NO OCR TEXT NO OCR TEXT Author-designer-builder Bob Owens poses prior start local Sailplane Contest standard models Note slender fuselage generous tail moment arm Airfoil undercambered Eppler 387 Hard balsa plywood speci fied experience has told wasnt quite strong enough Avoid use epoxy doesnt evaporate reduce weight Instead use aliphatic resin thinned about 30% water Use sparing ly double-glue high-stress areas suggest make apolicator small squeeze-bottle such Zaptpflon tube can layof glue get ti tail surfaces 54it wood except SI S4 balsa Resist temptatior substituting larger yr really much nree arneren versions Zephyr view Headed straight us first conventional tapered wing Number 2 subject article Red Job heavyweight 13 oz imagined Anyway repairs quickly easilybeen covered 280-grit wet-or-dry sandpaper Follow plans least first oneattached Supertape sandpaper holds place cutting straight edges sheet balsa Preplanniag Before starting construction layand cutting strip wood out radio plansboth side bottom viewsto assure will fit Compare theConstruction suggest getting dull w width index finger sure will fit inof way enthusiasm ri finger notch may wish adjust theyou havent built Peanut Sc fuselage size less depending thelately now time get inL width radio finger Now time tobuilding light Use new No 11 make decision little ii ace foron soft wood get clean cut foam padding around receiver ry soit isnt anything unusui better leave plastsurfaces except fin ar Make upakitofparts Youvedge LE kept ng long straight cut uscovering Bevel aluminum has truepermit least 30 14EY PW NJOThEP Rs OSF~RII 3/32X 1/4 BALSA 3/8DIA LJ3-ITENING HOLES/IFOR ALL FlN-RUER FRAMES 3/32X V2 SHEET13/32 SQ BRACES FIN BRACES /32 SHEET BALSALEADINGEOGE SPANS CENTER 10P BOTTOM C CENTER SECTION I/32PLYflO CENTER DIHEDRAL BRACENO4 3/B SCREW3/32X /4 HARD BALSA SFR I/4 20 NYLON BOLT THRU BALSA BLOCK HOLD DOWN OVER V32PLW FORNER I/16X /4 HARD BALSA SPARS TOP/BOTTOM VBX I/2SHEET BALSA TRAIUNG EDGE AND TIP 1/32 PLOD1/4 BALSA SERVO BLOCKSI/64PLtwOo FUSELAGEI/B X 1/4 BALSA1/32 PLYWCO BRACE1/32 SHEET BALSA CWERS DOUBLER AT GRIP AREALEADING EDGESSPANS TIP DIHEDRALLEADING EDGE TOP AM BOTTOM SOLID NOSE BLOCKI/BX T/8BOTTOM FIlL LENGTHCUT OUT BOTTOM FOR INDEX FINGER FULL-SIZE PLANS AVAILABLE. SEE PAGE 132 5/52 SPAR-WOWOW-- W7 -.- . n-r4 _____ BALSAWRAWH VERTICAlwir SOWIWASPARSWEBN IA ROLE 2W2WZWI_WI N10 01/2 TE STOCK WAILD WWA SAME AS IOil{jREj~1FLAT NOTTOW ERCEPT sSTICK WONOKOTE TO IoTo L~7iWAJV~ALATTEACH OW AFTER SHBIMKNW IIWREORAL BRACES S-~1/52 NOTES ALL RALSA PARTS CONTEST GRADE SOFT ERCEPT WINO & ELED SPARS SI & OH ARE WARS FOR H 2 BALANCE LEVEL AT WING BOLT J FD FBNO205W SCREW WOOWED PAPER CUP OPTORAL TOW HOOK WN OWEN 0 BA ENDEO-N-BOOSSALUGAN NO SOi1 WADDER ELEG HOIRN I/IN PLO/bITS 3/02 ITjRECEIDER OoER%\At FI4JF5Nj~j7-TB I/HF I/NO PlO DOSBIERFA FUSE SIDES 5/52FID FIN ssoBONOGOTE GINHES TI5/FI SERVO WLOCKS FINOER WESTISOTUNRO WEIIDATLIWED OT NO CONDAIT I/A S D/W ANOER NDTH-COTaIT FBI SODA STRAW IWING SPAN021K AFTER FOSE ISAOGEBWAKDP WA WOLEIRI FFR FASE BOTTOM 12WWINOAREA330 ODIN FFRAIOATLINED 851WEIGAT LASS WADE 5 00 AIRFOIL EPPLER 5W FWI/R_____________ IOI-I/HSI-5/ARRLGANDOERLDCK5/SD O5FANFIILFSFN SOAWLERSz 1/52 PLY CUTWWGT EDDESIGNED ADRAWNWT WOW OWENS TO FIT F direction elevator similarily beveled Wing Pin down lower spar wing outer rib dihedral break Add vertical least same travel Notch rudder panel blocking up 1/32-in allow shear webbing dihedral brace Finish off elevator accept control horns Leave sheeting later LE also blocked up adding top spar Wet spar last rib tail structure pinned-down ample time height ribs Pin down trailing edge TE facilitate bending down tip glue set up hard tip glue ribs place except omit Continued page 98 20 Model Aviation WITfl ama DU155 spars EflO one-piece wing strongthanks shear webs fully sheeted leading edge forms rigid structural box Tail surfaces fragile adequate ..hors completed framework ready cover weIghed 3 02 wIthout radio Careful weight control needed prevent climbing 502 Use thinned aliphatic resin sparingly pre-sand balsa parts Author refers fuselage building half-shell Kraft KPS 18 servos built mounted screws permit easy removal Note routing control rods antenna conduit Theres ample space 6-ch Kraft receiver skinny case 225 mAh batterywith case bantamsize servos Fuselage width can bevaried accommodate own radio componentswithin reason FUN SCALE IS ilERE Easier Fly Yet Very Maneuverable Over 20 step-by-step building illustrations easier follow photos Lands Like Trainer Ideal 2nd Trainer Novice 19-25 Engine 19-40 Eng Span 51 Area 490 sq 18-20 oz wing loading 3*-4 lbs Upright Engine Can Built Flown 7 Days Due New Construction Techniques WILL FLY AS SLOW AS PIPER CUB MODEL Write free Catalog JEMCO 1305 Foothill Dr Vista CA 92083 714 724-3242 Zephyr Owens Continued page 20 Build inner wing panels same man ner join outer panel inner panel just before adding top spar Turn plans over build opposite wing Join right left wing halves first adding center dihedral brace add bolt block center rib cut fitted between LE spar between block TE Add LE sheeting following sequence lower inner panels lower outer panels upper inner panels upper outer panels Next add lower center panel upper center panels Sand weigh sand some Since sheeting usually warped edges must trim off slice straightedge mentioned earlierbefore trying glue wing fuselage will built up half shellso speak insufficient space down inside fuselage much work after boxed Everything possible will completed prior installing left side fuselage Attach doublers F7 F9 inside fuselage side F2 Use Hot Stuff Zap Jet make left right side Throughout instructions will refer Hot Stuff can take pick of cyanoacrylate glues Lay right side over side view plans glue place nose block Fl formers F3 F4A F4B F5 fuselage tapers between F3 FS width cross members must carefully measured achieve good fit left side put place Before gluing parts place lay straightedge across F3 F4 F4 F5to sure have good fit Add servo mounting blocks F14 F15 F16 F17 spaced according specific servos Again test fit using straightedge prefer servo tape can omit blocks Add parts make up cavity finger notch Fli F12 F13 Install servos add rudder elevator pushrod housings Gold-N-Rod #507 Attach hous ings right side 3 using baking soda Hot Stuff Make up pushrod cable-end-fitting Z-clips using soft wiresuch paper clipsof proper diameter fit holes servo arms Cut pieces copper tubing 5/16-in long Gold-N-Rod solder Z-clips forward end pushrod cables solder aft end fittings until final assembly Now excellent time test direction servo rotation pushrod travel sure rudder elevator move proper direction usually get wrong least control time Kraft System use dot servo rudder control install behind wing bolt because receiver has pigtail aileron connector negates possible need servo cable extender elevator servo standard no dot complete fuselage half-shell add 3/32 sq balsa strips F3 left right fuselage sides between wing tail Trial-fit soda straw cocktail straw fuselage serve antenna conduit Bevel aft end side tail post Glue left fuselage side place directly over right side except tail post using modeling clamps hold square Glue fuselage bottom F8 bring sides together tail post bottom fits between sides serves align entire fuselage straight true Install antenna conduit using Hot Stuff Continued page 102 ALL parts cut shape 0 Unique wing construction eliminates dihedral braces wing sheeting DesIgned Iron-on coverings Bottom view rear end shows rudder pushrod cable end fitting rudder notched passage elevator spar receiver antenna exiting soda-straw conduit 1/16 ply rudder horn l3WC QLD THE NEW FIREBALL GLOW PLUGS ARE LEAKPROOF AND BLOWOUT PROOF EVEN FOR THE NEW MONSTER ENGINES BUT THEY ARE STILL THE OLD PRICE OF $110 WRITE NOW! SWANSON P0 Box 151 Wayne NJ 07470 L 98 Model Aviation WINDSOR PROPELLER CO PO Box 112 Windsor CA 95492 Winning Ideas FOURMOST FUEL MANIFOLD o ww o 0 114FUEL SHUT OFFSma Fue Pitting Set Manifold Provides ConvenientCan Used Control Fuel zeI 0PRICE $1 50 Method Tank Filling Draining endFlow Starting1 Tee 2 Elbows 1 Pen Blsdder Tee PrimingPositive Airborn Shutoff % IDPRICE $125PRICE $420 ANDS 00STRUT PAIRINGS Comes two - 23 Lengths cock A- -Th COamingTwo Sizes% 10 s geFue F gS Sze%IDPRCE $200 Packaged 2 Ft Size E ee 1E bowU P g PRICE $250 ngths either size $2 70Bo ii Made oe Fu Send SASE Complete Information FOURMOST 4040 24th Ave Forest Grove OR 97116 PRODUCTS Phone 503 357-2732 baking soda few turns sewing thread necessary Add top hatch hold-down F6 wing TE hold-down F 19 fuselage top sheeting Temporarily install wing using nylon bolt align wing square fuselage install trailing edge screw Glue Fl 9 top hatch F20 carve aft edge fit wing upper surface wing place place straightedge fuselage tail-rest check dihedral alignment between wing horizontal tail Remove shape sand nose block sand fuselage corners have building nothing large models will amazed fast small jobs go together Covering luse MonoKote because its strengthto-weight ratio spend little extra time planning executing multi-colored covering scheme have standardized scheme shown photos white metallic-blue tips splash yellow important bottom omit yellow use blue undersides wing tips horizontal stab/elevator gives excellent visibility variety sky conditions Zephyr gets up nearly out-of-sight hurry color contrast lower surfaces helpful keeping view longer arrange ment provides three points reference helps orienting direction flight pitch climb dive attitude Omit covering tail surfaces g1ued Hinge rudder elevator strip MonoKote least wideattached side opposite beveled edge Leave about 1/16-in space between fixed hinged portions allow freedom movement After MonoKote tightened wings attach undercambered ribs Final assembly Install radio switch top hatch way will leave hatch home left fuselage side just ahead wing above receiver made lightweight switch harness using tiny audio slide switch switches suitable power planes since subject intermit tent operation due vibration Leave out charging jack keep connected charger avoid carrying around extra weight Again install wing glue horizontal tail placewhile carefully aligning wing viewed rear Also note slot stab receive fin must centered fuselage aimed straight-away wing bolt Epoxy yes first time have called epoxy rudder elevator horns place Terminate cable pushrod Z-clips first turn radio center trim knobs rudder elevator surfaces must neutral positions solder end-fit tings place flight trim adjustments necessary longer shorter Z-clips can made up necessary correction Operate servos full-travel sure no binding Now make sure center-of-gravity CG balanced per plans get rid warps -in washout tips good Flying Thermal slope hand-launch mini hi-start take pick Initially suggest go over local park baseball diamond grass ouffield Start some gentle tosses adding little muscle build confidence Also start aim little higher soon will tossing up about 60 degrees getting 50 60 feet altitude top climb have best success stiff-arm toss sling getting waist shoulder keeps throwing arm away Its just like tosing hand grenades back WW II After have throwing down can push over top climb stalling walk over downwind edge bare infield baseball field sun hot relative ground wind blowing just might pick up little thermal breeze blowing best circle S-turnsalways turning winduntil get lift turns too tight will create lots wing lift lots drag same time Keep turns shallow practical wing will contribute altitude gain just going around circles always considered desert great place thermals isnt necessarily desert floor just too regnlar uniformthat unless can find place has few ridges barren spots have relatives live desert first visit after finishing prototype Zephyr took along morning hot clear calm couldnt get anything few wing wiggles occasional bump lift spotted little ditch someone dug lay water pipe foot-high ridge bare dirt took start bubble warm air its way up able work small amount lift generated several minutes time tiring work because have put model exactiy right spot time So much hand-launching desert Just kicks made mini hi-start using 25 102 Model Aviation MASIElI AIRSCRIW FLIGHTBOX KIT Master Airscrew Flight Box has features larger boxes compact handy arrangement parts cut imported mahogany plywood will take stain varnish paint finishes overall size 19Wx9Wx 12 high $ dat dealer postpaid California add 6% Sales Tax Propeller storage Gravity closed small parts storage 7/8 aluminum handle Complete instructions & fasteners FEATURES INCLUDE Space battery & meter panel Transmitter compartment Room gallon fuel ft 3/1 6-in flat rubber 100 ft I0-lb-test fishing line old antenna ribbon streamer place usual parachute optional tow hook shown plan worked very well yeilded better results desert hand-launching am sure would better twice length rubber line Maybe am just lazy Slope Soaring much liking especially late lazy afternoons wind down whisper just few Gliders left slopejust barely scratching out flight Zephyr really shines always last plane forced land can tossed up 50 ft above ridge just gentlest breezes will permit several passes problem very well yielded better results desert because youre still flying cant stay out brush down slope ridge Balance very important gentle forgiving little bird slow flight hand-launching speed range quite broad hand-launching easily going 50 mph launch leaves hand about 10 mph light lift can trimmed both conditions Thought would never ask get balance correct place will trimmed both conditions anything between throw up should go straight rock zooms up have too nose-heavy thats right nose-heavy too tail-heavy will tend arc downward slight dive both cases assumes have model adjusted relatively slow hands-off glide Without getting lengthy aerodynamic discussion extra nose weight causes extra up-elevator trim just keep model level during slow flight throw hard above trim speed up-elevator trim causes nose pull up can also test same thing gliding higher up Start slow-trimmed glide Gradually push nose down hold control stick same position model builds up speed tends pull out dive too nose-heavy dive steepens tail-heavy correct balance should continue same diving attitude started correct balance point Zephyr will loops rolls inverted flight dont expect inverted flight undercambered airfoil good upright flight decent wind slope should able maintain altitude inverted have Zephyr mastered make control surfaces sensitive travel better real fun Radio Technique/Myers Continued page 23 reason judge end-of-charge point voltage small part battery voltage lost across ammeter larger part lost inside battery batteries have internal resistance new AA-size nickle-cadmium battery will show about 035 ohms operating about 75% full charge As charge exhausted resistance increases until reaches about 100 ohms battery shows terminal voltage around 10 VDC numbers look small until consider multiply four get pack resistance add some ohms account welded tabs soldered joints wire plug Figure flight pack will vary depending its state charge Multiply resistance current Continued page 106 May1981 103 Shes surprisingly easy handle. can really get up go. WING SPAN 56 rfster LENGTH 39 WEIGHT 5-6 LBS POWER 40 C0VERITE 420 BABYLON RD 1-IORSHAM PA 19044
Edition: Model Aviation - 1981/05
Page Numbers: 16, 17, 18, 19, 20, 98, 102, 103
NO OCR TEXT NO OCR TEXT Author-designer-builder Bob Owens poses prior start local Sailplane Contest standard models Note slender fuselage generous tail moment arm Airfoil undercambered Eppler 387 Hard balsa plywood speci fied experience has told wasnt quite strong enough Avoid use epoxy doesnt evaporate reduce weight Instead use aliphatic resin thinned about 30% water Use sparing ly double-glue high-stress areas suggest make apolicator small squeeze-bottle such Zaptpflon tube can layof glue get ti tail surfaces 54it wood except SI S4 balsa Resist temptatior substituting larger yr really much nree arneren versions Zephyr view Headed straight us first conventional tapered wing Number 2 subject article Red Job heavyweight 13 oz imagined Anyway repairs quickly easilybeen covered 280-grit wet-or-dry sandpaper Follow plans least first oneattached Supertape sandpaper holds place cutting straight edges sheet balsa Preplanniag Before starting construction layand cutting strip wood out radio plansboth side bottom viewsto assure will fit Compare theConstruction suggest getting dull w width index finger sure will fit inof way enthusiasm ri finger notch may wish adjust theyou havent built Peanut Sc fuselage size less depending thelately now time get inL width radio finger Now time tobuilding light Use new No 11 make decision little ii ace foron soft wood get clean cut foam padding around receiver ry soit isnt anything unusui better leave plastsurfaces except fin ar Make upakitofparts Youvedge LE kept ng long straight cut uscovering Bevel aluminum has truepermit least 30 14EY PW NJOThEP Rs OSF~RII 3/32X 1/4 BALSA 3/8DIA LJ3-ITENING HOLES/IFOR ALL FlN-RUER FRAMES 3/32X V2 SHEET13/32 SQ BRACES FIN BRACES /32 SHEET BALSALEADINGEOGE SPANS CENTER 10P BOTTOM C CENTER SECTION I/32PLYflO CENTER DIHEDRAL BRACENO4 3/B SCREW3/32X /4 HARD BALSA SFR I/4 20 NYLON BOLT THRU BALSA BLOCK HOLD DOWN OVER V32PLW FORNER I/16X /4 HARD BALSA SPARS TOP/BOTTOM VBX I/2SHEET BALSA TRAIUNG EDGE AND TIP 1/32 PLOD1/4 BALSA SERVO BLOCKSI/64PLtwOo FUSELAGEI/B X 1/4 BALSA1/32 PLYWCO BRACE1/32 SHEET BALSA CWERS DOUBLER AT GRIP AREALEADING EDGESSPANS TIP DIHEDRALLEADING EDGE TOP AM BOTTOM SOLID NOSE BLOCKI/BX T/8BOTTOM FIlL LENGTHCUT OUT BOTTOM FOR INDEX FINGER FULL-SIZE PLANS AVAILABLE. SEE PAGE 132 5/52 SPAR-WOWOW-- W7 -.- . n-r4 _____ BALSAWRAWH VERTICAlwir SOWIWASPARSWEBN IA ROLE 2W2WZWI_WI N10 01/2 TE STOCK WAILD WWA SAME AS IOil{jREj~1FLAT NOTTOW ERCEPT sSTICK WONOKOTE TO IoTo L~7iWAJV~ALATTEACH OW AFTER SHBIMKNW IIWREORAL BRACES S-~1/52 NOTES ALL RALSA PARTS CONTEST GRADE SOFT ERCEPT WINO & ELED SPARS SI & OH ARE WARS FOR H 2 BALANCE LEVEL AT WING BOLT J FD FBNO205W SCREW WOOWED PAPER CUP OPTORAL TOW HOOK WN OWEN 0 BA ENDEO-N-BOOSSALUGAN NO SOi1 WADDER ELEG HOIRN I/IN PLO/bITS 3/02 ITjRECEIDER OoER%\At FI4JF5Nj~j7-TB I/HF I/NO PlO DOSBIERFA FUSE SIDES 5/52FID FIN ssoBONOGOTE GINHES TI5/FI SERVO WLOCKS FINOER WESTISOTUNRO WEIIDATLIWED OT NO CONDAIT I/A S D/W ANOER NDTH-COTaIT FBI SODA STRAW IWING SPAN021K AFTER FOSE ISAOGEBWAKDP WA WOLEIRI FFR FASE BOTTOM 12WWINOAREA330 ODIN FFRAIOATLINED 851WEIGAT LASS WADE 5 00 AIRFOIL EPPLER 5W FWI/R_____________ IOI-I/HSI-5/ARRLGANDOERLDCK5/SD O5FANFIILFSFN SOAWLERSz 1/52 PLY CUTWWGT EDDESIGNED ADRAWNWT WOW OWENS TO FIT F direction elevator similarily beveled Wing Pin down lower spar wing outer rib dihedral break Add vertical least same travel Notch rudder panel blocking up 1/32-in allow shear webbing dihedral brace Finish off elevator accept control horns Leave sheeting later LE also blocked up adding top spar Wet spar last rib tail structure pinned-down ample time height ribs Pin down trailing edge TE facilitate bending down tip glue set up hard tip glue ribs place except omit Continued page 98 20 Model Aviation WITfl ama DU155 spars EflO one-piece wing strongthanks shear webs fully sheeted leading edge forms rigid structural box Tail surfaces fragile adequate ..hors completed framework ready cover weIghed 3 02 wIthout radio Careful weight control needed prevent climbing 502 Use thinned aliphatic resin sparingly pre-sand balsa parts Author refers fuselage building half-shell Kraft KPS 18 servos built mounted screws permit easy removal Note routing control rods antenna conduit Theres ample space 6-ch Kraft receiver skinny case 225 mAh batterywith case bantamsize servos Fuselage width can bevaried accommodate own radio componentswithin reason FUN SCALE IS ilERE Easier Fly Yet Very Maneuverable Over 20 step-by-step building illustrations easier follow photos Lands Like Trainer Ideal 2nd Trainer Novice 19-25 Engine 19-40 Eng Span 51 Area 490 sq 18-20 oz wing loading 3*-4 lbs Upright Engine Can Built Flown 7 Days Due New Construction Techniques WILL FLY AS SLOW AS PIPER CUB MODEL Write free Catalog JEMCO 1305 Foothill Dr Vista CA 92083 714 724-3242 Zephyr Owens Continued page 20 Build inner wing panels same man ner join outer panel inner panel just before adding top spar Turn plans over build opposite wing Join right left wing halves first adding center dihedral brace add bolt block center rib cut fitted between LE spar between block TE Add LE sheeting following sequence lower inner panels lower outer panels upper inner panels upper outer panels Next add lower center panel upper center panels Sand weigh sand some Since sheeting usually warped edges must trim off slice straightedge mentioned earlierbefore trying glue wing fuselage will built up half shellso speak insufficient space down inside fuselage much work after boxed Everything possible will completed prior installing left side fuselage Attach doublers F7 F9 inside fuselage side F2 Use Hot Stuff Zap Jet make left right side Throughout instructions will refer Hot Stuff can take pick of cyanoacrylate glues Lay right side over side view plans glue place nose block Fl formers F3 F4A F4B F5 fuselage tapers between F3 FS width cross members must carefully measured achieve good fit left side put place Before gluing parts place lay straightedge across F3 F4 F4 F5to sure have good fit Add servo mounting blocks F14 F15 F16 F17 spaced according specific servos Again test fit using straightedge prefer servo tape can omit blocks Add parts make up cavity finger notch Fli F12 F13 Install servos add rudder elevator pushrod housings Gold-N-Rod #507 Attach hous ings right side 3 using baking soda Hot Stuff Make up pushrod cable-end-fitting Z-clips using soft wiresuch paper clipsof proper diameter fit holes servo arms Cut pieces copper tubing 5/16-in long Gold-N-Rod solder Z-clips forward end pushrod cables solder aft end fittings until final assembly Now excellent time test direction servo rotation pushrod travel sure rudder elevator move proper direction usually get wrong least control time Kraft System use dot servo rudder control install behind wing bolt because receiver has pigtail aileron connector negates possible need servo cable extender elevator servo standard no dot complete fuselage half-shell add 3/32 sq balsa strips F3 left right fuselage sides between wing tail Trial-fit soda straw cocktail straw fuselage serve antenna conduit Bevel aft end side tail post Glue left fuselage side place directly over right side except tail post using modeling clamps hold square Glue fuselage bottom F8 bring sides together tail post bottom fits between sides serves align entire fuselage straight true Install antenna conduit using Hot Stuff Continued page 102 ALL parts cut shape 0 Unique wing construction eliminates dihedral braces wing sheeting DesIgned Iron-on coverings Bottom view rear end shows rudder pushrod cable end fitting rudder notched passage elevator spar receiver antenna exiting soda-straw conduit 1/16 ply rudder horn l3WC QLD THE NEW FIREBALL GLOW PLUGS ARE LEAKPROOF AND BLOWOUT PROOF EVEN FOR THE NEW MONSTER ENGINES BUT THEY ARE STILL THE OLD PRICE OF $110 WRITE NOW! SWANSON P0 Box 151 Wayne NJ 07470 L 98 Model Aviation WINDSOR PROPELLER CO PO Box 112 Windsor CA 95492 Winning Ideas FOURMOST FUEL MANIFOLD o ww o 0 114FUEL SHUT OFFSma Fue Pitting Set Manifold Provides ConvenientCan Used Control Fuel zeI 0PRICE $1 50 Method Tank Filling Draining endFlow Starting1 Tee 2 Elbows 1 Pen Blsdder Tee PrimingPositive Airborn Shutoff % IDPRICE $125PRICE $420 ANDS 00STRUT PAIRINGS Comes two - 23 Lengths cock A- -Th COamingTwo Sizes% 10 s geFue F gS Sze%IDPRCE $200 Packaged 2 Ft Size E ee 1E bowU P g PRICE $250 ngths either size $2 70Bo ii Made oe Fu Send SASE Complete Information FOURMOST 4040 24th Ave Forest Grove OR 97116 PRODUCTS Phone 503 357-2732 baking soda few turns sewing thread necessary Add top hatch hold-down F6 wing TE hold-down F 19 fuselage top sheeting Temporarily install wing using nylon bolt align wing square fuselage install trailing edge screw Glue Fl 9 top hatch F20 carve aft edge fit wing upper surface wing place place straightedge fuselage tail-rest check dihedral alignment between wing horizontal tail Remove shape sand nose block sand fuselage corners have building nothing large models will amazed fast small jobs go together Covering luse MonoKote because its strengthto-weight ratio spend little extra time planning executing multi-colored covering scheme have standardized scheme shown photos white metallic-blue tips splash yellow important bottom omit yellow use blue undersides wing tips horizontal stab/elevator gives excellent visibility variety sky conditions Zephyr gets up nearly out-of-sight hurry color contrast lower surfaces helpful keeping view longer arrange ment provides three points reference helps orienting direction flight pitch climb dive attitude Omit covering tail surfaces g1ued Hinge rudder elevator strip MonoKote least wideattached side opposite beveled edge Leave about 1/16-in space between fixed hinged portions allow freedom movement After MonoKote tightened wings attach undercambered ribs Final assembly Install radio switch top hatch way will leave hatch home left fuselage side just ahead wing above receiver made lightweight switch harness using tiny audio slide switch switches suitable power planes since subject intermit tent operation due vibration Leave out charging jack keep connected charger avoid carrying around extra weight Again install wing glue horizontal tail placewhile carefully aligning wing viewed rear Also note slot stab receive fin must centered fuselage aimed straight-away wing bolt Epoxy yes first time have called epoxy rudder elevator horns place Terminate cable pushrod Z-clips first turn radio center trim knobs rudder elevator surfaces must neutral positions solder end-fit tings place flight trim adjustments necessary longer shorter Z-clips can made up necessary correction Operate servos full-travel sure no binding Now make sure center-of-gravity CG balanced per plans get rid warps -in washout tips good Flying Thermal slope hand-launch mini hi-start take pick Initially suggest go over local park baseball diamond grass ouffield Start some gentle tosses adding little muscle build confidence Also start aim little higher soon will tossing up about 60 degrees getting 50 60 feet altitude top climb have best success stiff-arm toss sling getting waist shoulder keeps throwing arm away Its just like tosing hand grenades back WW II After have throwing down can push over top climb stalling walk over downwind edge bare infield baseball field sun hot relative ground wind blowing just might pick up little thermal breeze blowing best circle S-turnsalways turning winduntil get lift turns too tight will create lots wing lift lots drag same time Keep turns shallow practical wing will contribute altitude gain just going around circles always considered desert great place thermals isnt necessarily desert floor just too regnlar uniformthat unless can find place has few ridges barren spots have relatives live desert first visit after finishing prototype Zephyr took along morning hot clear calm couldnt get anything few wing wiggles occasional bump lift spotted little ditch someone dug lay water pipe foot-high ridge bare dirt took start bubble warm air its way up able work small amount lift generated several minutes time tiring work because have put model exactiy right spot time So much hand-launching desert Just kicks made mini hi-start using 25 102 Model Aviation MASIElI AIRSCRIW FLIGHTBOX KIT Master Airscrew Flight Box has features larger boxes compact handy arrangement parts cut imported mahogany plywood will take stain varnish paint finishes overall size 19Wx9Wx 12 high $ dat dealer postpaid California add 6% Sales Tax Propeller storage Gravity closed small parts storage 7/8 aluminum handle Complete instructions & fasteners FEATURES INCLUDE Space battery & meter panel Transmitter compartment Room gallon fuel ft 3/1 6-in flat rubber 100 ft I0-lb-test fishing line old antenna ribbon streamer place usual parachute optional tow hook shown plan worked very well yeilded better results desert hand-launching am sure would better twice length rubber line Maybe am just lazy Slope Soaring much liking especially late lazy afternoons wind down whisper just few Gliders left slopejust barely scratching out flight Zephyr really shines always last plane forced land can tossed up 50 ft above ridge just gentlest breezes will permit several passes problem very well yielded better results desert because youre still flying cant stay out brush down slope ridge Balance very important gentle forgiving little bird slow flight hand-launching speed range quite broad hand-launching easily going 50 mph launch leaves hand about 10 mph light lift can trimmed both conditions Thought would never ask get balance correct place will trimmed both conditions anything between throw up should go straight rock zooms up have too nose-heavy thats right nose-heavy too tail-heavy will tend arc downward slight dive both cases assumes have model adjusted relatively slow hands-off glide Without getting lengthy aerodynamic discussion extra nose weight causes extra up-elevator trim just keep model level during slow flight throw hard above trim speed up-elevator trim causes nose pull up can also test same thing gliding higher up Start slow-trimmed glide Gradually push nose down hold control stick same position model builds up speed tends pull out dive too nose-heavy dive steepens tail-heavy correct balance should continue same diving attitude started correct balance point Zephyr will loops rolls inverted flight dont expect inverted flight undercambered airfoil good upright flight decent wind slope should able maintain altitude inverted have Zephyr mastered make control surfaces sensitive travel better real fun Radio Technique/Myers Continued page 23 reason judge end-of-charge point voltage small part battery voltage lost across ammeter larger part lost inside battery batteries have internal resistance new AA-size nickle-cadmium battery will show about 035 ohms operating about 75% full charge As charge exhausted resistance increases until reaches about 100 ohms battery shows terminal voltage around 10 VDC numbers look small until consider multiply four get pack resistance add some ohms account welded tabs soldered joints wire plug Figure flight pack will vary depending its state charge Multiply resistance current Continued page 106 May1981 103 Shes surprisingly easy handle. can really get up go. WING SPAN 56 rfster LENGTH 39 WEIGHT 5-6 LBS POWER 40 C0VERITE 420 BABYLON RD 1-IORSHAM PA 19044
Edition: Model Aviation - 1981/05
Page Numbers: 16, 17, 18, 19, 20, 98, 102, 103
NO OCR TEXT NO OCR TEXT Author-designer-builder Bob Owens poses prior start local Sailplane Contest standard models Note slender fuselage generous tail moment arm Airfoil undercambered Eppler 387 Hard balsa plywood speci fied experience has told wasnt quite strong enough Avoid use epoxy doesnt evaporate reduce weight Instead use aliphatic resin thinned about 30% water Use sparing ly double-glue high-stress areas suggest make apolicator small squeeze-bottle such Zaptpflon tube can layof glue get ti tail surfaces 54it wood except SI S4 balsa Resist temptatior substituting larger yr really much nree arneren versions Zephyr view Headed straight us first conventional tapered wing Number 2 subject article Red Job heavyweight 13 oz imagined Anyway repairs quickly easilybeen covered 280-grit wet-or-dry sandpaper Follow plans least first oneattached Supertape sandpaper holds place cutting straight edges sheet balsa Preplanniag Before starting construction layand cutting strip wood out radio plansboth side bottom viewsto assure will fit Compare theConstruction suggest getting dull w width index finger sure will fit inof way enthusiasm ri finger notch may wish adjust theyou havent built Peanut Sc fuselage size less depending thelately now time get inL width radio finger Now time tobuilding light Use new No 11 make decision little ii ace foron soft wood get clean cut foam padding around receiver ry soit isnt anything unusui better leave plastsurfaces except fin ar Make upakitofparts Youvedge LE kept ng long straight cut uscovering Bevel aluminum has truepermit least 30 14EY PW NJOThEP Rs OSF~RII 3/32X 1/4 BALSA 3/8DIA LJ3-ITENING HOLES/IFOR ALL FlN-RUER FRAMES 3/32X V2 SHEET13/32 SQ BRACES FIN BRACES /32 SHEET BALSALEADINGEOGE SPANS CENTER 10P BOTTOM C CENTER SECTION I/32PLYflO CENTER DIHEDRAL BRACENO4 3/B SCREW3/32X /4 HARD BALSA SFR I/4 20 NYLON BOLT THRU BALSA BLOCK HOLD DOWN OVER V32PLW FORNER I/16X /4 HARD BALSA SPARS TOP/BOTTOM VBX I/2SHEET BALSA TRAIUNG EDGE AND TIP 1/32 PLOD1/4 BALSA SERVO BLOCKSI/64PLtwOo FUSELAGEI/B X 1/4 BALSA1/32 PLYWCO BRACE1/32 SHEET BALSA CWERS DOUBLER AT GRIP AREALEADING EDGESSPANS TIP DIHEDRALLEADING EDGE TOP AM BOTTOM SOLID NOSE BLOCKI/BX T/8BOTTOM FIlL LENGTHCUT OUT BOTTOM FOR INDEX FINGER FULL-SIZE PLANS AVAILABLE. SEE PAGE 132 5/52 SPAR-WOWOW-- W7 -.- . n-r4 _____ BALSAWRAWH VERTICAlwir SOWIWASPARSWEBN IA ROLE 2W2WZWI_WI N10 01/2 TE STOCK WAILD WWA SAME AS IOil{jREj~1FLAT NOTTOW ERCEPT sSTICK WONOKOTE TO IoTo L~7iWAJV~ALATTEACH OW AFTER SHBIMKNW IIWREORAL BRACES S-~1/52 NOTES ALL RALSA PARTS CONTEST GRADE SOFT ERCEPT WINO & ELED SPARS SI & OH ARE WARS FOR H 2 BALANCE LEVEL AT WING BOLT J FD FBNO205W SCREW WOOWED PAPER CUP OPTORAL TOW HOOK WN OWEN 0 BA ENDEO-N-BOOSSALUGAN NO SOi1 WADDER ELEG HOIRN I/IN PLO/bITS 3/02 ITjRECEIDER OoER%\At FI4JF5Nj~j7-TB I/HF I/NO PlO DOSBIERFA FUSE SIDES 5/52FID FIN ssoBONOGOTE GINHES TI5/FI SERVO WLOCKS FINOER WESTISOTUNRO WEIIDATLIWED OT NO CONDAIT I/A S D/W ANOER NDTH-COTaIT FBI SODA STRAW IWING SPAN021K AFTER FOSE ISAOGEBWAKDP WA WOLEIRI FFR FASE BOTTOM 12WWINOAREA330 ODIN FFRAIOATLINED 851WEIGAT LASS WADE 5 00 AIRFOIL EPPLER 5W FWI/R_____________ IOI-I/HSI-5/ARRLGANDOERLDCK5/SD O5FANFIILFSFN SOAWLERSz 1/52 PLY CUTWWGT EDDESIGNED ADRAWNWT WOW OWENS TO FIT F direction elevator similarily beveled Wing Pin down lower spar wing outer rib dihedral break Add vertical least same travel Notch rudder panel blocking up 1/32-in allow shear webbing dihedral brace Finish off elevator accept control horns Leave sheeting later LE also blocked up adding top spar Wet spar last rib tail structure pinned-down ample time height ribs Pin down trailing edge TE facilitate bending down tip glue set up hard tip glue ribs place except omit Continued page 98 20 Model Aviation WITfl ama DU155 spars EflO one-piece wing strongthanks shear webs fully sheeted leading edge forms rigid structural box Tail surfaces fragile adequate ..hors completed framework ready cover weIghed 3 02 wIthout radio Careful weight control needed prevent climbing 502 Use thinned aliphatic resin sparingly pre-sand balsa parts Author refers fuselage building half-shell Kraft KPS 18 servos built mounted screws permit easy removal Note routing control rods antenna conduit Theres ample space 6-ch Kraft receiver skinny case 225 mAh batterywith case bantamsize servos Fuselage width can bevaried accommodate own radio componentswithin reason FUN SCALE IS ilERE Easier Fly Yet Very Maneuverable Over 20 step-by-step building illustrations easier follow photos Lands Like Trainer Ideal 2nd Trainer Novice 19-25 Engine 19-40 Eng Span 51 Area 490 sq 18-20 oz wing loading 3*-4 lbs Upright Engine Can Built Flown 7 Days Due New Construction Techniques WILL FLY AS SLOW AS PIPER CUB MODEL Write free Catalog JEMCO 1305 Foothill Dr Vista CA 92083 714 724-3242 Zephyr Owens Continued page 20 Build inner wing panels same man ner join outer panel inner panel just before adding top spar Turn plans over build opposite wing Join right left wing halves first adding center dihedral brace add bolt block center rib cut fitted between LE spar between block TE Add LE sheeting following sequence lower inner panels lower outer panels upper inner panels upper outer panels Next add lower center panel upper center panels Sand weigh sand some Since sheeting usually warped edges must trim off slice straightedge mentioned earlierbefore trying glue wing fuselage will built up half shellso speak insufficient space down inside fuselage much work after boxed Everything possible will completed prior installing left side fuselage Attach doublers F7 F9 inside fuselage side F2 Use Hot Stuff Zap Jet make left right side Throughout instructions will refer Hot Stuff can take pick of cyanoacrylate glues Lay right side over side view plans glue place nose block Fl formers F3 F4A F4B F5 fuselage tapers between F3 FS width cross members must carefully measured achieve good fit left side put place Before gluing parts place lay straightedge across F3 F4 F4 F5to sure have good fit Add servo mounting blocks F14 F15 F16 F17 spaced according specific servos Again test fit using straightedge prefer servo tape can omit blocks Add parts make up cavity finger notch Fli F12 F13 Install servos add rudder elevator pushrod housings Gold-N-Rod #507 Attach hous ings right side 3 using baking soda Hot Stuff Make up pushrod cable-end-fitting Z-clips using soft wiresuch paper clipsof proper diameter fit holes servo arms Cut pieces copper tubing 5/16-in long Gold-N-Rod solder Z-clips forward end pushrod cables solder aft end fittings until final assembly Now excellent time test direction servo rotation pushrod travel sure rudder elevator move proper direction usually get wrong least control time Kraft System use dot servo rudder control install behind wing bolt because receiver has pigtail aileron connector negates possible need servo cable extender elevator servo standard no dot complete fuselage half-shell add 3/32 sq balsa strips F3 left right fuselage sides between wing tail Trial-fit soda straw cocktail straw fuselage serve antenna conduit Bevel aft end side tail post Glue left fuselage side place directly over right side except tail post using modeling clamps hold square Glue fuselage bottom F8 bring sides together tail post bottom fits between sides serves align entire fuselage straight true Install antenna conduit using Hot Stuff Continued page 102 ALL parts cut shape 0 Unique wing construction eliminates dihedral braces wing sheeting DesIgned Iron-on coverings Bottom view rear end shows rudder pushrod cable end fitting rudder notched passage elevator spar receiver antenna exiting soda-straw conduit 1/16 ply rudder horn l3WC QLD THE NEW FIREBALL GLOW PLUGS ARE LEAKPROOF AND BLOWOUT PROOF EVEN FOR THE NEW MONSTER ENGINES BUT THEY ARE STILL THE OLD PRICE OF $110 WRITE NOW! SWANSON P0 Box 151 Wayne NJ 07470 L 98 Model Aviation WINDSOR PROPELLER CO PO Box 112 Windsor CA 95492 Winning Ideas FOURMOST FUEL MANIFOLD o ww o 0 114FUEL SHUT OFFSma Fue Pitting Set Manifold Provides ConvenientCan Used Control Fuel zeI 0PRICE $1 50 Method Tank Filling Draining endFlow Starting1 Tee 2 Elbows 1 Pen Blsdder Tee PrimingPositive Airborn Shutoff % IDPRICE $125PRICE $420 ANDS 00STRUT PAIRINGS Comes two - 23 Lengths cock A- -Th COamingTwo Sizes% 10 s geFue F gS Sze%IDPRCE $200 Packaged 2 Ft Size E ee 1E bowU P g PRICE $250 ngths either size $2 70Bo ii Made oe Fu Send SASE Complete Information FOURMOST 4040 24th Ave Forest Grove OR 97116 PRODUCTS Phone 503 357-2732 baking soda few turns sewing thread necessary Add top hatch hold-down F6 wing TE hold-down F 19 fuselage top sheeting Temporarily install wing using nylon bolt align wing square fuselage install trailing edge screw Glue Fl 9 top hatch F20 carve aft edge fit wing upper surface wing place place straightedge fuselage tail-rest check dihedral alignment between wing horizontal tail Remove shape sand nose block sand fuselage corners have building nothing large models will amazed fast small jobs go together Covering luse MonoKote because its strengthto-weight ratio spend little extra time planning executing multi-colored covering scheme have standardized scheme shown photos white metallic-blue tips splash yellow important bottom omit yellow use blue undersides wing tips horizontal stab/elevator gives excellent visibility variety sky conditions Zephyr gets up nearly out-of-sight hurry color contrast lower surfaces helpful keeping view longer arrange ment provides three points reference helps orienting direction flight pitch climb dive attitude Omit covering tail surfaces g1ued Hinge rudder elevator strip MonoKote least wideattached side opposite beveled edge Leave about 1/16-in space between fixed hinged portions allow freedom movement After MonoKote tightened wings attach undercambered ribs Final assembly Install radio switch top hatch way will leave hatch home left fuselage side just ahead wing above receiver made lightweight switch harness using tiny audio slide switch switches suitable power planes since subject intermit tent operation due vibration Leave out charging jack keep connected charger avoid carrying around extra weight Again install wing glue horizontal tail placewhile carefully aligning wing viewed rear Also note slot stab receive fin must centered fuselage aimed straight-away wing bolt Epoxy yes first time have called epoxy rudder elevator horns place Terminate cable pushrod Z-clips first turn radio center trim knobs rudder elevator surfaces must neutral positions solder end-fit tings place flight trim adjustments necessary longer shorter Z-clips can made up necessary correction Operate servos full-travel sure no binding Now make sure center-of-gravity CG balanced per plans get rid warps -in washout tips good Flying Thermal slope hand-launch mini hi-start take pick Initially suggest go over local park baseball diamond grass ouffield Start some gentle tosses adding little muscle build confidence Also start aim little higher soon will tossing up about 60 degrees getting 50 60 feet altitude top climb have best success stiff-arm toss sling getting waist shoulder keeps throwing arm away Its just like tosing hand grenades back WW II After have throwing down can push over top climb stalling walk over downwind edge bare infield baseball field sun hot relative ground wind blowing just might pick up little thermal breeze blowing best circle S-turnsalways turning winduntil get lift turns too tight will create lots wing lift lots drag same time Keep turns shallow practical wing will contribute altitude gain just going around circles always considered desert great place thermals isnt necessarily desert floor just too regnlar uniformthat unless can find place has few ridges barren spots have relatives live desert first visit after finishing prototype Zephyr took along morning hot clear calm couldnt get anything few wing wiggles occasional bump lift spotted little ditch someone dug lay water pipe foot-high ridge bare dirt took start bubble warm air its way up able work small amount lift generated several minutes time tiring work because have put model exactiy right spot time So much hand-launching desert Just kicks made mini hi-start using 25 102 Model Aviation MASIElI AIRSCRIW FLIGHTBOX KIT Master Airscrew Flight Box has features larger boxes compact handy arrangement parts cut imported mahogany plywood will take stain varnish paint finishes overall size 19Wx9Wx 12 high $ dat dealer postpaid California add 6% Sales Tax Propeller storage Gravity closed small parts storage 7/8 aluminum handle Complete instructions & fasteners FEATURES INCLUDE Space battery & meter panel Transmitter compartment Room gallon fuel ft 3/1 6-in flat rubber 100 ft I0-lb-test fishing line old antenna ribbon streamer place usual parachute optional tow hook shown plan worked very well yeilded better results desert hand-launching am sure would better twice length rubber line Maybe am just lazy Slope Soaring much liking especially late lazy afternoons wind down whisper just few Gliders left slopejust barely scratching out flight Zephyr really shines always last plane forced land can tossed up 50 ft above ridge just gentlest breezes will permit several passes problem very well yielded better results desert because youre still flying cant stay out brush down slope ridge Balance very important gentle forgiving little bird slow flight hand-launching speed range quite broad hand-launching easily going 50 mph launch leaves hand about 10 mph light lift can trimmed both conditions Thought would never ask get balance correct place will trimmed both conditions anything between throw up should go straight rock zooms up have too nose-heavy thats right nose-heavy too tail-heavy will tend arc downward slight dive both cases assumes have model adjusted relatively slow hands-off glide Without getting lengthy aerodynamic discussion extra nose weight causes extra up-elevator trim just keep model level during slow flight throw hard above trim speed up-elevator trim causes nose pull up can also test same thing gliding higher up Start slow-trimmed glide Gradually push nose down hold control stick same position model builds up speed tends pull out dive too nose-heavy dive steepens tail-heavy correct balance should continue same diving attitude started correct balance point Zephyr will loops rolls inverted flight dont expect inverted flight undercambered airfoil good upright flight decent wind slope should able maintain altitude inverted have Zephyr mastered make control surfaces sensitive travel better real fun Radio Technique/Myers Continued page 23 reason judge end-of-charge point voltage small part battery voltage lost across ammeter larger part lost inside battery batteries have internal resistance new AA-size nickle-cadmium battery will show about 035 ohms operating about 75% full charge As charge exhausted resistance increases until reaches about 100 ohms battery shows terminal voltage around 10 VDC numbers look small until consider multiply four get pack resistance add some ohms account welded tabs soldered joints wire plug Figure flight pack will vary depending its state charge Multiply resistance current Continued page 106 May1981 103 Shes surprisingly easy handle. can really get up go. WING SPAN 56 rfster LENGTH 39 WEIGHT 5-6 LBS POWER 40 C0VERITE 420 BABYLON RD 1-IORSHAM PA 19044
Edition: Model Aviation - 1981/05
Page Numbers: 16, 17, 18, 19, 20, 98, 102, 103
NO OCR TEXT NO OCR TEXT Author-designer-builder Bob Owens poses prior start local Sailplane Contest standard models Note slender fuselage generous tail moment arm Airfoil undercambered Eppler 387 Hard balsa plywood speci fied experience has told wasnt quite strong enough Avoid use epoxy doesnt evaporate reduce weight Instead use aliphatic resin thinned about 30% water Use sparing ly double-glue high-stress areas suggest make apolicator small squeeze-bottle such Zaptpflon tube can layof glue get ti tail surfaces 54it wood except SI S4 balsa Resist temptatior substituting larger yr really much nree arneren versions Zephyr view Headed straight us first conventional tapered wing Number 2 subject article Red Job heavyweight 13 oz imagined Anyway repairs quickly easilybeen covered 280-grit wet-or-dry sandpaper Follow plans least first oneattached Supertape sandpaper holds place cutting straight edges sheet balsa Preplanniag Before starting construction layand cutting strip wood out radio plansboth side bottom viewsto assure will fit Compare theConstruction suggest getting dull w width index finger sure will fit inof way enthusiasm ri finger notch may wish adjust theyou havent built Peanut Sc fuselage size less depending thelately now time get inL width radio finger Now time tobuilding light Use new No 11 make decision little ii ace foron soft wood get clean cut foam padding around receiver ry soit isnt anything unusui better leave plastsurfaces except fin ar Make upakitofparts Youvedge LE kept ng long straight cut uscovering Bevel aluminum has truepermit least 30 14EY PW NJOThEP Rs OSF~RII 3/32X 1/4 BALSA 3/8DIA LJ3-ITENING HOLES/IFOR ALL FlN-RUER FRAMES 3/32X V2 SHEET13/32 SQ BRACES FIN BRACES /32 SHEET BALSALEADINGEOGE SPANS CENTER 10P BOTTOM C CENTER SECTION I/32PLYflO CENTER DIHEDRAL BRACENO4 3/B SCREW3/32X /4 HARD BALSA SFR I/4 20 NYLON BOLT THRU BALSA BLOCK HOLD DOWN OVER V32PLW FORNER I/16X /4 HARD BALSA SPARS TOP/BOTTOM VBX I/2SHEET BALSA TRAIUNG EDGE AND TIP 1/32 PLOD1/4 BALSA SERVO BLOCKSI/64PLtwOo FUSELAGEI/B X 1/4 BALSA1/32 PLYWCO BRACE1/32 SHEET BALSA CWERS DOUBLER AT GRIP AREALEADING EDGESSPANS TIP DIHEDRALLEADING EDGE TOP AM BOTTOM SOLID NOSE BLOCKI/BX T/8BOTTOM FIlL LENGTHCUT OUT BOTTOM FOR INDEX FINGER FULL-SIZE PLANS AVAILABLE. SEE PAGE 132 5/52 SPAR-WOWOW-- W7 -.- . n-r4 _____ BALSAWRAWH VERTICAlwir SOWIWASPARSWEBN IA ROLE 2W2WZWI_WI N10 01/2 TE STOCK WAILD WWA SAME AS IOil{jREj~1FLAT NOTTOW ERCEPT sSTICK WONOKOTE TO IoTo L~7iWAJV~ALATTEACH OW AFTER SHBIMKNW IIWREORAL BRACES S-~1/52 NOTES ALL RALSA PARTS CONTEST GRADE SOFT ERCEPT WINO & ELED SPARS SI & OH ARE WARS FOR H 2 BALANCE LEVEL AT WING BOLT J FD FBNO205W SCREW WOOWED PAPER CUP OPTORAL TOW HOOK WN OWEN 0 BA ENDEO-N-BOOSSALUGAN NO SOi1 WADDER ELEG HOIRN I/IN PLO/bITS 3/02 ITjRECEIDER OoER%\At FI4JF5Nj~j7-TB I/HF I/NO PlO DOSBIERFA FUSE SIDES 5/52FID FIN ssoBONOGOTE GINHES TI5/FI SERVO WLOCKS FINOER WESTISOTUNRO WEIIDATLIWED OT NO CONDAIT I/A S D/W ANOER NDTH-COTaIT FBI SODA STRAW IWING SPAN021K AFTER FOSE ISAOGEBWAKDP WA WOLEIRI FFR FASE BOTTOM 12WWINOAREA330 ODIN FFRAIOATLINED 851WEIGAT LASS WADE 5 00 AIRFOIL EPPLER 5W FWI/R_____________ IOI-I/HSI-5/ARRLGANDOERLDCK5/SD O5FANFIILFSFN SOAWLERSz 1/52 PLY CUTWWGT EDDESIGNED ADRAWNWT WOW OWENS TO FIT F direction elevator similarily beveled Wing Pin down lower spar wing outer rib dihedral break Add vertical least same travel Notch rudder panel blocking up 1/32-in allow shear webbing dihedral brace Finish off elevator accept control horns Leave sheeting later LE also blocked up adding top spar Wet spar last rib tail structure pinned-down ample time height ribs Pin down trailing edge TE facilitate bending down tip glue set up hard tip glue ribs place except omit Continued page 98 20 Model Aviation WITfl ama DU155 spars EflO one-piece wing strongthanks shear webs fully sheeted leading edge forms rigid structural box Tail surfaces fragile adequate ..hors completed framework ready cover weIghed 3 02 wIthout radio Careful weight control needed prevent climbing 502 Use thinned aliphatic resin sparingly pre-sand balsa parts Author refers fuselage building half-shell Kraft KPS 18 servos built mounted screws permit easy removal Note routing control rods antenna conduit Theres ample space 6-ch Kraft receiver skinny case 225 mAh batterywith case bantamsize servos Fuselage width can bevaried accommodate own radio componentswithin reason FUN SCALE IS ilERE Easier Fly Yet Very Maneuverable Over 20 step-by-step building illustrations easier follow photos Lands Like Trainer Ideal 2nd Trainer Novice 19-25 Engine 19-40 Eng Span 51 Area 490 sq 18-20 oz wing loading 3*-4 lbs Upright Engine Can Built Flown 7 Days Due New Construction Techniques WILL FLY AS SLOW AS PIPER CUB MODEL Write free Catalog JEMCO 1305 Foothill Dr Vista CA 92083 714 724-3242 Zephyr Owens Continued page 20 Build inner wing panels same man ner join outer panel inner panel just before adding top spar Turn plans over build opposite wing Join right left wing halves first adding center dihedral brace add bolt block center rib cut fitted between LE spar between block TE Add LE sheeting following sequence lower inner panels lower outer panels upper inner panels upper outer panels Next add lower center panel upper center panels Sand weigh sand some Since sheeting usually warped edges must trim off slice straightedge mentioned earlierbefore trying glue wing fuselage will built up half shellso speak insufficient space down inside fuselage much work after boxed Everything possible will completed prior installing left side fuselage Attach doublers F7 F9 inside fuselage side F2 Use Hot Stuff Zap Jet make left right side Throughout instructions will refer Hot Stuff can take pick of cyanoacrylate glues Lay right side over side view plans glue place nose block Fl formers F3 F4A F4B F5 fuselage tapers between F3 FS width cross members must carefully measured achieve good fit left side put place Before gluing parts place lay straightedge across F3 F4 F4 F5to sure have good fit Add servo mounting blocks F14 F15 F16 F17 spaced according specific servos Again test fit using straightedge prefer servo tape can omit blocks Add parts make up cavity finger notch Fli F12 F13 Install servos add rudder elevator pushrod housings Gold-N-Rod #507 Attach hous ings right side 3 using baking soda Hot Stuff Make up pushrod cable-end-fitting Z-clips using soft wiresuch paper clipsof proper diameter fit holes servo arms Cut pieces copper tubing 5/16-in long Gold-N-Rod solder Z-clips forward end pushrod cables solder aft end fittings until final assembly Now excellent time test direction servo rotation pushrod travel sure rudder elevator move proper direction usually get wrong least control time Kraft System use dot servo rudder control install behind wing bolt because receiver has pigtail aileron connector negates possible need servo cable extender elevator servo standard no dot complete fuselage half-shell add 3/32 sq balsa strips F3 left right fuselage sides between wing tail Trial-fit soda straw cocktail straw fuselage serve antenna conduit Bevel aft end side tail post Glue left fuselage side place directly over right side except tail post using modeling clamps hold square Glue fuselage bottom F8 bring sides together tail post bottom fits between sides serves align entire fuselage straight true Install antenna conduit using Hot Stuff Continued page 102 ALL parts cut shape 0 Unique wing construction eliminates dihedral braces wing sheeting DesIgned Iron-on coverings Bottom view rear end shows rudder pushrod cable end fitting rudder notched passage elevator spar receiver antenna exiting soda-straw conduit 1/16 ply rudder horn l3WC QLD THE NEW FIREBALL GLOW PLUGS ARE LEAKPROOF AND BLOWOUT PROOF EVEN FOR THE NEW MONSTER ENGINES BUT THEY ARE STILL THE OLD PRICE OF $110 WRITE NOW! SWANSON P0 Box 151 Wayne NJ 07470 L 98 Model Aviation WINDSOR PROPELLER CO PO Box 112 Windsor CA 95492 Winning Ideas FOURMOST FUEL MANIFOLD o ww o 0 114FUEL SHUT OFFSma Fue Pitting Set Manifold Provides ConvenientCan Used Control Fuel zeI 0PRICE $1 50 Method Tank Filling Draining endFlow Starting1 Tee 2 Elbows 1 Pen Blsdder Tee PrimingPositive Airborn Shutoff % IDPRICE $125PRICE $420 ANDS 00STRUT PAIRINGS Comes two - 23 Lengths cock A- -Th COamingTwo Sizes% 10 s geFue F gS Sze%IDPRCE $200 Packaged 2 Ft Size E ee 1E bowU P g PRICE $250 ngths either size $2 70Bo ii Made oe Fu Send SASE Complete Information FOURMOST 4040 24th Ave Forest Grove OR 97116 PRODUCTS Phone 503 357-2732 baking soda few turns sewing thread necessary Add top hatch hold-down F6 wing TE hold-down F 19 fuselage top sheeting Temporarily install wing using nylon bolt align wing square fuselage install trailing edge screw Glue Fl 9 top hatch F20 carve aft edge fit wing upper surface wing place place straightedge fuselage tail-rest check dihedral alignment between wing horizontal tail Remove shape sand nose block sand fuselage corners have building nothing large models will amazed fast small jobs go together Covering luse MonoKote because its strengthto-weight ratio spend little extra time planning executing multi-colored covering scheme have standardized scheme shown photos white metallic-blue tips splash yellow important bottom omit yellow use blue undersides wing tips horizontal stab/elevator gives excellent visibility variety sky conditions Zephyr gets up nearly out-of-sight hurry color contrast lower surfaces helpful keeping view longer arrange ment provides three points reference helps orienting direction flight pitch climb dive attitude Omit covering tail surfaces g1ued Hinge rudder elevator strip MonoKote least wideattached side opposite beveled edge Leave about 1/16-in space between fixed hinged portions allow freedom movement After MonoKote tightened wings attach undercambered ribs Final assembly Install radio switch top hatch way will leave hatch home left fuselage side just ahead wing above receiver made lightweight switch harness using tiny audio slide switch switches suitable power planes since subject intermit tent operation due vibration Leave out charging jack keep connected charger avoid carrying around extra weight Again install wing glue horizontal tail placewhile carefully aligning wing viewed rear Also note slot stab receive fin must centered fuselage aimed straight-away wing bolt Epoxy yes first time have called epoxy rudder elevator horns place Terminate cable pushrod Z-clips first turn radio center trim knobs rudder elevator surfaces must neutral positions solder end-fit tings place flight trim adjustments necessary longer shorter Z-clips can made up necessary correction Operate servos full-travel sure no binding Now make sure center-of-gravity CG balanced per plans get rid warps -in washout tips good Flying Thermal slope hand-launch mini hi-start take pick Initially suggest go over local park baseball diamond grass ouffield Start some gentle tosses adding little muscle build confidence Also start aim little higher soon will tossing up about 60 degrees getting 50 60 feet altitude top climb have best success stiff-arm toss sling getting waist shoulder keeps throwing arm away Its just like tosing hand grenades back WW II After have throwing down can push over top climb stalling walk over downwind edge bare infield baseball field sun hot relative ground wind blowing just might pick up little thermal breeze blowing best circle S-turnsalways turning winduntil get lift turns too tight will create lots wing lift lots drag same time Keep turns shallow practical wing will contribute altitude gain just going around circles always considered desert great place thermals isnt necessarily desert floor just too regnlar uniformthat unless can find place has few ridges barren spots have relatives live desert first visit after finishing prototype Zephyr took along morning hot clear calm couldnt get anything few wing wiggles occasional bump lift spotted little ditch someone dug lay water pipe foot-high ridge bare dirt took start bubble warm air its way up able work small amount lift generated several minutes time tiring work because have put model exactiy right spot time So much hand-launching desert Just kicks made mini hi-start using 25 102 Model Aviation MASIElI AIRSCRIW FLIGHTBOX KIT Master Airscrew Flight Box has features larger boxes compact handy arrangement parts cut imported mahogany plywood will take stain varnish paint finishes overall size 19Wx9Wx 12 high $ dat dealer postpaid California add 6% Sales Tax Propeller storage Gravity closed small parts storage 7/8 aluminum handle Complete instructions & fasteners FEATURES INCLUDE Space battery & meter panel Transmitter compartment Room gallon fuel ft 3/1 6-in flat rubber 100 ft I0-lb-test fishing line old antenna ribbon streamer place usual parachute optional tow hook shown plan worked very well yeilded better results desert hand-launching am sure would better twice length rubber line Maybe am just lazy Slope Soaring much liking especially late lazy afternoons wind down whisper just few Gliders left slopejust barely scratching out flight Zephyr really shines always last plane forced land can tossed up 50 ft above ridge just gentlest breezes will permit several passes problem very well yielded better results desert because youre still flying cant stay out brush down slope ridge Balance very important gentle forgiving little bird slow flight hand-launching speed range quite broad hand-launching easily going 50 mph launch leaves hand about 10 mph light lift can trimmed both conditions Thought would never ask get balance correct place will trimmed both conditions anything between throw up should go straight rock zooms up have too nose-heavy thats right nose-heavy too tail-heavy will tend arc downward slight dive both cases assumes have model adjusted relatively slow hands-off glide Without getting lengthy aerodynamic discussion extra nose weight causes extra up-elevator trim just keep model level during slow flight throw hard above trim speed up-elevator trim causes nose pull up can also test same thing gliding higher up Start slow-trimmed glide Gradually push nose down hold control stick same position model builds up speed tends pull out dive too nose-heavy dive steepens tail-heavy correct balance should continue same diving attitude started correct balance point Zephyr will loops rolls inverted flight dont expect inverted flight undercambered airfoil good upright flight decent wind slope should able maintain altitude inverted have Zephyr mastered make control surfaces sensitive travel better real fun Radio Technique/Myers Continued page 23 reason judge end-of-charge point voltage small part battery voltage lost across ammeter larger part lost inside battery batteries have internal resistance new AA-size nickle-cadmium battery will show about 035 ohms operating about 75% full charge As charge exhausted resistance increases until reaches about 100 ohms battery shows terminal voltage around 10 VDC numbers look small until consider multiply four get pack resistance add some ohms account welded tabs soldered joints wire plug Figure flight pack will vary depending its state charge Multiply resistance current Continued page 106 May1981 103 Shes surprisingly easy handle. can really get up go. WING SPAN 56 rfster LENGTH 39 WEIGHT 5-6 LBS POWER 40 C0VERITE 420 BABYLON RD 1-IORSHAM PA 19044
Edition: Model Aviation - 1981/05
Page Numbers: 16, 17, 18, 19, 20, 98, 102, 103
NO OCR TEXT NO OCR TEXT Author-designer-builder Bob Owens poses prior start local Sailplane Contest standard models Note slender fuselage generous tail moment arm Airfoil undercambered Eppler 387 Hard balsa plywood speci fied experience has told wasnt quite strong enough Avoid use epoxy doesnt evaporate reduce weight Instead use aliphatic resin thinned about 30% water Use sparing ly double-glue high-stress areas suggest make apolicator small squeeze-bottle such Zaptpflon tube can layof glue get ti tail surfaces 54it wood except SI S4 balsa Resist temptatior substituting larger yr really much nree arneren versions Zephyr view Headed straight us first conventional tapered wing Number 2 subject article Red Job heavyweight 13 oz imagined Anyway repairs quickly easilybeen covered 280-grit wet-or-dry sandpaper Follow plans least first oneattached Supertape sandpaper holds place cutting straight edges sheet balsa Preplanniag Before starting construction layand cutting strip wood out radio plansboth side bottom viewsto assure will fit Compare theConstruction suggest getting dull w width index finger sure will fit inof way enthusiasm ri finger notch may wish adjust theyou havent built Peanut Sc fuselage size less depending thelately now time get inL width radio finger Now time tobuilding light Use new No 11 make decision little ii ace foron soft wood get clean cut foam padding around receiver ry soit isnt anything unusui better leave plastsurfaces except fin ar Make upakitofparts Youvedge LE kept ng long straight cut uscovering Bevel aluminum has truepermit least 30 14EY PW NJOThEP Rs OSF~RII 3/32X 1/4 BALSA 3/8DIA LJ3-ITENING HOLES/IFOR ALL FlN-RUER FRAMES 3/32X V2 SHEET13/32 SQ BRACES FIN BRACES /32 SHEET BALSALEADINGEOGE SPANS CENTER 10P BOTTOM C CENTER SECTION I/32PLYflO CENTER DIHEDRAL BRACENO4 3/B SCREW3/32X /4 HARD BALSA SFR I/4 20 NYLON BOLT THRU BALSA BLOCK HOLD DOWN OVER V32PLW FORNER I/16X /4 HARD BALSA SPARS TOP/BOTTOM VBX I/2SHEET BALSA TRAIUNG EDGE AND TIP 1/32 PLOD1/4 BALSA SERVO BLOCKSI/64PLtwOo FUSELAGEI/B X 1/4 BALSA1/32 PLYWCO BRACE1/32 SHEET BALSA CWERS DOUBLER AT GRIP AREALEADING EDGESSPANS TIP DIHEDRALLEADING EDGE TOP AM BOTTOM SOLID NOSE BLOCKI/BX T/8BOTTOM FIlL LENGTHCUT OUT BOTTOM FOR INDEX FINGER FULL-SIZE PLANS AVAILABLE. SEE PAGE 132 5/52 SPAR-WOWOW-- W7 -.- . n-r4 _____ BALSAWRAWH VERTICAlwir SOWIWASPARSWEBN IA ROLE 2W2WZWI_WI N10 01/2 TE STOCK WAILD WWA SAME AS IOil{jREj~1FLAT NOTTOW ERCEPT sSTICK WONOKOTE TO IoTo L~7iWAJV~ALATTEACH OW AFTER SHBIMKNW IIWREORAL BRACES S-~1/52 NOTES ALL RALSA PARTS CONTEST GRADE SOFT ERCEPT WINO & ELED SPARS SI & OH ARE WARS FOR H 2 BALANCE LEVEL AT WING BOLT J FD FBNO205W SCREW WOOWED PAPER CUP OPTORAL TOW HOOK WN OWEN 0 BA ENDEO-N-BOOSSALUGAN NO SOi1 WADDER ELEG HOIRN I/IN PLO/bITS 3/02 ITjRECEIDER OoER%\At FI4JF5Nj~j7-TB I/HF I/NO PlO DOSBIERFA FUSE SIDES 5/52FID FIN ssoBONOGOTE GINHES TI5/FI SERVO WLOCKS FINOER WESTISOTUNRO WEIIDATLIWED OT NO CONDAIT I/A S D/W ANOER NDTH-COTaIT FBI SODA STRAW IWING SPAN021K AFTER FOSE ISAOGEBWAKDP WA WOLEIRI FFR FASE BOTTOM 12WWINOAREA330 ODIN FFRAIOATLINED 851WEIGAT LASS WADE 5 00 AIRFOIL EPPLER 5W FWI/R_____________ IOI-I/HSI-5/ARRLGANDOERLDCK5/SD O5FANFIILFSFN SOAWLERSz 1/52 PLY CUTWWGT EDDESIGNED ADRAWNWT WOW OWENS TO FIT F direction elevator similarily beveled Wing Pin down lower spar wing outer rib dihedral break Add vertical least same travel Notch rudder panel blocking up 1/32-in allow shear webbing dihedral brace Finish off elevator accept control horns Leave sheeting later LE also blocked up adding top spar Wet spar last rib tail structure pinned-down ample time height ribs Pin down trailing edge TE facilitate bending down tip glue set up hard tip glue ribs place except omit Continued page 98 20 Model Aviation WITfl ama DU155 spars EflO one-piece wing strongthanks shear webs fully sheeted leading edge forms rigid structural box Tail surfaces fragile adequate ..hors completed framework ready cover weIghed 3 02 wIthout radio Careful weight control needed prevent climbing 502 Use thinned aliphatic resin sparingly pre-sand balsa parts Author refers fuselage building half-shell Kraft KPS 18 servos built mounted screws permit easy removal Note routing control rods antenna conduit Theres ample space 6-ch Kraft receiver skinny case 225 mAh batterywith case bantamsize servos Fuselage width can bevaried accommodate own radio componentswithin reason FUN SCALE IS ilERE Easier Fly Yet Very Maneuverable Over 20 step-by-step building illustrations easier follow photos Lands Like Trainer Ideal 2nd Trainer Novice 19-25 Engine 19-40 Eng Span 51 Area 490 sq 18-20 oz wing loading 3*-4 lbs Upright Engine Can Built Flown 7 Days Due New Construction Techniques WILL FLY AS SLOW AS PIPER CUB MODEL Write free Catalog JEMCO 1305 Foothill Dr Vista CA 92083 714 724-3242 Zephyr Owens Continued page 20 Build inner wing panels same man ner join outer panel inner panel just before adding top spar Turn plans over build opposite wing Join right left wing halves first adding center dihedral brace add bolt block center rib cut fitted between LE spar between block TE Add LE sheeting following sequence lower inner panels lower outer panels upper inner panels upper outer panels Next add lower center panel upper center panels Sand weigh sand some Since sheeting usually warped edges must trim off slice straightedge mentioned earlierbefore trying glue wing fuselage will built up half shellso speak insufficient space down inside fuselage much work after boxed Everything possible will completed prior installing left side fuselage Attach doublers F7 F9 inside fuselage side F2 Use Hot Stuff Zap Jet make left right side Throughout instructions will refer Hot Stuff can take pick of cyanoacrylate glues Lay right side over side view plans glue place nose block Fl formers F3 F4A F4B F5 fuselage tapers between F3 FS width cross members must carefully measured achieve good fit left side put place Before gluing parts place lay straightedge across F3 F4 F4 F5to sure have good fit Add servo mounting blocks F14 F15 F16 F17 spaced according specific servos Again test fit using straightedge prefer servo tape can omit blocks Add parts make up cavity finger notch Fli F12 F13 Install servos add rudder elevator pushrod housings Gold-N-Rod #507 Attach hous ings right side 3 using baking soda Hot Stuff Make up pushrod cable-end-fitting Z-clips using soft wiresuch paper clipsof proper diameter fit holes servo arms Cut pieces copper tubing 5/16-in long Gold-N-Rod solder Z-clips forward end pushrod cables solder aft end fittings until final assembly Now excellent time test direction servo rotation pushrod travel sure rudder elevator move proper direction usually get wrong least control time Kraft System use dot servo rudder control install behind wing bolt because receiver has pigtail aileron connector negates possible need servo cable extender elevator servo standard no dot complete fuselage half-shell add 3/32 sq balsa strips F3 left right fuselage sides between wing tail Trial-fit soda straw cocktail straw fuselage serve antenna conduit Bevel aft end side tail post Glue left fuselage side place directly over right side except tail post using modeling clamps hold square Glue fuselage bottom F8 bring sides together tail post bottom fits between sides serves align entire fuselage straight true Install antenna conduit using Hot Stuff Continued page 102 ALL parts cut shape 0 Unique wing construction eliminates dihedral braces wing sheeting DesIgned Iron-on coverings Bottom view rear end shows rudder pushrod cable end fitting rudder notched passage elevator spar receiver antenna exiting soda-straw conduit 1/16 ply rudder horn l3WC QLD THE NEW FIREBALL GLOW PLUGS ARE LEAKPROOF AND BLOWOUT PROOF EVEN FOR THE NEW MONSTER ENGINES BUT THEY ARE STILL THE OLD PRICE OF $110 WRITE NOW! SWANSON P0 Box 151 Wayne NJ 07470 L 98 Model Aviation WINDSOR PROPELLER CO PO Box 112 Windsor CA 95492 Winning Ideas FOURMOST FUEL MANIFOLD o ww o 0 114FUEL SHUT OFFSma Fue Pitting Set Manifold Provides ConvenientCan Used Control Fuel zeI 0PRICE $1 50 Method Tank Filling Draining endFlow Starting1 Tee 2 Elbows 1 Pen Blsdder Tee PrimingPositive Airborn Shutoff % IDPRICE $125PRICE $420 ANDS 00STRUT PAIRINGS Comes two - 23 Lengths cock A- -Th COamingTwo Sizes% 10 s geFue F gS Sze%IDPRCE $200 Packaged 2 Ft Size E ee 1E bowU P g PRICE $250 ngths either size $2 70Bo ii Made oe Fu Send SASE Complete Information FOURMOST 4040 24th Ave Forest Grove OR 97116 PRODUCTS Phone 503 357-2732 baking soda few turns sewing thread necessary Add top hatch hold-down F6 wing TE hold-down F 19 fuselage top sheeting Temporarily install wing using nylon bolt align wing square fuselage install trailing edge screw Glue Fl 9 top hatch F20 carve aft edge fit wing upper surface wing place place straightedge fuselage tail-rest check dihedral alignment between wing horizontal tail Remove shape sand nose block sand fuselage corners have building nothing large models will amazed fast small jobs go together Covering luse MonoKote because its strengthto-weight ratio spend little extra time planning executing multi-colored covering scheme have standardized scheme shown photos white metallic-blue tips splash yellow important bottom omit yellow use blue undersides wing tips horizontal stab/elevator gives excellent visibility variety sky conditions Zephyr gets up nearly out-of-sight hurry color contrast lower surfaces helpful keeping view longer arrange ment provides three points reference helps orienting direction flight pitch climb dive attitude Omit covering tail surfaces g1ued Hinge rudder elevator strip MonoKote least wideattached side opposite beveled edge Leave about 1/16-in space between fixed hinged portions allow freedom movement After MonoKote tightened wings attach undercambered ribs Final assembly Install radio switch top hatch way will leave hatch home left fuselage side just ahead wing above receiver made lightweight switch harness using tiny audio slide switch switches suitable power planes since subject intermit tent operation due vibration Leave out charging jack keep connected charger avoid carrying around extra weight Again install wing glue horizontal tail placewhile carefully aligning wing viewed rear Also note slot stab receive fin must centered fuselage aimed straight-away wing bolt Epoxy yes first time have called epoxy rudder elevator horns place Terminate cable pushrod Z-clips first turn radio center trim knobs rudder elevator surfaces must neutral positions solder end-fit tings place flight trim adjustments necessary longer shorter Z-clips can made up necessary correction Operate servos full-travel sure no binding Now make sure center-of-gravity CG balanced per plans get rid warps -in washout tips good Flying Thermal slope hand-launch mini hi-start take pick Initially suggest go over local park baseball diamond grass ouffield Start some gentle tosses adding little muscle build confidence Also start aim little higher soon will tossing up about 60 degrees getting 50 60 feet altitude top climb have best success stiff-arm toss sling getting waist shoulder keeps throwing arm away Its just like tosing hand grenades back WW II After have throwing down can push over top climb stalling walk over downwind edge bare infield baseball field sun hot relative ground wind blowing just might pick up little thermal breeze blowing best circle S-turnsalways turning winduntil get lift turns too tight will create lots wing lift lots drag same time Keep turns shallow practical wing will contribute altitude gain just going around circles always considered desert great place thermals isnt necessarily desert floor just too regnlar uniformthat unless can find place has few ridges barren spots have relatives live desert first visit after finishing prototype Zephyr took along morning hot clear calm couldnt get anything few wing wiggles occasional bump lift spotted little ditch someone dug lay water pipe foot-high ridge bare dirt took start bubble warm air its way up able work small amount lift generated several minutes time tiring work because have put model exactiy right spot time So much hand-launching desert Just kicks made mini hi-start using 25 102 Model Aviation MASIElI AIRSCRIW FLIGHTBOX KIT Master Airscrew Flight Box has features larger boxes compact handy arrangement parts cut imported mahogany plywood will take stain varnish paint finishes overall size 19Wx9Wx 12 high $ dat dealer postpaid California add 6% Sales Tax Propeller storage Gravity closed small parts storage 7/8 aluminum handle Complete instructions & fasteners FEATURES INCLUDE Space battery & meter panel Transmitter compartment Room gallon fuel ft 3/1 6-in flat rubber 100 ft I0-lb-test fishing line old antenna ribbon streamer place usual parachute optional tow hook shown plan worked very well yeilded better results desert hand-launching am sure would better twice length rubber line Maybe am just lazy Slope Soaring much liking especially late lazy afternoons wind down whisper just few Gliders left slopejust barely scratching out flight Zephyr really shines always last plane forced land can tossed up 50 ft above ridge just gentlest breezes will permit several passes problem very well yielded better results desert because youre still flying cant stay out brush down slope ridge Balance very important gentle forgiving little bird slow flight hand-launching speed range quite broad hand-launching easily going 50 mph launch leaves hand about 10 mph light lift can trimmed both conditions Thought would never ask get balance correct place will trimmed both conditions anything between throw up should go straight rock zooms up have too nose-heavy thats right nose-heavy too tail-heavy will tend arc downward slight dive both cases assumes have model adjusted relatively slow hands-off glide Without getting lengthy aerodynamic discussion extra nose weight causes extra up-elevator trim just keep model level during slow flight throw hard above trim speed up-elevator trim causes nose pull up can also test same thing gliding higher up Start slow-trimmed glide Gradually push nose down hold control stick same position model builds up speed tends pull out dive too nose-heavy dive steepens tail-heavy correct balance should continue same diving attitude started correct balance point Zephyr will loops rolls inverted flight dont expect inverted flight undercambered airfoil good upright flight decent wind slope should able maintain altitude inverted have Zephyr mastered make control surfaces sensitive travel better real fun Radio Technique/Myers Continued page 23 reason judge end-of-charge point voltage small part battery voltage lost across ammeter larger part lost inside battery batteries have internal resistance new AA-size nickle-cadmium battery will show about 035 ohms operating about 75% full charge As charge exhausted resistance increases until reaches about 100 ohms battery shows terminal voltage around 10 VDC numbers look small until consider multiply four get pack resistance add some ohms account welded tabs soldered joints wire plug Figure flight pack will vary depending its state charge Multiply resistance current Continued page 106 May1981 103 Shes surprisingly easy handle. can really get up go. WING SPAN 56 rfster LENGTH 39 WEIGHT 5-6 LBS POWER 40 C0VERITE 420 BABYLON RD 1-IORSHAM PA 19044
Edition: Model Aviation - 1981/05
Page Numbers: 16, 17, 18, 19, 20, 98, 102, 103
NO OCR TEXT NO OCR TEXT Author-designer-builder Bob Owens poses prior start local Sailplane Contest standard models Note slender fuselage generous tail moment arm Airfoil undercambered Eppler 387 Hard balsa plywood speci fied experience has told wasnt quite strong enough Avoid use epoxy doesnt evaporate reduce weight Instead use aliphatic resin thinned about 30% water Use sparing ly double-glue high-stress areas suggest make apolicator small squeeze-bottle such Zaptpflon tube can layof glue get ti tail surfaces 54it wood except SI S4 balsa Resist temptatior substituting larger yr really much nree arneren versions Zephyr view Headed straight us first conventional tapered wing Number 2 subject article Red Job heavyweight 13 oz imagined Anyway repairs quickly easilybeen covered 280-grit wet-or-dry sandpaper Follow plans least first oneattached Supertape sandpaper holds place cutting straight edges sheet balsa Preplanniag Before starting construction layand cutting strip wood out radio plansboth side bottom viewsto assure will fit Compare theConstruction suggest getting dull w width index finger sure will fit inof way enthusiasm ri finger notch may wish adjust theyou havent built Peanut Sc fuselage size less depending thelately now time get inL width radio finger Now time tobuilding light Use new No 11 make decision little ii ace foron soft wood get clean cut foam padding around receiver ry soit isnt anything unusui better leave plastsurfaces except fin ar Make upakitofparts Youvedge LE kept ng long straight cut uscovering Bevel aluminum has truepermit least 30 14EY PW NJOThEP Rs OSF~RII 3/32X 1/4 BALSA 3/8DIA LJ3-ITENING HOLES/IFOR ALL FlN-RUER FRAMES 3/32X V2 SHEET13/32 SQ BRACES FIN BRACES /32 SHEET BALSALEADINGEOGE SPANS CENTER 10P BOTTOM C CENTER SECTION I/32PLYflO CENTER DIHEDRAL BRACENO4 3/B SCREW3/32X /4 HARD BALSA SFR I/4 20 NYLON BOLT THRU BALSA BLOCK HOLD DOWN OVER V32PLW FORNER I/16X /4 HARD BALSA SPARS TOP/BOTTOM VBX I/2SHEET BALSA TRAIUNG EDGE AND TIP 1/32 PLOD1/4 BALSA SERVO BLOCKSI/64PLtwOo FUSELAGEI/B X 1/4 BALSA1/32 PLYWCO BRACE1/32 SHEET BALSA CWERS DOUBLER AT GRIP AREALEADING EDGESSPANS TIP DIHEDRALLEADING EDGE TOP AM BOTTOM SOLID NOSE BLOCKI/BX T/8BOTTOM FIlL LENGTHCUT OUT BOTTOM FOR INDEX FINGER FULL-SIZE PLANS AVAILABLE. SEE PAGE 132 5/52 SPAR-WOWOW-- W7 -.- . n-r4 _____ BALSAWRAWH VERTICAlwir SOWIWASPARSWEBN IA ROLE 2W2WZWI_WI N10 01/2 TE STOCK WAILD WWA SAME AS IOil{jREj~1FLAT NOTTOW ERCEPT sSTICK WONOKOTE TO IoTo L~7iWAJV~ALATTEACH OW AFTER SHBIMKNW IIWREORAL BRACES S-~1/52 NOTES ALL RALSA PARTS CONTEST GRADE SOFT ERCEPT WINO & ELED SPARS SI & OH ARE WARS FOR H 2 BALANCE LEVEL AT WING BOLT J FD FBNO205W SCREW WOOWED PAPER CUP OPTORAL TOW HOOK WN OWEN 0 BA ENDEO-N-BOOSSALUGAN NO SOi1 WADDER ELEG HOIRN I/IN PLO/bITS 3/02 ITjRECEIDER OoER%\At FI4JF5Nj~j7-TB I/HF I/NO PlO DOSBIERFA FUSE SIDES 5/52FID FIN ssoBONOGOTE GINHES TI5/FI SERVO WLOCKS FINOER WESTISOTUNRO WEIIDATLIWED OT NO CONDAIT I/A S D/W ANOER NDTH-COTaIT FBI SODA STRAW IWING SPAN021K AFTER FOSE ISAOGEBWAKDP WA WOLEIRI FFR FASE BOTTOM 12WWINOAREA330 ODIN FFRAIOATLINED 851WEIGAT LASS WADE 5 00 AIRFOIL EPPLER 5W FWI/R_____________ IOI-I/HSI-5/ARRLGANDOERLDCK5/SD O5FANFIILFSFN SOAWLERSz 1/52 PLY CUTWWGT EDDESIGNED ADRAWNWT WOW OWENS TO FIT F direction elevator similarily beveled Wing Pin down lower spar wing outer rib dihedral break Add vertical least same travel Notch rudder panel blocking up 1/32-in allow shear webbing dihedral brace Finish off elevator accept control horns Leave sheeting later LE also blocked up adding top spar Wet spar last rib tail structure pinned-down ample time height ribs Pin down trailing edge TE facilitate bending down tip glue set up hard tip glue ribs place except omit Continued page 98 20 Model Aviation WITfl ama DU155 spars EflO one-piece wing strongthanks shear webs fully sheeted leading edge forms rigid structural box Tail surfaces fragile adequate ..hors completed framework ready cover weIghed 3 02 wIthout radio Careful weight control needed prevent climbing 502 Use thinned aliphatic resin sparingly pre-sand balsa parts Author refers fuselage building half-shell Kraft KPS 18 servos built mounted screws permit easy removal Note routing control rods antenna conduit Theres ample space 6-ch Kraft receiver skinny case 225 mAh batterywith case bantamsize servos Fuselage width can bevaried accommodate own radio componentswithin reason FUN SCALE IS ilERE Easier Fly Yet Very Maneuverable Over 20 step-by-step building illustrations easier follow photos Lands Like Trainer Ideal 2nd Trainer Novice 19-25 Engine 19-40 Eng Span 51 Area 490 sq 18-20 oz wing loading 3*-4 lbs Upright Engine Can Built Flown 7 Days Due New Construction Techniques WILL FLY AS SLOW AS PIPER CUB MODEL Write free Catalog JEMCO 1305 Foothill Dr Vista CA 92083 714 724-3242 Zephyr Owens Continued page 20 Build inner wing panels same man ner join outer panel inner panel just before adding top spar Turn plans over build opposite wing Join right left wing halves first adding center dihedral brace add bolt block center rib cut fitted between LE spar between block TE Add LE sheeting following sequence lower inner panels lower outer panels upper inner panels upper outer panels Next add lower center panel upper center panels Sand weigh sand some Since sheeting usually warped edges must trim off slice straightedge mentioned earlierbefore trying glue wing fuselage will built up half shellso speak insufficient space down inside fuselage much work after boxed Everything possible will completed prior installing left side fuselage Attach doublers F7 F9 inside fuselage side F2 Use Hot Stuff Zap Jet make left right side Throughout instructions will refer Hot Stuff can take pick of cyanoacrylate glues Lay right side over side view plans glue place nose block Fl formers F3 F4A F4B F5 fuselage tapers between F3 FS width cross members must carefully measured achieve good fit left side put place Before gluing parts place lay straightedge across F3 F4 F4 F5to sure have good fit Add servo mounting blocks F14 F15 F16 F17 spaced according specific servos Again test fit using straightedge prefer servo tape can omit blocks Add parts make up cavity finger notch Fli F12 F13 Install servos add rudder elevator pushrod housings Gold-N-Rod #507 Attach hous ings right side 3 using baking soda Hot Stuff Make up pushrod cable-end-fitting Z-clips using soft wiresuch paper clipsof proper diameter fit holes servo arms Cut pieces copper tubing 5/16-in long Gold-N-Rod solder Z-clips forward end pushrod cables solder aft end fittings until final assembly Now excellent time test direction servo rotation pushrod travel sure rudder elevator move proper direction usually get wrong least control time Kraft System use dot servo rudder control install behind wing bolt because receiver has pigtail aileron connector negates possible need servo cable extender elevator servo standard no dot complete fuselage half-shell add 3/32 sq balsa strips F3 left right fuselage sides between wing tail Trial-fit soda straw cocktail straw fuselage serve antenna conduit Bevel aft end side tail post Glue left fuselage side place directly over right side except tail post using modeling clamps hold square Glue fuselage bottom F8 bring sides together tail post bottom fits between sides serves align entire fuselage straight true Install antenna conduit using Hot Stuff Continued page 102 ALL parts cut shape 0 Unique wing construction eliminates dihedral braces wing sheeting DesIgned Iron-on coverings Bottom view rear end shows rudder pushrod cable end fitting rudder notched passage elevator spar receiver antenna exiting soda-straw conduit 1/16 ply rudder horn l3WC QLD THE NEW FIREBALL GLOW PLUGS ARE LEAKPROOF AND BLOWOUT PROOF EVEN FOR THE NEW MONSTER ENGINES BUT THEY ARE STILL THE OLD PRICE OF $110 WRITE NOW! SWANSON P0 Box 151 Wayne NJ 07470 L 98 Model Aviation WINDSOR PROPELLER CO PO Box 112 Windsor CA 95492 Winning Ideas FOURMOST FUEL MANIFOLD o ww o 0 114FUEL SHUT OFFSma Fue Pitting Set Manifold Provides ConvenientCan Used Control Fuel zeI 0PRICE $1 50 Method Tank Filling Draining endFlow Starting1 Tee 2 Elbows 1 Pen Blsdder Tee PrimingPositive Airborn Shutoff % IDPRICE $125PRICE $420 ANDS 00STRUT PAIRINGS Comes two - 23 Lengths cock A- -Th COamingTwo Sizes% 10 s geFue F gS Sze%IDPRCE $200 Packaged 2 Ft Size E ee 1E bowU P g PRICE $250 ngths either size $2 70Bo ii Made oe Fu Send SASE Complete Information FOURMOST 4040 24th Ave Forest Grove OR 97116 PRODUCTS Phone 503 357-2732 baking soda few turns sewing thread necessary Add top hatch hold-down F6 wing TE hold-down F 19 fuselage top sheeting Temporarily install wing using nylon bolt align wing square fuselage install trailing edge screw Glue Fl 9 top hatch F20 carve aft edge fit wing upper surface wing place place straightedge fuselage tail-rest check dihedral alignment between wing horizontal tail Remove shape sand nose block sand fuselage corners have building nothing large models will amazed fast small jobs go together Covering luse MonoKote because its strengthto-weight ratio spend little extra time planning executing multi-colored covering scheme have standardized scheme shown photos white metallic-blue tips splash yellow important bottom omit yellow use blue undersides wing tips horizontal stab/elevator gives excellent visibility variety sky conditions Zephyr gets up nearly out-of-sight hurry color contrast lower surfaces helpful keeping view longer arrange ment provides three points reference helps orienting direction flight pitch climb dive attitude Omit covering tail surfaces g1ued Hinge rudder elevator strip MonoKote least wideattached side opposite beveled edge Leave about 1/16-in space between fixed hinged portions allow freedom movement After MonoKote tightened wings attach undercambered ribs Final assembly Install radio switch top hatch way will leave hatch home left fuselage side just ahead wing above receiver made lightweight switch harness using tiny audio slide switch switches suitable power planes since subject intermit tent operation due vibration Leave out charging jack keep connected charger avoid carrying around extra weight Again install wing glue horizontal tail placewhile carefully aligning wing viewed rear Also note slot stab receive fin must centered fuselage aimed straight-away wing bolt Epoxy yes first time have called epoxy rudder elevator horns place Terminate cable pushrod Z-clips first turn radio center trim knobs rudder elevator surfaces must neutral positions solder end-fit tings place flight trim adjustments necessary longer shorter Z-clips can made up necessary correction Operate servos full-travel sure no binding Now make sure center-of-gravity CG balanced per plans get rid warps -in washout tips good Flying Thermal slope hand-launch mini hi-start take pick Initially suggest go over local park baseball diamond grass ouffield Start some gentle tosses adding little muscle build confidence Also start aim little higher soon will tossing up about 60 degrees getting 50 60 feet altitude top climb have best success stiff-arm toss sling getting waist shoulder keeps throwing arm away Its just like tosing hand grenades back WW II After have throwing down can push over top climb stalling walk over downwind edge bare infield baseball field sun hot relative ground wind blowing just might pick up little thermal breeze blowing best circle S-turnsalways turning winduntil get lift turns too tight will create lots wing lift lots drag same time Keep turns shallow practical wing will contribute altitude gain just going around circles always considered desert great place thermals isnt necessarily desert floor just too regnlar uniformthat unless can find place has few ridges barren spots have relatives live desert first visit after finishing prototype Zephyr took along morning hot clear calm couldnt get anything few wing wiggles occasional bump lift spotted little ditch someone dug lay water pipe foot-high ridge bare dirt took start bubble warm air its way up able work small amount lift generated several minutes time tiring work because have put model exactiy right spot time So much hand-launching desert Just kicks made mini hi-start using 25 102 Model Aviation MASIElI AIRSCRIW FLIGHTBOX KIT Master Airscrew Flight Box has features larger boxes compact handy arrangement parts cut imported mahogany plywood will take stain varnish paint finishes overall size 19Wx9Wx 12 high $ dat dealer postpaid California add 6% Sales Tax Propeller storage Gravity closed small parts storage 7/8 aluminum handle Complete instructions & fasteners FEATURES INCLUDE Space battery & meter panel Transmitter compartment Room gallon fuel ft 3/1 6-in flat rubber 100 ft I0-lb-test fishing line old antenna ribbon streamer place usual parachute optional tow hook shown plan worked very well yeilded better results desert hand-launching am sure would better twice length rubber line Maybe am just lazy Slope Soaring much liking especially late lazy afternoons wind down whisper just few Gliders left slopejust barely scratching out flight Zephyr really shines always last plane forced land can tossed up 50 ft above ridge just gentlest breezes will permit several passes problem very well yielded better results desert because youre still flying cant stay out brush down slope ridge Balance very important gentle forgiving little bird slow flight hand-launching speed range quite broad hand-launching easily going 50 mph launch leaves hand about 10 mph light lift can trimmed both conditions Thought would never ask get balance correct place will trimmed both conditions anything between throw up should go straight rock zooms up have too nose-heavy thats right nose-heavy too tail-heavy will tend arc downward slight dive both cases assumes have model adjusted relatively slow hands-off glide Without getting lengthy aerodynamic discussion extra nose weight causes extra up-elevator trim just keep model level during slow flight throw hard above trim speed up-elevator trim causes nose pull up can also test same thing gliding higher up Start slow-trimmed glide Gradually push nose down hold control stick same position model builds up speed tends pull out dive too nose-heavy dive steepens tail-heavy correct balance should continue same diving attitude started correct balance point Zephyr will loops rolls inverted flight dont expect inverted flight undercambered airfoil good upright flight decent wind slope should able maintain altitude inverted have Zephyr mastered make control surfaces sensitive travel better real fun Radio Technique/Myers Continued page 23 reason judge end-of-charge point voltage small part battery voltage lost across ammeter larger part lost inside battery batteries have internal resistance new AA-size nickle-cadmium battery will show about 035 ohms operating about 75% full charge As charge exhausted resistance increases until reaches about 100 ohms battery shows terminal voltage around 10 VDC numbers look small until consider multiply four get pack resistance add some ohms account welded tabs soldered joints wire plug Figure flight pack will vary depending its state charge Multiply resistance current Continued page 106 May1981 103 Shes surprisingly easy handle. can really get up go. WING SPAN 56 rfster LENGTH 39 WEIGHT 5-6 LBS POWER 40 C0VERITE 420 BABYLON RD 1-IORSHAM PA 19044
Edition: Model Aviation - 1981/05
Page Numbers: 16, 17, 18, 19, 20, 98, 102, 103
NO OCR TEXT NO OCR TEXT Author-designer-builder Bob Owens poses prior start local Sailplane Contest standard models Note slender fuselage generous tail moment arm Airfoil undercambered Eppler 387 Hard balsa plywood speci fied experience has told wasnt quite strong enough Avoid use epoxy doesnt evaporate reduce weight Instead use aliphatic resin thinned about 30% water Use sparing ly double-glue high-stress areas suggest make apolicator small squeeze-bottle such Zaptpflon tube can layof glue get ti tail surfaces 54it wood except SI S4 balsa Resist temptatior substituting larger yr really much nree arneren versions Zephyr view Headed straight us first conventional tapered wing Number 2 subject article Red Job heavyweight 13 oz imagined Anyway repairs quickly easilybeen covered 280-grit wet-or-dry sandpaper Follow plans least first oneattached Supertape sandpaper holds place cutting straight edges sheet balsa Preplanniag Before starting construction layand cutting strip wood out radio plansboth side bottom viewsto assure will fit Compare theConstruction suggest getting dull w width index finger sure will fit inof way enthusiasm ri finger notch may wish adjust theyou havent built Peanut Sc fuselage size less depending thelately now time get inL width radio finger Now time tobuilding light Use new No 11 make decision little ii ace foron soft wood get clean cut foam padding around receiver ry soit isnt anything unusui better leave plastsurfaces except fin ar Make upakitofparts Youvedge LE kept ng long straight cut uscovering Bevel aluminum has truepermit least 30 14EY PW NJOThEP Rs OSF~RII 3/32X 1/4 BALSA 3/8DIA LJ3-ITENING HOLES/IFOR ALL FlN-RUER FRAMES 3/32X V2 SHEET13/32 SQ BRACES FIN BRACES /32 SHEET BALSALEADINGEOGE SPANS CENTER 10P BOTTOM C CENTER SECTION I/32PLYflO CENTER DIHEDRAL BRACENO4 3/B SCREW3/32X /4 HARD BALSA SFR I/4 20 NYLON BOLT THRU BALSA BLOCK HOLD DOWN OVER V32PLW FORNER I/16X /4 HARD BALSA SPARS TOP/BOTTOM VBX I/2SHEET BALSA TRAIUNG EDGE AND TIP 1/32 PLOD1/4 BALSA SERVO BLOCKSI/64PLtwOo FUSELAGEI/B X 1/4 BALSA1/32 PLYWCO BRACE1/32 SHEET BALSA CWERS DOUBLER AT GRIP AREALEADING EDGESSPANS TIP DIHEDRALLEADING EDGE TOP AM BOTTOM SOLID NOSE BLOCKI/BX T/8BOTTOM FIlL LENGTHCUT OUT BOTTOM FOR INDEX FINGER FULL-SIZE PLANS AVAILABLE. SEE PAGE 132 5/52 SPAR-WOWOW-- W7 -.- . n-r4 _____ BALSAWRAWH VERTICAlwir SOWIWASPARSWEBN IA ROLE 2W2WZWI_WI N10 01/2 TE STOCK WAILD WWA SAME AS IOil{jREj~1FLAT NOTTOW ERCEPT sSTICK WONOKOTE TO IoTo L~7iWAJV~ALATTEACH OW AFTER SHBIMKNW IIWREORAL BRACES S-~1/52 NOTES ALL RALSA PARTS CONTEST GRADE SOFT ERCEPT WINO & ELED SPARS SI & OH ARE WARS FOR H 2 BALANCE LEVEL AT WING BOLT J FD FBNO205W SCREW WOOWED PAPER CUP OPTORAL TOW HOOK WN OWEN 0 BA ENDEO-N-BOOSSALUGAN NO SOi1 WADDER ELEG HOIRN I/IN PLO/bITS 3/02 ITjRECEIDER OoER%\At FI4JF5Nj~j7-TB I/HF I/NO PlO DOSBIERFA FUSE SIDES 5/52FID FIN ssoBONOGOTE GINHES TI5/FI SERVO WLOCKS FINOER WESTISOTUNRO WEIIDATLIWED OT NO CONDAIT I/A S D/W ANOER NDTH-COTaIT FBI SODA STRAW IWING SPAN021K AFTER FOSE ISAOGEBWAKDP WA WOLEIRI FFR FASE BOTTOM 12WWINOAREA330 ODIN FFRAIOATLINED 851WEIGAT LASS WADE 5 00 AIRFOIL EPPLER 5W FWI/R_____________ IOI-I/HSI-5/ARRLGANDOERLDCK5/SD O5FANFIILFSFN SOAWLERSz 1/52 PLY CUTWWGT EDDESIGNED ADRAWNWT WOW OWENS TO FIT F direction elevator similarily beveled Wing Pin down lower spar wing outer rib dihedral break Add vertical least same travel Notch rudder panel blocking up 1/32-in allow shear webbing dihedral brace Finish off elevator accept control horns Leave sheeting later LE also blocked up adding top spar Wet spar last rib tail structure pinned-down ample time height ribs Pin down trailing edge TE facilitate bending down tip glue set up hard tip glue ribs place except omit Continued page 98 20 Model Aviation WITfl ama DU155 spars EflO one-piece wing strongthanks shear webs fully sheeted leading edge forms rigid structural box Tail surfaces fragile adequate ..hors completed framework ready cover weIghed 3 02 wIthout radio Careful weight control needed prevent climbing 502 Use thinned aliphatic resin sparingly pre-sand balsa parts Author refers fuselage building half-shell Kraft KPS 18 servos built mounted screws permit easy removal Note routing control rods antenna conduit Theres ample space 6-ch Kraft receiver skinny case 225 mAh batterywith case bantamsize servos Fuselage width can bevaried accommodate own radio componentswithin reason FUN SCALE IS ilERE Easier Fly Yet Very Maneuverable Over 20 step-by-step building illustrations easier follow photos Lands Like Trainer Ideal 2nd Trainer Novice 19-25 Engine 19-40 Eng Span 51 Area 490 sq 18-20 oz wing loading 3*-4 lbs Upright Engine Can Built Flown 7 Days Due New Construction Techniques WILL FLY AS SLOW AS PIPER CUB MODEL Write free Catalog JEMCO 1305 Foothill Dr Vista CA 92083 714 724-3242 Zephyr Owens Continued page 20 Build inner wing panels same man ner join outer panel inner panel just before adding top spar Turn plans over build opposite wing Join right left wing halves first adding center dihedral brace add bolt block center rib cut fitted between LE spar between block TE Add LE sheeting following sequence lower inner panels lower outer panels upper inner panels upper outer panels Next add lower center panel upper center panels Sand weigh sand some Since sheeting usually warped edges must trim off slice straightedge mentioned earlierbefore trying glue wing fuselage will built up half shellso speak insufficient space down inside fuselage much work after boxed Everything possible will completed prior installing left side fuselage Attach doublers F7 F9 inside fuselage side F2 Use Hot Stuff Zap Jet make left right side Throughout instructions will refer Hot Stuff can take pick of cyanoacrylate glues Lay right side over side view plans glue place nose block Fl formers F3 F4A F4B F5 fuselage tapers between F3 FS width cross members must carefully measured achieve good fit left side put place Before gluing parts place lay straightedge across F3 F4 F4 F5to sure have good fit Add servo mounting blocks F14 F15 F16 F17 spaced according specific servos Again test fit using straightedge prefer servo tape can omit blocks Add parts make up cavity finger notch Fli F12 F13 Install servos add rudder elevator pushrod housings Gold-N-Rod #507 Attach hous ings right side 3 using baking soda Hot Stuff Make up pushrod cable-end-fitting Z-clips using soft wiresuch paper clipsof proper diameter fit holes servo arms Cut pieces copper tubing 5/16-in long Gold-N-Rod solder Z-clips forward end pushrod cables solder aft end fittings until final assembly Now excellent time test direction servo rotation pushrod travel sure rudder elevator move proper direction usually get wrong least control time Kraft System use dot servo rudder control install behind wing bolt because receiver has pigtail aileron connector negates possible need servo cable extender elevator servo standard no dot complete fuselage half-shell add 3/32 sq balsa strips F3 left right fuselage sides between wing tail Trial-fit soda straw cocktail straw fuselage serve antenna conduit Bevel aft end side tail post Glue left fuselage side place directly over right side except tail post using modeling clamps hold square Glue fuselage bottom F8 bring sides together tail post bottom fits between sides serves align entire fuselage straight true Install antenna conduit using Hot Stuff Continued page 102 ALL parts cut shape 0 Unique wing construction eliminates dihedral braces wing sheeting DesIgned Iron-on coverings Bottom view rear end shows rudder pushrod cable end fitting rudder notched passage elevator spar receiver antenna exiting soda-straw conduit 1/16 ply rudder horn l3WC QLD THE NEW FIREBALL GLOW PLUGS ARE LEAKPROOF AND BLOWOUT PROOF EVEN FOR THE NEW MONSTER ENGINES BUT THEY ARE STILL THE OLD PRICE OF $110 WRITE NOW! SWANSON P0 Box 151 Wayne NJ 07470 L 98 Model Aviation WINDSOR PROPELLER CO PO Box 112 Windsor CA 95492 Winning Ideas FOURMOST FUEL MANIFOLD o ww o 0 114FUEL SHUT OFFSma Fue Pitting Set Manifold Provides ConvenientCan Used Control Fuel zeI 0PRICE $1 50 Method Tank Filling Draining endFlow Starting1 Tee 2 Elbows 1 Pen Blsdder Tee PrimingPositive Airborn Shutoff % IDPRICE $125PRICE $420 ANDS 00STRUT PAIRINGS Comes two - 23 Lengths cock A- -Th COamingTwo Sizes% 10 s geFue F gS Sze%IDPRCE $200 Packaged 2 Ft Size E ee 1E bowU P g PRICE $250 ngths either size $2 70Bo ii Made oe Fu Send SASE Complete Information FOURMOST 4040 24th Ave Forest Grove OR 97116 PRODUCTS Phone 503 357-2732 baking soda few turns sewing thread necessary Add top hatch hold-down F6 wing TE hold-down F 19 fuselage top sheeting Temporarily install wing using nylon bolt align wing square fuselage install trailing edge screw Glue Fl 9 top hatch F20 carve aft edge fit wing upper surface wing place place straightedge fuselage tail-rest check dihedral alignment between wing horizontal tail Remove shape sand nose block sand fuselage corners have building nothing large models will amazed fast small jobs go together Covering luse MonoKote because its strengthto-weight ratio spend little extra time planning executing multi-colored covering scheme have standardized scheme shown photos white metallic-blue tips splash yellow important bottom omit yellow use blue undersides wing tips horizontal stab/elevator gives excellent visibility variety sky conditions Zephyr gets up nearly out-of-sight hurry color contrast lower surfaces helpful keeping view longer arrange ment provides three points reference helps orienting direction flight pitch climb dive attitude Omit covering tail surfaces g1ued Hinge rudder elevator strip MonoKote least wideattached side opposite beveled edge Leave about 1/16-in space between fixed hinged portions allow freedom movement After MonoKote tightened wings attach undercambered ribs Final assembly Install radio switch top hatch way will leave hatch home left fuselage side just ahead wing above receiver made lightweight switch harness using tiny audio slide switch switches suitable power planes since subject intermit tent operation due vibration Leave out charging jack keep connected charger avoid carrying around extra weight Again install wing glue horizontal tail placewhile carefully aligning wing viewed rear Also note slot stab receive fin must centered fuselage aimed straight-away wing bolt Epoxy yes first time have called epoxy rudder elevator horns place Terminate cable pushrod Z-clips first turn radio center trim knobs rudder elevator surfaces must neutral positions solder end-fit tings place flight trim adjustments necessary longer shorter Z-clips can made up necessary correction Operate servos full-travel sure no binding Now make sure center-of-gravity CG balanced per plans get rid warps -in washout tips good Flying Thermal slope hand-launch mini hi-start take pick Initially suggest go over local park baseball diamond grass ouffield Start some gentle tosses adding little muscle build confidence Also start aim little higher soon will tossing up about 60 degrees getting 50 60 feet altitude top climb have best success stiff-arm toss sling getting waist shoulder keeps throwing arm away Its just like tosing hand grenades back WW II After have throwing down can push over top climb stalling walk over downwind edge bare infield baseball field sun hot relative ground wind blowing just might pick up little thermal breeze blowing best circle S-turnsalways turning winduntil get lift turns too tight will create lots wing lift lots drag same time Keep turns shallow practical wing will contribute altitude gain just going around circles always considered desert great place thermals isnt necessarily desert floor just too regnlar uniformthat unless can find place has few ridges barren spots have relatives live desert first visit after finishing prototype Zephyr took along morning hot clear calm couldnt get anything few wing wiggles occasional bump lift spotted little ditch someone dug lay water pipe foot-high ridge bare dirt took start bubble warm air its way up able work small amount lift generated several minutes time tiring work because have put model exactiy right spot time So much hand-launching desert Just kicks made mini hi-start using 25 102 Model Aviation MASIElI AIRSCRIW FLIGHTBOX KIT Master Airscrew Flight Box has features larger boxes compact handy arrangement parts cut imported mahogany plywood will take stain varnish paint finishes overall size 19Wx9Wx 12 high $ dat dealer postpaid California add 6% Sales Tax Propeller storage Gravity closed small parts storage 7/8 aluminum handle Complete instructions & fasteners FEATURES INCLUDE Space battery & meter panel Transmitter compartment Room gallon fuel ft 3/1 6-in flat rubber 100 ft I0-lb-test fishing line old antenna ribbon streamer place usual parachute optional tow hook shown plan worked very well yeilded better results desert hand-launching am sure would better twice length rubber line Maybe am just lazy Slope Soaring much liking especially late lazy afternoons wind down whisper just few Gliders left slopejust barely scratching out flight Zephyr really shines always last plane forced land can tossed up 50 ft above ridge just gentlest breezes will permit several passes problem very well yielded better results desert because youre still flying cant stay out brush down slope ridge Balance very important gentle forgiving little bird slow flight hand-launching speed range quite broad hand-launching easily going 50 mph launch leaves hand about 10 mph light lift can trimmed both conditions Thought would never ask get balance correct place will trimmed both conditions anything between throw up should go straight rock zooms up have too nose-heavy thats right nose-heavy too tail-heavy will tend arc downward slight dive both cases assumes have model adjusted relatively slow hands-off glide Without getting lengthy aerodynamic discussion extra nose weight causes extra up-elevator trim just keep model level during slow flight throw hard above trim speed up-elevator trim causes nose pull up can also test same thing gliding higher up Start slow-trimmed glide Gradually push nose down hold control stick same position model builds up speed tends pull out dive too nose-heavy dive steepens tail-heavy correct balance should continue same diving attitude started correct balance point Zephyr will loops rolls inverted flight dont expect inverted flight undercambered airfoil good upright flight decent wind slope should able maintain altitude inverted have Zephyr mastered make control surfaces sensitive travel better real fun Radio Technique/Myers Continued page 23 reason judge end-of-charge point voltage small part battery voltage lost across ammeter larger part lost inside battery batteries have internal resistance new AA-size nickle-cadmium battery will show about 035 ohms operating about 75% full charge As charge exhausted resistance increases until reaches about 100 ohms battery shows terminal voltage around 10 VDC numbers look small until consider multiply four get pack resistance add some ohms account welded tabs soldered joints wire plug Figure flight pack will vary depending its state charge Multiply resistance current Continued page 106 May1981 103 Shes surprisingly easy handle. can really get up go. WING SPAN 56 rfster LENGTH 39 WEIGHT 5-6 LBS POWER 40 C0VERITE 420 BABYLON RD 1-IORSHAM PA 19044
Edition: Model Aviation - 1981/05
Page Numbers: 16, 17, 18, 19, 20, 98, 102, 103
NO OCR TEXT NO OCR TEXT Author-designer-builder Bob Owens poses prior start local Sailplane Contest standard models Note slender fuselage generous tail moment arm Airfoil undercambered Eppler 387 Hard balsa plywood speci fied experience has told wasnt quite strong enough Avoid use epoxy doesnt evaporate reduce weight Instead use aliphatic resin thinned about 30% water Use sparing ly double-glue high-stress areas suggest make apolicator small squeeze-bottle such Zaptpflon tube can layof glue get ti tail surfaces 54it wood except SI S4 balsa Resist temptatior substituting larger yr really much nree arneren versions Zephyr view Headed straight us first conventional tapered wing Number 2 subject article Red Job heavyweight 13 oz imagined Anyway repairs quickly easilybeen covered 280-grit wet-or-dry sandpaper Follow plans least first oneattached Supertape sandpaper holds place cutting straight edges sheet balsa Preplanniag Before starting construction layand cutting strip wood out radio plansboth side bottom viewsto assure will fit Compare theConstruction suggest getting dull w width index finger sure will fit inof way enthusiasm ri finger notch may wish adjust theyou havent built Peanut Sc fuselage size less depending thelately now time get inL width radio finger Now time tobuilding light Use new No 11 make decision little ii ace foron soft wood get clean cut foam padding around receiver ry soit isnt anything unusui better leave plastsurfaces except fin ar Make upakitofparts Youvedge LE kept ng long straight cut uscovering Bevel aluminum has truepermit least 30 14EY PW NJOThEP Rs OSF~RII 3/32X 1/4 BALSA 3/8DIA LJ3-ITENING HOLES/IFOR ALL FlN-RUER FRAMES 3/32X V2 SHEET13/32 SQ BRACES FIN BRACES /32 SHEET BALSALEADINGEOGE SPANS CENTER 10P BOTTOM C CENTER SECTION I/32PLYflO CENTER DIHEDRAL BRACENO4 3/B SCREW3/32X /4 HARD BALSA SFR I/4 20 NYLON BOLT THRU BALSA BLOCK HOLD DOWN OVER V32PLW FORNER I/16X /4 HARD BALSA SPARS TOP/BOTTOM VBX I/2SHEET BALSA TRAIUNG EDGE AND TIP 1/32 PLOD1/4 BALSA SERVO BLOCKSI/64PLtwOo FUSELAGEI/B X 1/4 BALSA1/32 PLYWCO BRACE1/32 SHEET BALSA CWERS DOUBLER AT GRIP AREALEADING EDGESSPANS TIP DIHEDRALLEADING EDGE TOP AM BOTTOM SOLID NOSE BLOCKI/BX T/8BOTTOM FIlL LENGTHCUT OUT BOTTOM FOR INDEX FINGER FULL-SIZE PLANS AVAILABLE. SEE PAGE 132 5/52 SPAR-WOWOW-- W7 -.- . n-r4 _____ BALSAWRAWH VERTICAlwir SOWIWASPARSWEBN IA ROLE 2W2WZWI_WI N10 01/2 TE STOCK WAILD WWA SAME AS IOil{jREj~1FLAT NOTTOW ERCEPT sSTICK WONOKOTE TO IoTo L~7iWAJV~ALATTEACH OW AFTER SHBIMKNW IIWREORAL BRACES S-~1/52 NOTES ALL RALSA PARTS CONTEST GRADE SOFT ERCEPT WINO & ELED SPARS SI & OH ARE WARS FOR H 2 BALANCE LEVEL AT WING BOLT J FD FBNO205W SCREW WOOWED PAPER CUP OPTORAL TOW HOOK WN OWEN 0 BA ENDEO-N-BOOSSALUGAN NO SOi1 WADDER ELEG HOIRN I/IN PLO/bITS 3/02 ITjRECEIDER OoER%\At FI4JF5Nj~j7-TB I/HF I/NO PlO DOSBIERFA FUSE SIDES 5/52FID FIN ssoBONOGOTE GINHES TI5/FI SERVO WLOCKS FINOER WESTISOTUNRO WEIIDATLIWED OT NO CONDAIT I/A S D/W ANOER NDTH-COTaIT FBI SODA STRAW IWING SPAN021K AFTER FOSE ISAOGEBWAKDP WA WOLEIRI FFR FASE BOTTOM 12WWINOAREA330 ODIN FFRAIOATLINED 851WEIGAT LASS WADE 5 00 AIRFOIL EPPLER 5W FWI/R_____________ IOI-I/HSI-5/ARRLGANDOERLDCK5/SD O5FANFIILFSFN SOAWLERSz 1/52 PLY CUTWWGT EDDESIGNED ADRAWNWT WOW OWENS TO FIT F direction elevator similarily beveled Wing Pin down lower spar wing outer rib dihedral break Add vertical least same travel Notch rudder panel blocking up 1/32-in allow shear webbing dihedral brace Finish off elevator accept control horns Leave sheeting later LE also blocked up adding top spar Wet spar last rib tail structure pinned-down ample time height ribs Pin down trailing edge TE facilitate bending down tip glue set up hard tip glue ribs place except omit Continued page 98 20 Model Aviation WITfl ama DU155 spars EflO one-piece wing strongthanks shear webs fully sheeted leading edge forms rigid structural box Tail surfaces fragile adequate ..hors completed framework ready cover weIghed 3 02 wIthout radio Careful weight control needed prevent climbing 502 Use thinned aliphatic resin sparingly pre-sand balsa parts Author refers fuselage building half-shell Kraft KPS 18 servos built mounted screws permit easy removal Note routing control rods antenna conduit Theres ample space 6-ch Kraft receiver skinny case 225 mAh batterywith case bantamsize servos Fuselage width can bevaried accommodate own radio componentswithin reason FUN SCALE IS ilERE Easier Fly Yet Very Maneuverable Over 20 step-by-step building illustrations easier follow photos Lands Like Trainer Ideal 2nd Trainer Novice 19-25 Engine 19-40 Eng Span 51 Area 490 sq 18-20 oz wing loading 3*-4 lbs Upright Engine Can Built Flown 7 Days Due New Construction Techniques WILL FLY AS SLOW AS PIPER CUB MODEL Write free Catalog JEMCO 1305 Foothill Dr Vista CA 92083 714 724-3242 Zephyr Owens Continued page 20 Build inner wing panels same man ner join outer panel inner panel just before adding top spar Turn plans over build opposite wing Join right left wing halves first adding center dihedral brace add bolt block center rib cut fitted between LE spar between block TE Add LE sheeting following sequence lower inner panels lower outer panels upper inner panels upper outer panels Next add lower center panel upper center panels Sand weigh sand some Since sheeting usually warped edges must trim off slice straightedge mentioned earlierbefore trying glue wing fuselage will built up half shellso speak insufficient space down inside fuselage much work after boxed Everything possible will completed prior installing left side fuselage Attach doublers F7 F9 inside fuselage side F2 Use Hot Stuff Zap Jet make left right side Throughout instructions will refer Hot Stuff can take pick of cyanoacrylate glues Lay right side over side view plans glue place nose block Fl formers F3 F4A F4B F5 fuselage tapers between F3 FS width cross members must carefully measured achieve good fit left side put place Before gluing parts place lay straightedge across F3 F4 F4 F5to sure have good fit Add servo mounting blocks F14 F15 F16 F17 spaced according specific servos Again test fit using straightedge prefer servo tape can omit blocks Add parts make up cavity finger notch Fli F12 F13 Install servos add rudder elevator pushrod housings Gold-N-Rod #507 Attach hous ings right side 3 using baking soda Hot Stuff Make up pushrod cable-end-fitting Z-clips using soft wiresuch paper clipsof proper diameter fit holes servo arms Cut pieces copper tubing 5/16-in long Gold-N-Rod solder Z-clips forward end pushrod cables solder aft end fittings until final assembly Now excellent time test direction servo rotation pushrod travel sure rudder elevator move proper direction usually get wrong least control time Kraft System use dot servo rudder control install behind wing bolt because receiver has pigtail aileron connector negates possible need servo cable extender elevator servo standard no dot complete fuselage half-shell add 3/32 sq balsa strips F3 left right fuselage sides between wing tail Trial-fit soda straw cocktail straw fuselage serve antenna conduit Bevel aft end side tail post Glue left fuselage side place directly over right side except tail post using modeling clamps hold square Glue fuselage bottom F8 bring sides together tail post bottom fits between sides serves align entire fuselage straight true Install antenna conduit using Hot Stuff Continued page 102 ALL parts cut shape 0 Unique wing construction eliminates dihedral braces wing sheeting DesIgned Iron-on coverings Bottom view rear end shows rudder pushrod cable end fitting rudder notched passage elevator spar receiver antenna exiting soda-straw conduit 1/16 ply rudder horn l3WC QLD THE NEW FIREBALL GLOW PLUGS ARE LEAKPROOF AND BLOWOUT PROOF EVEN FOR THE NEW MONSTER ENGINES BUT THEY ARE STILL THE OLD PRICE OF $110 WRITE NOW! SWANSON P0 Box 151 Wayne NJ 07470 L 98 Model Aviation WINDSOR PROPELLER CO PO Box 112 Windsor CA 95492 Winning Ideas FOURMOST FUEL MANIFOLD o ww o 0 114FUEL SHUT OFFSma Fue Pitting Set Manifold Provides ConvenientCan Used Control Fuel zeI 0PRICE $1 50 Method Tank Filling Draining endFlow Starting1 Tee 2 Elbows 1 Pen Blsdder Tee PrimingPositive Airborn Shutoff % IDPRICE $125PRICE $420 ANDS 00STRUT PAIRINGS Comes two - 23 Lengths cock A- -Th COamingTwo Sizes% 10 s geFue F gS Sze%IDPRCE $200 Packaged 2 Ft Size E ee 1E bowU P g PRICE $250 ngths either size $2 70Bo ii Made oe Fu Send SASE Complete Information FOURMOST 4040 24th Ave Forest Grove OR 97116 PRODUCTS Phone 503 357-2732 baking soda few turns sewing thread necessary Add top hatch hold-down F6 wing TE hold-down F 19 fuselage top sheeting Temporarily install wing using nylon bolt align wing square fuselage install trailing edge screw Glue Fl 9 top hatch F20 carve aft edge fit wing upper surface wing place place straightedge fuselage tail-rest check dihedral alignment between wing horizontal tail Remove shape sand nose block sand fuselage corners have building nothing large models will amazed fast small jobs go together Covering luse MonoKote because its strengthto-weight ratio spend little extra time planning executing multi-colored covering scheme have standardized scheme shown photos white metallic-blue tips splash yellow important bottom omit yellow use blue undersides wing tips horizontal stab/elevator gives excellent visibility variety sky conditions Zephyr gets up nearly out-of-sight hurry color contrast lower surfaces helpful keeping view longer arrange ment provides three points reference helps orienting direction flight pitch climb dive attitude Omit covering tail surfaces g1ued Hinge rudder elevator strip MonoKote least wideattached side opposite beveled edge Leave about 1/16-in space between fixed hinged portions allow freedom movement After MonoKote tightened wings attach undercambered ribs Final assembly Install radio switch top hatch way will leave hatch home left fuselage side just ahead wing above receiver made lightweight switch harness using tiny audio slide switch switches suitable power planes since subject intermit tent operation due vibration Leave out charging jack keep connected charger avoid carrying around extra weight Again install wing glue horizontal tail placewhile carefully aligning wing viewed rear Also note slot stab receive fin must centered fuselage aimed straight-away wing bolt Epoxy yes first time have called epoxy rudder elevator horns place Terminate cable pushrod Z-clips first turn radio center trim knobs rudder elevator surfaces must neutral positions solder end-fit tings place flight trim adjustments necessary longer shorter Z-clips can made up necessary correction Operate servos full-travel sure no binding Now make sure center-of-gravity CG balanced per plans get rid warps -in washout tips good Flying Thermal slope hand-launch mini hi-start take pick Initially suggest go over local park baseball diamond grass ouffield Start some gentle tosses adding little muscle build confidence Also start aim little higher soon will tossing up about 60 degrees getting 50 60 feet altitude top climb have best success stiff-arm toss sling getting waist shoulder keeps throwing arm away Its just like tosing hand grenades back WW II After have throwing down can push over top climb stalling walk over downwind edge bare infield baseball field sun hot relative ground wind blowing just might pick up little thermal breeze blowing best circle S-turnsalways turning winduntil get lift turns too tight will create lots wing lift lots drag same time Keep turns shallow practical wing will contribute altitude gain just going around circles always considered desert great place thermals isnt necessarily desert floor just too regnlar uniformthat unless can find place has few ridges barren spots have relatives live desert first visit after finishing prototype Zephyr took along morning hot clear calm couldnt get anything few wing wiggles occasional bump lift spotted little ditch someone dug lay water pipe foot-high ridge bare dirt took start bubble warm air its way up able work small amount lift generated several minutes time tiring work because have put model exactiy right spot time So much hand-launching desert Just kicks made mini hi-start using 25 102 Model Aviation MASIElI AIRSCRIW FLIGHTBOX KIT Master Airscrew Flight Box has features larger boxes compact handy arrangement parts cut imported mahogany plywood will take stain varnish paint finishes overall size 19Wx9Wx 12 high $ dat dealer postpaid California add 6% Sales Tax Propeller storage Gravity closed small parts storage 7/8 aluminum handle Complete instructions & fasteners FEATURES INCLUDE Space battery & meter panel Transmitter compartment Room gallon fuel ft 3/1 6-in flat rubber 100 ft I0-lb-test fishing line old antenna ribbon streamer place usual parachute optional tow hook shown plan worked very well yeilded better results desert hand-launching am sure would better twice length rubber line Maybe am just lazy Slope Soaring much liking especially late lazy afternoons wind down whisper just few Gliders left slopejust barely scratching out flight Zephyr really shines always last plane forced land can tossed up 50 ft above ridge just gentlest breezes will permit several passes problem very well yielded better results desert because youre still flying cant stay out brush down slope ridge Balance very important gentle forgiving little bird slow flight hand-launching speed range quite broad hand-launching easily going 50 mph launch leaves hand about 10 mph light lift can trimmed both conditions Thought would never ask get balance correct place will trimmed both conditions anything between throw up should go straight rock zooms up have too nose-heavy thats right nose-heavy too tail-heavy will tend arc downward slight dive both cases assumes have model adjusted relatively slow hands-off glide Without getting lengthy aerodynamic discussion extra nose weight causes extra up-elevator trim just keep model level during slow flight throw hard above trim speed up-elevator trim causes nose pull up can also test same thing gliding higher up Start slow-trimmed glide Gradually push nose down hold control stick same position model builds up speed tends pull out dive too nose-heavy dive steepens tail-heavy correct balance should continue same diving attitude started correct balance point Zephyr will loops rolls inverted flight dont expect inverted flight undercambered airfoil good upright flight decent wind slope should able maintain altitude inverted have Zephyr mastered make control surfaces sensitive travel better real fun Radio Technique/Myers Continued page 23 reason judge end-of-charge point voltage small part battery voltage lost across ammeter larger part lost inside battery batteries have internal resistance new AA-size nickle-cadmium battery will show about 035 ohms operating about 75% full charge As charge exhausted resistance increases until reaches about 100 ohms battery shows terminal voltage around 10 VDC numbers look small until consider multiply four get pack resistance add some ohms account welded tabs soldered joints wire plug Figure flight pack will vary depending its state charge Multiply resistance current Continued page 106 May1981 103 Shes surprisingly easy handle. can really get up go. WING SPAN 56 rfster LENGTH 39 WEIGHT 5-6 LBS POWER 40 C0VERITE 420 BABYLON RD 1-IORSHAM PA 19044