Lift Thrust Are Good DPAG EBill Layers weight distributed around 0 center gravity aircraft determines will react control inputs THRUST about hangar session 7much givesusmuchtothink about act upon V Drag WEIGHT Are Bad GUYSN THE COVERING plane shown drawings picture accounts 5i% models total weight fill fuel tank shifts center gravity CG forward just shade over three-quarters inch just couple things discovered recently decided learn about weight planes build see enjoy designing own planes Im inclined over-design build models too heavy strength really need figured Id go campaign reduce excess weight latest design weigh components went along truly enlightening experience yes pun intended though plane came out bit heavier hoped model has 1250 sq wing powered Supertigre 60 builtup structures conventional balsa Lite Ply plywood few pieces hard wood block illustrations show rest article about plane itself Its about should look weight reduction weight distribution ideas still provide enough strength high-stress areas Does mean RC models should lightened No design has its right recom mended weight give realistic performance penetration other desirable flight characteristics average guy like sometimes scratch-builds modi fies kits selects own materials components doing can easily overburden otherwise good design excess weightor weight misplaced Ill use model illustrated examples completed plane fuel weighs 9 lb 13 oz weighed major components some indi vidual parts well Built-up structures weighed before after covering Accuracy figures limited what could get household postal scales Numbers rounded off avoid com plication interested com parisons precision weight distribution chart shows percent weight major com ponent contributes total weight Well start looking numbers drawing some reasonable conclusions biggest part total weight wing29% Thats too surprising After going put airplane air fly wing what makes whole concept work other 71% hanging wings center sec tion structure better fail loop pull two Gs arithmetic tells wing will supporting 14 lb pullout almost fatal dive mightpull four Gs thatwould exert 28-lb pull wing 45-oz wing about right Actually thats issue Weight does mean strength Weight should very carefidly invested should invest weight dollars spend countsto strengthen high-stress points plane Conversely should minimize weight low-stress areas should invest weight wing answer good stout spars spar reinforcement plates center section Stress fuselagh-mounted wing like greatest center becomes progressively less toward tips lifting loads concentrated center transferred fuselage attachment points strut-supported wings J-3 Cub strut attachment points share burden center section center section doesnt have beefed up heavily such design strut attach ment points must also tough enough share course struts also add weight However airplane has tradeoffs strut-equipped plane tradeoff increased weight 38 Model Aviation LIFT models use heavy stuff hardwood plywood epoxy great strength needed Keep balance structure light good judgment will allow fuselage comes second 23% total weight ties other components together absorbs stresses Again invest wisely weight use strong heavy materials strength needed places needing lot tention attachment main land ing gear nose gear tail wheel Youve no doubt seen terrible loads taken landing gears upward sideways backward Toughen up attachment points way will oppose loads engine mount structure should stoutest areas model Normal stresses tough enough fuselage prop-first contacts ground create structural loads difficult measure Tail surface attachment points should tough lightweight Sport planes dont create heavy in-flight stresses tall higher airspeeds quicker maneuvers beefier points should means have adequate fuselage strength attaching wing example take note fact 71% planes weight hanging dear life onto three -20 nylon bolts fuse lage members thread power system accounting 16% weight ranks third includes engine muffler prop engine mount tank C-size onboard booster battery Im pleased figure especially find ST 60 alone accounted 8% weight Todays engines have high power-to-weight ratio dont think can gripe Im happy landing gear wheels struts tail wheel assem bly being 13% total item shocked tallied up numbers building plane just could carry around some wheels origi nal plans called 5-in wheels found weighed 1 lb 2 oz rushed back hobby shop traded smaller 4-in ones Ive got hedge bit complaint about weight wheels make lot touch-and-go landings like able taxi through rough terrain landing gear wheels take severe beatingbut still balk 13% Shop around select wheels isnt bad idea take postal scale Walt Good other pioneers permitted self-satisfied grin see 10% total weight fourservo airborne radio system Todays de signers manufacturers should com mended reliable durable lightweight sets market However area can save some weight shopping around comparing radio specifications Excellent airborne units offered have small lightweight receiv WING % PowIR LANDING 0GEAR 137 RADIO 10% Nsc 4 ers servos However dont use planes larger recommended RC equipment manufacturer completed tail assembly weighed just 7 oz 5% total Nothing really exciting Just try keep tail surfaces light adequate strength center section attachment points just like wing stresses concentrated Last list 4% miscellaneous Yes surprised figure ever miscellaneous weight can quickly add up hardware attaching engine mount landing gear wing tail packing attachments radio gear tail struts exhaust extension added afterthought etc Theres much can about miscellaneous pieces except analyze everything put Look ways saving ounces Ask yourself Can make special bracket out plywood instead metal Better yet can make out nylon Are weight distribution percent ages recommended ones No Im just reporting what found out about plane However recommend approach describe method alyzing own building methods selection materials components Would percentages same larger smaller planes Yes no Some weights would change almost pro portionately sizebuilt-up structures example Other items weight may change same way example four-servo Kraft radio would about 24% weight Falcon 56or 8% 9-ft J-3 Cub Thats enough about weight distribution Now commentator Paul Harvey would say youre goingto hear rest story~ point about weight distribution have contend center gravity CG locationand make fall right place Kits plans usually give fore-and-aft location some give acceptable range get right place main consideration wait until plane finished check out wait may have add ballast relocate radio gear possibly have change some pushrod July1986 39 author-designed model subject detailed weight analysis testing con ducted conclusions makethe old adage building lightness moreappropriate TIGER TAIL 45 DELHI ALL MLSA KIT An new Tiger Tail 120 four strokes Designed especial F3A Turn around competition balsa kit machined wood parts Hardware package includes plug-in adjustable stab parts new wing mounts Wing Span 72 inLength -60 Wing Nea 860 sq inWeight 8 lb Complete Delux Kit$15995 COMBO DEAL-Tiger Tail 4S Enyal2OR$395OO PUIS4N AIUSTASLE 51*3 KENT last can optmze stab nadence b fhght characteristics nair glass filled adjusters e included prourde micro screar adjustment smaller front tube Main tube atuminum nuts GP NEW WING MOINflING SE nung mounting system deaekped Ron Chidgey rs fad neat accurate stays tight Three aylon buckets screnus machined nuing blocht included $L95 See Your Dealer Order Direct Include $1 50 Per Item UPS GATOR R/C PRODUCTS 3713 Pompano Dnve 0 Pensacola FL 325140 Phorse 904 476-8639 Save Money lable semi-kit $1290 supply wood hardwarea-F As Featured $18900 Nlarch 86 RCM Magazine wing span44 wing area609 sq length56 weight65 lbs engine40-462 cycle radio4 channel Boa PARKINSON FLYING MODELS RRI Queens yule Ontario LOG iRO Canada Tel 416 478-2632 Z Please add $2000 ship handling Dealer Inquiries Invited lengths Its best determine receiver servo battery positions late con struction possible can shift weight elements back forth achieve correct balance position Theres locating CG should center plane right left CG isnt centered will forever trying trim out problem thatjust wont go away CG isnt centered left right check see have mounted heavy object side wing can culprit side has heavier material other must add weight lighter side wing small nails pieces solder imbedded tip can trick Better yet try weighing wing materials before assembly perhaps can achieve neutral balance build avoid later problem Theres Vhere vertical position CG should few plans define others just leave doubt doubt some things consider CG located well below center lift can provide pendulum effect type stability adds longitudinal stability keeps nose pitching up down improves lateral stability keeps plane roll ing right left heavy wheels must have brought CG down notch two right amount pendulum effect can enhance stability Tco much may overly stable may responsive controls would like plans dont define location will have consider type aircraft involved kind performance want Lets go off another tangent concentration weight Theoretically planes weight concentrated attheCGandlmeanall9lb l3ozthe plane would probably control line gang busters wouldnt able make hold still flight would change attitude slightest hint air turbulence control input An aircraft collection forces have balanced com promised other hand heavy items located extremities wing tips nose tail plane would sluggish reluctant change attitude planes dont fall either extreme tend toward latter case cant much about aircraft structures have weight best thing minimize weight extremities avoid ballasting can locate heavier items close can desired CG way youll have plane stable responsive controls Control surfaces also come scru tiny some planes high-speed situ ations flutter can tear up control surface structure supports way reduce possibility minimize weight aft hinge line greater Continued page 134 40 Model Aviation New GATOR High Performance Amphibian unique aircraft today has added line delta wing kits designed Laddie Mikulasko fully aerobetic off both water lend one-piece fiberglass fuselage cowl fairing wing-tip floats precision machine-cut foam delta wing assembles quickly easiiy4 02 lighter original balas version Unplug landing gear Iwater-tight nose wheel mount factory instailedl fly off water snow ice addition floats skils Stability wind penetration overall performance combined un believably low landing speed make Nffthstsr 2001 best designe yet kit has build test flown Laddie Mikulasko hia complete approval Two channel wheel radio unbeatable performance Servo reversing & end point adjustments both channels Continuously adjustable steering rate Adjustable steering wheel tension lncludes receiver switch harness battery holder Comes withwo JRS5O5 servos Available 2TMHz 9fLV An extremely reliable radio Two channel system cars boats lncludes battery case drycells receiver two JRS5O5 servos Available 27 MHz BOTH RADIOS ARE COVERED BY CIRCUS HOBBIES WARRANTY TAKE ADVANTAGE OF OUR ERROR AND SAVE WHILE SUPPLIES LAST PRICES SUBJECT TO CHANGE TED TO QUANTITY ON HAND CALL TOLL FREE NOW TO PLACE YOUR ORDER 800 782-0022 3132 S HIGHLAND DRIVE VEGAS NEVADA 89109 Radio Technique/Myers Continued page 131 tones pocket pager will almost always sound mushy AM perfectly clear FM Contact District Frequency Coordina tor information loan scanner name will found AMA News sec tion right under District VPs name picture dont know what district Look state listed above VP col umns AMA News George M Myers 70 Froehlich Farm Rd HicksvIIe NY 11801 Good-Bad/Layers Continued page 40 weight behind hinges greater problem becomes Ailerons seem especially susceptible Invest tough heavy materials areas take control surface stresses hinge points control horn mountings Keep rest structure light possible Static dynamic balancing topics another time selecting wood construction gen erally speaking high-density wood tougher heavier low-density wood weaker lighter Select wood its purpose regarding strength weight ailerons mentioned before prefer high-density wood sub-spar mounts hinges low-density trailing edge reduce weight aft hinge line Analyze structure youre building take time select proper materials Lets talk about covering may Strohs man happen MonoKote man covering planes past always felt type covering added undue amount weight pleased find covering accounted 5Yi% total weight came 9 oz5 wing 2 fuselage 1 tail Considering MonoKotes toughness great finish considerable amount strength adds built-up structures think terrific investment weight fact bargain havent tried everything shop around check manufacturers spec sheets weight conscious well color con scious about nice-to-have dontreally-need items some planes lug around plane have exhaust pipe extension keep plane little cleaner C-size onboard booster NiCd convenience Theyre nice have add 3 oz plane may have gone overboard first couple planes used tubular nylon pushrods soon convinced expansion contraction tem perature changes wanted put up Since Ive used hardwood dowel pushrods logic telling larger plane larger dowel should Too late correct now estimate four-dowel pushrods Y16 dia threaded rod ends weigh little dds up Ill have rethink last point wed best close hangar doors Design own planes Think youve got some neat ideas Well think huge windshield neat weighs about 2 oz Doesnt sound bad until call eighth pound thats weightand thats name game See Sunday RC Scale/Wischers Continued page 43 stable air course lack wind during its flights helped model its high placing scoring bonus undercam bered airfoil now debatable subject FAI rules real reason problems such wing its inherent weakness same true very thin wings biplane Shallow depth spars requires made hardwood wire interstrut bracing becomes truly functional Muffler pressure Reliable muffler pressure fuel tank necessity reducing change fuel flow between full emp ty tank have used silicone rubber tube tank filling plugged after filling seal against pressure loss plug prefer machine screw Too coarse thread 134 Model Aviation - sent us tne wrong oraer ana over stocke radios leading sellers Japan identical er 2 Circus 2 radios except label price ALPINAZ BEAT 2 STICK RADIO I
Edition: Model Aviation - 1986/07
Page Numbers: 38, 39, 40, 134
Lift Thrust Are Good DPAG EBill Layers weight distributed around 0 center gravity aircraft determines will react control inputs THRUST about hangar session 7much givesusmuchtothink about act upon V Drag WEIGHT Are Bad GUYSN THE COVERING plane shown drawings picture accounts 5i% models total weight fill fuel tank shifts center gravity CG forward just shade over three-quarters inch just couple things discovered recently decided learn about weight planes build see enjoy designing own planes Im inclined over-design build models too heavy strength really need figured Id go campaign reduce excess weight latest design weigh components went along truly enlightening experience yes pun intended though plane came out bit heavier hoped model has 1250 sq wing powered Supertigre 60 builtup structures conventional balsa Lite Ply plywood few pieces hard wood block illustrations show rest article about plane itself Its about should look weight reduction weight distribution ideas still provide enough strength high-stress areas Does mean RC models should lightened No design has its right recom mended weight give realistic performance penetration other desirable flight characteristics average guy like sometimes scratch-builds modi fies kits selects own materials components doing can easily overburden otherwise good design excess weightor weight misplaced Ill use model illustrated examples completed plane fuel weighs 9 lb 13 oz weighed major components some indi vidual parts well Built-up structures weighed before after covering Accuracy figures limited what could get household postal scales Numbers rounded off avoid com plication interested com parisons precision weight distribution chart shows percent weight major com ponent contributes total weight Well start looking numbers drawing some reasonable conclusions biggest part total weight wing29% Thats too surprising After going put airplane air fly wing what makes whole concept work other 71% hanging wings center sec tion structure better fail loop pull two Gs arithmetic tells wing will supporting 14 lb pullout almost fatal dive mightpull four Gs thatwould exert 28-lb pull wing 45-oz wing about right Actually thats issue Weight does mean strength Weight should very carefidly invested should invest weight dollars spend countsto strengthen high-stress points plane Conversely should minimize weight low-stress areas should invest weight wing answer good stout spars spar reinforcement plates center section Stress fuselagh-mounted wing like greatest center becomes progressively less toward tips lifting loads concentrated center transferred fuselage attachment points strut-supported wings J-3 Cub strut attachment points share burden center section center section doesnt have beefed up heavily such design strut attach ment points must also tough enough share course struts also add weight However airplane has tradeoffs strut-equipped plane tradeoff increased weight 38 Model Aviation LIFT models use heavy stuff hardwood plywood epoxy great strength needed Keep balance structure light good judgment will allow fuselage comes second 23% total weight ties other components together absorbs stresses Again invest wisely weight use strong heavy materials strength needed places needing lot tention attachment main land ing gear nose gear tail wheel Youve no doubt seen terrible loads taken landing gears upward sideways backward Toughen up attachment points way will oppose loads engine mount structure should stoutest areas model Normal stresses tough enough fuselage prop-first contacts ground create structural loads difficult measure Tail surface attachment points should tough lightweight Sport planes dont create heavy in-flight stresses tall higher airspeeds quicker maneuvers beefier points should means have adequate fuselage strength attaching wing example take note fact 71% planes weight hanging dear life onto three -20 nylon bolts fuse lage members thread power system accounting 16% weight ranks third includes engine muffler prop engine mount tank C-size onboard booster battery Im pleased figure especially find ST 60 alone accounted 8% weight Todays engines have high power-to-weight ratio dont think can gripe Im happy landing gear wheels struts tail wheel assem bly being 13% total item shocked tallied up numbers building plane just could carry around some wheels origi nal plans called 5-in wheels found weighed 1 lb 2 oz rushed back hobby shop traded smaller 4-in ones Ive got hedge bit complaint about weight wheels make lot touch-and-go landings like able taxi through rough terrain landing gear wheels take severe beatingbut still balk 13% Shop around select wheels isnt bad idea take postal scale Walt Good other pioneers permitted self-satisfied grin see 10% total weight fourservo airborne radio system Todays de signers manufacturers should com mended reliable durable lightweight sets market However area can save some weight shopping around comparing radio specifications Excellent airborne units offered have small lightweight receiv WING % PowIR LANDING 0GEAR 137 RADIO 10% Nsc 4 ers servos However dont use planes larger recommended RC equipment manufacturer completed tail assembly weighed just 7 oz 5% total Nothing really exciting Just try keep tail surfaces light adequate strength center section attachment points just like wing stresses concentrated Last list 4% miscellaneous Yes surprised figure ever miscellaneous weight can quickly add up hardware attaching engine mount landing gear wing tail packing attachments radio gear tail struts exhaust extension added afterthought etc Theres much can about miscellaneous pieces except analyze everything put Look ways saving ounces Ask yourself Can make special bracket out plywood instead metal Better yet can make out nylon Are weight distribution percent ages recommended ones No Im just reporting what found out about plane However recommend approach describe method alyzing own building methods selection materials components Would percentages same larger smaller planes Yes no Some weights would change almost pro portionately sizebuilt-up structures example Other items weight may change same way example four-servo Kraft radio would about 24% weight Falcon 56or 8% 9-ft J-3 Cub Thats enough about weight distribution Now commentator Paul Harvey would say youre goingto hear rest story~ point about weight distribution have contend center gravity CG locationand make fall right place Kits plans usually give fore-and-aft location some give acceptable range get right place main consideration wait until plane finished check out wait may have add ballast relocate radio gear possibly have change some pushrod July1986 39 author-designed model subject detailed weight analysis testing con ducted conclusions makethe old adage building lightness moreappropriate TIGER TAIL 45 DELHI ALL MLSA KIT An new Tiger Tail 120 four strokes Designed especial F3A Turn around competition balsa kit machined wood parts Hardware package includes plug-in adjustable stab parts new wing mounts Wing Span 72 inLength -60 Wing Nea 860 sq inWeight 8 lb Complete Delux Kit$15995 COMBO DEAL-Tiger Tail 4S Enyal2OR$395OO PUIS4N AIUSTASLE 51*3 KENT last can optmze stab nadence b fhght characteristics nair glass filled adjusters e included prourde micro screar adjustment smaller front tube Main tube atuminum nuts GP NEW WING MOINflING SE nung mounting system deaekped Ron Chidgey rs fad neat accurate stays tight Three aylon buckets screnus machined nuing blocht included $L95 See Your Dealer Order Direct Include $1 50 Per Item UPS GATOR R/C PRODUCTS 3713 Pompano Dnve 0 Pensacola FL 325140 Phorse 904 476-8639 Save Money lable semi-kit $1290 supply wood hardwarea-F As Featured $18900 Nlarch 86 RCM Magazine wing span44 wing area609 sq length56 weight65 lbs engine40-462 cycle radio4 channel Boa PARKINSON FLYING MODELS RRI Queens yule Ontario LOG iRO Canada Tel 416 478-2632 Z Please add $2000 ship handling Dealer Inquiries Invited lengths Its best determine receiver servo battery positions late con struction possible can shift weight elements back forth achieve correct balance position Theres locating CG should center plane right left CG isnt centered will forever trying trim out problem thatjust wont go away CG isnt centered left right check see have mounted heavy object side wing can culprit side has heavier material other must add weight lighter side wing small nails pieces solder imbedded tip can trick Better yet try weighing wing materials before assembly perhaps can achieve neutral balance build avoid later problem Theres Vhere vertical position CG should few plans define others just leave doubt doubt some things consider CG located well below center lift can provide pendulum effect type stability adds longitudinal stability keeps nose pitching up down improves lateral stability keeps plane roll ing right left heavy wheels must have brought CG down notch two right amount pendulum effect can enhance stability Tco much may overly stable may responsive controls would like plans dont define location will have consider type aircraft involved kind performance want Lets go off another tangent concentration weight Theoretically planes weight concentrated attheCGandlmeanall9lb l3ozthe plane would probably control line gang busters wouldnt able make hold still flight would change attitude slightest hint air turbulence control input An aircraft collection forces have balanced com promised other hand heavy items located extremities wing tips nose tail plane would sluggish reluctant change attitude planes dont fall either extreme tend toward latter case cant much about aircraft structures have weight best thing minimize weight extremities avoid ballasting can locate heavier items close can desired CG way youll have plane stable responsive controls Control surfaces also come scru tiny some planes high-speed situ ations flutter can tear up control surface structure supports way reduce possibility minimize weight aft hinge line greater Continued page 134 40 Model Aviation New GATOR High Performance Amphibian unique aircraft today has added line delta wing kits designed Laddie Mikulasko fully aerobetic off both water lend one-piece fiberglass fuselage cowl fairing wing-tip floats precision machine-cut foam delta wing assembles quickly easiiy4 02 lighter original balas version Unplug landing gear Iwater-tight nose wheel mount factory instailedl fly off water snow ice addition floats skils Stability wind penetration overall performance combined un believably low landing speed make Nffthstsr 2001 best designe yet kit has build test flown Laddie Mikulasko hia complete approval Two channel wheel radio unbeatable performance Servo reversing & end point adjustments both channels Continuously adjustable steering rate Adjustable steering wheel tension lncludes receiver switch harness battery holder Comes withwo JRS5O5 servos Available 2TMHz 9fLV An extremely reliable radio Two channel system cars boats lncludes battery case drycells receiver two JRS5O5 servos Available 27 MHz BOTH RADIOS ARE COVERED BY CIRCUS HOBBIES WARRANTY TAKE ADVANTAGE OF OUR ERROR AND SAVE WHILE SUPPLIES LAST PRICES SUBJECT TO CHANGE TED TO QUANTITY ON HAND CALL TOLL FREE NOW TO PLACE YOUR ORDER 800 782-0022 3132 S HIGHLAND DRIVE VEGAS NEVADA 89109 Radio Technique/Myers Continued page 131 tones pocket pager will almost always sound mushy AM perfectly clear FM Contact District Frequency Coordina tor information loan scanner name will found AMA News sec tion right under District VPs name picture dont know what district Look state listed above VP col umns AMA News George M Myers 70 Froehlich Farm Rd HicksvIIe NY 11801 Good-Bad/Layers Continued page 40 weight behind hinges greater problem becomes Ailerons seem especially susceptible Invest tough heavy materials areas take control surface stresses hinge points control horn mountings Keep rest structure light possible Static dynamic balancing topics another time selecting wood construction gen erally speaking high-density wood tougher heavier low-density wood weaker lighter Select wood its purpose regarding strength weight ailerons mentioned before prefer high-density wood sub-spar mounts hinges low-density trailing edge reduce weight aft hinge line Analyze structure youre building take time select proper materials Lets talk about covering may Strohs man happen MonoKote man covering planes past always felt type covering added undue amount weight pleased find covering accounted 5Yi% total weight came 9 oz5 wing 2 fuselage 1 tail Considering MonoKotes toughness great finish considerable amount strength adds built-up structures think terrific investment weight fact bargain havent tried everything shop around check manufacturers spec sheets weight conscious well color con scious about nice-to-have dontreally-need items some planes lug around plane have exhaust pipe extension keep plane little cleaner C-size onboard booster NiCd convenience Theyre nice have add 3 oz plane may have gone overboard first couple planes used tubular nylon pushrods soon convinced expansion contraction tem perature changes wanted put up Since Ive used hardwood dowel pushrods logic telling larger plane larger dowel should Too late correct now estimate four-dowel pushrods Y16 dia threaded rod ends weigh little dds up Ill have rethink last point wed best close hangar doors Design own planes Think youve got some neat ideas Well think huge windshield neat weighs about 2 oz Doesnt sound bad until call eighth pound thats weightand thats name game See Sunday RC Scale/Wischers Continued page 43 stable air course lack wind during its flights helped model its high placing scoring bonus undercam bered airfoil now debatable subject FAI rules real reason problems such wing its inherent weakness same true very thin wings biplane Shallow depth spars requires made hardwood wire interstrut bracing becomes truly functional Muffler pressure Reliable muffler pressure fuel tank necessity reducing change fuel flow between full emp ty tank have used silicone rubber tube tank filling plugged after filling seal against pressure loss plug prefer machine screw Too coarse thread 134 Model Aviation - sent us tne wrong oraer ana over stocke radios leading sellers Japan identical er 2 Circus 2 radios except label price ALPINAZ BEAT 2 STICK RADIO I
Edition: Model Aviation - 1986/07
Page Numbers: 38, 39, 40, 134
Lift Thrust Are Good DPAG EBill Layers weight distributed around 0 center gravity aircraft determines will react control inputs THRUST about hangar session 7much givesusmuchtothink about act upon V Drag WEIGHT Are Bad GUYSN THE COVERING plane shown drawings picture accounts 5i% models total weight fill fuel tank shifts center gravity CG forward just shade over three-quarters inch just couple things discovered recently decided learn about weight planes build see enjoy designing own planes Im inclined over-design build models too heavy strength really need figured Id go campaign reduce excess weight latest design weigh components went along truly enlightening experience yes pun intended though plane came out bit heavier hoped model has 1250 sq wing powered Supertigre 60 builtup structures conventional balsa Lite Ply plywood few pieces hard wood block illustrations show rest article about plane itself Its about should look weight reduction weight distribution ideas still provide enough strength high-stress areas Does mean RC models should lightened No design has its right recom mended weight give realistic performance penetration other desirable flight characteristics average guy like sometimes scratch-builds modi fies kits selects own materials components doing can easily overburden otherwise good design excess weightor weight misplaced Ill use model illustrated examples completed plane fuel weighs 9 lb 13 oz weighed major components some indi vidual parts well Built-up structures weighed before after covering Accuracy figures limited what could get household postal scales Numbers rounded off avoid com plication interested com parisons precision weight distribution chart shows percent weight major com ponent contributes total weight Well start looking numbers drawing some reasonable conclusions biggest part total weight wing29% Thats too surprising After going put airplane air fly wing what makes whole concept work other 71% hanging wings center sec tion structure better fail loop pull two Gs arithmetic tells wing will supporting 14 lb pullout almost fatal dive mightpull four Gs thatwould exert 28-lb pull wing 45-oz wing about right Actually thats issue Weight does mean strength Weight should very carefidly invested should invest weight dollars spend countsto strengthen high-stress points plane Conversely should minimize weight low-stress areas should invest weight wing answer good stout spars spar reinforcement plates center section Stress fuselagh-mounted wing like greatest center becomes progressively less toward tips lifting loads concentrated center transferred fuselage attachment points strut-supported wings J-3 Cub strut attachment points share burden center section center section doesnt have beefed up heavily such design strut attach ment points must also tough enough share course struts also add weight However airplane has tradeoffs strut-equipped plane tradeoff increased weight 38 Model Aviation LIFT models use heavy stuff hardwood plywood epoxy great strength needed Keep balance structure light good judgment will allow fuselage comes second 23% total weight ties other components together absorbs stresses Again invest wisely weight use strong heavy materials strength needed places needing lot tention attachment main land ing gear nose gear tail wheel Youve no doubt seen terrible loads taken landing gears upward sideways backward Toughen up attachment points way will oppose loads engine mount structure should stoutest areas model Normal stresses tough enough fuselage prop-first contacts ground create structural loads difficult measure Tail surface attachment points should tough lightweight Sport planes dont create heavy in-flight stresses tall higher airspeeds quicker maneuvers beefier points should means have adequate fuselage strength attaching wing example take note fact 71% planes weight hanging dear life onto three -20 nylon bolts fuse lage members thread power system accounting 16% weight ranks third includes engine muffler prop engine mount tank C-size onboard booster battery Im pleased figure especially find ST 60 alone accounted 8% weight Todays engines have high power-to-weight ratio dont think can gripe Im happy landing gear wheels struts tail wheel assem bly being 13% total item shocked tallied up numbers building plane just could carry around some wheels origi nal plans called 5-in wheels found weighed 1 lb 2 oz rushed back hobby shop traded smaller 4-in ones Ive got hedge bit complaint about weight wheels make lot touch-and-go landings like able taxi through rough terrain landing gear wheels take severe beatingbut still balk 13% Shop around select wheels isnt bad idea take postal scale Walt Good other pioneers permitted self-satisfied grin see 10% total weight fourservo airborne radio system Todays de signers manufacturers should com mended reliable durable lightweight sets market However area can save some weight shopping around comparing radio specifications Excellent airborne units offered have small lightweight receiv WING % PowIR LANDING 0GEAR 137 RADIO 10% Nsc 4 ers servos However dont use planes larger recommended RC equipment manufacturer completed tail assembly weighed just 7 oz 5% total Nothing really exciting Just try keep tail surfaces light adequate strength center section attachment points just like wing stresses concentrated Last list 4% miscellaneous Yes surprised figure ever miscellaneous weight can quickly add up hardware attaching engine mount landing gear wing tail packing attachments radio gear tail struts exhaust extension added afterthought etc Theres much can about miscellaneous pieces except analyze everything put Look ways saving ounces Ask yourself Can make special bracket out plywood instead metal Better yet can make out nylon Are weight distribution percent ages recommended ones No Im just reporting what found out about plane However recommend approach describe method alyzing own building methods selection materials components Would percentages same larger smaller planes Yes no Some weights would change almost pro portionately sizebuilt-up structures example Other items weight may change same way example four-servo Kraft radio would about 24% weight Falcon 56or 8% 9-ft J-3 Cub Thats enough about weight distribution Now commentator Paul Harvey would say youre goingto hear rest story~ point about weight distribution have contend center gravity CG locationand make fall right place Kits plans usually give fore-and-aft location some give acceptable range get right place main consideration wait until plane finished check out wait may have add ballast relocate radio gear possibly have change some pushrod July1986 39 author-designed model subject detailed weight analysis testing con ducted conclusions makethe old adage building lightness moreappropriate TIGER TAIL 45 DELHI ALL MLSA KIT An new Tiger Tail 120 four strokes Designed especial F3A Turn around competition balsa kit machined wood parts Hardware package includes plug-in adjustable stab parts new wing mounts Wing Span 72 inLength -60 Wing Nea 860 sq inWeight 8 lb Complete Delux Kit$15995 COMBO DEAL-Tiger Tail 4S Enyal2OR$395OO PUIS4N AIUSTASLE 51*3 KENT last can optmze stab nadence b fhght characteristics nair glass filled adjusters e included prourde micro screar adjustment smaller front tube Main tube atuminum nuts GP NEW WING MOINflING SE nung mounting system deaekped Ron Chidgey rs fad neat accurate stays tight Three aylon buckets screnus machined nuing blocht included $L95 See Your Dealer Order Direct Include $1 50 Per Item UPS GATOR R/C PRODUCTS 3713 Pompano Dnve 0 Pensacola FL 325140 Phorse 904 476-8639 Save Money lable semi-kit $1290 supply wood hardwarea-F As Featured $18900 Nlarch 86 RCM Magazine wing span44 wing area609 sq length56 weight65 lbs engine40-462 cycle radio4 channel Boa PARKINSON FLYING MODELS RRI Queens yule Ontario LOG iRO Canada Tel 416 478-2632 Z Please add $2000 ship handling Dealer Inquiries Invited lengths Its best determine receiver servo battery positions late con struction possible can shift weight elements back forth achieve correct balance position Theres locating CG should center plane right left CG isnt centered will forever trying trim out problem thatjust wont go away CG isnt centered left right check see have mounted heavy object side wing can culprit side has heavier material other must add weight lighter side wing small nails pieces solder imbedded tip can trick Better yet try weighing wing materials before assembly perhaps can achieve neutral balance build avoid later problem Theres Vhere vertical position CG should few plans define others just leave doubt doubt some things consider CG located well below center lift can provide pendulum effect type stability adds longitudinal stability keeps nose pitching up down improves lateral stability keeps plane roll ing right left heavy wheels must have brought CG down notch two right amount pendulum effect can enhance stability Tco much may overly stable may responsive controls would like plans dont define location will have consider type aircraft involved kind performance want Lets go off another tangent concentration weight Theoretically planes weight concentrated attheCGandlmeanall9lb l3ozthe plane would probably control line gang busters wouldnt able make hold still flight would change attitude slightest hint air turbulence control input An aircraft collection forces have balanced com promised other hand heavy items located extremities wing tips nose tail plane would sluggish reluctant change attitude planes dont fall either extreme tend toward latter case cant much about aircraft structures have weight best thing minimize weight extremities avoid ballasting can locate heavier items close can desired CG way youll have plane stable responsive controls Control surfaces also come scru tiny some planes high-speed situ ations flutter can tear up control surface structure supports way reduce possibility minimize weight aft hinge line greater Continued page 134 40 Model Aviation New GATOR High Performance Amphibian unique aircraft today has added line delta wing kits designed Laddie Mikulasko fully aerobetic off both water lend one-piece fiberglass fuselage cowl fairing wing-tip floats precision machine-cut foam delta wing assembles quickly easiiy4 02 lighter original balas version Unplug landing gear Iwater-tight nose wheel mount factory instailedl fly off water snow ice addition floats skils Stability wind penetration overall performance combined un believably low landing speed make Nffthstsr 2001 best designe yet kit has build test flown Laddie Mikulasko hia complete approval Two channel wheel radio unbeatable performance Servo reversing & end point adjustments both channels Continuously adjustable steering rate Adjustable steering wheel tension lncludes receiver switch harness battery holder Comes withwo JRS5O5 servos Available 2TMHz 9fLV An extremely reliable radio Two channel system cars boats lncludes battery case drycells receiver two JRS5O5 servos Available 27 MHz BOTH RADIOS ARE COVERED BY CIRCUS HOBBIES WARRANTY TAKE ADVANTAGE OF OUR ERROR AND SAVE WHILE SUPPLIES LAST PRICES SUBJECT TO CHANGE TED TO QUANTITY ON HAND CALL TOLL FREE NOW TO PLACE YOUR ORDER 800 782-0022 3132 S HIGHLAND DRIVE VEGAS NEVADA 89109 Radio Technique/Myers Continued page 131 tones pocket pager will almost always sound mushy AM perfectly clear FM Contact District Frequency Coordina tor information loan scanner name will found AMA News sec tion right under District VPs name picture dont know what district Look state listed above VP col umns AMA News George M Myers 70 Froehlich Farm Rd HicksvIIe NY 11801 Good-Bad/Layers Continued page 40 weight behind hinges greater problem becomes Ailerons seem especially susceptible Invest tough heavy materials areas take control surface stresses hinge points control horn mountings Keep rest structure light possible Static dynamic balancing topics another time selecting wood construction gen erally speaking high-density wood tougher heavier low-density wood weaker lighter Select wood its purpose regarding strength weight ailerons mentioned before prefer high-density wood sub-spar mounts hinges low-density trailing edge reduce weight aft hinge line Analyze structure youre building take time select proper materials Lets talk about covering may Strohs man happen MonoKote man covering planes past always felt type covering added undue amount weight pleased find covering accounted 5Yi% total weight came 9 oz5 wing 2 fuselage 1 tail Considering MonoKotes toughness great finish considerable amount strength adds built-up structures think terrific investment weight fact bargain havent tried everything shop around check manufacturers spec sheets weight conscious well color con scious about nice-to-have dontreally-need items some planes lug around plane have exhaust pipe extension keep plane little cleaner C-size onboard booster NiCd convenience Theyre nice have add 3 oz plane may have gone overboard first couple planes used tubular nylon pushrods soon convinced expansion contraction tem perature changes wanted put up Since Ive used hardwood dowel pushrods logic telling larger plane larger dowel should Too late correct now estimate four-dowel pushrods Y16 dia threaded rod ends weigh little dds up Ill have rethink last point wed best close hangar doors Design own planes Think youve got some neat ideas Well think huge windshield neat weighs about 2 oz Doesnt sound bad until call eighth pound thats weightand thats name game See Sunday RC Scale/Wischers Continued page 43 stable air course lack wind during its flights helped model its high placing scoring bonus undercam bered airfoil now debatable subject FAI rules real reason problems such wing its inherent weakness same true very thin wings biplane Shallow depth spars requires made hardwood wire interstrut bracing becomes truly functional Muffler pressure Reliable muffler pressure fuel tank necessity reducing change fuel flow between full emp ty tank have used silicone rubber tube tank filling plugged after filling seal against pressure loss plug prefer machine screw Too coarse thread 134 Model Aviation - sent us tne wrong oraer ana over stocke radios leading sellers Japan identical er 2 Circus 2 radios except label price ALPINAZ BEAT 2 STICK RADIO I
Edition: Model Aviation - 1986/07
Page Numbers: 38, 39, 40, 134
Lift Thrust Are Good DPAG EBill Layers weight distributed around 0 center gravity aircraft determines will react control inputs THRUST about hangar session 7much givesusmuchtothink about act upon V Drag WEIGHT Are Bad GUYSN THE COVERING plane shown drawings picture accounts 5i% models total weight fill fuel tank shifts center gravity CG forward just shade over three-quarters inch just couple things discovered recently decided learn about weight planes build see enjoy designing own planes Im inclined over-design build models too heavy strength really need figured Id go campaign reduce excess weight latest design weigh components went along truly enlightening experience yes pun intended though plane came out bit heavier hoped model has 1250 sq wing powered Supertigre 60 builtup structures conventional balsa Lite Ply plywood few pieces hard wood block illustrations show rest article about plane itself Its about should look weight reduction weight distribution ideas still provide enough strength high-stress areas Does mean RC models should lightened No design has its right recom mended weight give realistic performance penetration other desirable flight characteristics average guy like sometimes scratch-builds modi fies kits selects own materials components doing can easily overburden otherwise good design excess weightor weight misplaced Ill use model illustrated examples completed plane fuel weighs 9 lb 13 oz weighed major components some indi vidual parts well Built-up structures weighed before after covering Accuracy figures limited what could get household postal scales Numbers rounded off avoid com plication interested com parisons precision weight distribution chart shows percent weight major com ponent contributes total weight Well start looking numbers drawing some reasonable conclusions biggest part total weight wing29% Thats too surprising After going put airplane air fly wing what makes whole concept work other 71% hanging wings center sec tion structure better fail loop pull two Gs arithmetic tells wing will supporting 14 lb pullout almost fatal dive mightpull four Gs thatwould exert 28-lb pull wing 45-oz wing about right Actually thats issue Weight does mean strength Weight should very carefidly invested should invest weight dollars spend countsto strengthen high-stress points plane Conversely should minimize weight low-stress areas should invest weight wing answer good stout spars spar reinforcement plates center section Stress fuselagh-mounted wing like greatest center becomes progressively less toward tips lifting loads concentrated center transferred fuselage attachment points strut-supported wings J-3 Cub strut attachment points share burden center section center section doesnt have beefed up heavily such design strut attach ment points must also tough enough share course struts also add weight However airplane has tradeoffs strut-equipped plane tradeoff increased weight 38 Model Aviation LIFT models use heavy stuff hardwood plywood epoxy great strength needed Keep balance structure light good judgment will allow fuselage comes second 23% total weight ties other components together absorbs stresses Again invest wisely weight use strong heavy materials strength needed places needing lot tention attachment main land ing gear nose gear tail wheel Youve no doubt seen terrible loads taken landing gears upward sideways backward Toughen up attachment points way will oppose loads engine mount structure should stoutest areas model Normal stresses tough enough fuselage prop-first contacts ground create structural loads difficult measure Tail surface attachment points should tough lightweight Sport planes dont create heavy in-flight stresses tall higher airspeeds quicker maneuvers beefier points should means have adequate fuselage strength attaching wing example take note fact 71% planes weight hanging dear life onto three -20 nylon bolts fuse lage members thread power system accounting 16% weight ranks third includes engine muffler prop engine mount tank C-size onboard booster battery Im pleased figure especially find ST 60 alone accounted 8% weight Todays engines have high power-to-weight ratio dont think can gripe Im happy landing gear wheels struts tail wheel assem bly being 13% total item shocked tallied up numbers building plane just could carry around some wheels origi nal plans called 5-in wheels found weighed 1 lb 2 oz rushed back hobby shop traded smaller 4-in ones Ive got hedge bit complaint about weight wheels make lot touch-and-go landings like able taxi through rough terrain landing gear wheels take severe beatingbut still balk 13% Shop around select wheels isnt bad idea take postal scale Walt Good other pioneers permitted self-satisfied grin see 10% total weight fourservo airborne radio system Todays de signers manufacturers should com mended reliable durable lightweight sets market However area can save some weight shopping around comparing radio specifications Excellent airborne units offered have small lightweight receiv WING % PowIR LANDING 0GEAR 137 RADIO 10% Nsc 4 ers servos However dont use planes larger recommended RC equipment manufacturer completed tail assembly weighed just 7 oz 5% total Nothing really exciting Just try keep tail surfaces light adequate strength center section attachment points just like wing stresses concentrated Last list 4% miscellaneous Yes surprised figure ever miscellaneous weight can quickly add up hardware attaching engine mount landing gear wing tail packing attachments radio gear tail struts exhaust extension added afterthought etc Theres much can about miscellaneous pieces except analyze everything put Look ways saving ounces Ask yourself Can make special bracket out plywood instead metal Better yet can make out nylon Are weight distribution percent ages recommended ones No Im just reporting what found out about plane However recommend approach describe method alyzing own building methods selection materials components Would percentages same larger smaller planes Yes no Some weights would change almost pro portionately sizebuilt-up structures example Other items weight may change same way example four-servo Kraft radio would about 24% weight Falcon 56or 8% 9-ft J-3 Cub Thats enough about weight distribution Now commentator Paul Harvey would say youre goingto hear rest story~ point about weight distribution have contend center gravity CG locationand make fall right place Kits plans usually give fore-and-aft location some give acceptable range get right place main consideration wait until plane finished check out wait may have add ballast relocate radio gear possibly have change some pushrod July1986 39 author-designed model subject detailed weight analysis testing con ducted conclusions makethe old adage building lightness moreappropriate TIGER TAIL 45 DELHI ALL MLSA KIT An new Tiger Tail 120 four strokes Designed especial F3A Turn around competition balsa kit machined wood parts Hardware package includes plug-in adjustable stab parts new wing mounts Wing Span 72 inLength -60 Wing Nea 860 sq inWeight 8 lb Complete Delux Kit$15995 COMBO DEAL-Tiger Tail 4S Enyal2OR$395OO PUIS4N AIUSTASLE 51*3 KENT last can optmze stab nadence b fhght characteristics nair glass filled adjusters e included prourde micro screar adjustment smaller front tube Main tube atuminum nuts GP NEW WING MOINflING SE nung mounting system deaekped Ron Chidgey rs fad neat accurate stays tight Three aylon buckets screnus machined nuing blocht included $L95 See Your Dealer Order Direct Include $1 50 Per Item UPS GATOR R/C PRODUCTS 3713 Pompano Dnve 0 Pensacola FL 325140 Phorse 904 476-8639 Save Money lable semi-kit $1290 supply wood hardwarea-F As Featured $18900 Nlarch 86 RCM Magazine wing span44 wing area609 sq length56 weight65 lbs engine40-462 cycle radio4 channel Boa PARKINSON FLYING MODELS RRI Queens yule Ontario LOG iRO Canada Tel 416 478-2632 Z Please add $2000 ship handling Dealer Inquiries Invited lengths Its best determine receiver servo battery positions late con struction possible can shift weight elements back forth achieve correct balance position Theres locating CG should center plane right left CG isnt centered will forever trying trim out problem thatjust wont go away CG isnt centered left right check see have mounted heavy object side wing can culprit side has heavier material other must add weight lighter side wing small nails pieces solder imbedded tip can trick Better yet try weighing wing materials before assembly perhaps can achieve neutral balance build avoid later problem Theres Vhere vertical position CG should few plans define others just leave doubt doubt some things consider CG located well below center lift can provide pendulum effect type stability adds longitudinal stability keeps nose pitching up down improves lateral stability keeps plane roll ing right left heavy wheels must have brought CG down notch two right amount pendulum effect can enhance stability Tco much may overly stable may responsive controls would like plans dont define location will have consider type aircraft involved kind performance want Lets go off another tangent concentration weight Theoretically planes weight concentrated attheCGandlmeanall9lb l3ozthe plane would probably control line gang busters wouldnt able make hold still flight would change attitude slightest hint air turbulence control input An aircraft collection forces have balanced com promised other hand heavy items located extremities wing tips nose tail plane would sluggish reluctant change attitude planes dont fall either extreme tend toward latter case cant much about aircraft structures have weight best thing minimize weight extremities avoid ballasting can locate heavier items close can desired CG way youll have plane stable responsive controls Control surfaces also come scru tiny some planes high-speed situ ations flutter can tear up control surface structure supports way reduce possibility minimize weight aft hinge line greater Continued page 134 40 Model Aviation New GATOR High Performance Amphibian unique aircraft today has added line delta wing kits designed Laddie Mikulasko fully aerobetic off both water lend one-piece fiberglass fuselage cowl fairing wing-tip floats precision machine-cut foam delta wing assembles quickly easiiy4 02 lighter original balas version Unplug landing gear Iwater-tight nose wheel mount factory instailedl fly off water snow ice addition floats skils Stability wind penetration overall performance combined un believably low landing speed make Nffthstsr 2001 best designe yet kit has build test flown Laddie Mikulasko hia complete approval Two channel wheel radio unbeatable performance Servo reversing & end point adjustments both channels Continuously adjustable steering rate Adjustable steering wheel tension lncludes receiver switch harness battery holder Comes withwo JRS5O5 servos Available 2TMHz 9fLV An extremely reliable radio Two channel system cars boats lncludes battery case drycells receiver two JRS5O5 servos Available 27 MHz BOTH RADIOS ARE COVERED BY CIRCUS HOBBIES WARRANTY TAKE ADVANTAGE OF OUR ERROR AND SAVE WHILE SUPPLIES LAST PRICES SUBJECT TO CHANGE TED TO QUANTITY ON HAND CALL TOLL FREE NOW TO PLACE YOUR ORDER 800 782-0022 3132 S HIGHLAND DRIVE VEGAS NEVADA 89109 Radio Technique/Myers Continued page 131 tones pocket pager will almost always sound mushy AM perfectly clear FM Contact District Frequency Coordina tor information loan scanner name will found AMA News sec tion right under District VPs name picture dont know what district Look state listed above VP col umns AMA News George M Myers 70 Froehlich Farm Rd HicksvIIe NY 11801 Good-Bad/Layers Continued page 40 weight behind hinges greater problem becomes Ailerons seem especially susceptible Invest tough heavy materials areas take control surface stresses hinge points control horn mountings Keep rest structure light possible Static dynamic balancing topics another time selecting wood construction gen erally speaking high-density wood tougher heavier low-density wood weaker lighter Select wood its purpose regarding strength weight ailerons mentioned before prefer high-density wood sub-spar mounts hinges low-density trailing edge reduce weight aft hinge line Analyze structure youre building take time select proper materials Lets talk about covering may Strohs man happen MonoKote man covering planes past always felt type covering added undue amount weight pleased find covering accounted 5Yi% total weight came 9 oz5 wing 2 fuselage 1 tail Considering MonoKotes toughness great finish considerable amount strength adds built-up structures think terrific investment weight fact bargain havent tried everything shop around check manufacturers spec sheets weight conscious well color con scious about nice-to-have dontreally-need items some planes lug around plane have exhaust pipe extension keep plane little cleaner C-size onboard booster NiCd convenience Theyre nice have add 3 oz plane may have gone overboard first couple planes used tubular nylon pushrods soon convinced expansion contraction tem perature changes wanted put up Since Ive used hardwood dowel pushrods logic telling larger plane larger dowel should Too late correct now estimate four-dowel pushrods Y16 dia threaded rod ends weigh little dds up Ill have rethink last point wed best close hangar doors Design own planes Think youve got some neat ideas Well think huge windshield neat weighs about 2 oz Doesnt sound bad until call eighth pound thats weightand thats name game See Sunday RC Scale/Wischers Continued page 43 stable air course lack wind during its flights helped model its high placing scoring bonus undercam bered airfoil now debatable subject FAI rules real reason problems such wing its inherent weakness same true very thin wings biplane Shallow depth spars requires made hardwood wire interstrut bracing becomes truly functional Muffler pressure Reliable muffler pressure fuel tank necessity reducing change fuel flow between full emp ty tank have used silicone rubber tube tank filling plugged after filling seal against pressure loss plug prefer machine screw Too coarse thread 134 Model Aviation - sent us tne wrong oraer ana over stocke radios leading sellers Japan identical er 2 Circus 2 radios except label price ALPINAZ BEAT 2 STICK RADIO I