Der Fle

NO OCR TEXT NO OCR TEXT Der Fledermaus sitting half-mile-long concrete runway available Conoors i-lying Club Luke AFB Arizona flat-bottomed polyhedral wing quite apparent angle model very stable wing configuration making great low-wing trainer cockpit Der Fledermaus tail-dragger its gear wings Though borrowed German name Fledermaus intended Scale Stand-off Scale model full-size ship Its lines similar original aircraft identical Der Fledermaus has 9-in airfoil dermaus its bare bones sanded ready covering Construction straightfor ward should present no difficulty decide build three- channel control think might want go four-channel future its best build ailerons lock place Modifying finished wing add ailerons linkage would difficult 26 Model Aviation author holding latest creation lie re ports model has excellent flight char acteristics performs standard ma neuvers stable flies inverted aspect ratio approximately 61 giving wingspan around 57 inches actually used 54-in span making panel 27 inches neatly divided nine 3-in wing bays Three-inch rib spacing allows vertical webbing cut stock balsa Also 26-in-wide MonoKote leaves narrow 2-in section center wing may covered contrast ing color used other design parameters gleaned Chuck Cunningham Ro mey Bukolt articles published past issues various hobby magazines Construction materials list included article Collect necessary materials kit plane first cutting out ribs spars trailing edge TE ailerons longerons shape length Make pattern cut out fuselage sides Cut out firewall fuselage formers cut em pennage pieces shape may glue pieces appropriate units point Wings Before beginning wing construc Over-the-shoulder view cockpit pilot sits removable 1/16-in aircraft ply cockpit cover has covered black MonoKote instrument bezels small sections brass tubing cut epox led place windshield trimmed white striping tape Access servos fuel tank through cockpit opening iJer Medermaus sitting its custom-made Pvt cradle atop what appears rather elab orate field box foldup legs complete built-in electrical fueling connections der fledermaus PAUL DENSON - BRLSA CPP STRIPS BRLSR RIBS 4 LITE PLY BRLSF1 ShEET SHEET BRLR K N AK -4 N K BPLSR 4 DO WEtS // P SKEfT C I- . -o C - - A--0 7. - BPL3P SHEET I6 SQSPRUCE LONGERONS SQ SPLEP ___ 41 x P DOUBLER N465H5Er BRLSR 36-4 MLS8rE DOWEL 6PLY LRMINRTED U Xs BRLSR WE BRRCE Zk ISHEEL N -7/I / N N V SIG STOCK 76 BRLSR 3IIEET 20-Z5 SIZE ENGINE 2-STROKE %x J-PESTOCA B615R 2- WbIEEL 0 0 0 tion have decision make want three- four-channel control Der Fledermaus designed aileron train er will fly beautifully rudder/elevator control really want build three-channel think might want convert later build aileron version ailerons lock place center wing pushrods meet wing built flat four sections will joined later put polyhedral As far know idea installing Sig symmetrical leading edge LE stock angle flat-bottomed wings originated Doc Mathews My0-My works great Thanks Doc Begin construction section pin ning bottom A-in-sq spruce spar plans use waxed paper Saran wrap tween plan structure Using ribs spacers pin x %-in TB stock plan Insert ribs except two cen ter ribs two dihedral joint ribs Glue top spar LB place stalling LE sure maintain /6-in overlap top bottom allow fit ting LE sheeting Install /6 x A-in TE fillers four wing panels installing ailerons outboard panels pin TB filler stock will become ailerons position through TB Use no glue center line Sand TB fair tapered TB filler Some photos show triangular fillets between TB ribs found us ing cap strips rendered fillets unneces sary four panels structurally com plete its time join polyhe dral unit Leave inboard panel pinned building board prop up out board panel measure 1 /2 board surface wing tip Check di hedral joint fit sand correct bevel Bpoxy A6 ply spar TB dihe dral braces place making sure main tain correct angle alignment curing Dont glue TB filler butt joints Fit glue dihedral joint ribs place same procedure applies other board outboard wing panels Assemble two wing halves pinning inboard panel building board propping up other measure inch board surface polyhe dral joint Sand upper lower spars leading trailing edge butts snug fit Double-check alignment gle pin spars LB TB butts place glue together cured clamp spar TB ply dihedral braces 28 Model Aviation installed K&B 20 Sportster engine Care fully align position engine mount before final drilling mounting make sure muffler doesnt contact fu selage After engine installed bot tom front sheeting can put place An inverted view partially finished engine compartment showing engine mount %2-in nose wheel assembly nose wheel steering pushrod throttle control cable place Note entire engine compartment has thoroughly fuel-proofed partially finished nose section beveled instrument panel has braced former Fl front side cowl panels place Note blind nuts back firewall strong triangular bracing top paneling goes after fuel tank installed Make sure provision made removing fuel tank through cockpit opening servo compartment looking aft three servos accessed through re movable ply cockpit deck receiver tightly wrapped foam installed ward crosswise throttle servo el evator rudder pushrods place Bottom view servos looking through wing mount opening plywood servo rails wing hold-down anchors visible shot wing anchors drilled tapped 1/420 nylon wing bolts leading edge wing held place us ing -in dowel socket arrangement place making sure dont protrude above below upper lower spars Once youre satisfied fit epoxy braces place Cut fit vertical-grain webbing glue place Trim /16 x 2-in balsa inboard out board TE sheeting top bottom rear turtledeck made up A-in dowels run between formers F2A F5 top formers F3 F4 I/ balsa filler pieces between dowels sanded arc Dremel tool sanding drum cut width glued place finished 3/,-in sheet tail assembly plans call cross-grained caps tne tin rudder thwart warping soft balsa fillet between stabilizer fin shown pinned place final shaping fillet tail surfaces should covered before assembly sure carefully remove covering material bonding surfaces May 1990 29 shot partially finished nose section shows fuel tank installed Note fuel tubing also place temporarily joined keep dust out tubes tank length epoxy place Mark line outboard TE sheeting show separate aileron Glue two center wing No ribs toA SIG LE STOCK SRXAA K--- _8 76--4y4- BING ------ ---------- o B L IT F IIRPLV DIHEDRAL LBRIr BALSABRACES IPIRSATRALSA C HA SUEt WINS Li_ I_ -------j---- LA DIREDRA BRACE TEDIHEDRALIIRPLY BRACE PD LV U E DR COWL SIDE IB BALSA TI/ROT TLE 3/lB SU V BA LSA I3/lB SOBALSA PB BALSAFIREWALL F II/APLY I/R PLY 0BLERRS B.20 SPOOTATER IBDI/4RALSACI DABBO BARFl TANKBATTERY BALSACYB 3IRBACSA DOUBLERWIOBIIbBBDARSBDBABE 3/lB BALSA ZYASRREEL2gether dry cut fit glue place Add /16 x 2A -in balsa upper LE sheeting gluing snugly LE spar Install bottom LE sheeting add bottom center sheeting Install IA ribs positioning ac cordance size servo Cut fit %2 ply servo mount between ribs Set wing aside until later Fuselage Make right left fuselage side A-in sheet balsa Add /6 spruce longerons wing cradle doublers vertical /8 x /16 braces aft wing position Mark lines inner sur faces sides formers firewall Lay right side over plan side view Install former Fl F2 checking verti cal alignment Remove structure side view place over top view wing attachment point facing down Glue left side place using masking tape pins hold position until glue sets Bring aft ends together over center line glue clamp until dry Drill holes firewall fuel lines throttle pushrod nose wheel block pushrod Install blind mounting nuts Install firewall fuselage epoxy using padded clamps until its dry Remember firewall must installed will provide 3D downthrust engine Glue side-to-side cross braces A/I B BA LA YR BALSA CA 30 Model Aviation Above Its easier build wing kitting first ribs top cut using up per plywood template ensure uniformity rib butted against trailing edge block middle spar notches may cut uniformly bottom template used make identical wing tips %-in balsa Below Close-up structur ally complete wing showing some details plywood landing gear mount ail eron pushrod Short pieces inner Gold-NRod sleeves inserted rib giv ing exceedingly smooth pushrod movement Above aileron pushrod between ail eron horn belicrank passes through rectangular hole sheet balsa cover ing support gussets seen photo shown plans cap strips ribs obviate necessity Below bellcrank installed its plywood mount pushrods attached bellcrank Z-bends aileron hinged very near top surface see plan Full-Size Plans AvailableSee Page 202 N I/IsSoEETIso ____ SAi----I-I--TI nrnI/IRPLY DIgEDRAL BRACED3/NROPT ML RIND 3/30 BALDA IIRP U RIREDRAL BRACEDDOUBLER RIRD ACRANNEL WIND IIII IAIAjfl 3/RU I/ARALDA YE O/IRAII/A TAPERED YE OTOCOzs' n--zz- - -- DIHED AL BRACE EDIACORAL PLY LANDING DEAR MOUNT B PLY LAMINATED WINOORIELD P3PAPD IN DO DPRUCE3/WSOBALSA I/B DOWELO PZAPA I/B ELD BRAISA FILL BALDA PILL 3/IN DO DPRRCE LONDERONO EDA I/N OUT BALSA SPAWN FOR CLARITY NYLON332 OUT BALDA 3/IR 00 BALSA /4A II2PLY DYANOARD RrB RIBO 3EA 3/32 A AIR PLY RIBS ZA RIB IA 3/3D BALSA 3/ IN SR T NALDA CUTAWAY FOB RADDER TAN L D 23~ topside formers keep strument panel correct angle y6-sq stringer installed between panel former Fl turtledeck aft cockpit made -in hardwood dowels glued between formers F2A F5 atop F3 F4 spaces between dowels next F2A filled A-in sheet balsa can cupped -in drum sander Dremel tool prior fitting Using pattern plans cut two sides front cowl A-in sheet balsa pattern should make bit oversize compensate double bevel Bevel bottom edges fit snug ly atop main longeron side panels glue place Sand top sur face sanding board making top main longerons Cover top cowl 346 cross grained sheet balsa center firewall forward cowl fashioned -in sheet balsa grain run ning lengthwise Sand top surface cowl achieve pleasing curve strument panel forward nose Cut opening cowl forward firewall accommodate engine tend use see plans opening should just wide enough allow engine slide slightly tilted engine will straightened out once bolting flanges have slipped inside fit engine engine mount insert mount bottom set engine mount Raise mount en gine high enough install muffler lower until muffler just clears top cowl locate mark engine mount holes Drill holes install blind nuts attach mount installed engine mount prematurely ended up having cut away /8 cowl surface Thats what call plan ning ahead Finally install wing hold-down blocks Empennage havent done already cut empennage surfaces /l6 sheet balsa After sanding surfaces smooth rounding edges install hinges recommend newer Sig hinges May 1990 31 DOWEL B SO WEL DER FLEDERMAUS I MODZR LOW WIND 3-ACRANNEL SPORT PLMNE DESIGNED & DRAWN NY PAUL P DENSON Left The 1A-in landing gear wire inserted slot plywood fabricated mount see construction drawing plans gear secured metal landing gear straps 1/4 x 1/wln balsa crosspiece behind gear added securing covering side opening Right servo puabrods have Du-Bro threaded couplers soldered inner ends pin has cut away vane left clevis other clvis holds system together plywood servo platform drilled ready receive servo case can glue place drop CyA cyanoacylate First glue hinges stationary surfaces cover surfac es glue movable surfaces hinges Other construction finish wing stall landing gear mounts ailerons control linkage /16 x A-in cap strips %-in balsa wing tips Cover ing very last operation landing gear shown plan made up laminating /8-in aircraft ply 10-in strip should long enough both mounts vertical supports opt commercial mount notches wings will have altered top bottom views photos plans should clarify structure Mount bellcranks between ribs 7 8 crossmember supports bellcrank /8-in Lite Ply cemented top Y6-sq balsa strips attached rib aileron pushrods connect servo bellcranks fabricated length /16 brazing rod music wire Form Z-bend outboard ends fit threaded couplers inboard ends pushrods ailerons made exactly same way Z-bend middle Dont solder threaded cou plers pntil control linkage installed checked correct alignment free movement aileron pushrods make straight run through polyhedral wings servo bellcranks originate near bottom wing servo pass through rib progressively higher point through nearly top rib No 6 polyhedral break Inner Golden Rod cut /2-in lengths glued ribs ensures free movement reduces vibration An easy way connect two devises servo cutting pin vane clevis overlaps other remaining pin used lock both devises servo see photos Use metal devises opt system Cover top wing center section add %-in balsa wing tips havent done already cut ailerons away TE outboard wing panels Bevel aileron leading edges hinge stall Install adjust pushrods between aileron horns belicranks Install pushrods fuselage After throttle nose wheel pushrods stalled engine cowling can finished sheet block balsa Drill hole A-in hold-down dowel center wing LE stall wing seated its cradle mark position dowel hole bottom former Fl Drill hole bit oversize Using cross-grained balsa strips same width wing-seating tape seat wing Carefully measure wing tip center fuselage tail end Square wing fuselage making sure two measurements identical Drill hole through wing TE wing hold-down block No 9 bit 32 Model Aviation finished tail sections ready hinging covering Installation sections cut 3A6-in sheet balsa tab fin Installed through narrow slot stabilizer completed aileron servo installation Futaba 9-28 servo mounted its case screwed servo platform Inner two ribs have slots cut away ai low up-and-down movement pushrod ELECTRIC CITABRIA great stand-way-ott scale fun ship designed 05/0 75 electric power take-offs aerobatics touch goes classic beauty yet enjoy docile slow flight easy landings Quick easy build kit includes pre cut fuselage sides tail feathers small parts step-by-step instructions complete rolled plans hardware threaded rods formed landing gear spruce spars shear webs 32 oz flying weight lightweight equipment 40 SPAN 275 SQ IN AREA FLAT BOTTOM WING 40 EJNIEQ1IEI& Electra-Combo includes kit DSC 075 Hyper thrust motor fused switch harness Tamiya style connector propeller adaptor 8/4 fiberglass propeller SPECIAL COMBO PRICE $5795 BASIC KIT $2995 IIAVEY YSTEMS675 Tower Lane West Chester PA 19380 qORPORATION 215 430-8645 thread block 4-20 tap Check threads 4-20 nylon bolt apply drop CyA both wing block holes retap Ream out wing hole A-in diameter Drill 4-in-dia hole center /2-in strip 2-in-long %2 ply Place strip over end wing holddown dowel forward side former Fl epoxy place Remove wing before epoxy sets up Cover bottom tank compart ment fuselage bottom back wing tail Sand entire struc ture smooth thoroughly clean surfac es Cover fuselage install foam wing-seating tape Carefully fuel-proof engine compartment before installing en gine engine Ive tried Der Fleder maus K&B 20 Sportster However 20-size two-cycle engine will work just well dont recommend fourcycle installation However 26 05 Surpass would probably work fine al though center-of-gravity would have adjusted compensate extra weight As rule wings airplanes size remain place since plane will fit almost automobile disassembly Radio gear access therefore primarily through cockpit cockpit cover made /16 ply has hold-down lip forward edge secured two screws fitted aft end use Futaba Conquest AM FP-T6NLK transmitter four S-38 servos mounted flat wing other three radio compartment cause no structural interference clearance adequate Flying Right beginning no doubt airplane would fly polyhedral wing stability its middle name Though ailerons hooked up just safe side discovered Der Fledermaus flies quite well rudder elevator Youll need use ai lerons rolls howeverthe polyhedral wing configuration just too much over come ailerons model rolls quite nicely serious doubts whether Der Fledermaus capable flying inverted its flat-bottomed polyhedral wing lieve first attempt fly verted able circle field three times wheels pointed skyward model will fly basic maneu vers leisurely pace Landings solid down down no bouncing airplane hugs runway present Im flying Der Fledermaus 34 rudder deflection right left elevator moves /2 up down high rate 4 low rate high rate ailerons move up % down % low rate move up % down 4 fly plane low rate time Continued page 154 May 1990 33 great companion very popular 40 Fly Baby 0 Mere Fun SPECIFICATIONS Wing Span62Y2 inches Wing Area770 square inches Engine Size10 cc 90 120 four stroke Designed forAMA FAI Turn-around pattern Foam wing stab 3-32 Balsa sheet covering Tricycle conven tional gear fixed retracts Rear side exhaust fiber glass canopy Veiy positive maneuverable XLT designed tuned pipe re tract landing gears Capable AMA Turn-around pattern Rear side ex haust SPECIFICATIONS Wing Span Wing Area Engine Size 63'a inches 700 square inches 50-60 Glow 90 four stroke fun sport pattern turn-around can done Utter Chaos completely built up Balsa construction Canopy engine mount included years proven flying reliablity BRIDI AIRCRAFT DESIGNS INC 23625 Pineforest Lane Harbor City California 90710 213 549-8264 326-5013 SEE YOUR FAVORITE HOBBY SHOP OR RETAIL OUTLETW Dealer Inquries Invited THE FIRST PRECISION-ENGINEERED ENGINE MOUNT THAT PROVIDES VIBRATION-DAMPING SOFT MOUNTING USA WITHOUT EXCESSIVE ENGINE SHAKE AT LOW RPM soft mounting excessive engine shake low RPM due damped nonlinear force-displacement characteristics ot mounting system Vibration mounts loaded compression shear Thrustforces cant causetension failures Constructed aluminum oil resistant elastomer Safety featureunique mount design captures engine airframe Light weightless standard aluminum hard mount Allows lighter front end construction Radial beam mounta available 40-65 7011 12-18 cu sizes hardware complete installation instructions included 60-day no-riak money-back guarantee direct orders Radial Meuaf $ 21w 4065 size hlp, 70-1 1 siZe $2495 121959 $2995 offwaie10319 Pine Pass Drive Houston DOAu~1 / ssOciates Vpz M2st,C4d COOS 95oopted Dwkp i oiirs tcoo LZA~MLttntsLJ ejow o , Safety/Preston Continued page 22 tors power tools nor Dremel back 1981 have either belt sander table saw might want check motor accumulated sawdust necessary vacuum out time read column hibernate during winter will about ready return flying field equipment going function just way did last year Maybe some servicing might order Meanwhile Have safe month Der Fledermaus/Denson Continued page 33 radio doesnt have dual rates set control surface movements somewhere between high low settings indicated above Differential movement aile rons necessary rock-stable trainer will bring much building flying fun its given Specifications Wingspan55/a wing chord9 wing area524 sq wing loading 166 oz/sq ft Elevator span20 elevator chord 5% avg elevator areai 15 sq Fin/rudder height36 width5 Fuselage length36 radio compart ment9 long 2/2 high 2 tn wide Recommended engine sizes20-25 twostroke 26 four-stroke Fuel tank6 oz Landing geartricycle Radio channelsthree four ailerons elevator rudder throttle Weight ready fly3 lb 60 oz Parts list Six /6 x 3 x 36-in balsa sheets wing sheeting Three %2 x 3 x 36-in balsa sheets wing ribs fuselage bottom Three / x 3 x 36-in balsa sheets front decking aft turtledeck formers fuse lage sides Two /t6 x 3 x 36-in balsa sheets rud der fin elevator fuselage bottom Four Y6-sq x 36-in spruce sticks fu selage longerons Four 3/6-sq x 36-in spruce sticks wing spars Two pieces % x 3/4 x 36-in Sig LE stock wing LE Two pieces % x x 36-in tapered balsa stock wing TE filler Two % x x 36-in balsa sticks wing TE spars 8-in-long length %-in triangular stock firewall doubler piece /16 aircraft ply wing dihedral braces piece A-in Lite Ply fuse lage formers bellcrank supports wings piece A-in aircraft ply doubleformer Fl piece %2 aircraft ply servo doubler wing piece A-in aircraft ply tATtlES MILLS METALS BOOKS PRECISOON INSTRUMENTS COMPLETE CATALOG $200 11000 r Ste. 0 4VPIISLDMJ Spron4t,ld 0I,o 45525 513 3229562 154 Model Aviation Bann Meunt 51 70-119 956w 1218 saIw Wing pan65 inches Length65 inches Wing Area845 square inches Recommended Engine Size10 cc 90 120 four stroke _________ STARLITE ST FLIGHT TRAINUW9 -13 WIJG SMN HAIO-LAIMOIED GUCEU 45y TC mAL FERI TO FLY tSsft FLK2BI5 COMPLETE CETAUD B PAGE MANUAL BALSA & HAIDWOCO 0T1 $595 beaadd*596taaI .* JAMMAESO P0 Ba I7 AtIadic4 23303 cal 1804 8240514 pisaw ad 5250 pingdalw nq,nsa kasd 1 WE BUILD YOUR HELl TEST YOUR HELl ~\REPAIRYOURHELI 322 North 7th St 61$ 4? 1 Lehighton Pa 18235 WRITE OR CALL FOR INFORMA TION firewall A-in-dia x 36-in-long length hardwood doweling turtledeck 4-in-dia x 3-in-long piece hard wood doweling wing hold-down length /g x 36-in-long music wire landing gear %2-in front landing gear assembly accessories Two 2/2-in wheels main landing gear 2-in wheel nose gear 6-oz Du-Bro equivalent fuel tank Assorted nuts bolts machine screws sheet metal screws devises threaded con nectors pushrod ends /16 brazing rod music wire /s-20 nyon wing hold-down bolts Gold-N-Rod pushrods 20- 25 two-stroke engine Appropriate glues fillers covering ma terials sundry items merchan dise may have forgotten include Radio Technique/Myers Continued page 35 pins voltages 48 four cells 60 five cells 72 six cells 84 seven cells 96 eight cells 108 nine cells Again label confusing because plug position actually refers number cells battery Actual cutoff takes place lower voltage probably take account voltage drops around circuit could otherwise cause cutoff happen too high voltage An LED light-emitting diodeRMcM display reports battery capacity cutoff percentage capacity selected discharge-current plug display actually measures elapsed time during discharge adequate cause discharge current held constant al ways use stopwatch performing battery discharge tests because elapsed time reli able indication performance piercing whistle signals end dis charge activity device does enter other mode after discharging terminates Testing unit Fast-charge testing ran several tests device notes typical test procedure charging function results follow Number cells/capacity battery 6 x 1000 mAh VDD-protected time-limited constant-current fast charger Charge current plug position 900 mA Charge/Efficiency switch position Charge under 84 VDC Measured charge current 11 mps DC 5A scale 5% analog ammeter Measured charge cutoff volts 840 DC 35-digit 1% digital voltmeter Measured trickle current pulsed DC 200 mA peak 20% cycle Time reach whistle 840 VDC 60 minutes integral timer [Notes Battery cool Doing discharge test point shows 80% charge 2 Press ing Stars button again point will stop whistle restart charging process] Time second whistle 921 VDC 14 addi tional minutes VDD cutoff INote Battery still cool Elapsed charging time about right full charge] piercing whistle signals end charge activity fast charging terminated charger drops trickle-charge mode Discharge testing As fast-charge section Multi Charge-A-Matic ran sev eral tests discharge function notes typical test procedure discharge function results follow Voltage-cutoff constant-current 2C dis chargerContinued page 158 May 1990 155 WIREMASTERm bendenlcoiler rho extra large handle bends 1/8-1/4 coils Si 32-3/16 music wire Wire creep eliminated ur ANTI-KREEP WIRE LOCK1 free catalog also has hardware accessories JOM COMPANY 114 WashIngton Terr Dept Waukegan IL 60066 Bob Fiorenze1 Hobby Center Inc Dealer Yellow Aircraft us Orders Shipped Daily_______ Now Available Fastcover covering Material Visit Oar Showroow 135 win frow Disney WorIdijJ NEW Castow Building Service 420 West SR 43414071327 6353 Winter Springs FL 32706 LW Fax 14071327-7148

NO OCR TEXT NO OCR TEXT Der Fledermaus sitting half-mile-long concrete runway available Conoors i-lying Club Luke AFB Arizona flat-bottomed polyhedral wing quite apparent angle model very stable wing configuration making great low-wing trainer cockpit Der Fledermaus tail-dragger its gear wings Though borrowed German name Fledermaus intended Scale Stand-off Scale model full-size ship Its lines similar original aircraft identical Der Fledermaus has 9-in airfoil dermaus its bare bones sanded ready covering Construction straightfor ward should present no difficulty decide build three- channel control think might want go four-channel future its best build ailerons lock place Modifying finished wing add ailerons linkage would difficult 26 Model Aviation author holding latest creation lie re ports model has excellent flight char acteristics performs standard ma neuvers stable flies inverted aspect ratio approximately 61 giving wingspan around 57 inches actually used 54-in span making panel 27 inches neatly divided nine 3-in wing bays Three-inch rib spacing allows vertical webbing cut stock balsa Also 26-in-wide MonoKote leaves narrow 2-in section center wing may covered contrast ing color used other design parameters gleaned Chuck Cunningham Ro mey Bukolt articles published past issues various hobby magazines Construction materials list included article Collect necessary materials kit plane first cutting out ribs spars trailing edge TE ailerons longerons shape length Make pattern cut out fuselage sides Cut out firewall fuselage formers cut em pennage pieces shape may glue pieces appropriate units point Wings Before beginning wing construc Over-the-shoulder view cockpit pilot sits removable 1/16-in aircraft ply cockpit cover has covered black MonoKote instrument bezels small sections brass tubing cut epox led place windshield trimmed white striping tape Access servos fuel tank through cockpit opening iJer Medermaus sitting its custom-made Pvt cradle atop what appears rather elab orate field box foldup legs complete built-in electrical fueling connections der fledermaus PAUL DENSON - BRLSA CPP STRIPS BRLSR RIBS 4 LITE PLY BRLSF1 ShEET SHEET BRLR K N AK -4 N K BPLSR 4 DO WEtS // P SKEfT C I- . -o C - - A--0 7. - BPL3P SHEET I6 SQSPRUCE LONGERONS SQ SPLEP ___ 41 x P DOUBLER N465H5Er BRLSR 36-4 MLS8rE DOWEL 6PLY LRMINRTED U Xs BRLSR WE BRRCE Zk ISHEEL N -7/I / N N V SIG STOCK 76 BRLSR 3IIEET 20-Z5 SIZE ENGINE 2-STROKE %x J-PESTOCA B615R 2- WbIEEL 0 0 0 tion have decision make want three- four-channel control Der Fledermaus designed aileron train er will fly beautifully rudder/elevator control really want build three-channel think might want convert later build aileron version ailerons lock place center wing pushrods meet wing built flat four sections will joined later put polyhedral As far know idea installing Sig symmetrical leading edge LE stock angle flat-bottomed wings originated Doc Mathews My0-My works great Thanks Doc Begin construction section pin ning bottom A-in-sq spruce spar plans use waxed paper Saran wrap tween plan structure Using ribs spacers pin x %-in TB stock plan Insert ribs except two cen ter ribs two dihedral joint ribs Glue top spar LB place stalling LE sure maintain /6-in overlap top bottom allow fit ting LE sheeting Install /6 x A-in TE fillers four wing panels installing ailerons outboard panels pin TB filler stock will become ailerons position through TB Use no glue center line Sand TB fair tapered TB filler Some photos show triangular fillets between TB ribs found us ing cap strips rendered fillets unneces sary four panels structurally com plete its time join polyhe dral unit Leave inboard panel pinned building board prop up out board panel measure 1 /2 board surface wing tip Check di hedral joint fit sand correct bevel Bpoxy A6 ply spar TB dihe dral braces place making sure main tain correct angle alignment curing Dont glue TB filler butt joints Fit glue dihedral joint ribs place same procedure applies other board outboard wing panels Assemble two wing halves pinning inboard panel building board propping up other measure inch board surface polyhe dral joint Sand upper lower spars leading trailing edge butts snug fit Double-check alignment gle pin spars LB TB butts place glue together cured clamp spar TB ply dihedral braces 28 Model Aviation installed K&B 20 Sportster engine Care fully align position engine mount before final drilling mounting make sure muffler doesnt contact fu selage After engine installed bot tom front sheeting can put place An inverted view partially finished engine compartment showing engine mount %2-in nose wheel assembly nose wheel steering pushrod throttle control cable place Note entire engine compartment has thoroughly fuel-proofed partially finished nose section beveled instrument panel has braced former Fl front side cowl panels place Note blind nuts back firewall strong triangular bracing top paneling goes after fuel tank installed Make sure provision made removing fuel tank through cockpit opening servo compartment looking aft three servos accessed through re movable ply cockpit deck receiver tightly wrapped foam installed ward crosswise throttle servo el evator rudder pushrods place Bottom view servos looking through wing mount opening plywood servo rails wing hold-down anchors visible shot wing anchors drilled tapped 1/420 nylon wing bolts leading edge wing held place us ing -in dowel socket arrangement place making sure dont protrude above below upper lower spars Once youre satisfied fit epoxy braces place Cut fit vertical-grain webbing glue place Trim /16 x 2-in balsa inboard out board TE sheeting top bottom rear turtledeck made up A-in dowels run between formers F2A F5 top formers F3 F4 I/ balsa filler pieces between dowels sanded arc Dremel tool sanding drum cut width glued place finished 3/,-in sheet tail assembly plans call cross-grained caps tne tin rudder thwart warping soft balsa fillet between stabilizer fin shown pinned place final shaping fillet tail surfaces should covered before assembly sure carefully remove covering material bonding surfaces May 1990 29 shot partially finished nose section shows fuel tank installed Note fuel tubing also place temporarily joined keep dust out tubes tank length epoxy place Mark line outboard TE sheeting show separate aileron Glue two center wing No ribs toA SIG LE STOCK SRXAA K--- _8 76--4y4- BING ------ ---------- o B L IT F IIRPLV DIHEDRAL LBRIr BALSABRACES IPIRSATRALSA C HA SUEt WINS Li_ I_ -------j---- LA DIREDRA BRACE TEDIHEDRALIIRPLY BRACE PD LV U E DR COWL SIDE IB BALSA TI/ROT TLE 3/lB SU V BA LSA I3/lB SOBALSA PB BALSAFIREWALL F II/APLY I/R PLY 0BLERRS B.20 SPOOTATER IBDI/4RALSACI DABBO BARFl TANKBATTERY BALSACYB 3IRBACSA DOUBLERWIOBIIbBBDARSBDBABE 3/lB BALSA ZYASRREEL2gether dry cut fit glue place Add /16 x 2A -in balsa upper LE sheeting gluing snugly LE spar Install bottom LE sheeting add bottom center sheeting Install IA ribs positioning ac cordance size servo Cut fit %2 ply servo mount between ribs Set wing aside until later Fuselage Make right left fuselage side A-in sheet balsa Add /6 spruce longerons wing cradle doublers vertical /8 x /16 braces aft wing position Mark lines inner sur faces sides formers firewall Lay right side over plan side view Install former Fl F2 checking verti cal alignment Remove structure side view place over top view wing attachment point facing down Glue left side place using masking tape pins hold position until glue sets Bring aft ends together over center line glue clamp until dry Drill holes firewall fuel lines throttle pushrod nose wheel block pushrod Install blind mounting nuts Install firewall fuselage epoxy using padded clamps until its dry Remember firewall must installed will provide 3D downthrust engine Glue side-to-side cross braces A/I B BA LA YR BALSA CA 30 Model Aviation Above Its easier build wing kitting first ribs top cut using up per plywood template ensure uniformity rib butted against trailing edge block middle spar notches may cut uniformly bottom template used make identical wing tips %-in balsa Below Close-up structur ally complete wing showing some details plywood landing gear mount ail eron pushrod Short pieces inner Gold-NRod sleeves inserted rib giv ing exceedingly smooth pushrod movement Above aileron pushrod between ail eron horn belicrank passes through rectangular hole sheet balsa cover ing support gussets seen photo shown plans cap strips ribs obviate necessity Below bellcrank installed its plywood mount pushrods attached bellcrank Z-bends aileron hinged very near top surface see plan Full-Size Plans AvailableSee Page 202 N I/IsSoEETIso ____ SAi----I-I--TI nrnI/IRPLY DIgEDRAL BRACED3/NROPT ML RIND 3/30 BALDA IIRP U RIREDRAL BRACEDDOUBLER RIRD ACRANNEL WIND IIII IAIAjfl 3/RU I/ARALDA YE O/IRAII/A TAPERED YE OTOCOzs' n--zz- - -- DIHED AL BRACE EDIACORAL PLY LANDING DEAR MOUNT B PLY LAMINATED WINOORIELD P3PAPD IN DO DPRUCE3/WSOBALSA I/B DOWELO PZAPA I/B ELD BRAISA FILL BALDA PILL 3/IN DO DPRRCE LONDERONO EDA I/N OUT BALSA SPAWN FOR CLARITY NYLON332 OUT BALDA 3/IR 00 BALSA /4A II2PLY DYANOARD RrB RIBO 3EA 3/32 A AIR PLY RIBS ZA RIB IA 3/3D BALSA 3/ IN SR T NALDA CUTAWAY FOB RADDER TAN L D 23~ topside formers keep strument panel correct angle y6-sq stringer installed between panel former Fl turtledeck aft cockpit made -in hardwood dowels glued between formers F2A F5 atop F3 F4 spaces between dowels next F2A filled A-in sheet balsa can cupped -in drum sander Dremel tool prior fitting Using pattern plans cut two sides front cowl A-in sheet balsa pattern should make bit oversize compensate double bevel Bevel bottom edges fit snug ly atop main longeron side panels glue place Sand top sur face sanding board making top main longerons Cover top cowl 346 cross grained sheet balsa center firewall forward cowl fashioned -in sheet balsa grain run ning lengthwise Sand top surface cowl achieve pleasing curve strument panel forward nose Cut opening cowl forward firewall accommodate engine tend use see plans opening should just wide enough allow engine slide slightly tilted engine will straightened out once bolting flanges have slipped inside fit engine engine mount insert mount bottom set engine mount Raise mount en gine high enough install muffler lower until muffler just clears top cowl locate mark engine mount holes Drill holes install blind nuts attach mount installed engine mount prematurely ended up having cut away /8 cowl surface Thats what call plan ning ahead Finally install wing hold-down blocks Empennage havent done already cut empennage surfaces /l6 sheet balsa After sanding surfaces smooth rounding edges install hinges recommend newer Sig hinges May 1990 31 DOWEL B SO WEL DER FLEDERMAUS I MODZR LOW WIND 3-ACRANNEL SPORT PLMNE DESIGNED & DRAWN NY PAUL P DENSON Left The 1A-in landing gear wire inserted slot plywood fabricated mount see construction drawing plans gear secured metal landing gear straps 1/4 x 1/wln balsa crosspiece behind gear added securing covering side opening Right servo puabrods have Du-Bro threaded couplers soldered inner ends pin has cut away vane left clevis other clvis holds system together plywood servo platform drilled ready receive servo case can glue place drop CyA cyanoacylate First glue hinges stationary surfaces cover surfac es glue movable surfaces hinges Other construction finish wing stall landing gear mounts ailerons control linkage /16 x A-in cap strips %-in balsa wing tips Cover ing very last operation landing gear shown plan made up laminating /8-in aircraft ply 10-in strip should long enough both mounts vertical supports opt commercial mount notches wings will have altered top bottom views photos plans should clarify structure Mount bellcranks between ribs 7 8 crossmember supports bellcrank /8-in Lite Ply cemented top Y6-sq balsa strips attached rib aileron pushrods connect servo bellcranks fabricated length /16 brazing rod music wire Form Z-bend outboard ends fit threaded couplers inboard ends pushrods ailerons made exactly same way Z-bend middle Dont solder threaded cou plers pntil control linkage installed checked correct alignment free movement aileron pushrods make straight run through polyhedral wings servo bellcranks originate near bottom wing servo pass through rib progressively higher point through nearly top rib No 6 polyhedral break Inner Golden Rod cut /2-in lengths glued ribs ensures free movement reduces vibration An easy way connect two devises servo cutting pin vane clevis overlaps other remaining pin used lock both devises servo see photos Use metal devises opt system Cover top wing center section add %-in balsa wing tips havent done already cut ailerons away TE outboard wing panels Bevel aileron leading edges hinge stall Install adjust pushrods between aileron horns belicranks Install pushrods fuselage After throttle nose wheel pushrods stalled engine cowling can finished sheet block balsa Drill hole A-in hold-down dowel center wing LE stall wing seated its cradle mark position dowel hole bottom former Fl Drill hole bit oversize Using cross-grained balsa strips same width wing-seating tape seat wing Carefully measure wing tip center fuselage tail end Square wing fuselage making sure two measurements identical Drill hole through wing TE wing hold-down block No 9 bit 32 Model Aviation finished tail sections ready hinging covering Installation sections cut 3A6-in sheet balsa tab fin Installed through narrow slot stabilizer completed aileron servo installation Futaba 9-28 servo mounted its case screwed servo platform Inner two ribs have slots cut away ai low up-and-down movement pushrod ELECTRIC CITABRIA great stand-way-ott scale fun ship designed 05/0 75 electric power take-offs aerobatics touch goes classic beauty yet enjoy docile slow flight easy landings Quick easy build kit includes pre cut fuselage sides tail feathers small parts step-by-step instructions complete rolled plans hardware threaded rods formed landing gear spruce spars shear webs 32 oz flying weight lightweight equipment 40 SPAN 275 SQ IN AREA FLAT BOTTOM WING 40 EJNIEQ1IEI& Electra-Combo includes kit DSC 075 Hyper thrust motor fused switch harness Tamiya style connector propeller adaptor 8/4 fiberglass propeller SPECIAL COMBO PRICE $5795 BASIC KIT $2995 IIAVEY YSTEMS675 Tower Lane West Chester PA 19380 qORPORATION 215 430-8645 thread block 4-20 tap Check threads 4-20 nylon bolt apply drop CyA both wing block holes retap Ream out wing hole A-in diameter Drill 4-in-dia hole center /2-in strip 2-in-long %2 ply Place strip over end wing holddown dowel forward side former Fl epoxy place Remove wing before epoxy sets up Cover bottom tank compart ment fuselage bottom back wing tail Sand entire struc ture smooth thoroughly clean surfac es Cover fuselage install foam wing-seating tape Carefully fuel-proof engine compartment before installing en gine engine Ive tried Der Fleder maus K&B 20 Sportster However 20-size two-cycle engine will work just well dont recommend fourcycle installation However 26 05 Surpass would probably work fine al though center-of-gravity would have adjusted compensate extra weight As rule wings airplanes size remain place since plane will fit almost automobile disassembly Radio gear access therefore primarily through cockpit cockpit cover made /16 ply has hold-down lip forward edge secured two screws fitted aft end use Futaba Conquest AM FP-T6NLK transmitter four S-38 servos mounted flat wing other three radio compartment cause no structural interference clearance adequate Flying Right beginning no doubt airplane would fly polyhedral wing stability its middle name Though ailerons hooked up just safe side discovered Der Fledermaus flies quite well rudder elevator Youll need use ai lerons rolls howeverthe polyhedral wing configuration just too much over come ailerons model rolls quite nicely serious doubts whether Der Fledermaus capable flying inverted its flat-bottomed polyhedral wing lieve first attempt fly verted able circle field three times wheels pointed skyward model will fly basic maneu vers leisurely pace Landings solid down down no bouncing airplane hugs runway present Im flying Der Fledermaus 34 rudder deflection right left elevator moves /2 up down high rate 4 low rate high rate ailerons move up % down % low rate move up % down 4 fly plane low rate time Continued page 154 May 1990 33 great companion very popular 40 Fly Baby 0 Mere Fun SPECIFICATIONS Wing Span62Y2 inches Wing Area770 square inches Engine Size10 cc 90 120 four stroke Designed forAMA FAI Turn-around pattern Foam wing stab 3-32 Balsa sheet covering Tricycle conven tional gear fixed retracts Rear side exhaust fiber glass canopy Veiy positive maneuverable XLT designed tuned pipe re tract landing gears Capable AMA Turn-around pattern Rear side ex haust SPECIFICATIONS Wing Span Wing Area Engine Size 63'a inches 700 square inches 50-60 Glow 90 four stroke fun sport pattern turn-around can done Utter Chaos completely built up Balsa construction Canopy engine mount included years proven flying reliablity BRIDI AIRCRAFT DESIGNS INC 23625 Pineforest Lane Harbor City California 90710 213 549-8264 326-5013 SEE YOUR FAVORITE HOBBY SHOP OR RETAIL OUTLETW Dealer Inquries Invited THE FIRST PRECISION-ENGINEERED ENGINE MOUNT THAT PROVIDES VIBRATION-DAMPING SOFT MOUNTING USA WITHOUT EXCESSIVE ENGINE SHAKE AT LOW RPM soft mounting excessive engine shake low RPM due damped nonlinear force-displacement characteristics ot mounting system Vibration mounts loaded compression shear Thrustforces cant causetension failures Constructed aluminum oil resistant elastomer Safety featureunique mount design captures engine airframe Light weightless standard aluminum hard mount Allows lighter front end construction Radial beam mounta available 40-65 7011 12-18 cu sizes hardware complete installation instructions included 60-day no-riak money-back guarantee direct orders Radial Meuaf $ 21w 4065 size hlp, 70-1 1 siZe $2495 121959 $2995 offwaie10319 Pine Pass Drive Houston DOAu~1 / ssOciates Vpz M2st,C4d COOS 95oopted Dwkp i oiirs tcoo LZA~MLttntsLJ ejow o , Safety/Preston Continued page 22 tors power tools nor Dremel back 1981 have either belt sander table saw might want check motor accumulated sawdust necessary vacuum out time read column hibernate during winter will about ready return flying field equipment going function just way did last year Maybe some servicing might order Meanwhile Have safe month Der Fledermaus/Denson Continued page 33 radio doesnt have dual rates set control surface movements somewhere between high low settings indicated above Differential movement aile rons necessary rock-stable trainer will bring much building flying fun its given Specifications Wingspan55/a wing chord9 wing area524 sq wing loading 166 oz/sq ft Elevator span20 elevator chord 5% avg elevator areai 15 sq Fin/rudder height36 width5 Fuselage length36 radio compart ment9 long 2/2 high 2 tn wide Recommended engine sizes20-25 twostroke 26 four-stroke Fuel tank6 oz Landing geartricycle Radio channelsthree four ailerons elevator rudder throttle Weight ready fly3 lb 60 oz Parts list Six /6 x 3 x 36-in balsa sheets wing sheeting Three %2 x 3 x 36-in balsa sheets wing ribs fuselage bottom Three / x 3 x 36-in balsa sheets front decking aft turtledeck formers fuse lage sides Two /t6 x 3 x 36-in balsa sheets rud der fin elevator fuselage bottom Four Y6-sq x 36-in spruce sticks fu selage longerons Four 3/6-sq x 36-in spruce sticks wing spars Two pieces % x 3/4 x 36-in Sig LE stock wing LE Two pieces % x x 36-in tapered balsa stock wing TE filler Two % x x 36-in balsa sticks wing TE spars 8-in-long length %-in triangular stock firewall doubler piece /16 aircraft ply wing dihedral braces piece A-in Lite Ply fuse lage formers bellcrank supports wings piece A-in aircraft ply doubleformer Fl piece %2 aircraft ply servo doubler wing piece A-in aircraft ply tATtlES MILLS METALS BOOKS PRECISOON INSTRUMENTS COMPLETE CATALOG $200 11000 r Ste. 0 4VPIISLDMJ Spron4t,ld 0I,o 45525 513 3229562 154 Model Aviation Bann Meunt 51 70-119 956w 1218 saIw Wing pan65 inches Length65 inches Wing Area845 square inches Recommended Engine Size10 cc 90 120 four stroke _________ STARLITE ST FLIGHT TRAINUW9 -13 WIJG SMN HAIO-LAIMOIED GUCEU 45y TC mAL FERI TO FLY tSsft FLK2BI5 COMPLETE CETAUD B PAGE MANUAL BALSA & HAIDWOCO 0T1 $595 beaadd*596taaI .* JAMMAESO P0 Ba I7 AtIadic4 23303 cal 1804 8240514 pisaw ad 5250 pingdalw nq,nsa kasd 1 WE BUILD YOUR HELl TEST YOUR HELl ~\REPAIRYOURHELI 322 North 7th St 61$ 4? 1 Lehighton Pa 18235 WRITE OR CALL FOR INFORMA TION firewall A-in-dia x 36-in-long length hardwood doweling turtledeck 4-in-dia x 3-in-long piece hard wood doweling wing hold-down length /g x 36-in-long music wire landing gear %2-in front landing gear assembly accessories Two 2/2-in wheels main landing gear 2-in wheel nose gear 6-oz Du-Bro equivalent fuel tank Assorted nuts bolts machine screws sheet metal screws devises threaded con nectors pushrod ends /16 brazing rod music wire /s-20 nyon wing hold-down bolts Gold-N-Rod pushrods 20- 25 two-stroke engine Appropriate glues fillers covering ma terials sundry items merchan dise may have forgotten include Radio Technique/Myers Continued page 35 pins voltages 48 four cells 60 five cells 72 six cells 84 seven cells 96 eight cells 108 nine cells Again label confusing because plug position actually refers number cells battery Actual cutoff takes place lower voltage probably take account voltage drops around circuit could otherwise cause cutoff happen too high voltage An LED light-emitting diodeRMcM display reports battery capacity cutoff percentage capacity selected discharge-current plug display actually measures elapsed time during discharge adequate cause discharge current held constant al ways use stopwatch performing battery discharge tests because elapsed time reli able indication performance piercing whistle signals end dis charge activity device does enter other mode after discharging terminates Testing unit Fast-charge testing ran several tests device notes typical test procedure charging function results follow Number cells/capacity battery 6 x 1000 mAh VDD-protected time-limited constant-current fast charger Charge current plug position 900 mA Charge/Efficiency switch position Charge under 84 VDC Measured charge current 11 mps DC 5A scale 5% analog ammeter Measured charge cutoff volts 840 DC 35-digit 1% digital voltmeter Measured trickle current pulsed DC 200 mA peak 20% cycle Time reach whistle 840 VDC 60 minutes integral timer [Notes Battery cool Doing discharge test point shows 80% charge 2 Press ing Stars button again point will stop whistle restart charging process] Time second whistle 921 VDC 14 addi tional minutes VDD cutoff INote Battery still cool Elapsed charging time about right full charge] piercing whistle signals end charge activity fast charging terminated charger drops trickle-charge mode Discharge testing As fast-charge section Multi Charge-A-Matic ran sev eral tests discharge function notes typical test procedure discharge function results follow Voltage-cutoff constant-current 2C dis chargerContinued page 158 May 1990 155 WIREMASTERm bendenlcoiler rho extra large handle bends 1/8-1/4 coils Si 32-3/16 music wire Wire creep eliminated ur ANTI-KREEP WIRE LOCK1 free catalog also has hardware accessories JOM COMPANY 114 WashIngton Terr Dept Waukegan IL 60066 Bob Fiorenze1 Hobby Center Inc Dealer Yellow Aircraft us Orders Shipped Daily_______ Now Available Fastcover covering Material Visit Oar Showroow 135 win frow Disney WorIdijJ NEW Castow Building Service 420 West SR 43414071327 6353 Winter Springs FL 32706 LW Fax 14071327-7148

NO OCR TEXT NO OCR TEXT Der Fledermaus sitting half-mile-long concrete runway available Conoors i-lying Club Luke AFB Arizona flat-bottomed polyhedral wing quite apparent angle model very stable wing configuration making great low-wing trainer cockpit Der Fledermaus tail-dragger its gear wings Though borrowed German name Fledermaus intended Scale Stand-off Scale model full-size ship Its lines similar original aircraft identical Der Fledermaus has 9-in airfoil dermaus its bare bones sanded ready covering Construction straightfor ward should present no difficulty decide build three- channel control think might want go four-channel future its best build ailerons lock place Modifying finished wing add ailerons linkage would difficult 26 Model Aviation author holding latest creation lie re ports model has excellent flight char acteristics performs standard ma neuvers stable flies inverted aspect ratio approximately 61 giving wingspan around 57 inches actually used 54-in span making panel 27 inches neatly divided nine 3-in wing bays Three-inch rib spacing allows vertical webbing cut stock balsa Also 26-in-wide MonoKote leaves narrow 2-in section center wing may covered contrast ing color used other design parameters gleaned Chuck Cunningham Ro mey Bukolt articles published past issues various hobby magazines Construction materials list included article Collect necessary materials kit plane first cutting out ribs spars trailing edge TE ailerons longerons shape length Make pattern cut out fuselage sides Cut out firewall fuselage formers cut em pennage pieces shape may glue pieces appropriate units point Wings Before beginning wing construc Over-the-shoulder view cockpit pilot sits removable 1/16-in aircraft ply cockpit cover has covered black MonoKote instrument bezels small sections brass tubing cut epox led place windshield trimmed white striping tape Access servos fuel tank through cockpit opening iJer Medermaus sitting its custom-made Pvt cradle atop what appears rather elab orate field box foldup legs complete built-in electrical fueling connections der fledermaus PAUL DENSON - BRLSA CPP STRIPS BRLSR RIBS 4 LITE PLY BRLSF1 ShEET SHEET BRLR K N AK -4 N K BPLSR 4 DO WEtS // P SKEfT C I- . -o C - - A--0 7. - BPL3P SHEET I6 SQSPRUCE LONGERONS SQ SPLEP ___ 41 x P DOUBLER N465H5Er BRLSR 36-4 MLS8rE DOWEL 6PLY LRMINRTED U Xs BRLSR WE BRRCE Zk ISHEEL N -7/I / N N V SIG STOCK 76 BRLSR 3IIEET 20-Z5 SIZE ENGINE 2-STROKE %x J-PESTOCA B615R 2- WbIEEL 0 0 0 tion have decision make want three- four-channel control Der Fledermaus designed aileron train er will fly beautifully rudder/elevator control really want build three-channel think might want convert later build aileron version ailerons lock place center wing pushrods meet wing built flat four sections will joined later put polyhedral As far know idea installing Sig symmetrical leading edge LE stock angle flat-bottomed wings originated Doc Mathews My0-My works great Thanks Doc Begin construction section pin ning bottom A-in-sq spruce spar plans use waxed paper Saran wrap tween plan structure Using ribs spacers pin x %-in TB stock plan Insert ribs except two cen ter ribs two dihedral joint ribs Glue top spar LB place stalling LE sure maintain /6-in overlap top bottom allow fit ting LE sheeting Install /6 x A-in TE fillers four wing panels installing ailerons outboard panels pin TB filler stock will become ailerons position through TB Use no glue center line Sand TB fair tapered TB filler Some photos show triangular fillets between TB ribs found us ing cap strips rendered fillets unneces sary four panels structurally com plete its time join polyhe dral unit Leave inboard panel pinned building board prop up out board panel measure 1 /2 board surface wing tip Check di hedral joint fit sand correct bevel Bpoxy A6 ply spar TB dihe dral braces place making sure main tain correct angle alignment curing Dont glue TB filler butt joints Fit glue dihedral joint ribs place same procedure applies other board outboard wing panels Assemble two wing halves pinning inboard panel building board propping up other measure inch board surface polyhe dral joint Sand upper lower spars leading trailing edge butts snug fit Double-check alignment gle pin spars LB TB butts place glue together cured clamp spar TB ply dihedral braces 28 Model Aviation installed K&B 20 Sportster engine Care fully align position engine mount before final drilling mounting make sure muffler doesnt contact fu selage After engine installed bot tom front sheeting can put place An inverted view partially finished engine compartment showing engine mount %2-in nose wheel assembly nose wheel steering pushrod throttle control cable place Note entire engine compartment has thoroughly fuel-proofed partially finished nose section beveled instrument panel has braced former Fl front side cowl panels place Note blind nuts back firewall strong triangular bracing top paneling goes after fuel tank installed Make sure provision made removing fuel tank through cockpit opening servo compartment looking aft three servos accessed through re movable ply cockpit deck receiver tightly wrapped foam installed ward crosswise throttle servo el evator rudder pushrods place Bottom view servos looking through wing mount opening plywood servo rails wing hold-down anchors visible shot wing anchors drilled tapped 1/420 nylon wing bolts leading edge wing held place us ing -in dowel socket arrangement place making sure dont protrude above below upper lower spars Once youre satisfied fit epoxy braces place Cut fit vertical-grain webbing glue place Trim /16 x 2-in balsa inboard out board TE sheeting top bottom rear turtledeck made up A-in dowels run between formers F2A F5 top formers F3 F4 I/ balsa filler pieces between dowels sanded arc Dremel tool sanding drum cut width glued place finished 3/,-in sheet tail assembly plans call cross-grained caps tne tin rudder thwart warping soft balsa fillet between stabilizer fin shown pinned place final shaping fillet tail surfaces should covered before assembly sure carefully remove covering material bonding surfaces May 1990 29 shot partially finished nose section shows fuel tank installed Note fuel tubing also place temporarily joined keep dust out tubes tank length epoxy place Mark line outboard TE sheeting show separate aileron Glue two center wing No ribs toA SIG LE STOCK SRXAA K--- _8 76--4y4- BING ------ ---------- o B L IT F IIRPLV DIHEDRAL LBRIr BALSABRACES IPIRSATRALSA C HA SUEt WINS Li_ I_ -------j---- LA DIREDRA BRACE TEDIHEDRALIIRPLY BRACE PD LV U E DR COWL SIDE IB BALSA TI/ROT TLE 3/lB SU V BA LSA I3/lB SOBALSA PB BALSAFIREWALL F II/APLY I/R PLY 0BLERRS B.20 SPOOTATER IBDI/4RALSACI DABBO BARFl TANKBATTERY BALSACYB 3IRBACSA DOUBLERWIOBIIbBBDARSBDBABE 3/lB BALSA ZYASRREEL2gether dry cut fit glue place Add /16 x 2A -in balsa upper LE sheeting gluing snugly LE spar Install bottom LE sheeting add bottom center sheeting Install IA ribs positioning ac cordance size servo Cut fit %2 ply servo mount between ribs Set wing aside until later Fuselage Make right left fuselage side A-in sheet balsa Add /6 spruce longerons wing cradle doublers vertical /8 x /16 braces aft wing position Mark lines inner sur faces sides formers firewall Lay right side over plan side view Install former Fl F2 checking verti cal alignment Remove structure side view place over top view wing attachment point facing down Glue left side place using masking tape pins hold position until glue sets Bring aft ends together over center line glue clamp until dry Drill holes firewall fuel lines throttle pushrod nose wheel block pushrod Install blind mounting nuts Install firewall fuselage epoxy using padded clamps until its dry Remember firewall must installed will provide 3D downthrust engine Glue side-to-side cross braces A/I B BA LA YR BALSA CA 30 Model Aviation Above Its easier build wing kitting first ribs top cut using up per plywood template ensure uniformity rib butted against trailing edge block middle spar notches may cut uniformly bottom template used make identical wing tips %-in balsa Below Close-up structur ally complete wing showing some details plywood landing gear mount ail eron pushrod Short pieces inner Gold-NRod sleeves inserted rib giv ing exceedingly smooth pushrod movement Above aileron pushrod between ail eron horn belicrank passes through rectangular hole sheet balsa cover ing support gussets seen photo shown plans cap strips ribs obviate necessity Below bellcrank installed its plywood mount pushrods attached bellcrank Z-bends aileron hinged very near top surface see plan Full-Size Plans AvailableSee Page 202 N I/IsSoEETIso ____ SAi----I-I--TI nrnI/IRPLY DIgEDRAL BRACED3/NROPT ML RIND 3/30 BALDA IIRP U RIREDRAL BRACEDDOUBLER RIRD ACRANNEL WIND IIII IAIAjfl 3/RU I/ARALDA YE O/IRAII/A TAPERED YE OTOCOzs' n--zz- - -- DIHED AL BRACE EDIACORAL PLY LANDING DEAR MOUNT B PLY LAMINATED WINOORIELD P3PAPD IN DO DPRUCE3/WSOBALSA I/B DOWELO PZAPA I/B ELD BRAISA FILL BALDA PILL 3/IN DO DPRRCE LONDERONO EDA I/N OUT BALSA SPAWN FOR CLARITY NYLON332 OUT BALDA 3/IR 00 BALSA /4A II2PLY DYANOARD RrB RIBO 3EA 3/32 A AIR PLY RIBS ZA RIB IA 3/3D BALSA 3/ IN SR T NALDA CUTAWAY FOB RADDER TAN L D 23~ topside formers keep strument panel correct angle y6-sq stringer installed between panel former Fl turtledeck aft cockpit made -in hardwood dowels glued between formers F2A F5 atop F3 F4 spaces between dowels next F2A filled A-in sheet balsa can cupped -in drum sander Dremel tool prior fitting Using pattern plans cut two sides front cowl A-in sheet balsa pattern should make bit oversize compensate double bevel Bevel bottom edges fit snug ly atop main longeron side panels glue place Sand top sur face sanding board making top main longerons Cover top cowl 346 cross grained sheet balsa center firewall forward cowl fashioned -in sheet balsa grain run ning lengthwise Sand top surface cowl achieve pleasing curve strument panel forward nose Cut opening cowl forward firewall accommodate engine tend use see plans opening should just wide enough allow engine slide slightly tilted engine will straightened out once bolting flanges have slipped inside fit engine engine mount insert mount bottom set engine mount Raise mount en gine high enough install muffler lower until muffler just clears top cowl locate mark engine mount holes Drill holes install blind nuts attach mount installed engine mount prematurely ended up having cut away /8 cowl surface Thats what call plan ning ahead Finally install wing hold-down blocks Empennage havent done already cut empennage surfaces /l6 sheet balsa After sanding surfaces smooth rounding edges install hinges recommend newer Sig hinges May 1990 31 DOWEL B SO WEL DER FLEDERMAUS I MODZR LOW WIND 3-ACRANNEL SPORT PLMNE DESIGNED & DRAWN NY PAUL P DENSON Left The 1A-in landing gear wire inserted slot plywood fabricated mount see construction drawing plans gear secured metal landing gear straps 1/4 x 1/wln balsa crosspiece behind gear added securing covering side opening Right servo puabrods have Du-Bro threaded couplers soldered inner ends pin has cut away vane left clevis other clvis holds system together plywood servo platform drilled ready receive servo case can glue place drop CyA cyanoacylate First glue hinges stationary surfaces cover surfac es glue movable surfaces hinges Other construction finish wing stall landing gear mounts ailerons control linkage /16 x A-in cap strips %-in balsa wing tips Cover ing very last operation landing gear shown plan made up laminating /8-in aircraft ply 10-in strip should long enough both mounts vertical supports opt commercial mount notches wings will have altered top bottom views photos plans should clarify structure Mount bellcranks between ribs 7 8 crossmember supports bellcrank /8-in Lite Ply cemented top Y6-sq balsa strips attached rib aileron pushrods connect servo bellcranks fabricated length /16 brazing rod music wire Form Z-bend outboard ends fit threaded couplers inboard ends pushrods ailerons made exactly same way Z-bend middle Dont solder threaded cou plers pntil control linkage installed checked correct alignment free movement aileron pushrods make straight run through polyhedral wings servo bellcranks originate near bottom wing servo pass through rib progressively higher point through nearly top rib No 6 polyhedral break Inner Golden Rod cut /2-in lengths glued ribs ensures free movement reduces vibration An easy way connect two devises servo cutting pin vane clevis overlaps other remaining pin used lock both devises servo see photos Use metal devises opt system Cover top wing center section add %-in balsa wing tips havent done already cut ailerons away TE outboard wing panels Bevel aileron leading edges hinge stall Install adjust pushrods between aileron horns belicranks Install pushrods fuselage After throttle nose wheel pushrods stalled engine cowling can finished sheet block balsa Drill hole A-in hold-down dowel center wing LE stall wing seated its cradle mark position dowel hole bottom former Fl Drill hole bit oversize Using cross-grained balsa strips same width wing-seating tape seat wing Carefully measure wing tip center fuselage tail end Square wing fuselage making sure two measurements identical Drill hole through wing TE wing hold-down block No 9 bit 32 Model Aviation finished tail sections ready hinging covering Installation sections cut 3A6-in sheet balsa tab fin Installed through narrow slot stabilizer completed aileron servo installation Futaba 9-28 servo mounted its case screwed servo platform Inner two ribs have slots cut away ai low up-and-down movement pushrod ELECTRIC CITABRIA great stand-way-ott scale fun ship designed 05/0 75 electric power take-offs aerobatics touch goes classic beauty yet enjoy docile slow flight easy landings Quick easy build kit includes pre cut fuselage sides tail feathers small parts step-by-step instructions complete rolled plans hardware threaded rods formed landing gear spruce spars shear webs 32 oz flying weight lightweight equipment 40 SPAN 275 SQ IN AREA FLAT BOTTOM WING 40 EJNIEQ1IEI& Electra-Combo includes kit DSC 075 Hyper thrust motor fused switch harness Tamiya style connector propeller adaptor 8/4 fiberglass propeller SPECIAL COMBO PRICE $5795 BASIC KIT $2995 IIAVEY YSTEMS675 Tower Lane West Chester PA 19380 qORPORATION 215 430-8645 thread block 4-20 tap Check threads 4-20 nylon bolt apply drop CyA both wing block holes retap Ream out wing hole A-in diameter Drill 4-in-dia hole center /2-in strip 2-in-long %2 ply Place strip over end wing holddown dowel forward side former Fl epoxy place Remove wing before epoxy sets up Cover bottom tank compart ment fuselage bottom back wing tail Sand entire struc ture smooth thoroughly clean surfac es Cover fuselage install foam wing-seating tape Carefully fuel-proof engine compartment before installing en gine engine Ive tried Der Fleder maus K&B 20 Sportster However 20-size two-cycle engine will work just well dont recommend fourcycle installation However 26 05 Surpass would probably work fine al though center-of-gravity would have adjusted compensate extra weight As rule wings airplanes size remain place since plane will fit almost automobile disassembly Radio gear access therefore primarily through cockpit cockpit cover made /16 ply has hold-down lip forward edge secured two screws fitted aft end use Futaba Conquest AM FP-T6NLK transmitter four S-38 servos mounted flat wing other three radio compartment cause no structural interference clearance adequate Flying Right beginning no doubt airplane would fly polyhedral wing stability its middle name Though ailerons hooked up just safe side discovered Der Fledermaus flies quite well rudder elevator Youll need use ai lerons rolls howeverthe polyhedral wing configuration just too much over come ailerons model rolls quite nicely serious doubts whether Der Fledermaus capable flying inverted its flat-bottomed polyhedral wing lieve first attempt fly verted able circle field three times wheels pointed skyward model will fly basic maneu vers leisurely pace Landings solid down down no bouncing airplane hugs runway present Im flying Der Fledermaus 34 rudder deflection right left elevator moves /2 up down high rate 4 low rate high rate ailerons move up % down % low rate move up % down 4 fly plane low rate time Continued page 154 May 1990 33 great companion very popular 40 Fly Baby 0 Mere Fun SPECIFICATIONS Wing Span62Y2 inches Wing Area770 square inches Engine Size10 cc 90 120 four stroke Designed forAMA FAI Turn-around pattern Foam wing stab 3-32 Balsa sheet covering Tricycle conven tional gear fixed retracts Rear side exhaust fiber glass canopy Veiy positive maneuverable XLT designed tuned pipe re tract landing gears Capable AMA Turn-around pattern Rear side ex haust SPECIFICATIONS Wing Span Wing Area Engine Size 63'a inches 700 square inches 50-60 Glow 90 four stroke fun sport pattern turn-around can done Utter Chaos completely built up Balsa construction Canopy engine mount included years proven flying reliablity BRIDI AIRCRAFT DESIGNS INC 23625 Pineforest Lane Harbor City California 90710 213 549-8264 326-5013 SEE YOUR FAVORITE HOBBY SHOP OR RETAIL OUTLETW Dealer Inquries Invited THE FIRST PRECISION-ENGINEERED ENGINE MOUNT THAT PROVIDES VIBRATION-DAMPING SOFT MOUNTING USA WITHOUT EXCESSIVE ENGINE SHAKE AT LOW RPM soft mounting excessive engine shake low RPM due damped nonlinear force-displacement characteristics ot mounting system Vibration mounts loaded compression shear Thrustforces cant causetension failures Constructed aluminum oil resistant elastomer Safety featureunique mount design captures engine airframe Light weightless standard aluminum hard mount Allows lighter front end construction Radial beam mounta available 40-65 7011 12-18 cu sizes hardware complete installation instructions included 60-day no-riak money-back guarantee direct orders Radial Meuaf $ 21w 4065 size hlp, 70-1 1 siZe $2495 121959 $2995 offwaie10319 Pine Pass Drive Houston DOAu~1 / ssOciates Vpz M2st,C4d COOS 95oopted Dwkp i oiirs tcoo LZA~MLttntsLJ ejow o , Safety/Preston Continued page 22 tors power tools nor Dremel back 1981 have either belt sander table saw might want check motor accumulated sawdust necessary vacuum out time read column hibernate during winter will about ready return flying field equipment going function just way did last year Maybe some servicing might order Meanwhile Have safe month Der Fledermaus/Denson Continued page 33 radio doesnt have dual rates set control surface movements somewhere between high low settings indicated above Differential movement aile rons necessary rock-stable trainer will bring much building flying fun its given Specifications Wingspan55/a wing chord9 wing area524 sq wing loading 166 oz/sq ft Elevator span20 elevator chord 5% avg elevator areai 15 sq Fin/rudder height36 width5 Fuselage length36 radio compart ment9 long 2/2 high 2 tn wide Recommended engine sizes20-25 twostroke 26 four-stroke Fuel tank6 oz Landing geartricycle Radio channelsthree four ailerons elevator rudder throttle Weight ready fly3 lb 60 oz Parts list Six /6 x 3 x 36-in balsa sheets wing sheeting Three %2 x 3 x 36-in balsa sheets wing ribs fuselage bottom Three / x 3 x 36-in balsa sheets front decking aft turtledeck formers fuse lage sides Two /t6 x 3 x 36-in balsa sheets rud der fin elevator fuselage bottom Four Y6-sq x 36-in spruce sticks fu selage longerons Four 3/6-sq x 36-in spruce sticks wing spars Two pieces % x 3/4 x 36-in Sig LE stock wing LE Two pieces % x x 36-in tapered balsa stock wing TE filler Two % x x 36-in balsa sticks wing TE spars 8-in-long length %-in triangular stock firewall doubler piece /16 aircraft ply wing dihedral braces piece A-in Lite Ply fuse lage formers bellcrank supports wings piece A-in aircraft ply doubleformer Fl piece %2 aircraft ply servo doubler wing piece A-in aircraft ply tATtlES MILLS METALS BOOKS PRECISOON INSTRUMENTS COMPLETE CATALOG $200 11000 r Ste. 0 4VPIISLDMJ Spron4t,ld 0I,o 45525 513 3229562 154 Model Aviation Bann Meunt 51 70-119 956w 1218 saIw Wing pan65 inches Length65 inches Wing Area845 square inches Recommended Engine Size10 cc 90 120 four stroke _________ STARLITE ST FLIGHT TRAINUW9 -13 WIJG SMN HAIO-LAIMOIED GUCEU 45y TC mAL FERI TO FLY tSsft FLK2BI5 COMPLETE CETAUD B PAGE MANUAL BALSA & HAIDWOCO 0T1 $595 beaadd*596taaI .* JAMMAESO P0 Ba I7 AtIadic4 23303 cal 1804 8240514 pisaw ad 5250 pingdalw nq,nsa kasd 1 WE BUILD YOUR HELl TEST YOUR HELl ~\REPAIRYOURHELI 322 North 7th St 61$ 4? 1 Lehighton Pa 18235 WRITE OR CALL FOR INFORMA TION firewall A-in-dia x 36-in-long length hardwood doweling turtledeck 4-in-dia x 3-in-long piece hard wood doweling wing hold-down length /g x 36-in-long music wire landing gear %2-in front landing gear assembly accessories Two 2/2-in wheels main landing gear 2-in wheel nose gear 6-oz Du-Bro equivalent fuel tank Assorted nuts bolts machine screws sheet metal screws devises threaded con nectors pushrod ends /16 brazing rod music wire /s-20 nyon wing hold-down bolts Gold-N-Rod pushrods 20- 25 two-stroke engine Appropriate glues fillers covering ma terials sundry items merchan dise may have forgotten include Radio Technique/Myers Continued page 35 pins voltages 48 four cells 60 five cells 72 six cells 84 seven cells 96 eight cells 108 nine cells Again label confusing because plug position actually refers number cells battery Actual cutoff takes place lower voltage probably take account voltage drops around circuit could otherwise cause cutoff happen too high voltage An LED light-emitting diodeRMcM display reports battery capacity cutoff percentage capacity selected discharge-current plug display actually measures elapsed time during discharge adequate cause discharge current held constant al ways use stopwatch performing battery discharge tests because elapsed time reli able indication performance piercing whistle signals end dis charge activity device does enter other mode after discharging terminates Testing unit Fast-charge testing ran several tests device notes typical test procedure charging function results follow Number cells/capacity battery 6 x 1000 mAh VDD-protected time-limited constant-current fast charger Charge current plug position 900 mA Charge/Efficiency switch position Charge under 84 VDC Measured charge current 11 mps DC 5A scale 5% analog ammeter Measured charge cutoff volts 840 DC 35-digit 1% digital voltmeter Measured trickle current pulsed DC 200 mA peak 20% cycle Time reach whistle 840 VDC 60 minutes integral timer [Notes Battery cool Doing discharge test point shows 80% charge 2 Press ing Stars button again point will stop whistle restart charging process] Time second whistle 921 VDC 14 addi tional minutes VDD cutoff INote Battery still cool Elapsed charging time about right full charge] piercing whistle signals end charge activity fast charging terminated charger drops trickle-charge mode Discharge testing As fast-charge section Multi Charge-A-Matic ran sev eral tests discharge function notes typical test procedure discharge function results follow Voltage-cutoff constant-current 2C dis chargerContinued page 158 May 1990 155 WIREMASTERm bendenlcoiler rho extra large handle bends 1/8-1/4 coils Si 32-3/16 music wire Wire creep eliminated ur ANTI-KREEP WIRE LOCK1 free catalog also has hardware accessories JOM COMPANY 114 WashIngton Terr Dept Waukegan IL 60066 Bob Fiorenze1 Hobby Center Inc Dealer Yellow Aircraft us Orders Shipped Daily_______ Now Available Fastcover covering Material Visit Oar Showroow 135 win frow Disney WorIdijJ NEW Castow Building Service 420 West SR 43414071327 6353 Winter Springs FL 32706 LW Fax 14071327-7148

NO OCR TEXT NO OCR TEXT Der Fledermaus sitting half-mile-long concrete runway available Conoors i-lying Club Luke AFB Arizona flat-bottomed polyhedral wing quite apparent angle model very stable wing configuration making great low-wing trainer cockpit Der Fledermaus tail-dragger its gear wings Though borrowed German name Fledermaus intended Scale Stand-off Scale model full-size ship Its lines similar original aircraft identical Der Fledermaus has 9-in airfoil dermaus its bare bones sanded ready covering Construction straightfor ward should present no difficulty decide build three- channel control think might want go four-channel future its best build ailerons lock place Modifying finished wing add ailerons linkage would difficult 26 Model Aviation author holding latest creation lie re ports model has excellent flight char acteristics performs standard ma neuvers stable flies inverted aspect ratio approximately 61 giving wingspan around 57 inches actually used 54-in span making panel 27 inches neatly divided nine 3-in wing bays Three-inch rib spacing allows vertical webbing cut stock balsa Also 26-in-wide MonoKote leaves narrow 2-in section center wing may covered contrast ing color used other design parameters gleaned Chuck Cunningham Ro mey Bukolt articles published past issues various hobby magazines Construction materials list included article Collect necessary materials kit plane first cutting out ribs spars trailing edge TE ailerons longerons shape length Make pattern cut out fuselage sides Cut out firewall fuselage formers cut em pennage pieces shape may glue pieces appropriate units point Wings Before beginning wing construc Over-the-shoulder view cockpit pilot sits removable 1/16-in aircraft ply cockpit cover has covered black MonoKote instrument bezels small sections brass tubing cut epox led place windshield trimmed white striping tape Access servos fuel tank through cockpit opening iJer Medermaus sitting its custom-made Pvt cradle atop what appears rather elab orate field box foldup legs complete built-in electrical fueling connections der fledermaus PAUL DENSON - BRLSA CPP STRIPS BRLSR RIBS 4 LITE PLY BRLSF1 ShEET SHEET BRLR K N AK -4 N K BPLSR 4 DO WEtS // P SKEfT C I- . -o C - - A--0 7. - BPL3P SHEET I6 SQSPRUCE LONGERONS SQ SPLEP ___ 41 x P DOUBLER N465H5Er BRLSR 36-4 MLS8rE DOWEL 6PLY LRMINRTED U Xs BRLSR WE BRRCE Zk ISHEEL N -7/I / N N V SIG STOCK 76 BRLSR 3IIEET 20-Z5 SIZE ENGINE 2-STROKE %x J-PESTOCA B615R 2- WbIEEL 0 0 0 tion have decision make want three- four-channel control Der Fledermaus designed aileron train er will fly beautifully rudder/elevator control really want build three-channel think might want convert later build aileron version ailerons lock place center wing pushrods meet wing built flat four sections will joined later put polyhedral As far know idea installing Sig symmetrical leading edge LE stock angle flat-bottomed wings originated Doc Mathews My0-My works great Thanks Doc Begin construction section pin ning bottom A-in-sq spruce spar plans use waxed paper Saran wrap tween plan structure Using ribs spacers pin x %-in TB stock plan Insert ribs except two cen ter ribs two dihedral joint ribs Glue top spar LB place stalling LE sure maintain /6-in overlap top bottom allow fit ting LE sheeting Install /6 x A-in TE fillers four wing panels installing ailerons outboard panels pin TB filler stock will become ailerons position through TB Use no glue center line Sand TB fair tapered TB filler Some photos show triangular fillets between TB ribs found us ing cap strips rendered fillets unneces sary four panels structurally com plete its time join polyhe dral unit Leave inboard panel pinned building board prop up out board panel measure 1 /2 board surface wing tip Check di hedral joint fit sand correct bevel Bpoxy A6 ply spar TB dihe dral braces place making sure main tain correct angle alignment curing Dont glue TB filler butt joints Fit glue dihedral joint ribs place same procedure applies other board outboard wing panels Assemble two wing halves pinning inboard panel building board propping up other measure inch board surface polyhe dral joint Sand upper lower spars leading trailing edge butts snug fit Double-check alignment gle pin spars LB TB butts place glue together cured clamp spar TB ply dihedral braces 28 Model Aviation installed K&B 20 Sportster engine Care fully align position engine mount before final drilling mounting make sure muffler doesnt contact fu selage After engine installed bot tom front sheeting can put place An inverted view partially finished engine compartment showing engine mount %2-in nose wheel assembly nose wheel steering pushrod throttle control cable place Note entire engine compartment has thoroughly fuel-proofed partially finished nose section beveled instrument panel has braced former Fl front side cowl panels place Note blind nuts back firewall strong triangular bracing top paneling goes after fuel tank installed Make sure provision made removing fuel tank through cockpit opening servo compartment looking aft three servos accessed through re movable ply cockpit deck receiver tightly wrapped foam installed ward crosswise throttle servo el evator rudder pushrods place Bottom view servos looking through wing mount opening plywood servo rails wing hold-down anchors visible shot wing anchors drilled tapped 1/420 nylon wing bolts leading edge wing held place us ing -in dowel socket arrangement place making sure dont protrude above below upper lower spars Once youre satisfied fit epoxy braces place Cut fit vertical-grain webbing glue place Trim /16 x 2-in balsa inboard out board TE sheeting top bottom rear turtledeck made up A-in dowels run between formers F2A F5 top formers F3 F4 I/ balsa filler pieces between dowels sanded arc Dremel tool sanding drum cut width glued place finished 3/,-in sheet tail assembly plans call cross-grained caps tne tin rudder thwart warping soft balsa fillet between stabilizer fin shown pinned place final shaping fillet tail surfaces should covered before assembly sure carefully remove covering material bonding surfaces May 1990 29 shot partially finished nose section shows fuel tank installed Note fuel tubing also place temporarily joined keep dust out tubes tank length epoxy place Mark line outboard TE sheeting show separate aileron Glue two center wing No ribs toA SIG LE STOCK SRXAA K--- _8 76--4y4- BING ------ ---------- o B L IT F IIRPLV DIHEDRAL LBRIr BALSABRACES IPIRSATRALSA C HA SUEt WINS Li_ I_ -------j---- LA DIREDRA BRACE TEDIHEDRALIIRPLY BRACE PD LV U E DR COWL SIDE IB BALSA TI/ROT TLE 3/lB SU V BA LSA I3/lB SOBALSA PB BALSAFIREWALL F II/APLY I/R PLY 0BLERRS B.20 SPOOTATER IBDI/4RALSACI DABBO BARFl TANKBATTERY BALSACYB 3IRBACSA DOUBLERWIOBIIbBBDARSBDBABE 3/lB BALSA ZYASRREEL2gether dry cut fit glue place Add /16 x 2A -in balsa upper LE sheeting gluing snugly LE spar Install bottom LE sheeting add bottom center sheeting Install IA ribs positioning ac cordance size servo Cut fit %2 ply servo mount between ribs Set wing aside until later Fuselage Make right left fuselage side A-in sheet balsa Add /6 spruce longerons wing cradle doublers vertical /8 x /16 braces aft wing position Mark lines inner sur faces sides formers firewall Lay right side over plan side view Install former Fl F2 checking verti cal alignment Remove structure side view place over top view wing attachment point facing down Glue left side place using masking tape pins hold position until glue sets Bring aft ends together over center line glue clamp until dry Drill holes firewall fuel lines throttle pushrod nose wheel block pushrod Install blind mounting nuts Install firewall fuselage epoxy using padded clamps until its dry Remember firewall must installed will provide 3D downthrust engine Glue side-to-side cross braces A/I B BA LA YR BALSA CA 30 Model Aviation Above Its easier build wing kitting first ribs top cut using up per plywood template ensure uniformity rib butted against trailing edge block middle spar notches may cut uniformly bottom template used make identical wing tips %-in balsa Below Close-up structur ally complete wing showing some details plywood landing gear mount ail eron pushrod Short pieces inner Gold-NRod sleeves inserted rib giv ing exceedingly smooth pushrod movement Above aileron pushrod between ail eron horn belicrank passes through rectangular hole sheet balsa cover ing support gussets seen photo shown plans cap strips ribs obviate necessity Below bellcrank installed its plywood mount pushrods attached bellcrank Z-bends aileron hinged very near top surface see plan Full-Size Plans AvailableSee Page 202 N I/IsSoEETIso ____ SAi----I-I--TI nrnI/IRPLY DIgEDRAL BRACED3/NROPT ML RIND 3/30 BALDA IIRP U RIREDRAL BRACEDDOUBLER RIRD ACRANNEL WIND IIII IAIAjfl 3/RU I/ARALDA YE O/IRAII/A TAPERED YE OTOCOzs' n--zz- - -- DIHED AL BRACE EDIACORAL PLY LANDING DEAR MOUNT B PLY LAMINATED WINOORIELD P3PAPD IN DO DPRUCE3/WSOBALSA I/B DOWELO PZAPA I/B ELD BRAISA FILL BALDA PILL 3/IN DO DPRRCE LONDERONO EDA I/N OUT BALSA SPAWN FOR CLARITY NYLON332 OUT BALDA 3/IR 00 BALSA /4A II2PLY DYANOARD RrB RIBO 3EA 3/32 A AIR PLY RIBS ZA RIB IA 3/3D BALSA 3/ IN SR T NALDA CUTAWAY FOB RADDER TAN L D 23~ topside formers keep strument panel correct angle y6-sq stringer installed between panel former Fl turtledeck aft cockpit made -in hardwood dowels glued between formers F2A F5 atop F3 F4 spaces between dowels next F2A filled A-in sheet balsa can cupped -in drum sander Dremel tool prior fitting Using pattern plans cut two sides front cowl A-in sheet balsa pattern should make bit oversize compensate double bevel Bevel bottom edges fit snug ly atop main longeron side panels glue place Sand top sur face sanding board making top main longerons Cover top cowl 346 cross grained sheet balsa center firewall forward cowl fashioned -in sheet balsa grain run ning lengthwise Sand top surface cowl achieve pleasing curve strument panel forward nose Cut opening cowl forward firewall accommodate engine tend use see plans opening should just wide enough allow engine slide slightly tilted engine will straightened out once bolting flanges have slipped inside fit engine engine mount insert mount bottom set engine mount Raise mount en gine high enough install muffler lower until muffler just clears top cowl locate mark engine mount holes Drill holes install blind nuts attach mount installed engine mount prematurely ended up having cut away /8 cowl surface Thats what call plan ning ahead Finally install wing hold-down blocks Empennage havent done already cut empennage surfaces /l6 sheet balsa After sanding surfaces smooth rounding edges install hinges recommend newer Sig hinges May 1990 31 DOWEL B SO WEL DER FLEDERMAUS I MODZR LOW WIND 3-ACRANNEL SPORT PLMNE DESIGNED & DRAWN NY PAUL P DENSON Left The 1A-in landing gear wire inserted slot plywood fabricated mount see construction drawing plans gear secured metal landing gear straps 1/4 x 1/wln balsa crosspiece behind gear added securing covering side opening Right servo puabrods have Du-Bro threaded couplers soldered inner ends pin has cut away vane left clevis other clvis holds system together plywood servo platform drilled ready receive servo case can glue place drop CyA cyanoacylate First glue hinges stationary surfaces cover surfac es glue movable surfaces hinges Other construction finish wing stall landing gear mounts ailerons control linkage /16 x A-in cap strips %-in balsa wing tips Cover ing very last operation landing gear shown plan made up laminating /8-in aircraft ply 10-in strip should long enough both mounts vertical supports opt commercial mount notches wings will have altered top bottom views photos plans should clarify structure Mount bellcranks between ribs 7 8 crossmember supports bellcrank /8-in Lite Ply cemented top Y6-sq balsa strips attached rib aileron pushrods connect servo bellcranks fabricated length /16 brazing rod music wire Form Z-bend outboard ends fit threaded couplers inboard ends pushrods ailerons made exactly same way Z-bend middle Dont solder threaded cou plers pntil control linkage installed checked correct alignment free movement aileron pushrods make straight run through polyhedral wings servo bellcranks originate near bottom wing servo pass through rib progressively higher point through nearly top rib No 6 polyhedral break Inner Golden Rod cut /2-in lengths glued ribs ensures free movement reduces vibration An easy way connect two devises servo cutting pin vane clevis overlaps other remaining pin used lock both devises servo see photos Use metal devises opt system Cover top wing center section add %-in balsa wing tips havent done already cut ailerons away TE outboard wing panels Bevel aileron leading edges hinge stall Install adjust pushrods between aileron horns belicranks Install pushrods fuselage After throttle nose wheel pushrods stalled engine cowling can finished sheet block balsa Drill hole A-in hold-down dowel center wing LE stall wing seated its cradle mark position dowel hole bottom former Fl Drill hole bit oversize Using cross-grained balsa strips same width wing-seating tape seat wing Carefully measure wing tip center fuselage tail end Square wing fuselage making sure two measurements identical Drill hole through wing TE wing hold-down block No 9 bit 32 Model Aviation finished tail sections ready hinging covering Installation sections cut 3A6-in sheet balsa tab fin Installed through narrow slot stabilizer completed aileron servo installation Futaba 9-28 servo mounted its case screwed servo platform Inner two ribs have slots cut away ai low up-and-down movement pushrod ELECTRIC CITABRIA great stand-way-ott scale fun ship designed 05/0 75 electric power take-offs aerobatics touch goes classic beauty yet enjoy docile slow flight easy landings Quick easy build kit includes pre cut fuselage sides tail feathers small parts step-by-step instructions complete rolled plans hardware threaded rods formed landing gear spruce spars shear webs 32 oz flying weight lightweight equipment 40 SPAN 275 SQ IN AREA FLAT BOTTOM WING 40 EJNIEQ1IEI& Electra-Combo includes kit DSC 075 Hyper thrust motor fused switch harness Tamiya style connector propeller adaptor 8/4 fiberglass propeller SPECIAL COMBO PRICE $5795 BASIC KIT $2995 IIAVEY YSTEMS675 Tower Lane West Chester PA 19380 qORPORATION 215 430-8645 thread block 4-20 tap Check threads 4-20 nylon bolt apply drop CyA both wing block holes retap Ream out wing hole A-in diameter Drill 4-in-dia hole center /2-in strip 2-in-long %2 ply Place strip over end wing holddown dowel forward side former Fl epoxy place Remove wing before epoxy sets up Cover bottom tank compart ment fuselage bottom back wing tail Sand entire struc ture smooth thoroughly clean surfac es Cover fuselage install foam wing-seating tape Carefully fuel-proof engine compartment before installing en gine engine Ive tried Der Fleder maus K&B 20 Sportster However 20-size two-cycle engine will work just well dont recommend fourcycle installation However 26 05 Surpass would probably work fine al though center-of-gravity would have adjusted compensate extra weight As rule wings airplanes size remain place since plane will fit almost automobile disassembly Radio gear access therefore primarily through cockpit cockpit cover made /16 ply has hold-down lip forward edge secured two screws fitted aft end use Futaba Conquest AM FP-T6NLK transmitter four S-38 servos mounted flat wing other three radio compartment cause no structural interference clearance adequate Flying Right beginning no doubt airplane would fly polyhedral wing stability its middle name Though ailerons hooked up just safe side discovered Der Fledermaus flies quite well rudder elevator Youll need use ai lerons rolls howeverthe polyhedral wing configuration just too much over come ailerons model rolls quite nicely serious doubts whether Der Fledermaus capable flying inverted its flat-bottomed polyhedral wing lieve first attempt fly verted able circle field three times wheels pointed skyward model will fly basic maneu vers leisurely pace Landings solid down down no bouncing airplane hugs runway present Im flying Der Fledermaus 34 rudder deflection right left elevator moves /2 up down high rate 4 low rate high rate ailerons move up % down % low rate move up % down 4 fly plane low rate time Continued page 154 May 1990 33 great companion very popular 40 Fly Baby 0 Mere Fun SPECIFICATIONS Wing Span62Y2 inches Wing Area770 square inches Engine Size10 cc 90 120 four stroke Designed forAMA FAI Turn-around pattern Foam wing stab 3-32 Balsa sheet covering Tricycle conven tional gear fixed retracts Rear side exhaust fiber glass canopy Veiy positive maneuverable XLT designed tuned pipe re tract landing gears Capable AMA Turn-around pattern Rear side ex haust SPECIFICATIONS Wing Span Wing Area Engine Size 63'a inches 700 square inches 50-60 Glow 90 four stroke fun sport pattern turn-around can done Utter Chaos completely built up Balsa construction Canopy engine mount included years proven flying reliablity BRIDI AIRCRAFT DESIGNS INC 23625 Pineforest Lane Harbor City California 90710 213 549-8264 326-5013 SEE YOUR FAVORITE HOBBY SHOP OR RETAIL OUTLETW Dealer Inquries Invited THE FIRST PRECISION-ENGINEERED ENGINE MOUNT THAT PROVIDES VIBRATION-DAMPING SOFT MOUNTING USA WITHOUT EXCESSIVE ENGINE SHAKE AT LOW RPM soft mounting excessive engine shake low RPM due damped nonlinear force-displacement characteristics ot mounting system Vibration mounts loaded compression shear Thrustforces cant causetension failures Constructed aluminum oil resistant elastomer Safety featureunique mount design captures engine airframe Light weightless standard aluminum hard mount Allows lighter front end construction Radial beam mounta available 40-65 7011 12-18 cu sizes hardware complete installation instructions included 60-day no-riak money-back guarantee direct orders Radial Meuaf $ 21w 4065 size hlp, 70-1 1 siZe $2495 121959 $2995 offwaie10319 Pine Pass Drive Houston DOAu~1 / ssOciates Vpz M2st,C4d COOS 95oopted Dwkp i oiirs tcoo LZA~MLttntsLJ ejow o , Safety/Preston Continued page 22 tors power tools nor Dremel back 1981 have either belt sander table saw might want check motor accumulated sawdust necessary vacuum out time read column hibernate during winter will about ready return flying field equipment going function just way did last year Maybe some servicing might order Meanwhile Have safe month Der Fledermaus/Denson Continued page 33 radio doesnt have dual rates set control surface movements somewhere between high low settings indicated above Differential movement aile rons necessary rock-stable trainer will bring much building flying fun its given Specifications Wingspan55/a wing chord9 wing area524 sq wing loading 166 oz/sq ft Elevator span20 elevator chord 5% avg elevator areai 15 sq Fin/rudder height36 width5 Fuselage length36 radio compart ment9 long 2/2 high 2 tn wide Recommended engine sizes20-25 twostroke 26 four-stroke Fuel tank6 oz Landing geartricycle Radio channelsthree four ailerons elevator rudder throttle Weight ready fly3 lb 60 oz Parts list Six /6 x 3 x 36-in balsa sheets wing sheeting Three %2 x 3 x 36-in balsa sheets wing ribs fuselage bottom Three / x 3 x 36-in balsa sheets front decking aft turtledeck formers fuse lage sides Two /t6 x 3 x 36-in balsa sheets rud der fin elevator fuselage bottom Four Y6-sq x 36-in spruce sticks fu selage longerons Four 3/6-sq x 36-in spruce sticks wing spars Two pieces % x 3/4 x 36-in Sig LE stock wing LE Two pieces % x x 36-in tapered balsa stock wing TE filler Two % x x 36-in balsa sticks wing TE spars 8-in-long length %-in triangular stock firewall doubler piece /16 aircraft ply wing dihedral braces piece A-in Lite Ply fuse lage formers bellcrank supports wings piece A-in aircraft ply doubleformer Fl piece %2 aircraft ply servo doubler wing piece A-in aircraft ply tATtlES MILLS METALS BOOKS PRECISOON INSTRUMENTS COMPLETE CATALOG $200 11000 r Ste. 0 4VPIISLDMJ Spron4t,ld 0I,o 45525 513 3229562 154 Model Aviation Bann Meunt 51 70-119 956w 1218 saIw Wing pan65 inches Length65 inches Wing Area845 square inches Recommended Engine Size10 cc 90 120 four stroke _________ STARLITE ST FLIGHT TRAINUW9 -13 WIJG SMN HAIO-LAIMOIED GUCEU 45y TC mAL FERI TO FLY tSsft FLK2BI5 COMPLETE CETAUD B PAGE MANUAL BALSA & HAIDWOCO 0T1 $595 beaadd*596taaI .* JAMMAESO P0 Ba I7 AtIadic4 23303 cal 1804 8240514 pisaw ad 5250 pingdalw nq,nsa kasd 1 WE BUILD YOUR HELl TEST YOUR HELl ~\REPAIRYOURHELI 322 North 7th St 61$ 4? 1 Lehighton Pa 18235 WRITE OR CALL FOR INFORMA TION firewall A-in-dia x 36-in-long length hardwood doweling turtledeck 4-in-dia x 3-in-long piece hard wood doweling wing hold-down length /g x 36-in-long music wire landing gear %2-in front landing gear assembly accessories Two 2/2-in wheels main landing gear 2-in wheel nose gear 6-oz Du-Bro equivalent fuel tank Assorted nuts bolts machine screws sheet metal screws devises threaded con nectors pushrod ends /16 brazing rod music wire /s-20 nyon wing hold-down bolts Gold-N-Rod pushrods 20- 25 two-stroke engine Appropriate glues fillers covering ma terials sundry items merchan dise may have forgotten include Radio Technique/Myers Continued page 35 pins voltages 48 four cells 60 five cells 72 six cells 84 seven cells 96 eight cells 108 nine cells Again label confusing because plug position actually refers number cells battery Actual cutoff takes place lower voltage probably take account voltage drops around circuit could otherwise cause cutoff happen too high voltage An LED light-emitting diodeRMcM display reports battery capacity cutoff percentage capacity selected discharge-current plug display actually measures elapsed time during discharge adequate cause discharge current held constant al ways use stopwatch performing battery discharge tests because elapsed time reli able indication performance piercing whistle signals end dis charge activity device does enter other mode after discharging terminates Testing unit Fast-charge testing ran several tests device notes typical test procedure charging function results follow Number cells/capacity battery 6 x 1000 mAh VDD-protected time-limited constant-current fast charger Charge current plug position 900 mA Charge/Efficiency switch position Charge under 84 VDC Measured charge current 11 mps DC 5A scale 5% analog ammeter Measured charge cutoff volts 840 DC 35-digit 1% digital voltmeter Measured trickle current pulsed DC 200 mA peak 20% cycle Time reach whistle 840 VDC 60 minutes integral timer [Notes Battery cool Doing discharge test point shows 80% charge 2 Press ing Stars button again point will stop whistle restart charging process] Time second whistle 921 VDC 14 addi tional minutes VDD cutoff INote Battery still cool Elapsed charging time about right full charge] piercing whistle signals end charge activity fast charging terminated charger drops trickle-charge mode Discharge testing As fast-charge section Multi Charge-A-Matic ran sev eral tests discharge function notes typical test procedure discharge function results follow Voltage-cutoff constant-current 2C dis chargerContinued page 158 May 1990 155 WIREMASTERm bendenlcoiler rho extra large handle bends 1/8-1/4 coils Si 32-3/16 music wire Wire creep eliminated ur ANTI-KREEP WIRE LOCK1 free catalog also has hardware accessories JOM COMPANY 114 WashIngton Terr Dept Waukegan IL 60066 Bob Fiorenze1 Hobby Center Inc Dealer Yellow Aircraft us Orders Shipped Daily_______ Now Available Fastcover covering Material Visit Oar Showroow 135 win frow Disney WorIdijJ NEW Castow Building Service 420 West SR 43414071327 6353 Winter Springs FL 32706 LW Fax 14071327-7148