Radio Control Old-Timers Dr DB Mathews SCIENTIFICS VARSITY Ill readily admit overusing Bill Schmidts projects columns keeps doing such weird stuff its just irresistable Case point now hes hauled off built enlarged version model us considered pure turkey darn thing turned out halfbad guess Id better bad-mouth him too much since sort got spiration Scientific Coronet blew up 150%-size resulted really exceptional thermal-flying machine seems 3-enginesize sport models enlarged vast improvement wing loading occurs because rather excessive structures stretched out efficient condi tions Lets face itin original sizes both Varsity Coronet lead sleds great sport hacks certainly no great shakes thermaling Stretch out structure andson gun will work lift best Well maybe Playboy perhaps darn good Construction Varsity fuselage crutch modelers unfamiliar rather common technique Forties era rather stur dy framework built top view fuselage onto series top foriners glued Once desired string ers planking have added unit removed building board bottom formers/stringers/plank ing added method pretty foolproofbut considerable cost weight Theres lot hollow space fuselage built way variation scheme found wartime scale kits Cleveland Comet Joe Ott Some us still have nightmares about trying get pine strips stick paper formers otherwise delightful kits Balsa very short supply during years since Nazi submarines sinking merchant ships bound Ecuador NOTEDIHEORAL 1/2 THIS 1POINT] SECA____ ____ II New York almost opposition What little balsa went life rafts aircraft like DH Mosquito Bomber models years Ive urge go back build another Cleveland P-39 real balsa Has anyone ever done struggled together 1943 arm broken cast guess sort dumbeven kid Believe itor else Im beginning VARSITY WINGSPAN EA 370 50 INS LENGTH33 1/2WEIGHT 22 OZS 0 POWER BROWNIE 29 ENGINE /A KITTED BY SCIENTIFIC MODEL AiRPLANE CO 1941 SEC II2 I1I V L1/52 SHEET COVER HERE-1 TO FIREWALL II I- SCALE IN INCHES 01234568 hIc 1012 Scientific Varsity ads never showed fuselage top Maybe good reason Bill Schmidts 0T enlarged version has twotone color scheme colored slik/clear dope fuchsia wing tail black fuselage Gross Power McCoy 29 igni tionand does thing ever climb Threeview based kit plans RC rudder/elevator surfaces added 52 Model Aviation wonder some sort supernatural phenomenon work sort wild weird things seem hap pen nearly frightening Last time around mentioned oddity donated Kenhi Buzzerd cropping up AMA museum 20 years later about stories borrowed engine Carl Goldbergs Valkyrie eyewitness account Pylon Buster matter Richard Gibbs recently called attention time displayed RC transmitter timer Ace R/C catalog years 440 Weird Continued page 135 Dick Lyons took photos Harry Scatena unique pusher FF over 45 years ago Hed forgotten about until saw new photos Docs December 1985 column Wholl next send some choice old photos EASY-BUILT BY RADIO CONTROLZERO E JAPANESE SPORT SCALETI-I Seen 53 53004 0 kooo ype loing 29 45 engIne good 4 09 0 oob 00 3 4 ohoneel rodlo fIle rodder 011 DeloIled COnoPY 3116 hOt BOICO toil 0110000 r BoIoo Deoko 3/16 FIet Bole Side Formed BOIOO Moon -ripo Foon WIng Cores - ASS____Cowel THE EASY-BUILT ZERO ISA GOOD SUBJECT FOR THE NOVICE FLYER MAKING THE TRANSITION FROM SPORT TRAINERS TO SCALE MODELS BALANCED COMBINATION OF STABILITY AND CONTROL RESPONSE GIVES YOU FEELING OF CONFI DENCE RIGHT FROM THE FIRST FLIGHT THE CONSTRUCTION IS RUGGED AND EASY TO BUILD FEATURING SHEETED FOAM WINGS BALSA SHEETED FUSELAGE BALSA SHEET TAIL AND THERMOFORMED COWL AND CANOPY COMES IN SHORT KIT FORM TO SAVE YOU MONEY KIT INCLUDES FOAM WING CORES COWL CANOPY ENGINE MOUNT LANDING GEAR BLOCKS WITH STRAPS & SCREWS HINGES PLYWOOD FIREWALL PLANS WITH TEMPLATES AND BILL OF MATERIALS NO BALSA INCLUDED PRICE 52695 ORDERING SEND CHECK OR MONEY ORDER FOR $2695 PLUS $450 POSTAGE CANADIANS ADD SOSO TO WING MPG PO B0X33 CRYSTALLAKE1L600I4ILRESIOENTSADDBA%SALES TAO ALL ORDERS MUST BE IN US FUNDS SEND $350 FOR PRODUCT CATALOG DESCRIBING OUR COMPLETE LINE OF FOAM CORE REPLACEMENT WINGS ACCESSORIES KITS TOOLS AND MUCH MORE FHONE 815 4590417 FOR FAST 000 SERVICE April 1986 53 Docs 150%-size Scientific Cornet four-cycles past construction article coming made common metal like copper aluminum shunt heat would direct ly affect shunt resistance thus voltage readingin some cases grossly Hence use vastly stable nichrome metal actual use power lost shunt power avallable motor Looking another way voltage drop shunt voltage denied motor Thus youre likely notice small drop motors rpm shunt installed motor circuit effect will pronounced systems fewer cells Shunt voltage drop smaller percentage voltage bat teries made up large numbers cells readers having DMM highest scale being two amps calibration circuit current would have set value less two amps no particular problem just substitute single 10-ohm 10-watt resistor Radio Shack 271-132 two-ohm set shown circuit current will around 12 amps shunt voltage will around 12 millivolts low value course pushing practical meter limits resulting shunt calibration may prove less accurate obtained higher calibra tion-circuit current meter ac curacy next month Nevertheless principles mentioned analog meter calibration hold case well resulting shunt DMM combination have measurement capability up 20 amps since DMMs typically have low voltage range 200 millivolts Late news SPARKS all-electric club Houston TX has announced Sec ond Spring Fun-Fly April 12-13 event will held Petrosky Ele mentary School its AMA-sanctioned AMA license required enter will offer competitive opportunity low-key basis information con tact Contest Director Eddie Thomas Houston SPARKS 1427 Ashwood Dr Sugar Land TX 77478 713/491-3375 Just mention name youll get extrafine service Thats month Hope helps whove asking meas ure large currents Any comment question may sent author SASE please Bob Kopski 25 West End Dr Lans dale PA 19446 Oh Silent Spring Flights please hurry RC Old-Timers/Mathews Continued page 53 featured series photos December 1985 column has come home roost Dick Lyons now living Camarillo CA formerly Chicago IL sent some photos took model years ago unbeknown Harry Scatena Dick following explanation photos column set bell ringing after much headscratching remembered seen model years ago contest Gary IN fact seemed remember taking some pictures time After much searching through old albums found enclosed photos young modelers attracted very unusual modelas can see crowd photos contest Gary called Little Nationals annual af fair few years before war WW II local department store sponsor attracted very large turn out attended 1939 1940 dont recall year photos taken also have photos Carl Goldberg flying early Interceptor Jim Cahill Dick Obarski among modeling notables meet have mentioned old Gary IN con test previous columns pointing out degree participation non-modeling business fraternal groups sort makes fellow wonder sort sponsorship no longer exists doesnt Also note Harry Scatena some what well-dressed contemporary flying-attire standardsbut about helper suit yet have situation Harry Scatena will see first time photos taken him pusher almost 50 years ago about matter time Dick Lyons another comment letter enjoy col umneven mostly RC Well now guess Ive out Free Flight its pure form long readers have forgotten Im Free Flighter retrieving problems became agony de-feet moved Wichita Greensburg donated over 100 Free Flight trophies local SAM Society Antique Modelers 56 chapter kept National Grand Champion trophies Among Junior firsts Rubber Scale Gas Scale A-l Nordic A-2 Nordic FAL Power B Gas C Gas plus another 40 nd-place lower trophies bird dogs grew up left rely RC solve retrieving spirit still willingbut flesh weak Im Help Help need pictures Free Flight models designed after 1942that nostalgia era detect very con siderable interest among readers Continued page 139 April1986 135 Well time around may take cake folks fascinating old pusher designed built Harry Scatena RC Old-Timers/Mathews Continued page 53 non-SAM-era models Hal deBolt tells will soon start column early RC designs Model Airplane News Id like some material Free Flight same approximate time frame am particularly turned PAA-Load both large small designs wartime goodies such Kid etc some really attractive sport-types such Pacificoaster last column Any photos would greatly appreciated Naturally puts would helpful well Two examples sort thing thinking Veco Sioux Bill Winters Midwest Sniffer enlargements published Flying Models few years back could get excited about sort conceptor impor tant youve tried itwould please drop line Dee B Mathews 8420 Nantucket Wichita KS 67212 RC Giant Scale/Beckman Continued page 55 Conclusion least conclusion Twins multi-engined models dont have considered terrible course theyre going compli cated turns out fail its pretty much same reasons models fall moral story learn failures apply lessons new project Pretty soon failures get few far between Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 RC Pylon Racing/Hager Continued page 56 valve train reaches point valves dont follow bump cam may hit piston 14 x 10 prop its resulting rpm combination will keep well away since engines will run mid 8OOOs ground 10000 air diving three approved engines have redlines well past 12000 rpm Since racing need speed get pitch has increase because four-stroke engines now roughly 10000 rpm saw 15000 two-stroke 60 air Assuming 100 mph before seven-in pitch 15000 rpm now need 10 inches pitch 10000 rpm same speed 7 x 15000 approximately equals 10 x 10000 An added bonus larger prop efficient smaller thrust consistent rpm doesnt fall off turn since four-stroke lugs better meaning doesnt slow down much same ap plies takeoff climbing giving forgiving flight envelope can begin realize what have heard before propeller matching plane engine very important Back power torque Horsepower always combination torque rpm HP UE x RPM x k Torque twisting ability engine crankshaft have lugger always occurs lower rpm horsepow er peak 12 bigger engine has torque 60 half its size 12 generates torque much lower rpm Thats 12 11000 rpm 60 17000 rpm can both rated 16 horsepower just develop different set conditions Two-strokes have become powerhouses because easy increase rpm Look characteristics three engines see HP developed 12 cubic inch four-stroke 60 cubic inch two-stroke 45 cubic inch twostroke ducted fan engine deliver ap proximately 16 HP graph front column RH Torque climbs drops off approximately 2A HP max imum HP keeps climbing after torque drops because rpm still climbing torque drops faster rpm climbs HP starts drop hot engine sharper peaks types engines dif ficult set useful certain props Typically l2s use 13/15-inch prop 60s 11-inch 45s 5/9 inches 45s can actually develop HP cant use because dont have torque turn bigger props need larger prop higher-speed engine wont let engine get its horsepower peak doesnt matter horses liter ature says its rated Look curves 12 closely graph front column BH An engine doesnt develop HP automatically smaller prop just lets get up torque curve closer HP peak raised peak hotter engine may have shifted lower torque-curve anyway Horsepower Hop-up As long compare engines using same prop extra horsepower simple sounds since rpm wont go up itself unless changes made engine hop-up. engine de signed differently torque must creased some other way since rpm must go up takes torque easiest way power let rev. smaller prop less pitchbut allowed fore back torque increase THE LEADER IN COM PETITION NEW i 4 CYCLE THP DESIGN PRICE f 299 379 14479 15689 16989 NEW F 4 j NEW HIGH TECH AIRFOIL SECTION lOTO 20% INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIAPITCHPRICE 534149 634149 72833456179 833/,4568189 845667199 9456677199 104S667209 106W8W209 106EW219 ii46777/,7I,8229 115W229 11SEW239 1167239 124W279 125W279 1256279 1356349 1456459 1556659 164VzN989 16678969 PROPELLERS April1986 139 TAILORED HELICAL PITCH DEVELOPED TO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALL THE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW PITCH THP 86 77 8 877 8 677 8 67 678 PRO SERIES 3 RC PYLON RACING SERIES 500 DIA PITCH PRICE 7SN 5/N279 8I 6/,7/z78 299 SERIES 400C 8 66777 289 9777/289 W WIDE BLADE EW EXTRA WIDE N NARROW
Edition: Model Aviation - 1986/04
Page Numbers: 52, 53, 135, 139
Radio Control Old-Timers Dr DB Mathews SCIENTIFICS VARSITY Ill readily admit overusing Bill Schmidts projects columns keeps doing such weird stuff its just irresistable Case point now hes hauled off built enlarged version model us considered pure turkey darn thing turned out halfbad guess Id better bad-mouth him too much since sort got spiration Scientific Coronet blew up 150%-size resulted really exceptional thermal-flying machine seems 3-enginesize sport models enlarged vast improvement wing loading occurs because rather excessive structures stretched out efficient condi tions Lets face itin original sizes both Varsity Coronet lead sleds great sport hacks certainly no great shakes thermaling Stretch out structure andson gun will work lift best Well maybe Playboy perhaps darn good Construction Varsity fuselage crutch modelers unfamiliar rather common technique Forties era rather stur dy framework built top view fuselage onto series top foriners glued Once desired string ers planking have added unit removed building board bottom formers/stringers/plank ing added method pretty foolproofbut considerable cost weight Theres lot hollow space fuselage built way variation scheme found wartime scale kits Cleveland Comet Joe Ott Some us still have nightmares about trying get pine strips stick paper formers otherwise delightful kits Balsa very short supply during years since Nazi submarines sinking merchant ships bound Ecuador NOTEDIHEORAL 1/2 THIS 1POINT] SECA____ ____ II New York almost opposition What little balsa went life rafts aircraft like DH Mosquito Bomber models years Ive urge go back build another Cleveland P-39 real balsa Has anyone ever done struggled together 1943 arm broken cast guess sort dumbeven kid Believe itor else Im beginning VARSITY WINGSPAN EA 370 50 INS LENGTH33 1/2WEIGHT 22 OZS 0 POWER BROWNIE 29 ENGINE /A KITTED BY SCIENTIFIC MODEL AiRPLANE CO 1941 SEC II2 I1I V L1/52 SHEET COVER HERE-1 TO FIREWALL II I- SCALE IN INCHES 01234568 hIc 1012 Scientific Varsity ads never showed fuselage top Maybe good reason Bill Schmidts 0T enlarged version has twotone color scheme colored slik/clear dope fuchsia wing tail black fuselage Gross Power McCoy 29 igni tionand does thing ever climb Threeview based kit plans RC rudder/elevator surfaces added 52 Model Aviation wonder some sort supernatural phenomenon work sort wild weird things seem hap pen nearly frightening Last time around mentioned oddity donated Kenhi Buzzerd cropping up AMA museum 20 years later about stories borrowed engine Carl Goldbergs Valkyrie eyewitness account Pylon Buster matter Richard Gibbs recently called attention time displayed RC transmitter timer Ace R/C catalog years 440 Weird Continued page 135 Dick Lyons took photos Harry Scatena unique pusher FF over 45 years ago Hed forgotten about until saw new photos Docs December 1985 column Wholl next send some choice old photos EASY-BUILT BY RADIO CONTROLZERO E JAPANESE SPORT SCALETI-I Seen 53 53004 0 kooo ype loing 29 45 engIne good 4 09 0 oob 00 3 4 ohoneel rodlo fIle rodder 011 DeloIled COnoPY 3116 hOt BOICO toil 0110000 r BoIoo Deoko 3/16 FIet Bole Side Formed BOIOO Moon -ripo Foon WIng Cores - ASS____Cowel THE EASY-BUILT ZERO ISA GOOD SUBJECT FOR THE NOVICE FLYER MAKING THE TRANSITION FROM SPORT TRAINERS TO SCALE MODELS BALANCED COMBINATION OF STABILITY AND CONTROL RESPONSE GIVES YOU FEELING OF CONFI DENCE RIGHT FROM THE FIRST FLIGHT THE CONSTRUCTION IS RUGGED AND EASY TO BUILD FEATURING SHEETED FOAM WINGS BALSA SHEETED FUSELAGE BALSA SHEET TAIL AND THERMOFORMED COWL AND CANOPY COMES IN SHORT KIT FORM TO SAVE YOU MONEY KIT INCLUDES FOAM WING CORES COWL CANOPY ENGINE MOUNT LANDING GEAR BLOCKS WITH STRAPS & SCREWS HINGES PLYWOOD FIREWALL PLANS WITH TEMPLATES AND BILL OF MATERIALS NO BALSA INCLUDED PRICE 52695 ORDERING SEND CHECK OR MONEY ORDER FOR $2695 PLUS $450 POSTAGE CANADIANS ADD SOSO TO WING MPG PO B0X33 CRYSTALLAKE1L600I4ILRESIOENTSADDBA%SALES TAO ALL ORDERS MUST BE IN US FUNDS SEND $350 FOR PRODUCT CATALOG DESCRIBING OUR COMPLETE LINE OF FOAM CORE REPLACEMENT WINGS ACCESSORIES KITS TOOLS AND MUCH MORE FHONE 815 4590417 FOR FAST 000 SERVICE April 1986 53 Docs 150%-size Scientific Cornet four-cycles past construction article coming made common metal like copper aluminum shunt heat would direct ly affect shunt resistance thus voltage readingin some cases grossly Hence use vastly stable nichrome metal actual use power lost shunt power avallable motor Looking another way voltage drop shunt voltage denied motor Thus youre likely notice small drop motors rpm shunt installed motor circuit effect will pronounced systems fewer cells Shunt voltage drop smaller percentage voltage bat teries made up large numbers cells readers having DMM highest scale being two amps calibration circuit current would have set value less two amps no particular problem just substitute single 10-ohm 10-watt resistor Radio Shack 271-132 two-ohm set shown circuit current will around 12 amps shunt voltage will around 12 millivolts low value course pushing practical meter limits resulting shunt calibration may prove less accurate obtained higher calibra tion-circuit current meter ac curacy next month Nevertheless principles mentioned analog meter calibration hold case well resulting shunt DMM combination have measurement capability up 20 amps since DMMs typically have low voltage range 200 millivolts Late news SPARKS all-electric club Houston TX has announced Sec ond Spring Fun-Fly April 12-13 event will held Petrosky Ele mentary School its AMA-sanctioned AMA license required enter will offer competitive opportunity low-key basis information con tact Contest Director Eddie Thomas Houston SPARKS 1427 Ashwood Dr Sugar Land TX 77478 713/491-3375 Just mention name youll get extrafine service Thats month Hope helps whove asking meas ure large currents Any comment question may sent author SASE please Bob Kopski 25 West End Dr Lans dale PA 19446 Oh Silent Spring Flights please hurry RC Old-Timers/Mathews Continued page 53 featured series photos December 1985 column has come home roost Dick Lyons now living Camarillo CA formerly Chicago IL sent some photos took model years ago unbeknown Harry Scatena Dick following explanation photos column set bell ringing after much headscratching remembered seen model years ago contest Gary IN fact seemed remember taking some pictures time After much searching through old albums found enclosed photos young modelers attracted very unusual modelas can see crowd photos contest Gary called Little Nationals annual af fair few years before war WW II local department store sponsor attracted very large turn out attended 1939 1940 dont recall year photos taken also have photos Carl Goldberg flying early Interceptor Jim Cahill Dick Obarski among modeling notables meet have mentioned old Gary IN con test previous columns pointing out degree participation non-modeling business fraternal groups sort makes fellow wonder sort sponsorship no longer exists doesnt Also note Harry Scatena some what well-dressed contemporary flying-attire standardsbut about helper suit yet have situation Harry Scatena will see first time photos taken him pusher almost 50 years ago about matter time Dick Lyons another comment letter enjoy col umneven mostly RC Well now guess Ive out Free Flight its pure form long readers have forgotten Im Free Flighter retrieving problems became agony de-feet moved Wichita Greensburg donated over 100 Free Flight trophies local SAM Society Antique Modelers 56 chapter kept National Grand Champion trophies Among Junior firsts Rubber Scale Gas Scale A-l Nordic A-2 Nordic FAL Power B Gas C Gas plus another 40 nd-place lower trophies bird dogs grew up left rely RC solve retrieving spirit still willingbut flesh weak Im Help Help need pictures Free Flight models designed after 1942that nostalgia era detect very con siderable interest among readers Continued page 139 April1986 135 Well time around may take cake folks fascinating old pusher designed built Harry Scatena RC Old-Timers/Mathews Continued page 53 non-SAM-era models Hal deBolt tells will soon start column early RC designs Model Airplane News Id like some material Free Flight same approximate time frame am particularly turned PAA-Load both large small designs wartime goodies such Kid etc some really attractive sport-types such Pacificoaster last column Any photos would greatly appreciated Naturally puts would helpful well Two examples sort thing thinking Veco Sioux Bill Winters Midwest Sniffer enlargements published Flying Models few years back could get excited about sort conceptor impor tant youve tried itwould please drop line Dee B Mathews 8420 Nantucket Wichita KS 67212 RC Giant Scale/Beckman Continued page 55 Conclusion least conclusion Twins multi-engined models dont have considered terrible course theyre going compli cated turns out fail its pretty much same reasons models fall moral story learn failures apply lessons new project Pretty soon failures get few far between Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 RC Pylon Racing/Hager Continued page 56 valve train reaches point valves dont follow bump cam may hit piston 14 x 10 prop its resulting rpm combination will keep well away since engines will run mid 8OOOs ground 10000 air diving three approved engines have redlines well past 12000 rpm Since racing need speed get pitch has increase because four-stroke engines now roughly 10000 rpm saw 15000 two-stroke 60 air Assuming 100 mph before seven-in pitch 15000 rpm now need 10 inches pitch 10000 rpm same speed 7 x 15000 approximately equals 10 x 10000 An added bonus larger prop efficient smaller thrust consistent rpm doesnt fall off turn since four-stroke lugs better meaning doesnt slow down much same ap plies takeoff climbing giving forgiving flight envelope can begin realize what have heard before propeller matching plane engine very important Back power torque Horsepower always combination torque rpm HP UE x RPM x k Torque twisting ability engine crankshaft have lugger always occurs lower rpm horsepow er peak 12 bigger engine has torque 60 half its size 12 generates torque much lower rpm Thats 12 11000 rpm 60 17000 rpm can both rated 16 horsepower just develop different set conditions Two-strokes have become powerhouses because easy increase rpm Look characteristics three engines see HP developed 12 cubic inch four-stroke 60 cubic inch two-stroke 45 cubic inch twostroke ducted fan engine deliver ap proximately 16 HP graph front column RH Torque climbs drops off approximately 2A HP max imum HP keeps climbing after torque drops because rpm still climbing torque drops faster rpm climbs HP starts drop hot engine sharper peaks types engines dif ficult set useful certain props Typically l2s use 13/15-inch prop 60s 11-inch 45s 5/9 inches 45s can actually develop HP cant use because dont have torque turn bigger props need larger prop higher-speed engine wont let engine get its horsepower peak doesnt matter horses liter ature says its rated Look curves 12 closely graph front column BH An engine doesnt develop HP automatically smaller prop just lets get up torque curve closer HP peak raised peak hotter engine may have shifted lower torque-curve anyway Horsepower Hop-up As long compare engines using same prop extra horsepower simple sounds since rpm wont go up itself unless changes made engine hop-up. engine de signed differently torque must creased some other way since rpm must go up takes torque easiest way power let rev. smaller prop less pitchbut allowed fore back torque increase THE LEADER IN COM PETITION NEW i 4 CYCLE THP DESIGN PRICE f 299 379 14479 15689 16989 NEW F 4 j NEW HIGH TECH AIRFOIL SECTION lOTO 20% INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIAPITCHPRICE 534149 634149 72833456179 833/,4568189 845667199 9456677199 104S667209 106W8W209 106EW219 ii46777/,7I,8229 115W229 11SEW239 1167239 124W279 125W279 1256279 1356349 1456459 1556659 164VzN989 16678969 PROPELLERS April1986 139 TAILORED HELICAL PITCH DEVELOPED TO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALL THE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW PITCH THP 86 77 8 877 8 677 8 67 678 PRO SERIES 3 RC PYLON RACING SERIES 500 DIA PITCH PRICE 7SN 5/N279 8I 6/,7/z78 299 SERIES 400C 8 66777 289 9777/289 W WIDE BLADE EW EXTRA WIDE N NARROW
Edition: Model Aviation - 1986/04
Page Numbers: 52, 53, 135, 139
Radio Control Old-Timers Dr DB Mathews SCIENTIFICS VARSITY Ill readily admit overusing Bill Schmidts projects columns keeps doing such weird stuff its just irresistable Case point now hes hauled off built enlarged version model us considered pure turkey darn thing turned out halfbad guess Id better bad-mouth him too much since sort got spiration Scientific Coronet blew up 150%-size resulted really exceptional thermal-flying machine seems 3-enginesize sport models enlarged vast improvement wing loading occurs because rather excessive structures stretched out efficient condi tions Lets face itin original sizes both Varsity Coronet lead sleds great sport hacks certainly no great shakes thermaling Stretch out structure andson gun will work lift best Well maybe Playboy perhaps darn good Construction Varsity fuselage crutch modelers unfamiliar rather common technique Forties era rather stur dy framework built top view fuselage onto series top foriners glued Once desired string ers planking have added unit removed building board bottom formers/stringers/plank ing added method pretty foolproofbut considerable cost weight Theres lot hollow space fuselage built way variation scheme found wartime scale kits Cleveland Comet Joe Ott Some us still have nightmares about trying get pine strips stick paper formers otherwise delightful kits Balsa very short supply during years since Nazi submarines sinking merchant ships bound Ecuador NOTEDIHEORAL 1/2 THIS 1POINT] SECA____ ____ II New York almost opposition What little balsa went life rafts aircraft like DH Mosquito Bomber models years Ive urge go back build another Cleveland P-39 real balsa Has anyone ever done struggled together 1943 arm broken cast guess sort dumbeven kid Believe itor else Im beginning VARSITY WINGSPAN EA 370 50 INS LENGTH33 1/2WEIGHT 22 OZS 0 POWER BROWNIE 29 ENGINE /A KITTED BY SCIENTIFIC MODEL AiRPLANE CO 1941 SEC II2 I1I V L1/52 SHEET COVER HERE-1 TO FIREWALL II I- SCALE IN INCHES 01234568 hIc 1012 Scientific Varsity ads never showed fuselage top Maybe good reason Bill Schmidts 0T enlarged version has twotone color scheme colored slik/clear dope fuchsia wing tail black fuselage Gross Power McCoy 29 igni tionand does thing ever climb Threeview based kit plans RC rudder/elevator surfaces added 52 Model Aviation wonder some sort supernatural phenomenon work sort wild weird things seem hap pen nearly frightening Last time around mentioned oddity donated Kenhi Buzzerd cropping up AMA museum 20 years later about stories borrowed engine Carl Goldbergs Valkyrie eyewitness account Pylon Buster matter Richard Gibbs recently called attention time displayed RC transmitter timer Ace R/C catalog years 440 Weird Continued page 135 Dick Lyons took photos Harry Scatena unique pusher FF over 45 years ago Hed forgotten about until saw new photos Docs December 1985 column Wholl next send some choice old photos EASY-BUILT BY RADIO CONTROLZERO E JAPANESE SPORT SCALETI-I Seen 53 53004 0 kooo ype loing 29 45 engIne good 4 09 0 oob 00 3 4 ohoneel rodlo fIle rodder 011 DeloIled COnoPY 3116 hOt BOICO toil 0110000 r BoIoo Deoko 3/16 FIet Bole Side Formed BOIOO Moon -ripo Foon WIng Cores - ASS____Cowel THE EASY-BUILT ZERO ISA GOOD SUBJECT FOR THE NOVICE FLYER MAKING THE TRANSITION FROM SPORT TRAINERS TO SCALE MODELS BALANCED COMBINATION OF STABILITY AND CONTROL RESPONSE GIVES YOU FEELING OF CONFI DENCE RIGHT FROM THE FIRST FLIGHT THE CONSTRUCTION IS RUGGED AND EASY TO BUILD FEATURING SHEETED FOAM WINGS BALSA SHEETED FUSELAGE BALSA SHEET TAIL AND THERMOFORMED COWL AND CANOPY COMES IN SHORT KIT FORM TO SAVE YOU MONEY KIT INCLUDES FOAM WING CORES COWL CANOPY ENGINE MOUNT LANDING GEAR BLOCKS WITH STRAPS & SCREWS HINGES PLYWOOD FIREWALL PLANS WITH TEMPLATES AND BILL OF MATERIALS NO BALSA INCLUDED PRICE 52695 ORDERING SEND CHECK OR MONEY ORDER FOR $2695 PLUS $450 POSTAGE CANADIANS ADD SOSO TO WING MPG PO B0X33 CRYSTALLAKE1L600I4ILRESIOENTSADDBA%SALES TAO ALL ORDERS MUST BE IN US FUNDS SEND $350 FOR PRODUCT CATALOG DESCRIBING OUR COMPLETE LINE OF FOAM CORE REPLACEMENT WINGS ACCESSORIES KITS TOOLS AND MUCH MORE FHONE 815 4590417 FOR FAST 000 SERVICE April 1986 53 Docs 150%-size Scientific Cornet four-cycles past construction article coming made common metal like copper aluminum shunt heat would direct ly affect shunt resistance thus voltage readingin some cases grossly Hence use vastly stable nichrome metal actual use power lost shunt power avallable motor Looking another way voltage drop shunt voltage denied motor Thus youre likely notice small drop motors rpm shunt installed motor circuit effect will pronounced systems fewer cells Shunt voltage drop smaller percentage voltage bat teries made up large numbers cells readers having DMM highest scale being two amps calibration circuit current would have set value less two amps no particular problem just substitute single 10-ohm 10-watt resistor Radio Shack 271-132 two-ohm set shown circuit current will around 12 amps shunt voltage will around 12 millivolts low value course pushing practical meter limits resulting shunt calibration may prove less accurate obtained higher calibra tion-circuit current meter ac curacy next month Nevertheless principles mentioned analog meter calibration hold case well resulting shunt DMM combination have measurement capability up 20 amps since DMMs typically have low voltage range 200 millivolts Late news SPARKS all-electric club Houston TX has announced Sec ond Spring Fun-Fly April 12-13 event will held Petrosky Ele mentary School its AMA-sanctioned AMA license required enter will offer competitive opportunity low-key basis information con tact Contest Director Eddie Thomas Houston SPARKS 1427 Ashwood Dr Sugar Land TX 77478 713/491-3375 Just mention name youll get extrafine service Thats month Hope helps whove asking meas ure large currents Any comment question may sent author SASE please Bob Kopski 25 West End Dr Lans dale PA 19446 Oh Silent Spring Flights please hurry RC Old-Timers/Mathews Continued page 53 featured series photos December 1985 column has come home roost Dick Lyons now living Camarillo CA formerly Chicago IL sent some photos took model years ago unbeknown Harry Scatena Dick following explanation photos column set bell ringing after much headscratching remembered seen model years ago contest Gary IN fact seemed remember taking some pictures time After much searching through old albums found enclosed photos young modelers attracted very unusual modelas can see crowd photos contest Gary called Little Nationals annual af fair few years before war WW II local department store sponsor attracted very large turn out attended 1939 1940 dont recall year photos taken also have photos Carl Goldberg flying early Interceptor Jim Cahill Dick Obarski among modeling notables meet have mentioned old Gary IN con test previous columns pointing out degree participation non-modeling business fraternal groups sort makes fellow wonder sort sponsorship no longer exists doesnt Also note Harry Scatena some what well-dressed contemporary flying-attire standardsbut about helper suit yet have situation Harry Scatena will see first time photos taken him pusher almost 50 years ago about matter time Dick Lyons another comment letter enjoy col umneven mostly RC Well now guess Ive out Free Flight its pure form long readers have forgotten Im Free Flighter retrieving problems became agony de-feet moved Wichita Greensburg donated over 100 Free Flight trophies local SAM Society Antique Modelers 56 chapter kept National Grand Champion trophies Among Junior firsts Rubber Scale Gas Scale A-l Nordic A-2 Nordic FAL Power B Gas C Gas plus another 40 nd-place lower trophies bird dogs grew up left rely RC solve retrieving spirit still willingbut flesh weak Im Help Help need pictures Free Flight models designed after 1942that nostalgia era detect very con siderable interest among readers Continued page 139 April1986 135 Well time around may take cake folks fascinating old pusher designed built Harry Scatena RC Old-Timers/Mathews Continued page 53 non-SAM-era models Hal deBolt tells will soon start column early RC designs Model Airplane News Id like some material Free Flight same approximate time frame am particularly turned PAA-Load both large small designs wartime goodies such Kid etc some really attractive sport-types such Pacificoaster last column Any photos would greatly appreciated Naturally puts would helpful well Two examples sort thing thinking Veco Sioux Bill Winters Midwest Sniffer enlargements published Flying Models few years back could get excited about sort conceptor impor tant youve tried itwould please drop line Dee B Mathews 8420 Nantucket Wichita KS 67212 RC Giant Scale/Beckman Continued page 55 Conclusion least conclusion Twins multi-engined models dont have considered terrible course theyre going compli cated turns out fail its pretty much same reasons models fall moral story learn failures apply lessons new project Pretty soon failures get few far between Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 RC Pylon Racing/Hager Continued page 56 valve train reaches point valves dont follow bump cam may hit piston 14 x 10 prop its resulting rpm combination will keep well away since engines will run mid 8OOOs ground 10000 air diving three approved engines have redlines well past 12000 rpm Since racing need speed get pitch has increase because four-stroke engines now roughly 10000 rpm saw 15000 two-stroke 60 air Assuming 100 mph before seven-in pitch 15000 rpm now need 10 inches pitch 10000 rpm same speed 7 x 15000 approximately equals 10 x 10000 An added bonus larger prop efficient smaller thrust consistent rpm doesnt fall off turn since four-stroke lugs better meaning doesnt slow down much same ap plies takeoff climbing giving forgiving flight envelope can begin realize what have heard before propeller matching plane engine very important Back power torque Horsepower always combination torque rpm HP UE x RPM x k Torque twisting ability engine crankshaft have lugger always occurs lower rpm horsepow er peak 12 bigger engine has torque 60 half its size 12 generates torque much lower rpm Thats 12 11000 rpm 60 17000 rpm can both rated 16 horsepower just develop different set conditions Two-strokes have become powerhouses because easy increase rpm Look characteristics three engines see HP developed 12 cubic inch four-stroke 60 cubic inch two-stroke 45 cubic inch twostroke ducted fan engine deliver ap proximately 16 HP graph front column RH Torque climbs drops off approximately 2A HP max imum HP keeps climbing after torque drops because rpm still climbing torque drops faster rpm climbs HP starts drop hot engine sharper peaks types engines dif ficult set useful certain props Typically l2s use 13/15-inch prop 60s 11-inch 45s 5/9 inches 45s can actually develop HP cant use because dont have torque turn bigger props need larger prop higher-speed engine wont let engine get its horsepower peak doesnt matter horses liter ature says its rated Look curves 12 closely graph front column BH An engine doesnt develop HP automatically smaller prop just lets get up torque curve closer HP peak raised peak hotter engine may have shifted lower torque-curve anyway Horsepower Hop-up As long compare engines using same prop extra horsepower simple sounds since rpm wont go up itself unless changes made engine hop-up. engine de signed differently torque must creased some other way since rpm must go up takes torque easiest way power let rev. smaller prop less pitchbut allowed fore back torque increase THE LEADER IN COM PETITION NEW i 4 CYCLE THP DESIGN PRICE f 299 379 14479 15689 16989 NEW F 4 j NEW HIGH TECH AIRFOIL SECTION lOTO 20% INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIAPITCHPRICE 534149 634149 72833456179 833/,4568189 845667199 9456677199 104S667209 106W8W209 106EW219 ii46777/,7I,8229 115W229 11SEW239 1167239 124W279 125W279 1256279 1356349 1456459 1556659 164VzN989 16678969 PROPELLERS April1986 139 TAILORED HELICAL PITCH DEVELOPED TO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALL THE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW PITCH THP 86 77 8 877 8 677 8 67 678 PRO SERIES 3 RC PYLON RACING SERIES 500 DIA PITCH PRICE 7SN 5/N279 8I 6/,7/z78 299 SERIES 400C 8 66777 289 9777/289 W WIDE BLADE EW EXTRA WIDE N NARROW
Edition: Model Aviation - 1986/04
Page Numbers: 52, 53, 135, 139
Radio Control Old-Timers Dr DB Mathews SCIENTIFICS VARSITY Ill readily admit overusing Bill Schmidts projects columns keeps doing such weird stuff its just irresistable Case point now hes hauled off built enlarged version model us considered pure turkey darn thing turned out halfbad guess Id better bad-mouth him too much since sort got spiration Scientific Coronet blew up 150%-size resulted really exceptional thermal-flying machine seems 3-enginesize sport models enlarged vast improvement wing loading occurs because rather excessive structures stretched out efficient condi tions Lets face itin original sizes both Varsity Coronet lead sleds great sport hacks certainly no great shakes thermaling Stretch out structure andson gun will work lift best Well maybe Playboy perhaps darn good Construction Varsity fuselage crutch modelers unfamiliar rather common technique Forties era rather stur dy framework built top view fuselage onto series top foriners glued Once desired string ers planking have added unit removed building board bottom formers/stringers/plank ing added method pretty foolproofbut considerable cost weight Theres lot hollow space fuselage built way variation scheme found wartime scale kits Cleveland Comet Joe Ott Some us still have nightmares about trying get pine strips stick paper formers otherwise delightful kits Balsa very short supply during years since Nazi submarines sinking merchant ships bound Ecuador NOTEDIHEORAL 1/2 THIS 1POINT] SECA____ ____ II New York almost opposition What little balsa went life rafts aircraft like DH Mosquito Bomber models years Ive urge go back build another Cleveland P-39 real balsa Has anyone ever done struggled together 1943 arm broken cast guess sort dumbeven kid Believe itor else Im beginning VARSITY WINGSPAN EA 370 50 INS LENGTH33 1/2WEIGHT 22 OZS 0 POWER BROWNIE 29 ENGINE /A KITTED BY SCIENTIFIC MODEL AiRPLANE CO 1941 SEC II2 I1I V L1/52 SHEET COVER HERE-1 TO FIREWALL II I- SCALE IN INCHES 01234568 hIc 1012 Scientific Varsity ads never showed fuselage top Maybe good reason Bill Schmidts 0T enlarged version has twotone color scheme colored slik/clear dope fuchsia wing tail black fuselage Gross Power McCoy 29 igni tionand does thing ever climb Threeview based kit plans RC rudder/elevator surfaces added 52 Model Aviation wonder some sort supernatural phenomenon work sort wild weird things seem hap pen nearly frightening Last time around mentioned oddity donated Kenhi Buzzerd cropping up AMA museum 20 years later about stories borrowed engine Carl Goldbergs Valkyrie eyewitness account Pylon Buster matter Richard Gibbs recently called attention time displayed RC transmitter timer Ace R/C catalog years 440 Weird Continued page 135 Dick Lyons took photos Harry Scatena unique pusher FF over 45 years ago Hed forgotten about until saw new photos Docs December 1985 column Wholl next send some choice old photos EASY-BUILT BY RADIO CONTROLZERO E JAPANESE SPORT SCALETI-I Seen 53 53004 0 kooo ype loing 29 45 engIne good 4 09 0 oob 00 3 4 ohoneel rodlo fIle rodder 011 DeloIled COnoPY 3116 hOt BOICO toil 0110000 r BoIoo Deoko 3/16 FIet Bole Side Formed BOIOO Moon -ripo Foon WIng Cores - ASS____Cowel THE EASY-BUILT ZERO ISA GOOD SUBJECT FOR THE NOVICE FLYER MAKING THE TRANSITION FROM SPORT TRAINERS TO SCALE MODELS BALANCED COMBINATION OF STABILITY AND CONTROL RESPONSE GIVES YOU FEELING OF CONFI DENCE RIGHT FROM THE FIRST FLIGHT THE CONSTRUCTION IS RUGGED AND EASY TO BUILD FEATURING SHEETED FOAM WINGS BALSA SHEETED FUSELAGE BALSA SHEET TAIL AND THERMOFORMED COWL AND CANOPY COMES IN SHORT KIT FORM TO SAVE YOU MONEY KIT INCLUDES FOAM WING CORES COWL CANOPY ENGINE MOUNT LANDING GEAR BLOCKS WITH STRAPS & SCREWS HINGES PLYWOOD FIREWALL PLANS WITH TEMPLATES AND BILL OF MATERIALS NO BALSA INCLUDED PRICE 52695 ORDERING SEND CHECK OR MONEY ORDER FOR $2695 PLUS $450 POSTAGE CANADIANS ADD SOSO TO WING MPG PO B0X33 CRYSTALLAKE1L600I4ILRESIOENTSADDBA%SALES TAO ALL ORDERS MUST BE IN US FUNDS SEND $350 FOR PRODUCT CATALOG DESCRIBING OUR COMPLETE LINE OF FOAM CORE REPLACEMENT WINGS ACCESSORIES KITS TOOLS AND MUCH MORE FHONE 815 4590417 FOR FAST 000 SERVICE April 1986 53 Docs 150%-size Scientific Cornet four-cycles past construction article coming made common metal like copper aluminum shunt heat would direct ly affect shunt resistance thus voltage readingin some cases grossly Hence use vastly stable nichrome metal actual use power lost shunt power avallable motor Looking another way voltage drop shunt voltage denied motor Thus youre likely notice small drop motors rpm shunt installed motor circuit effect will pronounced systems fewer cells Shunt voltage drop smaller percentage voltage bat teries made up large numbers cells readers having DMM highest scale being two amps calibration circuit current would have set value less two amps no particular problem just substitute single 10-ohm 10-watt resistor Radio Shack 271-132 two-ohm set shown circuit current will around 12 amps shunt voltage will around 12 millivolts low value course pushing practical meter limits resulting shunt calibration may prove less accurate obtained higher calibra tion-circuit current meter ac curacy next month Nevertheless principles mentioned analog meter calibration hold case well resulting shunt DMM combination have measurement capability up 20 amps since DMMs typically have low voltage range 200 millivolts Late news SPARKS all-electric club Houston TX has announced Sec ond Spring Fun-Fly April 12-13 event will held Petrosky Ele mentary School its AMA-sanctioned AMA license required enter will offer competitive opportunity low-key basis information con tact Contest Director Eddie Thomas Houston SPARKS 1427 Ashwood Dr Sugar Land TX 77478 713/491-3375 Just mention name youll get extrafine service Thats month Hope helps whove asking meas ure large currents Any comment question may sent author SASE please Bob Kopski 25 West End Dr Lans dale PA 19446 Oh Silent Spring Flights please hurry RC Old-Timers/Mathews Continued page 53 featured series photos December 1985 column has come home roost Dick Lyons now living Camarillo CA formerly Chicago IL sent some photos took model years ago unbeknown Harry Scatena Dick following explanation photos column set bell ringing after much headscratching remembered seen model years ago contest Gary IN fact seemed remember taking some pictures time After much searching through old albums found enclosed photos young modelers attracted very unusual modelas can see crowd photos contest Gary called Little Nationals annual af fair few years before war WW II local department store sponsor attracted very large turn out attended 1939 1940 dont recall year photos taken also have photos Carl Goldberg flying early Interceptor Jim Cahill Dick Obarski among modeling notables meet have mentioned old Gary IN con test previous columns pointing out degree participation non-modeling business fraternal groups sort makes fellow wonder sort sponsorship no longer exists doesnt Also note Harry Scatena some what well-dressed contemporary flying-attire standardsbut about helper suit yet have situation Harry Scatena will see first time photos taken him pusher almost 50 years ago about matter time Dick Lyons another comment letter enjoy col umneven mostly RC Well now guess Ive out Free Flight its pure form long readers have forgotten Im Free Flighter retrieving problems became agony de-feet moved Wichita Greensburg donated over 100 Free Flight trophies local SAM Society Antique Modelers 56 chapter kept National Grand Champion trophies Among Junior firsts Rubber Scale Gas Scale A-l Nordic A-2 Nordic FAL Power B Gas C Gas plus another 40 nd-place lower trophies bird dogs grew up left rely RC solve retrieving spirit still willingbut flesh weak Im Help Help need pictures Free Flight models designed after 1942that nostalgia era detect very con siderable interest among readers Continued page 139 April1986 135 Well time around may take cake folks fascinating old pusher designed built Harry Scatena RC Old-Timers/Mathews Continued page 53 non-SAM-era models Hal deBolt tells will soon start column early RC designs Model Airplane News Id like some material Free Flight same approximate time frame am particularly turned PAA-Load both large small designs wartime goodies such Kid etc some really attractive sport-types such Pacificoaster last column Any photos would greatly appreciated Naturally puts would helpful well Two examples sort thing thinking Veco Sioux Bill Winters Midwest Sniffer enlargements published Flying Models few years back could get excited about sort conceptor impor tant youve tried itwould please drop line Dee B Mathews 8420 Nantucket Wichita KS 67212 RC Giant Scale/Beckman Continued page 55 Conclusion least conclusion Twins multi-engined models dont have considered terrible course theyre going compli cated turns out fail its pretty much same reasons models fall moral story learn failures apply lessons new project Pretty soon failures get few far between Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 RC Pylon Racing/Hager Continued page 56 valve train reaches point valves dont follow bump cam may hit piston 14 x 10 prop its resulting rpm combination will keep well away since engines will run mid 8OOOs ground 10000 air diving three approved engines have redlines well past 12000 rpm Since racing need speed get pitch has increase because four-stroke engines now roughly 10000 rpm saw 15000 two-stroke 60 air Assuming 100 mph before seven-in pitch 15000 rpm now need 10 inches pitch 10000 rpm same speed 7 x 15000 approximately equals 10 x 10000 An added bonus larger prop efficient smaller thrust consistent rpm doesnt fall off turn since four-stroke lugs better meaning doesnt slow down much same ap plies takeoff climbing giving forgiving flight envelope can begin realize what have heard before propeller matching plane engine very important Back power torque Horsepower always combination torque rpm HP UE x RPM x k Torque twisting ability engine crankshaft have lugger always occurs lower rpm horsepow er peak 12 bigger engine has torque 60 half its size 12 generates torque much lower rpm Thats 12 11000 rpm 60 17000 rpm can both rated 16 horsepower just develop different set conditions Two-strokes have become powerhouses because easy increase rpm Look characteristics three engines see HP developed 12 cubic inch four-stroke 60 cubic inch two-stroke 45 cubic inch twostroke ducted fan engine deliver ap proximately 16 HP graph front column RH Torque climbs drops off approximately 2A HP max imum HP keeps climbing after torque drops because rpm still climbing torque drops faster rpm climbs HP starts drop hot engine sharper peaks types engines dif ficult set useful certain props Typically l2s use 13/15-inch prop 60s 11-inch 45s 5/9 inches 45s can actually develop HP cant use because dont have torque turn bigger props need larger prop higher-speed engine wont let engine get its horsepower peak doesnt matter horses liter ature says its rated Look curves 12 closely graph front column BH An engine doesnt develop HP automatically smaller prop just lets get up torque curve closer HP peak raised peak hotter engine may have shifted lower torque-curve anyway Horsepower Hop-up As long compare engines using same prop extra horsepower simple sounds since rpm wont go up itself unless changes made engine hop-up. engine de signed differently torque must creased some other way since rpm must go up takes torque easiest way power let rev. smaller prop less pitchbut allowed fore back torque increase THE LEADER IN COM PETITION NEW i 4 CYCLE THP DESIGN PRICE f 299 379 14479 15689 16989 NEW F 4 j NEW HIGH TECH AIRFOIL SECTION lOTO 20% INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIAPITCHPRICE 534149 634149 72833456179 833/,4568189 845667199 9456677199 104S667209 106W8W209 106EW219 ii46777/,7I,8229 115W229 11SEW239 1167239 124W279 125W279 1256279 1356349 1456459 1556659 164VzN989 16678969 PROPELLERS April1986 139 TAILORED HELICAL PITCH DEVELOPED TO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALL THE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW PITCH THP 86 77 8 877 8 677 8 67 678 PRO SERIES 3 RC PYLON RACING SERIES 500 DIA PITCH PRICE 7SN 5/N279 8I 6/,7/z78 299 SERIES 400C 8 66777 289 9777/289 W WIDE BLADE EW EXTRA WIDE N NARROW