HUMBUG 91 OLD-TIMER Nostalgia events competitive models have grown point rival corresponding contemporary events popularity Control Line Stunt no exception trend attraction old-time pre 1952 stunt planes unique personalities since typically offer performance presentday contest models Some Nostalgia stunters designs 25 years old exhibit performance equal greater present-day models Such case Humbug flapless 19-powered Humbug conceived 1966 Bill Netzeband clearly radical Revised version 1966 design Nostalgia Stunt flying features nonlinear control system U Robert Baron departure designs period Though approximately same wing area its competition Humbug used engine half size flapped stunters day attack pattern vengeance using full 70 feet line event allows Since flown days muffled engine too anemic acceptable performance high-revving Veco 19 produced earsplitting noise turning 8 x 5 prop about 12000 rpm Humbug never galned much acceptance stunt community becauseof its deviant appearance noisy engine example plane scored highest flying points two Nationals events finished out running due low static points 40 points available time Clearly performance package lacking fact fellow modeler said good-looking Humbug would oxymoron thought would interesting revisit unusual plane see flew after updating modem engine revised control system some structural improve ments new version equipped withan OS 28a muffler nonlinear control system carbon fiber wing spars has resulted plane silly Thats righta plane makes giggle updated power plant Humbug 91 can easily consecutive vertical square eights followed consecutive hourglasses After flying plane began wonder what would have happened stunt per formance rather package ruled roost last 25 years modifications spirit Nostalgia Stunt flying has maintained appearance original essentially unchanged Aside slight change nose length accommodate added weight muffler minor reduction rudder height outward appearance indistinguishable original except avid aficionados Critical changes structure control system power plant have incorporated modifica tions improve Humbugs performance life changing its fundamental character first change upgrading power plant easy engines have come market last 20 years substantial increases horsepower due Schnuerle porting better metallurgy closer manufacturing tolerances Schnuerle-type engine partic ularly suited Humbug design requirement constant high rpm rather traditional two- four-cycle run normally used Stunt An OS 28 used because its excellent construction twin ball bearings light weight engine comes effective muffler significant back pressure stock muffler power significantly greater original Clarence Lee-modified Veco 19 proved excellent selection OS readily turns 91/2-inch prop well enough result same fivesecond lap times original 26 Model Aviation 4Robert Baron Humbug 91 1966 version used Veco 19 power model uses muffled OS 32 Profile view shows tricycle landing gear Humbug 91 uses modern construction techniques retains appearance original engine has superseded OS 32 slightly heavier because fins cylinder larger otherwise very similar 32 turns prop es greater diameter old Veco 19 could resulting much thrust during maneuvers counts enables model corner harder original main taining sufficient speed clean exit tank set up run either conventional vent uniflo muffler pressure best runs obtained using uniflo no muffler pressure engine set just below maximum power runs hard two-cycle entire flight Fuel 10% nitro inlet diameter 250 inches muffler exhaust opening enlarged stock diameter 250 inches 270 inches 010 head gasket used addition stock gasket T greatest potential improvement after two decades progress change construction techniques did see compelling need change some structure main spar particular also assembly sequence used second time around almost completely reverse original main structural problem previous Humbugs severe cornering loads fatigued broke wood wing spar after few hundred flights performance plane degenerated Part problem spars carried through original models center section also suspected wood fatigue particularly since MonoKote used place paint paint adds substantial amount strength wood new version unidirectionai carbon fiber glued opposite sides -inch-square spars carried through center joined two pieces -inch square spar carbon fiber does bond particularly well balsa compression carbon fiber peels away under relatively little load bonding carbon fiber opposite sides side always tension minimizes amount spar can deflect Using technique rela tively low peel strength carbonfiber-to-balsa bond circumvented essence spar becomes I-beam two spars joined vertical shear webs entire structure becomes extremely stiff torsional strength wing nor significantly improved use carbon fiber spars does appear serious problem Im sure however additional torsional stiffness would improve stability wind tried use carbon tows running 450 angles between ribs develop torsional stiffness could get sufficiently reliable bond between balsa carbon fiber sheeting ribs able transmit loads fibers tried various brands cyanoacrylate CyA glues acceler ators success Bonding unidi rectional fibers epoxy throughout wing frame too tedious abandoned further attempts incor porate carbon fiber structure fter addressing structural problems original Humbug finding suitable modern power plant/muffler combination next challenge control system by-product exceptional performance original plane its control sensitivity level flight round maneuvers necessitated hours practice stability problemthe Humbug stable control inputs necessary level flight round maneuvers subtle hard make minor corrections desired control system slowed inputs low control deflections less 100 allowed full control needed squares Such system designed Bill Netzeband 10 years ago incorporated revolutionary /2A stunter called Barecat Bill found unless such system incorporated Humbug-type model airplanes performance would always have backed off because limitations imposed need fly level still able perform accurate round maneuvers nonlinear system analogous variable-ratio steering automobile results dramatic improvement ability fly level execute round maneuvers sacrificing planes ultimate performance square 30% increase speed control system extremes travel results corresponding 30% loss mechanical advantage means unless control forces kept light through aerodynamic balancing small moving surfaces system will unable generate enough torque full travel controls Such case conventional flapped stunterthe high binge moments required actuate flaps too much control system handle important remember control line system limited force available force limited line tension generated centrifugal force plane Once July1993 27 Fuselage cut near airfoils high point allow stabilizer installation CG adjustment nose section ot iuseiage used spacer locate slotted center wing ribs Wing spars LE TE sheeting cap strips some shear webs have installed point Belicrank mount nonlinear control system installed below rib centerline transfer arm clearance -inch sheet balsa stabilizer covered prior installation slotted attachment points control deflection demands exceed can generated line tension no additional deflection hence lift can obtained system requires careful fitting installation way accurately establish critical slot hole locations using millthe tolerances too demanding hand work Note particularly important system neutral position elevator neutral up down control response will significantly different addition length control horn elevator does simply change sensitivity handle system length elevator control horn determines maximum travel elevator determines extent nonlinear aspects system will observed flight properties airplane different conven tional system elevator horn length changes relationship between handle movement control deflection standpoint control sensitivity changing handle width conventional system will have effect identical changing horn length Because critical nature horn length relation rest control system slot machined horn effective length made infinitely adjustable over anticipated range adjusting horn length maximum travel elevator changed until cornering ability associated speed loss through corner liking handle width altered adjust sensitivity plane adjusting done after center gravity CG positioned per drawings simplicity conventional control system shown plans can substituted will some loss performance reasons stated above CONSTRUCTION fuselage made first since its exact width needed accurately locate center ribs Notice fuselage made piece would conventional plane cut two near high point wing necessary install aft fuselage around stabilizer attached before fuselage added allow nose length altered adjust center gravity construction nose can sawed off center still made fit wing aft body Depending engine/muffler combination used CU can altered adjusting nose length minimizes ballast requirements bottom block should glued permanently top block should tack-glued removal installing aft fuselage around stabilizer Note cowling hold-down consists two screws front tie blind nuts located 3A2 plywood nm two screws side body tie tabs cowling reason tabs no room conventional attachment point rear cowling since tank vents landing gear mount tank installation would interfere bottom portion fuselage forward fuselage break /8 Lite Ply grain running fore aft provide nose gear mount Under neath plywood l/ balsa grain running across fuselage adds significant stiffness bottom very little weight increase Blind nuts used conjunction nylon clips fasten nose gear One-eighth-inch aluminum plates used under engine prevent denting bearers engine bolted Once fuselage complete wing construction can started ribs made placing thirteen 342-inch sheets between 1A6 plywood templates drilling precise 3/s-inchdiameter holes installing brass tube hole prior carving rib stacks down templates holes ribs best cut using drill press sharpened piece 3/ brass tubing conventional drill bit will produce very poor quality hole drilling through stack balsa ribs marked will oriented jig bars same way during carving process cancels out error introduced jig alignment holes exactly centerline ribs After ribs made innermost outermost ribs traced cut -inch sheet balsa two ribs need made wider facilitate construction provide additional strength ribs slid onto jig bars use jig bars demon strated years ago Al Rabe far away accurate way construct built-up wing does work exceptionally well does increase construction time actually makes wing go together very easily Now should evident fuselage constructed first two -inch-sheet center ribs must located exact fuselage width since will important glue joint attach fuselage wing Use fuselage nose portion 28 Model Aviation covering slotted same manner stabi lizer receive rear fuselage section CG position determined pinning nose section place temporarily attaching hardware Incidence meter level used ensure thrustline wing centerline parallel Jig attaches engine mounts supports model comfortable heiaht durina finishina match wing color fuselage finished automotive lacquer over dope tissue talc Full Size Plans AvailableSee Page 184 -r CONVENTIONAL MELLORANE RUTFINL11 - IWINO HUMBUG 91 spacer locate center ribs prior attaching trailing edge sheeting leading edge spars Note slots center ribs bellcrank platform different depending control system used After trailing edge sheeting leading edge spars place landing gear mounts leading edge sheeting installed Tilt assembly edge run CyA glue down rib/sheet joint sure joints secure Install vertical shear webs position jig bars will allow glue shear webs between trailing edge planking Install -inch-wide cap strips ribs lightly block sand wing point structure relatively rigid stable alignment bars can removed best done attaching drill motor bars slowly spinning pulled structure Install remainder vertical shear webs blocked jig bars install belicrank mount controls can now added conventional bellcrank system used belicrank mount can installed centerline ribs non linear system used bellcrank mount must lowered allow height required transfer arm Complete wing installing pushrod wing tips wing tip box center section planking wing tip unusual centerline leadout guide installed 4 inch below centerline wing compensate vertical center gravity being below wing center line because weight engine landing gear guide location determined empirically hanging plane leadouts trying different locations sighting against plumb bob until proper position determined Cut window top center section planking completed wing neutral position bellcrank can seen will important stabilizer/elevator installed wing can now covered MonoKote July1993 29 tIIfl Type Nostalgia CL Stunt Wingspan 561/2 inches Recommended engine size type 05 32 muffler Type construction Built-up Type of covering/finish recommended MonoKote wing stabilizer booms automotive lacquer over tissue talc dope fuselage After final trim applied clear acrylic enamel used complete fuelproofing Highly modified Zinger 10 x 5 prop has worked best Humbua 91 Full details text Nose length rudder height visible differences between Humbug 91 original CENTURY JET MODELS INC 8 Martha Ct Sumter SC 29150 803 775-6491 RETRACT SELECTOR SPEED CONTROL VALVE 8305 Regency Woods Way Louisville KY 40220 502 491-4114 Four Infinite Adjustment Screws 2 Up 2 Down Compatible air system Dim 3/8 xls 1-1/4 $2495 Wt 15 oz Semi & Deluxe Ducted Fan Jet Kits Eposy fiberglass fuselage canopy foam wings plans instructions Intake/Exhaust System euc F-i 00 F-100 Hun basic kit $18999 1/8 Scale 50 Removable Wings Length 63 Sport Hawk MK II basic kit $18988 e P&H Easy buildl Removable wing Length 59 F-105 Thunderchief basic kit $23900 e P&H Length 73 77-91 Engine No Cheater Hole F-4 Phantom basic kit $59900 HEW 1/7 Scale Twin Engine Aileron/Spoiler Config Length 90 Removable 61 Wings LE/TE flaps Deluse kit DC wood I/B pylons CF kit plus morel Landing gear tires brakes available FLY THE F-100 SUPER SABRE FROM COMPARE OUR RETRACTS TO THEIRS Stainless Struts cut FREEl Stainless Torque Linksl Different strut configurations * 1 Year Limited Warranty GIANT MAIN RETRACTS STANDARD OR 900 ROTAl 30-50 lb aircraft 2 sets 1 Standard 900 minutes 7Q0 1100 retract angle Over-center lock down Nose gear available $27500 pair Wt 15 lbs Complete Air System Axle Installed Parts Service 30 Day Refund SCALE MAIN RETRACTS STANDARD OR 900 ROTATE Fits PICA Skys F-Si 1/5 Yellow A/C Ziroli Bud Nosen plus Choice 91 Plyon Winners Handles 20-25 lb aircraft 8497 retract angle Positive lock up lock down Optional wire struts Nose gear available $19900 pair Wt 22 oz NEW 1/5 SCALE P-Si & SPITFIRE products proudly MADE IN THE USAI TIRED OF DRAGGING YOUR WING TIPS ON ThE GROUND. WV DUCTS FOR VIOJETT OR DYNAMAX PLEASE SPECIFY VERY COMPLETE KIT F100....... $550 VIDEO TAPE MANUAL $20 F100 DEMO TAPE .$10 FREE PITOT POWER$8SSH OFFSET DOOR HINGES B FOR $8 CALL FOR QUANTITY PRICES USHER ENTERPRISES INC 1017 SE FRONTAGE RD BOX 511 NORTH PLAINS OR 97133 503647 0015 booms made next sandwiching length Y32 plywood between two pieces 3/ts balsa makes extremely stiff light boom t/2 ounce Mono Kote covering wrapped around edge joins wing Cut away just enough effect good bond wing Cut away just enough MonoKote wing good glue jointso no bare wood exposed outboard booms booms glued wing using slow-curing epoxy gives time accurately align well wipe away excess glue alcohol thinner stabilizer elevator made U -inch sheet balsa covered MonoKote prior installation cutting slots covering per booms stabilizer now glued booms taking care locate accurately relative wing Note body glued time placed wing reference stabilizer alignment Now look window wing center section planking place bellcrank neutral position Tape pushrod wing cannot move pushrod attached elevator horn elevator temporarily held place hinges glue hinges time clevis adjusted until elevator neutral pushrodlbellcrank maintained neutral position point release tape pushrod check action controls Remove top block rear portion fuselage install aft body around stabilizer taking care put load stabilizer Cut slots MonoKote attach rear fuselage wing Glue top block cut slot fin At this point nose portion use age can pinned place center gravity can determined installing hardware plane nose heavy fuselage can cut center section shortened until proper center gravity approximately t/8 inch front position shown plans weight fillets paint will shift center gravity slightly aft entire plane painted rather covered MonoKote will have guess weight paint its effect center gravity determine nose length will require minimum ballast Glue fuselage slow-curing epoxy using Robart incidence meter conjunction bubble level ensure thrustline parallel wing centerline Glass nose using 3¼-ounce cloth epoxy fin can permanently glued fuselage canopy added complete framing aircraft fuselage can painted per favorite finishing technique model standard dope tissue talc finish used fillthe grain Since commercial modeling dopes good match Continued page 38 30 Model Aviation t day Saturday OUTLAWFAI COM BAT FIrst match starts 1000 am Saturday Entry Fee $700Open Juniors $500 Sponsored Betty Fox Doc Passen Awards prizes third place Special prize highest place Junior Second day Sunday SUPER-SLOW COMBAT Entry Fee $1000Open Juniors $500 Sponsored FOX Manufacturing DoCs Generix Controline Kits Doc Passen Contest Director information call Write PO Box 111 Jasonville IN 47438 Telephone 812 665-3723 2 days Control Line Combat Wood Hand Selected Fiberglass Cowl Complete Plans Parts Hand Cut Instruction Manual Photo Page order kits call 1-800-327-7198 catalog fine kits send $400Idaho Residents Add 5% State Sales Tax Gasoline fueled Produces 3 foot flame will power planes up 228 mph Designed FUN EASY build home shop about 8 hours using materials already have such aerosol spray can combustion chamber Only simple hand tools needed Both high performance jet engines FUN EASY build STEP BY STEP DETAILED FULL SIZE plan sets complete fuel ignition systems JOIN THE JET AGE sending $995 3hp plan set $1295 7hp plan set both sets $2000 JET ENGINE10241 Ridgewood El Paso Texas 79925 AFTER YOU DID ALL THE WORK WHY LET YOUR AIRPLANE DO ALL THE FLYING HumbuglBaron Continued page 30 white MonoKote used automotive lacquer After trim paint canopy can sealed Ditzler acrylic enamel completely fuel proof finish applying final clear coat recommended masking tape placed slightly outside fillet enamel can run around edge fillet seal edge use 3M fine line tape masking gives clean edge leaves no residue removed Remember pull tape off enamel still tacky prevent bonding tape plane allow enamel seal edge During finish workincluding doping applying paper fillets spraying maskingI use ajig attaches engine mounts suspends plane comfortable height Complete paint trim rudder elevator hinging landing gear installation plane held jig FLYING AND TRIMMING Since Humbug has no flaps easier adjust conventional stunter First install ballast required position center gravity shown plans stability standpoint plane will tolerate aft center gravity line tension positive under varied condi tions center gravity aft position shown plans Set leadouts line shown plans Test flights should short lines 62-64 feet x 015 safety Once model trimmed out 65-68 feet optimum Place approximately e weight tip box Adjust elevator horn provide 250 travel direction started four-inch-wide handle As stunters prop selection criti cal amazing little piece wood can affect flight performance prefer wood propsthey readily modified light weight keeps precession minimum get stunt plane pitch gauge must can make blades accurate pitch gauge can also determine exactly way need adjust pitch obtain desired performance general lower pitch greater vertical capability provided engine can turn prop fast enough give adequate airspeed Increasing pitch will increase airspeed will also increase tendency whip up windy conditions Increased diameter also increases vertical capability cost increased whip-up wind Changing blade shape alters power requirements may cause corresponding change airspeed thrust Finding trade-off between diameter pitch blade shape challenge Humbug 91 can save some time giving dimensions best prop date Start Zinger Continued page 129 38 Model Aviation 4PUGNACIOUS PUSSY CAT 1/4 scale Gee Bee Model Y 9017 lbs 3 7 HP PULSE JET ENGINES AVAILABLE BUILD & FLY THE miniMAX VflI IRFI Fl ampion ana- uomputer uesigneoMss serve Urand unampion ultralightPart 103 UltralightEasy construction 1989 Sun-N-Pun Fly-InWood construction TEAM INC 10790-MA Ivy Bluff Rd Bradyville TN 37026615-765-5397 HumbuglBaron Continued page 38 10 x 5 measured pitch 46 5 inches de-pitch true 40 inches stations Next cut diameter 91/2 inches using dial calipers exactly measure blades length carve sweep leading edge starting approximately inch tip ending tip diameter about 1/ inch Balance blade minimize vibration Carefully check flying site presence small rocks tricycle landing gear thin prop turning high rpm can easily broken leading shaft run can damage airframe Set engine hard two-cycle clearly off maximum power 91/2 x 4 prop lap times should 4 5 seconds Check wings level both upright inverted flight wing high steam wing over kettle boiling water until model flies level both upright inverted found wing obviously need steaming based initial flights warp readily detected sighting down trailing edge event steam wing direction indicated attitude plane level flight wing high both directions add tip weight low both ways remove weight Next make sure engine running same both attitudes Checking lap times both upright inverted good way determine tank needs shimming plane slower right-sideup inverted shim tank down until lap times way close equal Once above steps have completed final trimming matter adjusting control travel trade off cornering against loss airspeed adjusting handle width suit needs ended up 220 elevator travel Minor adjustments leadout rake can made adjusting up line improve inside maneuvers down line outside maneuvers Small changes prop diameter 1/s inch time will result tighter slower corners diameter decreased opposite effect diameter increased As high-performance vehicle very small adjustments have significant effects flight character istics 1/s-inch change leadout rake few mph change airspeed will readily noticed handle possible adjustments very wide range performance handling characteristics available flier Humbug will utilize trimming flying skills hand can trimmed fly like trainer other can trimmed deliver performance tax experienced pilot make choice ess Series U-Control Kits Beginners *0 06 wests new Success Series 049 U-Control kits perfect introduction building flying Featuring illustrated step-by-step Success Series construction manuals teach build paint fly models Kits include Micro-Cut Quality parts pre-formed wire parts wheels bellcrank colorful self adhesive markingsqp line Famous Fighters World War II designed use Cox Black Widow engine See products favorite hobby retailer todayl Famous Fighters World War II Models Available #258-Zero *259-Corsairshown #260-Thunderbolt #261 -FockeWuif Midwest Products Co. Inc 4005 Indiana St PO Box 364 Hobart IN 46342 219942-1134 FAX 219 947-23471 992 Midwest Producta CoInc ......... 8055279114 RIC GOODIES 1805 581-5061 cHRAN ST STE 281 SIMI VLY cA 93065 ER & AIRPLANE KITS #3 0 SPANREG GENESIS69$4295 SPEC 2-3 CH RADIO$35 75** STABLE FLYING WING GLIDER FOR HAND LAUNCH HI-START OR CLIFF SOARING MISPAN 100 SQIN 2-3 CH RADIO 06 020 GAS POWERED EASY TO BUILD & FLY DESIGNED FOR MICRO RADIO EQUIPMENT REG $20SSPEC $1885** ERTABLENEW OLD-TIMER RUBBER ROG OR ROW 6 DIE CUT BALSAPLANS INSTRUCTIONS TISSUE CANOPY AND RUBBER MOTOR REG $2995 SPEC $2695** 0 6 PRAIRIE BIRD 50 05 ELECTRIC 0 423 SQIN R/C TRAINER ANYONE CAN BUILD & FLYI $53 95SPEC $4860* SHIPPING INCLUDED IN CONT USA es Cash Cards 6% 0 Sales Tax Cat $1 USA $3 Foreign July1993 129
Edition: Model Aviation - 1993/07
Page Numbers: 26, 27, 28, 29, 30, 38, 129
HUMBUG 91 OLD-TIMER Nostalgia events competitive models have grown point rival corresponding contemporary events popularity Control Line Stunt no exception trend attraction old-time pre 1952 stunt planes unique personalities since typically offer performance presentday contest models Some Nostalgia stunters designs 25 years old exhibit performance equal greater present-day models Such case Humbug flapless 19-powered Humbug conceived 1966 Bill Netzeband clearly radical Revised version 1966 design Nostalgia Stunt flying features nonlinear control system U Robert Baron departure designs period Though approximately same wing area its competition Humbug used engine half size flapped stunters day attack pattern vengeance using full 70 feet line event allows Since flown days muffled engine too anemic acceptable performance high-revving Veco 19 produced earsplitting noise turning 8 x 5 prop about 12000 rpm Humbug never galned much acceptance stunt community becauseof its deviant appearance noisy engine example plane scored highest flying points two Nationals events finished out running due low static points 40 points available time Clearly performance package lacking fact fellow modeler said good-looking Humbug would oxymoron thought would interesting revisit unusual plane see flew after updating modem engine revised control system some structural improve ments new version equipped withan OS 28a muffler nonlinear control system carbon fiber wing spars has resulted plane silly Thats righta plane makes giggle updated power plant Humbug 91 can easily consecutive vertical square eights followed consecutive hourglasses After flying plane began wonder what would have happened stunt per formance rather package ruled roost last 25 years modifications spirit Nostalgia Stunt flying has maintained appearance original essentially unchanged Aside slight change nose length accommodate added weight muffler minor reduction rudder height outward appearance indistinguishable original except avid aficionados Critical changes structure control system power plant have incorporated modifica tions improve Humbugs performance life changing its fundamental character first change upgrading power plant easy engines have come market last 20 years substantial increases horsepower due Schnuerle porting better metallurgy closer manufacturing tolerances Schnuerle-type engine partic ularly suited Humbug design requirement constant high rpm rather traditional two- four-cycle run normally used Stunt An OS 28 used because its excellent construction twin ball bearings light weight engine comes effective muffler significant back pressure stock muffler power significantly greater original Clarence Lee-modified Veco 19 proved excellent selection OS readily turns 91/2-inch prop well enough result same fivesecond lap times original 26 Model Aviation 4Robert Baron Humbug 91 1966 version used Veco 19 power model uses muffled OS 32 Profile view shows tricycle landing gear Humbug 91 uses modern construction techniques retains appearance original engine has superseded OS 32 slightly heavier because fins cylinder larger otherwise very similar 32 turns prop es greater diameter old Veco 19 could resulting much thrust during maneuvers counts enables model corner harder original main taining sufficient speed clean exit tank set up run either conventional vent uniflo muffler pressure best runs obtained using uniflo no muffler pressure engine set just below maximum power runs hard two-cycle entire flight Fuel 10% nitro inlet diameter 250 inches muffler exhaust opening enlarged stock diameter 250 inches 270 inches 010 head gasket used addition stock gasket T greatest potential improvement after two decades progress change construction techniques did see compelling need change some structure main spar particular also assembly sequence used second time around almost completely reverse original main structural problem previous Humbugs severe cornering loads fatigued broke wood wing spar after few hundred flights performance plane degenerated Part problem spars carried through original models center section also suspected wood fatigue particularly since MonoKote used place paint paint adds substantial amount strength wood new version unidirectionai carbon fiber glued opposite sides -inch-square spars carried through center joined two pieces -inch square spar carbon fiber does bond particularly well balsa compression carbon fiber peels away under relatively little load bonding carbon fiber opposite sides side always tension minimizes amount spar can deflect Using technique rela tively low peel strength carbonfiber-to-balsa bond circumvented essence spar becomes I-beam two spars joined vertical shear webs entire structure becomes extremely stiff torsional strength wing nor significantly improved use carbon fiber spars does appear serious problem Im sure however additional torsional stiffness would improve stability wind tried use carbon tows running 450 angles between ribs develop torsional stiffness could get sufficiently reliable bond between balsa carbon fiber sheeting ribs able transmit loads fibers tried various brands cyanoacrylate CyA glues acceler ators success Bonding unidi rectional fibers epoxy throughout wing frame too tedious abandoned further attempts incor porate carbon fiber structure fter addressing structural problems original Humbug finding suitable modern power plant/muffler combination next challenge control system by-product exceptional performance original plane its control sensitivity level flight round maneuvers necessitated hours practice stability problemthe Humbug stable control inputs necessary level flight round maneuvers subtle hard make minor corrections desired control system slowed inputs low control deflections less 100 allowed full control needed squares Such system designed Bill Netzeband 10 years ago incorporated revolutionary /2A stunter called Barecat Bill found unless such system incorporated Humbug-type model airplanes performance would always have backed off because limitations imposed need fly level still able perform accurate round maneuvers nonlinear system analogous variable-ratio steering automobile results dramatic improvement ability fly level execute round maneuvers sacrificing planes ultimate performance square 30% increase speed control system extremes travel results corresponding 30% loss mechanical advantage means unless control forces kept light through aerodynamic balancing small moving surfaces system will unable generate enough torque full travel controls Such case conventional flapped stunterthe high binge moments required actuate flaps too much control system handle important remember control line system limited force available force limited line tension generated centrifugal force plane Once July1993 27 Fuselage cut near airfoils high point allow stabilizer installation CG adjustment nose section ot iuseiage used spacer locate slotted center wing ribs Wing spars LE TE sheeting cap strips some shear webs have installed point Belicrank mount nonlinear control system installed below rib centerline transfer arm clearance -inch sheet balsa stabilizer covered prior installation slotted attachment points control deflection demands exceed can generated line tension no additional deflection hence lift can obtained system requires careful fitting installation way accurately establish critical slot hole locations using millthe tolerances too demanding hand work Note particularly important system neutral position elevator neutral up down control response will significantly different addition length control horn elevator does simply change sensitivity handle system length elevator control horn determines maximum travel elevator determines extent nonlinear aspects system will observed flight properties airplane different conven tional system elevator horn length changes relationship between handle movement control deflection standpoint control sensitivity changing handle width conventional system will have effect identical changing horn length Because critical nature horn length relation rest control system slot machined horn effective length made infinitely adjustable over anticipated range adjusting horn length maximum travel elevator changed until cornering ability associated speed loss through corner liking handle width altered adjust sensitivity plane adjusting done after center gravity CG positioned per drawings simplicity conventional control system shown plans can substituted will some loss performance reasons stated above CONSTRUCTION fuselage made first since its exact width needed accurately locate center ribs Notice fuselage made piece would conventional plane cut two near high point wing necessary install aft fuselage around stabilizer attached before fuselage added allow nose length altered adjust center gravity construction nose can sawed off center still made fit wing aft body Depending engine/muffler combination used CU can altered adjusting nose length minimizes ballast requirements bottom block should glued permanently top block should tack-glued removal installing aft fuselage around stabilizer Note cowling hold-down consists two screws front tie blind nuts located 3A2 plywood nm two screws side body tie tabs cowling reason tabs no room conventional attachment point rear cowling since tank vents landing gear mount tank installation would interfere bottom portion fuselage forward fuselage break /8 Lite Ply grain running fore aft provide nose gear mount Under neath plywood l/ balsa grain running across fuselage adds significant stiffness bottom very little weight increase Blind nuts used conjunction nylon clips fasten nose gear One-eighth-inch aluminum plates used under engine prevent denting bearers engine bolted Once fuselage complete wing construction can started ribs made placing thirteen 342-inch sheets between 1A6 plywood templates drilling precise 3/s-inchdiameter holes installing brass tube hole prior carving rib stacks down templates holes ribs best cut using drill press sharpened piece 3/ brass tubing conventional drill bit will produce very poor quality hole drilling through stack balsa ribs marked will oriented jig bars same way during carving process cancels out error introduced jig alignment holes exactly centerline ribs After ribs made innermost outermost ribs traced cut -inch sheet balsa two ribs need made wider facilitate construction provide additional strength ribs slid onto jig bars use jig bars demon strated years ago Al Rabe far away accurate way construct built-up wing does work exceptionally well does increase construction time actually makes wing go together very easily Now should evident fuselage constructed first two -inch-sheet center ribs must located exact fuselage width since will important glue joint attach fuselage wing Use fuselage nose portion 28 Model Aviation covering slotted same manner stabi lizer receive rear fuselage section CG position determined pinning nose section place temporarily attaching hardware Incidence meter level used ensure thrustline wing centerline parallel Jig attaches engine mounts supports model comfortable heiaht durina finishina match wing color fuselage finished automotive lacquer over dope tissue talc Full Size Plans AvailableSee Page 184 -r CONVENTIONAL MELLORANE RUTFINL11 - IWINO HUMBUG 91 spacer locate center ribs prior attaching trailing edge sheeting leading edge spars Note slots center ribs bellcrank platform different depending control system used After trailing edge sheeting leading edge spars place landing gear mounts leading edge sheeting installed Tilt assembly edge run CyA glue down rib/sheet joint sure joints secure Install vertical shear webs position jig bars will allow glue shear webs between trailing edge planking Install -inch-wide cap strips ribs lightly block sand wing point structure relatively rigid stable alignment bars can removed best done attaching drill motor bars slowly spinning pulled structure Install remainder vertical shear webs blocked jig bars install belicrank mount controls can now added conventional bellcrank system used belicrank mount can installed centerline ribs non linear system used bellcrank mount must lowered allow height required transfer arm Complete wing installing pushrod wing tips wing tip box center section planking wing tip unusual centerline leadout guide installed 4 inch below centerline wing compensate vertical center gravity being below wing center line because weight engine landing gear guide location determined empirically hanging plane leadouts trying different locations sighting against plumb bob until proper position determined Cut window top center section planking completed wing neutral position bellcrank can seen will important stabilizer/elevator installed wing can now covered MonoKote July1993 29 tIIfl Type Nostalgia CL Stunt Wingspan 561/2 inches Recommended engine size type 05 32 muffler Type construction Built-up Type of covering/finish recommended MonoKote wing stabilizer booms automotive lacquer over tissue talc dope fuselage After final trim applied clear acrylic enamel used complete fuelproofing Highly modified Zinger 10 x 5 prop has worked best Humbua 91 Full details text Nose length rudder height visible differences between Humbug 91 original CENTURY JET MODELS INC 8 Martha Ct Sumter SC 29150 803 775-6491 RETRACT SELECTOR SPEED CONTROL VALVE 8305 Regency Woods Way Louisville KY 40220 502 491-4114 Four Infinite Adjustment Screws 2 Up 2 Down Compatible air system Dim 3/8 xls 1-1/4 $2495 Wt 15 oz Semi & Deluxe Ducted Fan Jet Kits Eposy fiberglass fuselage canopy foam wings plans instructions Intake/Exhaust System euc F-i 00 F-100 Hun basic kit $18999 1/8 Scale 50 Removable Wings Length 63 Sport Hawk MK II basic kit $18988 e P&H Easy buildl Removable wing Length 59 F-105 Thunderchief basic kit $23900 e P&H Length 73 77-91 Engine No Cheater Hole F-4 Phantom basic kit $59900 HEW 1/7 Scale Twin Engine Aileron/Spoiler Config Length 90 Removable 61 Wings LE/TE flaps Deluse kit DC wood I/B pylons CF kit plus morel Landing gear tires brakes available FLY THE F-100 SUPER SABRE FROM COMPARE OUR RETRACTS TO THEIRS Stainless Struts cut FREEl Stainless Torque Linksl Different strut configurations * 1 Year Limited Warranty GIANT MAIN RETRACTS STANDARD OR 900 ROTAl 30-50 lb aircraft 2 sets 1 Standard 900 minutes 7Q0 1100 retract angle Over-center lock down Nose gear available $27500 pair Wt 15 lbs Complete Air System Axle Installed Parts Service 30 Day Refund SCALE MAIN RETRACTS STANDARD OR 900 ROTATE Fits PICA Skys F-Si 1/5 Yellow A/C Ziroli Bud Nosen plus Choice 91 Plyon Winners Handles 20-25 lb aircraft 8497 retract angle Positive lock up lock down Optional wire struts Nose gear available $19900 pair Wt 22 oz NEW 1/5 SCALE P-Si & SPITFIRE products proudly MADE IN THE USAI TIRED OF DRAGGING YOUR WING TIPS ON ThE GROUND. WV DUCTS FOR VIOJETT OR DYNAMAX PLEASE SPECIFY VERY COMPLETE KIT F100....... $550 VIDEO TAPE MANUAL $20 F100 DEMO TAPE .$10 FREE PITOT POWER$8SSH OFFSET DOOR HINGES B FOR $8 CALL FOR QUANTITY PRICES USHER ENTERPRISES INC 1017 SE FRONTAGE RD BOX 511 NORTH PLAINS OR 97133 503647 0015 booms made next sandwiching length Y32 plywood between two pieces 3/ts balsa makes extremely stiff light boom t/2 ounce Mono Kote covering wrapped around edge joins wing Cut away just enough effect good bond wing Cut away just enough MonoKote wing good glue jointso no bare wood exposed outboard booms booms glued wing using slow-curing epoxy gives time accurately align well wipe away excess glue alcohol thinner stabilizer elevator made U -inch sheet balsa covered MonoKote prior installation cutting slots covering per booms stabilizer now glued booms taking care locate accurately relative wing Note body glued time placed wing reference stabilizer alignment Now look window wing center section planking place bellcrank neutral position Tape pushrod wing cannot move pushrod attached elevator horn elevator temporarily held place hinges glue hinges time clevis adjusted until elevator neutral pushrodlbellcrank maintained neutral position point release tape pushrod check action controls Remove top block rear portion fuselage install aft body around stabilizer taking care put load stabilizer Cut slots MonoKote attach rear fuselage wing Glue top block cut slot fin At this point nose portion use age can pinned place center gravity can determined installing hardware plane nose heavy fuselage can cut center section shortened until proper center gravity approximately t/8 inch front position shown plans weight fillets paint will shift center gravity slightly aft entire plane painted rather covered MonoKote will have guess weight paint its effect center gravity determine nose length will require minimum ballast Glue fuselage slow-curing epoxy using Robart incidence meter conjunction bubble level ensure thrustline parallel wing centerline Glass nose using 3¼-ounce cloth epoxy fin can permanently glued fuselage canopy added complete framing aircraft fuselage can painted per favorite finishing technique model standard dope tissue talc finish used fillthe grain Since commercial modeling dopes good match Continued page 38 30 Model Aviation t day Saturday OUTLAWFAI COM BAT FIrst match starts 1000 am Saturday Entry Fee $700Open Juniors $500 Sponsored Betty Fox Doc Passen Awards prizes third place Special prize highest place Junior Second day Sunday SUPER-SLOW COMBAT Entry Fee $1000Open Juniors $500 Sponsored FOX Manufacturing DoCs Generix Controline Kits Doc Passen Contest Director information call Write PO Box 111 Jasonville IN 47438 Telephone 812 665-3723 2 days Control Line Combat Wood Hand Selected Fiberglass Cowl Complete Plans Parts Hand Cut Instruction Manual Photo Page order kits call 1-800-327-7198 catalog fine kits send $400Idaho Residents Add 5% State Sales Tax Gasoline fueled Produces 3 foot flame will power planes up 228 mph Designed FUN EASY build home shop about 8 hours using materials already have such aerosol spray can combustion chamber Only simple hand tools needed Both high performance jet engines FUN EASY build STEP BY STEP DETAILED FULL SIZE plan sets complete fuel ignition systems JOIN THE JET AGE sending $995 3hp plan set $1295 7hp plan set both sets $2000 JET ENGINE10241 Ridgewood El Paso Texas 79925 AFTER YOU DID ALL THE WORK WHY LET YOUR AIRPLANE DO ALL THE FLYING HumbuglBaron Continued page 30 white MonoKote used automotive lacquer After trim paint canopy can sealed Ditzler acrylic enamel completely fuel proof finish applying final clear coat recommended masking tape placed slightly outside fillet enamel can run around edge fillet seal edge use 3M fine line tape masking gives clean edge leaves no residue removed Remember pull tape off enamel still tacky prevent bonding tape plane allow enamel seal edge During finish workincluding doping applying paper fillets spraying maskingI use ajig attaches engine mounts suspends plane comfortable height Complete paint trim rudder elevator hinging landing gear installation plane held jig FLYING AND TRIMMING Since Humbug has no flaps easier adjust conventional stunter First install ballast required position center gravity shown plans stability standpoint plane will tolerate aft center gravity line tension positive under varied condi tions center gravity aft position shown plans Set leadouts line shown plans Test flights should short lines 62-64 feet x 015 safety Once model trimmed out 65-68 feet optimum Place approximately e weight tip box Adjust elevator horn provide 250 travel direction started four-inch-wide handle As stunters prop selection criti cal amazing little piece wood can affect flight performance prefer wood propsthey readily modified light weight keeps precession minimum get stunt plane pitch gauge must can make blades accurate pitch gauge can also determine exactly way need adjust pitch obtain desired performance general lower pitch greater vertical capability provided engine can turn prop fast enough give adequate airspeed Increasing pitch will increase airspeed will also increase tendency whip up windy conditions Increased diameter also increases vertical capability cost increased whip-up wind Changing blade shape alters power requirements may cause corresponding change airspeed thrust Finding trade-off between diameter pitch blade shape challenge Humbug 91 can save some time giving dimensions best prop date Start Zinger Continued page 129 38 Model Aviation 4PUGNACIOUS PUSSY CAT 1/4 scale Gee Bee Model Y 9017 lbs 3 7 HP PULSE JET ENGINES AVAILABLE BUILD & FLY THE miniMAX VflI IRFI Fl ampion ana- uomputer uesigneoMss serve Urand unampion ultralightPart 103 UltralightEasy construction 1989 Sun-N-Pun Fly-InWood construction TEAM INC 10790-MA Ivy Bluff Rd Bradyville TN 37026615-765-5397 HumbuglBaron Continued page 38 10 x 5 measured pitch 46 5 inches de-pitch true 40 inches stations Next cut diameter 91/2 inches using dial calipers exactly measure blades length carve sweep leading edge starting approximately inch tip ending tip diameter about 1/ inch Balance blade minimize vibration Carefully check flying site presence small rocks tricycle landing gear thin prop turning high rpm can easily broken leading shaft run can damage airframe Set engine hard two-cycle clearly off maximum power 91/2 x 4 prop lap times should 4 5 seconds Check wings level both upright inverted flight wing high steam wing over kettle boiling water until model flies level both upright inverted found wing obviously need steaming based initial flights warp readily detected sighting down trailing edge event steam wing direction indicated attitude plane level flight wing high both directions add tip weight low both ways remove weight Next make sure engine running same both attitudes Checking lap times both upright inverted good way determine tank needs shimming plane slower right-sideup inverted shim tank down until lap times way close equal Once above steps have completed final trimming matter adjusting control travel trade off cornering against loss airspeed adjusting handle width suit needs ended up 220 elevator travel Minor adjustments leadout rake can made adjusting up line improve inside maneuvers down line outside maneuvers Small changes prop diameter 1/s inch time will result tighter slower corners diameter decreased opposite effect diameter increased As high-performance vehicle very small adjustments have significant effects flight character istics 1/s-inch change leadout rake few mph change airspeed will readily noticed handle possible adjustments very wide range performance handling characteristics available flier Humbug will utilize trimming flying skills hand can trimmed fly like trainer other can trimmed deliver performance tax experienced pilot make choice ess Series U-Control Kits Beginners *0 06 wests new Success Series 049 U-Control kits perfect introduction building flying Featuring illustrated step-by-step Success Series construction manuals teach build paint fly models Kits include Micro-Cut Quality parts pre-formed wire parts wheels bellcrank colorful self adhesive markingsqp line Famous Fighters World War II designed use Cox Black Widow engine See products favorite hobby retailer todayl Famous Fighters World War II Models Available #258-Zero *259-Corsairshown #260-Thunderbolt #261 -FockeWuif Midwest Products Co. Inc 4005 Indiana St PO Box 364 Hobart IN 46342 219942-1134 FAX 219 947-23471 992 Midwest Producta CoInc ......... 8055279114 RIC GOODIES 1805 581-5061 cHRAN ST STE 281 SIMI VLY cA 93065 ER & AIRPLANE KITS #3 0 SPANREG GENESIS69$4295 SPEC 2-3 CH RADIO$35 75** STABLE FLYING WING GLIDER FOR HAND LAUNCH HI-START OR CLIFF SOARING MISPAN 100 SQIN 2-3 CH RADIO 06 020 GAS POWERED EASY TO BUILD & FLY DESIGNED FOR MICRO RADIO EQUIPMENT REG $20SSPEC $1885** ERTABLENEW OLD-TIMER RUBBER ROG OR ROW 6 DIE CUT BALSAPLANS INSTRUCTIONS TISSUE CANOPY AND RUBBER MOTOR REG $2995 SPEC $2695** 0 6 PRAIRIE BIRD 50 05 ELECTRIC 0 423 SQIN R/C TRAINER ANYONE CAN BUILD & FLYI $53 95SPEC $4860* SHIPPING INCLUDED IN CONT USA es Cash Cards 6% 0 Sales Tax Cat $1 USA $3 Foreign July1993 129
Edition: Model Aviation - 1993/07
Page Numbers: 26, 27, 28, 29, 30, 38, 129
HUMBUG 91 OLD-TIMER Nostalgia events competitive models have grown point rival corresponding contemporary events popularity Control Line Stunt no exception trend attraction old-time pre 1952 stunt planes unique personalities since typically offer performance presentday contest models Some Nostalgia stunters designs 25 years old exhibit performance equal greater present-day models Such case Humbug flapless 19-powered Humbug conceived 1966 Bill Netzeband clearly radical Revised version 1966 design Nostalgia Stunt flying features nonlinear control system U Robert Baron departure designs period Though approximately same wing area its competition Humbug used engine half size flapped stunters day attack pattern vengeance using full 70 feet line event allows Since flown days muffled engine too anemic acceptable performance high-revving Veco 19 produced earsplitting noise turning 8 x 5 prop about 12000 rpm Humbug never galned much acceptance stunt community becauseof its deviant appearance noisy engine example plane scored highest flying points two Nationals events finished out running due low static points 40 points available time Clearly performance package lacking fact fellow modeler said good-looking Humbug would oxymoron thought would interesting revisit unusual plane see flew after updating modem engine revised control system some structural improve ments new version equipped withan OS 28a muffler nonlinear control system carbon fiber wing spars has resulted plane silly Thats righta plane makes giggle updated power plant Humbug 91 can easily consecutive vertical square eights followed consecutive hourglasses After flying plane began wonder what would have happened stunt per formance rather package ruled roost last 25 years modifications spirit Nostalgia Stunt flying has maintained appearance original essentially unchanged Aside slight change nose length accommodate added weight muffler minor reduction rudder height outward appearance indistinguishable original except avid aficionados Critical changes structure control system power plant have incorporated modifica tions improve Humbugs performance life changing its fundamental character first change upgrading power plant easy engines have come market last 20 years substantial increases horsepower due Schnuerle porting better metallurgy closer manufacturing tolerances Schnuerle-type engine partic ularly suited Humbug design requirement constant high rpm rather traditional two- four-cycle run normally used Stunt An OS 28 used because its excellent construction twin ball bearings light weight engine comes effective muffler significant back pressure stock muffler power significantly greater original Clarence Lee-modified Veco 19 proved excellent selection OS readily turns 91/2-inch prop well enough result same fivesecond lap times original 26 Model Aviation 4Robert Baron Humbug 91 1966 version used Veco 19 power model uses muffled OS 32 Profile view shows tricycle landing gear Humbug 91 uses modern construction techniques retains appearance original engine has superseded OS 32 slightly heavier because fins cylinder larger otherwise very similar 32 turns prop es greater diameter old Veco 19 could resulting much thrust during maneuvers counts enables model corner harder original main taining sufficient speed clean exit tank set up run either conventional vent uniflo muffler pressure best runs obtained using uniflo no muffler pressure engine set just below maximum power runs hard two-cycle entire flight Fuel 10% nitro inlet diameter 250 inches muffler exhaust opening enlarged stock diameter 250 inches 270 inches 010 head gasket used addition stock gasket T greatest potential improvement after two decades progress change construction techniques did see compelling need change some structure main spar particular also assembly sequence used second time around almost completely reverse original main structural problem previous Humbugs severe cornering loads fatigued broke wood wing spar after few hundred flights performance plane degenerated Part problem spars carried through original models center section also suspected wood fatigue particularly since MonoKote used place paint paint adds substantial amount strength wood new version unidirectionai carbon fiber glued opposite sides -inch-square spars carried through center joined two pieces -inch square spar carbon fiber does bond particularly well balsa compression carbon fiber peels away under relatively little load bonding carbon fiber opposite sides side always tension minimizes amount spar can deflect Using technique rela tively low peel strength carbonfiber-to-balsa bond circumvented essence spar becomes I-beam two spars joined vertical shear webs entire structure becomes extremely stiff torsional strength wing nor significantly improved use carbon fiber spars does appear serious problem Im sure however additional torsional stiffness would improve stability wind tried use carbon tows running 450 angles between ribs develop torsional stiffness could get sufficiently reliable bond between balsa carbon fiber sheeting ribs able transmit loads fibers tried various brands cyanoacrylate CyA glues acceler ators success Bonding unidi rectional fibers epoxy throughout wing frame too tedious abandoned further attempts incor porate carbon fiber structure fter addressing structural problems original Humbug finding suitable modern power plant/muffler combination next challenge control system by-product exceptional performance original plane its control sensitivity level flight round maneuvers necessitated hours practice stability problemthe Humbug stable control inputs necessary level flight round maneuvers subtle hard make minor corrections desired control system slowed inputs low control deflections less 100 allowed full control needed squares Such system designed Bill Netzeband 10 years ago incorporated revolutionary /2A stunter called Barecat Bill found unless such system incorporated Humbug-type model airplanes performance would always have backed off because limitations imposed need fly level still able perform accurate round maneuvers nonlinear system analogous variable-ratio steering automobile results dramatic improvement ability fly level execute round maneuvers sacrificing planes ultimate performance square 30% increase speed control system extremes travel results corresponding 30% loss mechanical advantage means unless control forces kept light through aerodynamic balancing small moving surfaces system will unable generate enough torque full travel controls Such case conventional flapped stunterthe high binge moments required actuate flaps too much control system handle important remember control line system limited force available force limited line tension generated centrifugal force plane Once July1993 27 Fuselage cut near airfoils high point allow stabilizer installation CG adjustment nose section ot iuseiage used spacer locate slotted center wing ribs Wing spars LE TE sheeting cap strips some shear webs have installed point Belicrank mount nonlinear control system installed below rib centerline transfer arm clearance -inch sheet balsa stabilizer covered prior installation slotted attachment points control deflection demands exceed can generated line tension no additional deflection hence lift can obtained system requires careful fitting installation way accurately establish critical slot hole locations using millthe tolerances too demanding hand work Note particularly important system neutral position elevator neutral up down control response will significantly different addition length control horn elevator does simply change sensitivity handle system length elevator control horn determines maximum travel elevator determines extent nonlinear aspects system will observed flight properties airplane different conven tional system elevator horn length changes relationship between handle movement control deflection standpoint control sensitivity changing handle width conventional system will have effect identical changing horn length Because critical nature horn length relation rest control system slot machined horn effective length made infinitely adjustable over anticipated range adjusting horn length maximum travel elevator changed until cornering ability associated speed loss through corner liking handle width altered adjust sensitivity plane adjusting done after center gravity CG positioned per drawings simplicity conventional control system shown plans can substituted will some loss performance reasons stated above CONSTRUCTION fuselage made first since its exact width needed accurately locate center ribs Notice fuselage made piece would conventional plane cut two near high point wing necessary install aft fuselage around stabilizer attached before fuselage added allow nose length altered adjust center gravity construction nose can sawed off center still made fit wing aft body Depending engine/muffler combination used CU can altered adjusting nose length minimizes ballast requirements bottom block should glued permanently top block should tack-glued removal installing aft fuselage around stabilizer Note cowling hold-down consists two screws front tie blind nuts located 3A2 plywood nm two screws side body tie tabs cowling reason tabs no room conventional attachment point rear cowling since tank vents landing gear mount tank installation would interfere bottom portion fuselage forward fuselage break /8 Lite Ply grain running fore aft provide nose gear mount Under neath plywood l/ balsa grain running across fuselage adds significant stiffness bottom very little weight increase Blind nuts used conjunction nylon clips fasten nose gear One-eighth-inch aluminum plates used under engine prevent denting bearers engine bolted Once fuselage complete wing construction can started ribs made placing thirteen 342-inch sheets between 1A6 plywood templates drilling precise 3/s-inchdiameter holes installing brass tube hole prior carving rib stacks down templates holes ribs best cut using drill press sharpened piece 3/ brass tubing conventional drill bit will produce very poor quality hole drilling through stack balsa ribs marked will oriented jig bars same way during carving process cancels out error introduced jig alignment holes exactly centerline ribs After ribs made innermost outermost ribs traced cut -inch sheet balsa two ribs need made wider facilitate construction provide additional strength ribs slid onto jig bars use jig bars demon strated years ago Al Rabe far away accurate way construct built-up wing does work exceptionally well does increase construction time actually makes wing go together very easily Now should evident fuselage constructed first two -inch-sheet center ribs must located exact fuselage width since will important glue joint attach fuselage wing Use fuselage nose portion 28 Model Aviation covering slotted same manner stabi lizer receive rear fuselage section CG position determined pinning nose section place temporarily attaching hardware Incidence meter level used ensure thrustline wing centerline parallel Jig attaches engine mounts supports model comfortable heiaht durina finishina match wing color fuselage finished automotive lacquer over dope tissue talc Full Size Plans AvailableSee Page 184 -r CONVENTIONAL MELLORANE RUTFINL11 - IWINO HUMBUG 91 spacer locate center ribs prior attaching trailing edge sheeting leading edge spars Note slots center ribs bellcrank platform different depending control system used After trailing edge sheeting leading edge spars place landing gear mounts leading edge sheeting installed Tilt assembly edge run CyA glue down rib/sheet joint sure joints secure Install vertical shear webs position jig bars will allow glue shear webs between trailing edge planking Install -inch-wide cap strips ribs lightly block sand wing point structure relatively rigid stable alignment bars can removed best done attaching drill motor bars slowly spinning pulled structure Install remainder vertical shear webs blocked jig bars install belicrank mount controls can now added conventional bellcrank system used belicrank mount can installed centerline ribs non linear system used bellcrank mount must lowered allow height required transfer arm Complete wing installing pushrod wing tips wing tip box center section planking wing tip unusual centerline leadout guide installed 4 inch below centerline wing compensate vertical center gravity being below wing center line because weight engine landing gear guide location determined empirically hanging plane leadouts trying different locations sighting against plumb bob until proper position determined Cut window top center section planking completed wing neutral position bellcrank can seen will important stabilizer/elevator installed wing can now covered MonoKote July1993 29 tIIfl Type Nostalgia CL Stunt Wingspan 561/2 inches Recommended engine size type 05 32 muffler Type construction Built-up Type of covering/finish recommended MonoKote wing stabilizer booms automotive lacquer over tissue talc dope fuselage After final trim applied clear acrylic enamel used complete fuelproofing Highly modified Zinger 10 x 5 prop has worked best Humbua 91 Full details text Nose length rudder height visible differences between Humbug 91 original CENTURY JET MODELS INC 8 Martha Ct Sumter SC 29150 803 775-6491 RETRACT SELECTOR SPEED CONTROL VALVE 8305 Regency Woods Way Louisville KY 40220 502 491-4114 Four Infinite Adjustment Screws 2 Up 2 Down Compatible air system Dim 3/8 xls 1-1/4 $2495 Wt 15 oz Semi & Deluxe Ducted Fan Jet Kits Eposy fiberglass fuselage canopy foam wings plans instructions Intake/Exhaust System euc F-i 00 F-100 Hun basic kit $18999 1/8 Scale 50 Removable Wings Length 63 Sport Hawk MK II basic kit $18988 e P&H Easy buildl Removable wing Length 59 F-105 Thunderchief basic kit $23900 e P&H Length 73 77-91 Engine No Cheater Hole F-4 Phantom basic kit $59900 HEW 1/7 Scale Twin Engine Aileron/Spoiler Config Length 90 Removable 61 Wings LE/TE flaps Deluse kit DC wood I/B pylons CF kit plus morel Landing gear tires brakes available FLY THE F-100 SUPER SABRE FROM COMPARE OUR RETRACTS TO THEIRS Stainless Struts cut FREEl Stainless Torque Linksl Different strut configurations * 1 Year Limited Warranty GIANT MAIN RETRACTS STANDARD OR 900 ROTAl 30-50 lb aircraft 2 sets 1 Standard 900 minutes 7Q0 1100 retract angle Over-center lock down Nose gear available $27500 pair Wt 15 lbs Complete Air System Axle Installed Parts Service 30 Day Refund SCALE MAIN RETRACTS STANDARD OR 900 ROTATE Fits PICA Skys F-Si 1/5 Yellow A/C Ziroli Bud Nosen plus Choice 91 Plyon Winners Handles 20-25 lb aircraft 8497 retract angle Positive lock up lock down Optional wire struts Nose gear available $19900 pair Wt 22 oz NEW 1/5 SCALE P-Si & SPITFIRE products proudly MADE IN THE USAI TIRED OF DRAGGING YOUR WING TIPS ON ThE GROUND. WV DUCTS FOR VIOJETT OR DYNAMAX PLEASE SPECIFY VERY COMPLETE KIT F100....... $550 VIDEO TAPE MANUAL $20 F100 DEMO TAPE .$10 FREE PITOT POWER$8SSH OFFSET DOOR HINGES B FOR $8 CALL FOR QUANTITY PRICES USHER ENTERPRISES INC 1017 SE FRONTAGE RD BOX 511 NORTH PLAINS OR 97133 503647 0015 booms made next sandwiching length Y32 plywood between two pieces 3/ts balsa makes extremely stiff light boom t/2 ounce Mono Kote covering wrapped around edge joins wing Cut away just enough effect good bond wing Cut away just enough MonoKote wing good glue jointso no bare wood exposed outboard booms booms glued wing using slow-curing epoxy gives time accurately align well wipe away excess glue alcohol thinner stabilizer elevator made U -inch sheet balsa covered MonoKote prior installation cutting slots covering per booms stabilizer now glued booms taking care locate accurately relative wing Note body glued time placed wing reference stabilizer alignment Now look window wing center section planking place bellcrank neutral position Tape pushrod wing cannot move pushrod attached elevator horn elevator temporarily held place hinges glue hinges time clevis adjusted until elevator neutral pushrodlbellcrank maintained neutral position point release tape pushrod check action controls Remove top block rear portion fuselage install aft body around stabilizer taking care put load stabilizer Cut slots MonoKote attach rear fuselage wing Glue top block cut slot fin At this point nose portion use age can pinned place center gravity can determined installing hardware plane nose heavy fuselage can cut center section shortened until proper center gravity approximately t/8 inch front position shown plans weight fillets paint will shift center gravity slightly aft entire plane painted rather covered MonoKote will have guess weight paint its effect center gravity determine nose length will require minimum ballast Glue fuselage slow-curing epoxy using Robart incidence meter conjunction bubble level ensure thrustline parallel wing centerline Glass nose using 3¼-ounce cloth epoxy fin can permanently glued fuselage canopy added complete framing aircraft fuselage can painted per favorite finishing technique model standard dope tissue talc finish used fillthe grain Since commercial modeling dopes good match Continued page 38 30 Model Aviation t day Saturday OUTLAWFAI COM BAT FIrst match starts 1000 am Saturday Entry Fee $700Open Juniors $500 Sponsored Betty Fox Doc Passen Awards prizes third place Special prize highest place Junior Second day Sunday SUPER-SLOW COMBAT Entry Fee $1000Open Juniors $500 Sponsored FOX Manufacturing DoCs Generix Controline Kits Doc Passen Contest Director information call Write PO Box 111 Jasonville IN 47438 Telephone 812 665-3723 2 days Control Line Combat Wood Hand Selected Fiberglass Cowl Complete Plans Parts Hand Cut Instruction Manual Photo Page order kits call 1-800-327-7198 catalog fine kits send $400Idaho Residents Add 5% State Sales Tax Gasoline fueled Produces 3 foot flame will power planes up 228 mph Designed FUN EASY build home shop about 8 hours using materials already have such aerosol spray can combustion chamber Only simple hand tools needed Both high performance jet engines FUN EASY build STEP BY STEP DETAILED FULL SIZE plan sets complete fuel ignition systems JOIN THE JET AGE sending $995 3hp plan set $1295 7hp plan set both sets $2000 JET ENGINE10241 Ridgewood El Paso Texas 79925 AFTER YOU DID ALL THE WORK WHY LET YOUR AIRPLANE DO ALL THE FLYING HumbuglBaron Continued page 30 white MonoKote used automotive lacquer After trim paint canopy can sealed Ditzler acrylic enamel completely fuel proof finish applying final clear coat recommended masking tape placed slightly outside fillet enamel can run around edge fillet seal edge use 3M fine line tape masking gives clean edge leaves no residue removed Remember pull tape off enamel still tacky prevent bonding tape plane allow enamel seal edge During finish workincluding doping applying paper fillets spraying maskingI use ajig attaches engine mounts suspends plane comfortable height Complete paint trim rudder elevator hinging landing gear installation plane held jig FLYING AND TRIMMING Since Humbug has no flaps easier adjust conventional stunter First install ballast required position center gravity shown plans stability standpoint plane will tolerate aft center gravity line tension positive under varied condi tions center gravity aft position shown plans Set leadouts line shown plans Test flights should short lines 62-64 feet x 015 safety Once model trimmed out 65-68 feet optimum Place approximately e weight tip box Adjust elevator horn provide 250 travel direction started four-inch-wide handle As stunters prop selection criti cal amazing little piece wood can affect flight performance prefer wood propsthey readily modified light weight keeps precession minimum get stunt plane pitch gauge must can make blades accurate pitch gauge can also determine exactly way need adjust pitch obtain desired performance general lower pitch greater vertical capability provided engine can turn prop fast enough give adequate airspeed Increasing pitch will increase airspeed will also increase tendency whip up windy conditions Increased diameter also increases vertical capability cost increased whip-up wind Changing blade shape alters power requirements may cause corresponding change airspeed thrust Finding trade-off between diameter pitch blade shape challenge Humbug 91 can save some time giving dimensions best prop date Start Zinger Continued page 129 38 Model Aviation 4PUGNACIOUS PUSSY CAT 1/4 scale Gee Bee Model Y 9017 lbs 3 7 HP PULSE JET ENGINES AVAILABLE BUILD & FLY THE miniMAX VflI IRFI Fl ampion ana- uomputer uesigneoMss serve Urand unampion ultralightPart 103 UltralightEasy construction 1989 Sun-N-Pun Fly-InWood construction TEAM INC 10790-MA Ivy Bluff Rd Bradyville TN 37026615-765-5397 HumbuglBaron Continued page 38 10 x 5 measured pitch 46 5 inches de-pitch true 40 inches stations Next cut diameter 91/2 inches using dial calipers exactly measure blades length carve sweep leading edge starting approximately inch tip ending tip diameter about 1/ inch Balance blade minimize vibration Carefully check flying site presence small rocks tricycle landing gear thin prop turning high rpm can easily broken leading shaft run can damage airframe Set engine hard two-cycle clearly off maximum power 91/2 x 4 prop lap times should 4 5 seconds Check wings level both upright inverted flight wing high steam wing over kettle boiling water until model flies level both upright inverted found wing obviously need steaming based initial flights warp readily detected sighting down trailing edge event steam wing direction indicated attitude plane level flight wing high both directions add tip weight low both ways remove weight Next make sure engine running same both attitudes Checking lap times both upright inverted good way determine tank needs shimming plane slower right-sideup inverted shim tank down until lap times way close equal Once above steps have completed final trimming matter adjusting control travel trade off cornering against loss airspeed adjusting handle width suit needs ended up 220 elevator travel Minor adjustments leadout rake can made adjusting up line improve inside maneuvers down line outside maneuvers Small changes prop diameter 1/s inch time will result tighter slower corners diameter decreased opposite effect diameter increased As high-performance vehicle very small adjustments have significant effects flight character istics 1/s-inch change leadout rake few mph change airspeed will readily noticed handle possible adjustments very wide range performance handling characteristics available flier Humbug will utilize trimming flying skills hand can trimmed fly like trainer other can trimmed deliver performance tax experienced pilot make choice ess Series U-Control Kits Beginners *0 06 wests new Success Series 049 U-Control kits perfect introduction building flying Featuring illustrated step-by-step Success Series construction manuals teach build paint fly models Kits include Micro-Cut Quality parts pre-formed wire parts wheels bellcrank colorful self adhesive markingsqp line Famous Fighters World War II designed use Cox Black Widow engine See products favorite hobby retailer todayl Famous Fighters World War II Models Available #258-Zero *259-Corsairshown #260-Thunderbolt #261 -FockeWuif Midwest Products Co. Inc 4005 Indiana St PO Box 364 Hobart IN 46342 219942-1134 FAX 219 947-23471 992 Midwest Producta CoInc ......... 8055279114 RIC GOODIES 1805 581-5061 cHRAN ST STE 281 SIMI VLY cA 93065 ER & AIRPLANE KITS #3 0 SPANREG GENESIS69$4295 SPEC 2-3 CH RADIO$35 75** STABLE FLYING WING GLIDER FOR HAND LAUNCH HI-START OR CLIFF SOARING MISPAN 100 SQIN 2-3 CH RADIO 06 020 GAS POWERED EASY TO BUILD & FLY DESIGNED FOR MICRO RADIO EQUIPMENT REG $20SSPEC $1885** ERTABLENEW OLD-TIMER RUBBER ROG OR ROW 6 DIE CUT BALSAPLANS INSTRUCTIONS TISSUE CANOPY AND RUBBER MOTOR REG $2995 SPEC $2695** 0 6 PRAIRIE BIRD 50 05 ELECTRIC 0 423 SQIN R/C TRAINER ANYONE CAN BUILD & FLYI $53 95SPEC $4860* SHIPPING INCLUDED IN CONT USA es Cash Cards 6% 0 Sales Tax Cat $1 USA $3 Foreign July1993 129
Edition: Model Aviation - 1993/07
Page Numbers: 26, 27, 28, 29, 30, 38, 129
HUMBUG 91 OLD-TIMER Nostalgia events competitive models have grown point rival corresponding contemporary events popularity Control Line Stunt no exception trend attraction old-time pre 1952 stunt planes unique personalities since typically offer performance presentday contest models Some Nostalgia stunters designs 25 years old exhibit performance equal greater present-day models Such case Humbug flapless 19-powered Humbug conceived 1966 Bill Netzeband clearly radical Revised version 1966 design Nostalgia Stunt flying features nonlinear control system U Robert Baron departure designs period Though approximately same wing area its competition Humbug used engine half size flapped stunters day attack pattern vengeance using full 70 feet line event allows Since flown days muffled engine too anemic acceptable performance high-revving Veco 19 produced earsplitting noise turning 8 x 5 prop about 12000 rpm Humbug never galned much acceptance stunt community becauseof its deviant appearance noisy engine example plane scored highest flying points two Nationals events finished out running due low static points 40 points available time Clearly performance package lacking fact fellow modeler said good-looking Humbug would oxymoron thought would interesting revisit unusual plane see flew after updating modem engine revised control system some structural improve ments new version equipped withan OS 28a muffler nonlinear control system carbon fiber wing spars has resulted plane silly Thats righta plane makes giggle updated power plant Humbug 91 can easily consecutive vertical square eights followed consecutive hourglasses After flying plane began wonder what would have happened stunt per formance rather package ruled roost last 25 years modifications spirit Nostalgia Stunt flying has maintained appearance original essentially unchanged Aside slight change nose length accommodate added weight muffler minor reduction rudder height outward appearance indistinguishable original except avid aficionados Critical changes structure control system power plant have incorporated modifica tions improve Humbugs performance life changing its fundamental character first change upgrading power plant easy engines have come market last 20 years substantial increases horsepower due Schnuerle porting better metallurgy closer manufacturing tolerances Schnuerle-type engine partic ularly suited Humbug design requirement constant high rpm rather traditional two- four-cycle run normally used Stunt An OS 28 used because its excellent construction twin ball bearings light weight engine comes effective muffler significant back pressure stock muffler power significantly greater original Clarence Lee-modified Veco 19 proved excellent selection OS readily turns 91/2-inch prop well enough result same fivesecond lap times original 26 Model Aviation 4Robert Baron Humbug 91 1966 version used Veco 19 power model uses muffled OS 32 Profile view shows tricycle landing gear Humbug 91 uses modern construction techniques retains appearance original engine has superseded OS 32 slightly heavier because fins cylinder larger otherwise very similar 32 turns prop es greater diameter old Veco 19 could resulting much thrust during maneuvers counts enables model corner harder original main taining sufficient speed clean exit tank set up run either conventional vent uniflo muffler pressure best runs obtained using uniflo no muffler pressure engine set just below maximum power runs hard two-cycle entire flight Fuel 10% nitro inlet diameter 250 inches muffler exhaust opening enlarged stock diameter 250 inches 270 inches 010 head gasket used addition stock gasket T greatest potential improvement after two decades progress change construction techniques did see compelling need change some structure main spar particular also assembly sequence used second time around almost completely reverse original main structural problem previous Humbugs severe cornering loads fatigued broke wood wing spar after few hundred flights performance plane degenerated Part problem spars carried through original models center section also suspected wood fatigue particularly since MonoKote used place paint paint adds substantial amount strength wood new version unidirectionai carbon fiber glued opposite sides -inch-square spars carried through center joined two pieces -inch square spar carbon fiber does bond particularly well balsa compression carbon fiber peels away under relatively little load bonding carbon fiber opposite sides side always tension minimizes amount spar can deflect Using technique rela tively low peel strength carbonfiber-to-balsa bond circumvented essence spar becomes I-beam two spars joined vertical shear webs entire structure becomes extremely stiff torsional strength wing nor significantly improved use carbon fiber spars does appear serious problem Im sure however additional torsional stiffness would improve stability wind tried use carbon tows running 450 angles between ribs develop torsional stiffness could get sufficiently reliable bond between balsa carbon fiber sheeting ribs able transmit loads fibers tried various brands cyanoacrylate CyA glues acceler ators success Bonding unidi rectional fibers epoxy throughout wing frame too tedious abandoned further attempts incor porate carbon fiber structure fter addressing structural problems original Humbug finding suitable modern power plant/muffler combination next challenge control system by-product exceptional performance original plane its control sensitivity level flight round maneuvers necessitated hours practice stability problemthe Humbug stable control inputs necessary level flight round maneuvers subtle hard make minor corrections desired control system slowed inputs low control deflections less 100 allowed full control needed squares Such system designed Bill Netzeband 10 years ago incorporated revolutionary /2A stunter called Barecat Bill found unless such system incorporated Humbug-type model airplanes performance would always have backed off because limitations imposed need fly level still able perform accurate round maneuvers nonlinear system analogous variable-ratio steering automobile results dramatic improvement ability fly level execute round maneuvers sacrificing planes ultimate performance square 30% increase speed control system extremes travel results corresponding 30% loss mechanical advantage means unless control forces kept light through aerodynamic balancing small moving surfaces system will unable generate enough torque full travel controls Such case conventional flapped stunterthe high binge moments required actuate flaps too much control system handle important remember control line system limited force available force limited line tension generated centrifugal force plane Once July1993 27 Fuselage cut near airfoils high point allow stabilizer installation CG adjustment nose section ot iuseiage used spacer locate slotted center wing ribs Wing spars LE TE sheeting cap strips some shear webs have installed point Belicrank mount nonlinear control system installed below rib centerline transfer arm clearance -inch sheet balsa stabilizer covered prior installation slotted attachment points control deflection demands exceed can generated line tension no additional deflection hence lift can obtained system requires careful fitting installation way accurately establish critical slot hole locations using millthe tolerances too demanding hand work Note particularly important system neutral position elevator neutral up down control response will significantly different addition length control horn elevator does simply change sensitivity handle system length elevator control horn determines maximum travel elevator determines extent nonlinear aspects system will observed flight properties airplane different conven tional system elevator horn length changes relationship between handle movement control deflection standpoint control sensitivity changing handle width conventional system will have effect identical changing horn length Because critical nature horn length relation rest control system slot machined horn effective length made infinitely adjustable over anticipated range adjusting horn length maximum travel elevator changed until cornering ability associated speed loss through corner liking handle width altered adjust sensitivity plane adjusting done after center gravity CG positioned per drawings simplicity conventional control system shown plans can substituted will some loss performance reasons stated above CONSTRUCTION fuselage made first since its exact width needed accurately locate center ribs Notice fuselage made piece would conventional plane cut two near high point wing necessary install aft fuselage around stabilizer attached before fuselage added allow nose length altered adjust center gravity construction nose can sawed off center still made fit wing aft body Depending engine/muffler combination used CU can altered adjusting nose length minimizes ballast requirements bottom block should glued permanently top block should tack-glued removal installing aft fuselage around stabilizer Note cowling hold-down consists two screws front tie blind nuts located 3A2 plywood nm two screws side body tie tabs cowling reason tabs no room conventional attachment point rear cowling since tank vents landing gear mount tank installation would interfere bottom portion fuselage forward fuselage break /8 Lite Ply grain running fore aft provide nose gear mount Under neath plywood l/ balsa grain running across fuselage adds significant stiffness bottom very little weight increase Blind nuts used conjunction nylon clips fasten nose gear One-eighth-inch aluminum plates used under engine prevent denting bearers engine bolted Once fuselage complete wing construction can started ribs made placing thirteen 342-inch sheets between 1A6 plywood templates drilling precise 3/s-inchdiameter holes installing brass tube hole prior carving rib stacks down templates holes ribs best cut using drill press sharpened piece 3/ brass tubing conventional drill bit will produce very poor quality hole drilling through stack balsa ribs marked will oriented jig bars same way during carving process cancels out error introduced jig alignment holes exactly centerline ribs After ribs made innermost outermost ribs traced cut -inch sheet balsa two ribs need made wider facilitate construction provide additional strength ribs slid onto jig bars use jig bars demon strated years ago Al Rabe far away accurate way construct built-up wing does work exceptionally well does increase construction time actually makes wing go together very easily Now should evident fuselage constructed first two -inch-sheet center ribs must located exact fuselage width since will important glue joint attach fuselage wing Use fuselage nose portion 28 Model Aviation covering slotted same manner stabi lizer receive rear fuselage section CG position determined pinning nose section place temporarily attaching hardware Incidence meter level used ensure thrustline wing centerline parallel Jig attaches engine mounts supports model comfortable heiaht durina finishina match wing color fuselage finished automotive lacquer over dope tissue talc Full Size Plans AvailableSee Page 184 -r CONVENTIONAL MELLORANE RUTFINL11 - IWINO HUMBUG 91 spacer locate center ribs prior attaching trailing edge sheeting leading edge spars Note slots center ribs bellcrank platform different depending control system used After trailing edge sheeting leading edge spars place landing gear mounts leading edge sheeting installed Tilt assembly edge run CyA glue down rib/sheet joint sure joints secure Install vertical shear webs position jig bars will allow glue shear webs between trailing edge planking Install -inch-wide cap strips ribs lightly block sand wing point structure relatively rigid stable alignment bars can removed best done attaching drill motor bars slowly spinning pulled structure Install remainder vertical shear webs blocked jig bars install belicrank mount controls can now added conventional bellcrank system used belicrank mount can installed centerline ribs non linear system used bellcrank mount must lowered allow height required transfer arm Complete wing installing pushrod wing tips wing tip box center section planking wing tip unusual centerline leadout guide installed 4 inch below centerline wing compensate vertical center gravity being below wing center line because weight engine landing gear guide location determined empirically hanging plane leadouts trying different locations sighting against plumb bob until proper position determined Cut window top center section planking completed wing neutral position bellcrank can seen will important stabilizer/elevator installed wing can now covered MonoKote July1993 29 tIIfl Type Nostalgia CL Stunt Wingspan 561/2 inches Recommended engine size type 05 32 muffler Type construction Built-up Type of covering/finish recommended MonoKote wing stabilizer booms automotive lacquer over tissue talc dope fuselage After final trim applied clear acrylic enamel used complete fuelproofing Highly modified Zinger 10 x 5 prop has worked best Humbua 91 Full details text Nose length rudder height visible differences between Humbug 91 original CENTURY JET MODELS INC 8 Martha Ct Sumter SC 29150 803 775-6491 RETRACT SELECTOR SPEED CONTROL VALVE 8305 Regency Woods Way Louisville KY 40220 502 491-4114 Four Infinite Adjustment Screws 2 Up 2 Down Compatible air system Dim 3/8 xls 1-1/4 $2495 Wt 15 oz Semi & Deluxe Ducted Fan Jet Kits Eposy fiberglass fuselage canopy foam wings plans instructions Intake/Exhaust System euc F-i 00 F-100 Hun basic kit $18999 1/8 Scale 50 Removable Wings Length 63 Sport Hawk MK II basic kit $18988 e P&H Easy buildl Removable wing Length 59 F-105 Thunderchief basic kit $23900 e P&H Length 73 77-91 Engine No Cheater Hole F-4 Phantom basic kit $59900 HEW 1/7 Scale Twin Engine Aileron/Spoiler Config Length 90 Removable 61 Wings LE/TE flaps Deluse kit DC wood I/B pylons CF kit plus morel Landing gear tires brakes available FLY THE F-100 SUPER SABRE FROM COMPARE OUR RETRACTS TO THEIRS Stainless Struts cut FREEl Stainless Torque Linksl Different strut configurations * 1 Year Limited Warranty GIANT MAIN RETRACTS STANDARD OR 900 ROTAl 30-50 lb aircraft 2 sets 1 Standard 900 minutes 7Q0 1100 retract angle Over-center lock down Nose gear available $27500 pair Wt 15 lbs Complete Air System Axle Installed Parts Service 30 Day Refund SCALE MAIN RETRACTS STANDARD OR 900 ROTATE Fits PICA Skys F-Si 1/5 Yellow A/C Ziroli Bud Nosen plus Choice 91 Plyon Winners Handles 20-25 lb aircraft 8497 retract angle Positive lock up lock down Optional wire struts Nose gear available $19900 pair Wt 22 oz NEW 1/5 SCALE P-Si & SPITFIRE products proudly MADE IN THE USAI TIRED OF DRAGGING YOUR WING TIPS ON ThE GROUND. WV DUCTS FOR VIOJETT OR DYNAMAX PLEASE SPECIFY VERY COMPLETE KIT F100....... $550 VIDEO TAPE MANUAL $20 F100 DEMO TAPE .$10 FREE PITOT POWER$8SSH OFFSET DOOR HINGES B FOR $8 CALL FOR QUANTITY PRICES USHER ENTERPRISES INC 1017 SE FRONTAGE RD BOX 511 NORTH PLAINS OR 97133 503647 0015 booms made next sandwiching length Y32 plywood between two pieces 3/ts balsa makes extremely stiff light boom t/2 ounce Mono Kote covering wrapped around edge joins wing Cut away just enough effect good bond wing Cut away just enough MonoKote wing good glue jointso no bare wood exposed outboard booms booms glued wing using slow-curing epoxy gives time accurately align well wipe away excess glue alcohol thinner stabilizer elevator made U -inch sheet balsa covered MonoKote prior installation cutting slots covering per booms stabilizer now glued booms taking care locate accurately relative wing Note body glued time placed wing reference stabilizer alignment Now look window wing center section planking place bellcrank neutral position Tape pushrod wing cannot move pushrod attached elevator horn elevator temporarily held place hinges glue hinges time clevis adjusted until elevator neutral pushrodlbellcrank maintained neutral position point release tape pushrod check action controls Remove top block rear portion fuselage install aft body around stabilizer taking care put load stabilizer Cut slots MonoKote attach rear fuselage wing Glue top block cut slot fin At this point nose portion use age can pinned place center gravity can determined installing hardware plane nose heavy fuselage can cut center section shortened until proper center gravity approximately t/8 inch front position shown plans weight fillets paint will shift center gravity slightly aft entire plane painted rather covered MonoKote will have guess weight paint its effect center gravity determine nose length will require minimum ballast Glue fuselage slow-curing epoxy using Robart incidence meter conjunction bubble level ensure thrustline parallel wing centerline Glass nose using 3¼-ounce cloth epoxy fin can permanently glued fuselage canopy added complete framing aircraft fuselage can painted per favorite finishing technique model standard dope tissue talc finish used fillthe grain Since commercial modeling dopes good match Continued page 38 30 Model Aviation t day Saturday OUTLAWFAI COM BAT FIrst match starts 1000 am Saturday Entry Fee $700Open Juniors $500 Sponsored Betty Fox Doc Passen Awards prizes third place Special prize highest place Junior Second day Sunday SUPER-SLOW COMBAT Entry Fee $1000Open Juniors $500 Sponsored FOX Manufacturing DoCs Generix Controline Kits Doc Passen Contest Director information call Write PO Box 111 Jasonville IN 47438 Telephone 812 665-3723 2 days Control Line Combat Wood Hand Selected Fiberglass Cowl Complete Plans Parts Hand Cut Instruction Manual Photo Page order kits call 1-800-327-7198 catalog fine kits send $400Idaho Residents Add 5% State Sales Tax Gasoline fueled Produces 3 foot flame will power planes up 228 mph Designed FUN EASY build home shop about 8 hours using materials already have such aerosol spray can combustion chamber Only simple hand tools needed Both high performance jet engines FUN EASY build STEP BY STEP DETAILED FULL SIZE plan sets complete fuel ignition systems JOIN THE JET AGE sending $995 3hp plan set $1295 7hp plan set both sets $2000 JET ENGINE10241 Ridgewood El Paso Texas 79925 AFTER YOU DID ALL THE WORK WHY LET YOUR AIRPLANE DO ALL THE FLYING HumbuglBaron Continued page 30 white MonoKote used automotive lacquer After trim paint canopy can sealed Ditzler acrylic enamel completely fuel proof finish applying final clear coat recommended masking tape placed slightly outside fillet enamel can run around edge fillet seal edge use 3M fine line tape masking gives clean edge leaves no residue removed Remember pull tape off enamel still tacky prevent bonding tape plane allow enamel seal edge During finish workincluding doping applying paper fillets spraying maskingI use ajig attaches engine mounts suspends plane comfortable height Complete paint trim rudder elevator hinging landing gear installation plane held jig FLYING AND TRIMMING Since Humbug has no flaps easier adjust conventional stunter First install ballast required position center gravity shown plans stability standpoint plane will tolerate aft center gravity line tension positive under varied condi tions center gravity aft position shown plans Set leadouts line shown plans Test flights should short lines 62-64 feet x 015 safety Once model trimmed out 65-68 feet optimum Place approximately e weight tip box Adjust elevator horn provide 250 travel direction started four-inch-wide handle As stunters prop selection criti cal amazing little piece wood can affect flight performance prefer wood propsthey readily modified light weight keeps precession minimum get stunt plane pitch gauge must can make blades accurate pitch gauge can also determine exactly way need adjust pitch obtain desired performance general lower pitch greater vertical capability provided engine can turn prop fast enough give adequate airspeed Increasing pitch will increase airspeed will also increase tendency whip up windy conditions Increased diameter also increases vertical capability cost increased whip-up wind Changing blade shape alters power requirements may cause corresponding change airspeed thrust Finding trade-off between diameter pitch blade shape challenge Humbug 91 can save some time giving dimensions best prop date Start Zinger Continued page 129 38 Model Aviation 4PUGNACIOUS PUSSY CAT 1/4 scale Gee Bee Model Y 9017 lbs 3 7 HP PULSE JET ENGINES AVAILABLE BUILD & FLY THE miniMAX VflI IRFI Fl ampion ana- uomputer uesigneoMss serve Urand unampion ultralightPart 103 UltralightEasy construction 1989 Sun-N-Pun Fly-InWood construction TEAM INC 10790-MA Ivy Bluff Rd Bradyville TN 37026615-765-5397 HumbuglBaron Continued page 38 10 x 5 measured pitch 46 5 inches de-pitch true 40 inches stations Next cut diameter 91/2 inches using dial calipers exactly measure blades length carve sweep leading edge starting approximately inch tip ending tip diameter about 1/ inch Balance blade minimize vibration Carefully check flying site presence small rocks tricycle landing gear thin prop turning high rpm can easily broken leading shaft run can damage airframe Set engine hard two-cycle clearly off maximum power 91/2 x 4 prop lap times should 4 5 seconds Check wings level both upright inverted flight wing high steam wing over kettle boiling water until model flies level both upright inverted found wing obviously need steaming based initial flights warp readily detected sighting down trailing edge event steam wing direction indicated attitude plane level flight wing high both directions add tip weight low both ways remove weight Next make sure engine running same both attitudes Checking lap times both upright inverted good way determine tank needs shimming plane slower right-sideup inverted shim tank down until lap times way close equal Once above steps have completed final trimming matter adjusting control travel trade off cornering against loss airspeed adjusting handle width suit needs ended up 220 elevator travel Minor adjustments leadout rake can made adjusting up line improve inside maneuvers down line outside maneuvers Small changes prop diameter 1/s inch time will result tighter slower corners diameter decreased opposite effect diameter increased As high-performance vehicle very small adjustments have significant effects flight character istics 1/s-inch change leadout rake few mph change airspeed will readily noticed handle possible adjustments very wide range performance handling characteristics available flier Humbug will utilize trimming flying skills hand can trimmed fly like trainer other can trimmed deliver performance tax experienced pilot make choice ess Series U-Control Kits Beginners *0 06 wests new Success Series 049 U-Control kits perfect introduction building flying Featuring illustrated step-by-step Success Series construction manuals teach build paint fly models Kits include Micro-Cut Quality parts pre-formed wire parts wheels bellcrank colorful self adhesive markingsqp line Famous Fighters World War II designed use Cox Black Widow engine See products favorite hobby retailer todayl Famous Fighters World War II Models Available #258-Zero *259-Corsairshown #260-Thunderbolt #261 -FockeWuif Midwest Products Co. Inc 4005 Indiana St PO Box 364 Hobart IN 46342 219942-1134 FAX 219 947-23471 992 Midwest Producta CoInc ......... 8055279114 RIC GOODIES 1805 581-5061 cHRAN ST STE 281 SIMI VLY cA 93065 ER & AIRPLANE KITS #3 0 SPANREG GENESIS69$4295 SPEC 2-3 CH RADIO$35 75** STABLE FLYING WING GLIDER FOR HAND LAUNCH HI-START OR CLIFF SOARING MISPAN 100 SQIN 2-3 CH RADIO 06 020 GAS POWERED EASY TO BUILD & FLY DESIGNED FOR MICRO RADIO EQUIPMENT REG $20SSPEC $1885** ERTABLENEW OLD-TIMER RUBBER ROG OR ROW 6 DIE CUT BALSAPLANS INSTRUCTIONS TISSUE CANOPY AND RUBBER MOTOR REG $2995 SPEC $2695** 0 6 PRAIRIE BIRD 50 05 ELECTRIC 0 423 SQIN R/C TRAINER ANYONE CAN BUILD & FLYI $53 95SPEC $4860* SHIPPING INCLUDED IN CONT USA es Cash Cards 6% 0 Sales Tax Cat $1 USA $3 Foreign July1993 129
Edition: Model Aviation - 1993/07
Page Numbers: 26, 27, 28, 29, 30, 38, 129
HUMBUG 91 OLD-TIMER Nostalgia events competitive models have grown point rival corresponding contemporary events popularity Control Line Stunt no exception trend attraction old-time pre 1952 stunt planes unique personalities since typically offer performance presentday contest models Some Nostalgia stunters designs 25 years old exhibit performance equal greater present-day models Such case Humbug flapless 19-powered Humbug conceived 1966 Bill Netzeband clearly radical Revised version 1966 design Nostalgia Stunt flying features nonlinear control system U Robert Baron departure designs period Though approximately same wing area its competition Humbug used engine half size flapped stunters day attack pattern vengeance using full 70 feet line event allows Since flown days muffled engine too anemic acceptable performance high-revving Veco 19 produced earsplitting noise turning 8 x 5 prop about 12000 rpm Humbug never galned much acceptance stunt community becauseof its deviant appearance noisy engine example plane scored highest flying points two Nationals events finished out running due low static points 40 points available time Clearly performance package lacking fact fellow modeler said good-looking Humbug would oxymoron thought would interesting revisit unusual plane see flew after updating modem engine revised control system some structural improve ments new version equipped withan OS 28a muffler nonlinear control system carbon fiber wing spars has resulted plane silly Thats righta plane makes giggle updated power plant Humbug 91 can easily consecutive vertical square eights followed consecutive hourglasses After flying plane began wonder what would have happened stunt per formance rather package ruled roost last 25 years modifications spirit Nostalgia Stunt flying has maintained appearance original essentially unchanged Aside slight change nose length accommodate added weight muffler minor reduction rudder height outward appearance indistinguishable original except avid aficionados Critical changes structure control system power plant have incorporated modifica tions improve Humbugs performance life changing its fundamental character first change upgrading power plant easy engines have come market last 20 years substantial increases horsepower due Schnuerle porting better metallurgy closer manufacturing tolerances Schnuerle-type engine partic ularly suited Humbug design requirement constant high rpm rather traditional two- four-cycle run normally used Stunt An OS 28 used because its excellent construction twin ball bearings light weight engine comes effective muffler significant back pressure stock muffler power significantly greater original Clarence Lee-modified Veco 19 proved excellent selection OS readily turns 91/2-inch prop well enough result same fivesecond lap times original 26 Model Aviation 4Robert Baron Humbug 91 1966 version used Veco 19 power model uses muffled OS 32 Profile view shows tricycle landing gear Humbug 91 uses modern construction techniques retains appearance original engine has superseded OS 32 slightly heavier because fins cylinder larger otherwise very similar 32 turns prop es greater diameter old Veco 19 could resulting much thrust during maneuvers counts enables model corner harder original main taining sufficient speed clean exit tank set up run either conventional vent uniflo muffler pressure best runs obtained using uniflo no muffler pressure engine set just below maximum power runs hard two-cycle entire flight Fuel 10% nitro inlet diameter 250 inches muffler exhaust opening enlarged stock diameter 250 inches 270 inches 010 head gasket used addition stock gasket T greatest potential improvement after two decades progress change construction techniques did see compelling need change some structure main spar particular also assembly sequence used second time around almost completely reverse original main structural problem previous Humbugs severe cornering loads fatigued broke wood wing spar after few hundred flights performance plane degenerated Part problem spars carried through original models center section also suspected wood fatigue particularly since MonoKote used place paint paint adds substantial amount strength wood new version unidirectionai carbon fiber glued opposite sides -inch-square spars carried through center joined two pieces -inch square spar carbon fiber does bond particularly well balsa compression carbon fiber peels away under relatively little load bonding carbon fiber opposite sides side always tension minimizes amount spar can deflect Using technique rela tively low peel strength carbonfiber-to-balsa bond circumvented essence spar becomes I-beam two spars joined vertical shear webs entire structure becomes extremely stiff torsional strength wing nor significantly improved use carbon fiber spars does appear serious problem Im sure however additional torsional stiffness would improve stability wind tried use carbon tows running 450 angles between ribs develop torsional stiffness could get sufficiently reliable bond between balsa carbon fiber sheeting ribs able transmit loads fibers tried various brands cyanoacrylate CyA glues acceler ators success Bonding unidi rectional fibers epoxy throughout wing frame too tedious abandoned further attempts incor porate carbon fiber structure fter addressing structural problems original Humbug finding suitable modern power plant/muffler combination next challenge control system by-product exceptional performance original plane its control sensitivity level flight round maneuvers necessitated hours practice stability problemthe Humbug stable control inputs necessary level flight round maneuvers subtle hard make minor corrections desired control system slowed inputs low control deflections less 100 allowed full control needed squares Such system designed Bill Netzeband 10 years ago incorporated revolutionary /2A stunter called Barecat Bill found unless such system incorporated Humbug-type model airplanes performance would always have backed off because limitations imposed need fly level still able perform accurate round maneuvers nonlinear system analogous variable-ratio steering automobile results dramatic improvement ability fly level execute round maneuvers sacrificing planes ultimate performance square 30% increase speed control system extremes travel results corresponding 30% loss mechanical advantage means unless control forces kept light through aerodynamic balancing small moving surfaces system will unable generate enough torque full travel controls Such case conventional flapped stunterthe high binge moments required actuate flaps too much control system handle important remember control line system limited force available force limited line tension generated centrifugal force plane Once July1993 27 Fuselage cut near airfoils high point allow stabilizer installation CG adjustment nose section ot iuseiage used spacer locate slotted center wing ribs Wing spars LE TE sheeting cap strips some shear webs have installed point Belicrank mount nonlinear control system installed below rib centerline transfer arm clearance -inch sheet balsa stabilizer covered prior installation slotted attachment points control deflection demands exceed can generated line tension no additional deflection hence lift can obtained system requires careful fitting installation way accurately establish critical slot hole locations using millthe tolerances too demanding hand work Note particularly important system neutral position elevator neutral up down control response will significantly different addition length control horn elevator does simply change sensitivity handle system length elevator control horn determines maximum travel elevator determines extent nonlinear aspects system will observed flight properties airplane different conven tional system elevator horn length changes relationship between handle movement control deflection standpoint control sensitivity changing handle width conventional system will have effect identical changing horn length Because critical nature horn length relation rest control system slot machined horn effective length made infinitely adjustable over anticipated range adjusting horn length maximum travel elevator changed until cornering ability associated speed loss through corner liking handle width altered adjust sensitivity plane adjusting done after center gravity CG positioned per drawings simplicity conventional control system shown plans can substituted will some loss performance reasons stated above CONSTRUCTION fuselage made first since its exact width needed accurately locate center ribs Notice fuselage made piece would conventional plane cut two near high point wing necessary install aft fuselage around stabilizer attached before fuselage added allow nose length altered adjust center gravity construction nose can sawed off center still made fit wing aft body Depending engine/muffler combination used CU can altered adjusting nose length minimizes ballast requirements bottom block should glued permanently top block should tack-glued removal installing aft fuselage around stabilizer Note cowling hold-down consists two screws front tie blind nuts located 3A2 plywood nm two screws side body tie tabs cowling reason tabs no room conventional attachment point rear cowling since tank vents landing gear mount tank installation would interfere bottom portion fuselage forward fuselage break /8 Lite Ply grain running fore aft provide nose gear mount Under neath plywood l/ balsa grain running across fuselage adds significant stiffness bottom very little weight increase Blind nuts used conjunction nylon clips fasten nose gear One-eighth-inch aluminum plates used under engine prevent denting bearers engine bolted Once fuselage complete wing construction can started ribs made placing thirteen 342-inch sheets between 1A6 plywood templates drilling precise 3/s-inchdiameter holes installing brass tube hole prior carving rib stacks down templates holes ribs best cut using drill press sharpened piece 3/ brass tubing conventional drill bit will produce very poor quality hole drilling through stack balsa ribs marked will oriented jig bars same way during carving process cancels out error introduced jig alignment holes exactly centerline ribs After ribs made innermost outermost ribs traced cut -inch sheet balsa two ribs need made wider facilitate construction provide additional strength ribs slid onto jig bars use jig bars demon strated years ago Al Rabe far away accurate way construct built-up wing does work exceptionally well does increase construction time actually makes wing go together very easily Now should evident fuselage constructed first two -inch-sheet center ribs must located exact fuselage width since will important glue joint attach fuselage wing Use fuselage nose portion 28 Model Aviation covering slotted same manner stabi lizer receive rear fuselage section CG position determined pinning nose section place temporarily attaching hardware Incidence meter level used ensure thrustline wing centerline parallel Jig attaches engine mounts supports model comfortable heiaht durina finishina match wing color fuselage finished automotive lacquer over dope tissue talc Full Size Plans AvailableSee Page 184 -r CONVENTIONAL MELLORANE RUTFINL11 - IWINO HUMBUG 91 spacer locate center ribs prior attaching trailing edge sheeting leading edge spars Note slots center ribs bellcrank platform different depending control system used After trailing edge sheeting leading edge spars place landing gear mounts leading edge sheeting installed Tilt assembly edge run CyA glue down rib/sheet joint sure joints secure Install vertical shear webs position jig bars will allow glue shear webs between trailing edge planking Install -inch-wide cap strips ribs lightly block sand wing point structure relatively rigid stable alignment bars can removed best done attaching drill motor bars slowly spinning pulled structure Install remainder vertical shear webs blocked jig bars install belicrank mount controls can now added conventional bellcrank system used belicrank mount can installed centerline ribs non linear system used bellcrank mount must lowered allow height required transfer arm Complete wing installing pushrod wing tips wing tip box center section planking wing tip unusual centerline leadout guide installed 4 inch below centerline wing compensate vertical center gravity being below wing center line because weight engine landing gear guide location determined empirically hanging plane leadouts trying different locations sighting against plumb bob until proper position determined Cut window top center section planking completed wing neutral position bellcrank can seen will important stabilizer/elevator installed wing can now covered MonoKote July1993 29 tIIfl Type Nostalgia CL Stunt Wingspan 561/2 inches Recommended engine size type 05 32 muffler Type construction Built-up Type of covering/finish recommended MonoKote wing stabilizer booms automotive lacquer over tissue talc dope fuselage After final trim applied clear acrylic enamel used complete fuelproofing Highly modified Zinger 10 x 5 prop has worked best Humbua 91 Full details text Nose length rudder height visible differences between Humbug 91 original CENTURY JET MODELS INC 8 Martha Ct Sumter SC 29150 803 775-6491 RETRACT SELECTOR SPEED CONTROL VALVE 8305 Regency Woods Way Louisville KY 40220 502 491-4114 Four Infinite Adjustment Screws 2 Up 2 Down Compatible air system Dim 3/8 xls 1-1/4 $2495 Wt 15 oz Semi & Deluxe Ducted Fan Jet Kits Eposy fiberglass fuselage canopy foam wings plans instructions Intake/Exhaust System euc F-i 00 F-100 Hun basic kit $18999 1/8 Scale 50 Removable Wings Length 63 Sport Hawk MK II basic kit $18988 e P&H Easy buildl Removable wing Length 59 F-105 Thunderchief basic kit $23900 e P&H Length 73 77-91 Engine No Cheater Hole F-4 Phantom basic kit $59900 HEW 1/7 Scale Twin Engine Aileron/Spoiler Config Length 90 Removable 61 Wings LE/TE flaps Deluse kit DC wood I/B pylons CF kit plus morel Landing gear tires brakes available FLY THE F-100 SUPER SABRE FROM COMPARE OUR RETRACTS TO THEIRS Stainless Struts cut FREEl Stainless Torque Linksl Different strut configurations * 1 Year Limited Warranty GIANT MAIN RETRACTS STANDARD OR 900 ROTAl 30-50 lb aircraft 2 sets 1 Standard 900 minutes 7Q0 1100 retract angle Over-center lock down Nose gear available $27500 pair Wt 15 lbs Complete Air System Axle Installed Parts Service 30 Day Refund SCALE MAIN RETRACTS STANDARD OR 900 ROTATE Fits PICA Skys F-Si 1/5 Yellow A/C Ziroli Bud Nosen plus Choice 91 Plyon Winners Handles 20-25 lb aircraft 8497 retract angle Positive lock up lock down Optional wire struts Nose gear available $19900 pair Wt 22 oz NEW 1/5 SCALE P-Si & SPITFIRE products proudly MADE IN THE USAI TIRED OF DRAGGING YOUR WING TIPS ON ThE GROUND. WV DUCTS FOR VIOJETT OR DYNAMAX PLEASE SPECIFY VERY COMPLETE KIT F100....... $550 VIDEO TAPE MANUAL $20 F100 DEMO TAPE .$10 FREE PITOT POWER$8SSH OFFSET DOOR HINGES B FOR $8 CALL FOR QUANTITY PRICES USHER ENTERPRISES INC 1017 SE FRONTAGE RD BOX 511 NORTH PLAINS OR 97133 503647 0015 booms made next sandwiching length Y32 plywood between two pieces 3/ts balsa makes extremely stiff light boom t/2 ounce Mono Kote covering wrapped around edge joins wing Cut away just enough effect good bond wing Cut away just enough MonoKote wing good glue jointso no bare wood exposed outboard booms booms glued wing using slow-curing epoxy gives time accurately align well wipe away excess glue alcohol thinner stabilizer elevator made U -inch sheet balsa covered MonoKote prior installation cutting slots covering per booms stabilizer now glued booms taking care locate accurately relative wing Note body glued time placed wing reference stabilizer alignment Now look window wing center section planking place bellcrank neutral position Tape pushrod wing cannot move pushrod attached elevator horn elevator temporarily held place hinges glue hinges time clevis adjusted until elevator neutral pushrodlbellcrank maintained neutral position point release tape pushrod check action controls Remove top block rear portion fuselage install aft body around stabilizer taking care put load stabilizer Cut slots MonoKote attach rear fuselage wing Glue top block cut slot fin At this point nose portion use age can pinned place center gravity can determined installing hardware plane nose heavy fuselage can cut center section shortened until proper center gravity approximately t/8 inch front position shown plans weight fillets paint will shift center gravity slightly aft entire plane painted rather covered MonoKote will have guess weight paint its effect center gravity determine nose length will require minimum ballast Glue fuselage slow-curing epoxy using Robart incidence meter conjunction bubble level ensure thrustline parallel wing centerline Glass nose using 3¼-ounce cloth epoxy fin can permanently glued fuselage canopy added complete framing aircraft fuselage can painted per favorite finishing technique model standard dope tissue talc finish used fillthe grain Since commercial modeling dopes good match Continued page 38 30 Model Aviation t day Saturday OUTLAWFAI COM BAT FIrst match starts 1000 am Saturday Entry Fee $700Open Juniors $500 Sponsored Betty Fox Doc Passen Awards prizes third place Special prize highest place Junior Second day Sunday SUPER-SLOW COMBAT Entry Fee $1000Open Juniors $500 Sponsored FOX Manufacturing DoCs Generix Controline Kits Doc Passen Contest Director information call Write PO Box 111 Jasonville IN 47438 Telephone 812 665-3723 2 days Control Line Combat Wood Hand Selected Fiberglass Cowl Complete Plans Parts Hand Cut Instruction Manual Photo Page order kits call 1-800-327-7198 catalog fine kits send $400Idaho Residents Add 5% State Sales Tax Gasoline fueled Produces 3 foot flame will power planes up 228 mph Designed FUN EASY build home shop about 8 hours using materials already have such aerosol spray can combustion chamber Only simple hand tools needed Both high performance jet engines FUN EASY build STEP BY STEP DETAILED FULL SIZE plan sets complete fuel ignition systems JOIN THE JET AGE sending $995 3hp plan set $1295 7hp plan set both sets $2000 JET ENGINE10241 Ridgewood El Paso Texas 79925 AFTER YOU DID ALL THE WORK WHY LET YOUR AIRPLANE DO ALL THE FLYING HumbuglBaron Continued page 30 white MonoKote used automotive lacquer After trim paint canopy can sealed Ditzler acrylic enamel completely fuel proof finish applying final clear coat recommended masking tape placed slightly outside fillet enamel can run around edge fillet seal edge use 3M fine line tape masking gives clean edge leaves no residue removed Remember pull tape off enamel still tacky prevent bonding tape plane allow enamel seal edge During finish workincluding doping applying paper fillets spraying maskingI use ajig attaches engine mounts suspends plane comfortable height Complete paint trim rudder elevator hinging landing gear installation plane held jig FLYING AND TRIMMING Since Humbug has no flaps easier adjust conventional stunter First install ballast required position center gravity shown plans stability standpoint plane will tolerate aft center gravity line tension positive under varied condi tions center gravity aft position shown plans Set leadouts line shown plans Test flights should short lines 62-64 feet x 015 safety Once model trimmed out 65-68 feet optimum Place approximately e weight tip box Adjust elevator horn provide 250 travel direction started four-inch-wide handle As stunters prop selection criti cal amazing little piece wood can affect flight performance prefer wood propsthey readily modified light weight keeps precession minimum get stunt plane pitch gauge must can make blades accurate pitch gauge can also determine exactly way need adjust pitch obtain desired performance general lower pitch greater vertical capability provided engine can turn prop fast enough give adequate airspeed Increasing pitch will increase airspeed will also increase tendency whip up windy conditions Increased diameter also increases vertical capability cost increased whip-up wind Changing blade shape alters power requirements may cause corresponding change airspeed thrust Finding trade-off between diameter pitch blade shape challenge Humbug 91 can save some time giving dimensions best prop date Start Zinger Continued page 129 38 Model Aviation 4PUGNACIOUS PUSSY CAT 1/4 scale Gee Bee Model Y 9017 lbs 3 7 HP PULSE JET ENGINES AVAILABLE BUILD & FLY THE miniMAX VflI IRFI Fl ampion ana- uomputer uesigneoMss serve Urand unampion ultralightPart 103 UltralightEasy construction 1989 Sun-N-Pun Fly-InWood construction TEAM INC 10790-MA Ivy Bluff Rd Bradyville TN 37026615-765-5397 HumbuglBaron Continued page 38 10 x 5 measured pitch 46 5 inches de-pitch true 40 inches stations Next cut diameter 91/2 inches using dial calipers exactly measure blades length carve sweep leading edge starting approximately inch tip ending tip diameter about 1/ inch Balance blade minimize vibration Carefully check flying site presence small rocks tricycle landing gear thin prop turning high rpm can easily broken leading shaft run can damage airframe Set engine hard two-cycle clearly off maximum power 91/2 x 4 prop lap times should 4 5 seconds Check wings level both upright inverted flight wing high steam wing over kettle boiling water until model flies level both upright inverted found wing obviously need steaming based initial flights warp readily detected sighting down trailing edge event steam wing direction indicated attitude plane level flight wing high both directions add tip weight low both ways remove weight Next make sure engine running same both attitudes Checking lap times both upright inverted good way determine tank needs shimming plane slower right-sideup inverted shim tank down until lap times way close equal Once above steps have completed final trimming matter adjusting control travel trade off cornering against loss airspeed adjusting handle width suit needs ended up 220 elevator travel Minor adjustments leadout rake can made adjusting up line improve inside maneuvers down line outside maneuvers Small changes prop diameter 1/s inch time will result tighter slower corners diameter decreased opposite effect diameter increased As high-performance vehicle very small adjustments have significant effects flight character istics 1/s-inch change leadout rake few mph change airspeed will readily noticed handle possible adjustments very wide range performance handling characteristics available flier Humbug will utilize trimming flying skills hand can trimmed fly like trainer other can trimmed deliver performance tax experienced pilot make choice ess Series U-Control Kits Beginners *0 06 wests new Success Series 049 U-Control kits perfect introduction building flying Featuring illustrated step-by-step Success Series construction manuals teach build paint fly models Kits include Micro-Cut Quality parts pre-formed wire parts wheels bellcrank colorful self adhesive markingsqp line Famous Fighters World War II designed use Cox Black Widow engine See products favorite hobby retailer todayl Famous Fighters World War II Models Available #258-Zero *259-Corsairshown #260-Thunderbolt #261 -FockeWuif Midwest Products Co. Inc 4005 Indiana St PO Box 364 Hobart IN 46342 219942-1134 FAX 219 947-23471 992 Midwest Producta CoInc ......... 8055279114 RIC GOODIES 1805 581-5061 cHRAN ST STE 281 SIMI VLY cA 93065 ER & AIRPLANE KITS #3 0 SPANREG GENESIS69$4295 SPEC 2-3 CH RADIO$35 75** STABLE FLYING WING GLIDER FOR HAND LAUNCH HI-START OR CLIFF SOARING MISPAN 100 SQIN 2-3 CH RADIO 06 020 GAS POWERED EASY TO BUILD & FLY DESIGNED FOR MICRO RADIO EQUIPMENT REG $20SSPEC $1885** ERTABLENEW OLD-TIMER RUBBER ROG OR ROW 6 DIE CUT BALSAPLANS INSTRUCTIONS TISSUE CANOPY AND RUBBER MOTOR REG $2995 SPEC $2695** 0 6 PRAIRIE BIRD 50 05 ELECTRIC 0 423 SQIN R/C TRAINER ANYONE CAN BUILD & FLYI $53 95SPEC $4860* SHIPPING INCLUDED IN CONT USA es Cash Cards 6% 0 Sales Tax Cat $1 USA $3 Foreign July1993 129
Edition: Model Aviation - 1993/07
Page Numbers: 26, 27, 28, 29, 30, 38, 129
HUMBUG 91 OLD-TIMER Nostalgia events competitive models have grown point rival corresponding contemporary events popularity Control Line Stunt no exception trend attraction old-time pre 1952 stunt planes unique personalities since typically offer performance presentday contest models Some Nostalgia stunters designs 25 years old exhibit performance equal greater present-day models Such case Humbug flapless 19-powered Humbug conceived 1966 Bill Netzeband clearly radical Revised version 1966 design Nostalgia Stunt flying features nonlinear control system U Robert Baron departure designs period Though approximately same wing area its competition Humbug used engine half size flapped stunters day attack pattern vengeance using full 70 feet line event allows Since flown days muffled engine too anemic acceptable performance high-revving Veco 19 produced earsplitting noise turning 8 x 5 prop about 12000 rpm Humbug never galned much acceptance stunt community becauseof its deviant appearance noisy engine example plane scored highest flying points two Nationals events finished out running due low static points 40 points available time Clearly performance package lacking fact fellow modeler said good-looking Humbug would oxymoron thought would interesting revisit unusual plane see flew after updating modem engine revised control system some structural improve ments new version equipped withan OS 28a muffler nonlinear control system carbon fiber wing spars has resulted plane silly Thats righta plane makes giggle updated power plant Humbug 91 can easily consecutive vertical square eights followed consecutive hourglasses After flying plane began wonder what would have happened stunt per formance rather package ruled roost last 25 years modifications spirit Nostalgia Stunt flying has maintained appearance original essentially unchanged Aside slight change nose length accommodate added weight muffler minor reduction rudder height outward appearance indistinguishable original except avid aficionados Critical changes structure control system power plant have incorporated modifica tions improve Humbugs performance life changing its fundamental character first change upgrading power plant easy engines have come market last 20 years substantial increases horsepower due Schnuerle porting better metallurgy closer manufacturing tolerances Schnuerle-type engine partic ularly suited Humbug design requirement constant high rpm rather traditional two- four-cycle run normally used Stunt An OS 28 used because its excellent construction twin ball bearings light weight engine comes effective muffler significant back pressure stock muffler power significantly greater original Clarence Lee-modified Veco 19 proved excellent selection OS readily turns 91/2-inch prop well enough result same fivesecond lap times original 26 Model Aviation 4Robert Baron Humbug 91 1966 version used Veco 19 power model uses muffled OS 32 Profile view shows tricycle landing gear Humbug 91 uses modern construction techniques retains appearance original engine has superseded OS 32 slightly heavier because fins cylinder larger otherwise very similar 32 turns prop es greater diameter old Veco 19 could resulting much thrust during maneuvers counts enables model corner harder original main taining sufficient speed clean exit tank set up run either conventional vent uniflo muffler pressure best runs obtained using uniflo no muffler pressure engine set just below maximum power runs hard two-cycle entire flight Fuel 10% nitro inlet diameter 250 inches muffler exhaust opening enlarged stock diameter 250 inches 270 inches 010 head gasket used addition stock gasket T greatest potential improvement after two decades progress change construction techniques did see compelling need change some structure main spar particular also assembly sequence used second time around almost completely reverse original main structural problem previous Humbugs severe cornering loads fatigued broke wood wing spar after few hundred flights performance plane degenerated Part problem spars carried through original models center section also suspected wood fatigue particularly since MonoKote used place paint paint adds substantial amount strength wood new version unidirectionai carbon fiber glued opposite sides -inch-square spars carried through center joined two pieces -inch square spar carbon fiber does bond particularly well balsa compression carbon fiber peels away under relatively little load bonding carbon fiber opposite sides side always tension minimizes amount spar can deflect Using technique rela tively low peel strength carbonfiber-to-balsa bond circumvented essence spar becomes I-beam two spars joined vertical shear webs entire structure becomes extremely stiff torsional strength wing nor significantly improved use carbon fiber spars does appear serious problem Im sure however additional torsional stiffness would improve stability wind tried use carbon tows running 450 angles between ribs develop torsional stiffness could get sufficiently reliable bond between balsa carbon fiber sheeting ribs able transmit loads fibers tried various brands cyanoacrylate CyA glues acceler ators success Bonding unidi rectional fibers epoxy throughout wing frame too tedious abandoned further attempts incor porate carbon fiber structure fter addressing structural problems original Humbug finding suitable modern power plant/muffler combination next challenge control system by-product exceptional performance original plane its control sensitivity level flight round maneuvers necessitated hours practice stability problemthe Humbug stable control inputs necessary level flight round maneuvers subtle hard make minor corrections desired control system slowed inputs low control deflections less 100 allowed full control needed squares Such system designed Bill Netzeband 10 years ago incorporated revolutionary /2A stunter called Barecat Bill found unless such system incorporated Humbug-type model airplanes performance would always have backed off because limitations imposed need fly level still able perform accurate round maneuvers nonlinear system analogous variable-ratio steering automobile results dramatic improvement ability fly level execute round maneuvers sacrificing planes ultimate performance square 30% increase speed control system extremes travel results corresponding 30% loss mechanical advantage means unless control forces kept light through aerodynamic balancing small moving surfaces system will unable generate enough torque full travel controls Such case conventional flapped stunterthe high binge moments required actuate flaps too much control system handle important remember control line system limited force available force limited line tension generated centrifugal force plane Once July1993 27 Fuselage cut near airfoils high point allow stabilizer installation CG adjustment nose section ot iuseiage used spacer locate slotted center wing ribs Wing spars LE TE sheeting cap strips some shear webs have installed point Belicrank mount nonlinear control system installed below rib centerline transfer arm clearance -inch sheet balsa stabilizer covered prior installation slotted attachment points control deflection demands exceed can generated line tension no additional deflection hence lift can obtained system requires careful fitting installation way accurately establish critical slot hole locations using millthe tolerances too demanding hand work Note particularly important system neutral position elevator neutral up down control response will significantly different addition length control horn elevator does simply change sensitivity handle system length elevator control horn determines maximum travel elevator determines extent nonlinear aspects system will observed flight properties airplane different conven tional system elevator horn length changes relationship between handle movement control deflection standpoint control sensitivity changing handle width conventional system will have effect identical changing horn length Because critical nature horn length relation rest control system slot machined horn effective length made infinitely adjustable over anticipated range adjusting horn length maximum travel elevator changed until cornering ability associated speed loss through corner liking handle width altered adjust sensitivity plane adjusting done after center gravity CG positioned per drawings simplicity conventional control system shown plans can substituted will some loss performance reasons stated above CONSTRUCTION fuselage made first since its exact width needed accurately locate center ribs Notice fuselage made piece would conventional plane cut two near high point wing necessary install aft fuselage around stabilizer attached before fuselage added allow nose length altered adjust center gravity construction nose can sawed off center still made fit wing aft body Depending engine/muffler combination used CU can altered adjusting nose length minimizes ballast requirements bottom block should glued permanently top block should tack-glued removal installing aft fuselage around stabilizer Note cowling hold-down consists two screws front tie blind nuts located 3A2 plywood nm two screws side body tie tabs cowling reason tabs no room conventional attachment point rear cowling since tank vents landing gear mount tank installation would interfere bottom portion fuselage forward fuselage break /8 Lite Ply grain running fore aft provide nose gear mount Under neath plywood l/ balsa grain running across fuselage adds significant stiffness bottom very little weight increase Blind nuts used conjunction nylon clips fasten nose gear One-eighth-inch aluminum plates used under engine prevent denting bearers engine bolted Once fuselage complete wing construction can started ribs made placing thirteen 342-inch sheets between 1A6 plywood templates drilling precise 3/s-inchdiameter holes installing brass tube hole prior carving rib stacks down templates holes ribs best cut using drill press sharpened piece 3/ brass tubing conventional drill bit will produce very poor quality hole drilling through stack balsa ribs marked will oriented jig bars same way during carving process cancels out error introduced jig alignment holes exactly centerline ribs After ribs made innermost outermost ribs traced cut -inch sheet balsa two ribs need made wider facilitate construction provide additional strength ribs slid onto jig bars use jig bars demon strated years ago Al Rabe far away accurate way construct built-up wing does work exceptionally well does increase construction time actually makes wing go together very easily Now should evident fuselage constructed first two -inch-sheet center ribs must located exact fuselage width since will important glue joint attach fuselage wing Use fuselage nose portion 28 Model Aviation covering slotted same manner stabi lizer receive rear fuselage section CG position determined pinning nose section place temporarily attaching hardware Incidence meter level used ensure thrustline wing centerline parallel Jig attaches engine mounts supports model comfortable heiaht durina finishina match wing color fuselage finished automotive lacquer over dope tissue talc Full Size Plans AvailableSee Page 184 -r CONVENTIONAL MELLORANE RUTFINL11 - IWINO HUMBUG 91 spacer locate center ribs prior attaching trailing edge sheeting leading edge spars Note slots center ribs bellcrank platform different depending control system used After trailing edge sheeting leading edge spars place landing gear mounts leading edge sheeting installed Tilt assembly edge run CyA glue down rib/sheet joint sure joints secure Install vertical shear webs position jig bars will allow glue shear webs between trailing edge planking Install -inch-wide cap strips ribs lightly block sand wing point structure relatively rigid stable alignment bars can removed best done attaching drill motor bars slowly spinning pulled structure Install remainder vertical shear webs blocked jig bars install belicrank mount controls can now added conventional bellcrank system used belicrank mount can installed centerline ribs non linear system used bellcrank mount must lowered allow height required transfer arm Complete wing installing pushrod wing tips wing tip box center section planking wing tip unusual centerline leadout guide installed 4 inch below centerline wing compensate vertical center gravity being below wing center line because weight engine landing gear guide location determined empirically hanging plane leadouts trying different locations sighting against plumb bob until proper position determined Cut window top center section planking completed wing neutral position bellcrank can seen will important stabilizer/elevator installed wing can now covered MonoKote July1993 29 tIIfl Type Nostalgia CL Stunt Wingspan 561/2 inches Recommended engine size type 05 32 muffler Type construction Built-up Type of covering/finish recommended MonoKote wing stabilizer booms automotive lacquer over tissue talc dope fuselage After final trim applied clear acrylic enamel used complete fuelproofing Highly modified Zinger 10 x 5 prop has worked best Humbua 91 Full details text Nose length rudder height visible differences between Humbug 91 original CENTURY JET MODELS INC 8 Martha Ct Sumter SC 29150 803 775-6491 RETRACT SELECTOR SPEED CONTROL VALVE 8305 Regency Woods Way Louisville KY 40220 502 491-4114 Four Infinite Adjustment Screws 2 Up 2 Down Compatible air system Dim 3/8 xls 1-1/4 $2495 Wt 15 oz Semi & Deluxe Ducted Fan Jet Kits Eposy fiberglass fuselage canopy foam wings plans instructions Intake/Exhaust System euc F-i 00 F-100 Hun basic kit $18999 1/8 Scale 50 Removable Wings Length 63 Sport Hawk MK II basic kit $18988 e P&H Easy buildl Removable wing Length 59 F-105 Thunderchief basic kit $23900 e P&H Length 73 77-91 Engine No Cheater Hole F-4 Phantom basic kit $59900 HEW 1/7 Scale Twin Engine Aileron/Spoiler Config Length 90 Removable 61 Wings LE/TE flaps Deluse kit DC wood I/B pylons CF kit plus morel Landing gear tires brakes available FLY THE F-100 SUPER SABRE FROM COMPARE OUR RETRACTS TO THEIRS Stainless Struts cut FREEl Stainless Torque Linksl Different strut configurations * 1 Year Limited Warranty GIANT MAIN RETRACTS STANDARD OR 900 ROTAl 30-50 lb aircraft 2 sets 1 Standard 900 minutes 7Q0 1100 retract angle Over-center lock down Nose gear available $27500 pair Wt 15 lbs Complete Air System Axle Installed Parts Service 30 Day Refund SCALE MAIN RETRACTS STANDARD OR 900 ROTATE Fits PICA Skys F-Si 1/5 Yellow A/C Ziroli Bud Nosen plus Choice 91 Plyon Winners Handles 20-25 lb aircraft 8497 retract angle Positive lock up lock down Optional wire struts Nose gear available $19900 pair Wt 22 oz NEW 1/5 SCALE P-Si & SPITFIRE products proudly MADE IN THE USAI TIRED OF DRAGGING YOUR WING TIPS ON ThE GROUND. WV DUCTS FOR VIOJETT OR DYNAMAX PLEASE SPECIFY VERY COMPLETE KIT F100....... $550 VIDEO TAPE MANUAL $20 F100 DEMO TAPE .$10 FREE PITOT POWER$8SSH OFFSET DOOR HINGES B FOR $8 CALL FOR QUANTITY PRICES USHER ENTERPRISES INC 1017 SE FRONTAGE RD BOX 511 NORTH PLAINS OR 97133 503647 0015 booms made next sandwiching length Y32 plywood between two pieces 3/ts balsa makes extremely stiff light boom t/2 ounce Mono Kote covering wrapped around edge joins wing Cut away just enough effect good bond wing Cut away just enough MonoKote wing good glue jointso no bare wood exposed outboard booms booms glued wing using slow-curing epoxy gives time accurately align well wipe away excess glue alcohol thinner stabilizer elevator made U -inch sheet balsa covered MonoKote prior installation cutting slots covering per booms stabilizer now glued booms taking care locate accurately relative wing Note body glued time placed wing reference stabilizer alignment Now look window wing center section planking place bellcrank neutral position Tape pushrod wing cannot move pushrod attached elevator horn elevator temporarily held place hinges glue hinges time clevis adjusted until elevator neutral pushrodlbellcrank maintained neutral position point release tape pushrod check action controls Remove top block rear portion fuselage install aft body around stabilizer taking care put load stabilizer Cut slots MonoKote attach rear fuselage wing Glue top block cut slot fin At this point nose portion use age can pinned place center gravity can determined installing hardware plane nose heavy fuselage can cut center section shortened until proper center gravity approximately t/8 inch front position shown plans weight fillets paint will shift center gravity slightly aft entire plane painted rather covered MonoKote will have guess weight paint its effect center gravity determine nose length will require minimum ballast Glue fuselage slow-curing epoxy using Robart incidence meter conjunction bubble level ensure thrustline parallel wing centerline Glass nose using 3¼-ounce cloth epoxy fin can permanently glued fuselage canopy added complete framing aircraft fuselage can painted per favorite finishing technique model standard dope tissue talc finish used fillthe grain Since commercial modeling dopes good match Continued page 38 30 Model Aviation t day Saturday OUTLAWFAI COM BAT FIrst match starts 1000 am Saturday Entry Fee $700Open Juniors $500 Sponsored Betty Fox Doc Passen Awards prizes third place Special prize highest place Junior Second day Sunday SUPER-SLOW COMBAT Entry Fee $1000Open Juniors $500 Sponsored FOX Manufacturing DoCs Generix Controline Kits Doc Passen Contest Director information call Write PO Box 111 Jasonville IN 47438 Telephone 812 665-3723 2 days Control Line Combat Wood Hand Selected Fiberglass Cowl Complete Plans Parts Hand Cut Instruction Manual Photo Page order kits call 1-800-327-7198 catalog fine kits send $400Idaho Residents Add 5% State Sales Tax Gasoline fueled Produces 3 foot flame will power planes up 228 mph Designed FUN EASY build home shop about 8 hours using materials already have such aerosol spray can combustion chamber Only simple hand tools needed Both high performance jet engines FUN EASY build STEP BY STEP DETAILED FULL SIZE plan sets complete fuel ignition systems JOIN THE JET AGE sending $995 3hp plan set $1295 7hp plan set both sets $2000 JET ENGINE10241 Ridgewood El Paso Texas 79925 AFTER YOU DID ALL THE WORK WHY LET YOUR AIRPLANE DO ALL THE FLYING HumbuglBaron Continued page 30 white MonoKote used automotive lacquer After trim paint canopy can sealed Ditzler acrylic enamel completely fuel proof finish applying final clear coat recommended masking tape placed slightly outside fillet enamel can run around edge fillet seal edge use 3M fine line tape masking gives clean edge leaves no residue removed Remember pull tape off enamel still tacky prevent bonding tape plane allow enamel seal edge During finish workincluding doping applying paper fillets spraying maskingI use ajig attaches engine mounts suspends plane comfortable height Complete paint trim rudder elevator hinging landing gear installation plane held jig FLYING AND TRIMMING Since Humbug has no flaps easier adjust conventional stunter First install ballast required position center gravity shown plans stability standpoint plane will tolerate aft center gravity line tension positive under varied condi tions center gravity aft position shown plans Set leadouts line shown plans Test flights should short lines 62-64 feet x 015 safety Once model trimmed out 65-68 feet optimum Place approximately e weight tip box Adjust elevator horn provide 250 travel direction started four-inch-wide handle As stunters prop selection criti cal amazing little piece wood can affect flight performance prefer wood propsthey readily modified light weight keeps precession minimum get stunt plane pitch gauge must can make blades accurate pitch gauge can also determine exactly way need adjust pitch obtain desired performance general lower pitch greater vertical capability provided engine can turn prop fast enough give adequate airspeed Increasing pitch will increase airspeed will also increase tendency whip up windy conditions Increased diameter also increases vertical capability cost increased whip-up wind Changing blade shape alters power requirements may cause corresponding change airspeed thrust Finding trade-off between diameter pitch blade shape challenge Humbug 91 can save some time giving dimensions best prop date Start Zinger Continued page 129 38 Model Aviation 4PUGNACIOUS PUSSY CAT 1/4 scale Gee Bee Model Y 9017 lbs 3 7 HP PULSE JET ENGINES AVAILABLE BUILD & FLY THE miniMAX VflI IRFI Fl ampion ana- uomputer uesigneoMss serve Urand unampion ultralightPart 103 UltralightEasy construction 1989 Sun-N-Pun Fly-InWood construction TEAM INC 10790-MA Ivy Bluff Rd Bradyville TN 37026615-765-5397 HumbuglBaron Continued page 38 10 x 5 measured pitch 46 5 inches de-pitch true 40 inches stations Next cut diameter 91/2 inches using dial calipers exactly measure blades length carve sweep leading edge starting approximately inch tip ending tip diameter about 1/ inch Balance blade minimize vibration Carefully check flying site presence small rocks tricycle landing gear thin prop turning high rpm can easily broken leading shaft run can damage airframe Set engine hard two-cycle clearly off maximum power 91/2 x 4 prop lap times should 4 5 seconds Check wings level both upright inverted flight wing high steam wing over kettle boiling water until model flies level both upright inverted found wing obviously need steaming based initial flights warp readily detected sighting down trailing edge event steam wing direction indicated attitude plane level flight wing high both directions add tip weight low both ways remove weight Next make sure engine running same both attitudes Checking lap times both upright inverted good way determine tank needs shimming plane slower right-sideup inverted shim tank down until lap times way close equal Once above steps have completed final trimming matter adjusting control travel trade off cornering against loss airspeed adjusting handle width suit needs ended up 220 elevator travel Minor adjustments leadout rake can made adjusting up line improve inside maneuvers down line outside maneuvers Small changes prop diameter 1/s inch time will result tighter slower corners diameter decreased opposite effect diameter increased As high-performance vehicle very small adjustments have significant effects flight character istics 1/s-inch change leadout rake few mph change airspeed will readily noticed handle possible adjustments very wide range performance handling characteristics available flier Humbug will utilize trimming flying skills hand can trimmed fly like trainer other can trimmed deliver performance tax experienced pilot make choice ess Series U-Control Kits Beginners *0 06 wests new Success Series 049 U-Control kits perfect introduction building flying Featuring illustrated step-by-step Success Series construction manuals teach build paint fly models Kits include Micro-Cut Quality parts pre-formed wire parts wheels bellcrank colorful self adhesive markingsqp line Famous Fighters World War II designed use Cox Black Widow engine See products favorite hobby retailer todayl Famous Fighters World War II Models Available #258-Zero *259-Corsairshown #260-Thunderbolt #261 -FockeWuif Midwest Products Co. Inc 4005 Indiana St PO Box 364 Hobart IN 46342 219942-1134 FAX 219 947-23471 992 Midwest Producta CoInc ......... 8055279114 RIC GOODIES 1805 581-5061 cHRAN ST STE 281 SIMI VLY cA 93065 ER & AIRPLANE KITS #3 0 SPANREG GENESIS69$4295 SPEC 2-3 CH RADIO$35 75** STABLE FLYING WING GLIDER FOR HAND LAUNCH HI-START OR CLIFF SOARING MISPAN 100 SQIN 2-3 CH RADIO 06 020 GAS POWERED EASY TO BUILD & FLY DESIGNED FOR MICRO RADIO EQUIPMENT REG $20SSPEC $1885** ERTABLENEW OLD-TIMER RUBBER ROG OR ROW 6 DIE CUT BALSAPLANS INSTRUCTIONS TISSUE CANOPY AND RUBBER MOTOR REG $2995 SPEC $2695** 0 6 PRAIRIE BIRD 50 05 ELECTRIC 0 423 SQIN R/C TRAINER ANYONE CAN BUILD & FLYI $53 95SPEC $4860* SHIPPING INCLUDED IN CONT USA es Cash Cards 6% 0 Sales Tax Cat $1 USA $3 Foreign July1993 129
Edition: Model Aviation - 1993/07
Page Numbers: 26, 27, 28, 29, 30, 38, 129
HUMBUG 91 OLD-TIMER Nostalgia events competitive models have grown point rival corresponding contemporary events popularity Control Line Stunt no exception trend attraction old-time pre 1952 stunt planes unique personalities since typically offer performance presentday contest models Some Nostalgia stunters designs 25 years old exhibit performance equal greater present-day models Such case Humbug flapless 19-powered Humbug conceived 1966 Bill Netzeband clearly radical Revised version 1966 design Nostalgia Stunt flying features nonlinear control system U Robert Baron departure designs period Though approximately same wing area its competition Humbug used engine half size flapped stunters day attack pattern vengeance using full 70 feet line event allows Since flown days muffled engine too anemic acceptable performance high-revving Veco 19 produced earsplitting noise turning 8 x 5 prop about 12000 rpm Humbug never galned much acceptance stunt community becauseof its deviant appearance noisy engine example plane scored highest flying points two Nationals events finished out running due low static points 40 points available time Clearly performance package lacking fact fellow modeler said good-looking Humbug would oxymoron thought would interesting revisit unusual plane see flew after updating modem engine revised control system some structural improve ments new version equipped withan OS 28a muffler nonlinear control system carbon fiber wing spars has resulted plane silly Thats righta plane makes giggle updated power plant Humbug 91 can easily consecutive vertical square eights followed consecutive hourglasses After flying plane began wonder what would have happened stunt per formance rather package ruled roost last 25 years modifications spirit Nostalgia Stunt flying has maintained appearance original essentially unchanged Aside slight change nose length accommodate added weight muffler minor reduction rudder height outward appearance indistinguishable original except avid aficionados Critical changes structure control system power plant have incorporated modifica tions improve Humbugs performance life changing its fundamental character first change upgrading power plant easy engines have come market last 20 years substantial increases horsepower due Schnuerle porting better metallurgy closer manufacturing tolerances Schnuerle-type engine partic ularly suited Humbug design requirement constant high rpm rather traditional two- four-cycle run normally used Stunt An OS 28 used because its excellent construction twin ball bearings light weight engine comes effective muffler significant back pressure stock muffler power significantly greater original Clarence Lee-modified Veco 19 proved excellent selection OS readily turns 91/2-inch prop well enough result same fivesecond lap times original 26 Model Aviation 4Robert Baron Humbug 91 1966 version used Veco 19 power model uses muffled OS 32 Profile view shows tricycle landing gear Humbug 91 uses modern construction techniques retains appearance original engine has superseded OS 32 slightly heavier because fins cylinder larger otherwise very similar 32 turns prop es greater diameter old Veco 19 could resulting much thrust during maneuvers counts enables model corner harder original main taining sufficient speed clean exit tank set up run either conventional vent uniflo muffler pressure best runs obtained using uniflo no muffler pressure engine set just below maximum power runs hard two-cycle entire flight Fuel 10% nitro inlet diameter 250 inches muffler exhaust opening enlarged stock diameter 250 inches 270 inches 010 head gasket used addition stock gasket T greatest potential improvement after two decades progress change construction techniques did see compelling need change some structure main spar particular also assembly sequence used second time around almost completely reverse original main structural problem previous Humbugs severe cornering loads fatigued broke wood wing spar after few hundred flights performance plane degenerated Part problem spars carried through original models center section also suspected wood fatigue particularly since MonoKote used place paint paint adds substantial amount strength wood new version unidirectionai carbon fiber glued opposite sides -inch-square spars carried through center joined two pieces -inch square spar carbon fiber does bond particularly well balsa compression carbon fiber peels away under relatively little load bonding carbon fiber opposite sides side always tension minimizes amount spar can deflect Using technique rela tively low peel strength carbonfiber-to-balsa bond circumvented essence spar becomes I-beam two spars joined vertical shear webs entire structure becomes extremely stiff torsional strength wing nor significantly improved use carbon fiber spars does appear serious problem Im sure however additional torsional stiffness would improve stability wind tried use carbon tows running 450 angles between ribs develop torsional stiffness could get sufficiently reliable bond between balsa carbon fiber sheeting ribs able transmit loads fibers tried various brands cyanoacrylate CyA glues acceler ators success Bonding unidi rectional fibers epoxy throughout wing frame too tedious abandoned further attempts incor porate carbon fiber structure fter addressing structural problems original Humbug finding suitable modern power plant/muffler combination next challenge control system by-product exceptional performance original plane its control sensitivity level flight round maneuvers necessitated hours practice stability problemthe Humbug stable control inputs necessary level flight round maneuvers subtle hard make minor corrections desired control system slowed inputs low control deflections less 100 allowed full control needed squares Such system designed Bill Netzeband 10 years ago incorporated revolutionary /2A stunter called Barecat Bill found unless such system incorporated Humbug-type model airplanes performance would always have backed off because limitations imposed need fly level still able perform accurate round maneuvers nonlinear system analogous variable-ratio steering automobile results dramatic improvement ability fly level execute round maneuvers sacrificing planes ultimate performance square 30% increase speed control system extremes travel results corresponding 30% loss mechanical advantage means unless control forces kept light through aerodynamic balancing small moving surfaces system will unable generate enough torque full travel controls Such case conventional flapped stunterthe high binge moments required actuate flaps too much control system handle important remember control line system limited force available force limited line tension generated centrifugal force plane Once July1993 27 Fuselage cut near airfoils high point allow stabilizer installation CG adjustment nose section ot iuseiage used spacer locate slotted center wing ribs Wing spars LE TE sheeting cap strips some shear webs have installed point Belicrank mount nonlinear control system installed below rib centerline transfer arm clearance -inch sheet balsa stabilizer covered prior installation slotted attachment points control deflection demands exceed can generated line tension no additional deflection hence lift can obtained system requires careful fitting installation way accurately establish critical slot hole locations using millthe tolerances too demanding hand work Note particularly important system neutral position elevator neutral up down control response will significantly different addition length control horn elevator does simply change sensitivity handle system length elevator control horn determines maximum travel elevator determines extent nonlinear aspects system will observed flight properties airplane different conven tional system elevator horn length changes relationship between handle movement control deflection standpoint control sensitivity changing handle width conventional system will have effect identical changing horn length Because critical nature horn length relation rest control system slot machined horn effective length made infinitely adjustable over anticipated range adjusting horn length maximum travel elevator changed until cornering ability associated speed loss through corner liking handle width altered adjust sensitivity plane adjusting done after center gravity CG positioned per drawings simplicity conventional control system shown plans can substituted will some loss performance reasons stated above CONSTRUCTION fuselage made first since its exact width needed accurately locate center ribs Notice fuselage made piece would conventional plane cut two near high point wing necessary install aft fuselage around stabilizer attached before fuselage added allow nose length altered adjust center gravity construction nose can sawed off center still made fit wing aft body Depending engine/muffler combination used CU can altered adjusting nose length minimizes ballast requirements bottom block should glued permanently top block should tack-glued removal installing aft fuselage around stabilizer Note cowling hold-down consists two screws front tie blind nuts located 3A2 plywood nm two screws side body tie tabs cowling reason tabs no room conventional attachment point rear cowling since tank vents landing gear mount tank installation would interfere bottom portion fuselage forward fuselage break /8 Lite Ply grain running fore aft provide nose gear mount Under neath plywood l/ balsa grain running across fuselage adds significant stiffness bottom very little weight increase Blind nuts used conjunction nylon clips fasten nose gear One-eighth-inch aluminum plates used under engine prevent denting bearers engine bolted Once fuselage complete wing construction can started ribs made placing thirteen 342-inch sheets between 1A6 plywood templates drilling precise 3/s-inchdiameter holes installing brass tube hole prior carving rib stacks down templates holes ribs best cut using drill press sharpened piece 3/ brass tubing conventional drill bit will produce very poor quality hole drilling through stack balsa ribs marked will oriented jig bars same way during carving process cancels out error introduced jig alignment holes exactly centerline ribs After ribs made innermost outermost ribs traced cut -inch sheet balsa two ribs need made wider facilitate construction provide additional strength ribs slid onto jig bars use jig bars demon strated years ago Al Rabe far away accurate way construct built-up wing does work exceptionally well does increase construction time actually makes wing go together very easily Now should evident fuselage constructed first two -inch-sheet center ribs must located exact fuselage width since will important glue joint attach fuselage wing Use fuselage nose portion 28 Model Aviation covering slotted same manner stabi lizer receive rear fuselage section CG position determined pinning nose section place temporarily attaching hardware Incidence meter level used ensure thrustline wing centerline parallel Jig attaches engine mounts supports model comfortable heiaht durina finishina match wing color fuselage finished automotive lacquer over dope tissue talc Full Size Plans AvailableSee Page 184 -r CONVENTIONAL MELLORANE RUTFINL11 - IWINO HUMBUG 91 spacer locate center ribs prior attaching trailing edge sheeting leading edge spars Note slots center ribs bellcrank platform different depending control system used After trailing edge sheeting leading edge spars place landing gear mounts leading edge sheeting installed Tilt assembly edge run CyA glue down rib/sheet joint sure joints secure Install vertical shear webs position jig bars will allow glue shear webs between trailing edge planking Install -inch-wide cap strips ribs lightly block sand wing point structure relatively rigid stable alignment bars can removed best done attaching drill motor bars slowly spinning pulled structure Install remainder vertical shear webs blocked jig bars install belicrank mount controls can now added conventional bellcrank system used belicrank mount can installed centerline ribs non linear system used bellcrank mount must lowered allow height required transfer arm Complete wing installing pushrod wing tips wing tip box center section planking wing tip unusual centerline leadout guide installed 4 inch below centerline wing compensate vertical center gravity being below wing center line because weight engine landing gear guide location determined empirically hanging plane leadouts trying different locations sighting against plumb bob until proper position determined Cut window top center section planking completed wing neutral position bellcrank can seen will important stabilizer/elevator installed wing can now covered MonoKote July1993 29 tIIfl Type Nostalgia CL Stunt Wingspan 561/2 inches Recommended engine size type 05 32 muffler Type construction Built-up Type of covering/finish recommended MonoKote wing stabilizer booms automotive lacquer over tissue talc dope fuselage After final trim applied clear acrylic enamel used complete fuelproofing Highly modified Zinger 10 x 5 prop has worked best Humbua 91 Full details text Nose length rudder height visible differences between Humbug 91 original CENTURY JET MODELS INC 8 Martha Ct Sumter SC 29150 803 775-6491 RETRACT SELECTOR SPEED CONTROL VALVE 8305 Regency Woods Way Louisville KY 40220 502 491-4114 Four Infinite Adjustment Screws 2 Up 2 Down Compatible air system Dim 3/8 xls 1-1/4 $2495 Wt 15 oz Semi & Deluxe Ducted Fan Jet Kits Eposy fiberglass fuselage canopy foam wings plans instructions Intake/Exhaust System euc F-i 00 F-100 Hun basic kit $18999 1/8 Scale 50 Removable Wings Length 63 Sport Hawk MK II basic kit $18988 e P&H Easy buildl Removable wing Length 59 F-105 Thunderchief basic kit $23900 e P&H Length 73 77-91 Engine No Cheater Hole F-4 Phantom basic kit $59900 HEW 1/7 Scale Twin Engine Aileron/Spoiler Config Length 90 Removable 61 Wings LE/TE flaps Deluse kit DC wood I/B pylons CF kit plus morel Landing gear tires brakes available FLY THE F-100 SUPER SABRE FROM COMPARE OUR RETRACTS TO THEIRS Stainless Struts cut FREEl Stainless Torque Linksl Different strut configurations * 1 Year Limited Warranty GIANT MAIN RETRACTS STANDARD OR 900 ROTAl 30-50 lb aircraft 2 sets 1 Standard 900 minutes 7Q0 1100 retract angle Over-center lock down Nose gear available $27500 pair Wt 15 lbs Complete Air System Axle Installed Parts Service 30 Day Refund SCALE MAIN RETRACTS STANDARD OR 900 ROTATE Fits PICA Skys F-Si 1/5 Yellow A/C Ziroli Bud Nosen plus Choice 91 Plyon Winners Handles 20-25 lb aircraft 8497 retract angle Positive lock up lock down Optional wire struts Nose gear available $19900 pair Wt 22 oz NEW 1/5 SCALE P-Si & SPITFIRE products proudly MADE IN THE USAI TIRED OF DRAGGING YOUR WING TIPS ON ThE GROUND. WV DUCTS FOR VIOJETT OR DYNAMAX PLEASE SPECIFY VERY COMPLETE KIT F100....... $550 VIDEO TAPE MANUAL $20 F100 DEMO TAPE .$10 FREE PITOT POWER$8SSH OFFSET DOOR HINGES B FOR $8 CALL FOR QUANTITY PRICES USHER ENTERPRISES INC 1017 SE FRONTAGE RD BOX 511 NORTH PLAINS OR 97133 503647 0015 booms made next sandwiching length Y32 plywood between two pieces 3/ts balsa makes extremely stiff light boom t/2 ounce Mono Kote covering wrapped around edge joins wing Cut away just enough effect good bond wing Cut away just enough MonoKote wing good glue jointso no bare wood exposed outboard booms booms glued wing using slow-curing epoxy gives time accurately align well wipe away excess glue alcohol thinner stabilizer elevator made U -inch sheet balsa covered MonoKote prior installation cutting slots covering per booms stabilizer now glued booms taking care locate accurately relative wing Note body glued time placed wing reference stabilizer alignment Now look window wing center section planking place bellcrank neutral position Tape pushrod wing cannot move pushrod attached elevator horn elevator temporarily held place hinges glue hinges time clevis adjusted until elevator neutral pushrodlbellcrank maintained neutral position point release tape pushrod check action controls Remove top block rear portion fuselage install aft body around stabilizer taking care put load stabilizer Cut slots MonoKote attach rear fuselage wing Glue top block cut slot fin At this point nose portion use age can pinned place center gravity can determined installing hardware plane nose heavy fuselage can cut center section shortened until proper center gravity approximately t/8 inch front position shown plans weight fillets paint will shift center gravity slightly aft entire plane painted rather covered MonoKote will have guess weight paint its effect center gravity determine nose length will require minimum ballast Glue fuselage slow-curing epoxy using Robart incidence meter conjunction bubble level ensure thrustline parallel wing centerline Glass nose using 3¼-ounce cloth epoxy fin can permanently glued fuselage canopy added complete framing aircraft fuselage can painted per favorite finishing technique model standard dope tissue talc finish used fillthe grain Since commercial modeling dopes good match Continued page 38 30 Model Aviation t day Saturday OUTLAWFAI COM BAT FIrst match starts 1000 am Saturday Entry Fee $700Open Juniors $500 Sponsored Betty Fox Doc Passen Awards prizes third place Special prize highest place Junior Second day Sunday SUPER-SLOW COMBAT Entry Fee $1000Open Juniors $500 Sponsored FOX Manufacturing DoCs Generix Controline Kits Doc Passen Contest Director information call Write PO Box 111 Jasonville IN 47438 Telephone 812 665-3723 2 days Control Line Combat Wood Hand Selected Fiberglass Cowl Complete Plans Parts Hand Cut Instruction Manual Photo Page order kits call 1-800-327-7198 catalog fine kits send $400Idaho Residents Add 5% State Sales Tax Gasoline fueled Produces 3 foot flame will power planes up 228 mph Designed FUN EASY build home shop about 8 hours using materials already have such aerosol spray can combustion chamber Only simple hand tools needed Both high performance jet engines FUN EASY build STEP BY STEP DETAILED FULL SIZE plan sets complete fuel ignition systems JOIN THE JET AGE sending $995 3hp plan set $1295 7hp plan set both sets $2000 JET ENGINE10241 Ridgewood El Paso Texas 79925 AFTER YOU DID ALL THE WORK WHY LET YOUR AIRPLANE DO ALL THE FLYING HumbuglBaron Continued page 30 white MonoKote used automotive lacquer After trim paint canopy can sealed Ditzler acrylic enamel completely fuel proof finish applying final clear coat recommended masking tape placed slightly outside fillet enamel can run around edge fillet seal edge use 3M fine line tape masking gives clean edge leaves no residue removed Remember pull tape off enamel still tacky prevent bonding tape plane allow enamel seal edge During finish workincluding doping applying paper fillets spraying maskingI use ajig attaches engine mounts suspends plane comfortable height Complete paint trim rudder elevator hinging landing gear installation plane held jig FLYING AND TRIMMING Since Humbug has no flaps easier adjust conventional stunter First install ballast required position center gravity shown plans stability standpoint plane will tolerate aft center gravity line tension positive under varied condi tions center gravity aft position shown plans Set leadouts line shown plans Test flights should short lines 62-64 feet x 015 safety Once model trimmed out 65-68 feet optimum Place approximately e weight tip box Adjust elevator horn provide 250 travel direction started four-inch-wide handle As stunters prop selection criti cal amazing little piece wood can affect flight performance prefer wood propsthey readily modified light weight keeps precession minimum get stunt plane pitch gauge must can make blades accurate pitch gauge can also determine exactly way need adjust pitch obtain desired performance general lower pitch greater vertical capability provided engine can turn prop fast enough give adequate airspeed Increasing pitch will increase airspeed will also increase tendency whip up windy conditions Increased diameter also increases vertical capability cost increased whip-up wind Changing blade shape alters power requirements may cause corresponding change airspeed thrust Finding trade-off between diameter pitch blade shape challenge Humbug 91 can save some time giving dimensions best prop date Start Zinger Continued page 129 38 Model Aviation 4PUGNACIOUS PUSSY CAT 1/4 scale Gee Bee Model Y 9017 lbs 3 7 HP PULSE JET ENGINES AVAILABLE BUILD & FLY THE miniMAX VflI IRFI Fl ampion ana- uomputer uesigneoMss serve Urand unampion ultralightPart 103 UltralightEasy construction 1989 Sun-N-Pun Fly-InWood construction TEAM INC 10790-MA Ivy Bluff Rd Bradyville TN 37026615-765-5397 HumbuglBaron Continued page 38 10 x 5 measured pitch 46 5 inches de-pitch true 40 inches stations Next cut diameter 91/2 inches using dial calipers exactly measure blades length carve sweep leading edge starting approximately inch tip ending tip diameter about 1/ inch Balance blade minimize vibration Carefully check flying site presence small rocks tricycle landing gear thin prop turning high rpm can easily broken leading shaft run can damage airframe Set engine hard two-cycle clearly off maximum power 91/2 x 4 prop lap times should 4 5 seconds Check wings level both upright inverted flight wing high steam wing over kettle boiling water until model flies level both upright inverted found wing obviously need steaming based initial flights warp readily detected sighting down trailing edge event steam wing direction indicated attitude plane level flight wing high both directions add tip weight low both ways remove weight Next make sure engine running same both attitudes Checking lap times both upright inverted good way determine tank needs shimming plane slower right-sideup inverted shim tank down until lap times way close equal Once above steps have completed final trimming matter adjusting control travel trade off cornering against loss airspeed adjusting handle width suit needs ended up 220 elevator travel Minor adjustments leadout rake can made adjusting up line improve inside maneuvers down line outside maneuvers Small changes prop diameter 1/s inch time will result tighter slower corners diameter decreased opposite effect diameter increased As high-performance vehicle very small adjustments have significant effects flight character istics 1/s-inch change leadout rake few mph change airspeed will readily noticed handle possible adjustments very wide range performance handling characteristics available flier Humbug will utilize trimming flying skills hand can trimmed fly like trainer other can trimmed deliver performance tax experienced pilot make choice ess Series U-Control Kits Beginners *0 06 wests new Success Series 049 U-Control kits perfect introduction building flying Featuring illustrated step-by-step Success Series construction manuals teach build paint fly models Kits include Micro-Cut Quality parts pre-formed wire parts wheels bellcrank colorful self adhesive markingsqp line Famous Fighters World War II designed use Cox Black Widow engine See products favorite hobby retailer todayl Famous Fighters World War II Models Available #258-Zero *259-Corsairshown #260-Thunderbolt #261 -FockeWuif Midwest Products Co. Inc 4005 Indiana St PO Box 364 Hobart IN 46342 219942-1134 FAX 219 947-23471 992 Midwest Producta CoInc ......... 8055279114 RIC GOODIES 1805 581-5061 cHRAN ST STE 281 SIMI VLY cA 93065 ER & AIRPLANE KITS #3 0 SPANREG GENESIS69$4295 SPEC 2-3 CH RADIO$35 75** STABLE FLYING WING GLIDER FOR HAND LAUNCH HI-START OR CLIFF SOARING MISPAN 100 SQIN 2-3 CH RADIO 06 020 GAS POWERED EASY TO BUILD & FLY DESIGNED FOR MICRO RADIO EQUIPMENT REG $20SSPEC $1885** ERTABLENEW OLD-TIMER RUBBER ROG OR ROW 6 DIE CUT BALSAPLANS INSTRUCTIONS TISSUE CANOPY AND RUBBER MOTOR REG $2995 SPEC $2695** 0 6 PRAIRIE BIRD 50 05 ELECTRIC 0 423 SQIN R/C TRAINER ANYONE CAN BUILD & FLYI $53 95SPEC $4860* SHIPPING INCLUDED IN CONT USA es Cash Cards 6% 0 Sales Tax Cat $1 USA $3 Foreign July1993 129