Control Line: Speed

C onE rot M Speed Gene Hempel build sA pipe column next will devoted construction article written Jeny Bradshaw Sacramento CA March 14 1980 asked Jerry would willing share some valuable pipe information construction techniques After some arm twisting bunch pleases consented Last month Jerry bestowed upon fantastic construction article follows have thoroughly enjoyed working Jerry would like express appreciation him ajob very well done Soread guys Im sure will agree Hand-torm sheet aluminum blank around solid Inc smeps Ifl forming inc cone snells raper patterns inc len aluminum bianks cone Author uses X-Acto hammer plastic formed around solid conesfirst side other Note finished shell has head gently tap edge will lie flat 1/16-in overlap remains together form smooth joint match solid cone 50 Model Aviation Top bottom lathe-turned solid metal cone forms paper patterns note 1/16-in added overlap long edges 018 sheet aluminum blanks cut exact size paper patterns UCI recoy 10 oraze snell impie scneme nere IS marvellously simple third hand Grip shell needle-nose pliers use rubberbands around plier handles keep good grip shell clamp pliers vise shell joint top horizontalit keeps flux running off Objects background container wellmixed brazing flux roll brazing rod Mpply inc nux aiong Joint Pleat joint flux will change liquid white crusty build-up Build Own AA Tuned Pipe competitive Speed advan tageous use tuned pipe Unfortunately pipes homebuilt ones sharing construction techniques hope help encourage modelers build own tuned pipes pipe design article exact used establish Speed record 12011 mph 1974 construction tech niques can used build size pipe fact Luther Roy used techniques make pipe used set new FAI Speed record 16029 mph Editors note record has subsequently bettered Charles Lieber 16221 mph ABMeM Pipe material Select purest aluminum parts will give best braze will also soft easier form Avoid 2000 7000 series aluminum very difficult braze cones made 1100 H sheet aluminum 0018-in thick pipe adaptor headpipe end headpipe made 6061-T4 aluminum headpipe 5/16-in ID Ys-in od aluminum tubing tailpipe 7/32-in ID -in OD aluminum tubing available hobby shops local surplus store good source other aluminum Brazing material brazing wire flux used can purchased Sears Craftsman No 718 aluminum brazing wire 1/16-in diameter No33 aluminum brazing flux two items come twin-pack numbered 80994 Heat source use regular Bernzomatic torch heat uses propane gas fuel brazing use pencil-flame burner unit model JT 681 CAUTION*CAUTION*CAUTION propane torch such Bernzomatic can produce heat high 1400 degrees Fahrenheit Keep work area clear flammable items Pipe design pipe design shown arrived after much trial error Although design has proven very effective no means ultimate experimenting different lengths angles may pleasant ly surprised find additional power purpose article show tuned pipe can constructed using very basic tools intent cover resonant expansion chamber theory design very good source information found TwoStroke Tuners Handbook Gordon Jennings Bill Wisniewskis article Model Airplane News March 1967 another excellent source Before construction techniques pre sented detail want very honest say brazing aluminum easy task roughly 50-degree spread between melt ing brazing rod melting sheet alumi num tricky job have become familiar much heat use remove flame can done little practice Give try Construction techniques lathe turn two metal wood cones exact size inside dimensions front rear cones next step make paper pattern cone Roll piece paper around cone edge paper forms center line end end cone paper draw line around ends cone another line down center Allow 1/16-in overlap joint Cut piece sheet aluminum same size pattern Repeat same steps other cone use Scotch Brite clean pieces wash soap water use steel wool clean metal tiny particles could remain contaminate Continued page 12U April1981 51 eriur IUA will dJdl1 turn liqujo As rod starts melt move flame rod down joint Use great careIts over flux will flow down cone solidify look messy 5Ohotter aluminum shell will meltLet cone cool scrub off flux soap watereasy forms Two metal conesthe exact size inside dimension front rear cones youre going make M ~ iflcations Th i mm 111111ca 1245 81 jfl-____ IlliIIIIi liii 111111 IIHIL1111111 III IIIWeight 12 Engine 91 line drixe unit 1 eperate detachahi presheeted wing panels 2 lreassemhiled fuselage frame 1 lreassemhiled stabilizer clevators vertical fin rudderU L 4 Epuxy Glass cnwl wheelpants 5 Furmed hatch clear canupy Wayne Ulerys outstanding design Leo Loudenslagers Laser 200 geared 90 offered Model Merchant nearly constructed model critical fuselage & control surfaces framing wing sheeting has done Just some finish up ready fly best available 6 Aluminum landing gear 554 E Fronton SI Brownsville TX 78520 Features * MOST STREAMLINED * COOL RUNNING * COMPUTED FOR YOUR ENGINE * NOTHING TO ADJUST * NO STRAPS NT FALL OFF * TAPPED FOR MUFFLER PRESSURE * LIGHT WEIGHT. 19 - 46 size approx 3/4 oz 50 90 size approx 1-1/2 oz * PROVEN IN NATIONAL COMPETITION LOWEST POWER LOSS PRICE $2000 POSTAGE & HANDLING 0 OHIO RESIDENTS ADOL SALES TAX 0 K & B 40 BAFFLE ADAPTERS AVAILABLE . AND STILL NO UNSIGHTLY STRAPS ONLY $200 ADDITIONAL ROBERT PAUL PREPAID CHECK OR 1462 ORCHARD GROVE MONEY ORDER TO LAKEWOOD OHIO 44107 US clear followed further wet sanding No 400 paper Nationals next day let plane sit two weeks wet-sand using No 600 paper Finally ready rubbing compound Start red compound white use Turtle Wax liquid rubbing compound plane should now ready very light coat wax wantOr use long tedious proccess neces sary top finish airplane worked Gene has worked very similar operations just about everybody wants beautiful finish Stunt plane information stunt PAMPA write Wynn Paul 1640 MaywickDit Lexington KY 40504 CL Carrier/Perry Continued page 49 models CL model Dave claims really improves low-speed handling downthrust airfoil result experiments model variable thrust line removable wings variety configura tions could tried common problem among Carrier models classes engine goes rich lean air must set too lean too rich ground get good run air probability getting good setting first time out low such model suction systems lean ground setting will often cause loss power takeoff Uniflow tank venting used Stunt models has single vent tube ending near fuel pickup tube tank supplies fuel under constant pressure pickup tube Under flight condi tions however pressure carburetor can vary considerably variation pressure thus fuel mixture caused acceleration lateral inboard/outboard positioning tank vent either atmospheric pressure crankcase pressure determines effect centrifugal acceleration fuel supply engine vent inboard carburetor centrifugal acceleration will increase fuel pressure carb speed increases vent outboard carb engine will go leaner speed increases effects reduced pressure systems just same model accelerates takeoff fuel pressure reduced greater distance end vent carb greater effect No would expect suction engine keep running peak speed ifthe fuel tank suddenly moved foot below engine effect takeoff acceleration Profile Carrier engine standard uniflow tank published details Profile Carrier fuel tanks few years ago primary feature uniflow vent location front tank have used type tank success no means adjusting vent location except putting spacers under tank accompanying drawing shows tank can fine-tuned get exactly engine response desired movable vent initially should set about 34-in inboard left side looking forward side tank use needle valve would set maximum engine rpm opened until first drop engine speed occurs setting can found consis tently avoids too-lean mixture takeoff Fly model note in-flight mixtureit will probably rich engine rich flight move vent tube out about i-in time until flight mixture optimum sure keep tank filled during process Once best setting found vent can soldered place final note pump-equipped engines subject same acceleration problems can draw fuel location output pressure constant An engine pump backplate must mounted cylinder vertical side-mounted will go rich flightperhaps too much compensated lean ground setting RichardL Perry 416 WoodhiliDrive Golds boro NC 27530 CL Speed/Hempel Continued page 51 joint Next form sheet aluminum around solid cone Start edge using fingers bend metal Work slowly dont crease metal use X-Acto hammer plastic head gently tap edge will lie flat match solid cone other edge same way Roll cone flat surface sheet metal will conform solid cone shape metal must overlap 1/16-in remain together have smooth joint Brazing cones Remove solid cone sheet aluminum cone must held horizontally joint top prevent flux running off Both hands needed brazing hold torch apply brazing rod Use pair needle-nose pliers hold cone Wrap rubberband around handles keep pliers closed Clamp pliers vise braze use flux right tube will get lot liquid few crystals crystals important part flux empty tube flux small bottle mix thoroughly brazing rod Use same rod apply flux along joint Light torch adjust center blue flame extends /4 5/16-in nozzle Apply heat along joint flux will change liquid white crusty buildup Now move heat small end cone As temperature increases flux will tum back liquid look like water Dip rod bottle flux put joint As rod starts melt move flame rod down joint dont remain spoi longer necessary Watch heat 120 Model Aviation DEALER S DISTRIRUTOR INQUIRIES INVifED 5121 541-3867 Engines Parts Accessories Service FOX AIRCRAFT ENGINES throttle #11500 FOX 15 Baffle Piston$ 2495 #11600 FOX 15 Schnuerle-Bushing 95 #11698 FOX l5Schnuerle 2 BB4995 #11900 FOX 193195 #12500 FOX 253195 #13500 FOX 35 Stunt3195 #13799 FOX Combat Special MK-IV 365995 FOX AIRCRAFT ENGINES throttle #21600 FOX l5Schnuerle-Bushing 21698 FOX l5Schnuerle 2DB #21 900 FOX 19 Bushing #22500 FOX 25 Bushing #23899 FOX 36RX w/Muffler5995 #24000 FOX 40 Bushing-Schnuerle 6495 #24100 FOX 40 BB Schnuerle7995 #24500 FOX 45 Bushing-Schnuerle 6495 #24000 FOX 45 BB-Schnuerle7995 #26099 FOX EAGLE7995 #26299 FOX EAGLE II Rear Exhaust12500 #21 200 FOX TWIN 120cc Short Disc 25000 5995 4195 4195 THE FOX 45 BBRC MARK-X CARBURETORS #24051 MK-X Fox 40 45$ #26051 MK-X B Fox 60 Eagle Twin #261 51 MKX C Robart Pumper #26251 MK-X 0 Tuned Pipe 50 Series Fox 19 & 25 Line 501 646-1656 F G CO 5305 TOWSON AVE FORT SMITH ARK 72901 After cone cools clean cone soap water remove flux Repeat pro cedures other cone Thats month guys rest article will appear next Speed column Meanwhile suggest practice Jerrys brazing technique described above critical difficult technique used construct ing Jerrys pipe blades have noticed flier has problems engine runs competition According tests fuel content has big effect long engine runs per tank oil nitro added fuel mixture running time proportionately shortened contrary 2% benzene unleaded gasoline added running time lengthened approximately 5% Stilomags first flight went very well lead-out adjustment center its range -oz outboard wing tip weight added models control response quite good went through its paces usually fly 015-in braided lines 65-ft long future flights will 018-in feel will slightly improve control response Gene Hempel 301 N Yale Dr Garland TX 75042 Stilomag Fernandez Continued page 54 stiffened 1/32 plywood sheet inside both weigh fter filling sanding completed entire model covered Japanese tissue model primed spray-painted several coats paint varnish followed up paste-waxing finished model weighs between 53 54 ounces paint scheme used designed give good refereiice points maneuvers engine its modified exhaust prac tically noiselessyet strong enough give fine account itself props homemade 11 x 6s large HNDRTODN~ 9 0 2 /4 YOLJI. INPOOR 4AtJD-AUJLWV W FROM TYRO MODELS RAYRIflrFMllCFl SPECIFICATIONS Wing Span 485 n Overall Length. Wing Chord 0 n Mn Oeq Wgr Wing Arne og o Engino Srzn g-Og Price $2895 yoor Hobby Onalnt ordering direct please add $2 5Otor5reight handling&inoarance Caligornra reordents odd 6% Salon Tao Manofactorod Tyro Models Thet ore Desryned Fly! StlI Aoel et $4805 PLAYBOY SENI mr t S hendireg -OR53t gh Fast realistic aerobatic kit features ABS wheelpants moulded canopy pre-bent wire Send $2500 plus $500 shipping TLC R/C PRODUCTS Rt 1 Box 282 Prospect VA 23901 P0 Box 3957 Torrance CA 90510 April 1981 121 2495 2495 2495 2495 1995 1iO L.. DR PO BOX 11511 LT2A9o641s6-7781 RUBBER STRIP FAI RUBBER 4 out S flyaff 1979 World Championships used FAI RUBBER Made USA SIZES Y 3/76 1/8 3/32 1/76 1mm 042 thick SPOOLED GROSS WT 1-4 7-V2 LBS PRICE $7250 first spool PPD US Additional spools $7250 NEW PIRELLI SIZES 6mm 5mm 4mm X 1mm PRICE $1500 first hank PPD US Additionalspools $1450 Sole US Distributor World-Wide Sales Send 25 cents 1980 Catalog FAI Model Supply a