Radio Control Scale Bob Dolly Wischer NEEDLE VALVES again recent column item about needle valve extensions sparked let ter sketches photos Sam Abdow showing method reaching hidden needle making hole cowl begins making spring approximately 1-in long using A2-in music wire roughly 40 turns wire closely wound mandrel will produce inside diameter Ys end spring soldered over 6-in brass tube cut proper length reach open rear edge cowl solders short 8-32 socket-head Allen screw other tube end music wire spring soldered needle Adjustment needle can now made using Allen wrench aft end tube supported alu minum bracket fastened firewall flat spring engines needle valve body may need bent slightly relax its pressure needle ratchet allow smooth easy oper ation Sam used method Republic P-47 Thunderbolt Mr Mulligan models narrow opening cowl aft end An ideal adjusting tool Du-Bro ball wrench Sams photo P-47 engine installation also depicts another idea can used tightly cowled engine aid cooling has replaced cylinder head planes HB 61 special heat-sink type probably intended use Helicopter could real life saver engine would normally overheat Any number Scale models could use some help engine cooling avoid heartstopping engine seizures midair hot day especially needle valve has inad vertently set couple notches too lean Setting needle peak rpm has led engine failures because propensity engines lean out during flight Some engines sensitive change fuel level fuel tank flight progresses As fuel consumed level drops tank leaning out mixture Muffler pressure applied tank can help will pump system fuel feed Weak links dim distant past used Frank McVeys Monocoupe 90 AL 1 started ikon Northwest kit made lot modifIcations Power OS 240 Cu 4 cylinder 4-cycle engine Model weighs 22 lb spans 96 uses DuPont lacquer over Coverite Maxey Hesters latest Giant 1/3-scale Space Walker R Wingspan 104 uses same engine Monocoupe weighs 215 lb Finish Sig dope over Koverail NEEDLE E OLDER / 1/32 MUSIC WIRE SPRING 1/4 OUTSIDE DIAMETER ABOUT 40 TURNS No 8-32 SOCKET HEAD NYLON STUD MACHINE SCREWFROM No 8-32 SCREW ALUMINUM SUPPORT No 44ri TU4 YWOOZNSERT BRASS 3/I6 uf- SOLDER BASS OR PINE .INTERPLANE STRUT STEEL OR BRASS STUD FROM N0 8-32 SCREW FLAT TAPPED HOLE N. 2-56 / No 8-32 TAP IN PLYWOOD AND IN STRUT Some interesting tips experts Sam Abdow uses homemade extension L conceal needle valve Bob Wischer uses breakaway interplane strut mounts R biplanes prevent serious structural damage model event bad landing notched nylon stud provides weak point fractures easily Theres information both items column month 50 Model Aviation Some 84 Scale entries years Mint Julep contest Rough River runway rubberbands assemble Scale models hope would provide some measure flexibility case bad landing early non-Scale models rubberbands holding components including wing tail surfaces landing gear came era nylon screws expected snap off lose heads protect against major damage problem often used oversized screw wouldnt break away re gardless severity landing forces An other problem inclination screws lose heads surface model beneath screw head wasnt exactly right angles screw axis case weak link considered prudent minimizing damage bad landing Some recent models still use weaklink principle interplane struts biplane example prefer threaded nylon stud 8-32 10-32 size inserted wing reinforced junction plywood stud filed flat portion will extend above wings surface cross-drilled through flat small hex-head screw usually 2-56 size stud can made nylon screw its head removed Scale modelers have active past 20 years will remember output connections Con trolaire Bonner servos ready-made source studs always prone breakage kept few dozen spares stock have found way biplane wings interplane strut connectors bass wood strut has steel brass insert end tapped fastening screw interplane strut has sufficient thickness can drilled tapped end portion steel screw head removed threaded hole length adjustment ideal arrangement setting incidence gles biplane wings relative another short metal stud flattened file crossdrilled tapped 2-56 really firm anchor strut wing drop thin CyA cement exposed threads strut end after adjustment will freeze length joint weak link strut anchor arrangement point nylon stud has necked down bad landing nylon snaps off strut falls free point problem looms remove remains nylon stud imbedded wing drill out carefully retap hole new threaded stud replacement kept turning another drop CyA cement shop its done quite often since landings sometimes bit rough weak link idea can carried another step place weak spot sometimes employ flexible connection example Continued page 145 L details other Zimbabwe Model Products kits call write Full color deluxe catalog $100 -ZIMPRO MARKETING Manufacturers Representatives & importers Fine African Products PO BOX 3076 OAK RIDGE TENNESSEE 37830 Tel 615482-6188 Convenient Size Portable Shade Thata Quick Set Up Change Instantly Give Protection Weather Size 72x 120 60 sq Add units double triple etethe size Porta-Shade available Add units can used trailer awnings patio covers etc Purta-Shade convenient size has no center pole useable space can straddle picnic table model airplane s small vehicle canopy strong heat reflecting waterproof material white top side unique tear proof corner finings no grommets ds almost 7 tall strong t aluminum poles can stand work ptay under comlort wind resistanttested 45MPH Porta-shade very last easy install beach picnic iv mountainsor anywhere want protection hum elements Set up very quick person can about 5 minutes can adjusted easily tilt against sun can set up vertically usa windbreak 4M Co Dept M 814 N Shawnee Dewey OK 74029 Phone 918-534-2244 Master Card Money Orders ks Dealer isqairies invited Sportsman Madel/PFR4-60 $3995 e $3 UPS Economy Modeti EPFR4-60 $3295 e 53 UPS October 1987 51 V Sam Abdows P47 Thunderbolt has HR 61 engine remote needle valve adjustment shown sketch Dummy engine mounts engine bearers Note use cylinder head RC Helicopter en gine aids cooling critical area Zlinn 526 Span 72 Area 900 sq Power 4 stroke ALL BALSA ARF KIT features pre-assembled wood ply fuselage fully sheeted wings stab & rudder epoxy cowl Lexan canopy hardware Lets enjoy outdoorsin comfort U*4Your Little World Comfort Hot Burning Summer Days VOHIhIl DuN WEITINI FUR THE 1[NTENL HEIIDNK MOHELENS lstHnnnoICRM SHOW SWAP SHOP ION * DOOR PRIZES * RAFFLES * PLUS PLUS PLUS I! LIK[ NIL SHOW IliSiJORS CNN ALSO DURJHE WORLD RMOUS CHHHPLINFIGHTERMUSUH 111/2 PRICE SHOW DATES NOV 2 1 st & 22nd 1987SEE THE LATEST IN ALL R/C EQUIPMENT MESA ARIZONA AT THE BEAUTIFUL ES IS H SELLING 5110fF MESA CENTENNIAL HALL 201 N CENTER MANUFACTURERS EXHIBITS usr IN TI4[ FUR CIIHISThIUS SIR UT TIff RAMADA RENAISSANCE HOTEL RESERY AT IONS -800-2-R AM AD TIC DISPLAY COMPET IT ION AIRCRAFT CARS BOATS CALL OR WRITE FOR ADDITIONAL INFORMATION PAUL SCHUTTER 602 533-8536OR 602 g61-39141225N 24TH ST MESA ARIZONA 85203 RC Scale/Wischers Continued page 51 recent models past 15 years wings fastened fuselages 1 -in-long 4-40 machine screws threaded hardwood blocks glued fuselage doublers intern ally could either four screws two screws plus hardwood dowels 4-40 screws may seem too small airplanes weighing up 14 lb have ever broken screws use common hardware-store variety really Grade 2 softest weakest rolled-thread screw manufacturing screw head counter-bored wing head invisible tapped hardwood block inside fuselage spaced away wing surface about screw length unsupported weak flexible spot will bend bad landing per mitting some amount wing shift avoid great damage have extracted some screws after hard bump bent like wet noodles because wing shifted slightly Replace such new screws theyre cheap con tinue flying Sometimes tapped hardwood block fuselage will split through hole another desirable weak spot built have made blocks bass pine maple birch depending upon desired de gree fracture resistance Glue joints Now almost firmly indoctrinated use ubiquitous cyano acrylate CyA cements phases model construction may have forgotten some basic rules forming maximum-strength joints type cement glue early days modeling experience discovered some glue joints failed readily others Wood lain stockpile particularly hardwoods such birch maple engine bear ers servo mounts acquired aged sur face didnt join well white glue Later found didnt matter glue usedan old surface exposed atmosphere acquired patina seemed resistant glue penetration Wood become discolored yellowish tint worst making secure glue joint lesser extent also true old balsa Sanding coarse sandpaper no help whatsoever Coarse sandpaper leaves deep scratches must filled cement reduces contact area between wood cells Sanding finer grade sandpaper No 220 example might have done better job removing aged wood cells effort time spent handsanding made uneconomical method fact prolonged hand-sanding hard-backed block could leave uneven surface hard grain stands high softer surface eroded away condition will prevent close contact between wood cells mating surfaces disc sander 20 convex surface table saw possible alternate way remove old cells Best joints made between freshly cut sur faces maximum strength wood should run through circular saw remove aged surface ordinary ripping blade used set teeth clearance saw kerf newly exposed wood has saw tooth-marks means high points surface will come intimate contact mating piece Glue cement must fill voids between high spots joint again inferior best blade having no set teeth such hollow-ground planer blade several types called satin-cut com bination veneer blades gentle swipe fine sandpaper prepares surface pro duce excellent glue joint same gentle swipe hobby-shop balsa also improves joint strength especially using balse has lain stockpile length time case would believe 25 years Any wood joint can improved removal sawdust sanding residue best possible surface wood should run through jointer having freshly sharpened blade dont know modeler owns circular saw seems standard equip ment modelers workshops However must recognized both tools extremely hazardous machines must treated due respect personally know several modelers have fingers reattached lost forever hobby worth lifetime regret moments carelessness have some highly respected old-time modelers tell us difficult nearly impos sible fasten anything surface made fiberglass cloth polyester resin usual ce ment employed epoxy complaint joint would fracture under low pressure Lack surface preparation culprit behind failures Polyester resin hardens high gloss air also picks up contaminants mold such wax adhesions foam core surfaces indeed difficult bond Breaking gloss sandpaper depth sufficient ex pose glass cloth removal residue will provide good bonding surface engine cowl ancient Emeraude molded fiberglass cowl hold-down bracket fabricated aluminum epoxied interior surface Continued page 149 October 1987 145 MESA RC Scale/Wischers Continued page 145 joint tension truth joint did break time after about five years flying Lake Charles Nats IO0F temperature fastened second time epoxy holds day Castor oil lesser degree lubricants enemy glue joints repairs fiberglass has exposed fuel oil residue must completely removed First scrub methanol dope thinner lacquer thinner ace tone sand away surface bonded sanding drum Dremel tool does best job Fine sanding isnt needed because epoxy fills gaps Finally before mixing epoxy scrub joint area again solvent being careful drag oil prepared area outside oil isnt removed solvent initially sanding ac tion merely imbeds oil workspace solvent cloth should changed often because also becomes oil-contaminated Another glue-joint problem commonly en countered involves unpredictable results tempts join parts made ABS acrylonitrile butadiene styrene either new construction damage repair have tried cementing material ARF model mild success Some joints will fall apart instantly others equivalent weld joint fails probably due contaminants surface whether new old though may appear perfectly clean Preparation cleanliness required especially repairs model fuel has spread over area either direct exposure due wiping model after flight oily cloth Start cleaning joint area solvent such methanol acetone MEK methyl ethyl ketone materials hazardous dont breathe fumes can also ab sorbed through skin MEK especially vicious stuff Use clean wiping cloth facial tissue After few swipes discard cloth fresh certain no residue contaminants remain Roughen surface bonded No 220 aluminum oxide paper wet-sand using No 400 silicon carbide paper water An alternative cleanser kitchen scouring powder water Wash clear water after ward clean area again fresh solvent actual cementing ABS needs overlapped joint using cements intended material have success cements plastic models Glow plugs Several years ago mentioned columns old Champion VG-2 glow plugs served excellently four-stroke engines Unfortunately due attrition sup ply VG-2 now depleted After several seasons usage problem plugs loosening core inside porcelain insulator probably due pounding high cylinder pressure four-stroke new Fox four-stroke shielded plugs have sub stituted performance continues substantially before Champion plugs advantage Scale appearance OS Gemini 120 very closely simulated standard spark plug asked times whether Gemini ignition Except feature can find little difference between Cham pion Fox plugs Bob Dolly Wjscher 5-221 Lapham Peak Rd Delafield WI 53018 RC Giant Scale/de Vries Continied page 55 hes editor invited join NASA Ive intending long time things overlooked press other modeling activities event Stans letter took sent six bucks Bert Dugan secretary treasurer 11090 Phyllis Drive Clio MI 48420 will soon member NASA Any outfit president John Guenther has outstanding met John Scale Internats Paris 84 found him Scale model builders model builder best news Stan Alexanders newsletter confirmation info already passed Wischers FAI has increased weight limits engine sizes little Scale models used international competition fact isnt engine size limit little friends better theyve come up provision al Giant event us build big like contesting world level Specifically new event permits use engines up 61 cu aximum weight 55 lb less fuel maximum surface area event its 7750 sq thats 53 sq ft Thats squares us have ever contemplated Static judging will five meters bit 16 ft Holy Toledo John de Vries 4610 MoffatLn Colorado Springs CO 80915 RC Pylon Racing/Hager Continued page 56 Oliver won race Saturday Phil Bussell coming second Fast time posted Gary Heithold 11406 must say fast time both days Dub Jett posted second fast time second day 11409 Sunday May 31 also 18 entries racing got tougher lots fast airplanes weather almost got us end five rounds Dub Jettwas winner perfect score atie fourth fifth between Dick Ritch newcomer Rick Tocci flyoff really close winner Dick Ritch After flyoff Calcutta held bidding fearsome Dub Jett automati cally race winning Sunday left six others fly off final four spots first race fliers Gary Heithold Dave Layman Bruce Hobbs winner race Dave Layman time 11623 second race Richard Oliver Dick Ritch hit takeoff JP Hanway After long discussion Richard Oliver JP Hanway went final race put final contestants Richard Oliver Dub Jett JP 1-lanway Dave Layman After racing cuts over order finish 1 Dub Jett $288 2 JP Hanway 3 Dave Layman 4 Richard Oliver good time race success lists winners two days First Formula May 30 1 Richard Oliver11951 2 Phil Bussell11978 3 Dub Jett11513 4 Dave Lajman12081 5 JP Hanway12009 6 Bob Greer 12434 7 Hubert Wills12409 8 Dick Ritch 12020 9 Gary Heithold 11406 THE LEADER IN COMPETITION PROPELLERS NEW CYCLE SEiESiGD THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTOGIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MPG OF SELECT HARD MAPLE WOOD WILLNOTFATIGUE LIKE SYNTHETICS FUELPROOFHIGH LUSTER FINISH DIAPITCHPRICE 534149 634149 72833456179 8334568189 845667199 9456677A199 104566/7209 106W8W209 10BEW219 114677778229 IiSW229 11BEW239 1187239 124W279 12SW279 125627w 1356349 1456459 1556659 164N969 16678969 October 1987 149 t5I5tIED & OtWtOPt8 Cli DIA PITCH THP PRICE 12 6677/6 299 13 67/a8379 14 6778 479 1567689 16 678 989 PRO SERIES 3 RC PYLON RACING SERIES 500 DIA PITCH PRICE 75N5/N279 8I 6776 299 SERIES 400C 666777289 9777269 W WIDE BLADE EW EXTRA WIDE N NARROW NEW p TI
Edition: Model Aviation - 1987/10
Page Numbers: 50, 51, 145, 149
Edition: Model Aviation - 1987/10
Page Numbers: 50, 51, 145, 149
Radio Control Scale Bob Dolly Wischer NEEDLE VALVES again recent column item about needle valve extensions sparked let ter sketches photos Sam Abdow showing method reaching hidden needle making hole cowl begins making spring approximately 1-in long using A2-in music wire roughly 40 turns wire closely wound mandrel will produce inside diameter Ys end spring soldered over 6-in brass tube cut proper length reach open rear edge cowl solders short 8-32 socket-head Allen screw other tube end music wire spring soldered needle Adjustment needle can now made using Allen wrench aft end tube supported alu minum bracket fastened firewall flat spring engines needle valve body may need bent slightly relax its pressure needle ratchet allow smooth easy oper ation Sam used method Republic P-47 Thunderbolt Mr Mulligan models narrow opening cowl aft end An ideal adjusting tool Du-Bro ball wrench Sams photo P-47 engine installation also depicts another idea can used tightly cowled engine aid cooling has replaced cylinder head planes HB 61 special heat-sink type probably intended use Helicopter could real life saver engine would normally overheat Any number Scale models could use some help engine cooling avoid heartstopping engine seizures midair hot day especially needle valve has inad vertently set couple notches too lean Setting needle peak rpm has led engine failures because propensity engines lean out during flight Some engines sensitive change fuel level fuel tank flight progresses As fuel consumed level drops tank leaning out mixture Muffler pressure applied tank can help will pump system fuel feed Weak links dim distant past used Frank McVeys Monocoupe 90 AL 1 started ikon Northwest kit made lot modifIcations Power OS 240 Cu 4 cylinder 4-cycle engine Model weighs 22 lb spans 96 uses DuPont lacquer over Coverite Maxey Hesters latest Giant 1/3-scale Space Walker R Wingspan 104 uses same engine Monocoupe weighs 215 lb Finish Sig dope over Koverail NEEDLE E OLDER / 1/32 MUSIC WIRE SPRING 1/4 OUTSIDE DIAMETER ABOUT 40 TURNS No 8-32 SOCKET HEAD NYLON STUD MACHINE SCREWFROM No 8-32 SCREW ALUMINUM SUPPORT No 44ri TU4 YWOOZNSERT BRASS 3/I6 uf- SOLDER BASS OR PINE .INTERPLANE STRUT STEEL OR BRASS STUD FROM N0 8-32 SCREW FLAT TAPPED HOLE N. 2-56 / No 8-32 TAP IN PLYWOOD AND IN STRUT Some interesting tips experts Sam Abdow uses homemade extension L conceal needle valve Bob Wischer uses breakaway interplane strut mounts R biplanes prevent serious structural damage model event bad landing notched nylon stud provides weak point fractures easily Theres information both items column month 50 Model Aviation Some 84 Scale entries years Mint Julep contest Rough River runway rubberbands assemble Scale models hope would provide some measure flexibility case bad landing early non-Scale models rubberbands holding components including wing tail surfaces landing gear came era nylon screws expected snap off lose heads protect against major damage problem often used oversized screw wouldnt break away re gardless severity landing forces An other problem inclination screws lose heads surface model beneath screw head wasnt exactly right angles screw axis case weak link considered prudent minimizing damage bad landing Some recent models still use weaklink principle interplane struts biplane example prefer threaded nylon stud 8-32 10-32 size inserted wing reinforced junction plywood stud filed flat portion will extend above wings surface cross-drilled through flat small hex-head screw usually 2-56 size stud can made nylon screw its head removed Scale modelers have active past 20 years will remember output connections Con trolaire Bonner servos ready-made source studs always prone breakage kept few dozen spares stock have found way biplane wings interplane strut connectors bass wood strut has steel brass insert end tapped fastening screw interplane strut has sufficient thickness can drilled tapped end portion steel screw head removed threaded hole length adjustment ideal arrangement setting incidence gles biplane wings relative another short metal stud flattened file crossdrilled tapped 2-56 really firm anchor strut wing drop thin CyA cement exposed threads strut end after adjustment will freeze length joint weak link strut anchor arrangement point nylon stud has necked down bad landing nylon snaps off strut falls free point problem looms remove remains nylon stud imbedded wing drill out carefully retap hole new threaded stud replacement kept turning another drop CyA cement shop its done quite often since landings sometimes bit rough weak link idea can carried another step place weak spot sometimes employ flexible connection example Continued page 145 L details other Zimbabwe Model Products kits call write Full color deluxe catalog $100 -ZIMPRO MARKETING Manufacturers Representatives & importers Fine African Products PO BOX 3076 OAK RIDGE TENNESSEE 37830 Tel 615482-6188 Convenient Size Portable Shade Thata Quick Set Up Change Instantly Give Protection Weather Size 72x 120 60 sq Add units double triple etethe size Porta-Shade available Add units can used trailer awnings patio covers etc Purta-Shade convenient size has no center pole useable space can straddle picnic table model airplane s small vehicle canopy strong heat reflecting waterproof material white top side unique tear proof corner finings no grommets ds almost 7 tall strong t aluminum poles can stand work ptay under comlort wind resistanttested 45MPH Porta-shade very last easy install beach picnic iv mountainsor anywhere want protection hum elements Set up very quick person can about 5 minutes can adjusted easily tilt against sun can set up vertically usa windbreak 4M Co Dept M 814 N Shawnee Dewey OK 74029 Phone 918-534-2244 Master Card Money Orders ks Dealer isqairies invited Sportsman Madel/PFR4-60 $3995 e $3 UPS Economy Modeti EPFR4-60 $3295 e 53 UPS October 1987 51 V Sam Abdows P47 Thunderbolt has HR 61 engine remote needle valve adjustment shown sketch Dummy engine mounts engine bearers Note use cylinder head RC Helicopter en gine aids cooling critical area Zlinn 526 Span 72 Area 900 sq Power 4 stroke ALL BALSA ARF KIT features pre-assembled wood ply fuselage fully sheeted wings stab & rudder epoxy cowl Lexan canopy hardware Lets enjoy outdoorsin comfort U*4Your Little World Comfort Hot Burning Summer Days VOHIhIl DuN WEITINI FUR THE 1[NTENL HEIIDNK MOHELENS lstHnnnoICRM SHOW SWAP SHOP ION * DOOR PRIZES * RAFFLES * PLUS PLUS PLUS I! LIK[ NIL SHOW IliSiJORS CNN ALSO DURJHE WORLD RMOUS CHHHPLINFIGHTERMUSUH 111/2 PRICE SHOW DATES NOV 2 1 st & 22nd 1987SEE THE LATEST IN ALL R/C EQUIPMENT MESA ARIZONA AT THE BEAUTIFUL ES IS H SELLING 5110fF MESA CENTENNIAL HALL 201 N CENTER MANUFACTURERS EXHIBITS usr IN TI4[ FUR CIIHISThIUS SIR UT TIff RAMADA RENAISSANCE HOTEL RESERY AT IONS -800-2-R AM AD TIC DISPLAY COMPET IT ION AIRCRAFT CARS BOATS CALL OR WRITE FOR ADDITIONAL INFORMATION PAUL SCHUTTER 602 533-8536OR 602 g61-39141225N 24TH ST MESA ARIZONA 85203 RC Scale/Wischers Continued page 51 recent models past 15 years wings fastened fuselages 1 -in-long 4-40 machine screws threaded hardwood blocks glued fuselage doublers intern ally could either four screws two screws plus hardwood dowels 4-40 screws may seem too small airplanes weighing up 14 lb have ever broken screws use common hardware-store variety really Grade 2 softest weakest rolled-thread screw manufacturing screw head counter-bored wing head invisible tapped hardwood block inside fuselage spaced away wing surface about screw length unsupported weak flexible spot will bend bad landing per mitting some amount wing shift avoid great damage have extracted some screws after hard bump bent like wet noodles because wing shifted slightly Replace such new screws theyre cheap con tinue flying Sometimes tapped hardwood block fuselage will split through hole another desirable weak spot built have made blocks bass pine maple birch depending upon desired de gree fracture resistance Glue joints Now almost firmly indoctrinated use ubiquitous cyano acrylate CyA cements phases model construction may have forgotten some basic rules forming maximum-strength joints type cement glue early days modeling experience discovered some glue joints failed readily others Wood lain stockpile particularly hardwoods such birch maple engine bear ers servo mounts acquired aged sur face didnt join well white glue Later found didnt matter glue usedan old surface exposed atmosphere acquired patina seemed resistant glue penetration Wood become discolored yellowish tint worst making secure glue joint lesser extent also true old balsa Sanding coarse sandpaper no help whatsoever Coarse sandpaper leaves deep scratches must filled cement reduces contact area between wood cells Sanding finer grade sandpaper No 220 example might have done better job removing aged wood cells effort time spent handsanding made uneconomical method fact prolonged hand-sanding hard-backed block could leave uneven surface hard grain stands high softer surface eroded away condition will prevent close contact between wood cells mating surfaces disc sander 20 convex surface table saw possible alternate way remove old cells Best joints made between freshly cut sur faces maximum strength wood should run through circular saw remove aged surface ordinary ripping blade used set teeth clearance saw kerf newly exposed wood has saw tooth-marks means high points surface will come intimate contact mating piece Glue cement must fill voids between high spots joint again inferior best blade having no set teeth such hollow-ground planer blade several types called satin-cut com bination veneer blades gentle swipe fine sandpaper prepares surface pro duce excellent glue joint same gentle swipe hobby-shop balsa also improves joint strength especially using balse has lain stockpile length time case would believe 25 years Any wood joint can improved removal sawdust sanding residue best possible surface wood should run through jointer having freshly sharpened blade dont know modeler owns circular saw seems standard equip ment modelers workshops However must recognized both tools extremely hazardous machines must treated due respect personally know several modelers have fingers reattached lost forever hobby worth lifetime regret moments carelessness have some highly respected old-time modelers tell us difficult nearly impos sible fasten anything surface made fiberglass cloth polyester resin usual ce ment employed epoxy complaint joint would fracture under low pressure Lack surface preparation culprit behind failures Polyester resin hardens high gloss air also picks up contaminants mold such wax adhesions foam core surfaces indeed difficult bond Breaking gloss sandpaper depth sufficient ex pose glass cloth removal residue will provide good bonding surface engine cowl ancient Emeraude molded fiberglass cowl hold-down bracket fabricated aluminum epoxied interior surface Continued page 149 October 1987 145 MESA RC Scale/Wischers Continued page 145 joint tension truth joint did break time after about five years flying Lake Charles Nats IO0F temperature fastened second time epoxy holds day Castor oil lesser degree lubricants enemy glue joints repairs fiberglass has exposed fuel oil residue must completely removed First scrub methanol dope thinner lacquer thinner ace tone sand away surface bonded sanding drum Dremel tool does best job Fine sanding isnt needed because epoxy fills gaps Finally before mixing epoxy scrub joint area again solvent being careful drag oil prepared area outside oil isnt removed solvent initially sanding ac tion merely imbeds oil workspace solvent cloth should changed often because also becomes oil-contaminated Another glue-joint problem commonly en countered involves unpredictable results tempts join parts made ABS acrylonitrile butadiene styrene either new construction damage repair have tried cementing material ARF model mild success Some joints will fall apart instantly others equivalent weld joint fails probably due contaminants surface whether new old though may appear perfectly clean Preparation cleanliness required especially repairs model fuel has spread over area either direct exposure due wiping model after flight oily cloth Start cleaning joint area solvent such methanol acetone MEK methyl ethyl ketone materials hazardous dont breathe fumes can also ab sorbed through skin MEK especially vicious stuff Use clean wiping cloth facial tissue After few swipes discard cloth fresh certain no residue contaminants remain Roughen surface bonded No 220 aluminum oxide paper wet-sand using No 400 silicon carbide paper water An alternative cleanser kitchen scouring powder water Wash clear water after ward clean area again fresh solvent actual cementing ABS needs overlapped joint using cements intended material have success cements plastic models Glow plugs Several years ago mentioned columns old Champion VG-2 glow plugs served excellently four-stroke engines Unfortunately due attrition sup ply VG-2 now depleted After several seasons usage problem plugs loosening core inside porcelain insulator probably due pounding high cylinder pressure four-stroke new Fox four-stroke shielded plugs have sub stituted performance continues substantially before Champion plugs advantage Scale appearance OS Gemini 120 very closely simulated standard spark plug asked times whether Gemini ignition Except feature can find little difference between Cham pion Fox plugs Bob Dolly Wjscher 5-221 Lapham Peak Rd Delafield WI 53018 RC Giant Scale/de Vries Continied page 55 hes editor invited join NASA Ive intending long time things overlooked press other modeling activities event Stans letter took sent six bucks Bert Dugan secretary treasurer 11090 Phyllis Drive Clio MI 48420 will soon member NASA Any outfit president John Guenther has outstanding met John Scale Internats Paris 84 found him Scale model builders model builder best news Stan Alexanders newsletter confirmation info already passed Wischers FAI has increased weight limits engine sizes little Scale models used international competition fact isnt engine size limit little friends better theyve come up provision al Giant event us build big like contesting world level Specifically new event permits use engines up 61 cu aximum weight 55 lb less fuel maximum surface area event its 7750 sq thats 53 sq ft Thats squares us have ever contemplated Static judging will five meters bit 16 ft Holy Toledo John de Vries 4610 MoffatLn Colorado Springs CO 80915 RC Pylon Racing/Hager Continued page 56 Oliver won race Saturday Phil Bussell coming second Fast time posted Gary Heithold 11406 must say fast time both days Dub Jett posted second fast time second day 11409 Sunday May 31 also 18 entries racing got tougher lots fast airplanes weather almost got us end five rounds Dub Jettwas winner perfect score atie fourth fifth between Dick Ritch newcomer Rick Tocci flyoff really close winner Dick Ritch After flyoff Calcutta held bidding fearsome Dub Jett automati cally race winning Sunday left six others fly off final four spots first race fliers Gary Heithold Dave Layman Bruce Hobbs winner race Dave Layman time 11623 second race Richard Oliver Dick Ritch hit takeoff JP Hanway After long discussion Richard Oliver JP Hanway went final race put final contestants Richard Oliver Dub Jett JP 1-lanway Dave Layman After racing cuts over order finish 1 Dub Jett $288 2 JP Hanway 3 Dave Layman 4 Richard Oliver good time race success lists winners two days First Formula May 30 1 Richard Oliver11951 2 Phil Bussell11978 3 Dub Jett11513 4 Dave Lajman12081 5 JP Hanway12009 6 Bob Greer 12434 7 Hubert Wills12409 8 Dick Ritch 12020 9 Gary Heithold 11406 THE LEADER IN COMPETITION PROPELLERS NEW CYCLE SEiESiGD THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTOGIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MPG OF SELECT HARD MAPLE WOOD WILLNOTFATIGUE LIKE SYNTHETICS FUELPROOFHIGH LUSTER FINISH DIAPITCHPRICE 534149 634149 72833456179 8334568189 845667199 9456677A199 104566/7209 106W8W209 10BEW219 114677778229 IiSW229 11BEW239 1187239 124W279 12SW279 125627w 1356349 1456459 1556659 164N969 16678969 October 1987 149 t5I5tIED & OtWtOPt8 Cli DIA PITCH THP PRICE 12 6677/6 299 13 67/a8379 14 6778 479 1567689 16 678 989 PRO SERIES 3 RC PYLON RACING SERIES 500 DIA PITCH PRICE 75N5/N279 8I 6776 299 SERIES 400C 666777289 9777269 W WIDE BLADE EW EXTRA WIDE N NARROW NEW p TI
Edition: Model Aviation - 1987/10
Page Numbers: 50, 51, 145, 149
Radio Control Scale Bob Dolly Wischer NEEDLE VALVES again recent column item about needle valve extensions sparked let ter sketches photos Sam Abdow showing method reaching hidden needle making hole cowl begins making spring approximately 1-in long using A2-in music wire roughly 40 turns wire closely wound mandrel will produce inside diameter Ys end spring soldered over 6-in brass tube cut proper length reach open rear edge cowl solders short 8-32 socket-head Allen screw other tube end music wire spring soldered needle Adjustment needle can now made using Allen wrench aft end tube supported alu minum bracket fastened firewall flat spring engines needle valve body may need bent slightly relax its pressure needle ratchet allow smooth easy oper ation Sam used method Republic P-47 Thunderbolt Mr Mulligan models narrow opening cowl aft end An ideal adjusting tool Du-Bro ball wrench Sams photo P-47 engine installation also depicts another idea can used tightly cowled engine aid cooling has replaced cylinder head planes HB 61 special heat-sink type probably intended use Helicopter could real life saver engine would normally overheat Any number Scale models could use some help engine cooling avoid heartstopping engine seizures midair hot day especially needle valve has inad vertently set couple notches too lean Setting needle peak rpm has led engine failures because propensity engines lean out during flight Some engines sensitive change fuel level fuel tank flight progresses As fuel consumed level drops tank leaning out mixture Muffler pressure applied tank can help will pump system fuel feed Weak links dim distant past used Frank McVeys Monocoupe 90 AL 1 started ikon Northwest kit made lot modifIcations Power OS 240 Cu 4 cylinder 4-cycle engine Model weighs 22 lb spans 96 uses DuPont lacquer over Coverite Maxey Hesters latest Giant 1/3-scale Space Walker R Wingspan 104 uses same engine Monocoupe weighs 215 lb Finish Sig dope over Koverail NEEDLE E OLDER / 1/32 MUSIC WIRE SPRING 1/4 OUTSIDE DIAMETER ABOUT 40 TURNS No 8-32 SOCKET HEAD NYLON STUD MACHINE SCREWFROM No 8-32 SCREW ALUMINUM SUPPORT No 44ri TU4 YWOOZNSERT BRASS 3/I6 uf- SOLDER BASS OR PINE .INTERPLANE STRUT STEEL OR BRASS STUD FROM N0 8-32 SCREW FLAT TAPPED HOLE N. 2-56 / No 8-32 TAP IN PLYWOOD AND IN STRUT Some interesting tips experts Sam Abdow uses homemade extension L conceal needle valve Bob Wischer uses breakaway interplane strut mounts R biplanes prevent serious structural damage model event bad landing notched nylon stud provides weak point fractures easily Theres information both items column month 50 Model Aviation Some 84 Scale entries years Mint Julep contest Rough River runway rubberbands assemble Scale models hope would provide some measure flexibility case bad landing early non-Scale models rubberbands holding components including wing tail surfaces landing gear came era nylon screws expected snap off lose heads protect against major damage problem often used oversized screw wouldnt break away re gardless severity landing forces An other problem inclination screws lose heads surface model beneath screw head wasnt exactly right angles screw axis case weak link considered prudent minimizing damage bad landing Some recent models still use weaklink principle interplane struts biplane example prefer threaded nylon stud 8-32 10-32 size inserted wing reinforced junction plywood stud filed flat portion will extend above wings surface cross-drilled through flat small hex-head screw usually 2-56 size stud can made nylon screw its head removed Scale modelers have active past 20 years will remember output connections Con trolaire Bonner servos ready-made source studs always prone breakage kept few dozen spares stock have found way biplane wings interplane strut connectors bass wood strut has steel brass insert end tapped fastening screw interplane strut has sufficient thickness can drilled tapped end portion steel screw head removed threaded hole length adjustment ideal arrangement setting incidence gles biplane wings relative another short metal stud flattened file crossdrilled tapped 2-56 really firm anchor strut wing drop thin CyA cement exposed threads strut end after adjustment will freeze length joint weak link strut anchor arrangement point nylon stud has necked down bad landing nylon snaps off strut falls free point problem looms remove remains nylon stud imbedded wing drill out carefully retap hole new threaded stud replacement kept turning another drop CyA cement shop its done quite often since landings sometimes bit rough weak link idea can carried another step place weak spot sometimes employ flexible connection example Continued page 145 L details other Zimbabwe Model Products kits call write Full color deluxe catalog $100 -ZIMPRO MARKETING Manufacturers Representatives & importers Fine African Products PO BOX 3076 OAK RIDGE TENNESSEE 37830 Tel 615482-6188 Convenient Size Portable Shade Thata Quick Set Up Change Instantly Give Protection Weather Size 72x 120 60 sq Add units double triple etethe size Porta-Shade available Add units can used trailer awnings patio covers etc Purta-Shade convenient size has no center pole useable space can straddle picnic table model airplane s small vehicle canopy strong heat reflecting waterproof material white top side unique tear proof corner finings no grommets ds almost 7 tall strong t aluminum poles can stand work ptay under comlort wind resistanttested 45MPH Porta-shade very last easy install beach picnic iv mountainsor anywhere want protection hum elements Set up very quick person can about 5 minutes can adjusted easily tilt against sun can set up vertically usa windbreak 4M Co Dept M 814 N Shawnee Dewey OK 74029 Phone 918-534-2244 Master Card Money Orders ks Dealer isqairies invited Sportsman Madel/PFR4-60 $3995 e $3 UPS Economy Modeti EPFR4-60 $3295 e 53 UPS October 1987 51 V Sam Abdows P47 Thunderbolt has HR 61 engine remote needle valve adjustment shown sketch Dummy engine mounts engine bearers Note use cylinder head RC Helicopter en gine aids cooling critical area Zlinn 526 Span 72 Area 900 sq Power 4 stroke ALL BALSA ARF KIT features pre-assembled wood ply fuselage fully sheeted wings stab & rudder epoxy cowl Lexan canopy hardware Lets enjoy outdoorsin comfort U*4Your Little World Comfort Hot Burning Summer Days VOHIhIl DuN WEITINI FUR THE 1[NTENL HEIIDNK MOHELENS lstHnnnoICRM SHOW SWAP SHOP ION * DOOR PRIZES * RAFFLES * PLUS PLUS PLUS I! LIK[ NIL SHOW IliSiJORS CNN ALSO DURJHE WORLD RMOUS CHHHPLINFIGHTERMUSUH 111/2 PRICE SHOW DATES NOV 2 1 st & 22nd 1987SEE THE LATEST IN ALL R/C EQUIPMENT MESA ARIZONA AT THE BEAUTIFUL ES IS H SELLING 5110fF MESA CENTENNIAL HALL 201 N CENTER MANUFACTURERS EXHIBITS usr IN TI4[ FUR CIIHISThIUS SIR UT TIff RAMADA RENAISSANCE HOTEL RESERY AT IONS -800-2-R AM AD TIC DISPLAY COMPET IT ION AIRCRAFT CARS BOATS CALL OR WRITE FOR ADDITIONAL INFORMATION PAUL SCHUTTER 602 533-8536OR 602 g61-39141225N 24TH ST MESA ARIZONA 85203 RC Scale/Wischers Continued page 51 recent models past 15 years wings fastened fuselages 1 -in-long 4-40 machine screws threaded hardwood blocks glued fuselage doublers intern ally could either four screws two screws plus hardwood dowels 4-40 screws may seem too small airplanes weighing up 14 lb have ever broken screws use common hardware-store variety really Grade 2 softest weakest rolled-thread screw manufacturing screw head counter-bored wing head invisible tapped hardwood block inside fuselage spaced away wing surface about screw length unsupported weak flexible spot will bend bad landing per mitting some amount wing shift avoid great damage have extracted some screws after hard bump bent like wet noodles because wing shifted slightly Replace such new screws theyre cheap con tinue flying Sometimes tapped hardwood block fuselage will split through hole another desirable weak spot built have made blocks bass pine maple birch depending upon desired de gree fracture resistance Glue joints Now almost firmly indoctrinated use ubiquitous cyano acrylate CyA cements phases model construction may have forgotten some basic rules forming maximum-strength joints type cement glue early days modeling experience discovered some glue joints failed readily others Wood lain stockpile particularly hardwoods such birch maple engine bear ers servo mounts acquired aged sur face didnt join well white glue Later found didnt matter glue usedan old surface exposed atmosphere acquired patina seemed resistant glue penetration Wood become discolored yellowish tint worst making secure glue joint lesser extent also true old balsa Sanding coarse sandpaper no help whatsoever Coarse sandpaper leaves deep scratches must filled cement reduces contact area between wood cells Sanding finer grade sandpaper No 220 example might have done better job removing aged wood cells effort time spent handsanding made uneconomical method fact prolonged hand-sanding hard-backed block could leave uneven surface hard grain stands high softer surface eroded away condition will prevent close contact between wood cells mating surfaces disc sander 20 convex surface table saw possible alternate way remove old cells Best joints made between freshly cut sur faces maximum strength wood should run through circular saw remove aged surface ordinary ripping blade used set teeth clearance saw kerf newly exposed wood has saw tooth-marks means high points surface will come intimate contact mating piece Glue cement must fill voids between high spots joint again inferior best blade having no set teeth such hollow-ground planer blade several types called satin-cut com bination veneer blades gentle swipe fine sandpaper prepares surface pro duce excellent glue joint same gentle swipe hobby-shop balsa also improves joint strength especially using balse has lain stockpile length time case would believe 25 years Any wood joint can improved removal sawdust sanding residue best possible surface wood should run through jointer having freshly sharpened blade dont know modeler owns circular saw seems standard equip ment modelers workshops However must recognized both tools extremely hazardous machines must treated due respect personally know several modelers have fingers reattached lost forever hobby worth lifetime regret moments carelessness have some highly respected old-time modelers tell us difficult nearly impos sible fasten anything surface made fiberglass cloth polyester resin usual ce ment employed epoxy complaint joint would fracture under low pressure Lack surface preparation culprit behind failures Polyester resin hardens high gloss air also picks up contaminants mold such wax adhesions foam core surfaces indeed difficult bond Breaking gloss sandpaper depth sufficient ex pose glass cloth removal residue will provide good bonding surface engine cowl ancient Emeraude molded fiberglass cowl hold-down bracket fabricated aluminum epoxied interior surface Continued page 149 October 1987 145 MESA RC Scale/Wischers Continued page 145 joint tension truth joint did break time after about five years flying Lake Charles Nats IO0F temperature fastened second time epoxy holds day Castor oil lesser degree lubricants enemy glue joints repairs fiberglass has exposed fuel oil residue must completely removed First scrub methanol dope thinner lacquer thinner ace tone sand away surface bonded sanding drum Dremel tool does best job Fine sanding isnt needed because epoxy fills gaps Finally before mixing epoxy scrub joint area again solvent being careful drag oil prepared area outside oil isnt removed solvent initially sanding ac tion merely imbeds oil workspace solvent cloth should changed often because also becomes oil-contaminated Another glue-joint problem commonly en countered involves unpredictable results tempts join parts made ABS acrylonitrile butadiene styrene either new construction damage repair have tried cementing material ARF model mild success Some joints will fall apart instantly others equivalent weld joint fails probably due contaminants surface whether new old though may appear perfectly clean Preparation cleanliness required especially repairs model fuel has spread over area either direct exposure due wiping model after flight oily cloth Start cleaning joint area solvent such methanol acetone MEK methyl ethyl ketone materials hazardous dont breathe fumes can also ab sorbed through skin MEK especially vicious stuff Use clean wiping cloth facial tissue After few swipes discard cloth fresh certain no residue contaminants remain Roughen surface bonded No 220 aluminum oxide paper wet-sand using No 400 silicon carbide paper water An alternative cleanser kitchen scouring powder water Wash clear water after ward clean area again fresh solvent actual cementing ABS needs overlapped joint using cements intended material have success cements plastic models Glow plugs Several years ago mentioned columns old Champion VG-2 glow plugs served excellently four-stroke engines Unfortunately due attrition sup ply VG-2 now depleted After several seasons usage problem plugs loosening core inside porcelain insulator probably due pounding high cylinder pressure four-stroke new Fox four-stroke shielded plugs have sub stituted performance continues substantially before Champion plugs advantage Scale appearance OS Gemini 120 very closely simulated standard spark plug asked times whether Gemini ignition Except feature can find little difference between Cham pion Fox plugs Bob Dolly Wjscher 5-221 Lapham Peak Rd Delafield WI 53018 RC Giant Scale/de Vries Continied page 55 hes editor invited join NASA Ive intending long time things overlooked press other modeling activities event Stans letter took sent six bucks Bert Dugan secretary treasurer 11090 Phyllis Drive Clio MI 48420 will soon member NASA Any outfit president John Guenther has outstanding met John Scale Internats Paris 84 found him Scale model builders model builder best news Stan Alexanders newsletter confirmation info already passed Wischers FAI has increased weight limits engine sizes little Scale models used international competition fact isnt engine size limit little friends better theyve come up provision al Giant event us build big like contesting world level Specifically new event permits use engines up 61 cu aximum weight 55 lb less fuel maximum surface area event its 7750 sq thats 53 sq ft Thats squares us have ever contemplated Static judging will five meters bit 16 ft Holy Toledo John de Vries 4610 MoffatLn Colorado Springs CO 80915 RC Pylon Racing/Hager Continued page 56 Oliver won race Saturday Phil Bussell coming second Fast time posted Gary Heithold 11406 must say fast time both days Dub Jett posted second fast time second day 11409 Sunday May 31 also 18 entries racing got tougher lots fast airplanes weather almost got us end five rounds Dub Jettwas winner perfect score atie fourth fifth between Dick Ritch newcomer Rick Tocci flyoff really close winner Dick Ritch After flyoff Calcutta held bidding fearsome Dub Jett automati cally race winning Sunday left six others fly off final four spots first race fliers Gary Heithold Dave Layman Bruce Hobbs winner race Dave Layman time 11623 second race Richard Oliver Dick Ritch hit takeoff JP Hanway After long discussion Richard Oliver JP Hanway went final race put final contestants Richard Oliver Dub Jett JP 1-lanway Dave Layman After racing cuts over order finish 1 Dub Jett $288 2 JP Hanway 3 Dave Layman 4 Richard Oliver good time race success lists winners two days First Formula May 30 1 Richard Oliver11951 2 Phil Bussell11978 3 Dub Jett11513 4 Dave Lajman12081 5 JP Hanway12009 6 Bob Greer 12434 7 Hubert Wills12409 8 Dick Ritch 12020 9 Gary Heithold 11406 THE LEADER IN COMPETITION PROPELLERS NEW CYCLE SEiESiGD THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTOGIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MPG OF SELECT HARD MAPLE WOOD WILLNOTFATIGUE LIKE SYNTHETICS FUELPROOFHIGH LUSTER FINISH DIAPITCHPRICE 534149 634149 72833456179 8334568189 845667199 9456677A199 104566/7209 106W8W209 10BEW219 114677778229 IiSW229 11BEW239 1187239 124W279 12SW279 125627w 1356349 1456459 1556659 164N969 16678969 October 1987 149 t5I5tIED & OtWtOPt8 Cli DIA PITCH THP PRICE 12 6677/6 299 13 67/a8379 14 6778 479 1567689 16 678 989 PRO SERIES 3 RC PYLON RACING SERIES 500 DIA PITCH PRICE 75N5/N279 8I 6776 299 SERIES 400C 666777289 9777269 W WIDE BLADE EW EXTRA WIDE N NARROW NEW p TI
Edition: Model Aviation - 1987/10
Page Numbers: 50, 51, 145, 149
Radio Control Scale Bob Dolly Wischer NEEDLE VALVES again recent column item about needle valve extensions sparked let ter sketches photos Sam Abdow showing method reaching hidden needle making hole cowl begins making spring approximately 1-in long using A2-in music wire roughly 40 turns wire closely wound mandrel will produce inside diameter Ys end spring soldered over 6-in brass tube cut proper length reach open rear edge cowl solders short 8-32 socket-head Allen screw other tube end music wire spring soldered needle Adjustment needle can now made using Allen wrench aft end tube supported alu minum bracket fastened firewall flat spring engines needle valve body may need bent slightly relax its pressure needle ratchet allow smooth easy oper ation Sam used method Republic P-47 Thunderbolt Mr Mulligan models narrow opening cowl aft end An ideal adjusting tool Du-Bro ball wrench Sams photo P-47 engine installation also depicts another idea can used tightly cowled engine aid cooling has replaced cylinder head planes HB 61 special heat-sink type probably intended use Helicopter could real life saver engine would normally overheat Any number Scale models could use some help engine cooling avoid heartstopping engine seizures midair hot day especially needle valve has inad vertently set couple notches too lean Setting needle peak rpm has led engine failures because propensity engines lean out during flight Some engines sensitive change fuel level fuel tank flight progresses As fuel consumed level drops tank leaning out mixture Muffler pressure applied tank can help will pump system fuel feed Weak links dim distant past used Frank McVeys Monocoupe 90 AL 1 started ikon Northwest kit made lot modifIcations Power OS 240 Cu 4 cylinder 4-cycle engine Model weighs 22 lb spans 96 uses DuPont lacquer over Coverite Maxey Hesters latest Giant 1/3-scale Space Walker R Wingspan 104 uses same engine Monocoupe weighs 215 lb Finish Sig dope over Koverail NEEDLE E OLDER / 1/32 MUSIC WIRE SPRING 1/4 OUTSIDE DIAMETER ABOUT 40 TURNS No 8-32 SOCKET HEAD NYLON STUD MACHINE SCREWFROM No 8-32 SCREW ALUMINUM SUPPORT No 44ri TU4 YWOOZNSERT BRASS 3/I6 uf- SOLDER BASS OR PINE .INTERPLANE STRUT STEEL OR BRASS STUD FROM N0 8-32 SCREW FLAT TAPPED HOLE N. 2-56 / No 8-32 TAP IN PLYWOOD AND IN STRUT Some interesting tips experts Sam Abdow uses homemade extension L conceal needle valve Bob Wischer uses breakaway interplane strut mounts R biplanes prevent serious structural damage model event bad landing notched nylon stud provides weak point fractures easily Theres information both items column month 50 Model Aviation Some 84 Scale entries years Mint Julep contest Rough River runway rubberbands assemble Scale models hope would provide some measure flexibility case bad landing early non-Scale models rubberbands holding components including wing tail surfaces landing gear came era nylon screws expected snap off lose heads protect against major damage problem often used oversized screw wouldnt break away re gardless severity landing forces An other problem inclination screws lose heads surface model beneath screw head wasnt exactly right angles screw axis case weak link considered prudent minimizing damage bad landing Some recent models still use weaklink principle interplane struts biplane example prefer threaded nylon stud 8-32 10-32 size inserted wing reinforced junction plywood stud filed flat portion will extend above wings surface cross-drilled through flat small hex-head screw usually 2-56 size stud can made nylon screw its head removed Scale modelers have active past 20 years will remember output connections Con trolaire Bonner servos ready-made source studs always prone breakage kept few dozen spares stock have found way biplane wings interplane strut connectors bass wood strut has steel brass insert end tapped fastening screw interplane strut has sufficient thickness can drilled tapped end portion steel screw head removed threaded hole length adjustment ideal arrangement setting incidence gles biplane wings relative another short metal stud flattened file crossdrilled tapped 2-56 really firm anchor strut wing drop thin CyA cement exposed threads strut end after adjustment will freeze length joint weak link strut anchor arrangement point nylon stud has necked down bad landing nylon snaps off strut falls free point problem looms remove remains nylon stud imbedded wing drill out carefully retap hole new threaded stud replacement kept turning another drop CyA cement shop its done quite often since landings sometimes bit rough weak link idea can carried another step place weak spot sometimes employ flexible connection example Continued page 145 L details other Zimbabwe Model Products kits call write Full color deluxe catalog $100 -ZIMPRO MARKETING Manufacturers Representatives & importers Fine African Products PO BOX 3076 OAK RIDGE TENNESSEE 37830 Tel 615482-6188 Convenient Size Portable Shade Thata Quick Set Up Change Instantly Give Protection Weather Size 72x 120 60 sq Add units double triple etethe size Porta-Shade available Add units can used trailer awnings patio covers etc Purta-Shade convenient size has no center pole useable space can straddle picnic table model airplane s small vehicle canopy strong heat reflecting waterproof material white top side unique tear proof corner finings no grommets ds almost 7 tall strong t aluminum poles can stand work ptay under comlort wind resistanttested 45MPH Porta-shade very last easy install beach picnic iv mountainsor anywhere want protection hum elements Set up very quick person can about 5 minutes can adjusted easily tilt against sun can set up vertically usa windbreak 4M Co Dept M 814 N Shawnee Dewey OK 74029 Phone 918-534-2244 Master Card Money Orders ks Dealer isqairies invited Sportsman Madel/PFR4-60 $3995 e $3 UPS Economy Modeti EPFR4-60 $3295 e 53 UPS October 1987 51 V Sam Abdows P47 Thunderbolt has HR 61 engine remote needle valve adjustment shown sketch Dummy engine mounts engine bearers Note use cylinder head RC Helicopter en gine aids cooling critical area Zlinn 526 Span 72 Area 900 sq Power 4 stroke ALL BALSA ARF KIT features pre-assembled wood ply fuselage fully sheeted wings stab & rudder epoxy cowl Lexan canopy hardware Lets enjoy outdoorsin comfort U*4Your Little World Comfort Hot Burning Summer Days VOHIhIl DuN WEITINI FUR THE 1[NTENL HEIIDNK MOHELENS lstHnnnoICRM SHOW SWAP SHOP ION * DOOR PRIZES * RAFFLES * PLUS PLUS PLUS I! LIK[ NIL SHOW IliSiJORS CNN ALSO DURJHE WORLD RMOUS CHHHPLINFIGHTERMUSUH 111/2 PRICE SHOW DATES NOV 2 1 st & 22nd 1987SEE THE LATEST IN ALL R/C EQUIPMENT MESA ARIZONA AT THE BEAUTIFUL ES IS H SELLING 5110fF MESA CENTENNIAL HALL 201 N CENTER MANUFACTURERS EXHIBITS usr IN TI4[ FUR CIIHISThIUS SIR UT TIff RAMADA RENAISSANCE HOTEL RESERY AT IONS -800-2-R AM AD TIC DISPLAY COMPET IT ION AIRCRAFT CARS BOATS CALL OR WRITE FOR ADDITIONAL INFORMATION PAUL SCHUTTER 602 533-8536OR 602 g61-39141225N 24TH ST MESA ARIZONA 85203 RC Scale/Wischers Continued page 51 recent models past 15 years wings fastened fuselages 1 -in-long 4-40 machine screws threaded hardwood blocks glued fuselage doublers intern ally could either four screws two screws plus hardwood dowels 4-40 screws may seem too small airplanes weighing up 14 lb have ever broken screws use common hardware-store variety really Grade 2 softest weakest rolled-thread screw manufacturing screw head counter-bored wing head invisible tapped hardwood block inside fuselage spaced away wing surface about screw length unsupported weak flexible spot will bend bad landing per mitting some amount wing shift avoid great damage have extracted some screws after hard bump bent like wet noodles because wing shifted slightly Replace such new screws theyre cheap con tinue flying Sometimes tapped hardwood block fuselage will split through hole another desirable weak spot built have made blocks bass pine maple birch depending upon desired de gree fracture resistance Glue joints Now almost firmly indoctrinated use ubiquitous cyano acrylate CyA cements phases model construction may have forgotten some basic rules forming maximum-strength joints type cement glue early days modeling experience discovered some glue joints failed readily others Wood lain stockpile particularly hardwoods such birch maple engine bear ers servo mounts acquired aged sur face didnt join well white glue Later found didnt matter glue usedan old surface exposed atmosphere acquired patina seemed resistant glue penetration Wood become discolored yellowish tint worst making secure glue joint lesser extent also true old balsa Sanding coarse sandpaper no help whatsoever Coarse sandpaper leaves deep scratches must filled cement reduces contact area between wood cells Sanding finer grade sandpaper No 220 example might have done better job removing aged wood cells effort time spent handsanding made uneconomical method fact prolonged hand-sanding hard-backed block could leave uneven surface hard grain stands high softer surface eroded away condition will prevent close contact between wood cells mating surfaces disc sander 20 convex surface table saw possible alternate way remove old cells Best joints made between freshly cut sur faces maximum strength wood should run through circular saw remove aged surface ordinary ripping blade used set teeth clearance saw kerf newly exposed wood has saw tooth-marks means high points surface will come intimate contact mating piece Glue cement must fill voids between high spots joint again inferior best blade having no set teeth such hollow-ground planer blade several types called satin-cut com bination veneer blades gentle swipe fine sandpaper prepares surface pro duce excellent glue joint same gentle swipe hobby-shop balsa also improves joint strength especially using balse has lain stockpile length time case would believe 25 years Any wood joint can improved removal sawdust sanding residue best possible surface wood should run through jointer having freshly sharpened blade dont know modeler owns circular saw seems standard equip ment modelers workshops However must recognized both tools extremely hazardous machines must treated due respect personally know several modelers have fingers reattached lost forever hobby worth lifetime regret moments carelessness have some highly respected old-time modelers tell us difficult nearly impos sible fasten anything surface made fiberglass cloth polyester resin usual ce ment employed epoxy complaint joint would fracture under low pressure Lack surface preparation culprit behind failures Polyester resin hardens high gloss air also picks up contaminants mold such wax adhesions foam core surfaces indeed difficult bond Breaking gloss sandpaper depth sufficient ex pose glass cloth removal residue will provide good bonding surface engine cowl ancient Emeraude molded fiberglass cowl hold-down bracket fabricated aluminum epoxied interior surface Continued page 149 October 1987 145 MESA RC Scale/Wischers Continued page 145 joint tension truth joint did break time after about five years flying Lake Charles Nats IO0F temperature fastened second time epoxy holds day Castor oil lesser degree lubricants enemy glue joints repairs fiberglass has exposed fuel oil residue must completely removed First scrub methanol dope thinner lacquer thinner ace tone sand away surface bonded sanding drum Dremel tool does best job Fine sanding isnt needed because epoxy fills gaps Finally before mixing epoxy scrub joint area again solvent being careful drag oil prepared area outside oil isnt removed solvent initially sanding ac tion merely imbeds oil workspace solvent cloth should changed often because also becomes oil-contaminated Another glue-joint problem commonly en countered involves unpredictable results tempts join parts made ABS acrylonitrile butadiene styrene either new construction damage repair have tried cementing material ARF model mild success Some joints will fall apart instantly others equivalent weld joint fails probably due contaminants surface whether new old though may appear perfectly clean Preparation cleanliness required especially repairs model fuel has spread over area either direct exposure due wiping model after flight oily cloth Start cleaning joint area solvent such methanol acetone MEK methyl ethyl ketone materials hazardous dont breathe fumes can also ab sorbed through skin MEK especially vicious stuff Use clean wiping cloth facial tissue After few swipes discard cloth fresh certain no residue contaminants remain Roughen surface bonded No 220 aluminum oxide paper wet-sand using No 400 silicon carbide paper water An alternative cleanser kitchen scouring powder water Wash clear water after ward clean area again fresh solvent actual cementing ABS needs overlapped joint using cements intended material have success cements plastic models Glow plugs Several years ago mentioned columns old Champion VG-2 glow plugs served excellently four-stroke engines Unfortunately due attrition sup ply VG-2 now depleted After several seasons usage problem plugs loosening core inside porcelain insulator probably due pounding high cylinder pressure four-stroke new Fox four-stroke shielded plugs have sub stituted performance continues substantially before Champion plugs advantage Scale appearance OS Gemini 120 very closely simulated standard spark plug asked times whether Gemini ignition Except feature can find little difference between Cham pion Fox plugs Bob Dolly Wjscher 5-221 Lapham Peak Rd Delafield WI 53018 RC Giant Scale/de Vries Continied page 55 hes editor invited join NASA Ive intending long time things overlooked press other modeling activities event Stans letter took sent six bucks Bert Dugan secretary treasurer 11090 Phyllis Drive Clio MI 48420 will soon member NASA Any outfit president John Guenther has outstanding met John Scale Internats Paris 84 found him Scale model builders model builder best news Stan Alexanders newsletter confirmation info already passed Wischers FAI has increased weight limits engine sizes little Scale models used international competition fact isnt engine size limit little friends better theyve come up provision al Giant event us build big like contesting world level Specifically new event permits use engines up 61 cu aximum weight 55 lb less fuel maximum surface area event its 7750 sq thats 53 sq ft Thats squares us have ever contemplated Static judging will five meters bit 16 ft Holy Toledo John de Vries 4610 MoffatLn Colorado Springs CO 80915 RC Pylon Racing/Hager Continued page 56 Oliver won race Saturday Phil Bussell coming second Fast time posted Gary Heithold 11406 must say fast time both days Dub Jett posted second fast time second day 11409 Sunday May 31 also 18 entries racing got tougher lots fast airplanes weather almost got us end five rounds Dub Jettwas winner perfect score atie fourth fifth between Dick Ritch newcomer Rick Tocci flyoff really close winner Dick Ritch After flyoff Calcutta held bidding fearsome Dub Jett automati cally race winning Sunday left six others fly off final four spots first race fliers Gary Heithold Dave Layman Bruce Hobbs winner race Dave Layman time 11623 second race Richard Oliver Dick Ritch hit takeoff JP Hanway After long discussion Richard Oliver JP Hanway went final race put final contestants Richard Oliver Dub Jett JP 1-lanway Dave Layman After racing cuts over order finish 1 Dub Jett $288 2 JP Hanway 3 Dave Layman 4 Richard Oliver good time race success lists winners two days First Formula May 30 1 Richard Oliver11951 2 Phil Bussell11978 3 Dub Jett11513 4 Dave Lajman12081 5 JP Hanway12009 6 Bob Greer 12434 7 Hubert Wills12409 8 Dick Ritch 12020 9 Gary Heithold 11406 THE LEADER IN COMPETITION PROPELLERS NEW CYCLE SEiESiGD THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTOGIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MPG OF SELECT HARD MAPLE WOOD WILLNOTFATIGUE LIKE SYNTHETICS FUELPROOFHIGH LUSTER FINISH DIAPITCHPRICE 534149 634149 72833456179 8334568189 845667199 9456677A199 104566/7209 106W8W209 10BEW219 114677778229 IiSW229 11BEW239 1187239 124W279 12SW279 125627w 1356349 1456459 1556659 164N969 16678969 October 1987 149 t5I5tIED & OtWtOPt8 Cli DIA PITCH THP PRICE 12 6677/6 299 13 67/a8379 14 6778 479 1567689 16 678 989 PRO SERIES 3 RC PYLON RACING SERIES 500 DIA PITCH PRICE 75N5/N279 8I 6776 299 SERIES 400C 666777289 9777269 W WIDE BLADE EW EXTRA WIDE N NARROW NEW p TI
