ward quick kill would seem better have full five minutes Combat air time cuts counting spec tacular five-second kill takes less skill 300 seconds Combat Its maneuver time Everything al ways wanted know inverted clover leaf intercepts plant body out center circle Lets start easy time thats park body relation other guy opponent has three options open him youre tail either up down ground Draw neat circle floor get another combat lad pretend youre flying slow motion youll soon see cer tain maneuvers easily blocked just raising arm up front eyes standing between him imaginary plane trick somewhat hinder opponents view plane make enough nuisance yourself hell have turn direction youve planned him kind silly game insight can invaluable really want look professional might want 96 Model Aviation