Control Line Scale Bill Boss CG OR NOT CG question appears some basic CL model-building con cepts/techniques seem worth repeat ing time time such topic suggest ed Steve Tift Midland TX concerns bellcrank its positioning respect models center gravity CG also place lead-out wires within below above models wingtip addi tion Steves also received requests couple modelers have involved RC Scale modeling some time now turning CL Scale have also asked about basics bellcrank installation have answered individually thought might appropriate share some comments col umn Perhaps others reading col umn new Control Line flying could use same basic information Lets start question belicrank place ment regard models center grav ity believe rule pretty simple bellcrank should located immediate vicin ity center gravity reason stat ing rule did because believe location critical might think have talked CL builders about problem have found slight variation location either ahead behind CG has little effect models performance Lets put some measurements varia tion model has wingspan about 60 believe mounting bellcrank inch either side CG makes much difference its flying performance However smaller models say 30-in wing span would make effort observe CG position best could Next lets turn another factor equally important mounting position bellcrank balancing model Placement bellcrank really will much you dont balance model properly after finished Notice said balance after model finished reason during course finishing model add paint details end other model balanced before painting might just add enough paint tail section upset balance Once again CG point model should balanced Dont afraid add lead nose tail achieve wellbalanced model Experience among Scale modelers has indicated model moderately nose-heavy far better slightest bit tall-heavy photos months column show some good examples models present various problems balance C-47 F4F Wildcat have relatively short nose moment arms respect CG position will undoubtedly require addition consider able amount nose weight achieve balance Curtiss AT-9 Jeep model depending weight engines used may require nose weight could fact require some tail weight accomplish balance large engine nacelles landing gear engines add considerable weight forward CG tail assembly rear fuselage structure small comparatively less weighty Pitts 52A model thatwhen com pleted engine installed 35 larger will because type structure close balanced might require addition weight either end does weight added will minimal Dont forget position bellcrank near CG above balance model nothing frightening get lat est project alr first time find either flies tail down hunterand nothing handle end seems able correct flight atti tude thing left pray get model back ground piece what should have done before balance Next month well discuss placement lead-outs handle lead-outs above below wing Tip Workshop W Rozelle says next bending landing gears next least favorite model-building chore messing fiberglass cloth Cutting straight line all-but-impossible task finally get cut starts raveling halfway through its application model surface brush starts pick up bits yarn etc Rozelle goes say fiberglass cloth can made easy handle following simple procedure First spread some news papers workshop floor Next place waxed paper top newspaper covering large enough area spread fiberglass cloth Lay out fiberglass cloth using heavy objects weight down edges cloth straighten out Work cloth go along get threads straight across overall piece cloth square cloth held firmly place spray lightly nitrate dope let dry com pletely Note Use ample ventilation during spraying operation nitrate dope will stabilize cloth allowing roll up much like would roll up piece tissue Cutting will now pleasure will able cut pieces exact size shape after marking cloth felt-tip pen Application stiffened cloth will course much easier can depending using cloth user thinner over predoped nitrate butyrate surface epoxy etc nitrate dope used stiffen set fiberglass cloth because compatible undercoat overcoat finishing products See Palnt Filler Sealer com Continued page 154 68 Model Aviation PiUs S-2A John Patroila Marshtleld MA isa great-looking CL Precision Scale model won fourth atthe 1985 Nats Columnist Bill Boss uses modelas well asall others inthe photosas examples models either easy difficult balance Bill Reynolas installing flying prop Grumman F4F Wildcat after static judging atthe Buckeye AZ Reglonals complet ed Models such AT-9 Jeep C-47 present some unique prob lem month R Baltes plc Bill Hibbltts fuels Douglas C-47 model suffered some minor damage engine quit takeoff Another scene Buckeye Roland Baites lasttlme saw Curtiss AT 9 Jeep model Bill Oldham type model presents some very distinct problems balance proper flying char acteristics AT-9 used during WW II train P-38 pilots Photo R Baltes EASY TO BUILD HANDCRAFTED KITS AT LOW PRICES 3g spanWeigni OsWing span s Wing span WeIght 4 lOs Length 53 inEngine 60 -90Length 45 inEngine 45 -60Length 48 inEngine 40 Kits include Pre-built fiberglass fuselage foam cores sheeted balsa machine cut balsa tail surfaces shaped strip ailerons complete hardware pack SEND CHECK OR MONEY ORDER TOVISA & MASTER CARD ACCEPTED W HORIZON MODELS INC T-404 Kelly Ave Manchester NH 03103 603 627-9503 indoors club meeting won trophy strong belch would throw off course terminal tail slide airfoil shown should very generally allow better penetration turbulence pro vide superior glide somewhat durable could increase mo tor tube length believe would appreciably enhance performance V-dihedral has tried have taller pylons neither added much except struc tural problems heart design low aspect ratio wing very slow prop/rubber combination opposed tra ditional out-of-sight climb/glide mode uppermost thought fun pursuit toward worthwhile goal uncon ventional point view hope build fly project will extract same pleasure did 154 Model Aviation CL Scale/Boss Continued page 68 patibility chart May 1985 column stiffened cloth will easier work will look much neater threads will straighter instead wavy squirrelly look cant avoid using standard application method item W Rozelle found Wing Tips Newsletter Mid-Hudson Mod elmasters courtesy SAM re printed Corsair Mini-contest report Roland Baltes San Pedro CA reports Southwestern Regionals held Buckeye AZ once seeing fair turnout CL Sport Scale event years event held January entry nine models four twin-engine types Weather good temperature Seventies wind minimum excellent day Scale flying Some months photos Roland Buckeye entries Roland commented nine entries may seem like much happening area hasnt seen Scale meet over year turnout nine considered fairly good Roland expects next years contest hopes able report another good increase activity Please send correspondenceand espe cially photosrelating CL Scale Bill Boss 77-06 269th St New Hyde Park NY 11040 CL Aerobatics/Fancher Continued page 69 other maneuver Square Eight helped aft center gravity wind Because planes speed increase opens up corners tough keep maneuver right size As mentioned last month horse power maneuver strong engine will worth its weight gold maintaining line ten sion resisting speed increases hint havent great engine make maneuver tall narrow spend less time try ing penetrate wind wont perfect will able complete recogniza able Eight calm air move backwards during top horizontal leg thus allowing critical areas bottom corners intersectionto flown free wake turbulence Also avoid hit ting corners hard calm high drag results will sap airspeed horse power weak engine can run out steam long difficult Square Eight Whipping couple laps prior entry will build up little stored energy good air Vertical Eight quite easy can find cloud 450 use inter sections simply fly two perfect loops top other wind up becomes lot tougher way up never let fuselage get hori zontal intersection does will never get top loop round right size against wind Reverse control just before path airplane starts descend regardless its body angle Once get top consciously apply Down control maintain radius outside loop make intersection wind blows down exception rule never seeing body angle tangent intersection before reversing control Allow flight path just stop descending before giv ing Up complete Eight Try avoid non-pro look climbing inverted inter section relatively painless calm-air maneu ver step two just past intersection way up should enough Hourglass probably mistreated maneuvers almost fliers make same errors As Triangle first corner turned too far resulting climb angles far off fliers right second error often combination first mak ing top leg parallel bottom Both er rors result plane being position impossible complete maneu ver acceptably either front behind directly over head flier solution addition horsepower first error stop first corner just flying correct Triangle resulting climb steep slightly infl fl P55 PS flflPS PS PS PS PS S PS PS 4 VIDEO i Special Summer Rates June tbru August Only Rentals 1y 1195 Any 2 2300 All Tape Purchases 10% OFF - - Retail - 1 Basic Construction Beginners 107 Mm 49 95 42 Basic Flight Training Beginners 65 Mm44 95 3 World Model Aniarion 90 Mm 44 95 4 Oshkosh Onerviess 55Mm 3995 5Airplane Funnies 30 Mm39 95 61JS Scln Masters 60 Mm4195 Action 75 Mm 4995 dge Hoppin Vol 145 Mm 41 95 4 9 Which Wag Up 70 Mm 47954 K lOHedga Hoppin Vol 1140 Mm 4195 4 Rental Depositm Retail Price Tape 4 K Rental Dnratlnnm 7 Days After Del lueryK K Payment Chech 110 daysl MO Visa/M C Card # & 4 4 Eup Date Phone # C OD u Anailahle hy Phone4 K Shippingm 375 Foreign Canada Add 10% Total 4 4 Others 15% IL Res Add 7% Tan4 KAcademy AvIatIon R & D PO Boo 2774 4Hazel Crest IL 60428 335-07764 4.4
Edition: Model Aviation - 1986/08
Page Numbers: 68, 154
Control Line Scale Bill Boss CG OR NOT CG question appears some basic CL model-building con cepts/techniques seem worth repeat ing time time such topic suggest ed Steve Tift Midland TX concerns bellcrank its positioning respect models center gravity CG also place lead-out wires within below above models wingtip addi tion Steves also received requests couple modelers have involved RC Scale modeling some time now turning CL Scale have also asked about basics bellcrank installation have answered individually thought might appropriate share some comments col umn Perhaps others reading col umn new Control Line flying could use same basic information Lets start question belicrank place ment regard models center grav ity believe rule pretty simple bellcrank should located immediate vicin ity center gravity reason stat ing rule did because believe location critical might think have talked CL builders about problem have found slight variation location either ahead behind CG has little effect models performance Lets put some measurements varia tion model has wingspan about 60 believe mounting bellcrank inch either side CG makes much difference its flying performance However smaller models say 30-in wing span would make effort observe CG position best could Next lets turn another factor equally important mounting position bellcrank balancing model Placement bellcrank really will much you dont balance model properly after finished Notice said balance after model finished reason during course finishing model add paint details end other model balanced before painting might just add enough paint tail section upset balance Once again CG point model should balanced Dont afraid add lead nose tail achieve wellbalanced model Experience among Scale modelers has indicated model moderately nose-heavy far better slightest bit tall-heavy photos months column show some good examples models present various problems balance C-47 F4F Wildcat have relatively short nose moment arms respect CG position will undoubtedly require addition consider able amount nose weight achieve balance Curtiss AT-9 Jeep model depending weight engines used may require nose weight could fact require some tail weight accomplish balance large engine nacelles landing gear engines add considerable weight forward CG tail assembly rear fuselage structure small comparatively less weighty Pitts 52A model thatwhen com pleted engine installed 35 larger will because type structure close balanced might require addition weight either end does weight added will minimal Dont forget position bellcrank near CG above balance model nothing frightening get lat est project alr first time find either flies tail down hunterand nothing handle end seems able correct flight atti tude thing left pray get model back ground piece what should have done before balance Next month well discuss placement lead-outs handle lead-outs above below wing Tip Workshop W Rozelle says next bending landing gears next least favorite model-building chore messing fiberglass cloth Cutting straight line all-but-impossible task finally get cut starts raveling halfway through its application model surface brush starts pick up bits yarn etc Rozelle goes say fiberglass cloth can made easy handle following simple procedure First spread some news papers workshop floor Next place waxed paper top newspaper covering large enough area spread fiberglass cloth Lay out fiberglass cloth using heavy objects weight down edges cloth straighten out Work cloth go along get threads straight across overall piece cloth square cloth held firmly place spray lightly nitrate dope let dry com pletely Note Use ample ventilation during spraying operation nitrate dope will stabilize cloth allowing roll up much like would roll up piece tissue Cutting will now pleasure will able cut pieces exact size shape after marking cloth felt-tip pen Application stiffened cloth will course much easier can depending using cloth user thinner over predoped nitrate butyrate surface epoxy etc nitrate dope used stiffen set fiberglass cloth because compatible undercoat overcoat finishing products See Palnt Filler Sealer com Continued page 154 68 Model Aviation PiUs S-2A John Patroila Marshtleld MA isa great-looking CL Precision Scale model won fourth atthe 1985 Nats Columnist Bill Boss uses modelas well asall others inthe photosas examples models either easy difficult balance Bill Reynolas installing flying prop Grumman F4F Wildcat after static judging atthe Buckeye AZ Reglonals complet ed Models such AT-9 Jeep C-47 present some unique prob lem month R Baltes plc Bill Hibbltts fuels Douglas C-47 model suffered some minor damage engine quit takeoff Another scene Buckeye Roland Baites lasttlme saw Curtiss AT 9 Jeep model Bill Oldham type model presents some very distinct problems balance proper flying char acteristics AT-9 used during WW II train P-38 pilots Photo R Baltes EASY TO BUILD HANDCRAFTED KITS AT LOW PRICES 3g spanWeigni OsWing span s Wing span WeIght 4 lOs Length 53 inEngine 60 -90Length 45 inEngine 45 -60Length 48 inEngine 40 Kits include Pre-built fiberglass fuselage foam cores sheeted balsa machine cut balsa tail surfaces shaped strip ailerons complete hardware pack SEND CHECK OR MONEY ORDER TOVISA & MASTER CARD ACCEPTED W HORIZON MODELS INC T-404 Kelly Ave Manchester NH 03103 603 627-9503 indoors club meeting won trophy strong belch would throw off course terminal tail slide airfoil shown should very generally allow better penetration turbulence pro vide superior glide somewhat durable could increase mo tor tube length believe would appreciably enhance performance V-dihedral has tried have taller pylons neither added much except struc tural problems heart design low aspect ratio wing very slow prop/rubber combination opposed tra ditional out-of-sight climb/glide mode uppermost thought fun pursuit toward worthwhile goal uncon ventional point view hope build fly project will extract same pleasure did 154 Model Aviation CL Scale/Boss Continued page 68 patibility chart May 1985 column stiffened cloth will easier work will look much neater threads will straighter instead wavy squirrelly look cant avoid using standard application method item W Rozelle found Wing Tips Newsletter Mid-Hudson Mod elmasters courtesy SAM re printed Corsair Mini-contest report Roland Baltes San Pedro CA reports Southwestern Regionals held Buckeye AZ once seeing fair turnout CL Sport Scale event years event held January entry nine models four twin-engine types Weather good temperature Seventies wind minimum excellent day Scale flying Some months photos Roland Buckeye entries Roland commented nine entries may seem like much happening area hasnt seen Scale meet over year turnout nine considered fairly good Roland expects next years contest hopes able report another good increase activity Please send correspondenceand espe cially photosrelating CL Scale Bill Boss 77-06 269th St New Hyde Park NY 11040 CL Aerobatics/Fancher Continued page 69 other maneuver Square Eight helped aft center gravity wind Because planes speed increase opens up corners tough keep maneuver right size As mentioned last month horse power maneuver strong engine will worth its weight gold maintaining line ten sion resisting speed increases hint havent great engine make maneuver tall narrow spend less time try ing penetrate wind wont perfect will able complete recogniza able Eight calm air move backwards during top horizontal leg thus allowing critical areas bottom corners intersectionto flown free wake turbulence Also avoid hit ting corners hard calm high drag results will sap airspeed horse power weak engine can run out steam long difficult Square Eight Whipping couple laps prior entry will build up little stored energy good air Vertical Eight quite easy can find cloud 450 use inter sections simply fly two perfect loops top other wind up becomes lot tougher way up never let fuselage get hori zontal intersection does will never get top loop round right size against wind Reverse control just before path airplane starts descend regardless its body angle Once get top consciously apply Down control maintain radius outside loop make intersection wind blows down exception rule never seeing body angle tangent intersection before reversing control Allow flight path just stop descending before giv ing Up complete Eight Try avoid non-pro look climbing inverted inter section relatively painless calm-air maneu ver step two just past intersection way up should enough Hourglass probably mistreated maneuvers almost fliers make same errors As Triangle first corner turned too far resulting climb angles far off fliers right second error often combination first mak ing top leg parallel bottom Both er rors result plane being position impossible complete maneu ver acceptably either front behind directly over head flier solution addition horsepower first error stop first corner just flying correct Triangle resulting climb steep slightly infl fl P55 PS flflPS PS PS PS PS S PS PS 4 VIDEO i Special Summer Rates June tbru August Only Rentals 1y 1195 Any 2 2300 All Tape Purchases 10% OFF - - Retail - 1 Basic Construction Beginners 107 Mm 49 95 42 Basic Flight Training Beginners 65 Mm44 95 3 World Model Aniarion 90 Mm 44 95 4 Oshkosh Onerviess 55Mm 3995 5Airplane Funnies 30 Mm39 95 61JS Scln Masters 60 Mm4195 Action 75 Mm 4995 dge Hoppin Vol 145 Mm 41 95 4 9 Which Wag Up 70 Mm 47954 K lOHedga Hoppin Vol 1140 Mm 4195 4 Rental Depositm Retail Price Tape 4 K Rental Dnratlnnm 7 Days After Del lueryK K Payment Chech 110 daysl MO Visa/M C Card # & 4 4 Eup Date Phone # C OD u Anailahle hy Phone4 K Shippingm 375 Foreign Canada Add 10% Total 4 4 Others 15% IL Res Add 7% Tan4 KAcademy AvIatIon R & D PO Boo 2774 4Hazel Crest IL 60428 335-07764 4.4