FREE FLIGHT SPORT SCALE Im going discuss couple areas construction hope will find informative useful first involves sheeting fuselage represent metal full-size aircraft Often smaller Rubber scale model stringers used instead sheeting doesnt look nearly good other option seen frequently use stringers balsa sandwiched between uillow opinion least desirable smooth contour virtually impossible because of glue joints glue being harder balsa doesnt allow uniform sanding know some glues sand pretty well problem still exists can get sheeting looks good doesnt create weight penalty Folkerts SK3 shown weighs 191 grams 68 ounces fuselage length 19 inches Thats bad considering much better fuselage looks appropriate sheeting top bottom sheeting have compound curves both made sheet balsa Read see its done Another photo shows piece StyrofoamTM has contoured fit between two bulkheads firewall cockpit will become mold sorts make use piece 1/16 balsa sheet will become floor mold sheet will have shape fuselage viewed top Balsa bulkheads cut proper shape dictated plan glued end sheet StyrofoamTM cut fit between floor two bulkheads assembly glued place StyrofoamTM sanded proper contour Choose lightest piece 1/16 balsa sheet large enough wrap over foam soak water several hours important because want wood supple possible may wonder use 1/i2 sheet can distance between two bulkheads isnt very long An advantage 1A6 sheet material sand necessary will hold contour better Blot excess water 146 sheet wrap over foam mold will notice isnt going conform persuasion use masking tape start wrapping balsa tightly over center StyrofoamTM work toward end closer wrap toward end the balsa will want gather middle does can no longer wrap tape form cut down middie extra balsa razor blade Now have two folds take lap over other lay flat may have make center cut tad longer Wrap piece tape over overlapping balsa cut down center wood straightedge razor blade Remove tape excess balsa Wrap remainder sheeting end mold repeat process other end Put aside dry thoroughly After balsa dry remember takes longer underneath tape carefully remove tape form balsa should pop away mold should have part looks almost though vacuum-formed Carefully glue seams either end let dry place balsa sheeting back form sand bottom both ends conform mold Dont go too far before placing model final fit Looks pretty good eh would rather use 142 sheet have idea should help After sheeting has fitted fuselage ready gluing use StyrofoamTM mold slice February 1998 117 19-inch 68-ounce fuselage Folkerts SK3 showing StyrofoamTM mold used form piece balsa sheeting one-piece sheeting compound curves floor mold 1/i6 sheet balsa Stanleys circle cutters Cutting blade left cutting out Making other cut tire part-way through have center disk right outer ring whole balsa sheet hold onto instead small ring some bulkheads out glue onto inside form procedure doesnt take too much time results gratifying can pass idea aid keeping balsa form distorting after doping got idea 30 years ago model tried still looks good first day theres no sagging distortion mixed clear Hobbypoxy heated light source use open flame heat light causes material become watery thin its brushed onto underside sheeting coat amount weight gain negligible worth mentioning locks balsa distortion will occur find rocker-arm covers pain make especially same shape size round cowls did left off cowl wouldnt look right simple solution piece shim brass carefully cut correct shape rocker arm viewed top plan view file eliminate burrs brass should thick enough will bend easily using sanding platform Solder piece brass tubing 5A2 diameter right angles brass shape Cut balsa correct length height pieces will become rocker anus Place drop thick CyA cyanoacrylate glue brass attach balsa pieces Sand around edge get proper plan-view shape sand correct profile shape round out overall shape Carefully remove balsa razorblade scrape excess CyA brass form repeat next step may necessary depends overall radius cowl have Since rocker-arm covers have flat bottoms may want radius fit flat cowl easiest way tape small piece sandpaper onto cowl carefully sand sideways have seen bump cowls rockerarm covers made part cowl done making overall cowl several sections section would least three rocker-arm covers made hand-forming female mold hydraulically forming using dies Another way make rocker-arm separately rivet cowl mention because after glue rocker-arm covers onto cowl small amount balsa filler should used around want create look too formed butt-jointed Several years ago needed make pair simulated wire wheels diesel-powered Austin Whippet biplane commercially available wheels correct size got idea making some easy way Stanley tool company makes circlecutting tool ideal carving balsa plywood dynamite cutting out parts round cowls Notice blades pointing photosone cuts outside circle other cuts inside allowing actually cut tires balsa sheet drill press care required because tool spinning around can very dangerous Cut plywood disk diameter size required model plywoods thickness can /i6 3A2 depending models size cut couple balsa rings wheel Cut outside diameter first making certain cut way through sheet balsa safety reasons leaves sheet hold just small disk change cutters can cut center ring using hole made first cut align second time cut way through sheet use X ActorM cut outer side ring sheet other rings done same way Get scrap piece wood just large enough construct wheel drill hole axle made aluminum tubing case OD hole made drill press tube has vertical length tubing inserted hole length critical because trimmed later Most wheels vintage flat back side triangulated front counted 16 simulated spokes Williams Bros WW wheel requires spoke 2250 apart cut 16 triangles appropriate height length 1/64 plywood epoxied onto axle plywood disk assembly dry covered back front wheel lightweight fabricSolartex caseand sprayed silver two rings glued either side wheel after painted Floquils Grimy Black little contouring tire sandpaper followed paint touch-up finished decentlooking wheel too much effort Can make water-type decals using computer would certaialy like know Any help would greatly appreciated because Folkerts model holding stage until find out tremendous amount artwork particular airplane would also appreciate would send photos latest Scale model creation can share others Model Aviation ure used holding aluminum tubing vertically position 1/81 plywood triangles epoxied place Above below views beautiful Rubber Scale model 1921 Mitsubishi iMFi built Tom Halman Macungie PA
Edition: Model Aviation - 1998/02
Page Numbers: 117, 118
FREE FLIGHT SPORT SCALE Im going discuss couple areas construction hope will find informative useful first involves sheeting fuselage represent metal full-size aircraft Often smaller Rubber scale model stringers used instead sheeting doesnt look nearly good other option seen frequently use stringers balsa sandwiched between uillow opinion least desirable smooth contour virtually impossible because of glue joints glue being harder balsa doesnt allow uniform sanding know some glues sand pretty well problem still exists can get sheeting looks good doesnt create weight penalty Folkerts SK3 shown weighs 191 grams 68 ounces fuselage length 19 inches Thats bad considering much better fuselage looks appropriate sheeting top bottom sheeting have compound curves both made sheet balsa Read see its done Another photo shows piece StyrofoamTM has contoured fit between two bulkheads firewall cockpit will become mold sorts make use piece 1/16 balsa sheet will become floor mold sheet will have shape fuselage viewed top Balsa bulkheads cut proper shape dictated plan glued end sheet StyrofoamTM cut fit between floor two bulkheads assembly glued place StyrofoamTM sanded proper contour Choose lightest piece 1/16 balsa sheet large enough wrap over foam soak water several hours important because want wood supple possible may wonder use 1/i2 sheet can distance between two bulkheads isnt very long An advantage 1A6 sheet material sand necessary will hold contour better Blot excess water 146 sheet wrap over foam mold will notice isnt going conform persuasion use masking tape start wrapping balsa tightly over center StyrofoamTM work toward end closer wrap toward end the balsa will want gather middle does can no longer wrap tape form cut down middie extra balsa razor blade Now have two folds take lap over other lay flat may have make center cut tad longer Wrap piece tape over overlapping balsa cut down center wood straightedge razor blade Remove tape excess balsa Wrap remainder sheeting end mold repeat process other end Put aside dry thoroughly After balsa dry remember takes longer underneath tape carefully remove tape form balsa should pop away mold should have part looks almost though vacuum-formed Carefully glue seams either end let dry place balsa sheeting back form sand bottom both ends conform mold Dont go too far before placing model final fit Looks pretty good eh would rather use 142 sheet have idea should help After sheeting has fitted fuselage ready gluing use StyrofoamTM mold slice February 1998 117 19-inch 68-ounce fuselage Folkerts SK3 showing StyrofoamTM mold used form piece balsa sheeting one-piece sheeting compound curves floor mold 1/i6 sheet balsa Stanleys circle cutters Cutting blade left cutting out Making other cut tire part-way through have center disk right outer ring whole balsa sheet hold onto instead small ring some bulkheads out glue onto inside form procedure doesnt take too much time results gratifying can pass idea aid keeping balsa form distorting after doping got idea 30 years ago model tried still looks good first day theres no sagging distortion mixed clear Hobbypoxy heated light source use open flame heat light causes material become watery thin its brushed onto underside sheeting coat amount weight gain negligible worth mentioning locks balsa distortion will occur find rocker-arm covers pain make especially same shape size round cowls did left off cowl wouldnt look right simple solution piece shim brass carefully cut correct shape rocker arm viewed top plan view file eliminate burrs brass should thick enough will bend easily using sanding platform Solder piece brass tubing 5A2 diameter right angles brass shape Cut balsa correct length height pieces will become rocker anus Place drop thick CyA cyanoacrylate glue brass attach balsa pieces Sand around edge get proper plan-view shape sand correct profile shape round out overall shape Carefully remove balsa razorblade scrape excess CyA brass form repeat next step may necessary depends overall radius cowl have Since rocker-arm covers have flat bottoms may want radius fit flat cowl easiest way tape small piece sandpaper onto cowl carefully sand sideways have seen bump cowls rockerarm covers made part cowl done making overall cowl several sections section would least three rocker-arm covers made hand-forming female mold hydraulically forming using dies Another way make rocker-arm separately rivet cowl mention because after glue rocker-arm covers onto cowl small amount balsa filler should used around want create look too formed butt-jointed Several years ago needed make pair simulated wire wheels diesel-powered Austin Whippet biplane commercially available wheels correct size got idea making some easy way Stanley tool company makes circlecutting tool ideal carving balsa plywood dynamite cutting out parts round cowls Notice blades pointing photosone cuts outside circle other cuts inside allowing actually cut tires balsa sheet drill press care required because tool spinning around can very dangerous Cut plywood disk diameter size required model plywoods thickness can /i6 3A2 depending models size cut couple balsa rings wheel Cut outside diameter first making certain cut way through sheet balsa safety reasons leaves sheet hold just small disk change cutters can cut center ring using hole made first cut align second time cut way through sheet use X ActorM cut outer side ring sheet other rings done same way Get scrap piece wood just large enough construct wheel drill hole axle made aluminum tubing case OD hole made drill press tube has vertical length tubing inserted hole length critical because trimmed later Most wheels vintage flat back side triangulated front counted 16 simulated spokes Williams Bros WW wheel requires spoke 2250 apart cut 16 triangles appropriate height length 1/64 plywood epoxied onto axle plywood disk assembly dry covered back front wheel lightweight fabricSolartex caseand sprayed silver two rings glued either side wheel after painted Floquils Grimy Black little contouring tire sandpaper followed paint touch-up finished decentlooking wheel too much effort Can make water-type decals using computer would certaialy like know Any help would greatly appreciated because Folkerts model holding stage until find out tremendous amount artwork particular airplane would also appreciate would send photos latest Scale model creation can share others Model Aviation ure used holding aluminum tubing vertically position 1/81 plywood triangles epoxied place Above below views beautiful Rubber Scale model 1921 Mitsubishi iMFi built Tom Halman Macungie PA