II 'I Editors note As Part Gil Morris handled technical review piece have included comments appropriate IN THIS PART actual structural designs will illustrated based engineering principle outlined Part locating material far neutral axis possible Consider inflight forces involved various aircraft components fuselage wing horizontal vertical tail surfaces landing gear powered RC models fuselage probably heavily stressed item Photo 1 must absorb thrust torque loads engine bending loads weights engine receiver servos battery rudder elevator action twisting loads ailerons operated exaggerated centrifugal loads model banks pulls out dive pulls up sharply fuselage-mounted landing gear either tricycle tail-dragger imposes heavy loads particularly hard landings best overall structure fuselage cylindersuitably reinforced cutouts wings canopy etc involved Such rounded fuselage difficult produce fiberglass epoxy Photo 2 made way far neutral axis possible philosophy closely followed few bulkheads required balsa such structure calls laborious planking practice square rectangular cross-section well-rounded corners much practical Photo 1 illustrates balsa stressed structuresimple yet strong increasing size triangular corner stock larger corner radii possible thickness balsa sheet governed models size models 15 power can use A6 sheet up 45 use 3A2 sheet larger use 1/ sheet wing has absorb lift drag torsion loads airfoils pitching moment except symmetrical sections aileron action tending twist wingtips opposite directions forces may amplified several times centrifugal forces g forces aircraft maneuvers High-lift devices such flaps tend twist wing Any structure wing should close outside airfoil profile spanwise spar spars withstand bending loads should located point maximum thickness airfoil flaps ailerons involved smaller spanwise spar will support local flap aileron August1994 53 I I II I Srucura D~sign Photo 4 loads Morris A shear web joining major load-bearing members vital structure yet cannot outside airfoil must inside Photo 2 shows cross-section wing model up seven inches chord outer AB skin absorbs lift twisting drag loads small spar ahead ailerons flaps latter skinned 1/32 balsa sheet have 1/ balsa aileron spar Photo 3 shows structure wing 40-45 model Note spars spar webs economy balsa 1As skip may omitted between front rear spars could replaced capstrips Photo 4 wing center section shown four-point bolting transfers torsion lift load fuselage itself strengthened wing structure Photo 5 Rib spacing 2Y2 3/2 inches will provide adequate support usually divide semi-span out inboard end ailerons number equal spaces Outboard aileron root similarly divided rib spacing may larger inboard position since stresses lower same spacing applies horizontal vertical tailplanes models up 12 inches chord 1A6 thick balsa skins provide adequate strength spanwise spars chords greater 7 inches chords beyond 12 inches 3A2 balsa skins suggested Horizontal tail surfaces composed stabilizer elevators hinged stab rear edge should double surfaced instead solid balsa better streamlining greater strength less weight Structure similar wing required Elevators should similarly double surfaced light leading edge spar vertical tail surfaces fin rudder allow same principle horizontal surface However T-tail involved fin structure will require additional spar must very stiff absorb horizontal tail loads Small models can use /32 balsa sheeting tail surfaces always surprises few pieces flimsy balsa sheet can provide relatively strong warp-free structure Early stabilizer elevator cross-sections 40-sized model used A2 balsa reinforcing spars plastic hinges Current structures use 1/16 balsa sheet light Figure 1 NOEB CALiii11111111 jIjGRA N OR~ OR 2 BEAMOFFSET WEBBOX BEAM TYRCAL WING SPAR CONSTRUOTtON OFTALS Figure 2 spars stab trailing edge elevator leading edge simpler build rugged Hinging double MonoKote also used rudder ailerons provides strong hinge gap seal greater control effectiveness Photo 6 shows cross section flying boat fin rudder T tall Note spars web Tapering wing horizontal vertical tails will permit stronger surfaces Obviously tapered wing will have root depth spar considerably larger straight wing same area wing section permits 54 Model Aviation o 3 Photo 5 Photo 6 Photo 8 _Il HARD II 0 BEND FNG BALSA SHEET Photo 7 Mini Glue TipsAdd 20% ftIoder 4for$1lO Tee Good Stuff Bar Design Corporation $310 fOr 11 L3/Box 3384 Torrance CA 90510$465 22 Mini Saw $1000 $310 GLOW FUEL MANUFACTURED WITH THE PUREST FINEST QUALITY INGREDIENTS AVAILABLE Superior Igniters- Improve starting idle acceleration Youll notice power bargain fuels * Special Detergents- Promote clean burning prevent residue buildup * Rust Inhibitors Protect engines corrosion After-run oil needed engines * Film Strength Additives- Increase lubricity provide extra lean run protection * Anti-Wear Additives Help keep engines running peak performance * Satisfaction Guaranteed SIG CHAMPION 2-STROKE FUEL PINT QUART GALLON 0% Nitromethane $1095 5% Nitromethane $350 $535 $1395 10% Nitromethane $425 $575 $1595 15% Nitromethane $425 $675 $1795 25% Nitromethane $535 $855 $2395 35% Nitromethane $640 $950 $2895 SIG CHAMPION 4-STROKE FUEL 10% Nitromethane 15% Nitromethane SIG ALL-CASTOR FUEL 5% Nitromethane 20% CASTOR $1395 10% Nitromethane 20% CASTOR $1595 15% Nitromethane 20% CASTOR $1795 5% Nitromethane 25% CASTOR $1495 10% Nitromethane 25% CASTOR $1695 SIG SIGNATURE FUEL Signature Fuel FREE SHIPPING ON ORDERS OVER $1500 BUT ALL ORDERS ARE SUBJECT TO $700/Pkg UPS HAZARDOUS MATERIAL SURCHARGE Prices subject change notice Toll Free Orders 800-2475008 FAX 515-623-3922 Modelers Hotline 800-524-7805 SIG MANUFACTURING CO INCMontezuma IA 50171 lighter structure particularly spars tapered example spar upper flange 1/2 X 1/4 12-inch root chord can reduced 1/4 X /s eight-inch tip chord addition increased spar depth wing skins further neutral axis root adding wings strength point greater stress thus permitting higher aspect-ratio wings Similar comments apply vertical horizontal tailplanes Tapered surfaces have drawbacks however tips will operate lower Reynolds numbers lower efficiency danger wingtip stall rib being different increases time design structure Construction complex Landing gear Photo 7 illustrates infuselage 5A2 music wire arrangement 40-powered model parallel sides wire U form torsion bars absorb landing loads plywood bulkheads also support wing loads Photo 8 illustrates arrangement bolted-on aluminum sheet landing gear Osprey ood built fuselage structure wing lowwing involved absorbs loads 20 T nuts secured plywood anchor bolts Bolts nylon /4-20 fillister head Balsa sheet readily bent across grainparticularly softened liquid ammoniabut easily bent along grain Figure 1 Balsa sheet resists shear strongly across grain wood hut weak shear along grain Thus spar webs designed resist shear should have grain running flange flange Figure 2 Balsa wing flap aileron skins should have grain parallel span adds strength bending resists shear generated torsion fuselage structure grain best parallel centerline can see no advantage having bottom sheeting grain across fuselage acts like shear web fuselage sides flanges provides added strength sideways bending under rudder action weakens fuselage far torsion loads aileron action up-anddown bending loads elevator action both forces substantially higher rudder action cutouts wing canopy need reinforced internal doublers should provided fuselagemounted bolted-on aluminum landing gear odel Aviation Stuff $140 per sheet LArLOftO Stay Tray $210 // Mipi nndqr
Edition: Model Aviation - 1994/08
Page Numbers: 53, 54, 56
II 'I Editors note As Part Gil Morris handled technical review piece have included comments appropriate IN THIS PART actual structural designs will illustrated based engineering principle outlined Part locating material far neutral axis possible Consider inflight forces involved various aircraft components fuselage wing horizontal vertical tail surfaces landing gear powered RC models fuselage probably heavily stressed item Photo 1 must absorb thrust torque loads engine bending loads weights engine receiver servos battery rudder elevator action twisting loads ailerons operated exaggerated centrifugal loads model banks pulls out dive pulls up sharply fuselage-mounted landing gear either tricycle tail-dragger imposes heavy loads particularly hard landings best overall structure fuselage cylindersuitably reinforced cutouts wings canopy etc involved Such rounded fuselage difficult produce fiberglass epoxy Photo 2 made way far neutral axis possible philosophy closely followed few bulkheads required balsa such structure calls laborious planking practice square rectangular cross-section well-rounded corners much practical Photo 1 illustrates balsa stressed structuresimple yet strong increasing size triangular corner stock larger corner radii possible thickness balsa sheet governed models size models 15 power can use A6 sheet up 45 use 3A2 sheet larger use 1/ sheet wing has absorb lift drag torsion loads airfoils pitching moment except symmetrical sections aileron action tending twist wingtips opposite directions forces may amplified several times centrifugal forces g forces aircraft maneuvers High-lift devices such flaps tend twist wing Any structure wing should close outside airfoil profile spanwise spar spars withstand bending loads should located point maximum thickness airfoil flaps ailerons involved smaller spanwise spar will support local flap aileron August1994 53 I I II I Srucura D~sign Photo 4 loads Morris A shear web joining major load-bearing members vital structure yet cannot outside airfoil must inside Photo 2 shows cross-section wing model up seven inches chord outer AB skin absorbs lift twisting drag loads small spar ahead ailerons flaps latter skinned 1/32 balsa sheet have 1/ balsa aileron spar Photo 3 shows structure wing 40-45 model Note spars spar webs economy balsa 1As skip may omitted between front rear spars could replaced capstrips Photo 4 wing center section shown four-point bolting transfers torsion lift load fuselage itself strengthened wing structure Photo 5 Rib spacing 2Y2 3/2 inches will provide adequate support usually divide semi-span out inboard end ailerons number equal spaces Outboard aileron root similarly divided rib spacing may larger inboard position since stresses lower same spacing applies horizontal vertical tailplanes models up 12 inches chord 1A6 thick balsa skins provide adequate strength spanwise spars chords greater 7 inches chords beyond 12 inches 3A2 balsa skins suggested Horizontal tail surfaces composed stabilizer elevators hinged stab rear edge should double surfaced instead solid balsa better streamlining greater strength less weight Structure similar wing required Elevators should similarly double surfaced light leading edge spar vertical tail surfaces fin rudder allow same principle horizontal surface However T-tail involved fin structure will require additional spar must very stiff absorb horizontal tail loads Small models can use /32 balsa sheeting tail surfaces always surprises few pieces flimsy balsa sheet can provide relatively strong warp-free structure Early stabilizer elevator cross-sections 40-sized model used A2 balsa reinforcing spars plastic hinges Current structures use 1/16 balsa sheet light Figure 1 NOEB CALiii11111111 jIjGRA N OR~ OR 2 BEAMOFFSET WEBBOX BEAM TYRCAL WING SPAR CONSTRUOTtON OFTALS Figure 2 spars stab trailing edge elevator leading edge simpler build rugged Hinging double MonoKote also used rudder ailerons provides strong hinge gap seal greater control effectiveness Photo 6 shows cross section flying boat fin rudder T tall Note spars web Tapering wing horizontal vertical tails will permit stronger surfaces Obviously tapered wing will have root depth spar considerably larger straight wing same area wing section permits 54 Model Aviation o 3 Photo 5 Photo 6 Photo 8 _Il HARD II 0 BEND FNG BALSA SHEET Photo 7 Mini Glue TipsAdd 20% ftIoder 4for$1lO Tee Good Stuff Bar Design Corporation $310 fOr 11 L3/Box 3384 Torrance CA 90510$465 22 Mini Saw $1000 $310 GLOW FUEL MANUFACTURED WITH THE PUREST FINEST QUALITY INGREDIENTS AVAILABLE Superior Igniters- Improve starting idle acceleration Youll notice power bargain fuels * Special Detergents- Promote clean burning prevent residue buildup * Rust Inhibitors Protect engines corrosion After-run oil needed engines * Film Strength Additives- Increase lubricity provide extra lean run protection * Anti-Wear Additives Help keep engines running peak performance * Satisfaction Guaranteed SIG CHAMPION 2-STROKE FUEL PINT QUART GALLON 0% Nitromethane $1095 5% Nitromethane $350 $535 $1395 10% Nitromethane $425 $575 $1595 15% Nitromethane $425 $675 $1795 25% Nitromethane $535 $855 $2395 35% Nitromethane $640 $950 $2895 SIG CHAMPION 4-STROKE FUEL 10% Nitromethane 15% Nitromethane SIG ALL-CASTOR FUEL 5% Nitromethane 20% CASTOR $1395 10% Nitromethane 20% CASTOR $1595 15% Nitromethane 20% CASTOR $1795 5% Nitromethane 25% CASTOR $1495 10% Nitromethane 25% CASTOR $1695 SIG SIGNATURE FUEL Signature Fuel FREE SHIPPING ON ORDERS OVER $1500 BUT ALL ORDERS ARE SUBJECT TO $700/Pkg UPS HAZARDOUS MATERIAL SURCHARGE Prices subject change notice Toll Free Orders 800-2475008 FAX 515-623-3922 Modelers Hotline 800-524-7805 SIG MANUFACTURING CO INCMontezuma IA 50171 lighter structure particularly spars tapered example spar upper flange 1/2 X 1/4 12-inch root chord can reduced 1/4 X /s eight-inch tip chord addition increased spar depth wing skins further neutral axis root adding wings strength point greater stress thus permitting higher aspect-ratio wings Similar comments apply vertical horizontal tailplanes Tapered surfaces have drawbacks however tips will operate lower Reynolds numbers lower efficiency danger wingtip stall rib being different increases time design structure Construction complex Landing gear Photo 7 illustrates infuselage 5A2 music wire arrangement 40-powered model parallel sides wire U form torsion bars absorb landing loads plywood bulkheads also support wing loads Photo 8 illustrates arrangement bolted-on aluminum sheet landing gear Osprey ood built fuselage structure wing lowwing involved absorbs loads 20 T nuts secured plywood anchor bolts Bolts nylon /4-20 fillister head Balsa sheet readily bent across grainparticularly softened liquid ammoniabut easily bent along grain Figure 1 Balsa sheet resists shear strongly across grain wood hut weak shear along grain Thus spar webs designed resist shear should have grain running flange flange Figure 2 Balsa wing flap aileron skins should have grain parallel span adds strength bending resists shear generated torsion fuselage structure grain best parallel centerline can see no advantage having bottom sheeting grain across fuselage acts like shear web fuselage sides flanges provides added strength sideways bending under rudder action weakens fuselage far torsion loads aileron action up-anddown bending loads elevator action both forces substantially higher rudder action cutouts wing canopy need reinforced internal doublers should provided fuselagemounted bolted-on aluminum landing gear odel Aviation Stuff $140 per sheet LArLOftO Stay Tray $210 // Mipi nndqr
Edition: Model Aviation - 1994/08
Page Numbers: 53, 54, 56
II 'I Editors note As Part Gil Morris handled technical review piece have included comments appropriate IN THIS PART actual structural designs will illustrated based engineering principle outlined Part locating material far neutral axis possible Consider inflight forces involved various aircraft components fuselage wing horizontal vertical tail surfaces landing gear powered RC models fuselage probably heavily stressed item Photo 1 must absorb thrust torque loads engine bending loads weights engine receiver servos battery rudder elevator action twisting loads ailerons operated exaggerated centrifugal loads model banks pulls out dive pulls up sharply fuselage-mounted landing gear either tricycle tail-dragger imposes heavy loads particularly hard landings best overall structure fuselage cylindersuitably reinforced cutouts wings canopy etc involved Such rounded fuselage difficult produce fiberglass epoxy Photo 2 made way far neutral axis possible philosophy closely followed few bulkheads required balsa such structure calls laborious planking practice square rectangular cross-section well-rounded corners much practical Photo 1 illustrates balsa stressed structuresimple yet strong increasing size triangular corner stock larger corner radii possible thickness balsa sheet governed models size models 15 power can use A6 sheet up 45 use 3A2 sheet larger use 1/ sheet wing has absorb lift drag torsion loads airfoils pitching moment except symmetrical sections aileron action tending twist wingtips opposite directions forces may amplified several times centrifugal forces g forces aircraft maneuvers High-lift devices such flaps tend twist wing Any structure wing should close outside airfoil profile spanwise spar spars withstand bending loads should located point maximum thickness airfoil flaps ailerons involved smaller spanwise spar will support local flap aileron August1994 53 I I II I Srucura D~sign Photo 4 loads Morris A shear web joining major load-bearing members vital structure yet cannot outside airfoil must inside Photo 2 shows cross-section wing model up seven inches chord outer AB skin absorbs lift twisting drag loads small spar ahead ailerons flaps latter skinned 1/32 balsa sheet have 1/ balsa aileron spar Photo 3 shows structure wing 40-45 model Note spars spar webs economy balsa 1As skip may omitted between front rear spars could replaced capstrips Photo 4 wing center section shown four-point bolting transfers torsion lift load fuselage itself strengthened wing structure Photo 5 Rib spacing 2Y2 3/2 inches will provide adequate support usually divide semi-span out inboard end ailerons number equal spaces Outboard aileron root similarly divided rib spacing may larger inboard position since stresses lower same spacing applies horizontal vertical tailplanes models up 12 inches chord 1A6 thick balsa skins provide adequate strength spanwise spars chords greater 7 inches chords beyond 12 inches 3A2 balsa skins suggested Horizontal tail surfaces composed stabilizer elevators hinged stab rear edge should double surfaced instead solid balsa better streamlining greater strength less weight Structure similar wing required Elevators should similarly double surfaced light leading edge spar vertical tail surfaces fin rudder allow same principle horizontal surface However T-tail involved fin structure will require additional spar must very stiff absorb horizontal tail loads Small models can use /32 balsa sheeting tail surfaces always surprises few pieces flimsy balsa sheet can provide relatively strong warp-free structure Early stabilizer elevator cross-sections 40-sized model used A2 balsa reinforcing spars plastic hinges Current structures use 1/16 balsa sheet light Figure 1 NOEB CALiii11111111 jIjGRA N OR~ OR 2 BEAMOFFSET WEBBOX BEAM TYRCAL WING SPAR CONSTRUOTtON OFTALS Figure 2 spars stab trailing edge elevator leading edge simpler build rugged Hinging double MonoKote also used rudder ailerons provides strong hinge gap seal greater control effectiveness Photo 6 shows cross section flying boat fin rudder T tall Note spars web Tapering wing horizontal vertical tails will permit stronger surfaces Obviously tapered wing will have root depth spar considerably larger straight wing same area wing section permits 54 Model Aviation o 3 Photo 5 Photo 6 Photo 8 _Il HARD II 0 BEND FNG BALSA SHEET Photo 7 Mini Glue TipsAdd 20% ftIoder 4for$1lO Tee Good Stuff Bar Design Corporation $310 fOr 11 L3/Box 3384 Torrance CA 90510$465 22 Mini Saw $1000 $310 GLOW FUEL MANUFACTURED WITH THE PUREST FINEST QUALITY INGREDIENTS AVAILABLE Superior Igniters- Improve starting idle acceleration Youll notice power bargain fuels * Special Detergents- Promote clean burning prevent residue buildup * Rust Inhibitors Protect engines corrosion After-run oil needed engines * Film Strength Additives- Increase lubricity provide extra lean run protection * Anti-Wear Additives Help keep engines running peak performance * Satisfaction Guaranteed SIG CHAMPION 2-STROKE FUEL PINT QUART GALLON 0% Nitromethane $1095 5% Nitromethane $350 $535 $1395 10% Nitromethane $425 $575 $1595 15% Nitromethane $425 $675 $1795 25% Nitromethane $535 $855 $2395 35% Nitromethane $640 $950 $2895 SIG CHAMPION 4-STROKE FUEL 10% Nitromethane 15% Nitromethane SIG ALL-CASTOR FUEL 5% Nitromethane 20% CASTOR $1395 10% Nitromethane 20% CASTOR $1595 15% Nitromethane 20% CASTOR $1795 5% Nitromethane 25% CASTOR $1495 10% Nitromethane 25% CASTOR $1695 SIG SIGNATURE FUEL Signature Fuel FREE SHIPPING ON ORDERS OVER $1500 BUT ALL ORDERS ARE SUBJECT TO $700/Pkg UPS HAZARDOUS MATERIAL SURCHARGE Prices subject change notice Toll Free Orders 800-2475008 FAX 515-623-3922 Modelers Hotline 800-524-7805 SIG MANUFACTURING CO INCMontezuma IA 50171 lighter structure particularly spars tapered example spar upper flange 1/2 X 1/4 12-inch root chord can reduced 1/4 X /s eight-inch tip chord addition increased spar depth wing skins further neutral axis root adding wings strength point greater stress thus permitting higher aspect-ratio wings Similar comments apply vertical horizontal tailplanes Tapered surfaces have drawbacks however tips will operate lower Reynolds numbers lower efficiency danger wingtip stall rib being different increases time design structure Construction complex Landing gear Photo 7 illustrates infuselage 5A2 music wire arrangement 40-powered model parallel sides wire U form torsion bars absorb landing loads plywood bulkheads also support wing loads Photo 8 illustrates arrangement bolted-on aluminum sheet landing gear Osprey ood built fuselage structure wing lowwing involved absorbs loads 20 T nuts secured plywood anchor bolts Bolts nylon /4-20 fillister head Balsa sheet readily bent across grainparticularly softened liquid ammoniabut easily bent along grain Figure 1 Balsa sheet resists shear strongly across grain wood hut weak shear along grain Thus spar webs designed resist shear should have grain running flange flange Figure 2 Balsa wing flap aileron skins should have grain parallel span adds strength bending resists shear generated torsion fuselage structure grain best parallel centerline can see no advantage having bottom sheeting grain across fuselage acts like shear web fuselage sides flanges provides added strength sideways bending under rudder action weakens fuselage far torsion loads aileron action up-anddown bending loads elevator action both forces substantially higher rudder action cutouts wing canopy need reinforced internal doublers should provided fuselagemounted bolted-on aluminum landing gear odel Aviation Stuff $140 per sheet LArLOftO Stay Tray $210 // Mipi nndqr