Model tne 19 Tooth would have much leverage cause warps small patches created same reason important cement Mylar applied fuselage stabilizer structural members comes contact formers diagonals ribs sparsrather just around edges torsional forces fuselage stab great enough warrant use silkspan its increased weight hazards building light possibility going too far building too weak lighter plane faster will climb under power Since lift drag proportional square velocity stress directly proportional lift drag stresses will increase square velocity Simply lighter plane stronger needs rewards successfully building light substantial example 20-ox plane accelerates upwards 50% faster same plane weighing 26 oz based 60-ox thrust mention slower rate glide descent recognize critical flight stresses wing vulnerable because planes lift drag forces acting Flexural torsional flutter singly com bination fixed divergence can occur flexural motion change dihedral resisted wing spars whereas torsional motion twisting action resisted geodetic ribs covering material trailing half airfoil inherently weaker leading half because thinner Therefore neutral bending axis generally parallel chord line downwardly inclined front somewhat wing flexes toward dihedral tends toward washout bends neutral axis will cause diving tendancy high speed wing flexes some degree stabilizer also flexes like amount effects neutralizes other constant angular difference maintained Therefore wing stab should have approximately match ing stresses Since forces stabilizer relatively low stab lift drag per square inch area less half wing stab construc tion should made very light compared wing light stab helps other ways too permits short nose moment engine pulled up under leading edge wing good stability under power Also light stab tail end general reduces planes moment inertia improve glide through responsive maintenance constant angle attack choppy air Construction wing built two halves top piece box spar turbulator spars left off inboard panels Also leave out five center ribs Note two halves joined two diamond-shaped 1/64 plywood pieces top other bottom Epoxy two halves together proper angle lower 1/64 plywood piece place After has set add five center ribs -in center webs upper 1/64 plywood piece Finally add top pieces box spar side webs complete box Cover wing medium-weight silkspan three coats dope best build washin washout like doesnt get done confess rig wing bent paper clips string tied workshop ceiling twist wing weights doping silkspan After dope has cured criss-cross top bottom wing -in Mylar tape following pattem geodetic ribs Now cover wing -mil Mylar Stick wing outline criss-crossed tape use Quik Stik brand contact cement made Coverite purpose sure overlap Mylar onto itself -in seams Put about dozen pin pricks top bottom wing relieve hot air shrinking Mylar Ive best results doing shrinking job steps using heat-sealing iron90% first day balance over two-week period Set warps go shrink Mylar Periodically thereafter check warps pull back should drift wing will take permanent set ages Spray front one-third top wing stab very very lightly fast-drying enamel give some turbulation roughness Mylar Spray several feet away spray particles partially dry before landing will give somewhat rough finish light slow-gliding plane top boundary layer may need energized bitas provided paint texture 60 Model Aviation Author peaks out engine prior launch Note tweaking being done climbing atti tude maximum rigidity wing covered silkspan A-mu Mylar TWO A-H-U Tootflplckstfle authorat Iett son jim right ne autnortooKTIrst iass U upen gg Nats first Class Open i980 Nats Article has valuable tips D4ASIEU1 ~ %OFHA CAP OF H IP NT H H EL B SO D-D II 2 SAWH nH /9 \ j C C-c CHABBOL LEFT FULL LINE PIHCEE1 FOAM ______________________________________WINE BLOB L7 I--— 3 LEFTIIi~TAN NSF TOPUHOT 1% BEWOLATTACH PUILA INST BR EL LABIABIABAHOLE OPPOELEL OH FLHElSE IO CHOSE CALEB E,5 SHEET THEL hAL P11CC HOETHACROSS CHAIN 2 4 UL EACH OF 34 AS4E P/FWE ALTALLS BELAW A/HEHPLLTLBBL I/0E0EPHOCEI------IPTfI7r EWEfl---ETF2F3IIF4--I%SEBIECLET HEFIECTER TNI.BIIII STLCH AB THET LIWEpS~jAj~EEC ALBA /L4 PLY BOLl 3/ 5~~iJR1Xr1EE0 LHINTBNCA PEECESTHALOB FOCI LIAL~2WASHFHBATLILH.ALEILL ABBAT2 PU BA FL AL BA L4 PITBA4 PIToELTHAC HEAL WALL EN 3WLSH OOT~H TOICO ELLABLABLO O-T ETNIAC STOPCOT B BLAB1BLLAT LAB EJAUI BBBHN TTINEB B C F FS-FFTF2 ____ df~F3F4Fl IT 0/OL SLEETS4 SB0 0/4WILE LOEBO LOAP TEN BT TEENEN ETNEAL DAMART FOCAl TIHEB-OT TIMELHNCBOP TOLL EChO LOFT BALSA FHCM LIHEANIL TB TLIS PHI NT POACH BOB TBABA EISLEEFBE EENEAOSEE HEAL BACH ELIOT SO EN ETCH AREA TEL LB IA HEAL NENFOEI BS SIAPIEB ILBEARITAMIC SPEALL LENA AENLBIETI REbUT FOSELOCESC EC/ALH IA HI CT HEAL TCH TOTAl L/OIL ELI NOTE NE HISHE NCBE BELA MN LEO TI RH TOP SPAB FOECLALEL STABLILUT COATTET CROAB BOLLO CEBERILLHIHLMLBIOM WI LELALPON WITH TANEE ECOTE LT HOPE F/C OIL AFLAL OHENALL ETANE NIL MYLAR FLSLLOE EAPAHESE TISSUE COLA WHOA PART MEL HYENA ACT OPEN WOBA HAL A13C TOOTHPICKS BY GAL ELNORRES 070 MELEE WIRE LANBIMO BEAN FOB BEN IASF 9F 2345678 / /7/ 4A BIGHT BEEBE PIT ALLOT Bj SB ALL RB 1 C m z C, w m C, m m m 0 0 Build bottom fuselage surface first pinned directly plans add formers Off side cut top two longerons taper ends join rear cement together Place sub-assembly onto formers pulling longerons conform same contour bottom cement top corners formers diagonals can put last after assembly removed board Use epoxy slow curing kind cement wing center section together fasten firewall 1/64 plywood shield around 1/16 plywood stab rest l back stab other cement work done model airplane glue dont key wing stab alignment preferring eyeball before flight K&B 325 35 use 8 x 4 Zinger old style Master Screw prop 60% nitro fueL Flying Note trim adjustments shown plans plane should go almost straight up gentle twist right transition top gradual left glide turn should transition perfectly 3-sec engine run Best results delaying auto-stab lift two seconds after engine cutoff airplane important engine flying style An engine starts easily within couple flips advantage Invariably stubborn engine will upset timing cause delay launch will put down air back side thermal Odds against maxing between hours 10 12 am have stung too may downers during hours coinci dental theorize normal day thermal activity progresses something like following During night temperatures equalize early morning hours no temperature differences produce vertical air movement air cool dense favorable maxing thermal assistance Get first flight early possible However sun heats earths surface temperature differences generated starting thermal activity time should have maxed out ready flyoffs patient Open fields highways runways readily absorb suns rays Areas foliage such woods cornfields soy bean fields heavy grass-covered fields effectively insulated suns raysthere fore absorb heat slowly open fieldssuch likely flying What means surfaces open fields remain cool suns heat easily absorbed mass earth top surfaces foliage foliage-covered areas heat up quickly because heat readily conducted away Standing thermals form over foliage-cov ered areas standing downers prevail over open fields condition per sists roughly between 10 12 oclock isnt say no thermals over flying field 10 12 Thermal bubbles neighboring fields will blown over during time superimposed will standing downer makes air picking particularly tricky sta tistically unfavorable suppose enterprising could win consistently flying over cornfields woods during hours Finally surface open fields heat up earths crust has heated Its temperature approaches surfaces surround ing foliage-covered areas time say between 12 2 different picture develops Dark rough areas such macadam freshly plowed fields still absorb heatwhile lighter areas such concrete runways light tan hard dirt fields up temperature now heating surface air producing thermals Barring other weather factors now time flyoffs starting about 1 oclock about 2 &clock later process much reverse what 10 12 surfaces black-top areas have become hotter anything around foliage areas still fully up temperature suns heat being slowly drawn away still-cool earth undemeath Therefore afternoon flying field tends produce standing thermals surrounding areas tend produce stand ing downers condition becomes particularly apparent late afternoon eveningup perhaps midnightwhen hot fields give up stored heat cooling air foliage-covered areas have less stored heat return atmosphere discussion somewhat idealized because ignores larger air movements fronts cloud coverage etc contest day dawns clear forecast fair calm day watch conditions occur forecast otherwise static conditions will develop less apparent other dynamic weather factors superimposed confuse Continued page 132 62 Model Aviation uuun aneaa inc riooa-orr rimer pincnes ruci iine opposite side pusneananoy ror quick starts Landing gear captured between engine backplateand through beam mounting holes Upper rubberband released engine timer holds string going stab dowel Lower rubberband holds dethermalizer timer switch position Bottom string holding stab dowel released engine timer allow stab lift glide position Top string holding auto-stab arm later released bythedethermalizertimerto allow stabilizer swing up dethermalized position Stab covered 1/2-mil Mylar 3 ounces fuel rarely needs plug runs kind fuel Ive tried sorts synthetics castor nitro percentages 5-60% engine seems prefer around 20% oil 15% Klotz 5% castor goes faster addition nitro case some engines nitro means sensitive needle settings blown plugs some times less power until head clearance/shape changed Maximum power motor limited because still has rather small stock venturi Just what always wanted Monoboom SP SP stands Speed Pattern event might catch some day Its tried various parts country already fixed series loops eights level flight total elapsed time what counts think trying AMA Stunt Pattern about two half minutes SP plane will larger set up rear exhaust engines like K&B Tigre 40 straight pipe talking lots horsepower like 130mph-producing horsepower Proponents say event future non-destructive measure pilot skill model/engine perfor mance Whatever happened lady luck come FAI Combat Team Trials arent Nationals like other CL events guess main reason amd tell people Combat program well organized locked before Nats location became real possibility Stunt/Team Race Speed nothing firmed up able change Nationals location time Editors note Since written Stunt finals have also moved Natsto Dayton OH Labor Day weekend Lets hope planning great facilities Nashville make up extra travel expense bonus having Combat portion separate added publicity Combat will receive Charlie Johnson 3716 Ingraham St San Diego CA 92109 A-B-C Toothpicks/Morris Continued page 62 picture Speaking weather forecasts certain old almanac folklore sayings general ly true helpful some like Red night sailors delight Red morning sailors take waming Rain before 7 ends before 11 smoke descends good weather ends Sharp horns meaning unusually clear points partial moon threaten high winds Rain long foretold long last short notice soon past Fair weather guides Rising smoke indicates high barometric pressurethus clear day Dew sign fair day No matter ominous appear high clouds wont rain Foul weather guides Sun moon halos indi cate coming rain leaves turn over show backs rain its way storm clouds appear west northwest usually indicates storm will reach Storms south go past Put together plane engine flying styleand bound tough competi tor However slow process Allow year bring new plane up full potential Happy landings FF Scale/Warner Continued page 63 model flew 1981 Astro-Flight Model Builder Champs has 3/16-in aluminum tubing drive shaft going back prop motor cockpit area Bits thin Teflon sheet surplus store punched out tubing OD bracketed Ambroid giue places tubing passed through bulkheads its way rearward took vibration out shaft very nicely Glue wont stick Teflon will hold place smeared around over edges squares cut just little larger 3/16 hole center probably could have eliminated break bronze bearing half way back shaft used attempt steady didnt job eliminating vibrationbut Teflon did few planes props halfway back fuselage such Joe Tschirgis famous DuFaux amaze people cant see whole rear plane doesnt revolve too Vancouver BC correspondent artist Dick Allen gives away secret electricmotor-driven conception its done Quite simply long stationary shaft ties front back fuselage together prop shaft really free-spinning tube fits over non-moving structural member spun belt gears great job electric thinking shaft-drive plane just remember keep light can try support drive shaft intervals keep shake out try keep shaft motor line Minor bends drive line can accomplished using Hungerford method wound music wire spring point direction-change provide needed flexibility Having used PATTERN AND 004 HIGH SPEED PROPELLERS AIRSCREW CUSTOM HIGH PERFORMANCE MAPLE PROPELLERS Propeller designed usin2 symmetrical profile Individually precision hand balanced Accurale airfoil pitch Only high quality straight grain Eastern Maple used a% x 6% FORMULA 1 iox S lix 11X712 iixs CUSTOM DESIGN UPON REQUE ST OrRECT SALES mv 5634 CRYSTAL COAST SANTA ROSA CA SSAAA PRONE 707 SOSSODA Add RIDS pe dR POStage handling CA DES ADO 5% TAA TLC R/C PRODUCTS Rt 1 Box 282 Prospect VA 23901 Solareraft presents 2 new fun flyers Betas DesS 12 rubber powered helicopter climbs over 250 $300 postage paid ready fly Belar Scamp 12 high performance free flying stick model $400 postage paid ready fly Send check orde Solarcraft F)Boxhh2isanta1arhara CA92111 llsalsr Inquirle invitetl 132 Model Aviation 6$ 4 Fast realistic aerobatic kit features ABS wheelpants moUlded canopy pre-bent wire Send $2500 plus $500 shipping to
Edition: Model Aviation - 1981/07
Page Numbers: 59, 60, 61, 62, 132
Model tne 19 Tooth would have much leverage cause warps small patches created same reason important cement Mylar applied fuselage stabilizer structural members comes contact formers diagonals ribs sparsrather just around edges torsional forces fuselage stab great enough warrant use silkspan its increased weight hazards building light possibility going too far building too weak lighter plane faster will climb under power Since lift drag proportional square velocity stress directly proportional lift drag stresses will increase square velocity Simply lighter plane stronger needs rewards successfully building light substantial example 20-ox plane accelerates upwards 50% faster same plane weighing 26 oz based 60-ox thrust mention slower rate glide descent recognize critical flight stresses wing vulnerable because planes lift drag forces acting Flexural torsional flutter singly com bination fixed divergence can occur flexural motion change dihedral resisted wing spars whereas torsional motion twisting action resisted geodetic ribs covering material trailing half airfoil inherently weaker leading half because thinner Therefore neutral bending axis generally parallel chord line downwardly inclined front somewhat wing flexes toward dihedral tends toward washout bends neutral axis will cause diving tendancy high speed wing flexes some degree stabilizer also flexes like amount effects neutralizes other constant angular difference maintained Therefore wing stab should have approximately match ing stresses Since forces stabilizer relatively low stab lift drag per square inch area less half wing stab construc tion should made very light compared wing light stab helps other ways too permits short nose moment engine pulled up under leading edge wing good stability under power Also light stab tail end general reduces planes moment inertia improve glide through responsive maintenance constant angle attack choppy air Construction wing built two halves top piece box spar turbulator spars left off inboard panels Also leave out five center ribs Note two halves joined two diamond-shaped 1/64 plywood pieces top other bottom Epoxy two halves together proper angle lower 1/64 plywood piece place After has set add five center ribs -in center webs upper 1/64 plywood piece Finally add top pieces box spar side webs complete box Cover wing medium-weight silkspan three coats dope best build washin washout like doesnt get done confess rig wing bent paper clips string tied workshop ceiling twist wing weights doping silkspan After dope has cured criss-cross top bottom wing -in Mylar tape following pattem geodetic ribs Now cover wing -mil Mylar Stick wing outline criss-crossed tape use Quik Stik brand contact cement made Coverite purpose sure overlap Mylar onto itself -in seams Put about dozen pin pricks top bottom wing relieve hot air shrinking Mylar Ive best results doing shrinking job steps using heat-sealing iron90% first day balance over two-week period Set warps go shrink Mylar Periodically thereafter check warps pull back should drift wing will take permanent set ages Spray front one-third top wing stab very very lightly fast-drying enamel give some turbulation roughness Mylar Spray several feet away spray particles partially dry before landing will give somewhat rough finish light slow-gliding plane top boundary layer may need energized bitas provided paint texture 60 Model Aviation Author peaks out engine prior launch Note tweaking being done climbing atti tude maximum rigidity wing covered silkspan A-mu Mylar TWO A-H-U Tootflplckstfle authorat Iett son jim right ne autnortooKTIrst iass U upen gg Nats first Class Open i980 Nats Article has valuable tips D4ASIEU1 ~ %OFHA CAP OF H IP NT H H EL B SO D-D II 2 SAWH nH /9 \ j C C-c CHABBOL LEFT FULL LINE PIHCEE1 FOAM ______________________________________WINE BLOB L7 I--— 3 LEFTIIi~TAN NSF TOPUHOT 1% BEWOLATTACH PUILA INST BR EL LABIABIABAHOLE OPPOELEL OH FLHElSE IO CHOSE CALEB E,5 SHEET THEL hAL P11CC HOETHACROSS CHAIN 2 4 UL EACH OF 34 AS4E P/FWE ALTALLS BELAW A/HEHPLLTLBBL I/0E0EPHOCEI------IPTfI7r EWEfl---ETF2F3IIF4--I%SEBIECLET HEFIECTER TNI.BIIII STLCH AB THET LIWEpS~jAj~EEC ALBA /L4 PLY BOLl 3/ 5~~iJR1Xr1EE0 LHINTBNCA PEECESTHALOB FOCI LIAL~2WASHFHBATLILH.ALEILL ABBAT2 PU BA FL AL BA L4 PITBA4 PIToELTHAC HEAL WALL EN 3WLSH OOT~H TOICO ELLABLABLO O-T ETNIAC STOPCOT B BLAB1BLLAT LAB EJAUI BBBHN TTINEB B C F FS-FFTF2 ____ df~F3F4Fl IT 0/OL SLEETS4 SB0 0/4WILE LOEBO LOAP TEN BT TEENEN ETNEAL DAMART FOCAl TIHEB-OT TIMELHNCBOP TOLL EChO LOFT BALSA FHCM LIHEANIL TB TLIS PHI NT POACH BOB TBABA EISLEEFBE EENEAOSEE HEAL BACH ELIOT SO EN ETCH AREA TEL LB IA HEAL NENFOEI BS SIAPIEB ILBEARITAMIC SPEALL LENA AENLBIETI REbUT FOSELOCESC EC/ALH IA HI CT HEAL TCH TOTAl L/OIL ELI NOTE NE HISHE NCBE BELA MN LEO TI RH TOP SPAB FOECLALEL STABLILUT COATTET CROAB BOLLO CEBERILLHIHLMLBIOM WI LELALPON WITH TANEE ECOTE LT HOPE F/C OIL AFLAL OHENALL ETANE NIL MYLAR FLSLLOE EAPAHESE TISSUE COLA WHOA PART MEL HYENA ACT OPEN WOBA HAL A13C TOOTHPICKS BY GAL ELNORRES 070 MELEE WIRE LANBIMO BEAN FOB BEN IASF 9F 2345678 / /7/ 4A BIGHT BEEBE PIT ALLOT Bj SB ALL RB 1 C m z C, w m C, m m m 0 0 Build bottom fuselage surface first pinned directly plans add formers Off side cut top two longerons taper ends join rear cement together Place sub-assembly onto formers pulling longerons conform same contour bottom cement top corners formers diagonals can put last after assembly removed board Use epoxy slow curing kind cement wing center section together fasten firewall 1/64 plywood shield around 1/16 plywood stab rest l back stab other cement work done model airplane glue dont key wing stab alignment preferring eyeball before flight K&B 325 35 use 8 x 4 Zinger old style Master Screw prop 60% nitro fueL Flying Note trim adjustments shown plans plane should go almost straight up gentle twist right transition top gradual left glide turn should transition perfectly 3-sec engine run Best results delaying auto-stab lift two seconds after engine cutoff airplane important engine flying style An engine starts easily within couple flips advantage Invariably stubborn engine will upset timing cause delay launch will put down air back side thermal Odds against maxing between hours 10 12 am have stung too may downers during hours coinci dental theorize normal day thermal activity progresses something like following During night temperatures equalize early morning hours no temperature differences produce vertical air movement air cool dense favorable maxing thermal assistance Get first flight early possible However sun heats earths surface temperature differences generated starting thermal activity time should have maxed out ready flyoffs patient Open fields highways runways readily absorb suns rays Areas foliage such woods cornfields soy bean fields heavy grass-covered fields effectively insulated suns raysthere fore absorb heat slowly open fieldssuch likely flying What means surfaces open fields remain cool suns heat easily absorbed mass earth top surfaces foliage foliage-covered areas heat up quickly because heat readily conducted away Standing thermals form over foliage-cov ered areas standing downers prevail over open fields condition per sists roughly between 10 12 oclock isnt say no thermals over flying field 10 12 Thermal bubbles neighboring fields will blown over during time superimposed will standing downer makes air picking particularly tricky sta tistically unfavorable suppose enterprising could win consistently flying over cornfields woods during hours Finally surface open fields heat up earths crust has heated Its temperature approaches surfaces surround ing foliage-covered areas time say between 12 2 different picture develops Dark rough areas such macadam freshly plowed fields still absorb heatwhile lighter areas such concrete runways light tan hard dirt fields up temperature now heating surface air producing thermals Barring other weather factors now time flyoffs starting about 1 oclock about 2 &clock later process much reverse what 10 12 surfaces black-top areas have become hotter anything around foliage areas still fully up temperature suns heat being slowly drawn away still-cool earth undemeath Therefore afternoon flying field tends produce standing thermals surrounding areas tend produce stand ing downers condition becomes particularly apparent late afternoon eveningup perhaps midnightwhen hot fields give up stored heat cooling air foliage-covered areas have less stored heat return atmosphere discussion somewhat idealized because ignores larger air movements fronts cloud coverage etc contest day dawns clear forecast fair calm day watch conditions occur forecast otherwise static conditions will develop less apparent other dynamic weather factors superimposed confuse Continued page 132 62 Model Aviation uuun aneaa inc riooa-orr rimer pincnes ruci iine opposite side pusneananoy ror quick starts Landing gear captured between engine backplateand through beam mounting holes Upper rubberband released engine timer holds string going stab dowel Lower rubberband holds dethermalizer timer switch position Bottom string holding stab dowel released engine timer allow stab lift glide position Top string holding auto-stab arm later released bythedethermalizertimerto allow stabilizer swing up dethermalized position Stab covered 1/2-mil Mylar 3 ounces fuel rarely needs plug runs kind fuel Ive tried sorts synthetics castor nitro percentages 5-60% engine seems prefer around 20% oil 15% Klotz 5% castor goes faster addition nitro case some engines nitro means sensitive needle settings blown plugs some times less power until head clearance/shape changed Maximum power motor limited because still has rather small stock venturi Just what always wanted Monoboom SP SP stands Speed Pattern event might catch some day Its tried various parts country already fixed series loops eights level flight total elapsed time what counts think trying AMA Stunt Pattern about two half minutes SP plane will larger set up rear exhaust engines like K&B Tigre 40 straight pipe talking lots horsepower like 130mph-producing horsepower Proponents say event future non-destructive measure pilot skill model/engine perfor mance Whatever happened lady luck come FAI Combat Team Trials arent Nationals like other CL events guess main reason amd tell people Combat program well organized locked before Nats location became real possibility Stunt/Team Race Speed nothing firmed up able change Nationals location time Editors note Since written Stunt finals have also moved Natsto Dayton OH Labor Day weekend Lets hope planning great facilities Nashville make up extra travel expense bonus having Combat portion separate added publicity Combat will receive Charlie Johnson 3716 Ingraham St San Diego CA 92109 A-B-C Toothpicks/Morris Continued page 62 picture Speaking weather forecasts certain old almanac folklore sayings general ly true helpful some like Red night sailors delight Red morning sailors take waming Rain before 7 ends before 11 smoke descends good weather ends Sharp horns meaning unusually clear points partial moon threaten high winds Rain long foretold long last short notice soon past Fair weather guides Rising smoke indicates high barometric pressurethus clear day Dew sign fair day No matter ominous appear high clouds wont rain Foul weather guides Sun moon halos indi cate coming rain leaves turn over show backs rain its way storm clouds appear west northwest usually indicates storm will reach Storms south go past Put together plane engine flying styleand bound tough competi tor However slow process Allow year bring new plane up full potential Happy landings FF Scale/Warner Continued page 63 model flew 1981 Astro-Flight Model Builder Champs has 3/16-in aluminum tubing drive shaft going back prop motor cockpit area Bits thin Teflon sheet surplus store punched out tubing OD bracketed Ambroid giue places tubing passed through bulkheads its way rearward took vibration out shaft very nicely Glue wont stick Teflon will hold place smeared around over edges squares cut just little larger 3/16 hole center probably could have eliminated break bronze bearing half way back shaft used attempt steady didnt job eliminating vibrationbut Teflon did few planes props halfway back fuselage such Joe Tschirgis famous DuFaux amaze people cant see whole rear plane doesnt revolve too Vancouver BC correspondent artist Dick Allen gives away secret electricmotor-driven conception its done Quite simply long stationary shaft ties front back fuselage together prop shaft really free-spinning tube fits over non-moving structural member spun belt gears great job electric thinking shaft-drive plane just remember keep light can try support drive shaft intervals keep shake out try keep shaft motor line Minor bends drive line can accomplished using Hungerford method wound music wire spring point direction-change provide needed flexibility Having used PATTERN AND 004 HIGH SPEED PROPELLERS AIRSCREW CUSTOM HIGH PERFORMANCE MAPLE PROPELLERS Propeller designed usin2 symmetrical profile Individually precision hand balanced Accurale airfoil pitch Only high quality straight grain Eastern Maple used a% x 6% FORMULA 1 iox S lix 11X712 iixs CUSTOM DESIGN UPON REQUE ST OrRECT SALES mv 5634 CRYSTAL COAST SANTA ROSA CA SSAAA PRONE 707 SOSSODA Add RIDS pe dR POStage handling CA DES ADO 5% TAA TLC R/C PRODUCTS Rt 1 Box 282 Prospect VA 23901 Solareraft presents 2 new fun flyers Betas DesS 12 rubber powered helicopter climbs over 250 $300 postage paid ready fly Belar Scamp 12 high performance free flying stick model $400 postage paid ready fly Send check orde Solarcraft F)Boxhh2isanta1arhara CA92111 llsalsr Inquirle invitetl 132 Model Aviation 6$ 4 Fast realistic aerobatic kit features ABS wheelpants moUlded canopy pre-bent wire Send $2500 plus $500 shipping to
Edition: Model Aviation - 1981/07
Page Numbers: 59, 60, 61, 62, 132
Model tne 19 Tooth would have much leverage cause warps small patches created same reason important cement Mylar applied fuselage stabilizer structural members comes contact formers diagonals ribs sparsrather just around edges torsional forces fuselage stab great enough warrant use silkspan its increased weight hazards building light possibility going too far building too weak lighter plane faster will climb under power Since lift drag proportional square velocity stress directly proportional lift drag stresses will increase square velocity Simply lighter plane stronger needs rewards successfully building light substantial example 20-ox plane accelerates upwards 50% faster same plane weighing 26 oz based 60-ox thrust mention slower rate glide descent recognize critical flight stresses wing vulnerable because planes lift drag forces acting Flexural torsional flutter singly com bination fixed divergence can occur flexural motion change dihedral resisted wing spars whereas torsional motion twisting action resisted geodetic ribs covering material trailing half airfoil inherently weaker leading half because thinner Therefore neutral bending axis generally parallel chord line downwardly inclined front somewhat wing flexes toward dihedral tends toward washout bends neutral axis will cause diving tendancy high speed wing flexes some degree stabilizer also flexes like amount effects neutralizes other constant angular difference maintained Therefore wing stab should have approximately match ing stresses Since forces stabilizer relatively low stab lift drag per square inch area less half wing stab construc tion should made very light compared wing light stab helps other ways too permits short nose moment engine pulled up under leading edge wing good stability under power Also light stab tail end general reduces planes moment inertia improve glide through responsive maintenance constant angle attack choppy air Construction wing built two halves top piece box spar turbulator spars left off inboard panels Also leave out five center ribs Note two halves joined two diamond-shaped 1/64 plywood pieces top other bottom Epoxy two halves together proper angle lower 1/64 plywood piece place After has set add five center ribs -in center webs upper 1/64 plywood piece Finally add top pieces box spar side webs complete box Cover wing medium-weight silkspan three coats dope best build washin washout like doesnt get done confess rig wing bent paper clips string tied workshop ceiling twist wing weights doping silkspan After dope has cured criss-cross top bottom wing -in Mylar tape following pattem geodetic ribs Now cover wing -mil Mylar Stick wing outline criss-crossed tape use Quik Stik brand contact cement made Coverite purpose sure overlap Mylar onto itself -in seams Put about dozen pin pricks top bottom wing relieve hot air shrinking Mylar Ive best results doing shrinking job steps using heat-sealing iron90% first day balance over two-week period Set warps go shrink Mylar Periodically thereafter check warps pull back should drift wing will take permanent set ages Spray front one-third top wing stab very very lightly fast-drying enamel give some turbulation roughness Mylar Spray several feet away spray particles partially dry before landing will give somewhat rough finish light slow-gliding plane top boundary layer may need energized bitas provided paint texture 60 Model Aviation Author peaks out engine prior launch Note tweaking being done climbing atti tude maximum rigidity wing covered silkspan A-mu Mylar TWO A-H-U Tootflplckstfle authorat Iett son jim right ne autnortooKTIrst iass U upen gg Nats first Class Open i980 Nats Article has valuable tips D4ASIEU1 ~ %OFHA CAP OF H IP NT H H EL B SO D-D II 2 SAWH nH /9 \ j C C-c CHABBOL LEFT FULL LINE PIHCEE1 FOAM ______________________________________WINE BLOB L7 I--— 3 LEFTIIi~TAN NSF TOPUHOT 1% BEWOLATTACH PUILA INST BR EL LABIABIABAHOLE OPPOELEL OH FLHElSE IO CHOSE CALEB E,5 SHEET THEL hAL P11CC HOETHACROSS CHAIN 2 4 UL EACH OF 34 AS4E P/FWE ALTALLS BELAW A/HEHPLLTLBBL I/0E0EPHOCEI------IPTfI7r EWEfl---ETF2F3IIF4--I%SEBIECLET HEFIECTER TNI.BIIII STLCH AB THET LIWEpS~jAj~EEC ALBA /L4 PLY BOLl 3/ 5~~iJR1Xr1EE0 LHINTBNCA PEECESTHALOB FOCI LIAL~2WASHFHBATLILH.ALEILL ABBAT2 PU BA FL AL BA L4 PITBA4 PIToELTHAC HEAL WALL EN 3WLSH OOT~H TOICO ELLABLABLO O-T ETNIAC STOPCOT B BLAB1BLLAT LAB EJAUI BBBHN TTINEB B C F FS-FFTF2 ____ df~F3F4Fl IT 0/OL SLEETS4 SB0 0/4WILE LOEBO LOAP TEN BT TEENEN ETNEAL DAMART FOCAl TIHEB-OT TIMELHNCBOP TOLL EChO LOFT BALSA FHCM LIHEANIL TB TLIS PHI NT POACH BOB TBABA EISLEEFBE EENEAOSEE HEAL BACH ELIOT SO EN ETCH AREA TEL LB IA HEAL NENFOEI BS SIAPIEB ILBEARITAMIC SPEALL LENA AENLBIETI REbUT FOSELOCESC EC/ALH IA HI CT HEAL TCH TOTAl L/OIL ELI NOTE NE HISHE NCBE BELA MN LEO TI RH TOP SPAB FOECLALEL STABLILUT COATTET CROAB BOLLO CEBERILLHIHLMLBIOM WI LELALPON WITH TANEE ECOTE LT HOPE F/C OIL AFLAL OHENALL ETANE NIL MYLAR FLSLLOE EAPAHESE TISSUE COLA WHOA PART MEL HYENA ACT OPEN WOBA HAL A13C TOOTHPICKS BY GAL ELNORRES 070 MELEE WIRE LANBIMO BEAN FOB BEN IASF 9F 2345678 / /7/ 4A BIGHT BEEBE PIT ALLOT Bj SB ALL RB 1 C m z C, w m C, m m m 0 0 Build bottom fuselage surface first pinned directly plans add formers Off side cut top two longerons taper ends join rear cement together Place sub-assembly onto formers pulling longerons conform same contour bottom cement top corners formers diagonals can put last after assembly removed board Use epoxy slow curing kind cement wing center section together fasten firewall 1/64 plywood shield around 1/16 plywood stab rest l back stab other cement work done model airplane glue dont key wing stab alignment preferring eyeball before flight K&B 325 35 use 8 x 4 Zinger old style Master Screw prop 60% nitro fueL Flying Note trim adjustments shown plans plane should go almost straight up gentle twist right transition top gradual left glide turn should transition perfectly 3-sec engine run Best results delaying auto-stab lift two seconds after engine cutoff airplane important engine flying style An engine starts easily within couple flips advantage Invariably stubborn engine will upset timing cause delay launch will put down air back side thermal Odds against maxing between hours 10 12 am have stung too may downers during hours coinci dental theorize normal day thermal activity progresses something like following During night temperatures equalize early morning hours no temperature differences produce vertical air movement air cool dense favorable maxing thermal assistance Get first flight early possible However sun heats earths surface temperature differences generated starting thermal activity time should have maxed out ready flyoffs patient Open fields highways runways readily absorb suns rays Areas foliage such woods cornfields soy bean fields heavy grass-covered fields effectively insulated suns raysthere fore absorb heat slowly open fieldssuch likely flying What means surfaces open fields remain cool suns heat easily absorbed mass earth top surfaces foliage foliage-covered areas heat up quickly because heat readily conducted away Standing thermals form over foliage-cov ered areas standing downers prevail over open fields condition per sists roughly between 10 12 oclock isnt say no thermals over flying field 10 12 Thermal bubbles neighboring fields will blown over during time superimposed will standing downer makes air picking particularly tricky sta tistically unfavorable suppose enterprising could win consistently flying over cornfields woods during hours Finally surface open fields heat up earths crust has heated Its temperature approaches surfaces surround ing foliage-covered areas time say between 12 2 different picture develops Dark rough areas such macadam freshly plowed fields still absorb heatwhile lighter areas such concrete runways light tan hard dirt fields up temperature now heating surface air producing thermals Barring other weather factors now time flyoffs starting about 1 oclock about 2 &clock later process much reverse what 10 12 surfaces black-top areas have become hotter anything around foliage areas still fully up temperature suns heat being slowly drawn away still-cool earth undemeath Therefore afternoon flying field tends produce standing thermals surrounding areas tend produce stand ing downers condition becomes particularly apparent late afternoon eveningup perhaps midnightwhen hot fields give up stored heat cooling air foliage-covered areas have less stored heat return atmosphere discussion somewhat idealized because ignores larger air movements fronts cloud coverage etc contest day dawns clear forecast fair calm day watch conditions occur forecast otherwise static conditions will develop less apparent other dynamic weather factors superimposed confuse Continued page 132 62 Model Aviation uuun aneaa inc riooa-orr rimer pincnes ruci iine opposite side pusneananoy ror quick starts Landing gear captured between engine backplateand through beam mounting holes Upper rubberband released engine timer holds string going stab dowel Lower rubberband holds dethermalizer timer switch position Bottom string holding stab dowel released engine timer allow stab lift glide position Top string holding auto-stab arm later released bythedethermalizertimerto allow stabilizer swing up dethermalized position Stab covered 1/2-mil Mylar 3 ounces fuel rarely needs plug runs kind fuel Ive tried sorts synthetics castor nitro percentages 5-60% engine seems prefer around 20% oil 15% Klotz 5% castor goes faster addition nitro case some engines nitro means sensitive needle settings blown plugs some times less power until head clearance/shape changed Maximum power motor limited because still has rather small stock venturi Just what always wanted Monoboom SP SP stands Speed Pattern event might catch some day Its tried various parts country already fixed series loops eights level flight total elapsed time what counts think trying AMA Stunt Pattern about two half minutes SP plane will larger set up rear exhaust engines like K&B Tigre 40 straight pipe talking lots horsepower like 130mph-producing horsepower Proponents say event future non-destructive measure pilot skill model/engine perfor mance Whatever happened lady luck come FAI Combat Team Trials arent Nationals like other CL events guess main reason amd tell people Combat program well organized locked before Nats location became real possibility Stunt/Team Race Speed nothing firmed up able change Nationals location time Editors note Since written Stunt finals have also moved Natsto Dayton OH Labor Day weekend Lets hope planning great facilities Nashville make up extra travel expense bonus having Combat portion separate added publicity Combat will receive Charlie Johnson 3716 Ingraham St San Diego CA 92109 A-B-C Toothpicks/Morris Continued page 62 picture Speaking weather forecasts certain old almanac folklore sayings general ly true helpful some like Red night sailors delight Red morning sailors take waming Rain before 7 ends before 11 smoke descends good weather ends Sharp horns meaning unusually clear points partial moon threaten high winds Rain long foretold long last short notice soon past Fair weather guides Rising smoke indicates high barometric pressurethus clear day Dew sign fair day No matter ominous appear high clouds wont rain Foul weather guides Sun moon halos indi cate coming rain leaves turn over show backs rain its way storm clouds appear west northwest usually indicates storm will reach Storms south go past Put together plane engine flying styleand bound tough competi tor However slow process Allow year bring new plane up full potential Happy landings FF Scale/Warner Continued page 63 model flew 1981 Astro-Flight Model Builder Champs has 3/16-in aluminum tubing drive shaft going back prop motor cockpit area Bits thin Teflon sheet surplus store punched out tubing OD bracketed Ambroid giue places tubing passed through bulkheads its way rearward took vibration out shaft very nicely Glue wont stick Teflon will hold place smeared around over edges squares cut just little larger 3/16 hole center probably could have eliminated break bronze bearing half way back shaft used attempt steady didnt job eliminating vibrationbut Teflon did few planes props halfway back fuselage such Joe Tschirgis famous DuFaux amaze people cant see whole rear plane doesnt revolve too Vancouver BC correspondent artist Dick Allen gives away secret electricmotor-driven conception its done Quite simply long stationary shaft ties front back fuselage together prop shaft really free-spinning tube fits over non-moving structural member spun belt gears great job electric thinking shaft-drive plane just remember keep light can try support drive shaft intervals keep shake out try keep shaft motor line Minor bends drive line can accomplished using Hungerford method wound music wire spring point direction-change provide needed flexibility Having used PATTERN AND 004 HIGH SPEED PROPELLERS AIRSCREW CUSTOM HIGH PERFORMANCE MAPLE PROPELLERS Propeller designed usin2 symmetrical profile Individually precision hand balanced Accurale airfoil pitch Only high quality straight grain Eastern Maple used a% x 6% FORMULA 1 iox S lix 11X712 iixs CUSTOM DESIGN UPON REQUE ST OrRECT SALES mv 5634 CRYSTAL COAST SANTA ROSA CA SSAAA PRONE 707 SOSSODA Add RIDS pe dR POStage handling CA DES ADO 5% TAA TLC R/C PRODUCTS Rt 1 Box 282 Prospect VA 23901 Solareraft presents 2 new fun flyers Betas DesS 12 rubber powered helicopter climbs over 250 $300 postage paid ready fly Belar Scamp 12 high performance free flying stick model $400 postage paid ready fly Send check orde Solarcraft F)Boxhh2isanta1arhara CA92111 llsalsr Inquirle invitetl 132 Model Aviation 6$ 4 Fast realistic aerobatic kit features ABS wheelpants moUlded canopy pre-bent wire Send $2500 plus $500 shipping to
Edition: Model Aviation - 1981/07
Page Numbers: 59, 60, 61, 62, 132
Model tne 19 Tooth would have much leverage cause warps small patches created same reason important cement Mylar applied fuselage stabilizer structural members comes contact formers diagonals ribs sparsrather just around edges torsional forces fuselage stab great enough warrant use silkspan its increased weight hazards building light possibility going too far building too weak lighter plane faster will climb under power Since lift drag proportional square velocity stress directly proportional lift drag stresses will increase square velocity Simply lighter plane stronger needs rewards successfully building light substantial example 20-ox plane accelerates upwards 50% faster same plane weighing 26 oz based 60-ox thrust mention slower rate glide descent recognize critical flight stresses wing vulnerable because planes lift drag forces acting Flexural torsional flutter singly com bination fixed divergence can occur flexural motion change dihedral resisted wing spars whereas torsional motion twisting action resisted geodetic ribs covering material trailing half airfoil inherently weaker leading half because thinner Therefore neutral bending axis generally parallel chord line downwardly inclined front somewhat wing flexes toward dihedral tends toward washout bends neutral axis will cause diving tendancy high speed wing flexes some degree stabilizer also flexes like amount effects neutralizes other constant angular difference maintained Therefore wing stab should have approximately match ing stresses Since forces stabilizer relatively low stab lift drag per square inch area less half wing stab construc tion should made very light compared wing light stab helps other ways too permits short nose moment engine pulled up under leading edge wing good stability under power Also light stab tail end general reduces planes moment inertia improve glide through responsive maintenance constant angle attack choppy air Construction wing built two halves top piece box spar turbulator spars left off inboard panels Also leave out five center ribs Note two halves joined two diamond-shaped 1/64 plywood pieces top other bottom Epoxy two halves together proper angle lower 1/64 plywood piece place After has set add five center ribs -in center webs upper 1/64 plywood piece Finally add top pieces box spar side webs complete box Cover wing medium-weight silkspan three coats dope best build washin washout like doesnt get done confess rig wing bent paper clips string tied workshop ceiling twist wing weights doping silkspan After dope has cured criss-cross top bottom wing -in Mylar tape following pattem geodetic ribs Now cover wing -mil Mylar Stick wing outline criss-crossed tape use Quik Stik brand contact cement made Coverite purpose sure overlap Mylar onto itself -in seams Put about dozen pin pricks top bottom wing relieve hot air shrinking Mylar Ive best results doing shrinking job steps using heat-sealing iron90% first day balance over two-week period Set warps go shrink Mylar Periodically thereafter check warps pull back should drift wing will take permanent set ages Spray front one-third top wing stab very very lightly fast-drying enamel give some turbulation roughness Mylar Spray several feet away spray particles partially dry before landing will give somewhat rough finish light slow-gliding plane top boundary layer may need energized bitas provided paint texture 60 Model Aviation Author peaks out engine prior launch Note tweaking being done climbing atti tude maximum rigidity wing covered silkspan A-mu Mylar TWO A-H-U Tootflplckstfle authorat Iett son jim right ne autnortooKTIrst iass U upen gg Nats first Class Open i980 Nats Article has valuable tips D4ASIEU1 ~ %OFHA CAP OF H IP NT H H EL B SO D-D II 2 SAWH nH /9 \ j C C-c CHABBOL LEFT FULL LINE PIHCEE1 FOAM ______________________________________WINE BLOB L7 I--— 3 LEFTIIi~TAN NSF TOPUHOT 1% BEWOLATTACH PUILA INST BR EL LABIABIABAHOLE OPPOELEL OH FLHElSE IO CHOSE CALEB E,5 SHEET THEL hAL P11CC HOETHACROSS CHAIN 2 4 UL EACH OF 34 AS4E P/FWE ALTALLS BELAW A/HEHPLLTLBBL I/0E0EPHOCEI------IPTfI7r EWEfl---ETF2F3IIF4--I%SEBIECLET HEFIECTER TNI.BIIII STLCH AB THET LIWEpS~jAj~EEC ALBA /L4 PLY BOLl 3/ 5~~iJR1Xr1EE0 LHINTBNCA PEECESTHALOB FOCI LIAL~2WASHFHBATLILH.ALEILL ABBAT2 PU BA FL AL BA L4 PITBA4 PIToELTHAC HEAL WALL EN 3WLSH OOT~H TOICO ELLABLABLO O-T ETNIAC STOPCOT B BLAB1BLLAT LAB EJAUI BBBHN TTINEB B C F FS-FFTF2 ____ df~F3F4Fl IT 0/OL SLEETS4 SB0 0/4WILE LOEBO LOAP TEN BT TEENEN ETNEAL DAMART FOCAl TIHEB-OT TIMELHNCBOP TOLL EChO LOFT BALSA FHCM LIHEANIL TB TLIS PHI NT POACH BOB TBABA EISLEEFBE EENEAOSEE HEAL BACH ELIOT SO EN ETCH AREA TEL LB IA HEAL NENFOEI BS SIAPIEB ILBEARITAMIC SPEALL LENA AENLBIETI REbUT FOSELOCESC EC/ALH IA HI CT HEAL TCH TOTAl L/OIL ELI NOTE NE HISHE NCBE BELA MN LEO TI RH TOP SPAB FOECLALEL STABLILUT COATTET CROAB BOLLO CEBERILLHIHLMLBIOM WI LELALPON WITH TANEE ECOTE LT HOPE F/C OIL AFLAL OHENALL ETANE NIL MYLAR FLSLLOE EAPAHESE TISSUE COLA WHOA PART MEL HYENA ACT OPEN WOBA HAL A13C TOOTHPICKS BY GAL ELNORRES 070 MELEE WIRE LANBIMO BEAN FOB BEN IASF 9F 2345678 / /7/ 4A BIGHT BEEBE PIT ALLOT Bj SB ALL RB 1 C m z C, w m C, m m m 0 0 Build bottom fuselage surface first pinned directly plans add formers Off side cut top two longerons taper ends join rear cement together Place sub-assembly onto formers pulling longerons conform same contour bottom cement top corners formers diagonals can put last after assembly removed board Use epoxy slow curing kind cement wing center section together fasten firewall 1/64 plywood shield around 1/16 plywood stab rest l back stab other cement work done model airplane glue dont key wing stab alignment preferring eyeball before flight K&B 325 35 use 8 x 4 Zinger old style Master Screw prop 60% nitro fueL Flying Note trim adjustments shown plans plane should go almost straight up gentle twist right transition top gradual left glide turn should transition perfectly 3-sec engine run Best results delaying auto-stab lift two seconds after engine cutoff airplane important engine flying style An engine starts easily within couple flips advantage Invariably stubborn engine will upset timing cause delay launch will put down air back side thermal Odds against maxing between hours 10 12 am have stung too may downers during hours coinci dental theorize normal day thermal activity progresses something like following During night temperatures equalize early morning hours no temperature differences produce vertical air movement air cool dense favorable maxing thermal assistance Get first flight early possible However sun heats earths surface temperature differences generated starting thermal activity time should have maxed out ready flyoffs patient Open fields highways runways readily absorb suns rays Areas foliage such woods cornfields soy bean fields heavy grass-covered fields effectively insulated suns raysthere fore absorb heat slowly open fieldssuch likely flying What means surfaces open fields remain cool suns heat easily absorbed mass earth top surfaces foliage foliage-covered areas heat up quickly because heat readily conducted away Standing thermals form over foliage-cov ered areas standing downers prevail over open fields condition per sists roughly between 10 12 oclock isnt say no thermals over flying field 10 12 Thermal bubbles neighboring fields will blown over during time superimposed will standing downer makes air picking particularly tricky sta tistically unfavorable suppose enterprising could win consistently flying over cornfields woods during hours Finally surface open fields heat up earths crust has heated Its temperature approaches surfaces surround ing foliage-covered areas time say between 12 2 different picture develops Dark rough areas such macadam freshly plowed fields still absorb heatwhile lighter areas such concrete runways light tan hard dirt fields up temperature now heating surface air producing thermals Barring other weather factors now time flyoffs starting about 1 oclock about 2 &clock later process much reverse what 10 12 surfaces black-top areas have become hotter anything around foliage areas still fully up temperature suns heat being slowly drawn away still-cool earth undemeath Therefore afternoon flying field tends produce standing thermals surrounding areas tend produce stand ing downers condition becomes particularly apparent late afternoon eveningup perhaps midnightwhen hot fields give up stored heat cooling air foliage-covered areas have less stored heat return atmosphere discussion somewhat idealized because ignores larger air movements fronts cloud coverage etc contest day dawns clear forecast fair calm day watch conditions occur forecast otherwise static conditions will develop less apparent other dynamic weather factors superimposed confuse Continued page 132 62 Model Aviation uuun aneaa inc riooa-orr rimer pincnes ruci iine opposite side pusneananoy ror quick starts Landing gear captured between engine backplateand through beam mounting holes Upper rubberband released engine timer holds string going stab dowel Lower rubberband holds dethermalizer timer switch position Bottom string holding stab dowel released engine timer allow stab lift glide position Top string holding auto-stab arm later released bythedethermalizertimerto allow stabilizer swing up dethermalized position Stab covered 1/2-mil Mylar 3 ounces fuel rarely needs plug runs kind fuel Ive tried sorts synthetics castor nitro percentages 5-60% engine seems prefer around 20% oil 15% Klotz 5% castor goes faster addition nitro case some engines nitro means sensitive needle settings blown plugs some times less power until head clearance/shape changed Maximum power motor limited because still has rather small stock venturi Just what always wanted Monoboom SP SP stands Speed Pattern event might catch some day Its tried various parts country already fixed series loops eights level flight total elapsed time what counts think trying AMA Stunt Pattern about two half minutes SP plane will larger set up rear exhaust engines like K&B Tigre 40 straight pipe talking lots horsepower like 130mph-producing horsepower Proponents say event future non-destructive measure pilot skill model/engine perfor mance Whatever happened lady luck come FAI Combat Team Trials arent Nationals like other CL events guess main reason amd tell people Combat program well organized locked before Nats location became real possibility Stunt/Team Race Speed nothing firmed up able change Nationals location time Editors note Since written Stunt finals have also moved Natsto Dayton OH Labor Day weekend Lets hope planning great facilities Nashville make up extra travel expense bonus having Combat portion separate added publicity Combat will receive Charlie Johnson 3716 Ingraham St San Diego CA 92109 A-B-C Toothpicks/Morris Continued page 62 picture Speaking weather forecasts certain old almanac folklore sayings general ly true helpful some like Red night sailors delight Red morning sailors take waming Rain before 7 ends before 11 smoke descends good weather ends Sharp horns meaning unusually clear points partial moon threaten high winds Rain long foretold long last short notice soon past Fair weather guides Rising smoke indicates high barometric pressurethus clear day Dew sign fair day No matter ominous appear high clouds wont rain Foul weather guides Sun moon halos indi cate coming rain leaves turn over show backs rain its way storm clouds appear west northwest usually indicates storm will reach Storms south go past Put together plane engine flying styleand bound tough competi tor However slow process Allow year bring new plane up full potential Happy landings FF Scale/Warner Continued page 63 model flew 1981 Astro-Flight Model Builder Champs has 3/16-in aluminum tubing drive shaft going back prop motor cockpit area Bits thin Teflon sheet surplus store punched out tubing OD bracketed Ambroid giue places tubing passed through bulkheads its way rearward took vibration out shaft very nicely Glue wont stick Teflon will hold place smeared around over edges squares cut just little larger 3/16 hole center probably could have eliminated break bronze bearing half way back shaft used attempt steady didnt job eliminating vibrationbut Teflon did few planes props halfway back fuselage such Joe Tschirgis famous DuFaux amaze people cant see whole rear plane doesnt revolve too Vancouver BC correspondent artist Dick Allen gives away secret electricmotor-driven conception its done Quite simply long stationary shaft ties front back fuselage together prop shaft really free-spinning tube fits over non-moving structural member spun belt gears great job electric thinking shaft-drive plane just remember keep light can try support drive shaft intervals keep shake out try keep shaft motor line Minor bends drive line can accomplished using Hungerford method wound music wire spring point direction-change provide needed flexibility Having used PATTERN AND 004 HIGH SPEED PROPELLERS AIRSCREW CUSTOM HIGH PERFORMANCE MAPLE PROPELLERS Propeller designed usin2 symmetrical profile Individually precision hand balanced Accurale airfoil pitch Only high quality straight grain Eastern Maple used a% x 6% FORMULA 1 iox S lix 11X712 iixs CUSTOM DESIGN UPON REQUE ST OrRECT SALES mv 5634 CRYSTAL COAST SANTA ROSA CA SSAAA PRONE 707 SOSSODA Add RIDS pe dR POStage handling CA DES ADO 5% TAA TLC R/C PRODUCTS Rt 1 Box 282 Prospect VA 23901 Solareraft presents 2 new fun flyers Betas DesS 12 rubber powered helicopter climbs over 250 $300 postage paid ready fly Belar Scamp 12 high performance free flying stick model $400 postage paid ready fly Send check orde Solarcraft F)Boxhh2isanta1arhara CA92111 llsalsr Inquirle invitetl 132 Model Aviation 6$ 4 Fast realistic aerobatic kit features ABS wheelpants moUlded canopy pre-bent wire Send $2500 plus $500 shipping to
Edition: Model Aviation - 1981/07
Page Numbers: 59, 60, 61, 62, 132
Model tne 19 Tooth would have much leverage cause warps small patches created same reason important cement Mylar applied fuselage stabilizer structural members comes contact formers diagonals ribs sparsrather just around edges torsional forces fuselage stab great enough warrant use silkspan its increased weight hazards building light possibility going too far building too weak lighter plane faster will climb under power Since lift drag proportional square velocity stress directly proportional lift drag stresses will increase square velocity Simply lighter plane stronger needs rewards successfully building light substantial example 20-ox plane accelerates upwards 50% faster same plane weighing 26 oz based 60-ox thrust mention slower rate glide descent recognize critical flight stresses wing vulnerable because planes lift drag forces acting Flexural torsional flutter singly com bination fixed divergence can occur flexural motion change dihedral resisted wing spars whereas torsional motion twisting action resisted geodetic ribs covering material trailing half airfoil inherently weaker leading half because thinner Therefore neutral bending axis generally parallel chord line downwardly inclined front somewhat wing flexes toward dihedral tends toward washout bends neutral axis will cause diving tendancy high speed wing flexes some degree stabilizer also flexes like amount effects neutralizes other constant angular difference maintained Therefore wing stab should have approximately match ing stresses Since forces stabilizer relatively low stab lift drag per square inch area less half wing stab construc tion should made very light compared wing light stab helps other ways too permits short nose moment engine pulled up under leading edge wing good stability under power Also light stab tail end general reduces planes moment inertia improve glide through responsive maintenance constant angle attack choppy air Construction wing built two halves top piece box spar turbulator spars left off inboard panels Also leave out five center ribs Note two halves joined two diamond-shaped 1/64 plywood pieces top other bottom Epoxy two halves together proper angle lower 1/64 plywood piece place After has set add five center ribs -in center webs upper 1/64 plywood piece Finally add top pieces box spar side webs complete box Cover wing medium-weight silkspan three coats dope best build washin washout like doesnt get done confess rig wing bent paper clips string tied workshop ceiling twist wing weights doping silkspan After dope has cured criss-cross top bottom wing -in Mylar tape following pattem geodetic ribs Now cover wing -mil Mylar Stick wing outline criss-crossed tape use Quik Stik brand contact cement made Coverite purpose sure overlap Mylar onto itself -in seams Put about dozen pin pricks top bottom wing relieve hot air shrinking Mylar Ive best results doing shrinking job steps using heat-sealing iron90% first day balance over two-week period Set warps go shrink Mylar Periodically thereafter check warps pull back should drift wing will take permanent set ages Spray front one-third top wing stab very very lightly fast-drying enamel give some turbulation roughness Mylar Spray several feet away spray particles partially dry before landing will give somewhat rough finish light slow-gliding plane top boundary layer may need energized bitas provided paint texture 60 Model Aviation Author peaks out engine prior launch Note tweaking being done climbing atti tude maximum rigidity wing covered silkspan A-mu Mylar TWO A-H-U Tootflplckstfle authorat Iett son jim right ne autnortooKTIrst iass U upen gg Nats first Class Open i980 Nats Article has valuable tips D4ASIEU1 ~ %OFHA CAP OF H IP NT H H EL B SO D-D II 2 SAWH nH /9 \ j C C-c CHABBOL LEFT FULL LINE PIHCEE1 FOAM ______________________________________WINE BLOB L7 I--— 3 LEFTIIi~TAN NSF TOPUHOT 1% BEWOLATTACH PUILA INST BR EL LABIABIABAHOLE OPPOELEL OH FLHElSE IO CHOSE CALEB E,5 SHEET THEL hAL P11CC HOETHACROSS CHAIN 2 4 UL EACH OF 34 AS4E P/FWE ALTALLS BELAW A/HEHPLLTLBBL I/0E0EPHOCEI------IPTfI7r EWEfl---ETF2F3IIF4--I%SEBIECLET HEFIECTER TNI.BIIII STLCH AB THET LIWEpS~jAj~EEC ALBA /L4 PLY BOLl 3/ 5~~iJR1Xr1EE0 LHINTBNCA PEECESTHALOB FOCI LIAL~2WASHFHBATLILH.ALEILL ABBAT2 PU BA FL AL BA L4 PITBA4 PIToELTHAC HEAL WALL EN 3WLSH OOT~H TOICO ELLABLABLO O-T ETNIAC STOPCOT B BLAB1BLLAT LAB EJAUI BBBHN TTINEB B C F FS-FFTF2 ____ df~F3F4Fl IT 0/OL SLEETS4 SB0 0/4WILE LOEBO LOAP TEN BT TEENEN ETNEAL DAMART FOCAl TIHEB-OT TIMELHNCBOP TOLL EChO LOFT BALSA FHCM LIHEANIL TB TLIS PHI NT POACH BOB TBABA EISLEEFBE EENEAOSEE HEAL BACH ELIOT SO EN ETCH AREA TEL LB IA HEAL NENFOEI BS SIAPIEB ILBEARITAMIC SPEALL LENA AENLBIETI REbUT FOSELOCESC EC/ALH IA HI CT HEAL TCH TOTAl L/OIL ELI NOTE NE HISHE NCBE BELA MN LEO TI RH TOP SPAB FOECLALEL STABLILUT COATTET CROAB BOLLO CEBERILLHIHLMLBIOM WI LELALPON WITH TANEE ECOTE LT HOPE F/C OIL AFLAL OHENALL ETANE NIL MYLAR FLSLLOE EAPAHESE TISSUE COLA WHOA PART MEL HYENA ACT OPEN WOBA HAL A13C TOOTHPICKS BY GAL ELNORRES 070 MELEE WIRE LANBIMO BEAN FOB BEN IASF 9F 2345678 / /7/ 4A BIGHT BEEBE PIT ALLOT Bj SB ALL RB 1 C m z C, w m C, m m m 0 0 Build bottom fuselage surface first pinned directly plans add formers Off side cut top two longerons taper ends join rear cement together Place sub-assembly onto formers pulling longerons conform same contour bottom cement top corners formers diagonals can put last after assembly removed board Use epoxy slow curing kind cement wing center section together fasten firewall 1/64 plywood shield around 1/16 plywood stab rest l back stab other cement work done model airplane glue dont key wing stab alignment preferring eyeball before flight K&B 325 35 use 8 x 4 Zinger old style Master Screw prop 60% nitro fueL Flying Note trim adjustments shown plans plane should go almost straight up gentle twist right transition top gradual left glide turn should transition perfectly 3-sec engine run Best results delaying auto-stab lift two seconds after engine cutoff airplane important engine flying style An engine starts easily within couple flips advantage Invariably stubborn engine will upset timing cause delay launch will put down air back side thermal Odds against maxing between hours 10 12 am have stung too may downers during hours coinci dental theorize normal day thermal activity progresses something like following During night temperatures equalize early morning hours no temperature differences produce vertical air movement air cool dense favorable maxing thermal assistance Get first flight early possible However sun heats earths surface temperature differences generated starting thermal activity time should have maxed out ready flyoffs patient Open fields highways runways readily absorb suns rays Areas foliage such woods cornfields soy bean fields heavy grass-covered fields effectively insulated suns raysthere fore absorb heat slowly open fieldssuch likely flying What means surfaces open fields remain cool suns heat easily absorbed mass earth top surfaces foliage foliage-covered areas heat up quickly because heat readily conducted away Standing thermals form over foliage-cov ered areas standing downers prevail over open fields condition per sists roughly between 10 12 oclock isnt say no thermals over flying field 10 12 Thermal bubbles neighboring fields will blown over during time superimposed will standing downer makes air picking particularly tricky sta tistically unfavorable suppose enterprising could win consistently flying over cornfields woods during hours Finally surface open fields heat up earths crust has heated Its temperature approaches surfaces surround ing foliage-covered areas time say between 12 2 different picture develops Dark rough areas such macadam freshly plowed fields still absorb heatwhile lighter areas such concrete runways light tan hard dirt fields up temperature now heating surface air producing thermals Barring other weather factors now time flyoffs starting about 1 oclock about 2 &clock later process much reverse what 10 12 surfaces black-top areas have become hotter anything around foliage areas still fully up temperature suns heat being slowly drawn away still-cool earth undemeath Therefore afternoon flying field tends produce standing thermals surrounding areas tend produce stand ing downers condition becomes particularly apparent late afternoon eveningup perhaps midnightwhen hot fields give up stored heat cooling air foliage-covered areas have less stored heat return atmosphere discussion somewhat idealized because ignores larger air movements fronts cloud coverage etc contest day dawns clear forecast fair calm day watch conditions occur forecast otherwise static conditions will develop less apparent other dynamic weather factors superimposed confuse Continued page 132 62 Model Aviation uuun aneaa inc riooa-orr rimer pincnes ruci iine opposite side pusneananoy ror quick starts Landing gear captured between engine backplateand through beam mounting holes Upper rubberband released engine timer holds string going stab dowel Lower rubberband holds dethermalizer timer switch position Bottom string holding stab dowel released engine timer allow stab lift glide position Top string holding auto-stab arm later released bythedethermalizertimerto allow stabilizer swing up dethermalized position Stab covered 1/2-mil Mylar 3 ounces fuel rarely needs plug runs kind fuel Ive tried sorts synthetics castor nitro percentages 5-60% engine seems prefer around 20% oil 15% Klotz 5% castor goes faster addition nitro case some engines nitro means sensitive needle settings blown plugs some times less power until head clearance/shape changed Maximum power motor limited because still has rather small stock venturi Just what always wanted Monoboom SP SP stands Speed Pattern event might catch some day Its tried various parts country already fixed series loops eights level flight total elapsed time what counts think trying AMA Stunt Pattern about two half minutes SP plane will larger set up rear exhaust engines like K&B Tigre 40 straight pipe talking lots horsepower like 130mph-producing horsepower Proponents say event future non-destructive measure pilot skill model/engine perfor mance Whatever happened lady luck come FAI Combat Team Trials arent Nationals like other CL events guess main reason amd tell people Combat program well organized locked before Nats location became real possibility Stunt/Team Race Speed nothing firmed up able change Nationals location time Editors note Since written Stunt finals have also moved Natsto Dayton OH Labor Day weekend Lets hope planning great facilities Nashville make up extra travel expense bonus having Combat portion separate added publicity Combat will receive Charlie Johnson 3716 Ingraham St San Diego CA 92109 A-B-C Toothpicks/Morris Continued page 62 picture Speaking weather forecasts certain old almanac folklore sayings general ly true helpful some like Red night sailors delight Red morning sailors take waming Rain before 7 ends before 11 smoke descends good weather ends Sharp horns meaning unusually clear points partial moon threaten high winds Rain long foretold long last short notice soon past Fair weather guides Rising smoke indicates high barometric pressurethus clear day Dew sign fair day No matter ominous appear high clouds wont rain Foul weather guides Sun moon halos indi cate coming rain leaves turn over show backs rain its way storm clouds appear west northwest usually indicates storm will reach Storms south go past Put together plane engine flying styleand bound tough competi tor However slow process Allow year bring new plane up full potential Happy landings FF Scale/Warner Continued page 63 model flew 1981 Astro-Flight Model Builder Champs has 3/16-in aluminum tubing drive shaft going back prop motor cockpit area Bits thin Teflon sheet surplus store punched out tubing OD bracketed Ambroid giue places tubing passed through bulkheads its way rearward took vibration out shaft very nicely Glue wont stick Teflon will hold place smeared around over edges squares cut just little larger 3/16 hole center probably could have eliminated break bronze bearing half way back shaft used attempt steady didnt job eliminating vibrationbut Teflon did few planes props halfway back fuselage such Joe Tschirgis famous DuFaux amaze people cant see whole rear plane doesnt revolve too Vancouver BC correspondent artist Dick Allen gives away secret electricmotor-driven conception its done Quite simply long stationary shaft ties front back fuselage together prop shaft really free-spinning tube fits over non-moving structural member spun belt gears great job electric thinking shaft-drive plane just remember keep light can try support drive shaft intervals keep shake out try keep shaft motor line Minor bends drive line can accomplished using Hungerford method wound music wire spring point direction-change provide needed flexibility Having used PATTERN AND 004 HIGH SPEED PROPELLERS AIRSCREW CUSTOM HIGH PERFORMANCE MAPLE PROPELLERS Propeller designed usin2 symmetrical profile Individually precision hand balanced Accurale airfoil pitch Only high quality straight grain Eastern Maple used a% x 6% FORMULA 1 iox S lix 11X712 iixs CUSTOM DESIGN UPON REQUE ST OrRECT SALES mv 5634 CRYSTAL COAST SANTA ROSA CA SSAAA PRONE 707 SOSSODA Add RIDS pe dR POStage handling CA DES ADO 5% TAA TLC R/C PRODUCTS Rt 1 Box 282 Prospect VA 23901 Solareraft presents 2 new fun flyers Betas DesS 12 rubber powered helicopter climbs over 250 $300 postage paid ready fly Belar Scamp 12 high performance free flying stick model $400 postage paid ready fly Send check orde Solarcraft F)Boxhh2isanta1arhara CA92111 llsalsr Inquirle invitetl 132 Model Aviation 6$ 4 Fast realistic aerobatic kit features ABS wheelpants moUlded canopy pre-bent wire Send $2500 plus $500 shipping to