Caudimordax Fast Combat smaller engines works Three ounces fuel can last up five minutes shoulder stays piece slower tight-turning ship gives edge over opponentand engine costs lot less Hlskandar Taib AMERICAN COMBAT design philosophy has traditionally favored speed over turning ability Note large sums money spent Hoffelts custom Foxes bolted onto 300- 400-sq-in airplanes weighing 21 oz What en gines share besides enormous power output weight Most weigh about 9/2 oz Caudimordax design takes other approach high rate turn small turning radius given top priority qualities achieved using light engine high aspect ratio wing compromise speed Caudimordax Brat 28 flies 10 15 mph slower level flight typical Fast Combat job makes up turns though much tighter actually slow down ship much less would heavier model Flying Fast Combat smaller engines has other advantages Three ounces fuel Left left unmodified Brat 28 stIll sporting its RC carburetor author has several give away right modified Brat 28 Note missing metal around exhaust port thinned head fins homemade venturi 7 x 6 Talpal prop Right Close-up view remote needle valve assembly unit OS 10 FSR RC used Note short length tubing slipped over end needle valve prevent leakage plastic clip fuel line available author 68 Model Aviation Author/builder Iskandar Taib holding Caudimordax thoroughly designed Combat plane gives up some top speed typically 10-15 mph makes up barely slowing corners Light weight along special modifications engine make possible Left Mark made crankshaft intake ports closing side Right Mark made opening side Note amount metal has removed Brats have very conservative timing befits its sport RC roots Left Front end tail boom Note shallow cuts made aluminum epoxy grab Small holes may drilled instead Right Engine mount assembly center rib Mount marked sawing using front center rib pattern ft Components horizontal stabilizer Start epoxying arrow shaft stab anchor Glue hinge assembly stab anchor cover horizontal stab -In medium balsa glue stab anchor Right completed tail assembly Notice hinge built String wrapped figure-eight pattern around two 3As dowels December 1990 69 F 4 4 \ - will last five minutes airplane doesnt dislocate shoulder its fast cant keep up slower tight-turning airplane can also hard opponent line up have gotten several kills other guy overshot attack Perhaps important engines cost far less bigger counterparts Caudimordax can also used Out law FAJ contests sprouting up over Midwest Rules typically specify Fast Slow rules 15 engines 52-ft lines no restrictions engine tank setups nitro content fuel Most Schnuerle-ported double ball bear ing 15s weigh about six ounces 34 oz less Brat 28 modifications needed use slightly smaller typically l/ engine bearer spacing mount engine slightly further ward Caudimordax design goes back sev eral years evolving slowly its present form admittedly incorporating features currently vogue External con trols instance now being used top fliers including Russians save much building time allowing use solid wing panels Another great time-saver simple cutout blad der tank replaces common rocket tube arrow-shaft tail boom al though requires little extra building time allows easier rebuilding saves little weight agility Caudimordax attribut able its high aspect ratio wing thick airfoil high aspect ratio reduces tip vortices cause induced drag thick airfoil delays onset high-speed stall thick airfoil also lends lateral sta FAST COMBAT DESIGN ESR 23-32 ENGINES bility design helps control snap rolling associated high aspect ratio designs Induced drag Just what induced drag its reduction important Combat design Drag generally divided two types often confused Parasitic drag caused friction air surface airplane therefore proportional surface area wing Also included category drag lines drag caused protuberances airplane such pushrod engine cylinder Streamlining serves reduce parasitic drag Induced drag other hand re lated lift produced wing wing producing lift pressure air bottom surface wing greater pressure top pressure differences cause air above wings move outward toward wing tips air below wings move toward root tips nothing pre vent air below wings curling around tips pushing down top surface wing reducing actual amount lift produced airflow around wing tip also pro duces turbulent vortices often visible va por trails emanating wing tips jet fighters during high-G maneuvers energy needed drive vortices ulti mately Linked drag drag sociated vortices de scribed induced drag greater lift 70 Model Aviation Pushrod braces made outer Sullivan Ny-Rod Filament tape wraps tail boom bed nails particular piece made out straight section chip-core board Full-Size Plans Available. Page 200 nI 1~ ** TJ / produced wing larger vor tices Several strategies exist reduction tip vortices Tip fences instance will impede air flowing around wing tips Low aspect ratio wings would benefit tip fences Ed Brzys listen ing Theyve seen full-scale air planes low aspect ratio wings such pretty Racing biplane Sorceress Hoer ner anti-vortex tips variation tip fence shaped force airflow tips counter direction tip vor tex However work air plane experiences positive Gs Flip air plane its back anti-vortex tips ac tually add problem Forward sweep wing causes air flow move toward root can spill cause vortex forward swept wings have extremely rigid withstand aeroelastic twisting forces increase wing twists technically known aeroelastic divergence Another way improve efficiency lift/drag ratio wing use smaller wing tip Wind tunnel experiments have shown Schuemann planform shouldnt called George Perryman planform currently vogue glider pi lots has least amount induced drag given amount lift elliptical planform eg Spitfire almost good wing no taper 60% 65% efficient elliptical wing same pect ratio wing tip chord 60% 65% root chord 90% 95% efficient turn tapered wing produces lot less induced drag nontapered High aspect ratio wings have smaller amounts tip spillage low aspect ratio wings less wing tip length per unit area Glider wings have high aspect ratios very purpose High aspect ratio wings have own problems however main being added bending stresses put Continued page 172 Left Cutting top surface wing core Core held tightly board embedded nalis Note bow held Right Cutting spar slot Slot cut single pass down back up Author gives complete directions foam wing cutting something rarely done December 1990 71 / 7- design drawing Nur Iskandar Taib modela fill need hotdog show-off sport plane Knife edge take-offs flat apins snaps anything can Wing foam Fuselage Tail lite ply balsa Builds quick lands like trainer Flyingweight lOlba 184 1 l3lbs 192 Ohio OHIO SUPERSTAR PRODUCTS INC 11376 RIOGEWAY ROADKENSINGTON OHIO 44427 r 216-223-1950 great idea cant resist quoting Mr Stahls comments opening paragraph Overemphasis strictly flying designs con tests throughout country recent years has brought about unwarranted condition ne glect building flying Scale semiscale models Much favoritism must tributed desire maximum performance since little need said relative appearance neatly built Scale ship usual contest design SAM Italia Dr Ferdinando Gale Baveno aly recently sent interesting handbook about Eastern bloc engines written Cesare de Robertis Well illustrated unusual model power plants text Italian available Gale Via Marconi 10 28042 Baveno NO Italy interesting material de signs emerging SAM Italia including several magnificent construction drawings beautiful Italian Gliders pre-WW II era available B2 Streamlines PO Box 976 Olalla WA 98359 RC Pylon/Hager Continued page 64 no mediocre planes event fact well done dont know pilots selected would show two three brought along would still out trying decide Id vote collection absolutely beautiful takeoff area too narrow support four planes up heats threeplane blasts Plans have made things works widen takeoff area fourplane heats can accommodated next spring top 10 finishers Saturday 1 Randy Rich 11480 2 Richard Oliver 11701 3 Red Cranfield 12189 4 Phil Bussell 11742 5 Jim Young 11859 6 Bill Hager 11539 7 Hubert Wills 11905 8 Norm Johnson 11473 9 Dub Jets 11487 10 Sam Womack 11656 Just keep everyones attention two midairs Saturday both occurring just out turn number three Poor Bob Greer par ticipant little high-speed tangos Dave Layman Bill Hager Jerry Small tried trade little paint flight wound up getting planes dirty easier transport under seat Sundays action just hot heavy make sure moves down pat Bob Greer provided present what violent midair collision since vention prop happened about 20 ft di rectly behind above head stood cage turn number pilot lane made clock locked ac tion happened felt bad pilots crash itself right out movies another midair just out turn number three tame comparison Bob Greer/Hubert Wills fiasco earlier com pletely forgot get names pilots volved Yours Truly Bill Hager Jerry SmallBH Top five finishers Sunday 1 Dub Jett 11685 2 Red Cranfield l193 Phil Bussell 12059 4 Bill Hager 11614 5 Montie Montcrief 11620 6 Clay Gary 11509 7 Dave Layman 11381 8 Norm Johnson 11415 9 Randy Ritch 11529 10 Sam Wo mack 12772 Fast time meet 11090 turned Jerry Small lot really good close tight racing action both days can per sonally vouch quality food available heard nothing praise con dition fieldits size its location think two quotes heard often Yall have best racing facilities around grass field absolutely fantastic shape nice words made feel kinda proud field proud have small part core club members come out work event got meet some super-nice guys see some beautiful planes doin some really competitive racing besides Bob Greer Ill long time talking about Sun day midair yours Take guys put first-class race the field great shape See next month Caudimordax/Taib Continued page 71 wing lift being generated farther out root Very high aspect ratio wings demand extra strength conse quently added weight spars root particular application will demand aspect ratio provides best combi nation weight efficiency Cau dimordax aspect ratio 61 cho sen allowed convenient wing span 48 inches Styrofoam comes 2-ftwide sheetsjust right wing panel mean chord eight inches al lows 10-in root 6-in tip 60% tip/root percentage Such wing core too difficult cut trailing edge swept forward three inches lead ing edge swept back inch producing net sweep quarter-chord zero Experiments straight leading edge produced airplanes unpleasant snap rolling tendencies swept leading edge also allows easier placement spars greater lead-out sweep Eliminating high-speed stall Turning airplane too tightly causes wing stall wing forced produce lift capable producing produce lift angle attack must creased Beyond certain angle attack air flow along top wing separates wings surface becomes turbu lent causing sudden increase drag Most Combat fliers adjust controls limit turn radius order avoid stal ling Another approach use thicker blunter airfoil stalls higher Us thin does drawback ap proach course thicker airfoil has greater parasitic drag top speed reduced accordingly Caudimordax root section thick 15% tip thicker 25% relatively thicker tip airfoil ensures root will stall first turn thus reduc ing airplanes tendency drop wing tip tendency causes lateral instabil ity common high aspect ratio Combat wings Longitudinal stability An airplane does tight fast turns absolutely no use cant make go want go common problem Combat wings lack longitudinal stability turn once started will tighten up its own ac cord makes airplane unpointable therefore useless Combat air plane should also able fly straight unattended An unstable airplane will tend tighten wander out turn pilot glances away inslant common misconception sta 172 Model Aviation SPORTOBATIC 2 84 For1204cycleand 902-cycle rST 200025003000-0 PS 18 NEWOS BGX 13500 bilator elevator make airplane move up down true designer could reduce stabilator area airplane thats overly sensitive unstable Actually opposite true stabilator provides stability opposing downward pitching moment produced wing larger stabilizer larger airplanes stability margin since stabilizer doesnt have work hard Similarly longer tail moment increases stability providing longer moment arm stabilizer act Spitfire airplane too small horizontal stabilizer earlier marks had very small acceptable range CG center-of-gravity ad ditional equipment added aft ac ceptable range aircrafts stability de creased fact several structural failures traced directly aircraft tight ened turns due instability Later war longer range fight ers needed long-range bomber es corts CU became issue again way extending Spitfires range especially bigger Griffon engines used later marks situating addi tional tanks behind pilot Eventually larger horizontal vertical stabilizers incorporated allow rear ward center-of-gravity addition larger tail surfaces helped control 2000-plus horsepower output big Griffon engines 12 x 3-in stabilator shown plans Caudimordax longitudinally sta ble will fly large loops want tightening up set up will turn tightly needed point stalling Earlier versions 9 x 3-in tail predictable Construction center rib tip ribs sta bilator lead-out guide bellcrank plate con trol horn engine mount assembly best cut scroll saw band saw en sure accuracy good fit Final shaping can accomplished belt disc sander sure set up tools cut sand perfect 900 angle prefer band saw scroll saw Most scroll saws dont seem have power cut through maple vibration tends obscure guide marks Band saws comparison powerful very smooth can used resawing balsa pine Have ever worked -in pine Slow fuselages cutting alu minum sheet sawing exhaust lugs off engines really nice l0-in-throat three-wheel band saw can obtained Sears little cost Dremel scroll saw Wait until theyre sale can get Christmas Life terrible before got engine mount assembly first glued together very thick CyA cyanoacrylate glue like Special-T What would Combat fliers super glue Make sure grain both balsa spacer 1/64 ply side plates vertical balsa spacer i/ ply plates may look insubstantial two dowels through maple center rib Ive yet have assemblies fail Trial fit engine mark drill holes engine mount assembly must fitted individually its intended center block marking making diagonal cuts maple Remember allow 1/i6 ply front spar Loose-fitting engine mount/center rib combinations can cor rected adding 1/64 ply spacers needed during final assembly aluminum arrow-shaft tail boom can cut length band saw size use 21/64 0D has 019 walls marked 2117 ought avail able good sporting goods store shafts use cutoffs arrows shortened cost quarter Other sizes well graph ite shafts hard come southern Indiana will work just well Use drill press jig some sort drilling hole back cen ter rib Crooked tails get laughed Drill bits available 44-in increments finding right size shouldnt problem Cut notch rear boom us ing band saw Drill two three holes front inch epoxy anchor before gluing boom block together Shallow notches made band saw will work lieu holes Stuff some tissue paper front end boom pre vent epoxy flowing boom Use slow-curing epoxy Make sure notch back end horizontal Cutting foam cores Most Combat con struction articles will tell look else foam cutting instructions method cutting foam first developed Doc Passen easiest method Ive tried yet cutting bow assembled using 1 x 2-in furring strip cutting wire 015 braided control line power source must able supply 12-13 volts 3-4 amps Variac will work does come cheap use car battery Phil Cartier uses light dimmer switch series 200-watt light bulb Write him Core House 760 Waltonville Road Hummelstown PA 17036 details Root tip templates made out -in-thick Formica edges must sanded smooth possible Candle wax rubbed edges also helps straight cuts Note centerline templates 7/ bottom compen sate fact foam rarely exactly two inches thick also 1/16 lost foam cut Put guide marks templates shown both sides well top guiding edge template patterns edge plans make convenient Xeroxing Paste Xeroxed patterns onto Formica cutting surface prepared driving nails through flat piece plywood par ticle board nails serve hold foam down flat during cutting process should penetrate about inch jig should made cutting blanks Two vertical templates needed edge table 27 apart enough space behind accommodate 8-ft -long foam sheets youre really mass production make jigs two feet high cut dozen blanks once Hold layers foam together bam boo shish kebab skewers skewers also useful holding stacks cut wings beds together storage templates held place using double-pointed pins made %-in alumi num brass welding rod Nails December 1990 173 Fly McDaniel Power New Solid State On-Board Glow-Plug Drivers Now can drive 1 2 glow plugs efficiently automatically new McDaniel On-Board Glow-Plug Drivers engine 2 4 stroke glow has 1 2 cylinders Model 471 472 On-Board Glow-Plug Driver will ease jobs starting maintaining idle during taxiing power down flight maneuvers FEATURES INCLUDE Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Connector Plug Battery Pack Remote Glow Plug Indicator Panels Available Separately Battery Pack AC Charger NOT Included Available Separately See Local Hobby Dealer Cantact McDaniel R/C IncVisa MC accepted 1654 Crofton Blvd Suite 4 Crofton MD 21114 e 3017216303 3017216306 NO OCR TEXT r 1 HALFEANLOCK 24 INCHES PATENT PENDING AT LAST positive connector for I HALF glow heads Fits COX glow heads except 020 Two types ring terminals HEAD LOCK/HEAD LITE II adapter ST#050 RING TERM-$595 ST#051 ADAPTER-$695 F IEY AVAILABLE CIDER DIRLT ADD $100 $200 UPSIDE US 12/89 MODEL PRODUCTS CORPORATION POST OFFICE BOX 100 ALLAMUCHY NJ 07820 FAX 201 850 8860 PHONE201 850 1508 IIIWWII AIRCRAFT SCALE DRAWINGS & SPECIFICATION SHEETS Antiques Military CiviIiar Helicopters Saltptanes 2700 ptvs0000 3-view drawirrpIOser 1200 cele FOTO~ K04CU-FANScrIe 3For Csrsisg RANGER FIBERGLASS RANGER FIBERGLASS CO lss bee, Box 879 spesielizirrg ssstorr design nd nrslding Campton NH tire aerospace industry since 1959 03223 S29 Magnum 28 FSR Royal 28 seems well made 25 FSRs far cry earlier Taiwanese engines Its light weight partially due its AAC piston liner As Brat originally intended RC sport flying its induction timing quite con servative Combat use necessary retime induction port replace RC carburetor large-diameter intake stack also known really venturi also helps trim off excess weight head fins dont contribute very much cooling get way changing glow plugs fins can ground off before disassembling engine Remove glow plug plug hole pieces paper toweling Also plug up air intake ex haust Grind off fins using disc belt sander leaving last 3/ intact Wash off filings detergent wa ter before removing paper towel plugs Disassemble engine cylinder liner fits very tightly case must re moved carefully Dont remove bearings Stuff case paper toweling before grinding off muffler lugs Make sure stuff some toweling down exhaust port disc belt sander good way start file can used inaccessible plac es stone Dremel tool also works will clog needs constant dressing Wash filings off detergent water before pulling out paper toweling care filings will enter engine r OFFICIAL AMA SAFETY CODEJanuary 11991 Model Flying Must Accordance Code Order AMA Liability Protection Apply GENERALflown indoors3 will perform initial turn after takeoff away 1 will fly model aircraft competition 7 will operate models metal-bladed pro- tnt spectator areas will there- U after fly over pit speceae U p spectators until has pellers gaseous boosts gases u p oven o rworthy having previ- other sir normal atmospheric pressure en- yond control ous y successfu y flight testedter internal combustion engines nor will I4 will operate model g ad operate models extremely hazardous fuelsfrequencies currently allowed Federal 2 will fly model higher approxi-such containing tetranitromethane orCommunications Commission Only properly Iimately 400 feet within 3 miles airport with-hydrazinecensed Amateurs authorized operate equip- Out notifying airport operator will give right of-way avoid flying proximity full-8 will operate models pyrotechnics anyment Amateur Bsnd frequencies Further scale aircraft necessary observerdevice explodes burns propels projec-any transmitters use sanctioned eveni shall utilized supervise flying avoid hay-tile kind including limited rock-must have certified R/CMA-AMA gold sticker af ing models fly proximity full-scale aircrafteta explosive bombs dropped modelsfixed indicating manufactured modi- U 3 established will abide safety smoke bombs explosive gases such fled operation 20kHz frequency separaeg site use will willfullyhydrogen-filled balloons ground mounted de-lion except 27MHz 53MHzU d de models careless reck-vices launching projectileThe exceptions permitted rockets flown accordance withFREE FLIGHT less and/or dangerous mannerthe Safety Code National Association 4 mode weighs over 20 pounds will onlyRocketry permanently attached per1 will launch mode c aft un ess Ify t n acco dance paragraph 5 sec-JATO use also items authorized Airleast 100 feet downwind spectato auto tion AMA Safety CodeShow Team use defined AST Advisory Coin-mobile parking 5 air shows model flying demonstrations amittee document available AMA HO Note2 will fly model unless launch area single straight line must established sideA model aircraft defined aircraft orclear persons except mechanic offi flying other side spec-without engine able carry human beingcials I tators Only persons essential flight 9 will fly model using turbojet power ax operations permitted flying sideat centrifugal flowi unless have obtained a3 will employ use adequate dev ce n line others must spectatorspecial waiver such specific flights theflight extinguish fuses mode afte de F g spectator side line isAMA President Executive Director willhas completed its function Ip b e beyond control theabide restrictions imposed such flights pilots exceptions may permitby Note does apply ducted fanCONTROL LINE Ited single straight line requirement undermodels using piston engines electric motors special circumstances involving consideration of11 will subject comp m site conditions model size weight speedRADIO CONTROLcluding safety thong applicable inand power must jointly approved AMAspection pull test prior flying President Executive Director maxi-1 twill have completed successful radio equipmum permissible takeoff weight models 55ment ground range check before first flight of21 will assure flying area safely clear Ilbsa new repaired modelof utility wires poles 6 will fly model unless identified with2 will fly model aircraft presence3 will assure fly g a name address AMA number inof spectators until become qualified flier un-of non-essential participants spectators model Note does apply modelsless assisted experienced helperbefore permitting engine started make sure wash out case thoroughly An old toothbrush helps Thoroughly dry oil bearings As stated earlier intake port crankshaft must opened up increase angle remains open Before retiming crank scratch tim ing diagram shown plans onto piece transparent rigid plastic using scribe Thin Plexiglas should work well Insert crankshaft case Slipping drive washer prop nut will help hold shaft proper position Holding engine nose down lay tim ing diagram onto rear engine Line up cross hairs bottom mounting lugs mold flashing centerline engine Referring figure lA rotate shaft un til middle crankpin lines up opening line holding crankshaft position insert hard metal scribe through intake stack make mark crank Use bottom edge frft looking rear side intake port crankcase guide youve set up correctly port should totally closed off shaft doing likewise closing side take port referring figure lB time make mark right side port intake stack can made /2-inOD aluminum nylon brass tubing wall thickness should /32 /16 Wrap Teflon tape around tube ensure good seal intend use remote needle drill tap 6-32 Du-Bro pressure fitting 1/ above stack slips case remote needle made 05 RC needle valve assembly mounted engine bearers using nylon control horn 2-56 sheet metal screws Wash engine parts using hot water dishwashing detergent Dry off parts us ing paper toweling Oil parts WD 40 Break-Free reassemble engine Flying Caudimordax flies best CU line spars using about four five pennies tip weight approximately 13-16 grams Attach streamer test flying Line rake usually set maximum two rearmost holes lead-out guide Brats seem like 7 x 6 Taipan props use 25% Red Max fuel half castor half synthetic oil back-flipping chickenstick technique described Charlie Johnson Combat column seems work best quick starts flying airplane first time check warps Fly level upright note whether either wing appears flying high outboard wing higher inboard very carefully flip airplane onto its back outboard wing flies low have warp still flies high add tip weight outboard wing flies low upright high inverted have warp other way Dont tight turns warped air plane Take home use heat gun shrink covering needed eliminate warp flying against faster opponent use Caudimordaxs superior turning radius advantage Follow opponent through turns advantage level speed negated have actually able fly up others tail pipes occasion Always lookout leading edge kill opponent makes pass streamer often sets him up overshoot thats leading edge kill can ac complished name Caudimordax Doc Passen calls Quasimodo comes Tolkiens book Farmer Giles Ham Naming Combat de signs after weapons named Tolkiens bet ter known book Lord Rings old tra dition Combat circles Orcrist Andu ril English FAI designs instance Glamdring Guthwine Aeglos still up grabs Sting would make good name Anglachel though wouldnt appropriate airplane hope will fly Caudimordax however uniquely appro priate Combat airplane sword also known vulgar tongue Tailbiter habit leaping out its sheath whenever dragon near tra dition time knights kill dra gons cut off tails serve delicacy court sword given Farmer Giles put good use Further development As Combat designs Caudimordax anything static Combat designs evolve faster due high rate destruction Dont afraid try out different airfoils different tail mo ments different construction techniques Per ryman tips Ford Taurus styling Steve Hills Arrowplane wont will can stick Fox 36 nose please use least 34-in-thick wood center block 3/4 x 3A-in maple engine mounts never build Caudimordax article others ought give few ideas improve other design design own Nearly construction techniques used airplane filched others Id like thank too ideas used design Terry Doc Passen foam cutting engine retiming techniques tail hinge bellcrank mount pushrod Phil Cartier arrow-shaft tail boom techniques bladder compartment idea using smaller engines first place Rich ard Wilkens front spar foam cutting bow CL Scale/Boss Continued page 72 Ontario Canada CL Scale judged June 30th flown July 1st Mike reports disappointing CL Scale entry five Two Canadians other three US Its surprising US modelers north central area country werent hand com petition contest site about three hours Buffalo NY about two hours Detroit MI well within days drive several north central statesContinued page 178 December 1990 177 DOE Z2Li2 TNROFILES AND SUPPLIES FOR ELECTRIC FLIGHT SM5 1 6 cells tu u amps SM4 7 23 cells 50 amps Sc6 24 34 cells 60 amps -all throttles linear proportional forward only#15 WiRE 350 STRAND 020 25 size #12 WIRE 665 STRAND 25 100 siz Toas ac4da6ge s 44ff Call write JOMAR 513-474-0985 2028 Knightsbridge Dr. Cincinnati OH 45244
Edition: Model Aviation - 1990/12
Page Numbers: 68, 69, 70, 71, 172, 173, 174, 176, 177
Caudimordax Fast Combat smaller engines works Three ounces fuel can last up five minutes shoulder stays piece slower tight-turning ship gives edge over opponentand engine costs lot less Hlskandar Taib AMERICAN COMBAT design philosophy has traditionally favored speed over turning ability Note large sums money spent Hoffelts custom Foxes bolted onto 300- 400-sq-in airplanes weighing 21 oz What en gines share besides enormous power output weight Most weigh about 9/2 oz Caudimordax design takes other approach high rate turn small turning radius given top priority qualities achieved using light engine high aspect ratio wing compromise speed Caudimordax Brat 28 flies 10 15 mph slower level flight typical Fast Combat job makes up turns though much tighter actually slow down ship much less would heavier model Flying Fast Combat smaller engines has other advantages Three ounces fuel Left left unmodified Brat 28 stIll sporting its RC carburetor author has several give away right modified Brat 28 Note missing metal around exhaust port thinned head fins homemade venturi 7 x 6 Talpal prop Right Close-up view remote needle valve assembly unit OS 10 FSR RC used Note short length tubing slipped over end needle valve prevent leakage plastic clip fuel line available author 68 Model Aviation Author/builder Iskandar Taib holding Caudimordax thoroughly designed Combat plane gives up some top speed typically 10-15 mph makes up barely slowing corners Light weight along special modifications engine make possible Left Mark made crankshaft intake ports closing side Right Mark made opening side Note amount metal has removed Brats have very conservative timing befits its sport RC roots Left Front end tail boom Note shallow cuts made aluminum epoxy grab Small holes may drilled instead Right Engine mount assembly center rib Mount marked sawing using front center rib pattern ft Components horizontal stabilizer Start epoxying arrow shaft stab anchor Glue hinge assembly stab anchor cover horizontal stab -In medium balsa glue stab anchor Right completed tail assembly Notice hinge built String wrapped figure-eight pattern around two 3As dowels December 1990 69 F 4 4 \ - will last five minutes airplane doesnt dislocate shoulder its fast cant keep up slower tight-turning airplane can also hard opponent line up have gotten several kills other guy overshot attack Perhaps important engines cost far less bigger counterparts Caudimordax can also used Out law FAJ contests sprouting up over Midwest Rules typically specify Fast Slow rules 15 engines 52-ft lines no restrictions engine tank setups nitro content fuel Most Schnuerle-ported double ball bear ing 15s weigh about six ounces 34 oz less Brat 28 modifications needed use slightly smaller typically l/ engine bearer spacing mount engine slightly further ward Caudimordax design goes back sev eral years evolving slowly its present form admittedly incorporating features currently vogue External con trols instance now being used top fliers including Russians save much building time allowing use solid wing panels Another great time-saver simple cutout blad der tank replaces common rocket tube arrow-shaft tail boom al though requires little extra building time allows easier rebuilding saves little weight agility Caudimordax attribut able its high aspect ratio wing thick airfoil high aspect ratio reduces tip vortices cause induced drag thick airfoil delays onset high-speed stall thick airfoil also lends lateral sta FAST COMBAT DESIGN ESR 23-32 ENGINES bility design helps control snap rolling associated high aspect ratio designs Induced drag Just what induced drag its reduction important Combat design Drag generally divided two types often confused Parasitic drag caused friction air surface airplane therefore proportional surface area wing Also included category drag lines drag caused protuberances airplane such pushrod engine cylinder Streamlining serves reduce parasitic drag Induced drag other hand re lated lift produced wing wing producing lift pressure air bottom surface wing greater pressure top pressure differences cause air above wings move outward toward wing tips air below wings move toward root tips nothing pre vent air below wings curling around tips pushing down top surface wing reducing actual amount lift produced airflow around wing tip also pro duces turbulent vortices often visible va por trails emanating wing tips jet fighters during high-G maneuvers energy needed drive vortices ulti mately Linked drag drag sociated vortices de scribed induced drag greater lift 70 Model Aviation Pushrod braces made outer Sullivan Ny-Rod Filament tape wraps tail boom bed nails particular piece made out straight section chip-core board Full-Size Plans Available. Page 200 nI 1~ ** TJ / produced wing larger vor tices Several strategies exist reduction tip vortices Tip fences instance will impede air flowing around wing tips Low aspect ratio wings would benefit tip fences Ed Brzys listen ing Theyve seen full-scale air planes low aspect ratio wings such pretty Racing biplane Sorceress Hoer ner anti-vortex tips variation tip fence shaped force airflow tips counter direction tip vor tex However work air plane experiences positive Gs Flip air plane its back anti-vortex tips ac tually add problem Forward sweep wing causes air flow move toward root can spill cause vortex forward swept wings have extremely rigid withstand aeroelastic twisting forces increase wing twists technically known aeroelastic divergence Another way improve efficiency lift/drag ratio wing use smaller wing tip Wind tunnel experiments have shown Schuemann planform shouldnt called George Perryman planform currently vogue glider pi lots has least amount induced drag given amount lift elliptical planform eg Spitfire almost good wing no taper 60% 65% efficient elliptical wing same pect ratio wing tip chord 60% 65% root chord 90% 95% efficient turn tapered wing produces lot less induced drag nontapered High aspect ratio wings have smaller amounts tip spillage low aspect ratio wings less wing tip length per unit area Glider wings have high aspect ratios very purpose High aspect ratio wings have own problems however main being added bending stresses put Continued page 172 Left Cutting top surface wing core Core held tightly board embedded nalis Note bow held Right Cutting spar slot Slot cut single pass down back up Author gives complete directions foam wing cutting something rarely done December 1990 71 / 7- design drawing Nur Iskandar Taib modela fill need hotdog show-off sport plane Knife edge take-offs flat apins snaps anything can Wing foam Fuselage Tail lite ply balsa Builds quick lands like trainer Flyingweight lOlba 184 1 l3lbs 192 Ohio OHIO SUPERSTAR PRODUCTS INC 11376 RIOGEWAY ROADKENSINGTON OHIO 44427 r 216-223-1950 great idea cant resist quoting Mr Stahls comments opening paragraph Overemphasis strictly flying designs con tests throughout country recent years has brought about unwarranted condition ne glect building flying Scale semiscale models Much favoritism must tributed desire maximum performance since little need said relative appearance neatly built Scale ship usual contest design SAM Italia Dr Ferdinando Gale Baveno aly recently sent interesting handbook about Eastern bloc engines written Cesare de Robertis Well illustrated unusual model power plants text Italian available Gale Via Marconi 10 28042 Baveno NO Italy interesting material de signs emerging SAM Italia including several magnificent construction drawings beautiful Italian Gliders pre-WW II era available B2 Streamlines PO Box 976 Olalla WA 98359 RC Pylon/Hager Continued page 64 no mediocre planes event fact well done dont know pilots selected would show two three brought along would still out trying decide Id vote collection absolutely beautiful takeoff area too narrow support four planes up heats threeplane blasts Plans have made things works widen takeoff area fourplane heats can accommodated next spring top 10 finishers Saturday 1 Randy Rich 11480 2 Richard Oliver 11701 3 Red Cranfield 12189 4 Phil Bussell 11742 5 Jim Young 11859 6 Bill Hager 11539 7 Hubert Wills 11905 8 Norm Johnson 11473 9 Dub Jets 11487 10 Sam Womack 11656 Just keep everyones attention two midairs Saturday both occurring just out turn number three Poor Bob Greer par ticipant little high-speed tangos Dave Layman Bill Hager Jerry Small tried trade little paint flight wound up getting planes dirty easier transport under seat Sundays action just hot heavy make sure moves down pat Bob Greer provided present what violent midair collision since vention prop happened about 20 ft di rectly behind above head stood cage turn number pilot lane made clock locked ac tion happened felt bad pilots crash itself right out movies another midair just out turn number three tame comparison Bob Greer/Hubert Wills fiasco earlier com pletely forgot get names pilots volved Yours Truly Bill Hager Jerry SmallBH Top five finishers Sunday 1 Dub Jett 11685 2 Red Cranfield l193 Phil Bussell 12059 4 Bill Hager 11614 5 Montie Montcrief 11620 6 Clay Gary 11509 7 Dave Layman 11381 8 Norm Johnson 11415 9 Randy Ritch 11529 10 Sam Wo mack 12772 Fast time meet 11090 turned Jerry Small lot really good close tight racing action both days can per sonally vouch quality food available heard nothing praise con dition fieldits size its location think two quotes heard often Yall have best racing facilities around grass field absolutely fantastic shape nice words made feel kinda proud field proud have small part core club members come out work event got meet some super-nice guys see some beautiful planes doin some really competitive racing besides Bob Greer Ill long time talking about Sun day midair yours Take guys put first-class race the field great shape See next month Caudimordax/Taib Continued page 71 wing lift being generated farther out root Very high aspect ratio wings demand extra strength conse quently added weight spars root particular application will demand aspect ratio provides best combi nation weight efficiency Cau dimordax aspect ratio 61 cho sen allowed convenient wing span 48 inches Styrofoam comes 2-ftwide sheetsjust right wing panel mean chord eight inches al lows 10-in root 6-in tip 60% tip/root percentage Such wing core too difficult cut trailing edge swept forward three inches lead ing edge swept back inch producing net sweep quarter-chord zero Experiments straight leading edge produced airplanes unpleasant snap rolling tendencies swept leading edge also allows easier placement spars greater lead-out sweep Eliminating high-speed stall Turning airplane too tightly causes wing stall wing forced produce lift capable producing produce lift angle attack must creased Beyond certain angle attack air flow along top wing separates wings surface becomes turbu lent causing sudden increase drag Most Combat fliers adjust controls limit turn radius order avoid stal ling Another approach use thicker blunter airfoil stalls higher Us thin does drawback ap proach course thicker airfoil has greater parasitic drag top speed reduced accordingly Caudimordax root section thick 15% tip thicker 25% relatively thicker tip airfoil ensures root will stall first turn thus reduc ing airplanes tendency drop wing tip tendency causes lateral instabil ity common high aspect ratio Combat wings Longitudinal stability An airplane does tight fast turns absolutely no use cant make go want go common problem Combat wings lack longitudinal stability turn once started will tighten up its own ac cord makes airplane unpointable therefore useless Combat air plane should also able fly straight unattended An unstable airplane will tend tighten wander out turn pilot glances away inslant common misconception sta 172 Model Aviation SPORTOBATIC 2 84 For1204cycleand 902-cycle rST 200025003000-0 PS 18 NEWOS BGX 13500 bilator elevator make airplane move up down true designer could reduce stabilator area airplane thats overly sensitive unstable Actually opposite true stabilator provides stability opposing downward pitching moment produced wing larger stabilizer larger airplanes stability margin since stabilizer doesnt have work hard Similarly longer tail moment increases stability providing longer moment arm stabilizer act Spitfire airplane too small horizontal stabilizer earlier marks had very small acceptable range CG center-of-gravity ad ditional equipment added aft ac ceptable range aircrafts stability de creased fact several structural failures traced directly aircraft tight ened turns due instability Later war longer range fight ers needed long-range bomber es corts CU became issue again way extending Spitfires range especially bigger Griffon engines used later marks situating addi tional tanks behind pilot Eventually larger horizontal vertical stabilizers incorporated allow rear ward center-of-gravity addition larger tail surfaces helped control 2000-plus horsepower output big Griffon engines 12 x 3-in stabilator shown plans Caudimordax longitudinally sta ble will fly large loops want tightening up set up will turn tightly needed point stalling Earlier versions 9 x 3-in tail predictable Construction center rib tip ribs sta bilator lead-out guide bellcrank plate con trol horn engine mount assembly best cut scroll saw band saw en sure accuracy good fit Final shaping can accomplished belt disc sander sure set up tools cut sand perfect 900 angle prefer band saw scroll saw Most scroll saws dont seem have power cut through maple vibration tends obscure guide marks Band saws comparison powerful very smooth can used resawing balsa pine Have ever worked -in pine Slow fuselages cutting alu minum sheet sawing exhaust lugs off engines really nice l0-in-throat three-wheel band saw can obtained Sears little cost Dremel scroll saw Wait until theyre sale can get Christmas Life terrible before got engine mount assembly first glued together very thick CyA cyanoacrylate glue like Special-T What would Combat fliers super glue Make sure grain both balsa spacer 1/64 ply side plates vertical balsa spacer i/ ply plates may look insubstantial two dowels through maple center rib Ive yet have assemblies fail Trial fit engine mark drill holes engine mount assembly must fitted individually its intended center block marking making diagonal cuts maple Remember allow 1/i6 ply front spar Loose-fitting engine mount/center rib combinations can cor rected adding 1/64 ply spacers needed during final assembly aluminum arrow-shaft tail boom can cut length band saw size use 21/64 0D has 019 walls marked 2117 ought avail able good sporting goods store shafts use cutoffs arrows shortened cost quarter Other sizes well graph ite shafts hard come southern Indiana will work just well Use drill press jig some sort drilling hole back cen ter rib Crooked tails get laughed Drill bits available 44-in increments finding right size shouldnt problem Cut notch rear boom us ing band saw Drill two three holes front inch epoxy anchor before gluing boom block together Shallow notches made band saw will work lieu holes Stuff some tissue paper front end boom pre vent epoxy flowing boom Use slow-curing epoxy Make sure notch back end horizontal Cutting foam cores Most Combat con struction articles will tell look else foam cutting instructions method cutting foam first developed Doc Passen easiest method Ive tried yet cutting bow assembled using 1 x 2-in furring strip cutting wire 015 braided control line power source must able supply 12-13 volts 3-4 amps Variac will work does come cheap use car battery Phil Cartier uses light dimmer switch series 200-watt light bulb Write him Core House 760 Waltonville Road Hummelstown PA 17036 details Root tip templates made out -in-thick Formica edges must sanded smooth possible Candle wax rubbed edges also helps straight cuts Note centerline templates 7/ bottom compen sate fact foam rarely exactly two inches thick also 1/16 lost foam cut Put guide marks templates shown both sides well top guiding edge template patterns edge plans make convenient Xeroxing Paste Xeroxed patterns onto Formica cutting surface prepared driving nails through flat piece plywood par ticle board nails serve hold foam down flat during cutting process should penetrate about inch jig should made cutting blanks Two vertical templates needed edge table 27 apart enough space behind accommodate 8-ft -long foam sheets youre really mass production make jigs two feet high cut dozen blanks once Hold layers foam together bam boo shish kebab skewers skewers also useful holding stacks cut wings beds together storage templates held place using double-pointed pins made %-in alumi num brass welding rod Nails December 1990 173 Fly McDaniel Power New Solid State On-Board Glow-Plug Drivers Now can drive 1 2 glow plugs efficiently automatically new McDaniel On-Board Glow-Plug Drivers engine 2 4 stroke glow has 1 2 cylinders Model 471 472 On-Board Glow-Plug Driver will ease jobs starting maintaining idle during taxiing power down flight maneuvers FEATURES INCLUDE Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Connector Plug Battery Pack Remote Glow Plug Indicator Panels Available Separately Battery Pack AC Charger NOT Included Available Separately See Local Hobby Dealer Cantact McDaniel R/C IncVisa MC accepted 1654 Crofton Blvd Suite 4 Crofton MD 21114 e 3017216303 3017216306 NO OCR TEXT r 1 HALFEANLOCK 24 INCHES PATENT PENDING AT LAST positive connector for I HALF glow heads Fits COX glow heads except 020 Two types ring terminals HEAD LOCK/HEAD LITE II adapter ST#050 RING TERM-$595 ST#051 ADAPTER-$695 F IEY AVAILABLE CIDER DIRLT ADD $100 $200 UPSIDE US 12/89 MODEL PRODUCTS CORPORATION POST OFFICE BOX 100 ALLAMUCHY NJ 07820 FAX 201 850 8860 PHONE201 850 1508 IIIWWII AIRCRAFT SCALE DRAWINGS & SPECIFICATION SHEETS Antiques Military CiviIiar Helicopters Saltptanes 2700 ptvs0000 3-view drawirrpIOser 1200 cele FOTO~ K04CU-FANScrIe 3For Csrsisg RANGER FIBERGLASS RANGER FIBERGLASS CO lss bee, Box 879 spesielizirrg ssstorr design nd nrslding Campton NH tire aerospace industry since 1959 03223 S29 Magnum 28 FSR Royal 28 seems well made 25 FSRs far cry earlier Taiwanese engines Its light weight partially due its AAC piston liner As Brat originally intended RC sport flying its induction timing quite con servative Combat use necessary retime induction port replace RC carburetor large-diameter intake stack also known really venturi also helps trim off excess weight head fins dont contribute very much cooling get way changing glow plugs fins can ground off before disassembling engine Remove glow plug plug hole pieces paper toweling Also plug up air intake ex haust Grind off fins using disc belt sander leaving last 3/ intact Wash off filings detergent wa ter before removing paper towel plugs Disassemble engine cylinder liner fits very tightly case must re moved carefully Dont remove bearings Stuff case paper toweling before grinding off muffler lugs Make sure stuff some toweling down exhaust port disc belt sander good way start file can used inaccessible plac es stone Dremel tool also works will clog needs constant dressing Wash filings off detergent water before pulling out paper toweling care filings will enter engine r OFFICIAL AMA SAFETY CODEJanuary 11991 Model Flying Must Accordance Code Order AMA Liability Protection Apply GENERALflown indoors3 will perform initial turn after takeoff away 1 will fly model aircraft competition 7 will operate models metal-bladed pro- tnt spectator areas will there- U after fly over pit speceae U p spectators until has pellers gaseous boosts gases u p oven o rworthy having previ- other sir normal atmospheric pressure en- yond control ous y successfu y flight testedter internal combustion engines nor will I4 will operate model g ad operate models extremely hazardous fuelsfrequencies currently allowed Federal 2 will fly model higher approxi-such containing tetranitromethane orCommunications Commission Only properly Iimately 400 feet within 3 miles airport with-hydrazinecensed Amateurs authorized operate equip- Out notifying airport operator will give right of-way avoid flying proximity full-8 will operate models pyrotechnics anyment Amateur Bsnd frequencies Further scale aircraft necessary observerdevice explodes burns propels projec-any transmitters use sanctioned eveni shall utilized supervise flying avoid hay-tile kind including limited rock-must have certified R/CMA-AMA gold sticker af ing models fly proximity full-scale aircrafteta explosive bombs dropped modelsfixed indicating manufactured modi- U 3 established will abide safety smoke bombs explosive gases such fled operation 20kHz frequency separaeg site use will willfullyhydrogen-filled balloons ground mounted de-lion except 27MHz 53MHzU d de models careless reck-vices launching projectileThe exceptions permitted rockets flown accordance withFREE FLIGHT less and/or dangerous mannerthe Safety Code National Association 4 mode weighs over 20 pounds will onlyRocketry permanently attached per1 will launch mode c aft un ess Ify t n acco dance paragraph 5 sec-JATO use also items authorized Airleast 100 feet downwind spectato auto tion AMA Safety CodeShow Team use defined AST Advisory Coin-mobile parking 5 air shows model flying demonstrations amittee document available AMA HO Note2 will fly model unless launch area single straight line must established sideA model aircraft defined aircraft orclear persons except mechanic offi flying other side spec-without engine able carry human beingcials I tators Only persons essential flight 9 will fly model using turbojet power ax operations permitted flying sideat centrifugal flowi unless have obtained a3 will employ use adequate dev ce n line others must spectatorspecial waiver such specific flights theflight extinguish fuses mode afte de F g spectator side line isAMA President Executive Director willhas completed its function Ip b e beyond control theabide restrictions imposed such flights pilots exceptions may permitby Note does apply ducted fanCONTROL LINE Ited single straight line requirement undermodels using piston engines electric motors special circumstances involving consideration of11 will subject comp m site conditions model size weight speedRADIO CONTROLcluding safety thong applicable inand power must jointly approved AMAspection pull test prior flying President Executive Director maxi-1 twill have completed successful radio equipmum permissible takeoff weight models 55ment ground range check before first flight of21 will assure flying area safely clear Ilbsa new repaired modelof utility wires poles 6 will fly model unless identified with2 will fly model aircraft presence3 will assure fly g a name address AMA number inof spectators until become qualified flier un-of non-essential participants spectators model Note does apply modelsless assisted experienced helperbefore permitting engine started make sure wash out case thoroughly An old toothbrush helps Thoroughly dry oil bearings As stated earlier intake port crankshaft must opened up increase angle remains open Before retiming crank scratch tim ing diagram shown plans onto piece transparent rigid plastic using scribe Thin Plexiglas should work well Insert crankshaft case Slipping drive washer prop nut will help hold shaft proper position Holding engine nose down lay tim ing diagram onto rear engine Line up cross hairs bottom mounting lugs mold flashing centerline engine Referring figure lA rotate shaft un til middle crankpin lines up opening line holding crankshaft position insert hard metal scribe through intake stack make mark crank Use bottom edge frft looking rear side intake port crankcase guide youve set up correctly port should totally closed off shaft doing likewise closing side take port referring figure lB time make mark right side port intake stack can made /2-inOD aluminum nylon brass tubing wall thickness should /32 /16 Wrap Teflon tape around tube ensure good seal intend use remote needle drill tap 6-32 Du-Bro pressure fitting 1/ above stack slips case remote needle made 05 RC needle valve assembly mounted engine bearers using nylon control horn 2-56 sheet metal screws Wash engine parts using hot water dishwashing detergent Dry off parts us ing paper toweling Oil parts WD 40 Break-Free reassemble engine Flying Caudimordax flies best CU line spars using about four five pennies tip weight approximately 13-16 grams Attach streamer test flying Line rake usually set maximum two rearmost holes lead-out guide Brats seem like 7 x 6 Taipan props use 25% Red Max fuel half castor half synthetic oil back-flipping chickenstick technique described Charlie Johnson Combat column seems work best quick starts flying airplane first time check warps Fly level upright note whether either wing appears flying high outboard wing higher inboard very carefully flip airplane onto its back outboard wing flies low have warp still flies high add tip weight outboard wing flies low upright high inverted have warp other way Dont tight turns warped air plane Take home use heat gun shrink covering needed eliminate warp flying against faster opponent use Caudimordaxs superior turning radius advantage Follow opponent through turns advantage level speed negated have actually able fly up others tail pipes occasion Always lookout leading edge kill opponent makes pass streamer often sets him up overshoot thats leading edge kill can ac complished name Caudimordax Doc Passen calls Quasimodo comes Tolkiens book Farmer Giles Ham Naming Combat de signs after weapons named Tolkiens bet ter known book Lord Rings old tra dition Combat circles Orcrist Andu ril English FAI designs instance Glamdring Guthwine Aeglos still up grabs Sting would make good name Anglachel though wouldnt appropriate airplane hope will fly Caudimordax however uniquely appro priate Combat airplane sword also known vulgar tongue Tailbiter habit leaping out its sheath whenever dragon near tra dition time knights kill dra gons cut off tails serve delicacy court sword given Farmer Giles put good use Further development As Combat designs Caudimordax anything static Combat designs evolve faster due high rate destruction Dont afraid try out different airfoils different tail mo ments different construction techniques Per ryman tips Ford Taurus styling Steve Hills Arrowplane wont will can stick Fox 36 nose please use least 34-in-thick wood center block 3/4 x 3A-in maple engine mounts never build Caudimordax article others ought give few ideas improve other design design own Nearly construction techniques used airplane filched others Id like thank too ideas used design Terry Doc Passen foam cutting engine retiming techniques tail hinge bellcrank mount pushrod Phil Cartier arrow-shaft tail boom techniques bladder compartment idea using smaller engines first place Rich ard Wilkens front spar foam cutting bow CL Scale/Boss Continued page 72 Ontario Canada CL Scale judged June 30th flown July 1st Mike reports disappointing CL Scale entry five Two Canadians other three US Its surprising US modelers north central area country werent hand com petition contest site about three hours Buffalo NY about two hours Detroit MI well within days drive several north central statesContinued page 178 December 1990 177 DOE Z2Li2 TNROFILES AND SUPPLIES FOR ELECTRIC FLIGHT SM5 1 6 cells tu u amps SM4 7 23 cells 50 amps Sc6 24 34 cells 60 amps -all throttles linear proportional forward only#15 WiRE 350 STRAND 020 25 size #12 WIRE 665 STRAND 25 100 siz Toas ac4da6ge s 44ff Call write JOMAR 513-474-0985 2028 Knightsbridge Dr. Cincinnati OH 45244
Edition: Model Aviation - 1990/12
Page Numbers: 68, 69, 70, 71, 172, 173, 174, 176, 177
Caudimordax Fast Combat smaller engines works Three ounces fuel can last up five minutes shoulder stays piece slower tight-turning ship gives edge over opponentand engine costs lot less Hlskandar Taib AMERICAN COMBAT design philosophy has traditionally favored speed over turning ability Note large sums money spent Hoffelts custom Foxes bolted onto 300- 400-sq-in airplanes weighing 21 oz What en gines share besides enormous power output weight Most weigh about 9/2 oz Caudimordax design takes other approach high rate turn small turning radius given top priority qualities achieved using light engine high aspect ratio wing compromise speed Caudimordax Brat 28 flies 10 15 mph slower level flight typical Fast Combat job makes up turns though much tighter actually slow down ship much less would heavier model Flying Fast Combat smaller engines has other advantages Three ounces fuel Left left unmodified Brat 28 stIll sporting its RC carburetor author has several give away right modified Brat 28 Note missing metal around exhaust port thinned head fins homemade venturi 7 x 6 Talpal prop Right Close-up view remote needle valve assembly unit OS 10 FSR RC used Note short length tubing slipped over end needle valve prevent leakage plastic clip fuel line available author 68 Model Aviation Author/builder Iskandar Taib holding Caudimordax thoroughly designed Combat plane gives up some top speed typically 10-15 mph makes up barely slowing corners Light weight along special modifications engine make possible Left Mark made crankshaft intake ports closing side Right Mark made opening side Note amount metal has removed Brats have very conservative timing befits its sport RC roots Left Front end tail boom Note shallow cuts made aluminum epoxy grab Small holes may drilled instead Right Engine mount assembly center rib Mount marked sawing using front center rib pattern ft Components horizontal stabilizer Start epoxying arrow shaft stab anchor Glue hinge assembly stab anchor cover horizontal stab -In medium balsa glue stab anchor Right completed tail assembly Notice hinge built String wrapped figure-eight pattern around two 3As dowels December 1990 69 F 4 4 \ - will last five minutes airplane doesnt dislocate shoulder its fast cant keep up slower tight-turning airplane can also hard opponent line up have gotten several kills other guy overshot attack Perhaps important engines cost far less bigger counterparts Caudimordax can also used Out law FAJ contests sprouting up over Midwest Rules typically specify Fast Slow rules 15 engines 52-ft lines no restrictions engine tank setups nitro content fuel Most Schnuerle-ported double ball bear ing 15s weigh about six ounces 34 oz less Brat 28 modifications needed use slightly smaller typically l/ engine bearer spacing mount engine slightly further ward Caudimordax design goes back sev eral years evolving slowly its present form admittedly incorporating features currently vogue External con trols instance now being used top fliers including Russians save much building time allowing use solid wing panels Another great time-saver simple cutout blad der tank replaces common rocket tube arrow-shaft tail boom al though requires little extra building time allows easier rebuilding saves little weight agility Caudimordax attribut able its high aspect ratio wing thick airfoil high aspect ratio reduces tip vortices cause induced drag thick airfoil delays onset high-speed stall thick airfoil also lends lateral sta FAST COMBAT DESIGN ESR 23-32 ENGINES bility design helps control snap rolling associated high aspect ratio designs Induced drag Just what induced drag its reduction important Combat design Drag generally divided two types often confused Parasitic drag caused friction air surface airplane therefore proportional surface area wing Also included category drag lines drag caused protuberances airplane such pushrod engine cylinder Streamlining serves reduce parasitic drag Induced drag other hand re lated lift produced wing wing producing lift pressure air bottom surface wing greater pressure top pressure differences cause air above wings move outward toward wing tips air below wings move toward root tips nothing pre vent air below wings curling around tips pushing down top surface wing reducing actual amount lift produced airflow around wing tip also pro duces turbulent vortices often visible va por trails emanating wing tips jet fighters during high-G maneuvers energy needed drive vortices ulti mately Linked drag drag sociated vortices de scribed induced drag greater lift 70 Model Aviation Pushrod braces made outer Sullivan Ny-Rod Filament tape wraps tail boom bed nails particular piece made out straight section chip-core board Full-Size Plans Available. Page 200 nI 1~ ** TJ / produced wing larger vor tices Several strategies exist reduction tip vortices Tip fences instance will impede air flowing around wing tips Low aspect ratio wings would benefit tip fences Ed Brzys listen ing Theyve seen full-scale air planes low aspect ratio wings such pretty Racing biplane Sorceress Hoer ner anti-vortex tips variation tip fence shaped force airflow tips counter direction tip vor tex However work air plane experiences positive Gs Flip air plane its back anti-vortex tips ac tually add problem Forward sweep wing causes air flow move toward root can spill cause vortex forward swept wings have extremely rigid withstand aeroelastic twisting forces increase wing twists technically known aeroelastic divergence Another way improve efficiency lift/drag ratio wing use smaller wing tip Wind tunnel experiments have shown Schuemann planform shouldnt called George Perryman planform currently vogue glider pi lots has least amount induced drag given amount lift elliptical planform eg Spitfire almost good wing no taper 60% 65% efficient elliptical wing same pect ratio wing tip chord 60% 65% root chord 90% 95% efficient turn tapered wing produces lot less induced drag nontapered High aspect ratio wings have smaller amounts tip spillage low aspect ratio wings less wing tip length per unit area Glider wings have high aspect ratios very purpose High aspect ratio wings have own problems however main being added bending stresses put Continued page 172 Left Cutting top surface wing core Core held tightly board embedded nalis Note bow held Right Cutting spar slot Slot cut single pass down back up Author gives complete directions foam wing cutting something rarely done December 1990 71 / 7- design drawing Nur Iskandar Taib modela fill need hotdog show-off sport plane Knife edge take-offs flat apins snaps anything can Wing foam Fuselage Tail lite ply balsa Builds quick lands like trainer Flyingweight lOlba 184 1 l3lbs 192 Ohio OHIO SUPERSTAR PRODUCTS INC 11376 RIOGEWAY ROADKENSINGTON OHIO 44427 r 216-223-1950 great idea cant resist quoting Mr Stahls comments opening paragraph Overemphasis strictly flying designs con tests throughout country recent years has brought about unwarranted condition ne glect building flying Scale semiscale models Much favoritism must tributed desire maximum performance since little need said relative appearance neatly built Scale ship usual contest design SAM Italia Dr Ferdinando Gale Baveno aly recently sent interesting handbook about Eastern bloc engines written Cesare de Robertis Well illustrated unusual model power plants text Italian available Gale Via Marconi 10 28042 Baveno NO Italy interesting material de signs emerging SAM Italia including several magnificent construction drawings beautiful Italian Gliders pre-WW II era available B2 Streamlines PO Box 976 Olalla WA 98359 RC Pylon/Hager Continued page 64 no mediocre planes event fact well done dont know pilots selected would show two three brought along would still out trying decide Id vote collection absolutely beautiful takeoff area too narrow support four planes up heats threeplane blasts Plans have made things works widen takeoff area fourplane heats can accommodated next spring top 10 finishers Saturday 1 Randy Rich 11480 2 Richard Oliver 11701 3 Red Cranfield 12189 4 Phil Bussell 11742 5 Jim Young 11859 6 Bill Hager 11539 7 Hubert Wills 11905 8 Norm Johnson 11473 9 Dub Jets 11487 10 Sam Womack 11656 Just keep everyones attention two midairs Saturday both occurring just out turn number three Poor Bob Greer par ticipant little high-speed tangos Dave Layman Bill Hager Jerry Small tried trade little paint flight wound up getting planes dirty easier transport under seat Sundays action just hot heavy make sure moves down pat Bob Greer provided present what violent midair collision since vention prop happened about 20 ft di rectly behind above head stood cage turn number pilot lane made clock locked ac tion happened felt bad pilots crash itself right out movies another midair just out turn number three tame comparison Bob Greer/Hubert Wills fiasco earlier com pletely forgot get names pilots volved Yours Truly Bill Hager Jerry SmallBH Top five finishers Sunday 1 Dub Jett 11685 2 Red Cranfield l193 Phil Bussell 12059 4 Bill Hager 11614 5 Montie Montcrief 11620 6 Clay Gary 11509 7 Dave Layman 11381 8 Norm Johnson 11415 9 Randy Ritch 11529 10 Sam Wo mack 12772 Fast time meet 11090 turned Jerry Small lot really good close tight racing action both days can per sonally vouch quality food available heard nothing praise con dition fieldits size its location think two quotes heard often Yall have best racing facilities around grass field absolutely fantastic shape nice words made feel kinda proud field proud have small part core club members come out work event got meet some super-nice guys see some beautiful planes doin some really competitive racing besides Bob Greer Ill long time talking about Sun day midair yours Take guys put first-class race the field great shape See next month Caudimordax/Taib Continued page 71 wing lift being generated farther out root Very high aspect ratio wings demand extra strength conse quently added weight spars root particular application will demand aspect ratio provides best combi nation weight efficiency Cau dimordax aspect ratio 61 cho sen allowed convenient wing span 48 inches Styrofoam comes 2-ftwide sheetsjust right wing panel mean chord eight inches al lows 10-in root 6-in tip 60% tip/root percentage Such wing core too difficult cut trailing edge swept forward three inches lead ing edge swept back inch producing net sweep quarter-chord zero Experiments straight leading edge produced airplanes unpleasant snap rolling tendencies swept leading edge also allows easier placement spars greater lead-out sweep Eliminating high-speed stall Turning airplane too tightly causes wing stall wing forced produce lift capable producing produce lift angle attack must creased Beyond certain angle attack air flow along top wing separates wings surface becomes turbu lent causing sudden increase drag Most Combat fliers adjust controls limit turn radius order avoid stal ling Another approach use thicker blunter airfoil stalls higher Us thin does drawback ap proach course thicker airfoil has greater parasitic drag top speed reduced accordingly Caudimordax root section thick 15% tip thicker 25% relatively thicker tip airfoil ensures root will stall first turn thus reduc ing airplanes tendency drop wing tip tendency causes lateral instabil ity common high aspect ratio Combat wings Longitudinal stability An airplane does tight fast turns absolutely no use cant make go want go common problem Combat wings lack longitudinal stability turn once started will tighten up its own ac cord makes airplane unpointable therefore useless Combat air plane should also able fly straight unattended An unstable airplane will tend tighten wander out turn pilot glances away inslant common misconception sta 172 Model Aviation SPORTOBATIC 2 84 For1204cycleand 902-cycle rST 200025003000-0 PS 18 NEWOS BGX 13500 bilator elevator make airplane move up down true designer could reduce stabilator area airplane thats overly sensitive unstable Actually opposite true stabilator provides stability opposing downward pitching moment produced wing larger stabilizer larger airplanes stability margin since stabilizer doesnt have work hard Similarly longer tail moment increases stability providing longer moment arm stabilizer act Spitfire airplane too small horizontal stabilizer earlier marks had very small acceptable range CG center-of-gravity ad ditional equipment added aft ac ceptable range aircrafts stability de creased fact several structural failures traced directly aircraft tight ened turns due instability Later war longer range fight ers needed long-range bomber es corts CU became issue again way extending Spitfires range especially bigger Griffon engines used later marks situating addi tional tanks behind pilot Eventually larger horizontal vertical stabilizers incorporated allow rear ward center-of-gravity addition larger tail surfaces helped control 2000-plus horsepower output big Griffon engines 12 x 3-in stabilator shown plans Caudimordax longitudinally sta ble will fly large loops want tightening up set up will turn tightly needed point stalling Earlier versions 9 x 3-in tail predictable Construction center rib tip ribs sta bilator lead-out guide bellcrank plate con trol horn engine mount assembly best cut scroll saw band saw en sure accuracy good fit Final shaping can accomplished belt disc sander sure set up tools cut sand perfect 900 angle prefer band saw scroll saw Most scroll saws dont seem have power cut through maple vibration tends obscure guide marks Band saws comparison powerful very smooth can used resawing balsa pine Have ever worked -in pine Slow fuselages cutting alu minum sheet sawing exhaust lugs off engines really nice l0-in-throat three-wheel band saw can obtained Sears little cost Dremel scroll saw Wait until theyre sale can get Christmas Life terrible before got engine mount assembly first glued together very thick CyA cyanoacrylate glue like Special-T What would Combat fliers super glue Make sure grain both balsa spacer 1/64 ply side plates vertical balsa spacer i/ ply plates may look insubstantial two dowels through maple center rib Ive yet have assemblies fail Trial fit engine mark drill holes engine mount assembly must fitted individually its intended center block marking making diagonal cuts maple Remember allow 1/i6 ply front spar Loose-fitting engine mount/center rib combinations can cor rected adding 1/64 ply spacers needed during final assembly aluminum arrow-shaft tail boom can cut length band saw size use 21/64 0D has 019 walls marked 2117 ought avail able good sporting goods store shafts use cutoffs arrows shortened cost quarter Other sizes well graph ite shafts hard come southern Indiana will work just well Use drill press jig some sort drilling hole back cen ter rib Crooked tails get laughed Drill bits available 44-in increments finding right size shouldnt problem Cut notch rear boom us ing band saw Drill two three holes front inch epoxy anchor before gluing boom block together Shallow notches made band saw will work lieu holes Stuff some tissue paper front end boom pre vent epoxy flowing boom Use slow-curing epoxy Make sure notch back end horizontal Cutting foam cores Most Combat con struction articles will tell look else foam cutting instructions method cutting foam first developed Doc Passen easiest method Ive tried yet cutting bow assembled using 1 x 2-in furring strip cutting wire 015 braided control line power source must able supply 12-13 volts 3-4 amps Variac will work does come cheap use car battery Phil Cartier uses light dimmer switch series 200-watt light bulb Write him Core House 760 Waltonville Road Hummelstown PA 17036 details Root tip templates made out -in-thick Formica edges must sanded smooth possible Candle wax rubbed edges also helps straight cuts Note centerline templates 7/ bottom compen sate fact foam rarely exactly two inches thick also 1/16 lost foam cut Put guide marks templates shown both sides well top guiding edge template patterns edge plans make convenient Xeroxing Paste Xeroxed patterns onto Formica cutting surface prepared driving nails through flat piece plywood par ticle board nails serve hold foam down flat during cutting process should penetrate about inch jig should made cutting blanks Two vertical templates needed edge table 27 apart enough space behind accommodate 8-ft -long foam sheets youre really mass production make jigs two feet high cut dozen blanks once Hold layers foam together bam boo shish kebab skewers skewers also useful holding stacks cut wings beds together storage templates held place using double-pointed pins made %-in alumi num brass welding rod Nails December 1990 173 Fly McDaniel Power New Solid State On-Board Glow-Plug Drivers Now can drive 1 2 glow plugs efficiently automatically new McDaniel On-Board Glow-Plug Drivers engine 2 4 stroke glow has 1 2 cylinders Model 471 472 On-Board Glow-Plug Driver will ease jobs starting maintaining idle during taxiing power down flight maneuvers FEATURES INCLUDE Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Connector Plug Battery Pack Remote Glow Plug Indicator Panels Available Separately Battery Pack AC Charger NOT Included Available Separately See Local Hobby Dealer Cantact McDaniel R/C IncVisa MC accepted 1654 Crofton Blvd Suite 4 Crofton MD 21114 e 3017216303 3017216306 NO OCR TEXT r 1 HALFEANLOCK 24 INCHES PATENT PENDING AT LAST positive connector for I HALF glow heads Fits COX glow heads except 020 Two types ring terminals HEAD LOCK/HEAD LITE II adapter ST#050 RING TERM-$595 ST#051 ADAPTER-$695 F IEY AVAILABLE CIDER DIRLT ADD $100 $200 UPSIDE US 12/89 MODEL PRODUCTS CORPORATION POST OFFICE BOX 100 ALLAMUCHY NJ 07820 FAX 201 850 8860 PHONE201 850 1508 IIIWWII AIRCRAFT SCALE DRAWINGS & SPECIFICATION SHEETS Antiques Military CiviIiar Helicopters Saltptanes 2700 ptvs0000 3-view drawirrpIOser 1200 cele FOTO~ K04CU-FANScrIe 3For Csrsisg RANGER FIBERGLASS RANGER FIBERGLASS CO lss bee, Box 879 spesielizirrg ssstorr design nd nrslding Campton NH tire aerospace industry since 1959 03223 S29 Magnum 28 FSR Royal 28 seems well made 25 FSRs far cry earlier Taiwanese engines Its light weight partially due its AAC piston liner As Brat originally intended RC sport flying its induction timing quite con servative Combat use necessary retime induction port replace RC carburetor large-diameter intake stack also known really venturi also helps trim off excess weight head fins dont contribute very much cooling get way changing glow plugs fins can ground off before disassembling engine Remove glow plug plug hole pieces paper toweling Also plug up air intake ex haust Grind off fins using disc belt sander leaving last 3/ intact Wash off filings detergent wa ter before removing paper towel plugs Disassemble engine cylinder liner fits very tightly case must re moved carefully Dont remove bearings Stuff case paper toweling before grinding off muffler lugs Make sure stuff some toweling down exhaust port disc belt sander good way start file can used inaccessible plac es stone Dremel tool also works will clog needs constant dressing Wash filings off detergent water before pulling out paper toweling care filings will enter engine r OFFICIAL AMA SAFETY CODEJanuary 11991 Model Flying Must Accordance Code Order AMA Liability Protection Apply GENERALflown indoors3 will perform initial turn after takeoff away 1 will fly model aircraft competition 7 will operate models metal-bladed pro- tnt spectator areas will there- U after fly over pit speceae U p spectators until has pellers gaseous boosts gases u p oven o rworthy having previ- other sir normal atmospheric pressure en- yond control ous y successfu y flight testedter internal combustion engines nor will I4 will operate model g ad operate models extremely hazardous fuelsfrequencies currently allowed Federal 2 will fly model higher approxi-such containing tetranitromethane orCommunications Commission Only properly Iimately 400 feet within 3 miles airport with-hydrazinecensed Amateurs authorized operate equip- Out notifying airport operator will give right of-way avoid flying proximity full-8 will operate models pyrotechnics anyment Amateur Bsnd frequencies Further scale aircraft necessary observerdevice explodes burns propels projec-any transmitters use sanctioned eveni shall utilized supervise flying avoid hay-tile kind including limited rock-must have certified R/CMA-AMA gold sticker af ing models fly proximity full-scale aircrafteta explosive bombs dropped modelsfixed indicating manufactured modi- U 3 established will abide safety smoke bombs explosive gases such fled operation 20kHz frequency separaeg site use will willfullyhydrogen-filled balloons ground mounted de-lion except 27MHz 53MHzU d de models careless reck-vices launching projectileThe exceptions permitted rockets flown accordance withFREE FLIGHT less and/or dangerous mannerthe Safety Code National Association 4 mode weighs over 20 pounds will onlyRocketry permanently attached per1 will launch mode c aft un ess Ify t n acco dance paragraph 5 sec-JATO use also items authorized Airleast 100 feet downwind spectato auto tion AMA Safety CodeShow Team use defined AST Advisory Coin-mobile parking 5 air shows model flying demonstrations amittee document available AMA HO Note2 will fly model unless launch area single straight line must established sideA model aircraft defined aircraft orclear persons except mechanic offi flying other side spec-without engine able carry human beingcials I tators Only persons essential flight 9 will fly model using turbojet power ax operations permitted flying sideat centrifugal flowi unless have obtained a3 will employ use adequate dev ce n line others must spectatorspecial waiver such specific flights theflight extinguish fuses mode afte de F g spectator side line isAMA President Executive Director willhas completed its function Ip b e beyond control theabide restrictions imposed such flights pilots exceptions may permitby Note does apply ducted fanCONTROL LINE Ited single straight line requirement undermodels using piston engines electric motors special circumstances involving consideration of11 will subject comp m site conditions model size weight speedRADIO CONTROLcluding safety thong applicable inand power must jointly approved AMAspection pull test prior flying President Executive Director maxi-1 twill have completed successful radio equipmum permissible takeoff weight models 55ment ground range check before first flight of21 will assure flying area safely clear Ilbsa new repaired modelof utility wires poles 6 will fly model unless identified with2 will fly model aircraft presence3 will assure fly g a name address AMA number inof spectators until become qualified flier un-of non-essential participants spectators model Note does apply modelsless assisted experienced helperbefore permitting engine started make sure wash out case thoroughly An old toothbrush helps Thoroughly dry oil bearings As stated earlier intake port crankshaft must opened up increase angle remains open Before retiming crank scratch tim ing diagram shown plans onto piece transparent rigid plastic using scribe Thin Plexiglas should work well Insert crankshaft case Slipping drive washer prop nut will help hold shaft proper position Holding engine nose down lay tim ing diagram onto rear engine Line up cross hairs bottom mounting lugs mold flashing centerline engine Referring figure lA rotate shaft un til middle crankpin lines up opening line holding crankshaft position insert hard metal scribe through intake stack make mark crank Use bottom edge frft looking rear side intake port crankcase guide youve set up correctly port should totally closed off shaft doing likewise closing side take port referring figure lB time make mark right side port intake stack can made /2-inOD aluminum nylon brass tubing wall thickness should /32 /16 Wrap Teflon tape around tube ensure good seal intend use remote needle drill tap 6-32 Du-Bro pressure fitting 1/ above stack slips case remote needle made 05 RC needle valve assembly mounted engine bearers using nylon control horn 2-56 sheet metal screws Wash engine parts using hot water dishwashing detergent Dry off parts us ing paper toweling Oil parts WD 40 Break-Free reassemble engine Flying Caudimordax flies best CU line spars using about four five pennies tip weight approximately 13-16 grams Attach streamer test flying Line rake usually set maximum two rearmost holes lead-out guide Brats seem like 7 x 6 Taipan props use 25% Red Max fuel half castor half synthetic oil back-flipping chickenstick technique described Charlie Johnson Combat column seems work best quick starts flying airplane first time check warps Fly level upright note whether either wing appears flying high outboard wing higher inboard very carefully flip airplane onto its back outboard wing flies low have warp still flies high add tip weight outboard wing flies low upright high inverted have warp other way Dont tight turns warped air plane Take home use heat gun shrink covering needed eliminate warp flying against faster opponent use Caudimordaxs superior turning radius advantage Follow opponent through turns advantage level speed negated have actually able fly up others tail pipes occasion Always lookout leading edge kill opponent makes pass streamer often sets him up overshoot thats leading edge kill can ac complished name Caudimordax Doc Passen calls Quasimodo comes Tolkiens book Farmer Giles Ham Naming Combat de signs after weapons named Tolkiens bet ter known book Lord Rings old tra dition Combat circles Orcrist Andu ril English FAI designs instance Glamdring Guthwine Aeglos still up grabs Sting would make good name Anglachel though wouldnt appropriate airplane hope will fly Caudimordax however uniquely appro priate Combat airplane sword also known vulgar tongue Tailbiter habit leaping out its sheath whenever dragon near tra dition time knights kill dra gons cut off tails serve delicacy court sword given Farmer Giles put good use Further development As Combat designs Caudimordax anything static Combat designs evolve faster due high rate destruction Dont afraid try out different airfoils different tail mo ments different construction techniques Per ryman tips Ford Taurus styling Steve Hills Arrowplane wont will can stick Fox 36 nose please use least 34-in-thick wood center block 3/4 x 3A-in maple engine mounts never build Caudimordax article others ought give few ideas improve other design design own Nearly construction techniques used airplane filched others Id like thank too ideas used design Terry Doc Passen foam cutting engine retiming techniques tail hinge bellcrank mount pushrod Phil Cartier arrow-shaft tail boom techniques bladder compartment idea using smaller engines first place Rich ard Wilkens front spar foam cutting bow CL Scale/Boss Continued page 72 Ontario Canada CL Scale judged June 30th flown July 1st Mike reports disappointing CL Scale entry five Two Canadians other three US Its surprising US modelers north central area country werent hand com petition contest site about three hours Buffalo NY about two hours Detroit MI well within days drive several north central statesContinued page 178 December 1990 177 DOE Z2Li2 TNROFILES AND SUPPLIES FOR ELECTRIC FLIGHT SM5 1 6 cells tu u amps SM4 7 23 cells 50 amps Sc6 24 34 cells 60 amps -all throttles linear proportional forward only#15 WiRE 350 STRAND 020 25 size #12 WIRE 665 STRAND 25 100 siz Toas ac4da6ge s 44ff Call write JOMAR 513-474-0985 2028 Knightsbridge Dr. Cincinnati OH 45244
Edition: Model Aviation - 1990/12
Page Numbers: 68, 69, 70, 71, 172, 173, 174, 176, 177
Caudimordax Fast Combat smaller engines works Three ounces fuel can last up five minutes shoulder stays piece slower tight-turning ship gives edge over opponentand engine costs lot less Hlskandar Taib AMERICAN COMBAT design philosophy has traditionally favored speed over turning ability Note large sums money spent Hoffelts custom Foxes bolted onto 300- 400-sq-in airplanes weighing 21 oz What en gines share besides enormous power output weight Most weigh about 9/2 oz Caudimordax design takes other approach high rate turn small turning radius given top priority qualities achieved using light engine high aspect ratio wing compromise speed Caudimordax Brat 28 flies 10 15 mph slower level flight typical Fast Combat job makes up turns though much tighter actually slow down ship much less would heavier model Flying Fast Combat smaller engines has other advantages Three ounces fuel Left left unmodified Brat 28 stIll sporting its RC carburetor author has several give away right modified Brat 28 Note missing metal around exhaust port thinned head fins homemade venturi 7 x 6 Talpal prop Right Close-up view remote needle valve assembly unit OS 10 FSR RC used Note short length tubing slipped over end needle valve prevent leakage plastic clip fuel line available author 68 Model Aviation Author/builder Iskandar Taib holding Caudimordax thoroughly designed Combat plane gives up some top speed typically 10-15 mph makes up barely slowing corners Light weight along special modifications engine make possible Left Mark made crankshaft intake ports closing side Right Mark made opening side Note amount metal has removed Brats have very conservative timing befits its sport RC roots Left Front end tail boom Note shallow cuts made aluminum epoxy grab Small holes may drilled instead Right Engine mount assembly center rib Mount marked sawing using front center rib pattern ft Components horizontal stabilizer Start epoxying arrow shaft stab anchor Glue hinge assembly stab anchor cover horizontal stab -In medium balsa glue stab anchor Right completed tail assembly Notice hinge built String wrapped figure-eight pattern around two 3As dowels December 1990 69 F 4 4 \ - will last five minutes airplane doesnt dislocate shoulder its fast cant keep up slower tight-turning airplane can also hard opponent line up have gotten several kills other guy overshot attack Perhaps important engines cost far less bigger counterparts Caudimordax can also used Out law FAJ contests sprouting up over Midwest Rules typically specify Fast Slow rules 15 engines 52-ft lines no restrictions engine tank setups nitro content fuel Most Schnuerle-ported double ball bear ing 15s weigh about six ounces 34 oz less Brat 28 modifications needed use slightly smaller typically l/ engine bearer spacing mount engine slightly further ward Caudimordax design goes back sev eral years evolving slowly its present form admittedly incorporating features currently vogue External con trols instance now being used top fliers including Russians save much building time allowing use solid wing panels Another great time-saver simple cutout blad der tank replaces common rocket tube arrow-shaft tail boom al though requires little extra building time allows easier rebuilding saves little weight agility Caudimordax attribut able its high aspect ratio wing thick airfoil high aspect ratio reduces tip vortices cause induced drag thick airfoil delays onset high-speed stall thick airfoil also lends lateral sta FAST COMBAT DESIGN ESR 23-32 ENGINES bility design helps control snap rolling associated high aspect ratio designs Induced drag Just what induced drag its reduction important Combat design Drag generally divided two types often confused Parasitic drag caused friction air surface airplane therefore proportional surface area wing Also included category drag lines drag caused protuberances airplane such pushrod engine cylinder Streamlining serves reduce parasitic drag Induced drag other hand re lated lift produced wing wing producing lift pressure air bottom surface wing greater pressure top pressure differences cause air above wings move outward toward wing tips air below wings move toward root tips nothing pre vent air below wings curling around tips pushing down top surface wing reducing actual amount lift produced airflow around wing tip also pro duces turbulent vortices often visible va por trails emanating wing tips jet fighters during high-G maneuvers energy needed drive vortices ulti mately Linked drag drag sociated vortices de scribed induced drag greater lift 70 Model Aviation Pushrod braces made outer Sullivan Ny-Rod Filament tape wraps tail boom bed nails particular piece made out straight section chip-core board Full-Size Plans Available. Page 200 nI 1~ ** TJ / produced wing larger vor tices Several strategies exist reduction tip vortices Tip fences instance will impede air flowing around wing tips Low aspect ratio wings would benefit tip fences Ed Brzys listen ing Theyve seen full-scale air planes low aspect ratio wings such pretty Racing biplane Sorceress Hoer ner anti-vortex tips variation tip fence shaped force airflow tips counter direction tip vor tex However work air plane experiences positive Gs Flip air plane its back anti-vortex tips ac tually add problem Forward sweep wing causes air flow move toward root can spill cause vortex forward swept wings have extremely rigid withstand aeroelastic twisting forces increase wing twists technically known aeroelastic divergence Another way improve efficiency lift/drag ratio wing use smaller wing tip Wind tunnel experiments have shown Schuemann planform shouldnt called George Perryman planform currently vogue glider pi lots has least amount induced drag given amount lift elliptical planform eg Spitfire almost good wing no taper 60% 65% efficient elliptical wing same pect ratio wing tip chord 60% 65% root chord 90% 95% efficient turn tapered wing produces lot less induced drag nontapered High aspect ratio wings have smaller amounts tip spillage low aspect ratio wings less wing tip length per unit area Glider wings have high aspect ratios very purpose High aspect ratio wings have own problems however main being added bending stresses put Continued page 172 Left Cutting top surface wing core Core held tightly board embedded nalis Note bow held Right Cutting spar slot Slot cut single pass down back up Author gives complete directions foam wing cutting something rarely done December 1990 71 / 7- design drawing Nur Iskandar Taib modela fill need hotdog show-off sport plane Knife edge take-offs flat apins snaps anything can Wing foam Fuselage Tail lite ply balsa Builds quick lands like trainer Flyingweight lOlba 184 1 l3lbs 192 Ohio OHIO SUPERSTAR PRODUCTS INC 11376 RIOGEWAY ROADKENSINGTON OHIO 44427 r 216-223-1950 great idea cant resist quoting Mr Stahls comments opening paragraph Overemphasis strictly flying designs con tests throughout country recent years has brought about unwarranted condition ne glect building flying Scale semiscale models Much favoritism must tributed desire maximum performance since little need said relative appearance neatly built Scale ship usual contest design SAM Italia Dr Ferdinando Gale Baveno aly recently sent interesting handbook about Eastern bloc engines written Cesare de Robertis Well illustrated unusual model power plants text Italian available Gale Via Marconi 10 28042 Baveno NO Italy interesting material de signs emerging SAM Italia including several magnificent construction drawings beautiful Italian Gliders pre-WW II era available B2 Streamlines PO Box 976 Olalla WA 98359 RC Pylon/Hager Continued page 64 no mediocre planes event fact well done dont know pilots selected would show two three brought along would still out trying decide Id vote collection absolutely beautiful takeoff area too narrow support four planes up heats threeplane blasts Plans have made things works widen takeoff area fourplane heats can accommodated next spring top 10 finishers Saturday 1 Randy Rich 11480 2 Richard Oliver 11701 3 Red Cranfield 12189 4 Phil Bussell 11742 5 Jim Young 11859 6 Bill Hager 11539 7 Hubert Wills 11905 8 Norm Johnson 11473 9 Dub Jets 11487 10 Sam Womack 11656 Just keep everyones attention two midairs Saturday both occurring just out turn number three Poor Bob Greer par ticipant little high-speed tangos Dave Layman Bill Hager Jerry Small tried trade little paint flight wound up getting planes dirty easier transport under seat Sundays action just hot heavy make sure moves down pat Bob Greer provided present what violent midair collision since vention prop happened about 20 ft di rectly behind above head stood cage turn number pilot lane made clock locked ac tion happened felt bad pilots crash itself right out movies another midair just out turn number three tame comparison Bob Greer/Hubert Wills fiasco earlier com pletely forgot get names pilots volved Yours Truly Bill Hager Jerry SmallBH Top five finishers Sunday 1 Dub Jett 11685 2 Red Cranfield l193 Phil Bussell 12059 4 Bill Hager 11614 5 Montie Montcrief 11620 6 Clay Gary 11509 7 Dave Layman 11381 8 Norm Johnson 11415 9 Randy Ritch 11529 10 Sam Wo mack 12772 Fast time meet 11090 turned Jerry Small lot really good close tight racing action both days can per sonally vouch quality food available heard nothing praise con dition fieldits size its location think two quotes heard often Yall have best racing facilities around grass field absolutely fantastic shape nice words made feel kinda proud field proud have small part core club members come out work event got meet some super-nice guys see some beautiful planes doin some really competitive racing besides Bob Greer Ill long time talking about Sun day midair yours Take guys put first-class race the field great shape See next month Caudimordax/Taib Continued page 71 wing lift being generated farther out root Very high aspect ratio wings demand extra strength conse quently added weight spars root particular application will demand aspect ratio provides best combi nation weight efficiency Cau dimordax aspect ratio 61 cho sen allowed convenient wing span 48 inches Styrofoam comes 2-ftwide sheetsjust right wing panel mean chord eight inches al lows 10-in root 6-in tip 60% tip/root percentage Such wing core too difficult cut trailing edge swept forward three inches lead ing edge swept back inch producing net sweep quarter-chord zero Experiments straight leading edge produced airplanes unpleasant snap rolling tendencies swept leading edge also allows easier placement spars greater lead-out sweep Eliminating high-speed stall Turning airplane too tightly causes wing stall wing forced produce lift capable producing produce lift angle attack must creased Beyond certain angle attack air flow along top wing separates wings surface becomes turbu lent causing sudden increase drag Most Combat fliers adjust controls limit turn radius order avoid stal ling Another approach use thicker blunter airfoil stalls higher Us thin does drawback ap proach course thicker airfoil has greater parasitic drag top speed reduced accordingly Caudimordax root section thick 15% tip thicker 25% relatively thicker tip airfoil ensures root will stall first turn thus reduc ing airplanes tendency drop wing tip tendency causes lateral instabil ity common high aspect ratio Combat wings Longitudinal stability An airplane does tight fast turns absolutely no use cant make go want go common problem Combat wings lack longitudinal stability turn once started will tighten up its own ac cord makes airplane unpointable therefore useless Combat air plane should also able fly straight unattended An unstable airplane will tend tighten wander out turn pilot glances away inslant common misconception sta 172 Model Aviation SPORTOBATIC 2 84 For1204cycleand 902-cycle rST 200025003000-0 PS 18 NEWOS BGX 13500 bilator elevator make airplane move up down true designer could reduce stabilator area airplane thats overly sensitive unstable Actually opposite true stabilator provides stability opposing downward pitching moment produced wing larger stabilizer larger airplanes stability margin since stabilizer doesnt have work hard Similarly longer tail moment increases stability providing longer moment arm stabilizer act Spitfire airplane too small horizontal stabilizer earlier marks had very small acceptable range CG center-of-gravity ad ditional equipment added aft ac ceptable range aircrafts stability de creased fact several structural failures traced directly aircraft tight ened turns due instability Later war longer range fight ers needed long-range bomber es corts CU became issue again way extending Spitfires range especially bigger Griffon engines used later marks situating addi tional tanks behind pilot Eventually larger horizontal vertical stabilizers incorporated allow rear ward center-of-gravity addition larger tail surfaces helped control 2000-plus horsepower output big Griffon engines 12 x 3-in stabilator shown plans Caudimordax longitudinally sta ble will fly large loops want tightening up set up will turn tightly needed point stalling Earlier versions 9 x 3-in tail predictable Construction center rib tip ribs sta bilator lead-out guide bellcrank plate con trol horn engine mount assembly best cut scroll saw band saw en sure accuracy good fit Final shaping can accomplished belt disc sander sure set up tools cut sand perfect 900 angle prefer band saw scroll saw Most scroll saws dont seem have power cut through maple vibration tends obscure guide marks Band saws comparison powerful very smooth can used resawing balsa pine Have ever worked -in pine Slow fuselages cutting alu minum sheet sawing exhaust lugs off engines really nice l0-in-throat three-wheel band saw can obtained Sears little cost Dremel scroll saw Wait until theyre sale can get Christmas Life terrible before got engine mount assembly first glued together very thick CyA cyanoacrylate glue like Special-T What would Combat fliers super glue Make sure grain both balsa spacer 1/64 ply side plates vertical balsa spacer i/ ply plates may look insubstantial two dowels through maple center rib Ive yet have assemblies fail Trial fit engine mark drill holes engine mount assembly must fitted individually its intended center block marking making diagonal cuts maple Remember allow 1/i6 ply front spar Loose-fitting engine mount/center rib combinations can cor rected adding 1/64 ply spacers needed during final assembly aluminum arrow-shaft tail boom can cut length band saw size use 21/64 0D has 019 walls marked 2117 ought avail able good sporting goods store shafts use cutoffs arrows shortened cost quarter Other sizes well graph ite shafts hard come southern Indiana will work just well Use drill press jig some sort drilling hole back cen ter rib Crooked tails get laughed Drill bits available 44-in increments finding right size shouldnt problem Cut notch rear boom us ing band saw Drill two three holes front inch epoxy anchor before gluing boom block together Shallow notches made band saw will work lieu holes Stuff some tissue paper front end boom pre vent epoxy flowing boom Use slow-curing epoxy Make sure notch back end horizontal Cutting foam cores Most Combat con struction articles will tell look else foam cutting instructions method cutting foam first developed Doc Passen easiest method Ive tried yet cutting bow assembled using 1 x 2-in furring strip cutting wire 015 braided control line power source must able supply 12-13 volts 3-4 amps Variac will work does come cheap use car battery Phil Cartier uses light dimmer switch series 200-watt light bulb Write him Core House 760 Waltonville Road Hummelstown PA 17036 details Root tip templates made out -in-thick Formica edges must sanded smooth possible Candle wax rubbed edges also helps straight cuts Note centerline templates 7/ bottom compen sate fact foam rarely exactly two inches thick also 1/16 lost foam cut Put guide marks templates shown both sides well top guiding edge template patterns edge plans make convenient Xeroxing Paste Xeroxed patterns onto Formica cutting surface prepared driving nails through flat piece plywood par ticle board nails serve hold foam down flat during cutting process should penetrate about inch jig should made cutting blanks Two vertical templates needed edge table 27 apart enough space behind accommodate 8-ft -long foam sheets youre really mass production make jigs two feet high cut dozen blanks once Hold layers foam together bam boo shish kebab skewers skewers also useful holding stacks cut wings beds together storage templates held place using double-pointed pins made %-in alumi num brass welding rod Nails December 1990 173 Fly McDaniel Power New Solid State On-Board Glow-Plug Drivers Now can drive 1 2 glow plugs efficiently automatically new McDaniel On-Board Glow-Plug Drivers engine 2 4 stroke glow has 1 2 cylinders Model 471 472 On-Board Glow-Plug Driver will ease jobs starting maintaining idle during taxiing power down flight maneuvers FEATURES INCLUDE Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Connector Plug Battery Pack Remote Glow Plug Indicator Panels Available Separately Battery Pack AC Charger NOT Included Available Separately See Local Hobby Dealer Cantact McDaniel R/C IncVisa MC accepted 1654 Crofton Blvd Suite 4 Crofton MD 21114 e 3017216303 3017216306 NO OCR TEXT r 1 HALFEANLOCK 24 INCHES PATENT PENDING AT LAST positive connector for I HALF glow heads Fits COX glow heads except 020 Two types ring terminals HEAD LOCK/HEAD LITE II adapter ST#050 RING TERM-$595 ST#051 ADAPTER-$695 F IEY AVAILABLE CIDER DIRLT ADD $100 $200 UPSIDE US 12/89 MODEL PRODUCTS CORPORATION POST OFFICE BOX 100 ALLAMUCHY NJ 07820 FAX 201 850 8860 PHONE201 850 1508 IIIWWII AIRCRAFT SCALE DRAWINGS & SPECIFICATION SHEETS Antiques Military CiviIiar Helicopters Saltptanes 2700 ptvs0000 3-view drawirrpIOser 1200 cele FOTO~ K04CU-FANScrIe 3For Csrsisg RANGER FIBERGLASS RANGER FIBERGLASS CO lss bee, Box 879 spesielizirrg ssstorr design nd nrslding Campton NH tire aerospace industry since 1959 03223 S29 Magnum 28 FSR Royal 28 seems well made 25 FSRs far cry earlier Taiwanese engines Its light weight partially due its AAC piston liner As Brat originally intended RC sport flying its induction timing quite con servative Combat use necessary retime induction port replace RC carburetor large-diameter intake stack also known really venturi also helps trim off excess weight head fins dont contribute very much cooling get way changing glow plugs fins can ground off before disassembling engine Remove glow plug plug hole pieces paper toweling Also plug up air intake ex haust Grind off fins using disc belt sander leaving last 3/ intact Wash off filings detergent wa ter before removing paper towel plugs Disassemble engine cylinder liner fits very tightly case must re moved carefully Dont remove bearings Stuff case paper toweling before grinding off muffler lugs Make sure stuff some toweling down exhaust port disc belt sander good way start file can used inaccessible plac es stone Dremel tool also works will clog needs constant dressing Wash filings off detergent water before pulling out paper toweling care filings will enter engine r OFFICIAL AMA SAFETY CODEJanuary 11991 Model Flying Must Accordance Code Order AMA Liability Protection Apply GENERALflown indoors3 will perform initial turn after takeoff away 1 will fly model aircraft competition 7 will operate models metal-bladed pro- tnt spectator areas will there- U after fly over pit speceae U p spectators until has pellers gaseous boosts gases u p oven o rworthy having previ- other sir normal atmospheric pressure en- yond control ous y successfu y flight testedter internal combustion engines nor will I4 will operate model g ad operate models extremely hazardous fuelsfrequencies currently allowed Federal 2 will fly model higher approxi-such containing tetranitromethane orCommunications Commission Only properly Iimately 400 feet within 3 miles airport with-hydrazinecensed Amateurs authorized operate equip- Out notifying airport operator will give right of-way avoid flying proximity full-8 will operate models pyrotechnics anyment Amateur Bsnd frequencies Further scale aircraft necessary observerdevice explodes burns propels projec-any transmitters use sanctioned eveni shall utilized supervise flying avoid hay-tile kind including limited rock-must have certified R/CMA-AMA gold sticker af ing models fly proximity full-scale aircrafteta explosive bombs dropped modelsfixed indicating manufactured modi- U 3 established will abide safety smoke bombs explosive gases such fled operation 20kHz frequency separaeg site use will willfullyhydrogen-filled balloons ground mounted de-lion except 27MHz 53MHzU d de models careless reck-vices launching projectileThe exceptions permitted rockets flown accordance withFREE FLIGHT less and/or dangerous mannerthe Safety Code National Association 4 mode weighs over 20 pounds will onlyRocketry permanently attached per1 will launch mode c aft un ess Ify t n acco dance paragraph 5 sec-JATO use also items authorized Airleast 100 feet downwind spectato auto tion AMA Safety CodeShow Team use defined AST Advisory Coin-mobile parking 5 air shows model flying demonstrations amittee document available AMA HO Note2 will fly model unless launch area single straight line must established sideA model aircraft defined aircraft orclear persons except mechanic offi flying other side spec-without engine able carry human beingcials I tators Only persons essential flight 9 will fly model using turbojet power ax operations permitted flying sideat centrifugal flowi unless have obtained a3 will employ use adequate dev ce n line others must spectatorspecial waiver such specific flights theflight extinguish fuses mode afte de F g spectator side line isAMA President Executive Director willhas completed its function Ip b e beyond control theabide restrictions imposed such flights pilots exceptions may permitby Note does apply ducted fanCONTROL LINE Ited single straight line requirement undermodels using piston engines electric motors special circumstances involving consideration of11 will subject comp m site conditions model size weight speedRADIO CONTROLcluding safety thong applicable inand power must jointly approved AMAspection pull test prior flying President Executive Director maxi-1 twill have completed successful radio equipmum permissible takeoff weight models 55ment ground range check before first flight of21 will assure flying area safely clear Ilbsa new repaired modelof utility wires poles 6 will fly model unless identified with2 will fly model aircraft presence3 will assure fly g a name address AMA number inof spectators until become qualified flier un-of non-essential participants spectators model Note does apply modelsless assisted experienced helperbefore permitting engine started make sure wash out case thoroughly An old toothbrush helps Thoroughly dry oil bearings As stated earlier intake port crankshaft must opened up increase angle remains open Before retiming crank scratch tim ing diagram shown plans onto piece transparent rigid plastic using scribe Thin Plexiglas should work well Insert crankshaft case Slipping drive washer prop nut will help hold shaft proper position Holding engine nose down lay tim ing diagram onto rear engine Line up cross hairs bottom mounting lugs mold flashing centerline engine Referring figure lA rotate shaft un til middle crankpin lines up opening line holding crankshaft position insert hard metal scribe through intake stack make mark crank Use bottom edge frft looking rear side intake port crankcase guide youve set up correctly port should totally closed off shaft doing likewise closing side take port referring figure lB time make mark right side port intake stack can made /2-inOD aluminum nylon brass tubing wall thickness should /32 /16 Wrap Teflon tape around tube ensure good seal intend use remote needle drill tap 6-32 Du-Bro pressure fitting 1/ above stack slips case remote needle made 05 RC needle valve assembly mounted engine bearers using nylon control horn 2-56 sheet metal screws Wash engine parts using hot water dishwashing detergent Dry off parts us ing paper toweling Oil parts WD 40 Break-Free reassemble engine Flying Caudimordax flies best CU line spars using about four five pennies tip weight approximately 13-16 grams Attach streamer test flying Line rake usually set maximum two rearmost holes lead-out guide Brats seem like 7 x 6 Taipan props use 25% Red Max fuel half castor half synthetic oil back-flipping chickenstick technique described Charlie Johnson Combat column seems work best quick starts flying airplane first time check warps Fly level upright note whether either wing appears flying high outboard wing higher inboard very carefully flip airplane onto its back outboard wing flies low have warp still flies high add tip weight outboard wing flies low upright high inverted have warp other way Dont tight turns warped air plane Take home use heat gun shrink covering needed eliminate warp flying against faster opponent use Caudimordaxs superior turning radius advantage Follow opponent through turns advantage level speed negated have actually able fly up others tail pipes occasion Always lookout leading edge kill opponent makes pass streamer often sets him up overshoot thats leading edge kill can ac complished name Caudimordax Doc Passen calls Quasimodo comes Tolkiens book Farmer Giles Ham Naming Combat de signs after weapons named Tolkiens bet ter known book Lord Rings old tra dition Combat circles Orcrist Andu ril English FAI designs instance Glamdring Guthwine Aeglos still up grabs Sting would make good name Anglachel though wouldnt appropriate airplane hope will fly Caudimordax however uniquely appro priate Combat airplane sword also known vulgar tongue Tailbiter habit leaping out its sheath whenever dragon near tra dition time knights kill dra gons cut off tails serve delicacy court sword given Farmer Giles put good use Further development As Combat designs Caudimordax anything static Combat designs evolve faster due high rate destruction Dont afraid try out different airfoils different tail mo ments different construction techniques Per ryman tips Ford Taurus styling Steve Hills Arrowplane wont will can stick Fox 36 nose please use least 34-in-thick wood center block 3/4 x 3A-in maple engine mounts never build Caudimordax article others ought give few ideas improve other design design own Nearly construction techniques used airplane filched others Id like thank too ideas used design Terry Doc Passen foam cutting engine retiming techniques tail hinge bellcrank mount pushrod Phil Cartier arrow-shaft tail boom techniques bladder compartment idea using smaller engines first place Rich ard Wilkens front spar foam cutting bow CL Scale/Boss Continued page 72 Ontario Canada CL Scale judged June 30th flown July 1st Mike reports disappointing CL Scale entry five Two Canadians other three US Its surprising US modelers north central area country werent hand com petition contest site about three hours Buffalo NY about two hours Detroit MI well within days drive several north central statesContinued page 178 December 1990 177 DOE Z2Li2 TNROFILES AND SUPPLIES FOR ELECTRIC FLIGHT SM5 1 6 cells tu u amps SM4 7 23 cells 50 amps Sc6 24 34 cells 60 amps -all throttles linear proportional forward only#15 WiRE 350 STRAND 020 25 size #12 WIRE 665 STRAND 25 100 siz Toas ac4da6ge s 44ff Call write JOMAR 513-474-0985 2028 Knightsbridge Dr. Cincinnati OH 45244
Edition: Model Aviation - 1990/12
Page Numbers: 68, 69, 70, 71, 172, 173, 174, 176, 177
Caudimordax Fast Combat smaller engines works Three ounces fuel can last up five minutes shoulder stays piece slower tight-turning ship gives edge over opponentand engine costs lot less Hlskandar Taib AMERICAN COMBAT design philosophy has traditionally favored speed over turning ability Note large sums money spent Hoffelts custom Foxes bolted onto 300- 400-sq-in airplanes weighing 21 oz What en gines share besides enormous power output weight Most weigh about 9/2 oz Caudimordax design takes other approach high rate turn small turning radius given top priority qualities achieved using light engine high aspect ratio wing compromise speed Caudimordax Brat 28 flies 10 15 mph slower level flight typical Fast Combat job makes up turns though much tighter actually slow down ship much less would heavier model Flying Fast Combat smaller engines has other advantages Three ounces fuel Left left unmodified Brat 28 stIll sporting its RC carburetor author has several give away right modified Brat 28 Note missing metal around exhaust port thinned head fins homemade venturi 7 x 6 Talpal prop Right Close-up view remote needle valve assembly unit OS 10 FSR RC used Note short length tubing slipped over end needle valve prevent leakage plastic clip fuel line available author 68 Model Aviation Author/builder Iskandar Taib holding Caudimordax thoroughly designed Combat plane gives up some top speed typically 10-15 mph makes up barely slowing corners Light weight along special modifications engine make possible Left Mark made crankshaft intake ports closing side Right Mark made opening side Note amount metal has removed Brats have very conservative timing befits its sport RC roots Left Front end tail boom Note shallow cuts made aluminum epoxy grab Small holes may drilled instead Right Engine mount assembly center rib Mount marked sawing using front center rib pattern ft Components horizontal stabilizer Start epoxying arrow shaft stab anchor Glue hinge assembly stab anchor cover horizontal stab -In medium balsa glue stab anchor Right completed tail assembly Notice hinge built String wrapped figure-eight pattern around two 3As dowels December 1990 69 F 4 4 \ - will last five minutes airplane doesnt dislocate shoulder its fast cant keep up slower tight-turning airplane can also hard opponent line up have gotten several kills other guy overshot attack Perhaps important engines cost far less bigger counterparts Caudimordax can also used Out law FAJ contests sprouting up over Midwest Rules typically specify Fast Slow rules 15 engines 52-ft lines no restrictions engine tank setups nitro content fuel Most Schnuerle-ported double ball bear ing 15s weigh about six ounces 34 oz less Brat 28 modifications needed use slightly smaller typically l/ engine bearer spacing mount engine slightly further ward Caudimordax design goes back sev eral years evolving slowly its present form admittedly incorporating features currently vogue External con trols instance now being used top fliers including Russians save much building time allowing use solid wing panels Another great time-saver simple cutout blad der tank replaces common rocket tube arrow-shaft tail boom al though requires little extra building time allows easier rebuilding saves little weight agility Caudimordax attribut able its high aspect ratio wing thick airfoil high aspect ratio reduces tip vortices cause induced drag thick airfoil delays onset high-speed stall thick airfoil also lends lateral sta FAST COMBAT DESIGN ESR 23-32 ENGINES bility design helps control snap rolling associated high aspect ratio designs Induced drag Just what induced drag its reduction important Combat design Drag generally divided two types often confused Parasitic drag caused friction air surface airplane therefore proportional surface area wing Also included category drag lines drag caused protuberances airplane such pushrod engine cylinder Streamlining serves reduce parasitic drag Induced drag other hand re lated lift produced wing wing producing lift pressure air bottom surface wing greater pressure top pressure differences cause air above wings move outward toward wing tips air below wings move toward root tips nothing pre vent air below wings curling around tips pushing down top surface wing reducing actual amount lift produced airflow around wing tip also pro duces turbulent vortices often visible va por trails emanating wing tips jet fighters during high-G maneuvers energy needed drive vortices ulti mately Linked drag drag sociated vortices de scribed induced drag greater lift 70 Model Aviation Pushrod braces made outer Sullivan Ny-Rod Filament tape wraps tail boom bed nails particular piece made out straight section chip-core board Full-Size Plans Available. Page 200 nI 1~ ** TJ / produced wing larger vor tices Several strategies exist reduction tip vortices Tip fences instance will impede air flowing around wing tips Low aspect ratio wings would benefit tip fences Ed Brzys listen ing Theyve seen full-scale air planes low aspect ratio wings such pretty Racing biplane Sorceress Hoer ner anti-vortex tips variation tip fence shaped force airflow tips counter direction tip vor tex However work air plane experiences positive Gs Flip air plane its back anti-vortex tips ac tually add problem Forward sweep wing causes air flow move toward root can spill cause vortex forward swept wings have extremely rigid withstand aeroelastic twisting forces increase wing twists technically known aeroelastic divergence Another way improve efficiency lift/drag ratio wing use smaller wing tip Wind tunnel experiments have shown Schuemann planform shouldnt called George Perryman planform currently vogue glider pi lots has least amount induced drag given amount lift elliptical planform eg Spitfire almost good wing no taper 60% 65% efficient elliptical wing same pect ratio wing tip chord 60% 65% root chord 90% 95% efficient turn tapered wing produces lot less induced drag nontapered High aspect ratio wings have smaller amounts tip spillage low aspect ratio wings less wing tip length per unit area Glider wings have high aspect ratios very purpose High aspect ratio wings have own problems however main being added bending stresses put Continued page 172 Left Cutting top surface wing core Core held tightly board embedded nalis Note bow held Right Cutting spar slot Slot cut single pass down back up Author gives complete directions foam wing cutting something rarely done December 1990 71 / 7- design drawing Nur Iskandar Taib modela fill need hotdog show-off sport plane Knife edge take-offs flat apins snaps anything can Wing foam Fuselage Tail lite ply balsa Builds quick lands like trainer Flyingweight lOlba 184 1 l3lbs 192 Ohio OHIO SUPERSTAR PRODUCTS INC 11376 RIOGEWAY ROADKENSINGTON OHIO 44427 r 216-223-1950 great idea cant resist quoting Mr Stahls comments opening paragraph Overemphasis strictly flying designs con tests throughout country recent years has brought about unwarranted condition ne glect building flying Scale semiscale models Much favoritism must tributed desire maximum performance since little need said relative appearance neatly built Scale ship usual contest design SAM Italia Dr Ferdinando Gale Baveno aly recently sent interesting handbook about Eastern bloc engines written Cesare de Robertis Well illustrated unusual model power plants text Italian available Gale Via Marconi 10 28042 Baveno NO Italy interesting material de signs emerging SAM Italia including several magnificent construction drawings beautiful Italian Gliders pre-WW II era available B2 Streamlines PO Box 976 Olalla WA 98359 RC Pylon/Hager Continued page 64 no mediocre planes event fact well done dont know pilots selected would show two three brought along would still out trying decide Id vote collection absolutely beautiful takeoff area too narrow support four planes up heats threeplane blasts Plans have made things works widen takeoff area fourplane heats can accommodated next spring top 10 finishers Saturday 1 Randy Rich 11480 2 Richard Oliver 11701 3 Red Cranfield 12189 4 Phil Bussell 11742 5 Jim Young 11859 6 Bill Hager 11539 7 Hubert Wills 11905 8 Norm Johnson 11473 9 Dub Jets 11487 10 Sam Womack 11656 Just keep everyones attention two midairs Saturday both occurring just out turn number three Poor Bob Greer par ticipant little high-speed tangos Dave Layman Bill Hager Jerry Small tried trade little paint flight wound up getting planes dirty easier transport under seat Sundays action just hot heavy make sure moves down pat Bob Greer provided present what violent midair collision since vention prop happened about 20 ft di rectly behind above head stood cage turn number pilot lane made clock locked ac tion happened felt bad pilots crash itself right out movies another midair just out turn number three tame comparison Bob Greer/Hubert Wills fiasco earlier com pletely forgot get names pilots volved Yours Truly Bill Hager Jerry SmallBH Top five finishers Sunday 1 Dub Jett 11685 2 Red Cranfield l193 Phil Bussell 12059 4 Bill Hager 11614 5 Montie Montcrief 11620 6 Clay Gary 11509 7 Dave Layman 11381 8 Norm Johnson 11415 9 Randy Ritch 11529 10 Sam Wo mack 12772 Fast time meet 11090 turned Jerry Small lot really good close tight racing action both days can per sonally vouch quality food available heard nothing praise con dition fieldits size its location think two quotes heard often Yall have best racing facilities around grass field absolutely fantastic shape nice words made feel kinda proud field proud have small part core club members come out work event got meet some super-nice guys see some beautiful planes doin some really competitive racing besides Bob Greer Ill long time talking about Sun day midair yours Take guys put first-class race the field great shape See next month Caudimordax/Taib Continued page 71 wing lift being generated farther out root Very high aspect ratio wings demand extra strength conse quently added weight spars root particular application will demand aspect ratio provides best combi nation weight efficiency Cau dimordax aspect ratio 61 cho sen allowed convenient wing span 48 inches Styrofoam comes 2-ftwide sheetsjust right wing panel mean chord eight inches al lows 10-in root 6-in tip 60% tip/root percentage Such wing core too difficult cut trailing edge swept forward three inches lead ing edge swept back inch producing net sweep quarter-chord zero Experiments straight leading edge produced airplanes unpleasant snap rolling tendencies swept leading edge also allows easier placement spars greater lead-out sweep Eliminating high-speed stall Turning airplane too tightly causes wing stall wing forced produce lift capable producing produce lift angle attack must creased Beyond certain angle attack air flow along top wing separates wings surface becomes turbu lent causing sudden increase drag Most Combat fliers adjust controls limit turn radius order avoid stal ling Another approach use thicker blunter airfoil stalls higher Us thin does drawback ap proach course thicker airfoil has greater parasitic drag top speed reduced accordingly Caudimordax root section thick 15% tip thicker 25% relatively thicker tip airfoil ensures root will stall first turn thus reduc ing airplanes tendency drop wing tip tendency causes lateral instabil ity common high aspect ratio Combat wings Longitudinal stability An airplane does tight fast turns absolutely no use cant make go want go common problem Combat wings lack longitudinal stability turn once started will tighten up its own ac cord makes airplane unpointable therefore useless Combat air plane should also able fly straight unattended An unstable airplane will tend tighten wander out turn pilot glances away inslant common misconception sta 172 Model Aviation SPORTOBATIC 2 84 For1204cycleand 902-cycle rST 200025003000-0 PS 18 NEWOS BGX 13500 bilator elevator make airplane move up down true designer could reduce stabilator area airplane thats overly sensitive unstable Actually opposite true stabilator provides stability opposing downward pitching moment produced wing larger stabilizer larger airplanes stability margin since stabilizer doesnt have work hard Similarly longer tail moment increases stability providing longer moment arm stabilizer act Spitfire airplane too small horizontal stabilizer earlier marks had very small acceptable range CG center-of-gravity ad ditional equipment added aft ac ceptable range aircrafts stability de creased fact several structural failures traced directly aircraft tight ened turns due instability Later war longer range fight ers needed long-range bomber es corts CU became issue again way extending Spitfires range especially bigger Griffon engines used later marks situating addi tional tanks behind pilot Eventually larger horizontal vertical stabilizers incorporated allow rear ward center-of-gravity addition larger tail surfaces helped control 2000-plus horsepower output big Griffon engines 12 x 3-in stabilator shown plans Caudimordax longitudinally sta ble will fly large loops want tightening up set up will turn tightly needed point stalling Earlier versions 9 x 3-in tail predictable Construction center rib tip ribs sta bilator lead-out guide bellcrank plate con trol horn engine mount assembly best cut scroll saw band saw en sure accuracy good fit Final shaping can accomplished belt disc sander sure set up tools cut sand perfect 900 angle prefer band saw scroll saw Most scroll saws dont seem have power cut through maple vibration tends obscure guide marks Band saws comparison powerful very smooth can used resawing balsa pine Have ever worked -in pine Slow fuselages cutting alu minum sheet sawing exhaust lugs off engines really nice l0-in-throat three-wheel band saw can obtained Sears little cost Dremel scroll saw Wait until theyre sale can get Christmas Life terrible before got engine mount assembly first glued together very thick CyA cyanoacrylate glue like Special-T What would Combat fliers super glue Make sure grain both balsa spacer 1/64 ply side plates vertical balsa spacer i/ ply plates may look insubstantial two dowels through maple center rib Ive yet have assemblies fail Trial fit engine mark drill holes engine mount assembly must fitted individually its intended center block marking making diagonal cuts maple Remember allow 1/i6 ply front spar Loose-fitting engine mount/center rib combinations can cor rected adding 1/64 ply spacers needed during final assembly aluminum arrow-shaft tail boom can cut length band saw size use 21/64 0D has 019 walls marked 2117 ought avail able good sporting goods store shafts use cutoffs arrows shortened cost quarter Other sizes well graph ite shafts hard come southern Indiana will work just well Use drill press jig some sort drilling hole back cen ter rib Crooked tails get laughed Drill bits available 44-in increments finding right size shouldnt problem Cut notch rear boom us ing band saw Drill two three holes front inch epoxy anchor before gluing boom block together Shallow notches made band saw will work lieu holes Stuff some tissue paper front end boom pre vent epoxy flowing boom Use slow-curing epoxy Make sure notch back end horizontal Cutting foam cores Most Combat con struction articles will tell look else foam cutting instructions method cutting foam first developed Doc Passen easiest method Ive tried yet cutting bow assembled using 1 x 2-in furring strip cutting wire 015 braided control line power source must able supply 12-13 volts 3-4 amps Variac will work does come cheap use car battery Phil Cartier uses light dimmer switch series 200-watt light bulb Write him Core House 760 Waltonville Road Hummelstown PA 17036 details Root tip templates made out -in-thick Formica edges must sanded smooth possible Candle wax rubbed edges also helps straight cuts Note centerline templates 7/ bottom compen sate fact foam rarely exactly two inches thick also 1/16 lost foam cut Put guide marks templates shown both sides well top guiding edge template patterns edge plans make convenient Xeroxing Paste Xeroxed patterns onto Formica cutting surface prepared driving nails through flat piece plywood par ticle board nails serve hold foam down flat during cutting process should penetrate about inch jig should made cutting blanks Two vertical templates needed edge table 27 apart enough space behind accommodate 8-ft -long foam sheets youre really mass production make jigs two feet high cut dozen blanks once Hold layers foam together bam boo shish kebab skewers skewers also useful holding stacks cut wings beds together storage templates held place using double-pointed pins made %-in alumi num brass welding rod Nails December 1990 173 Fly McDaniel Power New Solid State On-Board Glow-Plug Drivers Now can drive 1 2 glow plugs efficiently automatically new McDaniel On-Board Glow-Plug Drivers engine 2 4 stroke glow has 1 2 cylinders Model 471 472 On-Board Glow-Plug Driver will ease jobs starting maintaining idle during taxiing power down flight maneuvers FEATURES INCLUDE Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Connector Plug Battery Pack Remote Glow Plug Indicator Panels Available Separately Battery Pack AC Charger NOT Included Available Separately See Local Hobby Dealer Cantact McDaniel R/C IncVisa MC accepted 1654 Crofton Blvd Suite 4 Crofton MD 21114 e 3017216303 3017216306 NO OCR TEXT r 1 HALFEANLOCK 24 INCHES PATENT PENDING AT LAST positive connector for I HALF glow heads Fits COX glow heads except 020 Two types ring terminals HEAD LOCK/HEAD LITE II adapter ST#050 RING TERM-$595 ST#051 ADAPTER-$695 F IEY AVAILABLE CIDER DIRLT ADD $100 $200 UPSIDE US 12/89 MODEL PRODUCTS CORPORATION POST OFFICE BOX 100 ALLAMUCHY NJ 07820 FAX 201 850 8860 PHONE201 850 1508 IIIWWII AIRCRAFT SCALE DRAWINGS & SPECIFICATION SHEETS Antiques Military CiviIiar Helicopters Saltptanes 2700 ptvs0000 3-view drawirrpIOser 1200 cele FOTO~ K04CU-FANScrIe 3For Csrsisg RANGER FIBERGLASS RANGER FIBERGLASS CO lss bee, Box 879 spesielizirrg ssstorr design nd nrslding Campton NH tire aerospace industry since 1959 03223 S29 Magnum 28 FSR Royal 28 seems well made 25 FSRs far cry earlier Taiwanese engines Its light weight partially due its AAC piston liner As Brat originally intended RC sport flying its induction timing quite con servative Combat use necessary retime induction port replace RC carburetor large-diameter intake stack also known really venturi also helps trim off excess weight head fins dont contribute very much cooling get way changing glow plugs fins can ground off before disassembling engine Remove glow plug plug hole pieces paper toweling Also plug up air intake ex haust Grind off fins using disc belt sander leaving last 3/ intact Wash off filings detergent wa ter before removing paper towel plugs Disassemble engine cylinder liner fits very tightly case must re moved carefully Dont remove bearings Stuff case paper toweling before grinding off muffler lugs Make sure stuff some toweling down exhaust port disc belt sander good way start file can used inaccessible plac es stone Dremel tool also works will clog needs constant dressing Wash filings off detergent water before pulling out paper toweling care filings will enter engine r OFFICIAL AMA SAFETY CODEJanuary 11991 Model Flying Must Accordance Code Order AMA Liability Protection Apply GENERALflown indoors3 will perform initial turn after takeoff away 1 will fly model aircraft competition 7 will operate models metal-bladed pro- tnt spectator areas will there- U after fly over pit speceae U p spectators until has pellers gaseous boosts gases u p oven o rworthy having previ- other sir normal atmospheric pressure en- yond control ous y successfu y flight testedter internal combustion engines nor will I4 will operate model g ad operate models extremely hazardous fuelsfrequencies currently allowed Federal 2 will fly model higher approxi-such containing tetranitromethane orCommunications Commission Only properly Iimately 400 feet within 3 miles airport with-hydrazinecensed Amateurs authorized operate equip- Out notifying airport operator will give right of-way avoid flying proximity full-8 will operate models pyrotechnics anyment Amateur Bsnd frequencies Further scale aircraft necessary observerdevice explodes burns propels projec-any transmitters use sanctioned eveni shall utilized supervise flying avoid hay-tile kind including limited rock-must have certified R/CMA-AMA gold sticker af ing models fly proximity full-scale aircrafteta explosive bombs dropped modelsfixed indicating manufactured modi- U 3 established will abide safety smoke bombs explosive gases such fled operation 20kHz frequency separaeg site use will willfullyhydrogen-filled balloons ground mounted de-lion except 27MHz 53MHzU d de models careless reck-vices launching projectileThe exceptions permitted rockets flown accordance withFREE FLIGHT less and/or dangerous mannerthe Safety Code National Association 4 mode weighs over 20 pounds will onlyRocketry permanently attached per1 will launch mode c aft un ess Ify t n acco dance paragraph 5 sec-JATO use also items authorized Airleast 100 feet downwind spectato auto tion AMA Safety CodeShow Team use defined AST Advisory Coin-mobile parking 5 air shows model flying demonstrations amittee document available AMA HO Note2 will fly model unless launch area single straight line must established sideA model aircraft defined aircraft orclear persons except mechanic offi flying other side spec-without engine able carry human beingcials I tators Only persons essential flight 9 will fly model using turbojet power ax operations permitted flying sideat centrifugal flowi unless have obtained a3 will employ use adequate dev ce n line others must spectatorspecial waiver such specific flights theflight extinguish fuses mode afte de F g spectator side line isAMA President Executive Director willhas completed its function Ip b e beyond control theabide restrictions imposed such flights pilots exceptions may permitby Note does apply ducted fanCONTROL LINE Ited single straight line requirement undermodels using piston engines electric motors special circumstances involving consideration of11 will subject comp m site conditions model size weight speedRADIO CONTROLcluding safety thong applicable inand power must jointly approved AMAspection pull test prior flying President Executive Director maxi-1 twill have completed successful radio equipmum permissible takeoff weight models 55ment ground range check before first flight of21 will assure flying area safely clear Ilbsa new repaired modelof utility wires poles 6 will fly model unless identified with2 will fly model aircraft presence3 will assure fly g a name address AMA number inof spectators until become qualified flier un-of non-essential participants spectators model Note does apply modelsless assisted experienced helperbefore permitting engine started make sure wash out case thoroughly An old toothbrush helps Thoroughly dry oil bearings As stated earlier intake port crankshaft must opened up increase angle remains open Before retiming crank scratch tim ing diagram shown plans onto piece transparent rigid plastic using scribe Thin Plexiglas should work well Insert crankshaft case Slipping drive washer prop nut will help hold shaft proper position Holding engine nose down lay tim ing diagram onto rear engine Line up cross hairs bottom mounting lugs mold flashing centerline engine Referring figure lA rotate shaft un til middle crankpin lines up opening line holding crankshaft position insert hard metal scribe through intake stack make mark crank Use bottom edge frft looking rear side intake port crankcase guide youve set up correctly port should totally closed off shaft doing likewise closing side take port referring figure lB time make mark right side port intake stack can made /2-inOD aluminum nylon brass tubing wall thickness should /32 /16 Wrap Teflon tape around tube ensure good seal intend use remote needle drill tap 6-32 Du-Bro pressure fitting 1/ above stack slips case remote needle made 05 RC needle valve assembly mounted engine bearers using nylon control horn 2-56 sheet metal screws Wash engine parts using hot water dishwashing detergent Dry off parts us ing paper toweling Oil parts WD 40 Break-Free reassemble engine Flying Caudimordax flies best CU line spars using about four five pennies tip weight approximately 13-16 grams Attach streamer test flying Line rake usually set maximum two rearmost holes lead-out guide Brats seem like 7 x 6 Taipan props use 25% Red Max fuel half castor half synthetic oil back-flipping chickenstick technique described Charlie Johnson Combat column seems work best quick starts flying airplane first time check warps Fly level upright note whether either wing appears flying high outboard wing higher inboard very carefully flip airplane onto its back outboard wing flies low have warp still flies high add tip weight outboard wing flies low upright high inverted have warp other way Dont tight turns warped air plane Take home use heat gun shrink covering needed eliminate warp flying against faster opponent use Caudimordaxs superior turning radius advantage Follow opponent through turns advantage level speed negated have actually able fly up others tail pipes occasion Always lookout leading edge kill opponent makes pass streamer often sets him up overshoot thats leading edge kill can ac complished name Caudimordax Doc Passen calls Quasimodo comes Tolkiens book Farmer Giles Ham Naming Combat de signs after weapons named Tolkiens bet ter known book Lord Rings old tra dition Combat circles Orcrist Andu ril English FAI designs instance Glamdring Guthwine Aeglos still up grabs Sting would make good name Anglachel though wouldnt appropriate airplane hope will fly Caudimordax however uniquely appro priate Combat airplane sword also known vulgar tongue Tailbiter habit leaping out its sheath whenever dragon near tra dition time knights kill dra gons cut off tails serve delicacy court sword given Farmer Giles put good use Further development As Combat designs Caudimordax anything static Combat designs evolve faster due high rate destruction Dont afraid try out different airfoils different tail mo ments different construction techniques Per ryman tips Ford Taurus styling Steve Hills Arrowplane wont will can stick Fox 36 nose please use least 34-in-thick wood center block 3/4 x 3A-in maple engine mounts never build Caudimordax article others ought give few ideas improve other design design own Nearly construction techniques used airplane filched others Id like thank too ideas used design Terry Doc Passen foam cutting engine retiming techniques tail hinge bellcrank mount pushrod Phil Cartier arrow-shaft tail boom techniques bladder compartment idea using smaller engines first place Rich ard Wilkens front spar foam cutting bow CL Scale/Boss Continued page 72 Ontario Canada CL Scale judged June 30th flown July 1st Mike reports disappointing CL Scale entry five Two Canadians other three US Its surprising US modelers north central area country werent hand com petition contest site about three hours Buffalo NY about two hours Detroit MI well within days drive several north central statesContinued page 178 December 1990 177 DOE Z2Li2 TNROFILES AND SUPPLIES FOR ELECTRIC FLIGHT SM5 1 6 cells tu u amps SM4 7 23 cells 50 amps Sc6 24 34 cells 60 amps -all throttles linear proportional forward only#15 WiRE 350 STRAND 020 25 size #12 WIRE 665 STRAND 25 100 siz Toas ac4da6ge s 44ff Call write JOMAR 513-474-0985 2028 Knightsbridge Dr. Cincinnati OH 45244
Edition: Model Aviation - 1990/12
Page Numbers: 68, 69, 70, 71, 172, 173, 174, 176, 177
Caudimordax Fast Combat smaller engines works Three ounces fuel can last up five minutes shoulder stays piece slower tight-turning ship gives edge over opponentand engine costs lot less Hlskandar Taib AMERICAN COMBAT design philosophy has traditionally favored speed over turning ability Note large sums money spent Hoffelts custom Foxes bolted onto 300- 400-sq-in airplanes weighing 21 oz What en gines share besides enormous power output weight Most weigh about 9/2 oz Caudimordax design takes other approach high rate turn small turning radius given top priority qualities achieved using light engine high aspect ratio wing compromise speed Caudimordax Brat 28 flies 10 15 mph slower level flight typical Fast Combat job makes up turns though much tighter actually slow down ship much less would heavier model Flying Fast Combat smaller engines has other advantages Three ounces fuel Left left unmodified Brat 28 stIll sporting its RC carburetor author has several give away right modified Brat 28 Note missing metal around exhaust port thinned head fins homemade venturi 7 x 6 Talpal prop Right Close-up view remote needle valve assembly unit OS 10 FSR RC used Note short length tubing slipped over end needle valve prevent leakage plastic clip fuel line available author 68 Model Aviation Author/builder Iskandar Taib holding Caudimordax thoroughly designed Combat plane gives up some top speed typically 10-15 mph makes up barely slowing corners Light weight along special modifications engine make possible Left Mark made crankshaft intake ports closing side Right Mark made opening side Note amount metal has removed Brats have very conservative timing befits its sport RC roots Left Front end tail boom Note shallow cuts made aluminum epoxy grab Small holes may drilled instead Right Engine mount assembly center rib Mount marked sawing using front center rib pattern ft Components horizontal stabilizer Start epoxying arrow shaft stab anchor Glue hinge assembly stab anchor cover horizontal stab -In medium balsa glue stab anchor Right completed tail assembly Notice hinge built String wrapped figure-eight pattern around two 3As dowels December 1990 69 F 4 4 \ - will last five minutes airplane doesnt dislocate shoulder its fast cant keep up slower tight-turning airplane can also hard opponent line up have gotten several kills other guy overshot attack Perhaps important engines cost far less bigger counterparts Caudimordax can also used Out law FAJ contests sprouting up over Midwest Rules typically specify Fast Slow rules 15 engines 52-ft lines no restrictions engine tank setups nitro content fuel Most Schnuerle-ported double ball bear ing 15s weigh about six ounces 34 oz less Brat 28 modifications needed use slightly smaller typically l/ engine bearer spacing mount engine slightly further ward Caudimordax design goes back sev eral years evolving slowly its present form admittedly incorporating features currently vogue External con trols instance now being used top fliers including Russians save much building time allowing use solid wing panels Another great time-saver simple cutout blad der tank replaces common rocket tube arrow-shaft tail boom al though requires little extra building time allows easier rebuilding saves little weight agility Caudimordax attribut able its high aspect ratio wing thick airfoil high aspect ratio reduces tip vortices cause induced drag thick airfoil delays onset high-speed stall thick airfoil also lends lateral sta FAST COMBAT DESIGN ESR 23-32 ENGINES bility design helps control snap rolling associated high aspect ratio designs Induced drag Just what induced drag its reduction important Combat design Drag generally divided two types often confused Parasitic drag caused friction air surface airplane therefore proportional surface area wing Also included category drag lines drag caused protuberances airplane such pushrod engine cylinder Streamlining serves reduce parasitic drag Induced drag other hand re lated lift produced wing wing producing lift pressure air bottom surface wing greater pressure top pressure differences cause air above wings move outward toward wing tips air below wings move toward root tips nothing pre vent air below wings curling around tips pushing down top surface wing reducing actual amount lift produced airflow around wing tip also pro duces turbulent vortices often visible va por trails emanating wing tips jet fighters during high-G maneuvers energy needed drive vortices ulti mately Linked drag drag sociated vortices de scribed induced drag greater lift 70 Model Aviation Pushrod braces made outer Sullivan Ny-Rod Filament tape wraps tail boom bed nails particular piece made out straight section chip-core board Full-Size Plans Available. Page 200 nI 1~ ** TJ / produced wing larger vor tices Several strategies exist reduction tip vortices Tip fences instance will impede air flowing around wing tips Low aspect ratio wings would benefit tip fences Ed Brzys listen ing Theyve seen full-scale air planes low aspect ratio wings such pretty Racing biplane Sorceress Hoer ner anti-vortex tips variation tip fence shaped force airflow tips counter direction tip vor tex However work air plane experiences positive Gs Flip air plane its back anti-vortex tips ac tually add problem Forward sweep wing causes air flow move toward root can spill cause vortex forward swept wings have extremely rigid withstand aeroelastic twisting forces increase wing twists technically known aeroelastic divergence Another way improve efficiency lift/drag ratio wing use smaller wing tip Wind tunnel experiments have shown Schuemann planform shouldnt called George Perryman planform currently vogue glider pi lots has least amount induced drag given amount lift elliptical planform eg Spitfire almost good wing no taper 60% 65% efficient elliptical wing same pect ratio wing tip chord 60% 65% root chord 90% 95% efficient turn tapered wing produces lot less induced drag nontapered High aspect ratio wings have smaller amounts tip spillage low aspect ratio wings less wing tip length per unit area Glider wings have high aspect ratios very purpose High aspect ratio wings have own problems however main being added bending stresses put Continued page 172 Left Cutting top surface wing core Core held tightly board embedded nalis Note bow held Right Cutting spar slot Slot cut single pass down back up Author gives complete directions foam wing cutting something rarely done December 1990 71 / 7- design drawing Nur Iskandar Taib modela fill need hotdog show-off sport plane Knife edge take-offs flat apins snaps anything can Wing foam Fuselage Tail lite ply balsa Builds quick lands like trainer Flyingweight lOlba 184 1 l3lbs 192 Ohio OHIO SUPERSTAR PRODUCTS INC 11376 RIOGEWAY ROADKENSINGTON OHIO 44427 r 216-223-1950 great idea cant resist quoting Mr Stahls comments opening paragraph Overemphasis strictly flying designs con tests throughout country recent years has brought about unwarranted condition ne glect building flying Scale semiscale models Much favoritism must tributed desire maximum performance since little need said relative appearance neatly built Scale ship usual contest design SAM Italia Dr Ferdinando Gale Baveno aly recently sent interesting handbook about Eastern bloc engines written Cesare de Robertis Well illustrated unusual model power plants text Italian available Gale Via Marconi 10 28042 Baveno NO Italy interesting material de signs emerging SAM Italia including several magnificent construction drawings beautiful Italian Gliders pre-WW II era available B2 Streamlines PO Box 976 Olalla WA 98359 RC Pylon/Hager Continued page 64 no mediocre planes event fact well done dont know pilots selected would show two three brought along would still out trying decide Id vote collection absolutely beautiful takeoff area too narrow support four planes up heats threeplane blasts Plans have made things works widen takeoff area fourplane heats can accommodated next spring top 10 finishers Saturday 1 Randy Rich 11480 2 Richard Oliver 11701 3 Red Cranfield 12189 4 Phil Bussell 11742 5 Jim Young 11859 6 Bill Hager 11539 7 Hubert Wills 11905 8 Norm Johnson 11473 9 Dub Jets 11487 10 Sam Womack 11656 Just keep everyones attention two midairs Saturday both occurring just out turn number three Poor Bob Greer par ticipant little high-speed tangos Dave Layman Bill Hager Jerry Small tried trade little paint flight wound up getting planes dirty easier transport under seat Sundays action just hot heavy make sure moves down pat Bob Greer provided present what violent midair collision since vention prop happened about 20 ft di rectly behind above head stood cage turn number pilot lane made clock locked ac tion happened felt bad pilots crash itself right out movies another midair just out turn number three tame comparison Bob Greer/Hubert Wills fiasco earlier com pletely forgot get names pilots volved Yours Truly Bill Hager Jerry SmallBH Top five finishers Sunday 1 Dub Jett 11685 2 Red Cranfield l193 Phil Bussell 12059 4 Bill Hager 11614 5 Montie Montcrief 11620 6 Clay Gary 11509 7 Dave Layman 11381 8 Norm Johnson 11415 9 Randy Ritch 11529 10 Sam Wo mack 12772 Fast time meet 11090 turned Jerry Small lot really good close tight racing action both days can per sonally vouch quality food available heard nothing praise con dition fieldits size its location think two quotes heard often Yall have best racing facilities around grass field absolutely fantastic shape nice words made feel kinda proud field proud have small part core club members come out work event got meet some super-nice guys see some beautiful planes doin some really competitive racing besides Bob Greer Ill long time talking about Sun day midair yours Take guys put first-class race the field great shape See next month Caudimordax/Taib Continued page 71 wing lift being generated farther out root Very high aspect ratio wings demand extra strength conse quently added weight spars root particular application will demand aspect ratio provides best combi nation weight efficiency Cau dimordax aspect ratio 61 cho sen allowed convenient wing span 48 inches Styrofoam comes 2-ftwide sheetsjust right wing panel mean chord eight inches al lows 10-in root 6-in tip 60% tip/root percentage Such wing core too difficult cut trailing edge swept forward three inches lead ing edge swept back inch producing net sweep quarter-chord zero Experiments straight leading edge produced airplanes unpleasant snap rolling tendencies swept leading edge also allows easier placement spars greater lead-out sweep Eliminating high-speed stall Turning airplane too tightly causes wing stall wing forced produce lift capable producing produce lift angle attack must creased Beyond certain angle attack air flow along top wing separates wings surface becomes turbu lent causing sudden increase drag Most Combat fliers adjust controls limit turn radius order avoid stal ling Another approach use thicker blunter airfoil stalls higher Us thin does drawback ap proach course thicker airfoil has greater parasitic drag top speed reduced accordingly Caudimordax root section thick 15% tip thicker 25% relatively thicker tip airfoil ensures root will stall first turn thus reduc ing airplanes tendency drop wing tip tendency causes lateral instabil ity common high aspect ratio Combat wings Longitudinal stability An airplane does tight fast turns absolutely no use cant make go want go common problem Combat wings lack longitudinal stability turn once started will tighten up its own ac cord makes airplane unpointable therefore useless Combat air plane should also able fly straight unattended An unstable airplane will tend tighten wander out turn pilot glances away inslant common misconception sta 172 Model Aviation SPORTOBATIC 2 84 For1204cycleand 902-cycle rST 200025003000-0 PS 18 NEWOS BGX 13500 bilator elevator make airplane move up down true designer could reduce stabilator area airplane thats overly sensitive unstable Actually opposite true stabilator provides stability opposing downward pitching moment produced wing larger stabilizer larger airplanes stability margin since stabilizer doesnt have work hard Similarly longer tail moment increases stability providing longer moment arm stabilizer act Spitfire airplane too small horizontal stabilizer earlier marks had very small acceptable range CG center-of-gravity ad ditional equipment added aft ac ceptable range aircrafts stability de creased fact several structural failures traced directly aircraft tight ened turns due instability Later war longer range fight ers needed long-range bomber es corts CU became issue again way extending Spitfires range especially bigger Griffon engines used later marks situating addi tional tanks behind pilot Eventually larger horizontal vertical stabilizers incorporated allow rear ward center-of-gravity addition larger tail surfaces helped control 2000-plus horsepower output big Griffon engines 12 x 3-in stabilator shown plans Caudimordax longitudinally sta ble will fly large loops want tightening up set up will turn tightly needed point stalling Earlier versions 9 x 3-in tail predictable Construction center rib tip ribs sta bilator lead-out guide bellcrank plate con trol horn engine mount assembly best cut scroll saw band saw en sure accuracy good fit Final shaping can accomplished belt disc sander sure set up tools cut sand perfect 900 angle prefer band saw scroll saw Most scroll saws dont seem have power cut through maple vibration tends obscure guide marks Band saws comparison powerful very smooth can used resawing balsa pine Have ever worked -in pine Slow fuselages cutting alu minum sheet sawing exhaust lugs off engines really nice l0-in-throat three-wheel band saw can obtained Sears little cost Dremel scroll saw Wait until theyre sale can get Christmas Life terrible before got engine mount assembly first glued together very thick CyA cyanoacrylate glue like Special-T What would Combat fliers super glue Make sure grain both balsa spacer 1/64 ply side plates vertical balsa spacer i/ ply plates may look insubstantial two dowels through maple center rib Ive yet have assemblies fail Trial fit engine mark drill holes engine mount assembly must fitted individually its intended center block marking making diagonal cuts maple Remember allow 1/i6 ply front spar Loose-fitting engine mount/center rib combinations can cor rected adding 1/64 ply spacers needed during final assembly aluminum arrow-shaft tail boom can cut length band saw size use 21/64 0D has 019 walls marked 2117 ought avail able good sporting goods store shafts use cutoffs arrows shortened cost quarter Other sizes well graph ite shafts hard come southern Indiana will work just well Use drill press jig some sort drilling hole back cen ter rib Crooked tails get laughed Drill bits available 44-in increments finding right size shouldnt problem Cut notch rear boom us ing band saw Drill two three holes front inch epoxy anchor before gluing boom block together Shallow notches made band saw will work lieu holes Stuff some tissue paper front end boom pre vent epoxy flowing boom Use slow-curing epoxy Make sure notch back end horizontal Cutting foam cores Most Combat con struction articles will tell look else foam cutting instructions method cutting foam first developed Doc Passen easiest method Ive tried yet cutting bow assembled using 1 x 2-in furring strip cutting wire 015 braided control line power source must able supply 12-13 volts 3-4 amps Variac will work does come cheap use car battery Phil Cartier uses light dimmer switch series 200-watt light bulb Write him Core House 760 Waltonville Road Hummelstown PA 17036 details Root tip templates made out -in-thick Formica edges must sanded smooth possible Candle wax rubbed edges also helps straight cuts Note centerline templates 7/ bottom compen sate fact foam rarely exactly two inches thick also 1/16 lost foam cut Put guide marks templates shown both sides well top guiding edge template patterns edge plans make convenient Xeroxing Paste Xeroxed patterns onto Formica cutting surface prepared driving nails through flat piece plywood par ticle board nails serve hold foam down flat during cutting process should penetrate about inch jig should made cutting blanks Two vertical templates needed edge table 27 apart enough space behind accommodate 8-ft -long foam sheets youre really mass production make jigs two feet high cut dozen blanks once Hold layers foam together bam boo shish kebab skewers skewers also useful holding stacks cut wings beds together storage templates held place using double-pointed pins made %-in alumi num brass welding rod Nails December 1990 173 Fly McDaniel Power New Solid State On-Board Glow-Plug Drivers Now can drive 1 2 glow plugs efficiently automatically new McDaniel On-Board Glow-Plug Drivers engine 2 4 stroke glow has 1 2 cylinders Model 471 472 On-Board Glow-Plug Driver will ease jobs starting maintaining idle during taxiing power down flight maneuvers FEATURES INCLUDE Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Connector Plug Battery Pack Remote Glow Plug Indicator Panels Available Separately Battery Pack AC Charger NOT Included Available Separately See Local Hobby Dealer Cantact McDaniel R/C IncVisa MC accepted 1654 Crofton Blvd Suite 4 Crofton MD 21114 e 3017216303 3017216306 NO OCR TEXT r 1 HALFEANLOCK 24 INCHES PATENT PENDING AT LAST positive connector for I HALF glow heads Fits COX glow heads except 020 Two types ring terminals HEAD LOCK/HEAD LITE II adapter ST#050 RING TERM-$595 ST#051 ADAPTER-$695 F IEY AVAILABLE CIDER DIRLT ADD $100 $200 UPSIDE US 12/89 MODEL PRODUCTS CORPORATION POST OFFICE BOX 100 ALLAMUCHY NJ 07820 FAX 201 850 8860 PHONE201 850 1508 IIIWWII AIRCRAFT SCALE DRAWINGS & SPECIFICATION SHEETS Antiques Military CiviIiar Helicopters Saltptanes 2700 ptvs0000 3-view drawirrpIOser 1200 cele FOTO~ K04CU-FANScrIe 3For Csrsisg RANGER FIBERGLASS RANGER FIBERGLASS CO lss bee, Box 879 spesielizirrg ssstorr design nd nrslding Campton NH tire aerospace industry since 1959 03223 S29 Magnum 28 FSR Royal 28 seems well made 25 FSRs far cry earlier Taiwanese engines Its light weight partially due its AAC piston liner As Brat originally intended RC sport flying its induction timing quite con servative Combat use necessary retime induction port replace RC carburetor large-diameter intake stack also known really venturi also helps trim off excess weight head fins dont contribute very much cooling get way changing glow plugs fins can ground off before disassembling engine Remove glow plug plug hole pieces paper toweling Also plug up air intake ex haust Grind off fins using disc belt sander leaving last 3/ intact Wash off filings detergent wa ter before removing paper towel plugs Disassemble engine cylinder liner fits very tightly case must re moved carefully Dont remove bearings Stuff case paper toweling before grinding off muffler lugs Make sure stuff some toweling down exhaust port disc belt sander good way start file can used inaccessible plac es stone Dremel tool also works will clog needs constant dressing Wash filings off detergent water before pulling out paper toweling care filings will enter engine r OFFICIAL AMA SAFETY CODEJanuary 11991 Model Flying Must Accordance Code Order AMA Liability Protection Apply GENERALflown indoors3 will perform initial turn after takeoff away 1 will fly model aircraft competition 7 will operate models metal-bladed pro- tnt spectator areas will there- U after fly over pit speceae U p spectators until has pellers gaseous boosts gases u p oven o rworthy having previ- other sir normal atmospheric pressure en- yond control ous y successfu y flight testedter internal combustion engines nor will I4 will operate model g ad operate models extremely hazardous fuelsfrequencies currently allowed Federal 2 will fly model higher approxi-such containing tetranitromethane orCommunications Commission Only properly Iimately 400 feet within 3 miles airport with-hydrazinecensed Amateurs authorized operate equip- Out notifying airport operator will give right of-way avoid flying proximity full-8 will operate models pyrotechnics anyment Amateur Bsnd frequencies Further scale aircraft necessary observerdevice explodes burns propels projec-any transmitters use sanctioned eveni shall utilized supervise flying avoid hay-tile kind including limited rock-must have certified R/CMA-AMA gold sticker af ing models fly proximity full-scale aircrafteta explosive bombs dropped modelsfixed indicating manufactured modi- U 3 established will abide safety smoke bombs explosive gases such fled operation 20kHz frequency separaeg site use will willfullyhydrogen-filled balloons ground mounted de-lion except 27MHz 53MHzU d de models careless reck-vices launching projectileThe exceptions permitted rockets flown accordance withFREE FLIGHT less and/or dangerous mannerthe Safety Code National Association 4 mode weighs over 20 pounds will onlyRocketry permanently attached per1 will launch mode c aft un ess Ify t n acco dance paragraph 5 sec-JATO use also items authorized Airleast 100 feet downwind spectato auto tion AMA Safety CodeShow Team use defined AST Advisory Coin-mobile parking 5 air shows model flying demonstrations amittee document available AMA HO Note2 will fly model unless launch area single straight line must established sideA model aircraft defined aircraft orclear persons except mechanic offi flying other side spec-without engine able carry human beingcials I tators Only persons essential flight 9 will fly model using turbojet power ax operations permitted flying sideat centrifugal flowi unless have obtained a3 will employ use adequate dev ce n line others must spectatorspecial waiver such specific flights theflight extinguish fuses mode afte de F g spectator side line isAMA President Executive Director willhas completed its function Ip b e beyond control theabide restrictions imposed such flights pilots exceptions may permitby Note does apply ducted fanCONTROL LINE Ited single straight line requirement undermodels using piston engines electric motors special circumstances involving consideration of11 will subject comp m site conditions model size weight speedRADIO CONTROLcluding safety thong applicable inand power must jointly approved AMAspection pull test prior flying President Executive Director maxi-1 twill have completed successful radio equipmum permissible takeoff weight models 55ment ground range check before first flight of21 will assure flying area safely clear Ilbsa new repaired modelof utility wires poles 6 will fly model unless identified with2 will fly model aircraft presence3 will assure fly g a name address AMA number inof spectators until become qualified flier un-of non-essential participants spectators model Note does apply modelsless assisted experienced helperbefore permitting engine started make sure wash out case thoroughly An old toothbrush helps Thoroughly dry oil bearings As stated earlier intake port crankshaft must opened up increase angle remains open Before retiming crank scratch tim ing diagram shown plans onto piece transparent rigid plastic using scribe Thin Plexiglas should work well Insert crankshaft case Slipping drive washer prop nut will help hold shaft proper position Holding engine nose down lay tim ing diagram onto rear engine Line up cross hairs bottom mounting lugs mold flashing centerline engine Referring figure lA rotate shaft un til middle crankpin lines up opening line holding crankshaft position insert hard metal scribe through intake stack make mark crank Use bottom edge frft looking rear side intake port crankcase guide youve set up correctly port should totally closed off shaft doing likewise closing side take port referring figure lB time make mark right side port intake stack can made /2-inOD aluminum nylon brass tubing wall thickness should /32 /16 Wrap Teflon tape around tube ensure good seal intend use remote needle drill tap 6-32 Du-Bro pressure fitting 1/ above stack slips case remote needle made 05 RC needle valve assembly mounted engine bearers using nylon control horn 2-56 sheet metal screws Wash engine parts using hot water dishwashing detergent Dry off parts us ing paper toweling Oil parts WD 40 Break-Free reassemble engine Flying Caudimordax flies best CU line spars using about four five pennies tip weight approximately 13-16 grams Attach streamer test flying Line rake usually set maximum two rearmost holes lead-out guide Brats seem like 7 x 6 Taipan props use 25% Red Max fuel half castor half synthetic oil back-flipping chickenstick technique described Charlie Johnson Combat column seems work best quick starts flying airplane first time check warps Fly level upright note whether either wing appears flying high outboard wing higher inboard very carefully flip airplane onto its back outboard wing flies low have warp still flies high add tip weight outboard wing flies low upright high inverted have warp other way Dont tight turns warped air plane Take home use heat gun shrink covering needed eliminate warp flying against faster opponent use Caudimordaxs superior turning radius advantage Follow opponent through turns advantage level speed negated have actually able fly up others tail pipes occasion Always lookout leading edge kill opponent makes pass streamer often sets him up overshoot thats leading edge kill can ac complished name Caudimordax Doc Passen calls Quasimodo comes Tolkiens book Farmer Giles Ham Naming Combat de signs after weapons named Tolkiens bet ter known book Lord Rings old tra dition Combat circles Orcrist Andu ril English FAI designs instance Glamdring Guthwine Aeglos still up grabs Sting would make good name Anglachel though wouldnt appropriate airplane hope will fly Caudimordax however uniquely appro priate Combat airplane sword also known vulgar tongue Tailbiter habit leaping out its sheath whenever dragon near tra dition time knights kill dra gons cut off tails serve delicacy court sword given Farmer Giles put good use Further development As Combat designs Caudimordax anything static Combat designs evolve faster due high rate destruction Dont afraid try out different airfoils different tail mo ments different construction techniques Per ryman tips Ford Taurus styling Steve Hills Arrowplane wont will can stick Fox 36 nose please use least 34-in-thick wood center block 3/4 x 3A-in maple engine mounts never build Caudimordax article others ought give few ideas improve other design design own Nearly construction techniques used airplane filched others Id like thank too ideas used design Terry Doc Passen foam cutting engine retiming techniques tail hinge bellcrank mount pushrod Phil Cartier arrow-shaft tail boom techniques bladder compartment idea using smaller engines first place Rich ard Wilkens front spar foam cutting bow CL Scale/Boss Continued page 72 Ontario Canada CL Scale judged June 30th flown July 1st Mike reports disappointing CL Scale entry five Two Canadians other three US Its surprising US modelers north central area country werent hand com petition contest site about three hours Buffalo NY about two hours Detroit MI well within days drive several north central statesContinued page 178 December 1990 177 DOE Z2Li2 TNROFILES AND SUPPLIES FOR ELECTRIC FLIGHT SM5 1 6 cells tu u amps SM4 7 23 cells 50 amps Sc6 24 34 cells 60 amps -all throttles linear proportional forward only#15 WiRE 350 STRAND 020 25 size #12 WIRE 665 STRAND 25 100 siz Toas ac4da6ge s 44ff Call write JOMAR 513-474-0985 2028 Knightsbridge Dr. Cincinnati OH 45244
Edition: Model Aviation - 1990/12
Page Numbers: 68, 69, 70, 71, 172, 173, 174, 176, 177
Caudimordax Fast Combat smaller engines works Three ounces fuel can last up five minutes shoulder stays piece slower tight-turning ship gives edge over opponentand engine costs lot less Hlskandar Taib AMERICAN COMBAT design philosophy has traditionally favored speed over turning ability Note large sums money spent Hoffelts custom Foxes bolted onto 300- 400-sq-in airplanes weighing 21 oz What en gines share besides enormous power output weight Most weigh about 9/2 oz Caudimordax design takes other approach high rate turn small turning radius given top priority qualities achieved using light engine high aspect ratio wing compromise speed Caudimordax Brat 28 flies 10 15 mph slower level flight typical Fast Combat job makes up turns though much tighter actually slow down ship much less would heavier model Flying Fast Combat smaller engines has other advantages Three ounces fuel Left left unmodified Brat 28 stIll sporting its RC carburetor author has several give away right modified Brat 28 Note missing metal around exhaust port thinned head fins homemade venturi 7 x 6 Talpal prop Right Close-up view remote needle valve assembly unit OS 10 FSR RC used Note short length tubing slipped over end needle valve prevent leakage plastic clip fuel line available author 68 Model Aviation Author/builder Iskandar Taib holding Caudimordax thoroughly designed Combat plane gives up some top speed typically 10-15 mph makes up barely slowing corners Light weight along special modifications engine make possible Left Mark made crankshaft intake ports closing side Right Mark made opening side Note amount metal has removed Brats have very conservative timing befits its sport RC roots Left Front end tail boom Note shallow cuts made aluminum epoxy grab Small holes may drilled instead Right Engine mount assembly center rib Mount marked sawing using front center rib pattern ft Components horizontal stabilizer Start epoxying arrow shaft stab anchor Glue hinge assembly stab anchor cover horizontal stab -In medium balsa glue stab anchor Right completed tail assembly Notice hinge built String wrapped figure-eight pattern around two 3As dowels December 1990 69 F 4 4 \ - will last five minutes airplane doesnt dislocate shoulder its fast cant keep up slower tight-turning airplane can also hard opponent line up have gotten several kills other guy overshot attack Perhaps important engines cost far less bigger counterparts Caudimordax can also used Out law FAJ contests sprouting up over Midwest Rules typically specify Fast Slow rules 15 engines 52-ft lines no restrictions engine tank setups nitro content fuel Most Schnuerle-ported double ball bear ing 15s weigh about six ounces 34 oz less Brat 28 modifications needed use slightly smaller typically l/ engine bearer spacing mount engine slightly further ward Caudimordax design goes back sev eral years evolving slowly its present form admittedly incorporating features currently vogue External con trols instance now being used top fliers including Russians save much building time allowing use solid wing panels Another great time-saver simple cutout blad der tank replaces common rocket tube arrow-shaft tail boom al though requires little extra building time allows easier rebuilding saves little weight agility Caudimordax attribut able its high aspect ratio wing thick airfoil high aspect ratio reduces tip vortices cause induced drag thick airfoil delays onset high-speed stall thick airfoil also lends lateral sta FAST COMBAT DESIGN ESR 23-32 ENGINES bility design helps control snap rolling associated high aspect ratio designs Induced drag Just what induced drag its reduction important Combat design Drag generally divided two types often confused Parasitic drag caused friction air surface airplane therefore proportional surface area wing Also included category drag lines drag caused protuberances airplane such pushrod engine cylinder Streamlining serves reduce parasitic drag Induced drag other hand re lated lift produced wing wing producing lift pressure air bottom surface wing greater pressure top pressure differences cause air above wings move outward toward wing tips air below wings move toward root tips nothing pre vent air below wings curling around tips pushing down top surface wing reducing actual amount lift produced airflow around wing tip also pro duces turbulent vortices often visible va por trails emanating wing tips jet fighters during high-G maneuvers energy needed drive vortices ulti mately Linked drag drag sociated vortices de scribed induced drag greater lift 70 Model Aviation Pushrod braces made outer Sullivan Ny-Rod Filament tape wraps tail boom bed nails particular piece made out straight section chip-core board Full-Size Plans Available. Page 200 nI 1~ ** TJ / produced wing larger vor tices Several strategies exist reduction tip vortices Tip fences instance will impede air flowing around wing tips Low aspect ratio wings would benefit tip fences Ed Brzys listen ing Theyve seen full-scale air planes low aspect ratio wings such pretty Racing biplane Sorceress Hoer ner anti-vortex tips variation tip fence shaped force airflow tips counter direction tip vor tex However work air plane experiences positive Gs Flip air plane its back anti-vortex tips ac tually add problem Forward sweep wing causes air flow move toward root can spill cause vortex forward swept wings have extremely rigid withstand aeroelastic twisting forces increase wing twists technically known aeroelastic divergence Another way improve efficiency lift/drag ratio wing use smaller wing tip Wind tunnel experiments have shown Schuemann planform shouldnt called George Perryman planform currently vogue glider pi lots has least amount induced drag given amount lift elliptical planform eg Spitfire almost good wing no taper 60% 65% efficient elliptical wing same pect ratio wing tip chord 60% 65% root chord 90% 95% efficient turn tapered wing produces lot less induced drag nontapered High aspect ratio wings have smaller amounts tip spillage low aspect ratio wings less wing tip length per unit area Glider wings have high aspect ratios very purpose High aspect ratio wings have own problems however main being added bending stresses put Continued page 172 Left Cutting top surface wing core Core held tightly board embedded nalis Note bow held Right Cutting spar slot Slot cut single pass down back up Author gives complete directions foam wing cutting something rarely done December 1990 71 / 7- design drawing Nur Iskandar Taib modela fill need hotdog show-off sport plane Knife edge take-offs flat apins snaps anything can Wing foam Fuselage Tail lite ply balsa Builds quick lands like trainer Flyingweight lOlba 184 1 l3lbs 192 Ohio OHIO SUPERSTAR PRODUCTS INC 11376 RIOGEWAY ROADKENSINGTON OHIO 44427 r 216-223-1950 great idea cant resist quoting Mr Stahls comments opening paragraph Overemphasis strictly flying designs con tests throughout country recent years has brought about unwarranted condition ne glect building flying Scale semiscale models Much favoritism must tributed desire maximum performance since little need said relative appearance neatly built Scale ship usual contest design SAM Italia Dr Ferdinando Gale Baveno aly recently sent interesting handbook about Eastern bloc engines written Cesare de Robertis Well illustrated unusual model power plants text Italian available Gale Via Marconi 10 28042 Baveno NO Italy interesting material de signs emerging SAM Italia including several magnificent construction drawings beautiful Italian Gliders pre-WW II era available B2 Streamlines PO Box 976 Olalla WA 98359 RC Pylon/Hager Continued page 64 no mediocre planes event fact well done dont know pilots selected would show two three brought along would still out trying decide Id vote collection absolutely beautiful takeoff area too narrow support four planes up heats threeplane blasts Plans have made things works widen takeoff area fourplane heats can accommodated next spring top 10 finishers Saturday 1 Randy Rich 11480 2 Richard Oliver 11701 3 Red Cranfield 12189 4 Phil Bussell 11742 5 Jim Young 11859 6 Bill Hager 11539 7 Hubert Wills 11905 8 Norm Johnson 11473 9 Dub Jets 11487 10 Sam Womack 11656 Just keep everyones attention two midairs Saturday both occurring just out turn number three Poor Bob Greer par ticipant little high-speed tangos Dave Layman Bill Hager Jerry Small tried trade little paint flight wound up getting planes dirty easier transport under seat Sundays action just hot heavy make sure moves down pat Bob Greer provided present what violent midair collision since vention prop happened about 20 ft di rectly behind above head stood cage turn number pilot lane made clock locked ac tion happened felt bad pilots crash itself right out movies another midair just out turn number three tame comparison Bob Greer/Hubert Wills fiasco earlier com pletely forgot get names pilots volved Yours Truly Bill Hager Jerry SmallBH Top five finishers Sunday 1 Dub Jett 11685 2 Red Cranfield l193 Phil Bussell 12059 4 Bill Hager 11614 5 Montie Montcrief 11620 6 Clay Gary 11509 7 Dave Layman 11381 8 Norm Johnson 11415 9 Randy Ritch 11529 10 Sam Wo mack 12772 Fast time meet 11090 turned Jerry Small lot really good close tight racing action both days can per sonally vouch quality food available heard nothing praise con dition fieldits size its location think two quotes heard often Yall have best racing facilities around grass field absolutely fantastic shape nice words made feel kinda proud field proud have small part core club members come out work event got meet some super-nice guys see some beautiful planes doin some really competitive racing besides Bob Greer Ill long time talking about Sun day midair yours Take guys put first-class race the field great shape See next month Caudimordax/Taib Continued page 71 wing lift being generated farther out root Very high aspect ratio wings demand extra strength conse quently added weight spars root particular application will demand aspect ratio provides best combi nation weight efficiency Cau dimordax aspect ratio 61 cho sen allowed convenient wing span 48 inches Styrofoam comes 2-ftwide sheetsjust right wing panel mean chord eight inches al lows 10-in root 6-in tip 60% tip/root percentage Such wing core too difficult cut trailing edge swept forward three inches lead ing edge swept back inch producing net sweep quarter-chord zero Experiments straight leading edge produced airplanes unpleasant snap rolling tendencies swept leading edge also allows easier placement spars greater lead-out sweep Eliminating high-speed stall Turning airplane too tightly causes wing stall wing forced produce lift capable producing produce lift angle attack must creased Beyond certain angle attack air flow along top wing separates wings surface becomes turbu lent causing sudden increase drag Most Combat fliers adjust controls limit turn radius order avoid stal ling Another approach use thicker blunter airfoil stalls higher Us thin does drawback ap proach course thicker airfoil has greater parasitic drag top speed reduced accordingly Caudimordax root section thick 15% tip thicker 25% relatively thicker tip airfoil ensures root will stall first turn thus reduc ing airplanes tendency drop wing tip tendency causes lateral instabil ity common high aspect ratio Combat wings Longitudinal stability An airplane does tight fast turns absolutely no use cant make go want go common problem Combat wings lack longitudinal stability turn once started will tighten up its own ac cord makes airplane unpointable therefore useless Combat air plane should also able fly straight unattended An unstable airplane will tend tighten wander out turn pilot glances away inslant common misconception sta 172 Model Aviation SPORTOBATIC 2 84 For1204cycleand 902-cycle rST 200025003000-0 PS 18 NEWOS BGX 13500 bilator elevator make airplane move up down true designer could reduce stabilator area airplane thats overly sensitive unstable Actually opposite true stabilator provides stability opposing downward pitching moment produced wing larger stabilizer larger airplanes stability margin since stabilizer doesnt have work hard Similarly longer tail moment increases stability providing longer moment arm stabilizer act Spitfire airplane too small horizontal stabilizer earlier marks had very small acceptable range CG center-of-gravity ad ditional equipment added aft ac ceptable range aircrafts stability de creased fact several structural failures traced directly aircraft tight ened turns due instability Later war longer range fight ers needed long-range bomber es corts CU became issue again way extending Spitfires range especially bigger Griffon engines used later marks situating addi tional tanks behind pilot Eventually larger horizontal vertical stabilizers incorporated allow rear ward center-of-gravity addition larger tail surfaces helped control 2000-plus horsepower output big Griffon engines 12 x 3-in stabilator shown plans Caudimordax longitudinally sta ble will fly large loops want tightening up set up will turn tightly needed point stalling Earlier versions 9 x 3-in tail predictable Construction center rib tip ribs sta bilator lead-out guide bellcrank plate con trol horn engine mount assembly best cut scroll saw band saw en sure accuracy good fit Final shaping can accomplished belt disc sander sure set up tools cut sand perfect 900 angle prefer band saw scroll saw Most scroll saws dont seem have power cut through maple vibration tends obscure guide marks Band saws comparison powerful very smooth can used resawing balsa pine Have ever worked -in pine Slow fuselages cutting alu minum sheet sawing exhaust lugs off engines really nice l0-in-throat three-wheel band saw can obtained Sears little cost Dremel scroll saw Wait until theyre sale can get Christmas Life terrible before got engine mount assembly first glued together very thick CyA cyanoacrylate glue like Special-T What would Combat fliers super glue Make sure grain both balsa spacer 1/64 ply side plates vertical balsa spacer i/ ply plates may look insubstantial two dowels through maple center rib Ive yet have assemblies fail Trial fit engine mark drill holes engine mount assembly must fitted individually its intended center block marking making diagonal cuts maple Remember allow 1/i6 ply front spar Loose-fitting engine mount/center rib combinations can cor rected adding 1/64 ply spacers needed during final assembly aluminum arrow-shaft tail boom can cut length band saw size use 21/64 0D has 019 walls marked 2117 ought avail able good sporting goods store shafts use cutoffs arrows shortened cost quarter Other sizes well graph ite shafts hard come southern Indiana will work just well Use drill press jig some sort drilling hole back cen ter rib Crooked tails get laughed Drill bits available 44-in increments finding right size shouldnt problem Cut notch rear boom us ing band saw Drill two three holes front inch epoxy anchor before gluing boom block together Shallow notches made band saw will work lieu holes Stuff some tissue paper front end boom pre vent epoxy flowing boom Use slow-curing epoxy Make sure notch back end horizontal Cutting foam cores Most Combat con struction articles will tell look else foam cutting instructions method cutting foam first developed Doc Passen easiest method Ive tried yet cutting bow assembled using 1 x 2-in furring strip cutting wire 015 braided control line power source must able supply 12-13 volts 3-4 amps Variac will work does come cheap use car battery Phil Cartier uses light dimmer switch series 200-watt light bulb Write him Core House 760 Waltonville Road Hummelstown PA 17036 details Root tip templates made out -in-thick Formica edges must sanded smooth possible Candle wax rubbed edges also helps straight cuts Note centerline templates 7/ bottom compen sate fact foam rarely exactly two inches thick also 1/16 lost foam cut Put guide marks templates shown both sides well top guiding edge template patterns edge plans make convenient Xeroxing Paste Xeroxed patterns onto Formica cutting surface prepared driving nails through flat piece plywood par ticle board nails serve hold foam down flat during cutting process should penetrate about inch jig should made cutting blanks Two vertical templates needed edge table 27 apart enough space behind accommodate 8-ft -long foam sheets youre really mass production make jigs two feet high cut dozen blanks once Hold layers foam together bam boo shish kebab skewers skewers also useful holding stacks cut wings beds together storage templates held place using double-pointed pins made %-in alumi num brass welding rod Nails December 1990 173 Fly McDaniel Power New Solid State On-Board Glow-Plug Drivers Now can drive 1 2 glow plugs efficiently automatically new McDaniel On-Board Glow-Plug Drivers engine 2 4 stroke glow has 1 2 cylinders Model 471 472 On-Board Glow-Plug Driver will ease jobs starting maintaining idle during taxiing power down flight maneuvers FEATURES INCLUDE Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Connector Plug Battery Pack Remote Glow Plug Indicator Panels Available Separately Battery Pack AC Charger NOT Included Available Separately See Local Hobby Dealer Cantact McDaniel R/C IncVisa MC accepted 1654 Crofton Blvd Suite 4 Crofton MD 21114 e 3017216303 3017216306 NO OCR TEXT r 1 HALFEANLOCK 24 INCHES PATENT PENDING AT LAST positive connector for I HALF glow heads Fits COX glow heads except 020 Two types ring terminals HEAD LOCK/HEAD LITE II adapter ST#050 RING TERM-$595 ST#051 ADAPTER-$695 F IEY AVAILABLE CIDER DIRLT ADD $100 $200 UPSIDE US 12/89 MODEL PRODUCTS CORPORATION POST OFFICE BOX 100 ALLAMUCHY NJ 07820 FAX 201 850 8860 PHONE201 850 1508 IIIWWII AIRCRAFT SCALE DRAWINGS & SPECIFICATION SHEETS Antiques Military CiviIiar Helicopters Saltptanes 2700 ptvs0000 3-view drawirrpIOser 1200 cele FOTO~ K04CU-FANScrIe 3For Csrsisg RANGER FIBERGLASS RANGER FIBERGLASS CO lss bee, Box 879 spesielizirrg ssstorr design nd nrslding Campton NH tire aerospace industry since 1959 03223 S29 Magnum 28 FSR Royal 28 seems well made 25 FSRs far cry earlier Taiwanese engines Its light weight partially due its AAC piston liner As Brat originally intended RC sport flying its induction timing quite con servative Combat use necessary retime induction port replace RC carburetor large-diameter intake stack also known really venturi also helps trim off excess weight head fins dont contribute very much cooling get way changing glow plugs fins can ground off before disassembling engine Remove glow plug plug hole pieces paper toweling Also plug up air intake ex haust Grind off fins using disc belt sander leaving last 3/ intact Wash off filings detergent wa ter before removing paper towel plugs Disassemble engine cylinder liner fits very tightly case must re moved carefully Dont remove bearings Stuff case paper toweling before grinding off muffler lugs Make sure stuff some toweling down exhaust port disc belt sander good way start file can used inaccessible plac es stone Dremel tool also works will clog needs constant dressing Wash filings off detergent water before pulling out paper toweling care filings will enter engine r OFFICIAL AMA SAFETY CODEJanuary 11991 Model Flying Must Accordance Code Order AMA Liability Protection Apply GENERALflown indoors3 will perform initial turn after takeoff away 1 will fly model aircraft competition 7 will operate models metal-bladed pro- tnt spectator areas will there- U after fly over pit speceae U p spectators until has pellers gaseous boosts gases u p oven o rworthy having previ- other sir normal atmospheric pressure en- yond control ous y successfu y flight testedter internal combustion engines nor will I4 will operate model g ad operate models extremely hazardous fuelsfrequencies currently allowed Federal 2 will fly model higher approxi-such containing tetranitromethane orCommunications Commission Only properly Iimately 400 feet within 3 miles airport with-hydrazinecensed Amateurs authorized operate equip- Out notifying airport operator will give right of-way avoid flying proximity full-8 will operate models pyrotechnics anyment Amateur Bsnd frequencies Further scale aircraft necessary observerdevice explodes burns propels projec-any transmitters use sanctioned eveni shall utilized supervise flying avoid hay-tile kind including limited rock-must have certified R/CMA-AMA gold sticker af ing models fly proximity full-scale aircrafteta explosive bombs dropped modelsfixed indicating manufactured modi- U 3 established will abide safety smoke bombs explosive gases such fled operation 20kHz frequency separaeg site use will willfullyhydrogen-filled balloons ground mounted de-lion except 27MHz 53MHzU d de models careless reck-vices launching projectileThe exceptions permitted rockets flown accordance withFREE FLIGHT less and/or dangerous mannerthe Safety Code National Association 4 mode weighs over 20 pounds will onlyRocketry permanently attached per1 will launch mode c aft un ess Ify t n acco dance paragraph 5 sec-JATO use also items authorized Airleast 100 feet downwind spectato auto tion AMA Safety CodeShow Team use defined AST Advisory Coin-mobile parking 5 air shows model flying demonstrations amittee document available AMA HO Note2 will fly model unless launch area single straight line must established sideA model aircraft defined aircraft orclear persons except mechanic offi flying other side spec-without engine able carry human beingcials I tators Only persons essential flight 9 will fly model using turbojet power ax operations permitted flying sideat centrifugal flowi unless have obtained a3 will employ use adequate dev ce n line others must spectatorspecial waiver such specific flights theflight extinguish fuses mode afte de F g spectator side line isAMA President Executive Director willhas completed its function Ip b e beyond control theabide restrictions imposed such flights pilots exceptions may permitby Note does apply ducted fanCONTROL LINE Ited single straight line requirement undermodels using piston engines electric motors special circumstances involving consideration of11 will subject comp m site conditions model size weight speedRADIO CONTROLcluding safety thong applicable inand power must jointly approved AMAspection pull test prior flying President Executive Director maxi-1 twill have completed successful radio equipmum permissible takeoff weight models 55ment ground range check before first flight of21 will assure flying area safely clear Ilbsa new repaired modelof utility wires poles 6 will fly model unless identified with2 will fly model aircraft presence3 will assure fly g a name address AMA number inof spectators until become qualified flier un-of non-essential participants spectators model Note does apply modelsless assisted experienced helperbefore permitting engine started make sure wash out case thoroughly An old toothbrush helps Thoroughly dry oil bearings As stated earlier intake port crankshaft must opened up increase angle remains open Before retiming crank scratch tim ing diagram shown plans onto piece transparent rigid plastic using scribe Thin Plexiglas should work well Insert crankshaft case Slipping drive washer prop nut will help hold shaft proper position Holding engine nose down lay tim ing diagram onto rear engine Line up cross hairs bottom mounting lugs mold flashing centerline engine Referring figure lA rotate shaft un til middle crankpin lines up opening line holding crankshaft position insert hard metal scribe through intake stack make mark crank Use bottom edge frft looking rear side intake port crankcase guide youve set up correctly port should totally closed off shaft doing likewise closing side take port referring figure lB time make mark right side port intake stack can made /2-inOD aluminum nylon brass tubing wall thickness should /32 /16 Wrap Teflon tape around tube ensure good seal intend use remote needle drill tap 6-32 Du-Bro pressure fitting 1/ above stack slips case remote needle made 05 RC needle valve assembly mounted engine bearers using nylon control horn 2-56 sheet metal screws Wash engine parts using hot water dishwashing detergent Dry off parts us ing paper toweling Oil parts WD 40 Break-Free reassemble engine Flying Caudimordax flies best CU line spars using about four five pennies tip weight approximately 13-16 grams Attach streamer test flying Line rake usually set maximum two rearmost holes lead-out guide Brats seem like 7 x 6 Taipan props use 25% Red Max fuel half castor half synthetic oil back-flipping chickenstick technique described Charlie Johnson Combat column seems work best quick starts flying airplane first time check warps Fly level upright note whether either wing appears flying high outboard wing higher inboard very carefully flip airplane onto its back outboard wing flies low have warp still flies high add tip weight outboard wing flies low upright high inverted have warp other way Dont tight turns warped air plane Take home use heat gun shrink covering needed eliminate warp flying against faster opponent use Caudimordaxs superior turning radius advantage Follow opponent through turns advantage level speed negated have actually able fly up others tail pipes occasion Always lookout leading edge kill opponent makes pass streamer often sets him up overshoot thats leading edge kill can ac complished name Caudimordax Doc Passen calls Quasimodo comes Tolkiens book Farmer Giles Ham Naming Combat de signs after weapons named Tolkiens bet ter known book Lord Rings old tra dition Combat circles Orcrist Andu ril English FAI designs instance Glamdring Guthwine Aeglos still up grabs Sting would make good name Anglachel though wouldnt appropriate airplane hope will fly Caudimordax however uniquely appro priate Combat airplane sword also known vulgar tongue Tailbiter habit leaping out its sheath whenever dragon near tra dition time knights kill dra gons cut off tails serve delicacy court sword given Farmer Giles put good use Further development As Combat designs Caudimordax anything static Combat designs evolve faster due high rate destruction Dont afraid try out different airfoils different tail mo ments different construction techniques Per ryman tips Ford Taurus styling Steve Hills Arrowplane wont will can stick Fox 36 nose please use least 34-in-thick wood center block 3/4 x 3A-in maple engine mounts never build Caudimordax article others ought give few ideas improve other design design own Nearly construction techniques used airplane filched others Id like thank too ideas used design Terry Doc Passen foam cutting engine retiming techniques tail hinge bellcrank mount pushrod Phil Cartier arrow-shaft tail boom techniques bladder compartment idea using smaller engines first place Rich ard Wilkens front spar foam cutting bow CL Scale/Boss Continued page 72 Ontario Canada CL Scale judged June 30th flown July 1st Mike reports disappointing CL Scale entry five Two Canadians other three US Its surprising US modelers north central area country werent hand com petition contest site about three hours Buffalo NY about two hours Detroit MI well within days drive several north central statesContinued page 178 December 1990 177 DOE Z2Li2 TNROFILES AND SUPPLIES FOR ELECTRIC FLIGHT SM5 1 6 cells tu u amps SM4 7 23 cells 50 amps Sc6 24 34 cells 60 amps -all throttles linear proportional forward only#15 WiRE 350 STRAND 020 25 size #12 WIRE 665 STRAND 25 100 siz Toas ac4da6ge s 44ff Call write JOMAR 513-474-0985 2028 Knightsbridge Dr. Cincinnati OH 45244
Edition: Model Aviation - 1990/12
Page Numbers: 68, 69, 70, 71, 172, 173, 174, 176, 177
Caudimordax Fast Combat smaller engines works Three ounces fuel can last up five minutes shoulder stays piece slower tight-turning ship gives edge over opponentand engine costs lot less Hlskandar Taib AMERICAN COMBAT design philosophy has traditionally favored speed over turning ability Note large sums money spent Hoffelts custom Foxes bolted onto 300- 400-sq-in airplanes weighing 21 oz What en gines share besides enormous power output weight Most weigh about 9/2 oz Caudimordax design takes other approach high rate turn small turning radius given top priority qualities achieved using light engine high aspect ratio wing compromise speed Caudimordax Brat 28 flies 10 15 mph slower level flight typical Fast Combat job makes up turns though much tighter actually slow down ship much less would heavier model Flying Fast Combat smaller engines has other advantages Three ounces fuel Left left unmodified Brat 28 stIll sporting its RC carburetor author has several give away right modified Brat 28 Note missing metal around exhaust port thinned head fins homemade venturi 7 x 6 Talpal prop Right Close-up view remote needle valve assembly unit OS 10 FSR RC used Note short length tubing slipped over end needle valve prevent leakage plastic clip fuel line available author 68 Model Aviation Author/builder Iskandar Taib holding Caudimordax thoroughly designed Combat plane gives up some top speed typically 10-15 mph makes up barely slowing corners Light weight along special modifications engine make possible Left Mark made crankshaft intake ports closing side Right Mark made opening side Note amount metal has removed Brats have very conservative timing befits its sport RC roots Left Front end tail boom Note shallow cuts made aluminum epoxy grab Small holes may drilled instead Right Engine mount assembly center rib Mount marked sawing using front center rib pattern ft Components horizontal stabilizer Start epoxying arrow shaft stab anchor Glue hinge assembly stab anchor cover horizontal stab -In medium balsa glue stab anchor Right completed tail assembly Notice hinge built String wrapped figure-eight pattern around two 3As dowels December 1990 69 F 4 4 \ - will last five minutes airplane doesnt dislocate shoulder its fast cant keep up slower tight-turning airplane can also hard opponent line up have gotten several kills other guy overshot attack Perhaps important engines cost far less bigger counterparts Caudimordax can also used Out law FAJ contests sprouting up over Midwest Rules typically specify Fast Slow rules 15 engines 52-ft lines no restrictions engine tank setups nitro content fuel Most Schnuerle-ported double ball bear ing 15s weigh about six ounces 34 oz less Brat 28 modifications needed use slightly smaller typically l/ engine bearer spacing mount engine slightly further ward Caudimordax design goes back sev eral years evolving slowly its present form admittedly incorporating features currently vogue External con trols instance now being used top fliers including Russians save much building time allowing use solid wing panels Another great time-saver simple cutout blad der tank replaces common rocket tube arrow-shaft tail boom al though requires little extra building time allows easier rebuilding saves little weight agility Caudimordax attribut able its high aspect ratio wing thick airfoil high aspect ratio reduces tip vortices cause induced drag thick airfoil delays onset high-speed stall thick airfoil also lends lateral sta FAST COMBAT DESIGN ESR 23-32 ENGINES bility design helps control snap rolling associated high aspect ratio designs Induced drag Just what induced drag its reduction important Combat design Drag generally divided two types often confused Parasitic drag caused friction air surface airplane therefore proportional surface area wing Also included category drag lines drag caused protuberances airplane such pushrod engine cylinder Streamlining serves reduce parasitic drag Induced drag other hand re lated lift produced wing wing producing lift pressure air bottom surface wing greater pressure top pressure differences cause air above wings move outward toward wing tips air below wings move toward root tips nothing pre vent air below wings curling around tips pushing down top surface wing reducing actual amount lift produced airflow around wing tip also pro duces turbulent vortices often visible va por trails emanating wing tips jet fighters during high-G maneuvers energy needed drive vortices ulti mately Linked drag drag sociated vortices de scribed induced drag greater lift 70 Model Aviation Pushrod braces made outer Sullivan Ny-Rod Filament tape wraps tail boom bed nails particular piece made out straight section chip-core board Full-Size Plans Available. Page 200 nI 1~ ** TJ / produced wing larger vor tices Several strategies exist reduction tip vortices Tip fences instance will impede air flowing around wing tips Low aspect ratio wings would benefit tip fences Ed Brzys listen ing Theyve seen full-scale air planes low aspect ratio wings such pretty Racing biplane Sorceress Hoer ner anti-vortex tips variation tip fence shaped force airflow tips counter direction tip vor tex However work air plane experiences positive Gs Flip air plane its back anti-vortex tips ac tually add problem Forward sweep wing causes air flow move toward root can spill cause vortex forward swept wings have extremely rigid withstand aeroelastic twisting forces increase wing twists technically known aeroelastic divergence Another way improve efficiency lift/drag ratio wing use smaller wing tip Wind tunnel experiments have shown Schuemann planform shouldnt called George Perryman planform currently vogue glider pi lots has least amount induced drag given amount lift elliptical planform eg Spitfire almost good wing no taper 60% 65% efficient elliptical wing same pect ratio wing tip chord 60% 65% root chord 90% 95% efficient turn tapered wing produces lot less induced drag nontapered High aspect ratio wings have smaller amounts tip spillage low aspect ratio wings less wing tip length per unit area Glider wings have high aspect ratios very purpose High aspect ratio wings have own problems however main being added bending stresses put Continued page 172 Left Cutting top surface wing core Core held tightly board embedded nalis Note bow held Right Cutting spar slot Slot cut single pass down back up Author gives complete directions foam wing cutting something rarely done December 1990 71 / 7- design drawing Nur Iskandar Taib modela fill need hotdog show-off sport plane Knife edge take-offs flat apins snaps anything can Wing foam Fuselage Tail lite ply balsa Builds quick lands like trainer Flyingweight lOlba 184 1 l3lbs 192 Ohio OHIO SUPERSTAR PRODUCTS INC 11376 RIOGEWAY ROADKENSINGTON OHIO 44427 r 216-223-1950 great idea cant resist quoting Mr Stahls comments opening paragraph Overemphasis strictly flying designs con tests throughout country recent years has brought about unwarranted condition ne glect building flying Scale semiscale models Much favoritism must tributed desire maximum performance since little need said relative appearance neatly built Scale ship usual contest design SAM Italia Dr Ferdinando Gale Baveno aly recently sent interesting handbook about Eastern bloc engines written Cesare de Robertis Well illustrated unusual model power plants text Italian available Gale Via Marconi 10 28042 Baveno NO Italy interesting material de signs emerging SAM Italia including several magnificent construction drawings beautiful Italian Gliders pre-WW II era available B2 Streamlines PO Box 976 Olalla WA 98359 RC Pylon/Hager Continued page 64 no mediocre planes event fact well done dont know pilots selected would show two three brought along would still out trying decide Id vote collection absolutely beautiful takeoff area too narrow support four planes up heats threeplane blasts Plans have made things works widen takeoff area fourplane heats can accommodated next spring top 10 finishers Saturday 1 Randy Rich 11480 2 Richard Oliver 11701 3 Red Cranfield 12189 4 Phil Bussell 11742 5 Jim Young 11859 6 Bill Hager 11539 7 Hubert Wills 11905 8 Norm Johnson 11473 9 Dub Jets 11487 10 Sam Womack 11656 Just keep everyones attention two midairs Saturday both occurring just out turn number three Poor Bob Greer par ticipant little high-speed tangos Dave Layman Bill Hager Jerry Small tried trade little paint flight wound up getting planes dirty easier transport under seat Sundays action just hot heavy make sure moves down pat Bob Greer provided present what violent midair collision since vention prop happened about 20 ft di rectly behind above head stood cage turn number pilot lane made clock locked ac tion happened felt bad pilots crash itself right out movies another midair just out turn number three tame comparison Bob Greer/Hubert Wills fiasco earlier com pletely forgot get names pilots volved Yours Truly Bill Hager Jerry SmallBH Top five finishers Sunday 1 Dub Jett 11685 2 Red Cranfield l193 Phil Bussell 12059 4 Bill Hager 11614 5 Montie Montcrief 11620 6 Clay Gary 11509 7 Dave Layman 11381 8 Norm Johnson 11415 9 Randy Ritch 11529 10 Sam Wo mack 12772 Fast time meet 11090 turned Jerry Small lot really good close tight racing action both days can per sonally vouch quality food available heard nothing praise con dition fieldits size its location think two quotes heard often Yall have best racing facilities around grass field absolutely fantastic shape nice words made feel kinda proud field proud have small part core club members come out work event got meet some super-nice guys see some beautiful planes doin some really competitive racing besides Bob Greer Ill long time talking about Sun day midair yours Take guys put first-class race the field great shape See next month Caudimordax/Taib Continued page 71 wing lift being generated farther out root Very high aspect ratio wings demand extra strength conse quently added weight spars root particular application will demand aspect ratio provides best combi nation weight efficiency Cau dimordax aspect ratio 61 cho sen allowed convenient wing span 48 inches Styrofoam comes 2-ftwide sheetsjust right wing panel mean chord eight inches al lows 10-in root 6-in tip 60% tip/root percentage Such wing core too difficult cut trailing edge swept forward three inches lead ing edge swept back inch producing net sweep quarter-chord zero Experiments straight leading edge produced airplanes unpleasant snap rolling tendencies swept leading edge also allows easier placement spars greater lead-out sweep Eliminating high-speed stall Turning airplane too tightly causes wing stall wing forced produce lift capable producing produce lift angle attack must creased Beyond certain angle attack air flow along top wing separates wings surface becomes turbu lent causing sudden increase drag Most Combat fliers adjust controls limit turn radius order avoid stal ling Another approach use thicker blunter airfoil stalls higher Us thin does drawback ap proach course thicker airfoil has greater parasitic drag top speed reduced accordingly Caudimordax root section thick 15% tip thicker 25% relatively thicker tip airfoil ensures root will stall first turn thus reduc ing airplanes tendency drop wing tip tendency causes lateral instabil ity common high aspect ratio Combat wings Longitudinal stability An airplane does tight fast turns absolutely no use cant make go want go common problem Combat wings lack longitudinal stability turn once started will tighten up its own ac cord makes airplane unpointable therefore useless Combat air plane should also able fly straight unattended An unstable airplane will tend tighten wander out turn pilot glances away inslant common misconception sta 172 Model Aviation SPORTOBATIC 2 84 For1204cycleand 902-cycle rST 200025003000-0 PS 18 NEWOS BGX 13500 bilator elevator make airplane move up down true designer could reduce stabilator area airplane thats overly sensitive unstable Actually opposite true stabilator provides stability opposing downward pitching moment produced wing larger stabilizer larger airplanes stability margin since stabilizer doesnt have work hard Similarly longer tail moment increases stability providing longer moment arm stabilizer act Spitfire airplane too small horizontal stabilizer earlier marks had very small acceptable range CG center-of-gravity ad ditional equipment added aft ac ceptable range aircrafts stability de creased fact several structural failures traced directly aircraft tight ened turns due instability Later war longer range fight ers needed long-range bomber es corts CU became issue again way extending Spitfires range especially bigger Griffon engines used later marks situating addi tional tanks behind pilot Eventually larger horizontal vertical stabilizers incorporated allow rear ward center-of-gravity addition larger tail surfaces helped control 2000-plus horsepower output big Griffon engines 12 x 3-in stabilator shown plans Caudimordax longitudinally sta ble will fly large loops want tightening up set up will turn tightly needed point stalling Earlier versions 9 x 3-in tail predictable Construction center rib tip ribs sta bilator lead-out guide bellcrank plate con trol horn engine mount assembly best cut scroll saw band saw en sure accuracy good fit Final shaping can accomplished belt disc sander sure set up tools cut sand perfect 900 angle prefer band saw scroll saw Most scroll saws dont seem have power cut through maple vibration tends obscure guide marks Band saws comparison powerful very smooth can used resawing balsa pine Have ever worked -in pine Slow fuselages cutting alu minum sheet sawing exhaust lugs off engines really nice l0-in-throat three-wheel band saw can obtained Sears little cost Dremel scroll saw Wait until theyre sale can get Christmas Life terrible before got engine mount assembly first glued together very thick CyA cyanoacrylate glue like Special-T What would Combat fliers super glue Make sure grain both balsa spacer 1/64 ply side plates vertical balsa spacer i/ ply plates may look insubstantial two dowels through maple center rib Ive yet have assemblies fail Trial fit engine mark drill holes engine mount assembly must fitted individually its intended center block marking making diagonal cuts maple Remember allow 1/i6 ply front spar Loose-fitting engine mount/center rib combinations can cor rected adding 1/64 ply spacers needed during final assembly aluminum arrow-shaft tail boom can cut length band saw size use 21/64 0D has 019 walls marked 2117 ought avail able good sporting goods store shafts use cutoffs arrows shortened cost quarter Other sizes well graph ite shafts hard come southern Indiana will work just well Use drill press jig some sort drilling hole back cen ter rib Crooked tails get laughed Drill bits available 44-in increments finding right size shouldnt problem Cut notch rear boom us ing band saw Drill two three holes front inch epoxy anchor before gluing boom block together Shallow notches made band saw will work lieu holes Stuff some tissue paper front end boom pre vent epoxy flowing boom Use slow-curing epoxy Make sure notch back end horizontal Cutting foam cores Most Combat con struction articles will tell look else foam cutting instructions method cutting foam first developed Doc Passen easiest method Ive tried yet cutting bow assembled using 1 x 2-in furring strip cutting wire 015 braided control line power source must able supply 12-13 volts 3-4 amps Variac will work does come cheap use car battery Phil Cartier uses light dimmer switch series 200-watt light bulb Write him Core House 760 Waltonville Road Hummelstown PA 17036 details Root tip templates made out -in-thick Formica edges must sanded smooth possible Candle wax rubbed edges also helps straight cuts Note centerline templates 7/ bottom compen sate fact foam rarely exactly two inches thick also 1/16 lost foam cut Put guide marks templates shown both sides well top guiding edge template patterns edge plans make convenient Xeroxing Paste Xeroxed patterns onto Formica cutting surface prepared driving nails through flat piece plywood par ticle board nails serve hold foam down flat during cutting process should penetrate about inch jig should made cutting blanks Two vertical templates needed edge table 27 apart enough space behind accommodate 8-ft -long foam sheets youre really mass production make jigs two feet high cut dozen blanks once Hold layers foam together bam boo shish kebab skewers skewers also useful holding stacks cut wings beds together storage templates held place using double-pointed pins made %-in alumi num brass welding rod Nails December 1990 173 Fly McDaniel Power New Solid State On-Board Glow-Plug Drivers Now can drive 1 2 glow plugs efficiently automatically new McDaniel On-Board Glow-Plug Drivers engine 2 4 stroke glow has 1 2 cylinders Model 471 472 On-Board Glow-Plug Driver will ease jobs starting maintaining idle during taxiing power down flight maneuvers FEATURES INCLUDE Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Connector Plug Battery Pack Remote Glow Plug Indicator Panels Available Separately Battery Pack AC Charger NOT Included Available Separately See Local Hobby Dealer Cantact McDaniel R/C IncVisa MC accepted 1654 Crofton Blvd Suite 4 Crofton MD 21114 e 3017216303 3017216306 NO OCR TEXT r 1 HALFEANLOCK 24 INCHES PATENT PENDING AT LAST positive connector for I HALF glow heads Fits COX glow heads except 020 Two types ring terminals HEAD LOCK/HEAD LITE II adapter ST#050 RING TERM-$595 ST#051 ADAPTER-$695 F IEY AVAILABLE CIDER DIRLT ADD $100 $200 UPSIDE US 12/89 MODEL PRODUCTS CORPORATION POST OFFICE BOX 100 ALLAMUCHY NJ 07820 FAX 201 850 8860 PHONE201 850 1508 IIIWWII AIRCRAFT SCALE DRAWINGS & SPECIFICATION SHEETS Antiques Military CiviIiar Helicopters Saltptanes 2700 ptvs0000 3-view drawirrpIOser 1200 cele FOTO~ K04CU-FANScrIe 3For Csrsisg RANGER FIBERGLASS RANGER FIBERGLASS CO lss bee, Box 879 spesielizirrg ssstorr design nd nrslding Campton NH tire aerospace industry since 1959 03223 S29 Magnum 28 FSR Royal 28 seems well made 25 FSRs far cry earlier Taiwanese engines Its light weight partially due its AAC piston liner As Brat originally intended RC sport flying its induction timing quite con servative Combat use necessary retime induction port replace RC carburetor large-diameter intake stack also known really venturi also helps trim off excess weight head fins dont contribute very much cooling get way changing glow plugs fins can ground off before disassembling engine Remove glow plug plug hole pieces paper toweling Also plug up air intake ex haust Grind off fins using disc belt sander leaving last 3/ intact Wash off filings detergent wa ter before removing paper towel plugs Disassemble engine cylinder liner fits very tightly case must re moved carefully Dont remove bearings Stuff case paper toweling before grinding off muffler lugs Make sure stuff some toweling down exhaust port disc belt sander good way start file can used inaccessible plac es stone Dremel tool also works will clog needs constant dressing Wash filings off detergent water before pulling out paper toweling care filings will enter engine r OFFICIAL AMA SAFETY CODEJanuary 11991 Model Flying Must Accordance Code Order AMA Liability Protection Apply GENERALflown indoors3 will perform initial turn after takeoff away 1 will fly model aircraft competition 7 will operate models metal-bladed pro- tnt spectator areas will there- U after fly over pit speceae U p spectators until has pellers gaseous boosts gases u p oven o rworthy having previ- other sir normal atmospheric pressure en- yond control ous y successfu y flight testedter internal combustion engines nor will I4 will operate model g ad operate models extremely hazardous fuelsfrequencies currently allowed Federal 2 will fly model higher approxi-such containing tetranitromethane orCommunications Commission Only properly Iimately 400 feet within 3 miles airport with-hydrazinecensed Amateurs authorized operate equip- Out notifying airport operator will give right of-way avoid flying proximity full-8 will operate models pyrotechnics anyment Amateur Bsnd frequencies Further scale aircraft necessary observerdevice explodes burns propels projec-any transmitters use sanctioned eveni shall utilized supervise flying avoid hay-tile kind including limited rock-must have certified R/CMA-AMA gold sticker af ing models fly proximity full-scale aircrafteta explosive bombs dropped modelsfixed indicating manufactured modi- U 3 established will abide safety smoke bombs explosive gases such fled operation 20kHz frequency separaeg site use will willfullyhydrogen-filled balloons ground mounted de-lion except 27MHz 53MHzU d de models careless reck-vices launching projectileThe exceptions permitted rockets flown accordance withFREE FLIGHT less and/or dangerous mannerthe Safety Code National Association 4 mode weighs over 20 pounds will onlyRocketry permanently attached per1 will launch mode c aft un ess Ify t n acco dance paragraph 5 sec-JATO use also items authorized Airleast 100 feet downwind spectato auto tion AMA Safety CodeShow Team use defined AST Advisory Coin-mobile parking 5 air shows model flying demonstrations amittee document available AMA HO Note2 will fly model unless launch area single straight line must established sideA model aircraft defined aircraft orclear persons except mechanic offi flying other side spec-without engine able carry human beingcials I tators Only persons essential flight 9 will fly model using turbojet power ax operations permitted flying sideat centrifugal flowi unless have obtained a3 will employ use adequate dev ce n line others must spectatorspecial waiver such specific flights theflight extinguish fuses mode afte de F g spectator side line isAMA President Executive Director willhas completed its function Ip b e beyond control theabide restrictions imposed such flights pilots exceptions may permitby Note does apply ducted fanCONTROL LINE Ited single straight line requirement undermodels using piston engines electric motors special circumstances involving consideration of11 will subject comp m site conditions model size weight speedRADIO CONTROLcluding safety thong applicable inand power must jointly approved AMAspection pull test prior flying President Executive Director maxi-1 twill have completed successful radio equipmum permissible takeoff weight models 55ment ground range check before first flight of21 will assure flying area safely clear Ilbsa new repaired modelof utility wires poles 6 will fly model unless identified with2 will fly model aircraft presence3 will assure fly g a name address AMA number inof spectators until become qualified flier un-of non-essential participants spectators model Note does apply modelsless assisted experienced helperbefore permitting engine started make sure wash out case thoroughly An old toothbrush helps Thoroughly dry oil bearings As stated earlier intake port crankshaft must opened up increase angle remains open Before retiming crank scratch tim ing diagram shown plans onto piece transparent rigid plastic using scribe Thin Plexiglas should work well Insert crankshaft case Slipping drive washer prop nut will help hold shaft proper position Holding engine nose down lay tim ing diagram onto rear engine Line up cross hairs bottom mounting lugs mold flashing centerline engine Referring figure lA rotate shaft un til middle crankpin lines up opening line holding crankshaft position insert hard metal scribe through intake stack make mark crank Use bottom edge frft looking rear side intake port crankcase guide youve set up correctly port should totally closed off shaft doing likewise closing side take port referring figure lB time make mark right side port intake stack can made /2-inOD aluminum nylon brass tubing wall thickness should /32 /16 Wrap Teflon tape around tube ensure good seal intend use remote needle drill tap 6-32 Du-Bro pressure fitting 1/ above stack slips case remote needle made 05 RC needle valve assembly mounted engine bearers using nylon control horn 2-56 sheet metal screws Wash engine parts using hot water dishwashing detergent Dry off parts us ing paper toweling Oil parts WD 40 Break-Free reassemble engine Flying Caudimordax flies best CU line spars using about four five pennies tip weight approximately 13-16 grams Attach streamer test flying Line rake usually set maximum two rearmost holes lead-out guide Brats seem like 7 x 6 Taipan props use 25% Red Max fuel half castor half synthetic oil back-flipping chickenstick technique described Charlie Johnson Combat column seems work best quick starts flying airplane first time check warps Fly level upright note whether either wing appears flying high outboard wing higher inboard very carefully flip airplane onto its back outboard wing flies low have warp still flies high add tip weight outboard wing flies low upright high inverted have warp other way Dont tight turns warped air plane Take home use heat gun shrink covering needed eliminate warp flying against faster opponent use Caudimordaxs superior turning radius advantage Follow opponent through turns advantage level speed negated have actually able fly up others tail pipes occasion Always lookout leading edge kill opponent makes pass streamer often sets him up overshoot thats leading edge kill can ac complished name Caudimordax Doc Passen calls Quasimodo comes Tolkiens book Farmer Giles Ham Naming Combat de signs after weapons named Tolkiens bet ter known book Lord Rings old tra dition Combat circles Orcrist Andu ril English FAI designs instance Glamdring Guthwine Aeglos still up grabs Sting would make good name Anglachel though wouldnt appropriate airplane hope will fly Caudimordax however uniquely appro priate Combat airplane sword also known vulgar tongue Tailbiter habit leaping out its sheath whenever dragon near tra dition time knights kill dra gons cut off tails serve delicacy court sword given Farmer Giles put good use Further development As Combat designs Caudimordax anything static Combat designs evolve faster due high rate destruction Dont afraid try out different airfoils different tail mo ments different construction techniques Per ryman tips Ford Taurus styling Steve Hills Arrowplane wont will can stick Fox 36 nose please use least 34-in-thick wood center block 3/4 x 3A-in maple engine mounts never build Caudimordax article others ought give few ideas improve other design design own Nearly construction techniques used airplane filched others Id like thank too ideas used design Terry Doc Passen foam cutting engine retiming techniques tail hinge bellcrank mount pushrod Phil Cartier arrow-shaft tail boom techniques bladder compartment idea using smaller engines first place Rich ard Wilkens front spar foam cutting bow CL Scale/Boss Continued page 72 Ontario Canada CL Scale judged June 30th flown July 1st Mike reports disappointing CL Scale entry five Two Canadians other three US Its surprising US modelers north central area country werent hand com petition contest site about three hours Buffalo NY about two hours Detroit MI well within days drive several north central statesContinued page 178 December 1990 177 DOE Z2Li2 TNROFILES AND SUPPLIES FOR ELECTRIC FLIGHT SM5 1 6 cells tu u amps SM4 7 23 cells 50 amps Sc6 24 34 cells 60 amps -all throttles linear proportional forward only#15 WiRE 350 STRAND 020 25 size #12 WIRE 665 STRAND 25 100 siz Toas ac4da6ge s 44ff Call write JOMAR 513-474-0985 2028 Knightsbridge Dr. Cincinnati OH 45244
Edition: Model Aviation - 1990/12
Page Numbers: 68, 69, 70, 71, 172, 173, 174, 176, 177
Caudimordax Fast Combat smaller engines works Three ounces fuel can last up five minutes shoulder stays piece slower tight-turning ship gives edge over opponentand engine costs lot less Hlskandar Taib AMERICAN COMBAT design philosophy has traditionally favored speed over turning ability Note large sums money spent Hoffelts custom Foxes bolted onto 300- 400-sq-in airplanes weighing 21 oz What en gines share besides enormous power output weight Most weigh about 9/2 oz Caudimordax design takes other approach high rate turn small turning radius given top priority qualities achieved using light engine high aspect ratio wing compromise speed Caudimordax Brat 28 flies 10 15 mph slower level flight typical Fast Combat job makes up turns though much tighter actually slow down ship much less would heavier model Flying Fast Combat smaller engines has other advantages Three ounces fuel Left left unmodified Brat 28 stIll sporting its RC carburetor author has several give away right modified Brat 28 Note missing metal around exhaust port thinned head fins homemade venturi 7 x 6 Talpal prop Right Close-up view remote needle valve assembly unit OS 10 FSR RC used Note short length tubing slipped over end needle valve prevent leakage plastic clip fuel line available author 68 Model Aviation Author/builder Iskandar Taib holding Caudimordax thoroughly designed Combat plane gives up some top speed typically 10-15 mph makes up barely slowing corners Light weight along special modifications engine make possible Left Mark made crankshaft intake ports closing side Right Mark made opening side Note amount metal has removed Brats have very conservative timing befits its sport RC roots Left Front end tail boom Note shallow cuts made aluminum epoxy grab Small holes may drilled instead Right Engine mount assembly center rib Mount marked sawing using front center rib pattern ft Components horizontal stabilizer Start epoxying arrow shaft stab anchor Glue hinge assembly stab anchor cover horizontal stab -In medium balsa glue stab anchor Right completed tail assembly Notice hinge built String wrapped figure-eight pattern around two 3As dowels December 1990 69 F 4 4 \ - will last five minutes airplane doesnt dislocate shoulder its fast cant keep up slower tight-turning airplane can also hard opponent line up have gotten several kills other guy overshot attack Perhaps important engines cost far less bigger counterparts Caudimordax can also used Out law FAJ contests sprouting up over Midwest Rules typically specify Fast Slow rules 15 engines 52-ft lines no restrictions engine tank setups nitro content fuel Most Schnuerle-ported double ball bear ing 15s weigh about six ounces 34 oz less Brat 28 modifications needed use slightly smaller typically l/ engine bearer spacing mount engine slightly further ward Caudimordax design goes back sev eral years evolving slowly its present form admittedly incorporating features currently vogue External con trols instance now being used top fliers including Russians save much building time allowing use solid wing panels Another great time-saver simple cutout blad der tank replaces common rocket tube arrow-shaft tail boom al though requires little extra building time allows easier rebuilding saves little weight agility Caudimordax attribut able its high aspect ratio wing thick airfoil high aspect ratio reduces tip vortices cause induced drag thick airfoil delays onset high-speed stall thick airfoil also lends lateral sta FAST COMBAT DESIGN ESR 23-32 ENGINES bility design helps control snap rolling associated high aspect ratio designs Induced drag Just what induced drag its reduction important Combat design Drag generally divided two types often confused Parasitic drag caused friction air surface airplane therefore proportional surface area wing Also included category drag lines drag caused protuberances airplane such pushrod engine cylinder Streamlining serves reduce parasitic drag Induced drag other hand re lated lift produced wing wing producing lift pressure air bottom surface wing greater pressure top pressure differences cause air above wings move outward toward wing tips air below wings move toward root tips nothing pre vent air below wings curling around tips pushing down top surface wing reducing actual amount lift produced airflow around wing tip also pro duces turbulent vortices often visible va por trails emanating wing tips jet fighters during high-G maneuvers energy needed drive vortices ulti mately Linked drag drag sociated vortices de scribed induced drag greater lift 70 Model Aviation Pushrod braces made outer Sullivan Ny-Rod Filament tape wraps tail boom bed nails particular piece made out straight section chip-core board Full-Size Plans Available. Page 200 nI 1~ ** TJ / produced wing larger vor tices Several strategies exist reduction tip vortices Tip fences instance will impede air flowing around wing tips Low aspect ratio wings would benefit tip fences Ed Brzys listen ing Theyve seen full-scale air planes low aspect ratio wings such pretty Racing biplane Sorceress Hoer ner anti-vortex tips variation tip fence shaped force airflow tips counter direction tip vor tex However work air plane experiences positive Gs Flip air plane its back anti-vortex tips ac tually add problem Forward sweep wing causes air flow move toward root can spill cause vortex forward swept wings have extremely rigid withstand aeroelastic twisting forces increase wing twists technically known aeroelastic divergence Another way improve efficiency lift/drag ratio wing use smaller wing tip Wind tunnel experiments have shown Schuemann planform shouldnt called George Perryman planform currently vogue glider pi lots has least amount induced drag given amount lift elliptical planform eg Spitfire almost good wing no taper 60% 65% efficient elliptical wing same pect ratio wing tip chord 60% 65% root chord 90% 95% efficient turn tapered wing produces lot less induced drag nontapered High aspect ratio wings have smaller amounts tip spillage low aspect ratio wings less wing tip length per unit area Glider wings have high aspect ratios very purpose High aspect ratio wings have own problems however main being added bending stresses put Continued page 172 Left Cutting top surface wing core Core held tightly board embedded nalis Note bow held Right Cutting spar slot Slot cut single pass down back up Author gives complete directions foam wing cutting something rarely done December 1990 71 / 7- design drawing Nur Iskandar Taib modela fill need hotdog show-off sport plane Knife edge take-offs flat apins snaps anything can Wing foam Fuselage Tail lite ply balsa Builds quick lands like trainer Flyingweight lOlba 184 1 l3lbs 192 Ohio OHIO SUPERSTAR PRODUCTS INC 11376 RIOGEWAY ROADKENSINGTON OHIO 44427 r 216-223-1950 great idea cant resist quoting Mr Stahls comments opening paragraph Overemphasis strictly flying designs con tests throughout country recent years has brought about unwarranted condition ne glect building flying Scale semiscale models Much favoritism must tributed desire maximum performance since little need said relative appearance neatly built Scale ship usual contest design SAM Italia Dr Ferdinando Gale Baveno aly recently sent interesting handbook about Eastern bloc engines written Cesare de Robertis Well illustrated unusual model power plants text Italian available Gale Via Marconi 10 28042 Baveno NO Italy interesting material de signs emerging SAM Italia including several magnificent construction drawings beautiful Italian Gliders pre-WW II era available B2 Streamlines PO Box 976 Olalla WA 98359 RC Pylon/Hager Continued page 64 no mediocre planes event fact well done dont know pilots selected would show two three brought along would still out trying decide Id vote collection absolutely beautiful takeoff area too narrow support four planes up heats threeplane blasts Plans have made things works widen takeoff area fourplane heats can accommodated next spring top 10 finishers Saturday 1 Randy Rich 11480 2 Richard Oliver 11701 3 Red Cranfield 12189 4 Phil Bussell 11742 5 Jim Young 11859 6 Bill Hager 11539 7 Hubert Wills 11905 8 Norm Johnson 11473 9 Dub Jets 11487 10 Sam Womack 11656 Just keep everyones attention two midairs Saturday both occurring just out turn number three Poor Bob Greer par ticipant little high-speed tangos Dave Layman Bill Hager Jerry Small tried trade little paint flight wound up getting planes dirty easier transport under seat Sundays action just hot heavy make sure moves down pat Bob Greer provided present what violent midair collision since vention prop happened about 20 ft di rectly behind above head stood cage turn number pilot lane made clock locked ac tion happened felt bad pilots crash itself right out movies another midair just out turn number three tame comparison Bob Greer/Hubert Wills fiasco earlier com pletely forgot get names pilots volved Yours Truly Bill Hager Jerry SmallBH Top five finishers Sunday 1 Dub Jett 11685 2 Red Cranfield l193 Phil Bussell 12059 4 Bill Hager 11614 5 Montie Montcrief 11620 6 Clay Gary 11509 7 Dave Layman 11381 8 Norm Johnson 11415 9 Randy Ritch 11529 10 Sam Wo mack 12772 Fast time meet 11090 turned Jerry Small lot really good close tight racing action both days can per sonally vouch quality food available heard nothing praise con dition fieldits size its location think two quotes heard often Yall have best racing facilities around grass field absolutely fantastic shape nice words made feel kinda proud field proud have small part core club members come out work event got meet some super-nice guys see some beautiful planes doin some really competitive racing besides Bob Greer Ill long time talking about Sun day midair yours Take guys put first-class race the field great shape See next month Caudimordax/Taib Continued page 71 wing lift being generated farther out root Very high aspect ratio wings demand extra strength conse quently added weight spars root particular application will demand aspect ratio provides best combi nation weight efficiency Cau dimordax aspect ratio 61 cho sen allowed convenient wing span 48 inches Styrofoam comes 2-ftwide sheetsjust right wing panel mean chord eight inches al lows 10-in root 6-in tip 60% tip/root percentage Such wing core too difficult cut trailing edge swept forward three inches lead ing edge swept back inch producing net sweep quarter-chord zero Experiments straight leading edge produced airplanes unpleasant snap rolling tendencies swept leading edge also allows easier placement spars greater lead-out sweep Eliminating high-speed stall Turning airplane too tightly causes wing stall wing forced produce lift capable producing produce lift angle attack must creased Beyond certain angle attack air flow along top wing separates wings surface becomes turbu lent causing sudden increase drag Most Combat fliers adjust controls limit turn radius order avoid stal ling Another approach use thicker blunter airfoil stalls higher Us thin does drawback ap proach course thicker airfoil has greater parasitic drag top speed reduced accordingly Caudimordax root section thick 15% tip thicker 25% relatively thicker tip airfoil ensures root will stall first turn thus reduc ing airplanes tendency drop wing tip tendency causes lateral instabil ity common high aspect ratio Combat wings Longitudinal stability An airplane does tight fast turns absolutely no use cant make go want go common problem Combat wings lack longitudinal stability turn once started will tighten up its own ac cord makes airplane unpointable therefore useless Combat air plane should also able fly straight unattended An unstable airplane will tend tighten wander out turn pilot glances away inslant common misconception sta 172 Model Aviation SPORTOBATIC 2 84 For1204cycleand 902-cycle rST 200025003000-0 PS 18 NEWOS BGX 13500 bilator elevator make airplane move up down true designer could reduce stabilator area airplane thats overly sensitive unstable Actually opposite true stabilator provides stability opposing downward pitching moment produced wing larger stabilizer larger airplanes stability margin since stabilizer doesnt have work hard Similarly longer tail moment increases stability providing longer moment arm stabilizer act Spitfire airplane too small horizontal stabilizer earlier marks had very small acceptable range CG center-of-gravity ad ditional equipment added aft ac ceptable range aircrafts stability de creased fact several structural failures traced directly aircraft tight ened turns due instability Later war longer range fight ers needed long-range bomber es corts CU became issue again way extending Spitfires range especially bigger Griffon engines used later marks situating addi tional tanks behind pilot Eventually larger horizontal vertical stabilizers incorporated allow rear ward center-of-gravity addition larger tail surfaces helped control 2000-plus horsepower output big Griffon engines 12 x 3-in stabilator shown plans Caudimordax longitudinally sta ble will fly large loops want tightening up set up will turn tightly needed point stalling Earlier versions 9 x 3-in tail predictable Construction center rib tip ribs sta bilator lead-out guide bellcrank plate con trol horn engine mount assembly best cut scroll saw band saw en sure accuracy good fit Final shaping can accomplished belt disc sander sure set up tools cut sand perfect 900 angle prefer band saw scroll saw Most scroll saws dont seem have power cut through maple vibration tends obscure guide marks Band saws comparison powerful very smooth can used resawing balsa pine Have ever worked -in pine Slow fuselages cutting alu minum sheet sawing exhaust lugs off engines really nice l0-in-throat three-wheel band saw can obtained Sears little cost Dremel scroll saw Wait until theyre sale can get Christmas Life terrible before got engine mount assembly first glued together very thick CyA cyanoacrylate glue like Special-T What would Combat fliers super glue Make sure grain both balsa spacer 1/64 ply side plates vertical balsa spacer i/ ply plates may look insubstantial two dowels through maple center rib Ive yet have assemblies fail Trial fit engine mark drill holes engine mount assembly must fitted individually its intended center block marking making diagonal cuts maple Remember allow 1/i6 ply front spar Loose-fitting engine mount/center rib combinations can cor rected adding 1/64 ply spacers needed during final assembly aluminum arrow-shaft tail boom can cut length band saw size use 21/64 0D has 019 walls marked 2117 ought avail able good sporting goods store shafts use cutoffs arrows shortened cost quarter Other sizes well graph ite shafts hard come southern Indiana will work just well Use drill press jig some sort drilling hole back cen ter rib Crooked tails get laughed Drill bits available 44-in increments finding right size shouldnt problem Cut notch rear boom us ing band saw Drill two three holes front inch epoxy anchor before gluing boom block together Shallow notches made band saw will work lieu holes Stuff some tissue paper front end boom pre vent epoxy flowing boom Use slow-curing epoxy Make sure notch back end horizontal Cutting foam cores Most Combat con struction articles will tell look else foam cutting instructions method cutting foam first developed Doc Passen easiest method Ive tried yet cutting bow assembled using 1 x 2-in furring strip cutting wire 015 braided control line power source must able supply 12-13 volts 3-4 amps Variac will work does come cheap use car battery Phil Cartier uses light dimmer switch series 200-watt light bulb Write him Core House 760 Waltonville Road Hummelstown PA 17036 details Root tip templates made out -in-thick Formica edges must sanded smooth possible Candle wax rubbed edges also helps straight cuts Note centerline templates 7/ bottom compen sate fact foam rarely exactly two inches thick also 1/16 lost foam cut Put guide marks templates shown both sides well top guiding edge template patterns edge plans make convenient Xeroxing Paste Xeroxed patterns onto Formica cutting surface prepared driving nails through flat piece plywood par ticle board nails serve hold foam down flat during cutting process should penetrate about inch jig should made cutting blanks Two vertical templates needed edge table 27 apart enough space behind accommodate 8-ft -long foam sheets youre really mass production make jigs two feet high cut dozen blanks once Hold layers foam together bam boo shish kebab skewers skewers also useful holding stacks cut wings beds together storage templates held place using double-pointed pins made %-in alumi num brass welding rod Nails December 1990 173 Fly McDaniel Power New Solid State On-Board Glow-Plug Drivers Now can drive 1 2 glow plugs efficiently automatically new McDaniel On-Board Glow-Plug Drivers engine 2 4 stroke glow has 1 2 cylinders Model 471 472 On-Board Glow-Plug Driver will ease jobs starting maintaining idle during taxiing power down flight maneuvers FEATURES INCLUDE Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Connector Plug Battery Pack Remote Glow Plug Indicator Panels Available Separately Battery Pack AC Charger NOT Included Available Separately See Local Hobby Dealer Cantact McDaniel R/C IncVisa MC accepted 1654 Crofton Blvd Suite 4 Crofton MD 21114 e 3017216303 3017216306 NO OCR TEXT r 1 HALFEANLOCK 24 INCHES PATENT PENDING AT LAST positive connector for I HALF glow heads Fits COX glow heads except 020 Two types ring terminals HEAD LOCK/HEAD LITE II adapter ST#050 RING TERM-$595 ST#051 ADAPTER-$695 F IEY AVAILABLE CIDER DIRLT ADD $100 $200 UPSIDE US 12/89 MODEL PRODUCTS CORPORATION POST OFFICE BOX 100 ALLAMUCHY NJ 07820 FAX 201 850 8860 PHONE201 850 1508 IIIWWII AIRCRAFT SCALE DRAWINGS & SPECIFICATION SHEETS Antiques Military CiviIiar Helicopters Saltptanes 2700 ptvs0000 3-view drawirrpIOser 1200 cele FOTO~ K04CU-FANScrIe 3For Csrsisg RANGER FIBERGLASS RANGER FIBERGLASS CO lss bee, Box 879 spesielizirrg ssstorr design nd nrslding Campton NH tire aerospace industry since 1959 03223 S29 Magnum 28 FSR Royal 28 seems well made 25 FSRs far cry earlier Taiwanese engines Its light weight partially due its AAC piston liner As Brat originally intended RC sport flying its induction timing quite con servative Combat use necessary retime induction port replace RC carburetor large-diameter intake stack also known really venturi also helps trim off excess weight head fins dont contribute very much cooling get way changing glow plugs fins can ground off before disassembling engine Remove glow plug plug hole pieces paper toweling Also plug up air intake ex haust Grind off fins using disc belt sander leaving last 3/ intact Wash off filings detergent wa ter before removing paper towel plugs Disassemble engine cylinder liner fits very tightly case must re moved carefully Dont remove bearings Stuff case paper toweling before grinding off muffler lugs Make sure stuff some toweling down exhaust port disc belt sander good way start file can used inaccessible plac es stone Dremel tool also works will clog needs constant dressing Wash filings off detergent water before pulling out paper toweling care filings will enter engine r OFFICIAL AMA SAFETY CODEJanuary 11991 Model Flying Must Accordance Code Order AMA Liability Protection Apply GENERALflown indoors3 will perform initial turn after takeoff away 1 will fly model aircraft competition 7 will operate models metal-bladed pro- tnt spectator areas will there- U after fly over pit speceae U p spectators until has pellers gaseous boosts gases u p oven o rworthy having previ- other sir normal atmospheric pressure en- yond control ous y successfu y flight testedter internal combustion engines nor will I4 will operate model g ad operate models extremely hazardous fuelsfrequencies currently allowed Federal 2 will fly model higher approxi-such containing tetranitromethane orCommunications Commission Only properly Iimately 400 feet within 3 miles airport with-hydrazinecensed Amateurs authorized operate equip- Out notifying airport operator will give right of-way avoid flying proximity full-8 will operate models pyrotechnics anyment Amateur Bsnd frequencies Further scale aircraft necessary observerdevice explodes burns propels projec-any transmitters use sanctioned eveni shall utilized supervise flying avoid hay-tile kind including limited rock-must have certified R/CMA-AMA gold sticker af ing models fly proximity full-scale aircrafteta explosive bombs dropped modelsfixed indicating manufactured modi- U 3 established will abide safety smoke bombs explosive gases such fled operation 20kHz frequency separaeg site use will willfullyhydrogen-filled balloons ground mounted de-lion except 27MHz 53MHzU d de models careless reck-vices launching projectileThe exceptions permitted rockets flown accordance withFREE FLIGHT less and/or dangerous mannerthe Safety Code National Association 4 mode weighs over 20 pounds will onlyRocketry permanently attached per1 will launch mode c aft un ess Ify t n acco dance paragraph 5 sec-JATO use also items authorized Airleast 100 feet downwind spectato auto tion AMA Safety CodeShow Team use defined AST Advisory Coin-mobile parking 5 air shows model flying demonstrations amittee document available AMA HO Note2 will fly model unless launch area single straight line must established sideA model aircraft defined aircraft orclear persons except mechanic offi flying other side spec-without engine able carry human beingcials I tators Only persons essential flight 9 will fly model using turbojet power ax operations permitted flying sideat centrifugal flowi unless have obtained a3 will employ use adequate dev ce n line others must spectatorspecial waiver such specific flights theflight extinguish fuses mode afte de F g spectator side line isAMA President Executive Director willhas completed its function Ip b e beyond control theabide restrictions imposed such flights pilots exceptions may permitby Note does apply ducted fanCONTROL LINE Ited single straight line requirement undermodels using piston engines electric motors special circumstances involving consideration of11 will subject comp m site conditions model size weight speedRADIO CONTROLcluding safety thong applicable inand power must jointly approved AMAspection pull test prior flying President Executive Director maxi-1 twill have completed successful radio equipmum permissible takeoff weight models 55ment ground range check before first flight of21 will assure flying area safely clear Ilbsa new repaired modelof utility wires poles 6 will fly model unless identified with2 will fly model aircraft presence3 will assure fly g a name address AMA number inof spectators until become qualified flier un-of non-essential participants spectators model Note does apply modelsless assisted experienced helperbefore permitting engine started make sure wash out case thoroughly An old toothbrush helps Thoroughly dry oil bearings As stated earlier intake port crankshaft must opened up increase angle remains open Before retiming crank scratch tim ing diagram shown plans onto piece transparent rigid plastic using scribe Thin Plexiglas should work well Insert crankshaft case Slipping drive washer prop nut will help hold shaft proper position Holding engine nose down lay tim ing diagram onto rear engine Line up cross hairs bottom mounting lugs mold flashing centerline engine Referring figure lA rotate shaft un til middle crankpin lines up opening line holding crankshaft position insert hard metal scribe through intake stack make mark crank Use bottom edge frft looking rear side intake port crankcase guide youve set up correctly port should totally closed off shaft doing likewise closing side take port referring figure lB time make mark right side port intake stack can made /2-inOD aluminum nylon brass tubing wall thickness should /32 /16 Wrap Teflon tape around tube ensure good seal intend use remote needle drill tap 6-32 Du-Bro pressure fitting 1/ above stack slips case remote needle made 05 RC needle valve assembly mounted engine bearers using nylon control horn 2-56 sheet metal screws Wash engine parts using hot water dishwashing detergent Dry off parts us ing paper toweling Oil parts WD 40 Break-Free reassemble engine Flying Caudimordax flies best CU line spars using about four five pennies tip weight approximately 13-16 grams Attach streamer test flying Line rake usually set maximum two rearmost holes lead-out guide Brats seem like 7 x 6 Taipan props use 25% Red Max fuel half castor half synthetic oil back-flipping chickenstick technique described Charlie Johnson Combat column seems work best quick starts flying airplane first time check warps Fly level upright note whether either wing appears flying high outboard wing higher inboard very carefully flip airplane onto its back outboard wing flies low have warp still flies high add tip weight outboard wing flies low upright high inverted have warp other way Dont tight turns warped air plane Take home use heat gun shrink covering needed eliminate warp flying against faster opponent use Caudimordaxs superior turning radius advantage Follow opponent through turns advantage level speed negated have actually able fly up others tail pipes occasion Always lookout leading edge kill opponent makes pass streamer often sets him up overshoot thats leading edge kill can ac complished name Caudimordax Doc Passen calls Quasimodo comes Tolkiens book Farmer Giles Ham Naming Combat de signs after weapons named Tolkiens bet ter known book Lord Rings old tra dition Combat circles Orcrist Andu ril English FAI designs instance Glamdring Guthwine Aeglos still up grabs Sting would make good name Anglachel though wouldnt appropriate airplane hope will fly Caudimordax however uniquely appro priate Combat airplane sword also known vulgar tongue Tailbiter habit leaping out its sheath whenever dragon near tra dition time knights kill dra gons cut off tails serve delicacy court sword given Farmer Giles put good use Further development As Combat designs Caudimordax anything static Combat designs evolve faster due high rate destruction Dont afraid try out different airfoils different tail mo ments different construction techniques Per ryman tips Ford Taurus styling Steve Hills Arrowplane wont will can stick Fox 36 nose please use least 34-in-thick wood center block 3/4 x 3A-in maple engine mounts never build Caudimordax article others ought give few ideas improve other design design own Nearly construction techniques used airplane filched others Id like thank too ideas used design Terry Doc Passen foam cutting engine retiming techniques tail hinge bellcrank mount pushrod Phil Cartier arrow-shaft tail boom techniques bladder compartment idea using smaller engines first place Rich ard Wilkens front spar foam cutting bow CL Scale/Boss Continued page 72 Ontario Canada CL Scale judged June 30th flown July 1st Mike reports disappointing CL Scale entry five Two Canadians other three US Its surprising US modelers north central area country werent hand com petition contest site about three hours Buffalo NY about two hours Detroit MI well within days drive several north central statesContinued page 178 December 1990 177 DOE Z2Li2 TNROFILES AND SUPPLIES FOR ELECTRIC FLIGHT SM5 1 6 cells tu u amps SM4 7 23 cells 50 amps Sc6 24 34 cells 60 amps -all throttles linear proportional forward only#15 WiRE 350 STRAND 020 25 size #12 WIRE 665 STRAND 25 100 siz Toas ac4da6ge s 44ff Call write JOMAR 513-474-0985 2028 Knightsbridge Dr. Cincinnati OH 45244