BANZAI UPDATE couple columns ago pictured talked about Banzai Slope Soarer being kitted Jerry Teo Since time Banzai has undergone number changes now being kitted Banzai Mk II following notable changes original design fuselage has plywoodreinforced /5-in balsa sides wing includes spruce spar durability resistance flex damage kit now features better instruc tions scale drawings According Jerry kit retains high qual ity prefabrication materials its along introductory price will $28 US plus $350 per kit shipping han dling Jerry also mentioned Banzai Enterprises planning bringing out several kits near future following list Slope de signs firm working Combat Aero batic Delta Wing Pattern-like FAt ship BD-5 F-20 semiscale Tigershark both Unlim ited One-Meter Slope Racers Sounds great huh Drop Jerry line let him know kits youd like see first Write him Banzai Enterprises 2997 Anderson Ave Port Alberni British Columbia V9Y 2V3 Cana da Photo mix-up seems captions two photos July column mixed up has little bit confusion cause Please note captions photos Mike Reeds Slopar Banzai Enter prises Banzai inadvertently reversed Apol ogies concerned confused Torrey Pines Scale Fun-Fly would like chance fly Americas best-known slopes some countrys enthusias tic Scale fliers chance Thanksgiving weekend November 24-26 1989 tradi tion National Scale Slope Soaring Fun-Fly held past two years Tn-Cities WA event will three days pure Scale Soaring addition regular flying Charlie Money PR man fun-fly editor Slope Soar jog News scheduling Scale Glider demonstra tions during weekend Various manufacturers will fly planes talk about show off kits well answer questions As Charlie puts demos will entertain ing pilots spectators theyll formative interested kit buyers theyll help struggling garage-shop industry make few sales Sounds like great idea Charlie compiling mailing list interested fliers youd like get little informa tion Torrey Pines Gulls Scale Fun-Fly send name address phone number Charlie Morey Slope Soaring News 2601 E 19th Street #29 Signal Hill CA 90804 Penetrator update During recent phone call John Fotiu JM Glascraft got longawaited news larger version Penetra tor works Being about 50% larger original new version will ideal larger slopes like Eagle Butte Richland WA Coyote Hills northern California cant wait ballast up send Out 30plus lift John also has great-looking Mirage III delta wing Therell future column info Mirage new Pene trator contact John JM Glascraft 30820 May flower Roseville MI 48066 596060a better Eppler 374 Anyone has spent much time slopes has come across Eppler 374 form another Known Slope Soarers airfoil 374 has part sport years recent edition Slope Soaring Newr Charlie Money took look epic airfoil its newly derived cousin Selig-Donovan 6060 Eppler 374 semisymmetnical airfoil Slope Soaring standard Its fast offers Left Although best known being member national F3B team past four years Rich Spicer also avid Sloper Nova designed number years ago still potent Racer Right Designed unbridled speed mind Ken Gregorys Renegade reg ular California Slope Racing circuit Kens leader composite construction all-glass Renegade great example work 54 Model Aviation Radio Control Slope Soaring Mark Triebes 20794 Kreisier Cc Saratoga CA 95070 Torrey Pines No might see Scale ships like gorgeous five-meter LS-1 Tar ray Pines Scale Fun Fly held Thanksgiving weekend Photo Sailpianes International Also located NWSS booth Puyallup Gene Copes Spitfire P55 has grown leaps bounds last year Torrey Pines Scale Fun Fly will show case PSS kits Photo Wil Byers good inverted performance Aerobatics Its popular airfoils use custom Slope Racing ships Its also modified airfoils Dr Epplers stable Almost Sailplane de signer whos played 374 has found way another improve Its thinned tweaked tossed turned tilted inter est making better already Although everyone tinkers 374 attempts limited resources Typ ical approaches trial error seat-of-thepants design eyeball engineering ubiqui tous TLAR Looks About Right Only recent months has someone higher education engineering specif ically low Reynolds number aerodynamic de sign taken 374 wind tunnel analyzed its shortcomings made specific corrections eliminate Perhaps youve heard Michael Seligs air foils Seligs S3021 used Mark Allens Fal con 880 conjunction S3014 tip Mike Reeds Slopar pop ular Again its improved Eppler time popular 205 both casesthe 205 now 374 Selig decreased amount drag produced Eppler airfoils maintaining other wise similar profile June 5-7 1989 Conference Low Reynolds Numbers Aerodynamics took place University Notre Dame confer ence paper called Low Reynolds Number Air foil Design Wind Tunnel Testing Prince ton University presented J F Donovan M S Selig Mr Donovan research scientist McDonnell Douglas Research Laboratories St Louis Mr Selig graduate student Pennsyl vania State University extensive back ground model aircraft airfoil design Michael Selig kind enough provide Slope Soaring News copy paper So dictionary hand six-pack nearby Ive attempted summarize translate technicalese modelers English goes Okay lets start beginning Whats Reynolds number Its means specifying airflow over wing Reynolds numbers stated scientific notationeg 30 x 105—and refer number air molecules flowing across wing Simply put larger number air flows over wing Scientific notation allows us write very Continued page 160 Another First McDaniel RICI New Solid State On-Board Glow-Plug Drivers Now can drive ito 9 glow plugs efficiently automatically new McDaniel On-Board Glow-plug Drivers engine 2 or4 stroke glow has ito 9 cylinders On-Board Glow-Plug Drivor will ease job start ing maintaining idle during taxiing power down flight maneuvers Features Include Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Drive Up 9 Cylinders 48V 500 mAh Batteryt Includes Battery Connector & Wire Jim Rauchs slick F-4 Phantom P55 ship PuVallup Expo Photograph Wil Byers Model 475 Stiewn Optional Battery Pack Jim Magnuson duplicated paint job full-scale P-51 Obsession Word John Fotiu JM Glascrafta larger Penetra tor works Photo Jim Magnuson Another innovation McDaniel RIC kunning Time Increased Larger Battery HANDSOFFCUTII Especially Designed Tapered Wings unique device cutting high quality foam wing cores HANDS OFF cutting both sides lye same time Available hardware package assemble own board Specify 30 40 50 60 ordering Size may changed anytime Man Chord 18 standard Larger chords available Easy assemble Requires 24 Volt Variable Output Power Supply DEALERS WANTED Hands Off Cut II hardware package$87 SO 5 5 H 24 Volt Variable Output power supply 50 5 & H VIDEO FOAM SHOP Foam Shop Part OneCutting Foam Wings sour long cuts made using HANDS OFF CUT IiV H 5Only $2955 includes 5 & H lowei 48 Foam Shop Part TwoCutting Foam Fuselages hour long cuts made using simple bow VHSOnly 52995 includes 5 & H Id ei 48 SUPER BOND ACT ADHESIVE best contact cement have ever used Onip $375 8 oc squeeze bottle Enough 1400 square soC wingAdd $300 S & H lower 48 1/8 inch Phenolic Board Templates 4 X36tos ItOnly $500 * $200S & H NOR-RAY PRODUCTS Sasdbeach Road Wichita Pails Tevas 7831 Tel 8171 6924476 December 1989 55 Just time Christmas TeleHobbies R/C Network Just call 703 709-8554 favorite computer communications software RIC information electronic ordering Sign now avoid rush registration fee NO USAGE CHARGE Help design R/C hobby network want future RC supplies shipped immediately door 800 numbers coming next year RC Slope Soaring/Triebes Continued page 55 large numbers relatively brief manner example 30 x lO5 three times 10 fifth power 300000 As can see its partic ularly useful such small number get up whole number has about 72 zeros after its much easier write 30 x 1072 list 72 zeros time write number Low Reynolds numbers defined Selig-Donovan paper 500000 less wind tunnel tests slow medium fast read ings taken 60000 100000 300000 numbers very low compared associated full-scale powered aircrafthence low Reynolds Number Aero dynamics conference distinguishing characteristic air foil operated low chord Reynolds numbers Re 50 x l0 formation extensive laminar separation bubble either upper lower surfaces both bubble can signifi cantly increase drag quote pretty much sums up entire story SD6060 As air flows over top Eppler 374 breaks away sur face just past high point wing reat taches later back near trailing edge middle beneath layer detached air bub ble turbulent air forms Recognizing bubble source drag Selig set out design new airfoil minimizes drag reshaping 374 slightly Selig de creased size bubble moved ward laminar airflow could reattach wing surface sooner resulted de crease drag improved airfoil performance Does mean SD6060 will replace Eppler 374 new Slope Soaring stan dard performs well hillside did wind tunnel think will Please try let us know about results Let know tooMT Seligs wind tunnel test also confirmed leaving square edges trailing edges models flying surfaces will increase amount drag best shape trailing edge sharp Thats topic conversation local slopes lately strong support side Due experience Vader planes Dick Vader sands trailing edges paper-thin Ive learned like sharp edges other Glider designers have insisted square trailing edges actually have less drag mention auto motive design squared-off tail ends race cars break airflow suddenly reduce drag According Seligs wind tunnel tests square-edge theory hot setup suppose thatll put end ama teur aerodynamicists arguments Ill bet Ill bet youre right Charlie past few months Ive number discussions about Seligs airfoils thin vs thick trailing edges etc Having heard rumors test sections used Michael chord lengths no smaller 12 wonder about applicability smaller chords Most Slope ships have chords 6- 8-in category therefore considera bly smaller Reynolds numbers Will Selig Donovan data apply dont know Having couple semesters aerody namics am qualified challenge Michaels opinions recently read article written John Barker went great depth about difference tween Eppler 205 S3021 think conclusion just might give something think about think must accept Michael Selig has drawn some very logical conclusions formation has available own enthusi asm tempered little very small varia tions profile shape being talked about tie such things surface roughness building ability As far practical flying results concerned think important forget flavor month factor also fact new model al ways better old oneuntil have flown season Deceptive designs following piece contin ues same line thinking article written Reinhard Lahde appeared newsletter South Bay Soaring Society Silent Flyer Jim good model designer good pi lot latest creation has unusual wing planform something nobody has tried before wins several contests design appears clubs newsletter model magazine copied new planform hailed win ning planformthe Wonderwing trou ble Jims success has absolutely nothing new planform Instead has following 1 Jim good model pilot 2 has well-built model 3 streak good luck other features win ning designs too often lady luck main ingredient success Let us take good unprejudiced look what isnt important standpoint laws nature par ticular aerodynamics 1 Airfoil design selection right airfoil certainly very important among frequently discussed topics litera ture has subject various studies us ing computer programs based boundary layer theory resulting airfoil shapes painfully similar already existing ones example John Barker editor British Bat Chat news letter analyzing new profile Michael Selig expresses surprise small difference tween Selig profile other good profiles wonders about effects unavoidable building inaccuracies surface conditions covering material variances foam/glass wings Regarding allegedly supe nor flying results writes As far prac tical flying results concerned think im portant forget flavor month factor also fact new model al ways better old oneuntil have flown season s second time around statement Presumably merits thinking about MT As far know accurate reliable wind tunnel tests available Reynolds number regime interest therefore opin ion can hardly better stick what has known years example Dr Epplers research contains good solid advice select profiles Slope Racers op posed Thermal fliers plus other rules useful model design problem Dr Ep pIer fails give credit credit due mentioning granddaddy model airfoils Goettingen 549 profile appropriately scaled down thickness thermal flying bit good newer ones very similar often used Ep pIer 205 practically identical Ep pIer 176 drawn same thickness Quabeck family airfoils fishtails permit reduction drag very high coef ficients flaps deflected im portant quick turns Slope Races dont get something nothing however stands reason used Thermal flight sur face drag must slightly higher compared good non-fishtailed profile 2 Wing design wing design must pro vide adequate strength intended purpose Winch launches Slope RacingMT can pro duce forces high 60 lb subjecting wing tremendous bending moments built-up wing spar ribs use carbon fiber spar caps highly recommended 3 Interference drag interface tween fuselage wing fuselage tail surfaces inadequate design can cause considerable drag Unless interface careABELES BIGGEST SCALE PLANSSOCSAENTACSSN SERVICE PP CALE MOREL PLoNSAAAAAi.o5 P AS SAGE CATALOG405N5 32A9 Madison sboo NE 27403 ZIi SCALE OOEAMENTATrOC catalog $100 ff3LUE RIDGE MACHINERY& TOOLS P0 Box 536-Y Hurricane SIN 25526 304-562-3538 offer complete selection lathes mills tools Aviation Modeler 160 Model Aviation ________ STARLITE ST FLIGHT TRAINER 13 WFJG SPAN HAO-tM*ICE GLER EASY TO 6iAO FUN TO PLY t5ucn FLIGHtS COMPLETE QEtAKED S PAGE MANUAL SALSA & HARIYM300 IT $595 odd 45% loal oEdo JAMMASRO P0 Boo I7& AItoWk Sf1 23303 eel 8041 824 0514 pleas act $250 sIipplng doels nqwoo naIled BEETLESuperStcir6O 1987 1989 F3A World Champion Design EC LD4OTh 617W040 hREA 700 SQ IN/SPAN stANOIE 10 cA SPEC IB4G11I 6OIUING AREA 821 SQ 04/SPAN 6S/4NE 10 ae BASIC KIT $150 PREBUILT KIT $395 SPOXY .ASS PJSELAGES TORY SHEETED FOAM WING 8 STAB EPOXY/CARBON sisGRAPHITE FUSELAGE ADJUSTABLE WING MECHANISM WNO aINCLUDED PATTERN TEK iz-I4 -3L Henweemb*au esil far RrB~ fully shaped like interfaces airliners modern sailpianes might actually better separate wing fuselage use pylon mount use carbon fiber makes pos sible very light strong connecting pylon per mitting undisturbed airflow around wing fuselage 4 Wing planform As indicated earlier importance ofwing planform shape often over estimated As long some simple rules ob served exact shape wing planform has very little effect aerodynamic quality Theoret ically elliptical best true ignore effect Reynolds numbers model airplanes elliptical definitely op timum since Reynolds numbers wing tip go zero desirable tapered wing trapezoid wing rec tangular middle section better elliptical tip chord too small fact straight rectangular wing almost good espe cially washout used near wing tips approach elliptical distribution Furthermore lift aerodynamics forgiving actual lift dis tribution will always tend toward elliptical will seek middle ground between planform true ellipse 5 Sweepback Sweepback forward sweep long exaggerated has quite negligible effect wing efficiency case sweptback wing having spars also bent back bending moment transmitted center spars can resolved vectors perpen dicular planes planes oriented vertical aligned isith longitudinal axis aircraft other aligned along lateral axis aircraft mental picture becomes clearer Ed moment vectors spars resolved onto planes becomes evident mo ment vectors cancel out planes Rather resultimg moment left over must taken care structurally forgetting can lead disastrous conse quences slight amount sweepback present spar should arranged straight fashion avoid difficulties 6 Wing tip shape literature too much fuss often made wing tip shape has suggested use some magical tip shape other could significantly affectie minimizethe induced drag entirely correct Induced drag wholly function total lift b wingspan c dynamic pressure Everything else best second- third- order effect Most wing tip shapes seen good models full-size airplanes entirely adequate can hardly improved upon generate additional drag beyond unavoidable induced drag region downdraft separated region undisturbed flow two vortex tubes emanating wing tips develops behind wing reaction lift Since flow sort curls around wing tips makes sense use rounded cross section dont think can better conclusion dont just copy somebodys winning design thinking old triedand-true Clark-Y could magic airfoil next dream machine flavor month elliptical may winning won derwing As old Ronny used say Trust verify What above should teach you dont necessarily need latest design advanced innovations successful whether competition sport flying big gest mistake see fliers making assume contest-winning plane will answer problems constantly upgrading newest design making wholehearted effort learn plane theyre already flying best pilots slope thermal flying F3B other discipline advanced designs best know planes pilots concentrate flying skills can squeeze performance out airplane important part winning combination airfoil planform its pilot Slope Race results past few months three major Slope Races have held Viking F3F Slope Race Hanstholm Denmark Hans Weiss Memorial Slope Race Hughes Hills CA unofficial Slope race years Nats Washington concept international Slope Race Den mark looked like great opportunity some top Slope Racers US go head-tohead best Europe has offer Efforts John Dvorak editor SBSSs Silent Flyer CD Preben Norholm form least couple teams US seemed pay off un fortunately things didnt work out end Eventually seven teams made up 40 individual pilots following countries en tered full teams five competitors Bavaria Denmark England Germany Scotland Switzerland Two additional teams formed race Team Eli England Norwe gian team end winner race Englands Nic Wright flying Electra B3 Nic took first place contest also claimed fastest time event48 sec onds up date F3F racing 10 rounds flown competi tion pilot has flight per round flies alone against clock Ten legs flown 100-meter course total pilots scores becoming score round Average times event ran 50- 60second range top three placing teams Denmark England Norway Derbyshire England may next location F3F International Slope Race au tumn 1990 Special thanks John Dvorak providing results years race Hans Weiss Memorial Slope Race held southern California May 20-21 following report Charlie Morey lets us know turned out 'Daryll Perkins brought new plane Hughes Hill proceeded run away competition annual Hans Weiss Memorial Slope Race Although hed campaigning German-made Mueller Comet won Davenport last month time Daryll flying Mark Allens made-in-the-USA Falcon 880 proved right Slope weapon Perkins aced six consecutive heats winning outright no flyoff first glance Falcon 880 seems un likely contender Slope racing Mark Allen Flite Lite Composites designed ship hightech thermal competition machine has mild polyhedral break wing Allen gave Falcon full-house controls rudder ele vator ailerons flaps mixed electroni cally F3B-style utilized two Michael December 1989 161 Rubber & Eng Power Free Flight Display1 Control Line Electric Power RIC Airplanes new illustrated 32 page tabloid size catalog US & Canada $100 Foreign $300 Penn Valley Hobby Center 837-A W Main St Lanadale PA 19446 THE WIREMASTER er/iIer extra large handle bends 1/8-1/4 coils 5/ 32-3116 music wire Wire aeep eliminated ANTI-KREEP WIRE LOCKIB free catalog has hundreds new items free micro bender offer JCM COMPANY 114 WashIngton Terr. Waukegan IL 60085 10 FT 5-17 PLANS $4200 EPOXY GLASS COWLS PLASTIC NOSE TURRETS $5500 IAIIz 3 CATALOGS $900 THE REST IN ScALE-BaR HOLMAN O BOX 741 MA BAR BONG CA BOOS Seligs amazing airfoils starting 53021 root transitioning 53014 tips Falcon 880 Perkins raced beefed up ballasted appropriately weighed over eight pounds news Mark Allen found interesting since hed designed plane 675-lb maximum weight mind wing glassed sported arrow-shaft hinges other wise Allens original thermaling design Its truly beautiful Glider did look out place sitting ground beside straight-winged Slope Racers air another story Mark Grand modified Super Co manche garnered five wins second place Mark put home court advantage work found both lift speed outdistance Perkins RCM Magazine Soaring columnist Don Edberg placed third point behind Grand flyoff decided fourth fifth places Estancia regulars Tony Martin Jason Perrin tied nine points Tonys one-off fiberglass de sign Jasons Snipe collided flyoff Snipe going down Martins ship taking fourth overall Jerry Bridgeman unanimously voted win ner Pilots Choice trophy losing planes Jerry went through new Slope/Electric design two standard Snipes earn coveted award Special thanks go Contest Director Ray Kuntz organizing event Chuck Al len Chucks Model Shop Hawthorne trophies years Mats included F3F-style Slope Race no ones surprise Daryll Perkins ran away everyone captured first place both classes Ive opportunity watch Daryll fly couple races year its hard see successful Daryll smoothest fliers around Theres noth ing showy spectacular about way flies just very very consistent As dramatic proof take look variety planes Daryll has flown victory recent monthshis Comet Davenport Mats Falcon Hughes Hill Ron Vanns Eliminator Mats 16-oz/sq-ft limit Coming next time will look connec tion between Slope flying F3B Ill discuss ing similarities exist between two dis ciplines planes pilots RC Electrics/Kopski Continued page 57 flight highest total time four-minute segments plus fraction last partial seg ment wins thinking about event would ap proach participant set about study flight duration cruise power levels various planes idea see much en ergy storage could pack plane al locate speed control needed just maintain altitude effect applying own Rule Thumb #1 MA April 1984 page 77 says power cruise ex pressed watts input motor numerically equals weight plane pounds multi plied wing loading oz per sq foot course rule thumb approximation study involved running carefully con trolled experiments three planes First Challenger modified include geared co balt 15 10 l2-Ah SCEs speed control also ran experiments Eurekaa threechannel sport plane direct-drive Astro 25 14 1 2-Ah SCs speed control Finally ran additional experiments Nytique night-flying Amptique derivative has six 12Ah SCRs economy RC car motor pod speed control three widely varying model designs speed control installa tion such frame-rate high-rate con trols could easily swapped field flew tiring cruise-type flights collect data flight flown carefully mea sured charge ampere-minutes empty wherein charge deliberately made below batteries label capacity flights flown throttle control carefully set allow nonclimbing cruise levels power just enough throttle maintain low-altitude ovals around field Flight tests covered nearly two months under variety temperature humidity wind conditions After amassing respectable data array fol lowing conclusions clearly stood out e Rule Thumb #1 definitely does ballpark ex pected flight results just what approximation should dobut high-rate controls actual flight times vary dramatically de pending type speed control used par ticular cruise times much shorter using frame-rate controls Also case mo tor battery much hotter end flight clear heat associated framerate controls result power wasted power available turn prop fly plane long could done using high-rate controls particulars follows Challenger described above predicted cruise time about 25 minutes average time framerate control 185 minutes highrate control 304 minutes Remember no-thermal flying Eureka cruised average 66 95 minutes respectively Rule Thumb #1 prediction 98 minutes limited data short charges Nytique cruised 24 minutes 39 minutes respectively Predicted time 49 minutes As difference results between speed control types thats explainable Ill get next month now clear under conditions described model power sys tems efficient high-rate controls arc used Actually its control thats efficient rather its motor gains efficiency used high-rate controls high motor battery temperature shorter far flight times clearly show honest expected difference didnt expect such large difference Anyway some thoughts Speed controls often advertised evalu ated exclusive regard on-resistance voltage loss full Frankly con trols know use several MOSFETS metal oxide semiconductor field-effect transistors Ed parallel unless some kind basic blunder within given design should have less same small voltage dropthe same good MOSFETS available manufacturers loss really meaning full-on lossdoes story tell apparent above Besides full-on way control used servo-driven switch electronic switch would better choice May suggest youif youre planning speed control purchase intend vary speed motor modeldo strongly con sider results above course would often just cruise around described above Generally speaking youre going use speed control other full-on youre better off high-rate design would expect since nothing ever simple frame-rate types generally smaller lighter lower cost Decisions decisions Im personally familiar speed con trols high-rate ones know include Jomar SC-4 discontinued too bad SC-5 SM equivalents So also Elden Ken EKE 24U Im told RAM Red 06 have 24U use optically coupled Ill soon using Red 06 optically coupled now have obtained data J0162 Model Aviation Almost Ready Fly. Requires few hours asmbf. Includes necessary accessories/hardware. Balsa construction precovered 20-25 Size CHEROKEE 48 wing span Special 0 Size now available $11296 S&H $600 BLBW PO Box 3634 Cerritos CA 90703-3634Th@ itea~@wDealer 213 940-127020 Size 95InquiriecCOD MofleyOrdws 40 Size 95AcceptedChecks Accepted tallow 7 addItional dayst introduce new event Maxi-Flight event designed technologist strategist pilot requires continuous flight task charge pilot required land relaunch after fourth minute of
Edition: Model Aviation - 1989/12
Page Numbers: 54, 55, 160, 161, 162
BANZAI UPDATE couple columns ago pictured talked about Banzai Slope Soarer being kitted Jerry Teo Since time Banzai has undergone number changes now being kitted Banzai Mk II following notable changes original design fuselage has plywoodreinforced /5-in balsa sides wing includes spruce spar durability resistance flex damage kit now features better instruc tions scale drawings According Jerry kit retains high qual ity prefabrication materials its along introductory price will $28 US plus $350 per kit shipping han dling Jerry also mentioned Banzai Enterprises planning bringing out several kits near future following list Slope de signs firm working Combat Aero batic Delta Wing Pattern-like FAt ship BD-5 F-20 semiscale Tigershark both Unlim ited One-Meter Slope Racers Sounds great huh Drop Jerry line let him know kits youd like see first Write him Banzai Enterprises 2997 Anderson Ave Port Alberni British Columbia V9Y 2V3 Cana da Photo mix-up seems captions two photos July column mixed up has little bit confusion cause Please note captions photos Mike Reeds Slopar Banzai Enter prises Banzai inadvertently reversed Apol ogies concerned confused Torrey Pines Scale Fun-Fly would like chance fly Americas best-known slopes some countrys enthusias tic Scale fliers chance Thanksgiving weekend November 24-26 1989 tradi tion National Scale Slope Soaring Fun-Fly held past two years Tn-Cities WA event will three days pure Scale Soaring addition regular flying Charlie Money PR man fun-fly editor Slope Soar jog News scheduling Scale Glider demonstra tions during weekend Various manufacturers will fly planes talk about show off kits well answer questions As Charlie puts demos will entertain ing pilots spectators theyll formative interested kit buyers theyll help struggling garage-shop industry make few sales Sounds like great idea Charlie compiling mailing list interested fliers youd like get little informa tion Torrey Pines Gulls Scale Fun-Fly send name address phone number Charlie Morey Slope Soaring News 2601 E 19th Street #29 Signal Hill CA 90804 Penetrator update During recent phone call John Fotiu JM Glascraft got longawaited news larger version Penetra tor works Being about 50% larger original new version will ideal larger slopes like Eagle Butte Richland WA Coyote Hills northern California cant wait ballast up send Out 30plus lift John also has great-looking Mirage III delta wing Therell future column info Mirage new Pene trator contact John JM Glascraft 30820 May flower Roseville MI 48066 596060a better Eppler 374 Anyone has spent much time slopes has come across Eppler 374 form another Known Slope Soarers airfoil 374 has part sport years recent edition Slope Soaring Newr Charlie Money took look epic airfoil its newly derived cousin Selig-Donovan 6060 Eppler 374 semisymmetnical airfoil Slope Soaring standard Its fast offers Left Although best known being member national F3B team past four years Rich Spicer also avid Sloper Nova designed number years ago still potent Racer Right Designed unbridled speed mind Ken Gregorys Renegade reg ular California Slope Racing circuit Kens leader composite construction all-glass Renegade great example work 54 Model Aviation Radio Control Slope Soaring Mark Triebes 20794 Kreisier Cc Saratoga CA 95070 Torrey Pines No might see Scale ships like gorgeous five-meter LS-1 Tar ray Pines Scale Fun Fly held Thanksgiving weekend Photo Sailpianes International Also located NWSS booth Puyallup Gene Copes Spitfire P55 has grown leaps bounds last year Torrey Pines Scale Fun Fly will show case PSS kits Photo Wil Byers good inverted performance Aerobatics Its popular airfoils use custom Slope Racing ships Its also modified airfoils Dr Epplers stable Almost Sailplane de signer whos played 374 has found way another improve Its thinned tweaked tossed turned tilted inter est making better already Although everyone tinkers 374 attempts limited resources Typ ical approaches trial error seat-of-thepants design eyeball engineering ubiqui tous TLAR Looks About Right Only recent months has someone higher education engineering specif ically low Reynolds number aerodynamic de sign taken 374 wind tunnel analyzed its shortcomings made specific corrections eliminate Perhaps youve heard Michael Seligs air foils Seligs S3021 used Mark Allens Fal con 880 conjunction S3014 tip Mike Reeds Slopar pop ular Again its improved Eppler time popular 205 both casesthe 205 now 374 Selig decreased amount drag produced Eppler airfoils maintaining other wise similar profile June 5-7 1989 Conference Low Reynolds Numbers Aerodynamics took place University Notre Dame confer ence paper called Low Reynolds Number Air foil Design Wind Tunnel Testing Prince ton University presented J F Donovan M S Selig Mr Donovan research scientist McDonnell Douglas Research Laboratories St Louis Mr Selig graduate student Pennsyl vania State University extensive back ground model aircraft airfoil design Michael Selig kind enough provide Slope Soaring News copy paper So dictionary hand six-pack nearby Ive attempted summarize translate technicalese modelers English goes Okay lets start beginning Whats Reynolds number Its means specifying airflow over wing Reynolds numbers stated scientific notationeg 30 x 105—and refer number air molecules flowing across wing Simply put larger number air flows over wing Scientific notation allows us write very Continued page 160 Another First McDaniel RICI New Solid State On-Board Glow-Plug Drivers Now can drive ito 9 glow plugs efficiently automatically new McDaniel On-Board Glow-plug Drivers engine 2 or4 stroke glow has ito 9 cylinders On-Board Glow-Plug Drivor will ease job start ing maintaining idle during taxiing power down flight maneuvers Features Include Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Drive Up 9 Cylinders 48V 500 mAh Batteryt Includes Battery Connector & Wire Jim Rauchs slick F-4 Phantom P55 ship PuVallup Expo Photograph Wil Byers Model 475 Stiewn Optional Battery Pack Jim Magnuson duplicated paint job full-scale P-51 Obsession Word John Fotiu JM Glascrafta larger Penetra tor works Photo Jim Magnuson Another innovation McDaniel RIC kunning Time Increased Larger Battery HANDSOFFCUTII Especially Designed Tapered Wings unique device cutting high quality foam wing cores HANDS OFF cutting both sides lye same time Available hardware package assemble own board Specify 30 40 50 60 ordering Size may changed anytime Man Chord 18 standard Larger chords available Easy assemble Requires 24 Volt Variable Output Power Supply DEALERS WANTED Hands Off Cut II hardware package$87 SO 5 5 H 24 Volt Variable Output power supply 50 5 & H VIDEO FOAM SHOP Foam Shop Part OneCutting Foam Wings sour long cuts made using HANDS OFF CUT IiV H 5Only $2955 includes 5 & H lowei 48 Foam Shop Part TwoCutting Foam Fuselages hour long cuts made using simple bow VHSOnly 52995 includes 5 & H Id ei 48 SUPER BOND ACT ADHESIVE best contact cement have ever used Onip $375 8 oc squeeze bottle Enough 1400 square soC wingAdd $300 S & H lower 48 1/8 inch Phenolic Board Templates 4 X36tos ItOnly $500 * $200S & H NOR-RAY PRODUCTS Sasdbeach Road Wichita Pails Tevas 7831 Tel 8171 6924476 December 1989 55 Just time Christmas TeleHobbies R/C Network Just call 703 709-8554 favorite computer communications software RIC information electronic ordering Sign now avoid rush registration fee NO USAGE CHARGE Help design R/C hobby network want future RC supplies shipped immediately door 800 numbers coming next year RC Slope Soaring/Triebes Continued page 55 large numbers relatively brief manner example 30 x lO5 three times 10 fifth power 300000 As can see its partic ularly useful such small number get up whole number has about 72 zeros after its much easier write 30 x 1072 list 72 zeros time write number Low Reynolds numbers defined Selig-Donovan paper 500000 less wind tunnel tests slow medium fast read ings taken 60000 100000 300000 numbers very low compared associated full-scale powered aircrafthence low Reynolds Number Aero dynamics conference distinguishing characteristic air foil operated low chord Reynolds numbers Re 50 x l0 formation extensive laminar separation bubble either upper lower surfaces both bubble can signifi cantly increase drag quote pretty much sums up entire story SD6060 As air flows over top Eppler 374 breaks away sur face just past high point wing reat taches later back near trailing edge middle beneath layer detached air bub ble turbulent air forms Recognizing bubble source drag Selig set out design new airfoil minimizes drag reshaping 374 slightly Selig de creased size bubble moved ward laminar airflow could reattach wing surface sooner resulted de crease drag improved airfoil performance Does mean SD6060 will replace Eppler 374 new Slope Soaring stan dard performs well hillside did wind tunnel think will Please try let us know about results Let know tooMT Seligs wind tunnel test also confirmed leaving square edges trailing edges models flying surfaces will increase amount drag best shape trailing edge sharp Thats topic conversation local slopes lately strong support side Due experience Vader planes Dick Vader sands trailing edges paper-thin Ive learned like sharp edges other Glider designers have insisted square trailing edges actually have less drag mention auto motive design squared-off tail ends race cars break airflow suddenly reduce drag According Seligs wind tunnel tests square-edge theory hot setup suppose thatll put end ama teur aerodynamicists arguments Ill bet Ill bet youre right Charlie past few months Ive number discussions about Seligs airfoils thin vs thick trailing edges etc Having heard rumors test sections used Michael chord lengths no smaller 12 wonder about applicability smaller chords Most Slope ships have chords 6- 8-in category therefore considera bly smaller Reynolds numbers Will Selig Donovan data apply dont know Having couple semesters aerody namics am qualified challenge Michaels opinions recently read article written John Barker went great depth about difference tween Eppler 205 S3021 think conclusion just might give something think about think must accept Michael Selig has drawn some very logical conclusions formation has available own enthusi asm tempered little very small varia tions profile shape being talked about tie such things surface roughness building ability As far practical flying results concerned think important forget flavor month factor also fact new model al ways better old oneuntil have flown season Deceptive designs following piece contin ues same line thinking article written Reinhard Lahde appeared newsletter South Bay Soaring Society Silent Flyer Jim good model designer good pi lot latest creation has unusual wing planform something nobody has tried before wins several contests design appears clubs newsletter model magazine copied new planform hailed win ning planformthe Wonderwing trou ble Jims success has absolutely nothing new planform Instead has following 1 Jim good model pilot 2 has well-built model 3 streak good luck other features win ning designs too often lady luck main ingredient success Let us take good unprejudiced look what isnt important standpoint laws nature par ticular aerodynamics 1 Airfoil design selection right airfoil certainly very important among frequently discussed topics litera ture has subject various studies us ing computer programs based boundary layer theory resulting airfoil shapes painfully similar already existing ones example John Barker editor British Bat Chat news letter analyzing new profile Michael Selig expresses surprise small difference tween Selig profile other good profiles wonders about effects unavoidable building inaccuracies surface conditions covering material variances foam/glass wings Regarding allegedly supe nor flying results writes As far prac tical flying results concerned think im portant forget flavor month factor also fact new model al ways better old oneuntil have flown season s second time around statement Presumably merits thinking about MT As far know accurate reliable wind tunnel tests available Reynolds number regime interest therefore opin ion can hardly better stick what has known years example Dr Epplers research contains good solid advice select profiles Slope Racers op posed Thermal fliers plus other rules useful model design problem Dr Ep pIer fails give credit credit due mentioning granddaddy model airfoils Goettingen 549 profile appropriately scaled down thickness thermal flying bit good newer ones very similar often used Ep pIer 205 practically identical Ep pIer 176 drawn same thickness Quabeck family airfoils fishtails permit reduction drag very high coef ficients flaps deflected im portant quick turns Slope Races dont get something nothing however stands reason used Thermal flight sur face drag must slightly higher compared good non-fishtailed profile 2 Wing design wing design must pro vide adequate strength intended purpose Winch launches Slope RacingMT can pro duce forces high 60 lb subjecting wing tremendous bending moments built-up wing spar ribs use carbon fiber spar caps highly recommended 3 Interference drag interface tween fuselage wing fuselage tail surfaces inadequate design can cause considerable drag Unless interface careABELES BIGGEST SCALE PLANSSOCSAENTACSSN SERVICE PP CALE MOREL PLoNSAAAAAi.o5 P AS SAGE CATALOG405N5 32A9 Madison sboo NE 27403 ZIi SCALE OOEAMENTATrOC catalog $100 ff3LUE RIDGE MACHINERY& TOOLS P0 Box 536-Y Hurricane SIN 25526 304-562-3538 offer complete selection lathes mills tools Aviation Modeler 160 Model Aviation ________ STARLITE ST FLIGHT TRAINER 13 WFJG SPAN HAO-tM*ICE GLER EASY TO 6iAO FUN TO PLY t5ucn FLIGHtS COMPLETE QEtAKED S PAGE MANUAL SALSA & HARIYM300 IT $595 odd 45% loal oEdo JAMMASRO P0 Boo I7& AItoWk Sf1 23303 eel 8041 824 0514 pleas act $250 sIipplng doels nqwoo naIled BEETLESuperStcir6O 1987 1989 F3A World Champion Design EC LD4OTh 617W040 hREA 700 SQ IN/SPAN stANOIE 10 cA SPEC IB4G11I 6OIUING AREA 821 SQ 04/SPAN 6S/4NE 10 ae BASIC KIT $150 PREBUILT KIT $395 SPOXY .ASS PJSELAGES TORY SHEETED FOAM WING 8 STAB EPOXY/CARBON sisGRAPHITE FUSELAGE ADJUSTABLE WING MECHANISM WNO aINCLUDED PATTERN TEK iz-I4 -3L Henweemb*au esil far RrB~ fully shaped like interfaces airliners modern sailpianes might actually better separate wing fuselage use pylon mount use carbon fiber makes pos sible very light strong connecting pylon per mitting undisturbed airflow around wing fuselage 4 Wing planform As indicated earlier importance ofwing planform shape often over estimated As long some simple rules ob served exact shape wing planform has very little effect aerodynamic quality Theoret ically elliptical best true ignore effect Reynolds numbers model airplanes elliptical definitely op timum since Reynolds numbers wing tip go zero desirable tapered wing trapezoid wing rec tangular middle section better elliptical tip chord too small fact straight rectangular wing almost good espe cially washout used near wing tips approach elliptical distribution Furthermore lift aerodynamics forgiving actual lift dis tribution will always tend toward elliptical will seek middle ground between planform true ellipse 5 Sweepback Sweepback forward sweep long exaggerated has quite negligible effect wing efficiency case sweptback wing having spars also bent back bending moment transmitted center spars can resolved vectors perpen dicular planes planes oriented vertical aligned isith longitudinal axis aircraft other aligned along lateral axis aircraft mental picture becomes clearer Ed moment vectors spars resolved onto planes becomes evident mo ment vectors cancel out planes Rather resultimg moment left over must taken care structurally forgetting can lead disastrous conse quences slight amount sweepback present spar should arranged straight fashion avoid difficulties 6 Wing tip shape literature too much fuss often made wing tip shape has suggested use some magical tip shape other could significantly affectie minimizethe induced drag entirely correct Induced drag wholly function total lift b wingspan c dynamic pressure Everything else best second- third- order effect Most wing tip shapes seen good models full-size airplanes entirely adequate can hardly improved upon generate additional drag beyond unavoidable induced drag region downdraft separated region undisturbed flow two vortex tubes emanating wing tips develops behind wing reaction lift Since flow sort curls around wing tips makes sense use rounded cross section dont think can better conclusion dont just copy somebodys winning design thinking old triedand-true Clark-Y could magic airfoil next dream machine flavor month elliptical may winning won derwing As old Ronny used say Trust verify What above should teach you dont necessarily need latest design advanced innovations successful whether competition sport flying big gest mistake see fliers making assume contest-winning plane will answer problems constantly upgrading newest design making wholehearted effort learn plane theyre already flying best pilots slope thermal flying F3B other discipline advanced designs best know planes pilots concentrate flying skills can squeeze performance out airplane important part winning combination airfoil planform its pilot Slope Race results past few months three major Slope Races have held Viking F3F Slope Race Hanstholm Denmark Hans Weiss Memorial Slope Race Hughes Hills CA unofficial Slope race years Nats Washington concept international Slope Race Den mark looked like great opportunity some top Slope Racers US go head-tohead best Europe has offer Efforts John Dvorak editor SBSSs Silent Flyer CD Preben Norholm form least couple teams US seemed pay off un fortunately things didnt work out end Eventually seven teams made up 40 individual pilots following countries en tered full teams five competitors Bavaria Denmark England Germany Scotland Switzerland Two additional teams formed race Team Eli England Norwe gian team end winner race Englands Nic Wright flying Electra B3 Nic took first place contest also claimed fastest time event48 sec onds up date F3F racing 10 rounds flown competi tion pilot has flight per round flies alone against clock Ten legs flown 100-meter course total pilots scores becoming score round Average times event ran 50- 60second range top three placing teams Denmark England Norway Derbyshire England may next location F3F International Slope Race au tumn 1990 Special thanks John Dvorak providing results years race Hans Weiss Memorial Slope Race held southern California May 20-21 following report Charlie Morey lets us know turned out 'Daryll Perkins brought new plane Hughes Hill proceeded run away competition annual Hans Weiss Memorial Slope Race Although hed campaigning German-made Mueller Comet won Davenport last month time Daryll flying Mark Allens made-in-the-USA Falcon 880 proved right Slope weapon Perkins aced six consecutive heats winning outright no flyoff first glance Falcon 880 seems un likely contender Slope racing Mark Allen Flite Lite Composites designed ship hightech thermal competition machine has mild polyhedral break wing Allen gave Falcon full-house controls rudder ele vator ailerons flaps mixed electroni cally F3B-style utilized two Michael December 1989 161 Rubber & Eng Power Free Flight Display1 Control Line Electric Power RIC Airplanes new illustrated 32 page tabloid size catalog US & Canada $100 Foreign $300 Penn Valley Hobby Center 837-A W Main St Lanadale PA 19446 THE WIREMASTER er/iIer extra large handle bends 1/8-1/4 coils 5/ 32-3116 music wire Wire aeep eliminated ANTI-KREEP WIRE LOCKIB free catalog has hundreds new items free micro bender offer JCM COMPANY 114 WashIngton Terr. Waukegan IL 60085 10 FT 5-17 PLANS $4200 EPOXY GLASS COWLS PLASTIC NOSE TURRETS $5500 IAIIz 3 CATALOGS $900 THE REST IN ScALE-BaR HOLMAN O BOX 741 MA BAR BONG CA BOOS Seligs amazing airfoils starting 53021 root transitioning 53014 tips Falcon 880 Perkins raced beefed up ballasted appropriately weighed over eight pounds news Mark Allen found interesting since hed designed plane 675-lb maximum weight mind wing glassed sported arrow-shaft hinges other wise Allens original thermaling design Its truly beautiful Glider did look out place sitting ground beside straight-winged Slope Racers air another story Mark Grand modified Super Co manche garnered five wins second place Mark put home court advantage work found both lift speed outdistance Perkins RCM Magazine Soaring columnist Don Edberg placed third point behind Grand flyoff decided fourth fifth places Estancia regulars Tony Martin Jason Perrin tied nine points Tonys one-off fiberglass de sign Jasons Snipe collided flyoff Snipe going down Martins ship taking fourth overall Jerry Bridgeman unanimously voted win ner Pilots Choice trophy losing planes Jerry went through new Slope/Electric design two standard Snipes earn coveted award Special thanks go Contest Director Ray Kuntz organizing event Chuck Al len Chucks Model Shop Hawthorne trophies years Mats included F3F-style Slope Race no ones surprise Daryll Perkins ran away everyone captured first place both classes Ive opportunity watch Daryll fly couple races year its hard see successful Daryll smoothest fliers around Theres noth ing showy spectacular about way flies just very very consistent As dramatic proof take look variety planes Daryll has flown victory recent monthshis Comet Davenport Mats Falcon Hughes Hill Ron Vanns Eliminator Mats 16-oz/sq-ft limit Coming next time will look connec tion between Slope flying F3B Ill discuss ing similarities exist between two dis ciplines planes pilots RC Electrics/Kopski Continued page 57 flight highest total time four-minute segments plus fraction last partial seg ment wins thinking about event would ap proach participant set about study flight duration cruise power levels various planes idea see much en ergy storage could pack plane al locate speed control needed just maintain altitude effect applying own Rule Thumb #1 MA April 1984 page 77 says power cruise ex pressed watts input motor numerically equals weight plane pounds multi plied wing loading oz per sq foot course rule thumb approximation study involved running carefully con trolled experiments three planes First Challenger modified include geared co balt 15 10 l2-Ah SCEs speed control also ran experiments Eurekaa threechannel sport plane direct-drive Astro 25 14 1 2-Ah SCs speed control Finally ran additional experiments Nytique night-flying Amptique derivative has six 12Ah SCRs economy RC car motor pod speed control three widely varying model designs speed control installa tion such frame-rate high-rate con trols could easily swapped field flew tiring cruise-type flights collect data flight flown carefully mea sured charge ampere-minutes empty wherein charge deliberately made below batteries label capacity flights flown throttle control carefully set allow nonclimbing cruise levels power just enough throttle maintain low-altitude ovals around field Flight tests covered nearly two months under variety temperature humidity wind conditions After amassing respectable data array fol lowing conclusions clearly stood out e Rule Thumb #1 definitely does ballpark ex pected flight results just what approximation should dobut high-rate controls actual flight times vary dramatically de pending type speed control used par ticular cruise times much shorter using frame-rate controls Also case mo tor battery much hotter end flight clear heat associated framerate controls result power wasted power available turn prop fly plane long could done using high-rate controls particulars follows Challenger described above predicted cruise time about 25 minutes average time framerate control 185 minutes highrate control 304 minutes Remember no-thermal flying Eureka cruised average 66 95 minutes respectively Rule Thumb #1 prediction 98 minutes limited data short charges Nytique cruised 24 minutes 39 minutes respectively Predicted time 49 minutes As difference results between speed control types thats explainable Ill get next month now clear under conditions described model power sys tems efficient high-rate controls arc used Actually its control thats efficient rather its motor gains efficiency used high-rate controls high motor battery temperature shorter far flight times clearly show honest expected difference didnt expect such large difference Anyway some thoughts Speed controls often advertised evalu ated exclusive regard on-resistance voltage loss full Frankly con trols know use several MOSFETS metal oxide semiconductor field-effect transistors Ed parallel unless some kind basic blunder within given design should have less same small voltage dropthe same good MOSFETS available manufacturers loss really meaning full-on lossdoes story tell apparent above Besides full-on way control used servo-driven switch electronic switch would better choice May suggest youif youre planning speed control purchase intend vary speed motor modeldo strongly con sider results above course would often just cruise around described above Generally speaking youre going use speed control other full-on youre better off high-rate design would expect since nothing ever simple frame-rate types generally smaller lighter lower cost Decisions decisions Im personally familiar speed con trols high-rate ones know include Jomar SC-4 discontinued too bad SC-5 SM equivalents So also Elden Ken EKE 24U Im told RAM Red 06 have 24U use optically coupled Ill soon using Red 06 optically coupled now have obtained data J0162 Model Aviation Almost Ready Fly. Requires few hours asmbf. Includes necessary accessories/hardware. Balsa construction precovered 20-25 Size CHEROKEE 48 wing span Special 0 Size now available $11296 S&H $600 BLBW PO Box 3634 Cerritos CA 90703-3634Th@ itea~@wDealer 213 940-127020 Size 95InquiriecCOD MofleyOrdws 40 Size 95AcceptedChecks Accepted tallow 7 addItional dayst introduce new event Maxi-Flight event designed technologist strategist pilot requires continuous flight task charge pilot required land relaunch after fourth minute of
Edition: Model Aviation - 1989/12
Page Numbers: 54, 55, 160, 161, 162
BANZAI UPDATE couple columns ago pictured talked about Banzai Slope Soarer being kitted Jerry Teo Since time Banzai has undergone number changes now being kitted Banzai Mk II following notable changes original design fuselage has plywoodreinforced /5-in balsa sides wing includes spruce spar durability resistance flex damage kit now features better instruc tions scale drawings According Jerry kit retains high qual ity prefabrication materials its along introductory price will $28 US plus $350 per kit shipping han dling Jerry also mentioned Banzai Enterprises planning bringing out several kits near future following list Slope de signs firm working Combat Aero batic Delta Wing Pattern-like FAt ship BD-5 F-20 semiscale Tigershark both Unlim ited One-Meter Slope Racers Sounds great huh Drop Jerry line let him know kits youd like see first Write him Banzai Enterprises 2997 Anderson Ave Port Alberni British Columbia V9Y 2V3 Cana da Photo mix-up seems captions two photos July column mixed up has little bit confusion cause Please note captions photos Mike Reeds Slopar Banzai Enter prises Banzai inadvertently reversed Apol ogies concerned confused Torrey Pines Scale Fun-Fly would like chance fly Americas best-known slopes some countrys enthusias tic Scale fliers chance Thanksgiving weekend November 24-26 1989 tradi tion National Scale Slope Soaring Fun-Fly held past two years Tn-Cities WA event will three days pure Scale Soaring addition regular flying Charlie Money PR man fun-fly editor Slope Soar jog News scheduling Scale Glider demonstra tions during weekend Various manufacturers will fly planes talk about show off kits well answer questions As Charlie puts demos will entertain ing pilots spectators theyll formative interested kit buyers theyll help struggling garage-shop industry make few sales Sounds like great idea Charlie compiling mailing list interested fliers youd like get little informa tion Torrey Pines Gulls Scale Fun-Fly send name address phone number Charlie Morey Slope Soaring News 2601 E 19th Street #29 Signal Hill CA 90804 Penetrator update During recent phone call John Fotiu JM Glascraft got longawaited news larger version Penetra tor works Being about 50% larger original new version will ideal larger slopes like Eagle Butte Richland WA Coyote Hills northern California cant wait ballast up send Out 30plus lift John also has great-looking Mirage III delta wing Therell future column info Mirage new Pene trator contact John JM Glascraft 30820 May flower Roseville MI 48066 596060a better Eppler 374 Anyone has spent much time slopes has come across Eppler 374 form another Known Slope Soarers airfoil 374 has part sport years recent edition Slope Soaring Newr Charlie Money took look epic airfoil its newly derived cousin Selig-Donovan 6060 Eppler 374 semisymmetnical airfoil Slope Soaring standard Its fast offers Left Although best known being member national F3B team past four years Rich Spicer also avid Sloper Nova designed number years ago still potent Racer Right Designed unbridled speed mind Ken Gregorys Renegade reg ular California Slope Racing circuit Kens leader composite construction all-glass Renegade great example work 54 Model Aviation Radio Control Slope Soaring Mark Triebes 20794 Kreisier Cc Saratoga CA 95070 Torrey Pines No might see Scale ships like gorgeous five-meter LS-1 Tar ray Pines Scale Fun Fly held Thanksgiving weekend Photo Sailpianes International Also located NWSS booth Puyallup Gene Copes Spitfire P55 has grown leaps bounds last year Torrey Pines Scale Fun Fly will show case PSS kits Photo Wil Byers good inverted performance Aerobatics Its popular airfoils use custom Slope Racing ships Its also modified airfoils Dr Epplers stable Almost Sailplane de signer whos played 374 has found way another improve Its thinned tweaked tossed turned tilted inter est making better already Although everyone tinkers 374 attempts limited resources Typ ical approaches trial error seat-of-thepants design eyeball engineering ubiqui tous TLAR Looks About Right Only recent months has someone higher education engineering specif ically low Reynolds number aerodynamic de sign taken 374 wind tunnel analyzed its shortcomings made specific corrections eliminate Perhaps youve heard Michael Seligs air foils Seligs S3021 used Mark Allens Fal con 880 conjunction S3014 tip Mike Reeds Slopar pop ular Again its improved Eppler time popular 205 both casesthe 205 now 374 Selig decreased amount drag produced Eppler airfoils maintaining other wise similar profile June 5-7 1989 Conference Low Reynolds Numbers Aerodynamics took place University Notre Dame confer ence paper called Low Reynolds Number Air foil Design Wind Tunnel Testing Prince ton University presented J F Donovan M S Selig Mr Donovan research scientist McDonnell Douglas Research Laboratories St Louis Mr Selig graduate student Pennsyl vania State University extensive back ground model aircraft airfoil design Michael Selig kind enough provide Slope Soaring News copy paper So dictionary hand six-pack nearby Ive attempted summarize translate technicalese modelers English goes Okay lets start beginning Whats Reynolds number Its means specifying airflow over wing Reynolds numbers stated scientific notationeg 30 x 105—and refer number air molecules flowing across wing Simply put larger number air flows over wing Scientific notation allows us write very Continued page 160 Another First McDaniel RICI New Solid State On-Board Glow-Plug Drivers Now can drive ito 9 glow plugs efficiently automatically new McDaniel On-Board Glow-plug Drivers engine 2 or4 stroke glow has ito 9 cylinders On-Board Glow-Plug Drivor will ease job start ing maintaining idle during taxiing power down flight maneuvers Features Include Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Drive Up 9 Cylinders 48V 500 mAh Batteryt Includes Battery Connector & Wire Jim Rauchs slick F-4 Phantom P55 ship PuVallup Expo Photograph Wil Byers Model 475 Stiewn Optional Battery Pack Jim Magnuson duplicated paint job full-scale P-51 Obsession Word John Fotiu JM Glascrafta larger Penetra tor works Photo Jim Magnuson Another innovation McDaniel RIC kunning Time Increased Larger Battery HANDSOFFCUTII Especially Designed Tapered Wings unique device cutting high quality foam wing cores HANDS OFF cutting both sides lye same time Available hardware package assemble own board Specify 30 40 50 60 ordering Size may changed anytime Man Chord 18 standard Larger chords available Easy assemble Requires 24 Volt Variable Output Power Supply DEALERS WANTED Hands Off Cut II hardware package$87 SO 5 5 H 24 Volt Variable Output power supply 50 5 & H VIDEO FOAM SHOP Foam Shop Part OneCutting Foam Wings sour long cuts made using HANDS OFF CUT IiV H 5Only $2955 includes 5 & H lowei 48 Foam Shop Part TwoCutting Foam Fuselages hour long cuts made using simple bow VHSOnly 52995 includes 5 & H Id ei 48 SUPER BOND ACT ADHESIVE best contact cement have ever used Onip $375 8 oc squeeze bottle Enough 1400 square soC wingAdd $300 S & H lower 48 1/8 inch Phenolic Board Templates 4 X36tos ItOnly $500 * $200S & H NOR-RAY PRODUCTS Sasdbeach Road Wichita Pails Tevas 7831 Tel 8171 6924476 December 1989 55 Just time Christmas TeleHobbies R/C Network Just call 703 709-8554 favorite computer communications software RIC information electronic ordering Sign now avoid rush registration fee NO USAGE CHARGE Help design R/C hobby network want future RC supplies shipped immediately door 800 numbers coming next year RC Slope Soaring/Triebes Continued page 55 large numbers relatively brief manner example 30 x lO5 three times 10 fifth power 300000 As can see its partic ularly useful such small number get up whole number has about 72 zeros after its much easier write 30 x 1072 list 72 zeros time write number Low Reynolds numbers defined Selig-Donovan paper 500000 less wind tunnel tests slow medium fast read ings taken 60000 100000 300000 numbers very low compared associated full-scale powered aircrafthence low Reynolds Number Aero dynamics conference distinguishing characteristic air foil operated low chord Reynolds numbers Re 50 x l0 formation extensive laminar separation bubble either upper lower surfaces both bubble can signifi cantly increase drag quote pretty much sums up entire story SD6060 As air flows over top Eppler 374 breaks away sur face just past high point wing reat taches later back near trailing edge middle beneath layer detached air bub ble turbulent air forms Recognizing bubble source drag Selig set out design new airfoil minimizes drag reshaping 374 slightly Selig de creased size bubble moved ward laminar airflow could reattach wing surface sooner resulted de crease drag improved airfoil performance Does mean SD6060 will replace Eppler 374 new Slope Soaring stan dard performs well hillside did wind tunnel think will Please try let us know about results Let know tooMT Seligs wind tunnel test also confirmed leaving square edges trailing edges models flying surfaces will increase amount drag best shape trailing edge sharp Thats topic conversation local slopes lately strong support side Due experience Vader planes Dick Vader sands trailing edges paper-thin Ive learned like sharp edges other Glider designers have insisted square trailing edges actually have less drag mention auto motive design squared-off tail ends race cars break airflow suddenly reduce drag According Seligs wind tunnel tests square-edge theory hot setup suppose thatll put end ama teur aerodynamicists arguments Ill bet Ill bet youre right Charlie past few months Ive number discussions about Seligs airfoils thin vs thick trailing edges etc Having heard rumors test sections used Michael chord lengths no smaller 12 wonder about applicability smaller chords Most Slope ships have chords 6- 8-in category therefore considera bly smaller Reynolds numbers Will Selig Donovan data apply dont know Having couple semesters aerody namics am qualified challenge Michaels opinions recently read article written John Barker went great depth about difference tween Eppler 205 S3021 think conclusion just might give something think about think must accept Michael Selig has drawn some very logical conclusions formation has available own enthusi asm tempered little very small varia tions profile shape being talked about tie such things surface roughness building ability As far practical flying results concerned think important forget flavor month factor also fact new model al ways better old oneuntil have flown season Deceptive designs following piece contin ues same line thinking article written Reinhard Lahde appeared newsletter South Bay Soaring Society Silent Flyer Jim good model designer good pi lot latest creation has unusual wing planform something nobody has tried before wins several contests design appears clubs newsletter model magazine copied new planform hailed win ning planformthe Wonderwing trou ble Jims success has absolutely nothing new planform Instead has following 1 Jim good model pilot 2 has well-built model 3 streak good luck other features win ning designs too often lady luck main ingredient success Let us take good unprejudiced look what isnt important standpoint laws nature par ticular aerodynamics 1 Airfoil design selection right airfoil certainly very important among frequently discussed topics litera ture has subject various studies us ing computer programs based boundary layer theory resulting airfoil shapes painfully similar already existing ones example John Barker editor British Bat Chat news letter analyzing new profile Michael Selig expresses surprise small difference tween Selig profile other good profiles wonders about effects unavoidable building inaccuracies surface conditions covering material variances foam/glass wings Regarding allegedly supe nor flying results writes As far prac tical flying results concerned think im portant forget flavor month factor also fact new model al ways better old oneuntil have flown season s second time around statement Presumably merits thinking about MT As far know accurate reliable wind tunnel tests available Reynolds number regime interest therefore opin ion can hardly better stick what has known years example Dr Epplers research contains good solid advice select profiles Slope Racers op posed Thermal fliers plus other rules useful model design problem Dr Ep pIer fails give credit credit due mentioning granddaddy model airfoils Goettingen 549 profile appropriately scaled down thickness thermal flying bit good newer ones very similar often used Ep pIer 205 practically identical Ep pIer 176 drawn same thickness Quabeck family airfoils fishtails permit reduction drag very high coef ficients flaps deflected im portant quick turns Slope Races dont get something nothing however stands reason used Thermal flight sur face drag must slightly higher compared good non-fishtailed profile 2 Wing design wing design must pro vide adequate strength intended purpose Winch launches Slope RacingMT can pro duce forces high 60 lb subjecting wing tremendous bending moments built-up wing spar ribs use carbon fiber spar caps highly recommended 3 Interference drag interface tween fuselage wing fuselage tail surfaces inadequate design can cause considerable drag Unless interface careABELES BIGGEST SCALE PLANSSOCSAENTACSSN SERVICE PP CALE MOREL PLoNSAAAAAi.o5 P AS SAGE CATALOG405N5 32A9 Madison sboo NE 27403 ZIi SCALE OOEAMENTATrOC catalog $100 ff3LUE RIDGE MACHINERY& TOOLS P0 Box 536-Y Hurricane SIN 25526 304-562-3538 offer complete selection lathes mills tools Aviation Modeler 160 Model Aviation ________ STARLITE ST FLIGHT TRAINER 13 WFJG SPAN HAO-tM*ICE GLER EASY TO 6iAO FUN TO PLY t5ucn FLIGHtS COMPLETE QEtAKED S PAGE MANUAL SALSA & HARIYM300 IT $595 odd 45% loal oEdo JAMMASRO P0 Boo I7& AItoWk Sf1 23303 eel 8041 824 0514 pleas act $250 sIipplng doels nqwoo naIled BEETLESuperStcir6O 1987 1989 F3A World Champion Design EC LD4OTh 617W040 hREA 700 SQ IN/SPAN stANOIE 10 cA SPEC IB4G11I 6OIUING AREA 821 SQ 04/SPAN 6S/4NE 10 ae BASIC KIT $150 PREBUILT KIT $395 SPOXY .ASS PJSELAGES TORY SHEETED FOAM WING 8 STAB EPOXY/CARBON sisGRAPHITE FUSELAGE ADJUSTABLE WING MECHANISM WNO aINCLUDED PATTERN TEK iz-I4 -3L Henweemb*au esil far RrB~ fully shaped like interfaces airliners modern sailpianes might actually better separate wing fuselage use pylon mount use carbon fiber makes pos sible very light strong connecting pylon per mitting undisturbed airflow around wing fuselage 4 Wing planform As indicated earlier importance ofwing planform shape often over estimated As long some simple rules ob served exact shape wing planform has very little effect aerodynamic quality Theoret ically elliptical best true ignore effect Reynolds numbers model airplanes elliptical definitely op timum since Reynolds numbers wing tip go zero desirable tapered wing trapezoid wing rec tangular middle section better elliptical tip chord too small fact straight rectangular wing almost good espe cially washout used near wing tips approach elliptical distribution Furthermore lift aerodynamics forgiving actual lift dis tribution will always tend toward elliptical will seek middle ground between planform true ellipse 5 Sweepback Sweepback forward sweep long exaggerated has quite negligible effect wing efficiency case sweptback wing having spars also bent back bending moment transmitted center spars can resolved vectors perpen dicular planes planes oriented vertical aligned isith longitudinal axis aircraft other aligned along lateral axis aircraft mental picture becomes clearer Ed moment vectors spars resolved onto planes becomes evident mo ment vectors cancel out planes Rather resultimg moment left over must taken care structurally forgetting can lead disastrous conse quences slight amount sweepback present spar should arranged straight fashion avoid difficulties 6 Wing tip shape literature too much fuss often made wing tip shape has suggested use some magical tip shape other could significantly affectie minimizethe induced drag entirely correct Induced drag wholly function total lift b wingspan c dynamic pressure Everything else best second- third- order effect Most wing tip shapes seen good models full-size airplanes entirely adequate can hardly improved upon generate additional drag beyond unavoidable induced drag region downdraft separated region undisturbed flow two vortex tubes emanating wing tips develops behind wing reaction lift Since flow sort curls around wing tips makes sense use rounded cross section dont think can better conclusion dont just copy somebodys winning design thinking old triedand-true Clark-Y could magic airfoil next dream machine flavor month elliptical may winning won derwing As old Ronny used say Trust verify What above should teach you dont necessarily need latest design advanced innovations successful whether competition sport flying big gest mistake see fliers making assume contest-winning plane will answer problems constantly upgrading newest design making wholehearted effort learn plane theyre already flying best pilots slope thermal flying F3B other discipline advanced designs best know planes pilots concentrate flying skills can squeeze performance out airplane important part winning combination airfoil planform its pilot Slope Race results past few months three major Slope Races have held Viking F3F Slope Race Hanstholm Denmark Hans Weiss Memorial Slope Race Hughes Hills CA unofficial Slope race years Nats Washington concept international Slope Race Den mark looked like great opportunity some top Slope Racers US go head-tohead best Europe has offer Efforts John Dvorak editor SBSSs Silent Flyer CD Preben Norholm form least couple teams US seemed pay off un fortunately things didnt work out end Eventually seven teams made up 40 individual pilots following countries en tered full teams five competitors Bavaria Denmark England Germany Scotland Switzerland Two additional teams formed race Team Eli England Norwe gian team end winner race Englands Nic Wright flying Electra B3 Nic took first place contest also claimed fastest time event48 sec onds up date F3F racing 10 rounds flown competi tion pilot has flight per round flies alone against clock Ten legs flown 100-meter course total pilots scores becoming score round Average times event ran 50- 60second range top three placing teams Denmark England Norway Derbyshire England may next location F3F International Slope Race au tumn 1990 Special thanks John Dvorak providing results years race Hans Weiss Memorial Slope Race held southern California May 20-21 following report Charlie Morey lets us know turned out 'Daryll Perkins brought new plane Hughes Hill proceeded run away competition annual Hans Weiss Memorial Slope Race Although hed campaigning German-made Mueller Comet won Davenport last month time Daryll flying Mark Allens made-in-the-USA Falcon 880 proved right Slope weapon Perkins aced six consecutive heats winning outright no flyoff first glance Falcon 880 seems un likely contender Slope racing Mark Allen Flite Lite Composites designed ship hightech thermal competition machine has mild polyhedral break wing Allen gave Falcon full-house controls rudder ele vator ailerons flaps mixed electroni cally F3B-style utilized two Michael December 1989 161 Rubber & Eng Power Free Flight Display1 Control Line Electric Power RIC Airplanes new illustrated 32 page tabloid size catalog US & Canada $100 Foreign $300 Penn Valley Hobby Center 837-A W Main St Lanadale PA 19446 THE WIREMASTER er/iIer extra large handle bends 1/8-1/4 coils 5/ 32-3116 music wire Wire aeep eliminated ANTI-KREEP WIRE LOCKIB free catalog has hundreds new items free micro bender offer JCM COMPANY 114 WashIngton Terr. Waukegan IL 60085 10 FT 5-17 PLANS $4200 EPOXY GLASS COWLS PLASTIC NOSE TURRETS $5500 IAIIz 3 CATALOGS $900 THE REST IN ScALE-BaR HOLMAN O BOX 741 MA BAR BONG CA BOOS Seligs amazing airfoils starting 53021 root transitioning 53014 tips Falcon 880 Perkins raced beefed up ballasted appropriately weighed over eight pounds news Mark Allen found interesting since hed designed plane 675-lb maximum weight mind wing glassed sported arrow-shaft hinges other wise Allens original thermaling design Its truly beautiful Glider did look out place sitting ground beside straight-winged Slope Racers air another story Mark Grand modified Super Co manche garnered five wins second place Mark put home court advantage work found both lift speed outdistance Perkins RCM Magazine Soaring columnist Don Edberg placed third point behind Grand flyoff decided fourth fifth places Estancia regulars Tony Martin Jason Perrin tied nine points Tonys one-off fiberglass de sign Jasons Snipe collided flyoff Snipe going down Martins ship taking fourth overall Jerry Bridgeman unanimously voted win ner Pilots Choice trophy losing planes Jerry went through new Slope/Electric design two standard Snipes earn coveted award Special thanks go Contest Director Ray Kuntz organizing event Chuck Al len Chucks Model Shop Hawthorne trophies years Mats included F3F-style Slope Race no ones surprise Daryll Perkins ran away everyone captured first place both classes Ive opportunity watch Daryll fly couple races year its hard see successful Daryll smoothest fliers around Theres noth ing showy spectacular about way flies just very very consistent As dramatic proof take look variety planes Daryll has flown victory recent monthshis Comet Davenport Mats Falcon Hughes Hill Ron Vanns Eliminator Mats 16-oz/sq-ft limit Coming next time will look connec tion between Slope flying F3B Ill discuss ing similarities exist between two dis ciplines planes pilots RC Electrics/Kopski Continued page 57 flight highest total time four-minute segments plus fraction last partial seg ment wins thinking about event would ap proach participant set about study flight duration cruise power levels various planes idea see much en ergy storage could pack plane al locate speed control needed just maintain altitude effect applying own Rule Thumb #1 MA April 1984 page 77 says power cruise ex pressed watts input motor numerically equals weight plane pounds multi plied wing loading oz per sq foot course rule thumb approximation study involved running carefully con trolled experiments three planes First Challenger modified include geared co balt 15 10 l2-Ah SCEs speed control also ran experiments Eurekaa threechannel sport plane direct-drive Astro 25 14 1 2-Ah SCs speed control Finally ran additional experiments Nytique night-flying Amptique derivative has six 12Ah SCRs economy RC car motor pod speed control three widely varying model designs speed control installa tion such frame-rate high-rate con trols could easily swapped field flew tiring cruise-type flights collect data flight flown carefully mea sured charge ampere-minutes empty wherein charge deliberately made below batteries label capacity flights flown throttle control carefully set allow nonclimbing cruise levels power just enough throttle maintain low-altitude ovals around field Flight tests covered nearly two months under variety temperature humidity wind conditions After amassing respectable data array fol lowing conclusions clearly stood out e Rule Thumb #1 definitely does ballpark ex pected flight results just what approximation should dobut high-rate controls actual flight times vary dramatically de pending type speed control used par ticular cruise times much shorter using frame-rate controls Also case mo tor battery much hotter end flight clear heat associated framerate controls result power wasted power available turn prop fly plane long could done using high-rate controls particulars follows Challenger described above predicted cruise time about 25 minutes average time framerate control 185 minutes highrate control 304 minutes Remember no-thermal flying Eureka cruised average 66 95 minutes respectively Rule Thumb #1 prediction 98 minutes limited data short charges Nytique cruised 24 minutes 39 minutes respectively Predicted time 49 minutes As difference results between speed control types thats explainable Ill get next month now clear under conditions described model power sys tems efficient high-rate controls arc used Actually its control thats efficient rather its motor gains efficiency used high-rate controls high motor battery temperature shorter far flight times clearly show honest expected difference didnt expect such large difference Anyway some thoughts Speed controls often advertised evalu ated exclusive regard on-resistance voltage loss full Frankly con trols know use several MOSFETS metal oxide semiconductor field-effect transistors Ed parallel unless some kind basic blunder within given design should have less same small voltage dropthe same good MOSFETS available manufacturers loss really meaning full-on lossdoes story tell apparent above Besides full-on way control used servo-driven switch electronic switch would better choice May suggest youif youre planning speed control purchase intend vary speed motor modeldo strongly con sider results above course would often just cruise around described above Generally speaking youre going use speed control other full-on youre better off high-rate design would expect since nothing ever simple frame-rate types generally smaller lighter lower cost Decisions decisions Im personally familiar speed con trols high-rate ones know include Jomar SC-4 discontinued too bad SC-5 SM equivalents So also Elden Ken EKE 24U Im told RAM Red 06 have 24U use optically coupled Ill soon using Red 06 optically coupled now have obtained data J0162 Model Aviation Almost Ready Fly. Requires few hours asmbf. Includes necessary accessories/hardware. Balsa construction precovered 20-25 Size CHEROKEE 48 wing span Special 0 Size now available $11296 S&H $600 BLBW PO Box 3634 Cerritos CA 90703-3634Th@ itea~@wDealer 213 940-127020 Size 95InquiriecCOD MofleyOrdws 40 Size 95AcceptedChecks Accepted tallow 7 addItional dayst introduce new event Maxi-Flight event designed technologist strategist pilot requires continuous flight task charge pilot required land relaunch after fourth minute of
Edition: Model Aviation - 1989/12
Page Numbers: 54, 55, 160, 161, 162
BANZAI UPDATE couple columns ago pictured talked about Banzai Slope Soarer being kitted Jerry Teo Since time Banzai has undergone number changes now being kitted Banzai Mk II following notable changes original design fuselage has plywoodreinforced /5-in balsa sides wing includes spruce spar durability resistance flex damage kit now features better instruc tions scale drawings According Jerry kit retains high qual ity prefabrication materials its along introductory price will $28 US plus $350 per kit shipping han dling Jerry also mentioned Banzai Enterprises planning bringing out several kits near future following list Slope de signs firm working Combat Aero batic Delta Wing Pattern-like FAt ship BD-5 F-20 semiscale Tigershark both Unlim ited One-Meter Slope Racers Sounds great huh Drop Jerry line let him know kits youd like see first Write him Banzai Enterprises 2997 Anderson Ave Port Alberni British Columbia V9Y 2V3 Cana da Photo mix-up seems captions two photos July column mixed up has little bit confusion cause Please note captions photos Mike Reeds Slopar Banzai Enter prises Banzai inadvertently reversed Apol ogies concerned confused Torrey Pines Scale Fun-Fly would like chance fly Americas best-known slopes some countrys enthusias tic Scale fliers chance Thanksgiving weekend November 24-26 1989 tradi tion National Scale Slope Soaring Fun-Fly held past two years Tn-Cities WA event will three days pure Scale Soaring addition regular flying Charlie Money PR man fun-fly editor Slope Soar jog News scheduling Scale Glider demonstra tions during weekend Various manufacturers will fly planes talk about show off kits well answer questions As Charlie puts demos will entertain ing pilots spectators theyll formative interested kit buyers theyll help struggling garage-shop industry make few sales Sounds like great idea Charlie compiling mailing list interested fliers youd like get little informa tion Torrey Pines Gulls Scale Fun-Fly send name address phone number Charlie Morey Slope Soaring News 2601 E 19th Street #29 Signal Hill CA 90804 Penetrator update During recent phone call John Fotiu JM Glascraft got longawaited news larger version Penetra tor works Being about 50% larger original new version will ideal larger slopes like Eagle Butte Richland WA Coyote Hills northern California cant wait ballast up send Out 30plus lift John also has great-looking Mirage III delta wing Therell future column info Mirage new Pene trator contact John JM Glascraft 30820 May flower Roseville MI 48066 596060a better Eppler 374 Anyone has spent much time slopes has come across Eppler 374 form another Known Slope Soarers airfoil 374 has part sport years recent edition Slope Soaring Newr Charlie Money took look epic airfoil its newly derived cousin Selig-Donovan 6060 Eppler 374 semisymmetnical airfoil Slope Soaring standard Its fast offers Left Although best known being member national F3B team past four years Rich Spicer also avid Sloper Nova designed number years ago still potent Racer Right Designed unbridled speed mind Ken Gregorys Renegade reg ular California Slope Racing circuit Kens leader composite construction all-glass Renegade great example work 54 Model Aviation Radio Control Slope Soaring Mark Triebes 20794 Kreisier Cc Saratoga CA 95070 Torrey Pines No might see Scale ships like gorgeous five-meter LS-1 Tar ray Pines Scale Fun Fly held Thanksgiving weekend Photo Sailpianes International Also located NWSS booth Puyallup Gene Copes Spitfire P55 has grown leaps bounds last year Torrey Pines Scale Fun Fly will show case PSS kits Photo Wil Byers good inverted performance Aerobatics Its popular airfoils use custom Slope Racing ships Its also modified airfoils Dr Epplers stable Almost Sailplane de signer whos played 374 has found way another improve Its thinned tweaked tossed turned tilted inter est making better already Although everyone tinkers 374 attempts limited resources Typ ical approaches trial error seat-of-thepants design eyeball engineering ubiqui tous TLAR Looks About Right Only recent months has someone higher education engineering specif ically low Reynolds number aerodynamic de sign taken 374 wind tunnel analyzed its shortcomings made specific corrections eliminate Perhaps youve heard Michael Seligs air foils Seligs S3021 used Mark Allens Fal con 880 conjunction S3014 tip Mike Reeds Slopar pop ular Again its improved Eppler time popular 205 both casesthe 205 now 374 Selig decreased amount drag produced Eppler airfoils maintaining other wise similar profile June 5-7 1989 Conference Low Reynolds Numbers Aerodynamics took place University Notre Dame confer ence paper called Low Reynolds Number Air foil Design Wind Tunnel Testing Prince ton University presented J F Donovan M S Selig Mr Donovan research scientist McDonnell Douglas Research Laboratories St Louis Mr Selig graduate student Pennsyl vania State University extensive back ground model aircraft airfoil design Michael Selig kind enough provide Slope Soaring News copy paper So dictionary hand six-pack nearby Ive attempted summarize translate technicalese modelers English goes Okay lets start beginning Whats Reynolds number Its means specifying airflow over wing Reynolds numbers stated scientific notationeg 30 x 105—and refer number air molecules flowing across wing Simply put larger number air flows over wing Scientific notation allows us write very Continued page 160 Another First McDaniel RICI New Solid State On-Board Glow-Plug Drivers Now can drive ito 9 glow plugs efficiently automatically new McDaniel On-Board Glow-plug Drivers engine 2 or4 stroke glow has ito 9 cylinders On-Board Glow-Plug Drivor will ease job start ing maintaining idle during taxiing power down flight maneuvers Features Include Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Drive Up 9 Cylinders 48V 500 mAh Batteryt Includes Battery Connector & Wire Jim Rauchs slick F-4 Phantom P55 ship PuVallup Expo Photograph Wil Byers Model 475 Stiewn Optional Battery Pack Jim Magnuson duplicated paint job full-scale P-51 Obsession Word John Fotiu JM Glascrafta larger Penetra tor works Photo Jim Magnuson Another innovation McDaniel RIC kunning Time Increased Larger Battery HANDSOFFCUTII Especially Designed Tapered Wings unique device cutting high quality foam wing cores HANDS OFF cutting both sides lye same time Available hardware package assemble own board Specify 30 40 50 60 ordering Size may changed anytime Man Chord 18 standard Larger chords available Easy assemble Requires 24 Volt Variable Output Power Supply DEALERS WANTED Hands Off Cut II hardware package$87 SO 5 5 H 24 Volt Variable Output power supply 50 5 & H VIDEO FOAM SHOP Foam Shop Part OneCutting Foam Wings sour long cuts made using HANDS OFF CUT IiV H 5Only $2955 includes 5 & H lowei 48 Foam Shop Part TwoCutting Foam Fuselages hour long cuts made using simple bow VHSOnly 52995 includes 5 & H Id ei 48 SUPER BOND ACT ADHESIVE best contact cement have ever used Onip $375 8 oc squeeze bottle Enough 1400 square soC wingAdd $300 S & H lower 48 1/8 inch Phenolic Board Templates 4 X36tos ItOnly $500 * $200S & H NOR-RAY PRODUCTS Sasdbeach Road Wichita Pails Tevas 7831 Tel 8171 6924476 December 1989 55 Just time Christmas TeleHobbies R/C Network Just call 703 709-8554 favorite computer communications software RIC information electronic ordering Sign now avoid rush registration fee NO USAGE CHARGE Help design R/C hobby network want future RC supplies shipped immediately door 800 numbers coming next year RC Slope Soaring/Triebes Continued page 55 large numbers relatively brief manner example 30 x lO5 three times 10 fifth power 300000 As can see its partic ularly useful such small number get up whole number has about 72 zeros after its much easier write 30 x 1072 list 72 zeros time write number Low Reynolds numbers defined Selig-Donovan paper 500000 less wind tunnel tests slow medium fast read ings taken 60000 100000 300000 numbers very low compared associated full-scale powered aircrafthence low Reynolds Number Aero dynamics conference distinguishing characteristic air foil operated low chord Reynolds numbers Re 50 x l0 formation extensive laminar separation bubble either upper lower surfaces both bubble can signifi cantly increase drag quote pretty much sums up entire story SD6060 As air flows over top Eppler 374 breaks away sur face just past high point wing reat taches later back near trailing edge middle beneath layer detached air bub ble turbulent air forms Recognizing bubble source drag Selig set out design new airfoil minimizes drag reshaping 374 slightly Selig de creased size bubble moved ward laminar airflow could reattach wing surface sooner resulted de crease drag improved airfoil performance Does mean SD6060 will replace Eppler 374 new Slope Soaring stan dard performs well hillside did wind tunnel think will Please try let us know about results Let know tooMT Seligs wind tunnel test also confirmed leaving square edges trailing edges models flying surfaces will increase amount drag best shape trailing edge sharp Thats topic conversation local slopes lately strong support side Due experience Vader planes Dick Vader sands trailing edges paper-thin Ive learned like sharp edges other Glider designers have insisted square trailing edges actually have less drag mention auto motive design squared-off tail ends race cars break airflow suddenly reduce drag According Seligs wind tunnel tests square-edge theory hot setup suppose thatll put end ama teur aerodynamicists arguments Ill bet Ill bet youre right Charlie past few months Ive number discussions about Seligs airfoils thin vs thick trailing edges etc Having heard rumors test sections used Michael chord lengths no smaller 12 wonder about applicability smaller chords Most Slope ships have chords 6- 8-in category therefore considera bly smaller Reynolds numbers Will Selig Donovan data apply dont know Having couple semesters aerody namics am qualified challenge Michaels opinions recently read article written John Barker went great depth about difference tween Eppler 205 S3021 think conclusion just might give something think about think must accept Michael Selig has drawn some very logical conclusions formation has available own enthusi asm tempered little very small varia tions profile shape being talked about tie such things surface roughness building ability As far practical flying results concerned think important forget flavor month factor also fact new model al ways better old oneuntil have flown season Deceptive designs following piece contin ues same line thinking article written Reinhard Lahde appeared newsletter South Bay Soaring Society Silent Flyer Jim good model designer good pi lot latest creation has unusual wing planform something nobody has tried before wins several contests design appears clubs newsletter model magazine copied new planform hailed win ning planformthe Wonderwing trou ble Jims success has absolutely nothing new planform Instead has following 1 Jim good model pilot 2 has well-built model 3 streak good luck other features win ning designs too often lady luck main ingredient success Let us take good unprejudiced look what isnt important standpoint laws nature par ticular aerodynamics 1 Airfoil design selection right airfoil certainly very important among frequently discussed topics litera ture has subject various studies us ing computer programs based boundary layer theory resulting airfoil shapes painfully similar already existing ones example John Barker editor British Bat Chat news letter analyzing new profile Michael Selig expresses surprise small difference tween Selig profile other good profiles wonders about effects unavoidable building inaccuracies surface conditions covering material variances foam/glass wings Regarding allegedly supe nor flying results writes As far prac tical flying results concerned think im portant forget flavor month factor also fact new model al ways better old oneuntil have flown season s second time around statement Presumably merits thinking about MT As far know accurate reliable wind tunnel tests available Reynolds number regime interest therefore opin ion can hardly better stick what has known years example Dr Epplers research contains good solid advice select profiles Slope Racers op posed Thermal fliers plus other rules useful model design problem Dr Ep pIer fails give credit credit due mentioning granddaddy model airfoils Goettingen 549 profile appropriately scaled down thickness thermal flying bit good newer ones very similar often used Ep pIer 205 practically identical Ep pIer 176 drawn same thickness Quabeck family airfoils fishtails permit reduction drag very high coef ficients flaps deflected im portant quick turns Slope Races dont get something nothing however stands reason used Thermal flight sur face drag must slightly higher compared good non-fishtailed profile 2 Wing design wing design must pro vide adequate strength intended purpose Winch launches Slope RacingMT can pro duce forces high 60 lb subjecting wing tremendous bending moments built-up wing spar ribs use carbon fiber spar caps highly recommended 3 Interference drag interface tween fuselage wing fuselage tail surfaces inadequate design can cause considerable drag Unless interface careABELES BIGGEST SCALE PLANSSOCSAENTACSSN SERVICE PP CALE MOREL PLoNSAAAAAi.o5 P AS SAGE CATALOG405N5 32A9 Madison sboo NE 27403 ZIi SCALE OOEAMENTATrOC catalog $100 ff3LUE RIDGE MACHINERY& TOOLS P0 Box 536-Y Hurricane SIN 25526 304-562-3538 offer complete selection lathes mills tools Aviation Modeler 160 Model Aviation ________ STARLITE ST FLIGHT TRAINER 13 WFJG SPAN HAO-tM*ICE GLER EASY TO 6iAO FUN TO PLY t5ucn FLIGHtS COMPLETE QEtAKED S PAGE MANUAL SALSA & HARIYM300 IT $595 odd 45% loal oEdo JAMMASRO P0 Boo I7& AItoWk Sf1 23303 eel 8041 824 0514 pleas act $250 sIipplng doels nqwoo naIled BEETLESuperStcir6O 1987 1989 F3A World Champion Design EC LD4OTh 617W040 hREA 700 SQ IN/SPAN stANOIE 10 cA SPEC IB4G11I 6OIUING AREA 821 SQ 04/SPAN 6S/4NE 10 ae BASIC KIT $150 PREBUILT KIT $395 SPOXY .ASS PJSELAGES TORY SHEETED FOAM WING 8 STAB EPOXY/CARBON sisGRAPHITE FUSELAGE ADJUSTABLE WING MECHANISM WNO aINCLUDED PATTERN TEK iz-I4 -3L Henweemb*au esil far RrB~ fully shaped like interfaces airliners modern sailpianes might actually better separate wing fuselage use pylon mount use carbon fiber makes pos sible very light strong connecting pylon per mitting undisturbed airflow around wing fuselage 4 Wing planform As indicated earlier importance ofwing planform shape often over estimated As long some simple rules ob served exact shape wing planform has very little effect aerodynamic quality Theoret ically elliptical best true ignore effect Reynolds numbers model airplanes elliptical definitely op timum since Reynolds numbers wing tip go zero desirable tapered wing trapezoid wing rec tangular middle section better elliptical tip chord too small fact straight rectangular wing almost good espe cially washout used near wing tips approach elliptical distribution Furthermore lift aerodynamics forgiving actual lift dis tribution will always tend toward elliptical will seek middle ground between planform true ellipse 5 Sweepback Sweepback forward sweep long exaggerated has quite negligible effect wing efficiency case sweptback wing having spars also bent back bending moment transmitted center spars can resolved vectors perpen dicular planes planes oriented vertical aligned isith longitudinal axis aircraft other aligned along lateral axis aircraft mental picture becomes clearer Ed moment vectors spars resolved onto planes becomes evident mo ment vectors cancel out planes Rather resultimg moment left over must taken care structurally forgetting can lead disastrous conse quences slight amount sweepback present spar should arranged straight fashion avoid difficulties 6 Wing tip shape literature too much fuss often made wing tip shape has suggested use some magical tip shape other could significantly affectie minimizethe induced drag entirely correct Induced drag wholly function total lift b wingspan c dynamic pressure Everything else best second- third- order effect Most wing tip shapes seen good models full-size airplanes entirely adequate can hardly improved upon generate additional drag beyond unavoidable induced drag region downdraft separated region undisturbed flow two vortex tubes emanating wing tips develops behind wing reaction lift Since flow sort curls around wing tips makes sense use rounded cross section dont think can better conclusion dont just copy somebodys winning design thinking old triedand-true Clark-Y could magic airfoil next dream machine flavor month elliptical may winning won derwing As old Ronny used say Trust verify What above should teach you dont necessarily need latest design advanced innovations successful whether competition sport flying big gest mistake see fliers making assume contest-winning plane will answer problems constantly upgrading newest design making wholehearted effort learn plane theyre already flying best pilots slope thermal flying F3B other discipline advanced designs best know planes pilots concentrate flying skills can squeeze performance out airplane important part winning combination airfoil planform its pilot Slope Race results past few months three major Slope Races have held Viking F3F Slope Race Hanstholm Denmark Hans Weiss Memorial Slope Race Hughes Hills CA unofficial Slope race years Nats Washington concept international Slope Race Den mark looked like great opportunity some top Slope Racers US go head-tohead best Europe has offer Efforts John Dvorak editor SBSSs Silent Flyer CD Preben Norholm form least couple teams US seemed pay off un fortunately things didnt work out end Eventually seven teams made up 40 individual pilots following countries en tered full teams five competitors Bavaria Denmark England Germany Scotland Switzerland Two additional teams formed race Team Eli England Norwe gian team end winner race Englands Nic Wright flying Electra B3 Nic took first place contest also claimed fastest time event48 sec onds up date F3F racing 10 rounds flown competi tion pilot has flight per round flies alone against clock Ten legs flown 100-meter course total pilots scores becoming score round Average times event ran 50- 60second range top three placing teams Denmark England Norway Derbyshire England may next location F3F International Slope Race au tumn 1990 Special thanks John Dvorak providing results years race Hans Weiss Memorial Slope Race held southern California May 20-21 following report Charlie Morey lets us know turned out 'Daryll Perkins brought new plane Hughes Hill proceeded run away competition annual Hans Weiss Memorial Slope Race Although hed campaigning German-made Mueller Comet won Davenport last month time Daryll flying Mark Allens made-in-the-USA Falcon 880 proved right Slope weapon Perkins aced six consecutive heats winning outright no flyoff first glance Falcon 880 seems un likely contender Slope racing Mark Allen Flite Lite Composites designed ship hightech thermal competition machine has mild polyhedral break wing Allen gave Falcon full-house controls rudder ele vator ailerons flaps mixed electroni cally F3B-style utilized two Michael December 1989 161 Rubber & Eng Power Free Flight Display1 Control Line Electric Power RIC Airplanes new illustrated 32 page tabloid size catalog US & Canada $100 Foreign $300 Penn Valley Hobby Center 837-A W Main St Lanadale PA 19446 THE WIREMASTER er/iIer extra large handle bends 1/8-1/4 coils 5/ 32-3116 music wire Wire aeep eliminated ANTI-KREEP WIRE LOCKIB free catalog has hundreds new items free micro bender offer JCM COMPANY 114 WashIngton Terr. Waukegan IL 60085 10 FT 5-17 PLANS $4200 EPOXY GLASS COWLS PLASTIC NOSE TURRETS $5500 IAIIz 3 CATALOGS $900 THE REST IN ScALE-BaR HOLMAN O BOX 741 MA BAR BONG CA BOOS Seligs amazing airfoils starting 53021 root transitioning 53014 tips Falcon 880 Perkins raced beefed up ballasted appropriately weighed over eight pounds news Mark Allen found interesting since hed designed plane 675-lb maximum weight mind wing glassed sported arrow-shaft hinges other wise Allens original thermaling design Its truly beautiful Glider did look out place sitting ground beside straight-winged Slope Racers air another story Mark Grand modified Super Co manche garnered five wins second place Mark put home court advantage work found both lift speed outdistance Perkins RCM Magazine Soaring columnist Don Edberg placed third point behind Grand flyoff decided fourth fifth places Estancia regulars Tony Martin Jason Perrin tied nine points Tonys one-off fiberglass de sign Jasons Snipe collided flyoff Snipe going down Martins ship taking fourth overall Jerry Bridgeman unanimously voted win ner Pilots Choice trophy losing planes Jerry went through new Slope/Electric design two standard Snipes earn coveted award Special thanks go Contest Director Ray Kuntz organizing event Chuck Al len Chucks Model Shop Hawthorne trophies years Mats included F3F-style Slope Race no ones surprise Daryll Perkins ran away everyone captured first place both classes Ive opportunity watch Daryll fly couple races year its hard see successful Daryll smoothest fliers around Theres noth ing showy spectacular about way flies just very very consistent As dramatic proof take look variety planes Daryll has flown victory recent monthshis Comet Davenport Mats Falcon Hughes Hill Ron Vanns Eliminator Mats 16-oz/sq-ft limit Coming next time will look connec tion between Slope flying F3B Ill discuss ing similarities exist between two dis ciplines planes pilots RC Electrics/Kopski Continued page 57 flight highest total time four-minute segments plus fraction last partial seg ment wins thinking about event would ap proach participant set about study flight duration cruise power levels various planes idea see much en ergy storage could pack plane al locate speed control needed just maintain altitude effect applying own Rule Thumb #1 MA April 1984 page 77 says power cruise ex pressed watts input motor numerically equals weight plane pounds multi plied wing loading oz per sq foot course rule thumb approximation study involved running carefully con trolled experiments three planes First Challenger modified include geared co balt 15 10 l2-Ah SCEs speed control also ran experiments Eurekaa threechannel sport plane direct-drive Astro 25 14 1 2-Ah SCs speed control Finally ran additional experiments Nytique night-flying Amptique derivative has six 12Ah SCRs economy RC car motor pod speed control three widely varying model designs speed control installa tion such frame-rate high-rate con trols could easily swapped field flew tiring cruise-type flights collect data flight flown carefully mea sured charge ampere-minutes empty wherein charge deliberately made below batteries label capacity flights flown throttle control carefully set allow nonclimbing cruise levels power just enough throttle maintain low-altitude ovals around field Flight tests covered nearly two months under variety temperature humidity wind conditions After amassing respectable data array fol lowing conclusions clearly stood out e Rule Thumb #1 definitely does ballpark ex pected flight results just what approximation should dobut high-rate controls actual flight times vary dramatically de pending type speed control used par ticular cruise times much shorter using frame-rate controls Also case mo tor battery much hotter end flight clear heat associated framerate controls result power wasted power available turn prop fly plane long could done using high-rate controls particulars follows Challenger described above predicted cruise time about 25 minutes average time framerate control 185 minutes highrate control 304 minutes Remember no-thermal flying Eureka cruised average 66 95 minutes respectively Rule Thumb #1 prediction 98 minutes limited data short charges Nytique cruised 24 minutes 39 minutes respectively Predicted time 49 minutes As difference results between speed control types thats explainable Ill get next month now clear under conditions described model power sys tems efficient high-rate controls arc used Actually its control thats efficient rather its motor gains efficiency used high-rate controls high motor battery temperature shorter far flight times clearly show honest expected difference didnt expect such large difference Anyway some thoughts Speed controls often advertised evalu ated exclusive regard on-resistance voltage loss full Frankly con trols know use several MOSFETS metal oxide semiconductor field-effect transistors Ed parallel unless some kind basic blunder within given design should have less same small voltage dropthe same good MOSFETS available manufacturers loss really meaning full-on lossdoes story tell apparent above Besides full-on way control used servo-driven switch electronic switch would better choice May suggest youif youre planning speed control purchase intend vary speed motor modeldo strongly con sider results above course would often just cruise around described above Generally speaking youre going use speed control other full-on youre better off high-rate design would expect since nothing ever simple frame-rate types generally smaller lighter lower cost Decisions decisions Im personally familiar speed con trols high-rate ones know include Jomar SC-4 discontinued too bad SC-5 SM equivalents So also Elden Ken EKE 24U Im told RAM Red 06 have 24U use optically coupled Ill soon using Red 06 optically coupled now have obtained data J0162 Model Aviation Almost Ready Fly. Requires few hours asmbf. Includes necessary accessories/hardware. Balsa construction precovered 20-25 Size CHEROKEE 48 wing span Special 0 Size now available $11296 S&H $600 BLBW PO Box 3634 Cerritos CA 90703-3634Th@ itea~@wDealer 213 940-127020 Size 95InquiriecCOD MofleyOrdws 40 Size 95AcceptedChecks Accepted tallow 7 addItional dayst introduce new event Maxi-Flight event designed technologist strategist pilot requires continuous flight task charge pilot required land relaunch after fourth minute of
Edition: Model Aviation - 1989/12
Page Numbers: 54, 55, 160, 161, 162
BANZAI UPDATE couple columns ago pictured talked about Banzai Slope Soarer being kitted Jerry Teo Since time Banzai has undergone number changes now being kitted Banzai Mk II following notable changes original design fuselage has plywoodreinforced /5-in balsa sides wing includes spruce spar durability resistance flex damage kit now features better instruc tions scale drawings According Jerry kit retains high qual ity prefabrication materials its along introductory price will $28 US plus $350 per kit shipping han dling Jerry also mentioned Banzai Enterprises planning bringing out several kits near future following list Slope de signs firm working Combat Aero batic Delta Wing Pattern-like FAt ship BD-5 F-20 semiscale Tigershark both Unlim ited One-Meter Slope Racers Sounds great huh Drop Jerry line let him know kits youd like see first Write him Banzai Enterprises 2997 Anderson Ave Port Alberni British Columbia V9Y 2V3 Cana da Photo mix-up seems captions two photos July column mixed up has little bit confusion cause Please note captions photos Mike Reeds Slopar Banzai Enter prises Banzai inadvertently reversed Apol ogies concerned confused Torrey Pines Scale Fun-Fly would like chance fly Americas best-known slopes some countrys enthusias tic Scale fliers chance Thanksgiving weekend November 24-26 1989 tradi tion National Scale Slope Soaring Fun-Fly held past two years Tn-Cities WA event will three days pure Scale Soaring addition regular flying Charlie Money PR man fun-fly editor Slope Soar jog News scheduling Scale Glider demonstra tions during weekend Various manufacturers will fly planes talk about show off kits well answer questions As Charlie puts demos will entertain ing pilots spectators theyll formative interested kit buyers theyll help struggling garage-shop industry make few sales Sounds like great idea Charlie compiling mailing list interested fliers youd like get little informa tion Torrey Pines Gulls Scale Fun-Fly send name address phone number Charlie Morey Slope Soaring News 2601 E 19th Street #29 Signal Hill CA 90804 Penetrator update During recent phone call John Fotiu JM Glascraft got longawaited news larger version Penetra tor works Being about 50% larger original new version will ideal larger slopes like Eagle Butte Richland WA Coyote Hills northern California cant wait ballast up send Out 30plus lift John also has great-looking Mirage III delta wing Therell future column info Mirage new Pene trator contact John JM Glascraft 30820 May flower Roseville MI 48066 596060a better Eppler 374 Anyone has spent much time slopes has come across Eppler 374 form another Known Slope Soarers airfoil 374 has part sport years recent edition Slope Soaring Newr Charlie Money took look epic airfoil its newly derived cousin Selig-Donovan 6060 Eppler 374 semisymmetnical airfoil Slope Soaring standard Its fast offers Left Although best known being member national F3B team past four years Rich Spicer also avid Sloper Nova designed number years ago still potent Racer Right Designed unbridled speed mind Ken Gregorys Renegade reg ular California Slope Racing circuit Kens leader composite construction all-glass Renegade great example work 54 Model Aviation Radio Control Slope Soaring Mark Triebes 20794 Kreisier Cc Saratoga CA 95070 Torrey Pines No might see Scale ships like gorgeous five-meter LS-1 Tar ray Pines Scale Fun Fly held Thanksgiving weekend Photo Sailpianes International Also located NWSS booth Puyallup Gene Copes Spitfire P55 has grown leaps bounds last year Torrey Pines Scale Fun Fly will show case PSS kits Photo Wil Byers good inverted performance Aerobatics Its popular airfoils use custom Slope Racing ships Its also modified airfoils Dr Epplers stable Almost Sailplane de signer whos played 374 has found way another improve Its thinned tweaked tossed turned tilted inter est making better already Although everyone tinkers 374 attempts limited resources Typ ical approaches trial error seat-of-thepants design eyeball engineering ubiqui tous TLAR Looks About Right Only recent months has someone higher education engineering specif ically low Reynolds number aerodynamic de sign taken 374 wind tunnel analyzed its shortcomings made specific corrections eliminate Perhaps youve heard Michael Seligs air foils Seligs S3021 used Mark Allens Fal con 880 conjunction S3014 tip Mike Reeds Slopar pop ular Again its improved Eppler time popular 205 both casesthe 205 now 374 Selig decreased amount drag produced Eppler airfoils maintaining other wise similar profile June 5-7 1989 Conference Low Reynolds Numbers Aerodynamics took place University Notre Dame confer ence paper called Low Reynolds Number Air foil Design Wind Tunnel Testing Prince ton University presented J F Donovan M S Selig Mr Donovan research scientist McDonnell Douglas Research Laboratories St Louis Mr Selig graduate student Pennsyl vania State University extensive back ground model aircraft airfoil design Michael Selig kind enough provide Slope Soaring News copy paper So dictionary hand six-pack nearby Ive attempted summarize translate technicalese modelers English goes Okay lets start beginning Whats Reynolds number Its means specifying airflow over wing Reynolds numbers stated scientific notationeg 30 x 105—and refer number air molecules flowing across wing Simply put larger number air flows over wing Scientific notation allows us write very Continued page 160 Another First McDaniel RICI New Solid State On-Board Glow-Plug Drivers Now can drive ito 9 glow plugs efficiently automatically new McDaniel On-Board Glow-plug Drivers engine 2 or4 stroke glow has ito 9 cylinders On-Board Glow-Plug Drivor will ease job start ing maintaining idle during taxiing power down flight maneuvers Features Include Servo Reversing Optically Coupled Circuitry No RFI Automatic Shutdown Via TX RX Drive Up 9 Cylinders 48V 500 mAh Batteryt Includes Battery Connector & Wire Jim Rauchs slick F-4 Phantom P55 ship PuVallup Expo Photograph Wil Byers Model 475 Stiewn Optional Battery Pack Jim Magnuson duplicated paint job full-scale P-51 Obsession Word John Fotiu JM Glascrafta larger Penetra tor works Photo Jim Magnuson Another innovation McDaniel RIC kunning Time Increased Larger Battery HANDSOFFCUTII Especially Designed Tapered Wings unique device cutting high quality foam wing cores HANDS OFF cutting both sides lye same time Available hardware package assemble own board Specify 30 40 50 60 ordering Size may changed anytime Man Chord 18 standard Larger chords available Easy assemble Requires 24 Volt Variable Output Power Supply DEALERS WANTED Hands Off Cut II hardware package$87 SO 5 5 H 24 Volt Variable Output power supply 50 5 & H VIDEO FOAM SHOP Foam Shop Part OneCutting Foam Wings sour long cuts made using HANDS OFF CUT IiV H 5Only $2955 includes 5 & H lowei 48 Foam Shop Part TwoCutting Foam Fuselages hour long cuts made using simple bow VHSOnly 52995 includes 5 & H Id ei 48 SUPER BOND ACT ADHESIVE best contact cement have ever used Onip $375 8 oc squeeze bottle Enough 1400 square soC wingAdd $300 S & H lower 48 1/8 inch Phenolic Board Templates 4 X36tos ItOnly $500 * $200S & H NOR-RAY PRODUCTS Sasdbeach Road Wichita Pails Tevas 7831 Tel 8171 6924476 December 1989 55 Just time Christmas TeleHobbies R/C Network Just call 703 709-8554 favorite computer communications software RIC information electronic ordering Sign now avoid rush registration fee NO USAGE CHARGE Help design R/C hobby network want future RC supplies shipped immediately door 800 numbers coming next year RC Slope Soaring/Triebes Continued page 55 large numbers relatively brief manner example 30 x lO5 three times 10 fifth power 300000 As can see its partic ularly useful such small number get up whole number has about 72 zeros after its much easier write 30 x 1072 list 72 zeros time write number Low Reynolds numbers defined Selig-Donovan paper 500000 less wind tunnel tests slow medium fast read ings taken 60000 100000 300000 numbers very low compared associated full-scale powered aircrafthence low Reynolds Number Aero dynamics conference distinguishing characteristic air foil operated low chord Reynolds numbers Re 50 x l0 formation extensive laminar separation bubble either upper lower surfaces both bubble can signifi cantly increase drag quote pretty much sums up entire story SD6060 As air flows over top Eppler 374 breaks away sur face just past high point wing reat taches later back near trailing edge middle beneath layer detached air bub ble turbulent air forms Recognizing bubble source drag Selig set out design new airfoil minimizes drag reshaping 374 slightly Selig de creased size bubble moved ward laminar airflow could reattach wing surface sooner resulted de crease drag improved airfoil performance Does mean SD6060 will replace Eppler 374 new Slope Soaring stan dard performs well hillside did wind tunnel think will Please try let us know about results Let know tooMT Seligs wind tunnel test also confirmed leaving square edges trailing edges models flying surfaces will increase amount drag best shape trailing edge sharp Thats topic conversation local slopes lately strong support side Due experience Vader planes Dick Vader sands trailing edges paper-thin Ive learned like sharp edges other Glider designers have insisted square trailing edges actually have less drag mention auto motive design squared-off tail ends race cars break airflow suddenly reduce drag According Seligs wind tunnel tests square-edge theory hot setup suppose thatll put end ama teur aerodynamicists arguments Ill bet Ill bet youre right Charlie past few months Ive number discussions about Seligs airfoils thin vs thick trailing edges etc Having heard rumors test sections used Michael chord lengths no smaller 12 wonder about applicability smaller chords Most Slope ships have chords 6- 8-in category therefore considera bly smaller Reynolds numbers Will Selig Donovan data apply dont know Having couple semesters aerody namics am qualified challenge Michaels opinions recently read article written John Barker went great depth about difference tween Eppler 205 S3021 think conclusion just might give something think about think must accept Michael Selig has drawn some very logical conclusions formation has available own enthusi asm tempered little very small varia tions profile shape being talked about tie such things surface roughness building ability As far practical flying results concerned think important forget flavor month factor also fact new model al ways better old oneuntil have flown season Deceptive designs following piece contin ues same line thinking article written Reinhard Lahde appeared newsletter South Bay Soaring Society Silent Flyer Jim good model designer good pi lot latest creation has unusual wing planform something nobody has tried before wins several contests design appears clubs newsletter model magazine copied new planform hailed win ning planformthe Wonderwing trou ble Jims success has absolutely nothing new planform Instead has following 1 Jim good model pilot 2 has well-built model 3 streak good luck other features win ning designs too often lady luck main ingredient success Let us take good unprejudiced look what isnt important standpoint laws nature par ticular aerodynamics 1 Airfoil design selection right airfoil certainly very important among frequently discussed topics litera ture has subject various studies us ing computer programs based boundary layer theory resulting airfoil shapes painfully similar already existing ones example John Barker editor British Bat Chat news letter analyzing new profile Michael Selig expresses surprise small difference tween Selig profile other good profiles wonders about effects unavoidable building inaccuracies surface conditions covering material variances foam/glass wings Regarding allegedly supe nor flying results writes As far prac tical flying results concerned think im portant forget flavor month factor also fact new model al ways better old oneuntil have flown season s second time around statement Presumably merits thinking about MT As far know accurate reliable wind tunnel tests available Reynolds number regime interest therefore opin ion can hardly better stick what has known years example Dr Epplers research contains good solid advice select profiles Slope Racers op posed Thermal fliers plus other rules useful model design problem Dr Ep pIer fails give credit credit due mentioning granddaddy model airfoils Goettingen 549 profile appropriately scaled down thickness thermal flying bit good newer ones very similar often used Ep pIer 205 practically identical Ep pIer 176 drawn same thickness Quabeck family airfoils fishtails permit reduction drag very high coef ficients flaps deflected im portant quick turns Slope Races dont get something nothing however stands reason used Thermal flight sur face drag must slightly higher compared good non-fishtailed profile 2 Wing design wing design must pro vide adequate strength intended purpose Winch launches Slope RacingMT can pro duce forces high 60 lb subjecting wing tremendous bending moments built-up wing spar ribs use carbon fiber spar caps highly recommended 3 Interference drag interface tween fuselage wing fuselage tail surfaces inadequate design can cause considerable drag Unless interface careABELES BIGGEST SCALE PLANSSOCSAENTACSSN SERVICE PP CALE MOREL PLoNSAAAAAi.o5 P AS SAGE CATALOG405N5 32A9 Madison sboo NE 27403 ZIi SCALE OOEAMENTATrOC catalog $100 ff3LUE RIDGE MACHINERY& TOOLS P0 Box 536-Y Hurricane SIN 25526 304-562-3538 offer complete selection lathes mills tools Aviation Modeler 160 Model Aviation ________ STARLITE ST FLIGHT TRAINER 13 WFJG SPAN HAO-tM*ICE GLER EASY TO 6iAO FUN TO PLY t5ucn FLIGHtS COMPLETE QEtAKED S PAGE MANUAL SALSA & HARIYM300 IT $595 odd 45% loal oEdo JAMMASRO P0 Boo I7& AItoWk Sf1 23303 eel 8041 824 0514 pleas act $250 sIipplng doels nqwoo naIled BEETLESuperStcir6O 1987 1989 F3A World Champion Design EC LD4OTh 617W040 hREA 700 SQ IN/SPAN stANOIE 10 cA SPEC IB4G11I 6OIUING AREA 821 SQ 04/SPAN 6S/4NE 10 ae BASIC KIT $150 PREBUILT KIT $395 SPOXY .ASS PJSELAGES TORY SHEETED FOAM WING 8 STAB EPOXY/CARBON sisGRAPHITE FUSELAGE ADJUSTABLE WING MECHANISM WNO aINCLUDED PATTERN TEK iz-I4 -3L Henweemb*au esil far RrB~ fully shaped like interfaces airliners modern sailpianes might actually better separate wing fuselage use pylon mount use carbon fiber makes pos sible very light strong connecting pylon per mitting undisturbed airflow around wing fuselage 4 Wing planform As indicated earlier importance ofwing planform shape often over estimated As long some simple rules ob served exact shape wing planform has very little effect aerodynamic quality Theoret ically elliptical best true ignore effect Reynolds numbers model airplanes elliptical definitely op timum since Reynolds numbers wing tip go zero desirable tapered wing trapezoid wing rec tangular middle section better elliptical tip chord too small fact straight rectangular wing almost good espe cially washout used near wing tips approach elliptical distribution Furthermore lift aerodynamics forgiving actual lift dis tribution will always tend toward elliptical will seek middle ground between planform true ellipse 5 Sweepback Sweepback forward sweep long exaggerated has quite negligible effect wing efficiency case sweptback wing having spars also bent back bending moment transmitted center spars can resolved vectors perpen dicular planes planes oriented vertical aligned isith longitudinal axis aircraft other aligned along lateral axis aircraft mental picture becomes clearer Ed moment vectors spars resolved onto planes becomes evident mo ment vectors cancel out planes Rather resultimg moment left over must taken care structurally forgetting can lead disastrous conse quences slight amount sweepback present spar should arranged straight fashion avoid difficulties 6 Wing tip shape literature too much fuss often made wing tip shape has suggested use some magical tip shape other could significantly affectie minimizethe induced drag entirely correct Induced drag wholly function total lift b wingspan c dynamic pressure Everything else best second- third- order effect Most wing tip shapes seen good models full-size airplanes entirely adequate can hardly improved upon generate additional drag beyond unavoidable induced drag region downdraft separated region undisturbed flow two vortex tubes emanating wing tips develops behind wing reaction lift Since flow sort curls around wing tips makes sense use rounded cross section dont think can better conclusion dont just copy somebodys winning design thinking old triedand-true Clark-Y could magic airfoil next dream machine flavor month elliptical may winning won derwing As old Ronny used say Trust verify What above should teach you dont necessarily need latest design advanced innovations successful whether competition sport flying big gest mistake see fliers making assume contest-winning plane will answer problems constantly upgrading newest design making wholehearted effort learn plane theyre already flying best pilots slope thermal flying F3B other discipline advanced designs best know planes pilots concentrate flying skills can squeeze performance out airplane important part winning combination airfoil planform its pilot Slope Race results past few months three major Slope Races have held Viking F3F Slope Race Hanstholm Denmark Hans Weiss Memorial Slope Race Hughes Hills CA unofficial Slope race years Nats Washington concept international Slope Race Den mark looked like great opportunity some top Slope Racers US go head-tohead best Europe has offer Efforts John Dvorak editor SBSSs Silent Flyer CD Preben Norholm form least couple teams US seemed pay off un fortunately things didnt work out end Eventually seven teams made up 40 individual pilots following countries en tered full teams five competitors Bavaria Denmark England Germany Scotland Switzerland Two additional teams formed race Team Eli England Norwe gian team end winner race Englands Nic Wright flying Electra B3 Nic took first place contest also claimed fastest time event48 sec onds up date F3F racing 10 rounds flown competi tion pilot has flight per round flies alone against clock Ten legs flown 100-meter course total pilots scores becoming score round Average times event ran 50- 60second range top three placing teams Denmark England Norway Derbyshire England may next location F3F International Slope Race au tumn 1990 Special thanks John Dvorak providing results years race Hans Weiss Memorial Slope Race held southern California May 20-21 following report Charlie Morey lets us know turned out 'Daryll Perkins brought new plane Hughes Hill proceeded run away competition annual Hans Weiss Memorial Slope Race Although hed campaigning German-made Mueller Comet won Davenport last month time Daryll flying Mark Allens made-in-the-USA Falcon 880 proved right Slope weapon Perkins aced six consecutive heats winning outright no flyoff first glance Falcon 880 seems un likely contender Slope racing Mark Allen Flite Lite Composites designed ship hightech thermal competition machine has mild polyhedral break wing Allen gave Falcon full-house controls rudder ele vator ailerons flaps mixed electroni cally F3B-style utilized two Michael December 1989 161 Rubber & Eng Power Free Flight Display1 Control Line Electric Power RIC Airplanes new illustrated 32 page tabloid size catalog US & Canada $100 Foreign $300 Penn Valley Hobby Center 837-A W Main St Lanadale PA 19446 THE WIREMASTER er/iIer extra large handle bends 1/8-1/4 coils 5/ 32-3116 music wire Wire aeep eliminated ANTI-KREEP WIRE LOCKIB free catalog has hundreds new items free micro bender offer JCM COMPANY 114 WashIngton Terr. Waukegan IL 60085 10 FT 5-17 PLANS $4200 EPOXY GLASS COWLS PLASTIC NOSE TURRETS $5500 IAIIz 3 CATALOGS $900 THE REST IN ScALE-BaR HOLMAN O BOX 741 MA BAR BONG CA BOOS Seligs amazing airfoils starting 53021 root transitioning 53014 tips Falcon 880 Perkins raced beefed up ballasted appropriately weighed over eight pounds news Mark Allen found interesting since hed designed plane 675-lb maximum weight mind wing glassed sported arrow-shaft hinges other wise Allens original thermaling design Its truly beautiful Glider did look out place sitting ground beside straight-winged Slope Racers air another story Mark Grand modified Super Co manche garnered five wins second place Mark put home court advantage work found both lift speed outdistance Perkins RCM Magazine Soaring columnist Don Edberg placed third point behind Grand flyoff decided fourth fifth places Estancia regulars Tony Martin Jason Perrin tied nine points Tonys one-off fiberglass de sign Jasons Snipe collided flyoff Snipe going down Martins ship taking fourth overall Jerry Bridgeman unanimously voted win ner Pilots Choice trophy losing planes Jerry went through new Slope/Electric design two standard Snipes earn coveted award Special thanks go Contest Director Ray Kuntz organizing event Chuck Al len Chucks Model Shop Hawthorne trophies years Mats included F3F-style Slope Race no ones surprise Daryll Perkins ran away everyone captured first place both classes Ive opportunity watch Daryll fly couple races year its hard see successful Daryll smoothest fliers around Theres noth ing showy spectacular about way flies just very very consistent As dramatic proof take look variety planes Daryll has flown victory recent monthshis Comet Davenport Mats Falcon Hughes Hill Ron Vanns Eliminator Mats 16-oz/sq-ft limit Coming next time will look connec tion between Slope flying F3B Ill discuss ing similarities exist between two dis ciplines planes pilots RC Electrics/Kopski Continued page 57 flight highest total time four-minute segments plus fraction last partial seg ment wins thinking about event would ap proach participant set about study flight duration cruise power levels various planes idea see much en ergy storage could pack plane al locate speed control needed just maintain altitude effect applying own Rule Thumb #1 MA April 1984 page 77 says power cruise ex pressed watts input motor numerically equals weight plane pounds multi plied wing loading oz per sq foot course rule thumb approximation study involved running carefully con trolled experiments three planes First Challenger modified include geared co balt 15 10 l2-Ah SCEs speed control also ran experiments Eurekaa threechannel sport plane direct-drive Astro 25 14 1 2-Ah SCs speed control Finally ran additional experiments Nytique night-flying Amptique derivative has six 12Ah SCRs economy RC car motor pod speed control three widely varying model designs speed control installa tion such frame-rate high-rate con trols could easily swapped field flew tiring cruise-type flights collect data flight flown carefully mea sured charge ampere-minutes empty wherein charge deliberately made below batteries label capacity flights flown throttle control carefully set allow nonclimbing cruise levels power just enough throttle maintain low-altitude ovals around field Flight tests covered nearly two months under variety temperature humidity wind conditions After amassing respectable data array fol lowing conclusions clearly stood out e Rule Thumb #1 definitely does ballpark ex pected flight results just what approximation should dobut high-rate controls actual flight times vary dramatically de pending type speed control used par ticular cruise times much shorter using frame-rate controls Also case mo tor battery much hotter end flight clear heat associated framerate controls result power wasted power available turn prop fly plane long could done using high-rate controls particulars follows Challenger described above predicted cruise time about 25 minutes average time framerate control 185 minutes highrate control 304 minutes Remember no-thermal flying Eureka cruised average 66 95 minutes respectively Rule Thumb #1 prediction 98 minutes limited data short charges Nytique cruised 24 minutes 39 minutes respectively Predicted time 49 minutes As difference results between speed control types thats explainable Ill get next month now clear under conditions described model power sys tems efficient high-rate controls arc used Actually its control thats efficient rather its motor gains efficiency used high-rate controls high motor battery temperature shorter far flight times clearly show honest expected difference didnt expect such large difference Anyway some thoughts Speed controls often advertised evalu ated exclusive regard on-resistance voltage loss full Frankly con trols know use several MOSFETS metal oxide semiconductor field-effect transistors Ed parallel unless some kind basic blunder within given design should have less same small voltage dropthe same good MOSFETS available manufacturers loss really meaning full-on lossdoes story tell apparent above Besides full-on way control used servo-driven switch electronic switch would better choice May suggest youif youre planning speed control purchase intend vary speed motor modeldo strongly con sider results above course would often just cruise around described above Generally speaking youre going use speed control other full-on youre better off high-rate design would expect since nothing ever simple frame-rate types generally smaller lighter lower cost Decisions decisions Im personally familiar speed con trols high-rate ones know include Jomar SC-4 discontinued too bad SC-5 SM equivalents So also Elden Ken EKE 24U Im told RAM Red 06 have 24U use optically coupled Ill soon using Red 06 optically coupled now have obtained data J0162 Model Aviation Almost Ready Fly. Requires few hours asmbf. Includes necessary accessories/hardware. Balsa construction precovered 20-25 Size CHEROKEE 48 wing span Special 0 Size now available $11296 S&H $600 BLBW PO Box 3634 Cerritos CA 90703-3634Th@ itea~@wDealer 213 940-127020 Size 95InquiriecCOD MofleyOrdws 40 Size 95AcceptedChecks Accepted tallow 7 addItional dayst introduce new event Maxi-Flight event designed technologist strategist pilot requires continuous flight task charge pilot required land relaunch after fourth minute of