Align Your Front End

JkpYour Frontfd simple jig makes straight strong front end lot easier achieve jig takes about two hours build costs about eight dollars can adapted types enginepowered model air planes UT Michael Jennings EACH MODEL builder tackles con struction airplane different way Theres no single best method some techniques better others arti cle describes better job plan ning building front end air craft through use simple engine tank mounting jig exception Gliders Elec trics airplane needs engine/fuel tank assembly regardless construc tion method used An easy-on easy-off en gine/tank mounting assembly thats light weight straight strong makes bet ter performing efficient model thats easier handle maintainand much fun fly jig represents proven method easily building such structure airplane As building projects paper work must done first examples shown feature inverted engine installa tion techniques upright installa other drawings engine installed inverted An upright engine installation however would involve same procedures described text Note cutout tank rests maintains critical relationship between tank centerline needle valve required smooth en gine run whether flying upright Inverted tion same key variable vertical distance between engine needle valve centerline fuel tank center line coincide case Though engine profile isnt critical needs reasonably accurate dis tance between mounting bolt face spinner backplate critical engine photo has spacer installed drawing shows modification engine bolt pattern Jig Its fancy its easy build its effective different jig needed different engines course jig assures perfect bolt align ment completed front end assembly similar engine runs both level verted flight should expected pre fer lean out engine inverted flight consider installing fuel tank % 66 Model Aviation basic dimensions engine used measured sketched Mylar drafting film critical feature view mounting bolt pattern layout relationship between mounting bolt centerline needle valve must also taken careful consideration Left partially disassembled jig showing its parts Its important pine board forming base flat Above two parallel lines base board critical must absolutely true multiple parallel cross lines aligning front bulkhead above centerline aircraft verted fuel tank will below en gine causing lean out Once youve found good engine fuel tank combination stick Let experts tinkering well flying Construction Draw layouts Mylar drafting film Mylar rather expensive about four dol lars 24 x 36-in sheet Its very stable durable however well worth extra expense Youll need about three square feet material can purchased nearly engineering graphics paper supply company Cut sheet smaller ones needed first drawing shows two views engine bolted directly spinner assemblythe side profile bottom view Make both views using engine set calipers 6-in scale mea sure engines critical features addition make view engine bearers location engine mounting bolt holes CL Precision Aer obatics aircraft holes should have three-degree offset depending de sign youre using what youve found work case optimum three-degree right offset engine bearer view used lay out hole loca tions maple bearers placing Mylar drawing directly over bearer Laying out opposite offset actually quite easy just take time make sure its right next drawing profile en gine A-in extension between en gine spinner assembly use exten sion models except cant fitted allows extra 1/2 between needle valve propel ler Extensions cause front engine bear ing wear faster can replace en gine bearing easily finger last drawing shows fuel tank ma ple engine bearers mounting plate bulkheads A-in aluminum mounting plate slips between engine bearer distribute engine bolt load across wood bearer surface views could made single sheet Mylar However drawing separate sheets gives flexibility overlaying plans allows examine slightly different combina tions due different front end geometries front end design also allows re move engine removing fuel tank visa versa greatly reduces time takes make swaps during con tests shouldnt take 10 min utes make swap design cowl course major consideration next step build engine bolt pat tern jig jig will assure engine bolts predrilled mounting holes engine bearers Its made piece A-in aluminum plate holes must match engine mounting lugs Fox 40 Compact Deluxe holes % x 1%-in rectangular pattern Allen head cap screws 4-40 x 1 nuts sandwich aluminum plate complete engine bolt pattern jig Two pictures show jig holds front engine assembly parts gether view disassembled other assembled purchased parts con sist two pairs two-inch inside corner braces costing about three dollars rest material scrap 1 x 6-in flat piece pine three pieces % x /2-in hard maple perhaps previous building projectContinued page 174 October 1990 67 iruni eno paris laid out ready Tilling jig two short pieces drilled holes 1/.ifl aluminum shims slip between engine bearer pre vent bolting forces crushing bearer Its easier build bulkheads flush sand flush later square resting base plank helps determine flush fit engine bearer Dont glue anything until good flush fit achieved Note engine bolt pattern jig shown place nearly finished engine/tank mounting assembly Its square strong light parallax photo makes jig appear unsquare triangular gussets have yet installed assembly set up inverted engine installation spacer spinner helps keep fingers away prop youre working needle valve author famous mustache minus Infamous cigar holding Con trol Line Precision Aerobatics Eagle calls Illegal model houses jigbuilt engine/fuel tank mounting assemblies Youll See * Flying off lake smashing ice * What happens whan hand launch forget turn radio plane * A mplane turn tree4ane * A Rocket engine mourst#to E7mdecker * Four wrecked planes turne0 Twin flewi * And just lot Bad much Dont miss ons oti Send check m 420 L phone 717342-1963 VISA-MASTE CL Aerobatics/McMiIIan Continued page 170 Ordinarily oils will work short periods time dry out couple other choices know will work Use Vaseline some Teflon powder mixed touch warm soldering iron will flow Vaseline bearing cools down will stay put its job will remain solid form normal temper atures use effective long can fly plane Ive got planes over 2000 flights credit controls still free bearings tight Use motorcycle chain lube product comes out its aerosol can foam slowly changes state become gellike have work lube bearing once will stay put CL Scale/Boss Continued page 63 terials time Dougs message should coming through loud clear pays think light build light better flying longer lasting models WarbirdsClassic American Fighters & Bomb ers title book WW II fighter bomber lovers might want add library book Michael OLeary Norman Pealing Mike Jerram compila tion work previously published Gunfighter Bombers OLeary American Warbirds Pealing Warbirds Jerram 239-page work contains over 260 extraordinary color illus trations classic American fighters bombers include P-5 1 P-40 F8F Bearcat F6F Hellcat F4F Wildcat F4U Cor sair P-47 P-38 TBM Avenger AD Skyraider B-25 A-26 PV-2 Harpoon B-26 Marauder A20 Havoc B-17 B-24 B-29 photos book excellent qual ity show much fine detail often look building models book recommended library shelf re search purposes am sure will find photos just what need color documentation purposes 1990 edi tion ISBN 0-517-01218-9 published Mili tary Press distributed Crown Publishers Inc 225 Park Ave South NY NY 10003 found copy local Barnes Noble bookstore cost $20-plus New trim sheets Eagle Products has just intro duced line fuclproof applied per structions trim sheets come four differ ent styles three-color sheet solid fluorescent colors vertical horizontal stripe sheets stripes graduated sizes threecolor sheets have colors complement other ie yellow-orange-red Cub yellowred-gray three-color sheet has large 3In center stripe 3A -in stripe either side center stripe %-in stripe alongside 4-in stripes package contains three 6-in-wide x 27in-long sheets trim sheets can cut desired shape design remove liner stick model following few simple instructions No heat other adhesives required trim sheets may have limited use Scale models am sure will great help dressing up sportflying models Prices range about $17 $23 per package depending type trim sheets specific information product its distribution write Eagle Prod ucts PO Box 4609 Covina CA 91723 tel 1818/339-1311 Caption correction July column pic ture Bill Reynolds Grumman Bearcat credited being taken C Peter Cornils credit should have read Chris Peter Cornils Chris wifes name Chris sorry error Please send ideas notice upcoming CL Scale events contest reports especially photos CL Scale activity address very top column Alignment/Jennings Continued page 67 Draw parallel lines 2% apart 1 x 6-in pine Thats width front end design Yours may different lines run full length 1 x 6-in pine plank Redraw theyre parallel rear bulkhead support fixed support front bulkhead adjustable Cut front bulkhead support fourth corner brace Cut out parts front end bulkheads made aircraft plywood Lite Ply engine bearers x -in hard maple re duce effects drill runout drill en gine mounting holes mounting side Make relief cuts fuel tank maintains relationship between nee dle valve fuel tank centerline Load parts jig trimming sanding No gluing done stage bulkheads must flush en gine bearer edges Check four corners flush fit Sand trim discrepan cies must done before gluing Install engine bolt pattern jig align space engine bearers satisfied fit remove parts jig Lay piece plastic wrap over jig Make two cuts cor ner braces bolt post allows plastic wrap lay flat prevents gluing front end assembly jig Reassem ble parts jig glue gether Use 45-minute epoxy glue joints dry remove assembly jig completed product along en gine fuel tank shown pictures Reinforce intersections assembly 1A-in triangular balsa gus sets Gussets should installed top side engine bearers Install after epoxying blind nuts Notch gussets blind nuts relieve engine mounting bolts may pass through gussets will prevent blind nuts working loose model aircraft can course built such jigs its much difficult Continued page 176 174 Model Aviation RIC FOLLIES PRESENTS Craziest Wacklest Funniest MEFAIpiea Wreeirs YouD Ever Seoul Over 30 Minutes CRASH after CRASH after CRASH iadXo vee~C ecee 93t -c ~cO5 ~j83Xe 6e pop tiorAoe Ot6S 59SC0jJ o c 0 4 Participating RCD Sticker Stations Southern Radio Control Lons WC Service Naples FLPhoenix NY 813 775-1554315 695-2448 S & 0 WC ServiceD&J ElectronicsRivergate Hobby Center San Jose CAHowell MlGoodlettsville TN 408 281-1549517 546-2644615 859-3455 Authorized WC ServiceIraft Midwest IMI Fallbrook CANorthoille Ml 619 728-0440313 348-0095 Wollitz RIC Jacksonoillo FL 904 771-0613 DoMond RIC Service Carrollton ITt 214 242-4682 Ocean County Il/C Service Toms hoer NJ 201 505-8477 Alignment/Jennings Continued page 174 make airplane straight square jig helps assure straight square front end Materials project cost about eight dollars takes about two hours build Both dollarwise timewise thats pretty low-cost insur ance comments welcome Send cards letters T M Jennings 60L1 Banbury Rd Knoxville TN 37922 AMA/NFFS Ind/Clemens Continued page 71 growing Indoor events Thanks recent pro posal Don Lindley has achieved rule book status No fewer 54 people signed up unique event 48 actually flying Among Don Lindley himself sixth-place score 5088 would have won event year earlier perhaps thanks widening use new tan rubber flight times took dramatic jump over four quarter minutes Indeed Richard Miller Bill Henderson tied first place identical 416 flights charisma ratings 815 forcing flyoff Using 42-in loop 075 tan Miller cranked 4000 turns ROGd 410 flight Hen derson Canadian entrant blew two motors try ing wind Boston Bluefish finally con ceded Miller Both used models re quired 15 x 25 x 3-in box section laid flat Cc provide partial lift format along use three- four-bladed propellers wac seen number Bostonian entries AMA Rubber Scale 14 entries nine high-wing cabin models evidence Qnl3 biplane three low-wingers th field Canadian Ken Groves surprised no b entering yet another long series well crafted Fike Dream replicas winning th event total score 183 featuring flights o 90 89 seconds 90 seconds max AMA Scale Second place went Cincinnatis Jin Miller flying Lacey M-10 Some observert noted irony having two aircraft tha long scourge Peanut Scale turn up winners AMA event Biplanes triplane four canards some low wingers other interesting models weri among 31 entered Peanut Jim Millers fine flying Voisin Hydroplane canard topped thi field followed Jack McGillivrays Isaac Fury biplane Mike CoIlings pre-WW Ble riot VII Junior-Senior class another Voi sin took first hands Don De Loach o Dallas TX No-Cal Scale calls models profile fuse lages maximum span 16 minimun weight 62 grams USIC favorite drew 2 fliers flock diverse subject matter rang ing supersonic jet fighter craft th early days aviation jet using tail mounted pusher propeller Soviet Sukhc Su-27 Flanker built flown David Aron stein Renton WA three official flight consistently put colorfully trimmed mode right up under Minidome ceiling th longest clocking 543 Flying somewhz whimsical choice Les Garber Du Continued page 1 176 Model Aviation 7rEc0VOWflI iJSTED AIVI ANYou p0t LOt en1%1 RGD L9~ AM pj1 ecte6 Ccliii .kIllLil0 bobb~pbeXo GSR Products Sacramento CA 916 362-1962 Radio South Pensacola FL 904 478-6745