US MAIL cardboard] WHAT WOULD say told possible build semi-scale controlline model biplane 50-in wingspan less $10 material costs Well before say cant done take look pictures Douglas M-2 biplane model presented article because built less $10 material costs Sound interesting bet what can new wonder material Ill give few hints Its something see everyday probably have enough around house garage attic right now build large-sized model air plane Well before become candi date straitjacket Ill tell Its cardboard plain old /8-in corrugated cardboard can hear now Cardboard What can cardboard Well M 2 biplane just example poten tial cardboard possesses building ma terial Honestly could tell M-2 constructed cardboard looking photos finished model Dont feel bad couldnt because ex perienced modelers have stood five feet away M-2 realizing cardboard Which illustrates point cardboard models look bit good balsa models what about strength cardboard strong enough absorb beating model airplanes subjected other reasons using cardboard Well way answer let ask question shipping containers made corrugated card board balsa wood answer obvious cardboard box costs less can cut out piece folded together single strong unit balsa box would made separate pieces glued together cardboard box would take fraction time required build balsa box Now subject both boxes hard impact see what happens cardboard box may crease tear wind up hole could easily repaired cardboard insert patch What happens balsa box splinters cracks because balsa brittle Card board other hand non-brittle crushable material shock absorb ing Impacts absorbed locally transmitted throughout entire struc ture balsa box would heavier built strong enough absorb much impact cardboard box Also cardboard box ready painting soon glued together balsa box must sanded sealed before painting So advantages cardboard used example cardboard balsa box because something can understand compare intuitively same comparison still applies comparing two model airplane con struction materials Cardboard costs less cuts easily no cracking splitting large sections may formed continuous piece strong strong er balsa wood light weight resists damage requires no preparation painting ease cutting combined large shapes may formed 26 Model Aviation douglas m-2 scale-type controlliner quickly easily built Its sturdy can requires less $10 material costs Chuck Felton single piece cardboard have resulted simplified design techniques reduce building time absolute minimum As example wing M-2 con structed two pieces cardboard single spar two hours time both wings can built ready painting fuselage empennage have also designed easy fast building Now few words about cardboard technical term cardboard corrugated fiberboard specified test strength facing weight flute style its usual form consists outer facing paper inner flute paper inner facing paper Test strengths dependent weight three components specified pounds per thousand square feet Flute sizes B C result ap proximate thickness i/s 3/16 inches respectively material used M-2 model A-in 125-lb test-B flute lightest weight standard cardboard thickness However flying qualities model suffer use heavier cardboards includ ing 200-lb test board Sources card board virtually unlimited including department appliance stores Naturally cardboard cannot used models However M-2 clearly demonstrates cardboard can used wide variety applications both scale sport models Monoplanes bi planes triplanes equally easy build almost no additional cost model built scale 1 gives wingspan 50 inches wing area 750 square inches weight 3 pounds wing loading light results very shallow stable landing glide Slow realistic flight speeds attainable flat-bottom semi-diamond airfoil section results high lift low speeds enhances models stability handling qualities Engines 29 40 size can used model designed throttle con trol operation G-S Products 3-line bellcrank used specifically C22 ver sion conjunction G-S handle system proved excellent choice handles enlarged mechanism provides one-third power throttle control range results better speed control smooth action system also increases speed control addition bellcrank designed use clevis-type linkages clevis-type linkages used M-2 greatly simplified 3-line bellcrank installation highly recommend G-S Products system M-2 model just example what can achieved cardboard hope possibilities will stir interest enough try hand build ing M-2 cardboard airplane own design would welcome opportunity answer comments questions technique Just write following address Chuck Felton 10459 Artesia Blvd #72C Bellflower CA 90706 Construction Hints Glue Water-base glue such white glue Titebond recommended Con tact cement recommended since parts cannot shifted gluing sur faces Folding scoring fold lines done screening tool available hardware store consists handle 1 radiused wheel end run along straight edge fold line Finishing Cardboard gives solid sur face no open areas cover non-porous easiest method give three coats color dope two coats clear dope However wide variety finishing material can used card board Coverings such Solarfilm Mon okote vinyl paper can used recommended surface doped will result better bond Water Proofing Waterproofing card board quite simple can done October1977 27 Holding red-and-silver model Doug las M-2 Mailplane flown Western Air Ex press Chuck asks can tell made balsa five feet off found experienced modelers didnt note difference Left Wing spar ply landing gear mount glued piece bottom piece lower wing mount fits cutout cardboard spar crossing over Right Right wing top covering folded down glued place Fold lines accomplished screening tool 1-1/2 radius wheel Tool found hardware stores run along straightedge placed along fold lines Left Construction removable engine compartmenT natch evident consisting floor formers creasea top piece ix rigni compnmid ship ready painting Three coats colored dope two clear will suffice Solarfilm Monokote vinyl paper can used case surface should doped Before parts cut raw material can waterproofed mix 25% polyurethane 75% paint thinner Just brush allow dry 48 hours Cardboard cuts crisplylike wood 28 Model Aviation Len pruce slrlpsguuuu eu . rudder elevator hinge linesDrace carououru sorbang landing gear held ply mounting plate typical metal strap fittings Note drain tubes under nose Left 1-uselage construction negun Dy asyang pre-cum ceruuua us workb6,. orTitebond Riaht Firewall nlv motor mount doublers lock almost indestructible unit Use Left U-S Products 3-line balicrank C22 version mounted ply anchoreu uunurnn fuselage top rails 4oz clunk tank fastened ply floor rubberbands over paperclap hooks Engine compartment coated epoxy fuel-proofing compact arrangement Right Top pieces fit fuselage top rails flush top edges sides Note former place toward rear fuselage raw material before cut out parts aircraft Simply mix 25% clear polyurethane 75% paint thinner latter can cheapest hardware store variety thoroughly mixed clear polyurethane Brush mixture liberally cardboard sheet going use construc tion aircraft Allow soak through cardboard dry 48 hours adds no appreciable weight material renders cardboard completely waterproofed addition start cut treated card board will find crisp wood cuts sharply cleanly Construction Cut out cardboard wood parts using template outlines sure note direction corrugations Score fold cardboard parts indicated plans Stabilizer Fin Glue pruce strips stabilizer trailing edge elevator leading edge Round off edges spruce pieces smooth control surface movement Hinge elevator stabilizer cloth hinges four places Fill raw edges cardboard glue Glue X spruce strips fin trailing edge rudder leading edge Rudder glued fin rudder trailing edge offset ide flying circle Fill raw edges cardboard glue Wing Begin wings making two wing spars Spars /8 X /e balsa strip capped spruce strips top bottom bottom wing made left- right-hand wing panel cut out centerline plywood gear support Glue two panels together along bottom centerline Glue ply gear mount cutout Glue wing spar place tip spar 3A sq balsa cut triangular shape Scrap cardboard doublers glued ply gear mount overlap surrounding cardboard Glue 1 oz weight right wing tip Ap ply glue top wing spar wing trail ing edge Fold wing over weigh down until dry Seal wing trailing edge centerline joint gummed paper tape Fill wing tip raw edges glue Top wing Continued page 81 EDITORS NOTE Because creasing interest corrugated card board building material ar ticle recommended reading RC people well CL builders article transcends construction M-2interesting itself cluding informative briefing material valuable construction hints prior how-to-build portion article glue folding finishing water-proofing S I I 2 [0 -ifi 0H 016I 0 Iti S Ij2 100 rc 00 0 0 iL Op p 00p 00 0 - I 0 I FULL-SIZE PLANSAVAILABLESEE PAGE 96 N z Ow Oi 0004 00 00 plo 00 00 S October 1977 29
Edition: Model Aviation - 1977/10
Page Numbers: 26, 27, 28, 29
US MAIL cardboard] WHAT WOULD say told possible build semi-scale controlline model biplane 50-in wingspan less $10 material costs Well before say cant done take look pictures Douglas M-2 biplane model presented article because built less $10 material costs Sound interesting bet what can new wonder material Ill give few hints Its something see everyday probably have enough around house garage attic right now build large-sized model air plane Well before become candi date straitjacket Ill tell Its cardboard plain old /8-in corrugated cardboard can hear now Cardboard What can cardboard Well M 2 biplane just example poten tial cardboard possesses building ma terial Honestly could tell M-2 constructed cardboard looking photos finished model Dont feel bad couldnt because ex perienced modelers have stood five feet away M-2 realizing cardboard Which illustrates point cardboard models look bit good balsa models what about strength cardboard strong enough absorb beating model airplanes subjected other reasons using cardboard Well way answer let ask question shipping containers made corrugated card board balsa wood answer obvious cardboard box costs less can cut out piece folded together single strong unit balsa box would made separate pieces glued together cardboard box would take fraction time required build balsa box Now subject both boxes hard impact see what happens cardboard box may crease tear wind up hole could easily repaired cardboard insert patch What happens balsa box splinters cracks because balsa brittle Card board other hand non-brittle crushable material shock absorb ing Impacts absorbed locally transmitted throughout entire struc ture balsa box would heavier built strong enough absorb much impact cardboard box Also cardboard box ready painting soon glued together balsa box must sanded sealed before painting So advantages cardboard used example cardboard balsa box because something can understand compare intuitively same comparison still applies comparing two model airplane con struction materials Cardboard costs less cuts easily no cracking splitting large sections may formed continuous piece strong strong er balsa wood light weight resists damage requires no preparation painting ease cutting combined large shapes may formed 26 Model Aviation douglas m-2 scale-type controlliner quickly easily built Its sturdy can requires less $10 material costs Chuck Felton single piece cardboard have resulted simplified design techniques reduce building time absolute minimum As example wing M-2 con structed two pieces cardboard single spar two hours time both wings can built ready painting fuselage empennage have also designed easy fast building Now few words about cardboard technical term cardboard corrugated fiberboard specified test strength facing weight flute style its usual form consists outer facing paper inner flute paper inner facing paper Test strengths dependent weight three components specified pounds per thousand square feet Flute sizes B C result ap proximate thickness i/s 3/16 inches respectively material used M-2 model A-in 125-lb test-B flute lightest weight standard cardboard thickness However flying qualities model suffer use heavier cardboards includ ing 200-lb test board Sources card board virtually unlimited including department appliance stores Naturally cardboard cannot used models However M-2 clearly demonstrates cardboard can used wide variety applications both scale sport models Monoplanes bi planes triplanes equally easy build almost no additional cost model built scale 1 gives wingspan 50 inches wing area 750 square inches weight 3 pounds wing loading light results very shallow stable landing glide Slow realistic flight speeds attainable flat-bottom semi-diamond airfoil section results high lift low speeds enhances models stability handling qualities Engines 29 40 size can used model designed throttle con trol operation G-S Products 3-line bellcrank used specifically C22 ver sion conjunction G-S handle system proved excellent choice handles enlarged mechanism provides one-third power throttle control range results better speed control smooth action system also increases speed control addition bellcrank designed use clevis-type linkages clevis-type linkages used M-2 greatly simplified 3-line bellcrank installation highly recommend G-S Products system M-2 model just example what can achieved cardboard hope possibilities will stir interest enough try hand build ing M-2 cardboard airplane own design would welcome opportunity answer comments questions technique Just write following address Chuck Felton 10459 Artesia Blvd #72C Bellflower CA 90706 Construction Hints Glue Water-base glue such white glue Titebond recommended Con tact cement recommended since parts cannot shifted gluing sur faces Folding scoring fold lines done screening tool available hardware store consists handle 1 radiused wheel end run along straight edge fold line Finishing Cardboard gives solid sur face no open areas cover non-porous easiest method give three coats color dope two coats clear dope However wide variety finishing material can used card board Coverings such Solarfilm Mon okote vinyl paper can used recommended surface doped will result better bond Water Proofing Waterproofing card board quite simple can done October1977 27 Holding red-and-silver model Doug las M-2 Mailplane flown Western Air Ex press Chuck asks can tell made balsa five feet off found experienced modelers didnt note difference Left Wing spar ply landing gear mount glued piece bottom piece lower wing mount fits cutout cardboard spar crossing over Right Right wing top covering folded down glued place Fold lines accomplished screening tool 1-1/2 radius wheel Tool found hardware stores run along straightedge placed along fold lines Left Construction removable engine compartmenT natch evident consisting floor formers creasea top piece ix rigni compnmid ship ready painting Three coats colored dope two clear will suffice Solarfilm Monokote vinyl paper can used case surface should doped Before parts cut raw material can waterproofed mix 25% polyurethane 75% paint thinner Just brush allow dry 48 hours Cardboard cuts crisplylike wood 28 Model Aviation Len pruce slrlpsguuuu eu . rudder elevator hinge linesDrace carououru sorbang landing gear held ply mounting plate typical metal strap fittings Note drain tubes under nose Left 1-uselage construction negun Dy asyang pre-cum ceruuua us workb6,. orTitebond Riaht Firewall nlv motor mount doublers lock almost indestructible unit Use Left U-S Products 3-line balicrank C22 version mounted ply anchoreu uunurnn fuselage top rails 4oz clunk tank fastened ply floor rubberbands over paperclap hooks Engine compartment coated epoxy fuel-proofing compact arrangement Right Top pieces fit fuselage top rails flush top edges sides Note former place toward rear fuselage raw material before cut out parts aircraft Simply mix 25% clear polyurethane 75% paint thinner latter can cheapest hardware store variety thoroughly mixed clear polyurethane Brush mixture liberally cardboard sheet going use construc tion aircraft Allow soak through cardboard dry 48 hours adds no appreciable weight material renders cardboard completely waterproofed addition start cut treated card board will find crisp wood cuts sharply cleanly Construction Cut out cardboard wood parts using template outlines sure note direction corrugations Score fold cardboard parts indicated plans Stabilizer Fin Glue pruce strips stabilizer trailing edge elevator leading edge Round off edges spruce pieces smooth control surface movement Hinge elevator stabilizer cloth hinges four places Fill raw edges cardboard glue Glue X spruce strips fin trailing edge rudder leading edge Rudder glued fin rudder trailing edge offset ide flying circle Fill raw edges cardboard glue Wing Begin wings making two wing spars Spars /8 X /e balsa strip capped spruce strips top bottom bottom wing made left- right-hand wing panel cut out centerline plywood gear support Glue two panels together along bottom centerline Glue ply gear mount cutout Glue wing spar place tip spar 3A sq balsa cut triangular shape Scrap cardboard doublers glued ply gear mount overlap surrounding cardboard Glue 1 oz weight right wing tip Ap ply glue top wing spar wing trail ing edge Fold wing over weigh down until dry Seal wing trailing edge centerline joint gummed paper tape Fill wing tip raw edges glue Top wing Continued page 81 EDITORS NOTE Because creasing interest corrugated card board building material ar ticle recommended reading RC people well CL builders article transcends construction M-2interesting itself cluding informative briefing material valuable construction hints prior how-to-build portion article glue folding finishing water-proofing S I I 2 [0 -ifi 0H 016I 0 Iti S Ij2 100 rc 00 0 0 iL Op p 00p 00 0 - I 0 I FULL-SIZE PLANSAVAILABLESEE PAGE 96 N z Ow Oi 0004 00 00 plo 00 00 S October 1977 29
Edition: Model Aviation - 1977/10
Page Numbers: 26, 27, 28, 29
US MAIL cardboard] WHAT WOULD say told possible build semi-scale controlline model biplane 50-in wingspan less $10 material costs Well before say cant done take look pictures Douglas M-2 biplane model presented article because built less $10 material costs Sound interesting bet what can new wonder material Ill give few hints Its something see everyday probably have enough around house garage attic right now build large-sized model air plane Well before become candi date straitjacket Ill tell Its cardboard plain old /8-in corrugated cardboard can hear now Cardboard What can cardboard Well M 2 biplane just example poten tial cardboard possesses building ma terial Honestly could tell M-2 constructed cardboard looking photos finished model Dont feel bad couldnt because ex perienced modelers have stood five feet away M-2 realizing cardboard Which illustrates point cardboard models look bit good balsa models what about strength cardboard strong enough absorb beating model airplanes subjected other reasons using cardboard Well way answer let ask question shipping containers made corrugated card board balsa wood answer obvious cardboard box costs less can cut out piece folded together single strong unit balsa box would made separate pieces glued together cardboard box would take fraction time required build balsa box Now subject both boxes hard impact see what happens cardboard box may crease tear wind up hole could easily repaired cardboard insert patch What happens balsa box splinters cracks because balsa brittle Card board other hand non-brittle crushable material shock absorb ing Impacts absorbed locally transmitted throughout entire struc ture balsa box would heavier built strong enough absorb much impact cardboard box Also cardboard box ready painting soon glued together balsa box must sanded sealed before painting So advantages cardboard used example cardboard balsa box because something can understand compare intuitively same comparison still applies comparing two model airplane con struction materials Cardboard costs less cuts easily no cracking splitting large sections may formed continuous piece strong strong er balsa wood light weight resists damage requires no preparation painting ease cutting combined large shapes may formed 26 Model Aviation douglas m-2 scale-type controlliner quickly easily built Its sturdy can requires less $10 material costs Chuck Felton single piece cardboard have resulted simplified design techniques reduce building time absolute minimum As example wing M-2 con structed two pieces cardboard single spar two hours time both wings can built ready painting fuselage empennage have also designed easy fast building Now few words about cardboard technical term cardboard corrugated fiberboard specified test strength facing weight flute style its usual form consists outer facing paper inner flute paper inner facing paper Test strengths dependent weight three components specified pounds per thousand square feet Flute sizes B C result ap proximate thickness i/s 3/16 inches respectively material used M-2 model A-in 125-lb test-B flute lightest weight standard cardboard thickness However flying qualities model suffer use heavier cardboards includ ing 200-lb test board Sources card board virtually unlimited including department appliance stores Naturally cardboard cannot used models However M-2 clearly demonstrates cardboard can used wide variety applications both scale sport models Monoplanes bi planes triplanes equally easy build almost no additional cost model built scale 1 gives wingspan 50 inches wing area 750 square inches weight 3 pounds wing loading light results very shallow stable landing glide Slow realistic flight speeds attainable flat-bottom semi-diamond airfoil section results high lift low speeds enhances models stability handling qualities Engines 29 40 size can used model designed throttle con trol operation G-S Products 3-line bellcrank used specifically C22 ver sion conjunction G-S handle system proved excellent choice handles enlarged mechanism provides one-third power throttle control range results better speed control smooth action system also increases speed control addition bellcrank designed use clevis-type linkages clevis-type linkages used M-2 greatly simplified 3-line bellcrank installation highly recommend G-S Products system M-2 model just example what can achieved cardboard hope possibilities will stir interest enough try hand build ing M-2 cardboard airplane own design would welcome opportunity answer comments questions technique Just write following address Chuck Felton 10459 Artesia Blvd #72C Bellflower CA 90706 Construction Hints Glue Water-base glue such white glue Titebond recommended Con tact cement recommended since parts cannot shifted gluing sur faces Folding scoring fold lines done screening tool available hardware store consists handle 1 radiused wheel end run along straight edge fold line Finishing Cardboard gives solid sur face no open areas cover non-porous easiest method give three coats color dope two coats clear dope However wide variety finishing material can used card board Coverings such Solarfilm Mon okote vinyl paper can used recommended surface doped will result better bond Water Proofing Waterproofing card board quite simple can done October1977 27 Holding red-and-silver model Doug las M-2 Mailplane flown Western Air Ex press Chuck asks can tell made balsa five feet off found experienced modelers didnt note difference Left Wing spar ply landing gear mount glued piece bottom piece lower wing mount fits cutout cardboard spar crossing over Right Right wing top covering folded down glued place Fold lines accomplished screening tool 1-1/2 radius wheel Tool found hardware stores run along straightedge placed along fold lines Left Construction removable engine compartmenT natch evident consisting floor formers creasea top piece ix rigni compnmid ship ready painting Three coats colored dope two clear will suffice Solarfilm Monokote vinyl paper can used case surface should doped Before parts cut raw material can waterproofed mix 25% polyurethane 75% paint thinner Just brush allow dry 48 hours Cardboard cuts crisplylike wood 28 Model Aviation Len pruce slrlpsguuuu eu . rudder elevator hinge linesDrace carououru sorbang landing gear held ply mounting plate typical metal strap fittings Note drain tubes under nose Left 1-uselage construction negun Dy asyang pre-cum ceruuua us workb6,. orTitebond Riaht Firewall nlv motor mount doublers lock almost indestructible unit Use Left U-S Products 3-line balicrank C22 version mounted ply anchoreu uunurnn fuselage top rails 4oz clunk tank fastened ply floor rubberbands over paperclap hooks Engine compartment coated epoxy fuel-proofing compact arrangement Right Top pieces fit fuselage top rails flush top edges sides Note former place toward rear fuselage raw material before cut out parts aircraft Simply mix 25% clear polyurethane 75% paint thinner latter can cheapest hardware store variety thoroughly mixed clear polyurethane Brush mixture liberally cardboard sheet going use construc tion aircraft Allow soak through cardboard dry 48 hours adds no appreciable weight material renders cardboard completely waterproofed addition start cut treated card board will find crisp wood cuts sharply cleanly Construction Cut out cardboard wood parts using template outlines sure note direction corrugations Score fold cardboard parts indicated plans Stabilizer Fin Glue pruce strips stabilizer trailing edge elevator leading edge Round off edges spruce pieces smooth control surface movement Hinge elevator stabilizer cloth hinges four places Fill raw edges cardboard glue Glue X spruce strips fin trailing edge rudder leading edge Rudder glued fin rudder trailing edge offset ide flying circle Fill raw edges cardboard glue Wing Begin wings making two wing spars Spars /8 X /e balsa strip capped spruce strips top bottom bottom wing made left- right-hand wing panel cut out centerline plywood gear support Glue two panels together along bottom centerline Glue ply gear mount cutout Glue wing spar place tip spar 3A sq balsa cut triangular shape Scrap cardboard doublers glued ply gear mount overlap surrounding cardboard Glue 1 oz weight right wing tip Ap ply glue top wing spar wing trail ing edge Fold wing over weigh down until dry Seal wing trailing edge centerline joint gummed paper tape Fill wing tip raw edges glue Top wing Continued page 81 EDITORS NOTE Because creasing interest corrugated card board building material ar ticle recommended reading RC people well CL builders article transcends construction M-2interesting itself cluding informative briefing material valuable construction hints prior how-to-build portion article glue folding finishing water-proofing S I I 2 [0 -ifi 0H 016I 0 Iti S Ij2 100 rc 00 0 0 iL Op p 00p 00 0 - I 0 I FULL-SIZE PLANSAVAILABLESEE PAGE 96 N z Ow Oi 0004 00 00 plo 00 00 S October 1977 29
Edition: Model Aviation - 1977/10
Page Numbers: 26, 27, 28, 29
US MAIL cardboard] WHAT WOULD say told possible build semi-scale controlline model biplane 50-in wingspan less $10 material costs Well before say cant done take look pictures Douglas M-2 biplane model presented article because built less $10 material costs Sound interesting bet what can new wonder material Ill give few hints Its something see everyday probably have enough around house garage attic right now build large-sized model air plane Well before become candi date straitjacket Ill tell Its cardboard plain old /8-in corrugated cardboard can hear now Cardboard What can cardboard Well M 2 biplane just example poten tial cardboard possesses building ma terial Honestly could tell M-2 constructed cardboard looking photos finished model Dont feel bad couldnt because ex perienced modelers have stood five feet away M-2 realizing cardboard Which illustrates point cardboard models look bit good balsa models what about strength cardboard strong enough absorb beating model airplanes subjected other reasons using cardboard Well way answer let ask question shipping containers made corrugated card board balsa wood answer obvious cardboard box costs less can cut out piece folded together single strong unit balsa box would made separate pieces glued together cardboard box would take fraction time required build balsa box Now subject both boxes hard impact see what happens cardboard box may crease tear wind up hole could easily repaired cardboard insert patch What happens balsa box splinters cracks because balsa brittle Card board other hand non-brittle crushable material shock absorb ing Impacts absorbed locally transmitted throughout entire struc ture balsa box would heavier built strong enough absorb much impact cardboard box Also cardboard box ready painting soon glued together balsa box must sanded sealed before painting So advantages cardboard used example cardboard balsa box because something can understand compare intuitively same comparison still applies comparing two model airplane con struction materials Cardboard costs less cuts easily no cracking splitting large sections may formed continuous piece strong strong er balsa wood light weight resists damage requires no preparation painting ease cutting combined large shapes may formed 26 Model Aviation douglas m-2 scale-type controlliner quickly easily built Its sturdy can requires less $10 material costs Chuck Felton single piece cardboard have resulted simplified design techniques reduce building time absolute minimum As example wing M-2 con structed two pieces cardboard single spar two hours time both wings can built ready painting fuselage empennage have also designed easy fast building Now few words about cardboard technical term cardboard corrugated fiberboard specified test strength facing weight flute style its usual form consists outer facing paper inner flute paper inner facing paper Test strengths dependent weight three components specified pounds per thousand square feet Flute sizes B C result ap proximate thickness i/s 3/16 inches respectively material used M-2 model A-in 125-lb test-B flute lightest weight standard cardboard thickness However flying qualities model suffer use heavier cardboards includ ing 200-lb test board Sources card board virtually unlimited including department appliance stores Naturally cardboard cannot used models However M-2 clearly demonstrates cardboard can used wide variety applications both scale sport models Monoplanes bi planes triplanes equally easy build almost no additional cost model built scale 1 gives wingspan 50 inches wing area 750 square inches weight 3 pounds wing loading light results very shallow stable landing glide Slow realistic flight speeds attainable flat-bottom semi-diamond airfoil section results high lift low speeds enhances models stability handling qualities Engines 29 40 size can used model designed throttle con trol operation G-S Products 3-line bellcrank used specifically C22 ver sion conjunction G-S handle system proved excellent choice handles enlarged mechanism provides one-third power throttle control range results better speed control smooth action system also increases speed control addition bellcrank designed use clevis-type linkages clevis-type linkages used M-2 greatly simplified 3-line bellcrank installation highly recommend G-S Products system M-2 model just example what can achieved cardboard hope possibilities will stir interest enough try hand build ing M-2 cardboard airplane own design would welcome opportunity answer comments questions technique Just write following address Chuck Felton 10459 Artesia Blvd #72C Bellflower CA 90706 Construction Hints Glue Water-base glue such white glue Titebond recommended Con tact cement recommended since parts cannot shifted gluing sur faces Folding scoring fold lines done screening tool available hardware store consists handle 1 radiused wheel end run along straight edge fold line Finishing Cardboard gives solid sur face no open areas cover non-porous easiest method give three coats color dope two coats clear dope However wide variety finishing material can used card board Coverings such Solarfilm Mon okote vinyl paper can used recommended surface doped will result better bond Water Proofing Waterproofing card board quite simple can done October1977 27 Holding red-and-silver model Doug las M-2 Mailplane flown Western Air Ex press Chuck asks can tell made balsa five feet off found experienced modelers didnt note difference Left Wing spar ply landing gear mount glued piece bottom piece lower wing mount fits cutout cardboard spar crossing over Right Right wing top covering folded down glued place Fold lines accomplished screening tool 1-1/2 radius wheel Tool found hardware stores run along straightedge placed along fold lines Left Construction removable engine compartmenT natch evident consisting floor formers creasea top piece ix rigni compnmid ship ready painting Three coats colored dope two clear will suffice Solarfilm Monokote vinyl paper can used case surface should doped Before parts cut raw material can waterproofed mix 25% polyurethane 75% paint thinner Just brush allow dry 48 hours Cardboard cuts crisplylike wood 28 Model Aviation Len pruce slrlpsguuuu eu . rudder elevator hinge linesDrace carououru sorbang landing gear held ply mounting plate typical metal strap fittings Note drain tubes under nose Left 1-uselage construction negun Dy asyang pre-cum ceruuua us workb6,. orTitebond Riaht Firewall nlv motor mount doublers lock almost indestructible unit Use Left U-S Products 3-line balicrank C22 version mounted ply anchoreu uunurnn fuselage top rails 4oz clunk tank fastened ply floor rubberbands over paperclap hooks Engine compartment coated epoxy fuel-proofing compact arrangement Right Top pieces fit fuselage top rails flush top edges sides Note former place toward rear fuselage raw material before cut out parts aircraft Simply mix 25% clear polyurethane 75% paint thinner latter can cheapest hardware store variety thoroughly mixed clear polyurethane Brush mixture liberally cardboard sheet going use construc tion aircraft Allow soak through cardboard dry 48 hours adds no appreciable weight material renders cardboard completely waterproofed addition start cut treated card board will find crisp wood cuts sharply cleanly Construction Cut out cardboard wood parts using template outlines sure note direction corrugations Score fold cardboard parts indicated plans Stabilizer Fin Glue pruce strips stabilizer trailing edge elevator leading edge Round off edges spruce pieces smooth control surface movement Hinge elevator stabilizer cloth hinges four places Fill raw edges cardboard glue Glue X spruce strips fin trailing edge rudder leading edge Rudder glued fin rudder trailing edge offset ide flying circle Fill raw edges cardboard glue Wing Begin wings making two wing spars Spars /8 X /e balsa strip capped spruce strips top bottom bottom wing made left- right-hand wing panel cut out centerline plywood gear support Glue two panels together along bottom centerline Glue ply gear mount cutout Glue wing spar place tip spar 3A sq balsa cut triangular shape Scrap cardboard doublers glued ply gear mount overlap surrounding cardboard Glue 1 oz weight right wing tip Ap ply glue top wing spar wing trail ing edge Fold wing over weigh down until dry Seal wing trailing edge centerline joint gummed paper tape Fill wing tip raw edges glue Top wing Continued page 81 EDITORS NOTE Because creasing interest corrugated card board building material ar ticle recommended reading RC people well CL builders article transcends construction M-2interesting itself cluding informative briefing material valuable construction hints prior how-to-build portion article glue folding finishing water-proofing S I I 2 [0 -ifi 0H 016I 0 Iti S Ij2 100 rc 00 0 0 iL Op p 00p 00 0 - I 0 I FULL-SIZE PLANSAVAILABLESEE PAGE 96 N z Ow Oi 0004 00 00 plo 00 00 S October 1977 29