Beckman Kirby Crawford Ii angers foi Quadra engine greater use other Giant Scale engine type has around longer Actually have three variations Quadra through years authors provide much data Part 2 SCRATCH majority Giant Scale models youll uncover Quadra under cowl quite few big bangers available now Quadra first appear real quantity Literally thousands now use Most Giant Scale kits market designed Quadra since about thing around kits developed two three years ago blocky looking Canadian chainsaw engine has con tinues have tremendous influence whole Giant Scale field Part series included version Quadra basically three slightly differ ent versions market original model version factory balanced flywheel latest model minor external changes some significant internal changes addi tion three might have Brisighella balanced flywheel installed making six varia tionsand confusion reigns supreme IZhZI7~TZD TZ GTZTZG ZZ Engine20-820-820-1020-1020-1020-1222-622-622-822-822-1022-1016-6 Idle RPM200018001800170018001500170017001500160013001400 Top RPM550053005000500050004000500056004600500039004000 oThrustinlb17171551651651216517516171314 U Idle RPM2000 1800 1800 1800 1800 1500 1700 1700 1500 1600 1300 14002000 U Top RPM5300 5300 5000 5000 5000 4300 5100 5300 4800 5000 4100 45008000 oThrustinlb175 175 165 165 1714175 175 1817151616 U Idle RPM2000 2000 1900 1900 1900 1800 2000 2000 1900 2000 1800 18002200 U C Top RPM5200 5400 5000 5100 5100 4200 5300 5800 5000 5000 4000 41008200 OThrustinlb175 175 16165 175 125 17185 17175 151517 y modelB rmediateC st model 30 Model Aviation Left latest model Uuadra left earliest right Note change top cylinder cleaner shiny cast ing new model Right useful accessories available Shown new model CB Associates mount six-bolt prop adapter Original sand-cast mount weighs 6% oz latest die-cast version weighs 4% oz aluminum hub weighs same steel original Supplier Trail Manufacturing PO Box 549 Huron Park Ont Can Original use Chainsaw Price $13995 Availability Dealers & mail order Mfg Trail Manufacturing Weight 3 lb 13 oz no mount TEST DATA SUMMARY Max thrust 195 lb @ 6800 rpm Zinger 20-6 Kolbo 20-5 161 fuel mix @ 89 oz/min fuel consumption Accessories supplied Engine mount No Prop hub Center bolt 5/16-24 Muffler Chainsaw-type Other None Additional items required excluding prop fuel tank Engine mount right-angle throttle linkage Recommended propeller 16-6 205 Recommended fuel mix 161 Carburetor Make type Waibro diaphram fuel pump Controls available Throttle Adjustments avail Idle stop screw high low mixture Ignition Type Magneto mechanical points Spark plug Champion RCJ8Recommended gap 0025 Magneto gap 010 inPoint gap 0015 Kill disable system None suppliedmag ground easily added Internal details Induction Direct piston porting Cylinder Cast machined aluminum Piston rings Cast machined aluminumone ring Crankshaft One piece cast steel Bearings Caged rollerfront rear Conrod Stamped steel plate Bearings Roller bearing crankpin Dimensions Orientation dimensions looking forward along crankshaft upright engine Prop refers propeller back side 1 Firewall prop mount supplied 6-1/16 rear shaft prop 2 Prop rearmost point excluding rear shaft 5-3/4 plug 3 Prop forwardmost point 1 magneto 4 Maximum extension thrust line 5-3/16 plug @ 5/2 behind prop 5 Vertical dimensions thrust line a Up 5-3/16 plug @5 behind prop b Down 1-3/4 flywheel @1% behind prop 6 Horizontal extension thrust line 3-11/16 carb @2 behind prop 7 Propeller hub diameter 0975 in Bolt hole diameter NA 8 Propeller washer 1 dia aluminum -in thick 9 Mounting bolt pattern Depends mount used Subjective items following beyond ability measure di rectly off ered opinions what worth 1 Overall appearance Typical chainsaw engine compact 2 Amount quality instructions Three pages little specif ic technical information Instructions being revised thistime 3 Ease starting a Cold Good 15 20 flips b Hot Excellent 1 5 flips 4 Ease mounting control hook-up Recommend use com mercially-available mount vertical throttle requires bellcrank 5 Ease carburetor adjustments Only idle screw accesible engine running 6 Vibration levels Noticeable excessive 7 Cowlability Rear exhaust side-mounted carb can cause prob lems smaller models 8 Crankshaft bearing slop Obviousmost pronounced engines tested part Big Bangers will try clear up some confusion Before getting Quadra however want make few comments apply test series general 1 Keep mind static thrust doesnt tell whole story about engine/propeller/aircraft combination Before through plan report in-flight experience engines props can 2 engines run mufflers though know little back pressure usually helps Since didnt have mufflers al/the engines felt would better use 3 nature test equipment thrust figures precise rpm figures lucky read rpm can read thrust 025 lb Dont get upset see things results like two different thrust readings same prop apparently same rpm Now lets talk Quadras Quadra manufactured Canada Trail Manufacturing Ltd Trail produces several products powered small gasoline engines Quadra based smaller chainsaw engines has around some time chainsaw certain amount engine vibration tolerable can useful miniature aircraft Early big bird buffs welcomed power available Quadra soon found along power came vibration could did shake planes apart Shock absorbing motor mounts tighter rugged construction techniques quickly developed cope situation modeler Dario Brisighella went step farther attacked source problem no way get rid engine vibration especially single-cylinder engine However since some vibration due ZDT ZDTZ T Z K TZDProp 16-818-618-618618-818-818-818-10 18-10 20-520620-620-8Engine 2000200018002000200019001900180017001800200020002000Idle RPM 7600680076006900670068007000600060006700600066006000Top RPM 15515518175161751716161918185175Thrustinlb 2000200018002000190020001900180017001800200020002000Idle RPM0 780068007800710069006900__7000600061006700600069006000Top RPM 175 165 19 185 17 19 19 17 165 195 175 195 175 Thrustinlb 2200220023002300220022002100200021002200200022002200Idle RPM 0 7900 6800 7800 7000 6900 6900 7000 6000 6100 6800 6000 6800 6000Top RPM 175 16 18 175 17 175 18 17 17 195 18 195 175 Thrust lb D thrust G h K o T Flite Z er July 1981 31 QUADRA ENGINE DATA Latest Version Displacement 2 Cu dynamic imbalances crankshaft/con rod piston system Dario reasoned properly unbalanced flywheel could help balance total ystem idea successful enough Dario now offers modification commercial basis Please note overbalancing simple process requires equipment knowhow available us addition Brisighella balanced flywheel usable Quadra engine other engine likely increase vibration decrease Darios modification has become popular Trail looked year ago introduced Quadra model factory balanced flywheel should confused Danas flywheel Possibly legal economic reasons Trail cannot exactly what Dana does vibration under reasonably good control Quadra influential explosive growth Giant Scale activity growth came new engines compete marketplace product has con tinually improved latest version Quadra result Trail Manufacturings desire maintain position Giant Scale activities following portion letter Bob Cooper af Trail describing changes .. External changesi Elimination peak cooling fins above spark plug boss 2 Elimi nation cooling fin flashing along mold separation line 3 mounting screw lands have gusset supports increased strength 4 Exhaust port carburetor mounting faces have increased size add strength . Internalchanges 1 Bypass ports have increased size deflection angles changed 2 New connecting rod being used 3 New crankshaft being incorporated addition letter Bob sent two engines use tests early model original flywheel other latest version first Quadra turned Out ta intermediate version now have complete set tell apart obvious external difference between latest Quadra earlier models lack vertical cooling fins top ofthe head reliable identifier however since modelers have removed fins themselves new old engine side side cleaner fins beefed up screw lands obvious addition new castings have slightly shiny finish old ones have matte sandblasted appearance internal differences difficult detect eye Thats surprising since minute differences things like porting angles can significant Mare sophisticated equipment have available would required get meaningful data Bob Cooper concerned about disas sembling engines points out instructions warn against doing agree no reason average modeler get inside engine Bobs concern linked fact crankshaft bearings clamped place upper lower crankcase castings bearings proper ly located during reassembly improper crank shaft end-play results can lead lowered performance reassemble engines have recommended three- five-thou sandths inch end-play crankshaft Crankshaft end-play should confused what refer crankshaft bearing slop slop mean amount shaft can moved right angles thrust line End-play movement along thrust line engine needs small finite amount slop particularly important engines large flywheels because less slop smaller magneto air-gap can means spark will hotter engine will start run better test data presented recorded same day Engine B same engine included first report re-ran tests along C conditions would similar possible addition some rpm figures first Quadra B runs now suspect unavoidable difference between B other two total running time opinion difference break-in time significant Engine B seemed have slight edge performance C coming strong its running time increased Comparing C engine C newest version showed slightly better performance importantly improving increased running time After completion initial test series engine run Dario Brisighellas overbalanced flywheels found no signifi cant difference recordable performance have some subjective impressions no real difference top rpm thrust idling improved No obvious differ ence virbration could identified feel going apparent engine airframe reserving judg ment point temporarily both building Quadra-powered planes modeler weve talked has used Danas flywheel reports decreased vibration save space avoid boredom including data sheet newest engine since three versions almost identi cal few differences listed below 1 engine B maximum extension thrust line top fin 5 3s behind prop 2 engine maximum thrust 19 lb Kolbo 20-5 3 engines B fuel consumption ounce per minute authors primary result portion test series greatly increased Continued page 110 32 Model Aviation Three different flywheels Quadra original left factory-balanced centeridentifiable two nail heads oppositethe magnets Brisighella flywheel right Back sides latest stock Quadra flywheel left Brisighella overbalanced flywheel right Overbalancing requiresequipment available modelers photos Bob Beckman ndiub tile various manufacturers Big Banger project has commercial props available test runs Included Dynathrust Grish Kolbo Top Flite Zinger FEATURES INCLUDE Space battery & meter panel Transmitter compartment Room gallon fuel MASIER AIRSC1U Ii FLIGHTBOX KIT Master Airscrew Flight Box has features larger boxes compact handy arrangement parts cut imported mahogany plywood will take stain varnish paint finishes overall size 19Wx9Y2x 12 high $3at dealer 495 postpaid California add 6% Sales Tax Propeller storage Gravity closed small parts storage 7/8 aluminum handle Complete instructions & fasteners WINDSOR PROPELLER CO PO Box 112Windsor CA 95492 joe6e1sewA.dzeexf&zt WRITE FOR COMPLETE PRODUCT LISTING MANUFACTURERS AND DEALERS INQUIRIES INVITED SPECIAL SIZES AVAILABLE ADD $300 FOR POSTAGE AND HANDLING NMG MODELS INC P 0 BOX 396 BY MD 20657 301 326-2554 surface before second applied Koverall will seal fill two three Coats K&B nitrate dope combination accepts polyure thane paints no blistering peeling wing tail surfaces can also covered Koverall highly durable structurally strong inexpensive finish However wings tail sufficently rigid safe use sucfi films MonoKote Im sure about lower temperature films however Flying thorough check-out systems components should conducted leisurely pace home Once everything working per fectly haul yourself Rearwin Junior nearest flying field prepared have ball Ground handling squirrely BALSA SHEETS 4x48x/ie49 4x48x3A3252 4x48x%62 4x48x3/1674 4x48x90 4x48x/2108 6x48x/it74 6x48x3A3278 6x48x/893 6x48x135 6X48x/2162 PLYWOOD 6x48xA32125 6x48x/ie136 6x48x3A32175 6x48x/a185 6x48x3/16240 6x48x280 BALSA BLOCKS 1x2x2462 1x3x2486 1x4x24126 2x2x2486 2x3x24126 3x3x24240 tail-dragger Just advance throttle slowly until rudder gets bite air As throttle advanced will break ground little need up elevator Turns rudder-only gentle slightly reverse rudder control level wings ailerons model requires some opposite rud der counteract dihedral particularly left turn Landings slow gentle needs line up runway about 150 ft out 30 ft high retard throttle let float glide such may have resort down elevator get wheels Onto grass Junior has natural tendency land three-point attitude sufficient speed burned off airplane can flown anyone has 110 Model Aviation bit stick time Old-Timer Stalls mushy havent able spin has no tendency snap low speed nor pitch high speed Rearwin Junior flies like heavy Old-Timer RC assistnot surprising development thats really what Build yourself construction simple strong flies beautifully Most amazingly realistic air fun-to-work ratio design leans strongly fun side Enjoy References Aviation History Greater Kansas City Cub Flyers Publications Library Congress Catalog No 74-119630 Lightplanes Since 1909 John Underwood George Collinge Heritage Press Library Congress Catalog No 69-17709 Air Progress January 1968 Wonder ful Rearwins Some Giant Birds John W Underwood Vintage Veteran Aircraft Guide John Underwood Collinwood Press Library Congress Catalog No 68-28978 Collect-Air Photos PO Box 14234 Milwau kee WI 53214 set No 136 Big Bangers/Beckman Continued page 32 respect Quadra its capabilities three engines easy starting Thrust outputs some cases surprisingly high improving running time Vibration levels excessive lower some other chainsaw-derived engines added considerations availability price its hard beat wish thank following support portion project Dario Brisighella 1032 East Manitowoc Ave Oak Creek WI 53154 CB Associates Inc 21658 Cloud Way Hay ward CA 94545 Dynathrust Props Inc 2541 NE 11th Court Pompano Beach FL 33062 Grish Bros St John IN 46373 JZ ProductsZinger 25029S Vermont Ave Harbor City CA 90710 Top Flite Models Inc 1901 Narragansett Ave Chicago IL 60639 Trail Manufacturing Ltd Huron Park Ont NOM lYO Canada H ELI- FLI/Burdin Continued page 37 doing maneuver correctly wdrd flight will come Level V get practice basics finished calm weather practice go back repeat Level IV ma neuvers light breeze JS Dont think trying circle-arounds wind until previous work has practiced windy conditions wind direction will constant its effect Helicopter will continously change fly around circle Approach maneuver same caution did first circle-around practice wind emphasized level unless learn youll always waiting calm day evening youll get little flying JS finally comfortable wind various orientations its time remove training gear return original factory-supplied equipment will some obvious changes machines performance THE CHEROKEE THE REAPER BalsaBalsa Fuselage Fast Assembly S/ow FlyingSheeted Foam Core Wing 3-4 Channels4-6 Channels 19-25 Engine40-60 Engine $6995
Edition: Model Aviation - 1981/07
Page Numbers: 30, 31, 32, 110
Beckman Kirby Crawford Ii angers foi Quadra engine greater use other Giant Scale engine type has around longer Actually have three variations Quadra through years authors provide much data Part 2 SCRATCH majority Giant Scale models youll uncover Quadra under cowl quite few big bangers available now Quadra first appear real quantity Literally thousands now use Most Giant Scale kits market designed Quadra since about thing around kits developed two three years ago blocky looking Canadian chainsaw engine has con tinues have tremendous influence whole Giant Scale field Part series included version Quadra basically three slightly differ ent versions market original model version factory balanced flywheel latest model minor external changes some significant internal changes addi tion three might have Brisighella balanced flywheel installed making six varia tionsand confusion reigns supreme IZhZI7~TZD TZ GTZTZG ZZ Engine20-820-820-1020-1020-1020-1222-622-622-822-822-1022-1016-6 Idle RPM200018001800170018001500170017001500160013001400 Top RPM550053005000500050004000500056004600500039004000 oThrustinlb17171551651651216517516171314 U Idle RPM2000 1800 1800 1800 1800 1500 1700 1700 1500 1600 1300 14002000 U Top RPM5300 5300 5000 5000 5000 4300 5100 5300 4800 5000 4100 45008000 oThrustinlb175 175 165 165 1714175 175 1817151616 U Idle RPM2000 2000 1900 1900 1900 1800 2000 2000 1900 2000 1800 18002200 U C Top RPM5200 5400 5000 5100 5100 4200 5300 5800 5000 5000 4000 41008200 OThrustinlb175 175 16165 175 125 17185 17175 151517 y modelB rmediateC st model 30 Model Aviation Left latest model Uuadra left earliest right Note change top cylinder cleaner shiny cast ing new model Right useful accessories available Shown new model CB Associates mount six-bolt prop adapter Original sand-cast mount weighs 6% oz latest die-cast version weighs 4% oz aluminum hub weighs same steel original Supplier Trail Manufacturing PO Box 549 Huron Park Ont Can Original use Chainsaw Price $13995 Availability Dealers & mail order Mfg Trail Manufacturing Weight 3 lb 13 oz no mount TEST DATA SUMMARY Max thrust 195 lb @ 6800 rpm Zinger 20-6 Kolbo 20-5 161 fuel mix @ 89 oz/min fuel consumption Accessories supplied Engine mount No Prop hub Center bolt 5/16-24 Muffler Chainsaw-type Other None Additional items required excluding prop fuel tank Engine mount right-angle throttle linkage Recommended propeller 16-6 205 Recommended fuel mix 161 Carburetor Make type Waibro diaphram fuel pump Controls available Throttle Adjustments avail Idle stop screw high low mixture Ignition Type Magneto mechanical points Spark plug Champion RCJ8Recommended gap 0025 Magneto gap 010 inPoint gap 0015 Kill disable system None suppliedmag ground easily added Internal details Induction Direct piston porting Cylinder Cast machined aluminum Piston rings Cast machined aluminumone ring Crankshaft One piece cast steel Bearings Caged rollerfront rear Conrod Stamped steel plate Bearings Roller bearing crankpin Dimensions Orientation dimensions looking forward along crankshaft upright engine Prop refers propeller back side 1 Firewall prop mount supplied 6-1/16 rear shaft prop 2 Prop rearmost point excluding rear shaft 5-3/4 plug 3 Prop forwardmost point 1 magneto 4 Maximum extension thrust line 5-3/16 plug @ 5/2 behind prop 5 Vertical dimensions thrust line a Up 5-3/16 plug @5 behind prop b Down 1-3/4 flywheel @1% behind prop 6 Horizontal extension thrust line 3-11/16 carb @2 behind prop 7 Propeller hub diameter 0975 in Bolt hole diameter NA 8 Propeller washer 1 dia aluminum -in thick 9 Mounting bolt pattern Depends mount used Subjective items following beyond ability measure di rectly off ered opinions what worth 1 Overall appearance Typical chainsaw engine compact 2 Amount quality instructions Three pages little specif ic technical information Instructions being revised thistime 3 Ease starting a Cold Good 15 20 flips b Hot Excellent 1 5 flips 4 Ease mounting control hook-up Recommend use com mercially-available mount vertical throttle requires bellcrank 5 Ease carburetor adjustments Only idle screw accesible engine running 6 Vibration levels Noticeable excessive 7 Cowlability Rear exhaust side-mounted carb can cause prob lems smaller models 8 Crankshaft bearing slop Obviousmost pronounced engines tested part Big Bangers will try clear up some confusion Before getting Quadra however want make few comments apply test series general 1 Keep mind static thrust doesnt tell whole story about engine/propeller/aircraft combination Before through plan report in-flight experience engines props can 2 engines run mufflers though know little back pressure usually helps Since didnt have mufflers al/the engines felt would better use 3 nature test equipment thrust figures precise rpm figures lucky read rpm can read thrust 025 lb Dont get upset see things results like two different thrust readings same prop apparently same rpm Now lets talk Quadras Quadra manufactured Canada Trail Manufacturing Ltd Trail produces several products powered small gasoline engines Quadra based smaller chainsaw engines has around some time chainsaw certain amount engine vibration tolerable can useful miniature aircraft Early big bird buffs welcomed power available Quadra soon found along power came vibration could did shake planes apart Shock absorbing motor mounts tighter rugged construction techniques quickly developed cope situation modeler Dario Brisighella went step farther attacked source problem no way get rid engine vibration especially single-cylinder engine However since some vibration due ZDT ZDTZ T Z K TZDProp 16-818-618-618618-818-818-818-10 18-10 20-520620-620-8Engine 2000200018002000200019001900180017001800200020002000Idle RPM 7600680076006900670068007000600060006700600066006000Top RPM 15515518175161751716161918185175Thrustinlb 2000200018002000190020001900180017001800200020002000Idle RPM0 780068007800710069006900__7000600061006700600069006000Top RPM 175 165 19 185 17 19 19 17 165 195 175 195 175 Thrustinlb 2200220023002300220022002100200021002200200022002200Idle RPM 0 7900 6800 7800 7000 6900 6900 7000 6000 6100 6800 6000 6800 6000Top RPM 175 16 18 175 17 175 18 17 17 195 18 195 175 Thrust lb D thrust G h K o T Flite Z er July 1981 31 QUADRA ENGINE DATA Latest Version Displacement 2 Cu dynamic imbalances crankshaft/con rod piston system Dario reasoned properly unbalanced flywheel could help balance total ystem idea successful enough Dario now offers modification commercial basis Please note overbalancing simple process requires equipment knowhow available us addition Brisighella balanced flywheel usable Quadra engine other engine likely increase vibration decrease Darios modification has become popular Trail looked year ago introduced Quadra model factory balanced flywheel should confused Danas flywheel Possibly legal economic reasons Trail cannot exactly what Dana does vibration under reasonably good control Quadra influential explosive growth Giant Scale activity growth came new engines compete marketplace product has con tinually improved latest version Quadra result Trail Manufacturings desire maintain position Giant Scale activities following portion letter Bob Cooper af Trail describing changes .. External changesi Elimination peak cooling fins above spark plug boss 2 Elimi nation cooling fin flashing along mold separation line 3 mounting screw lands have gusset supports increased strength 4 Exhaust port carburetor mounting faces have increased size add strength . Internalchanges 1 Bypass ports have increased size deflection angles changed 2 New connecting rod being used 3 New crankshaft being incorporated addition letter Bob sent two engines use tests early model original flywheel other latest version first Quadra turned Out ta intermediate version now have complete set tell apart obvious external difference between latest Quadra earlier models lack vertical cooling fins top ofthe head reliable identifier however since modelers have removed fins themselves new old engine side side cleaner fins beefed up screw lands obvious addition new castings have slightly shiny finish old ones have matte sandblasted appearance internal differences difficult detect eye Thats surprising since minute differences things like porting angles can significant Mare sophisticated equipment have available would required get meaningful data Bob Cooper concerned about disas sembling engines points out instructions warn against doing agree no reason average modeler get inside engine Bobs concern linked fact crankshaft bearings clamped place upper lower crankcase castings bearings proper ly located during reassembly improper crank shaft end-play results can lead lowered performance reassemble engines have recommended three- five-thou sandths inch end-play crankshaft Crankshaft end-play should confused what refer crankshaft bearing slop slop mean amount shaft can moved right angles thrust line End-play movement along thrust line engine needs small finite amount slop particularly important engines large flywheels because less slop smaller magneto air-gap can means spark will hotter engine will start run better test data presented recorded same day Engine B same engine included first report re-ran tests along C conditions would similar possible addition some rpm figures first Quadra B runs now suspect unavoidable difference between B other two total running time opinion difference break-in time significant Engine B seemed have slight edge performance C coming strong its running time increased Comparing C engine C newest version showed slightly better performance importantly improving increased running time After completion initial test series engine run Dario Brisighellas overbalanced flywheels found no signifi cant difference recordable performance have some subjective impressions no real difference top rpm thrust idling improved No obvious differ ence virbration could identified feel going apparent engine airframe reserving judg ment point temporarily both building Quadra-powered planes modeler weve talked has used Danas flywheel reports decreased vibration save space avoid boredom including data sheet newest engine since three versions almost identi cal few differences listed below 1 engine B maximum extension thrust line top fin 5 3s behind prop 2 engine maximum thrust 19 lb Kolbo 20-5 3 engines B fuel consumption ounce per minute authors primary result portion test series greatly increased Continued page 110 32 Model Aviation Three different flywheels Quadra original left factory-balanced centeridentifiable two nail heads oppositethe magnets Brisighella flywheel right Back sides latest stock Quadra flywheel left Brisighella overbalanced flywheel right Overbalancing requiresequipment available modelers photos Bob Beckman ndiub tile various manufacturers Big Banger project has commercial props available test runs Included Dynathrust Grish Kolbo Top Flite Zinger FEATURES INCLUDE Space battery & meter panel Transmitter compartment Room gallon fuel MASIER AIRSC1U Ii FLIGHTBOX KIT Master Airscrew Flight Box has features larger boxes compact handy arrangement parts cut imported mahogany plywood will take stain varnish paint finishes overall size 19Wx9Y2x 12 high $3at dealer 495 postpaid California add 6% Sales Tax Propeller storage Gravity closed small parts storage 7/8 aluminum handle Complete instructions & fasteners WINDSOR PROPELLER CO PO Box 112Windsor CA 95492 joe6e1sewA.dzeexf&zt WRITE FOR COMPLETE PRODUCT LISTING MANUFACTURERS AND DEALERS INQUIRIES INVITED SPECIAL SIZES AVAILABLE ADD $300 FOR POSTAGE AND HANDLING NMG MODELS INC P 0 BOX 396 BY MD 20657 301 326-2554 surface before second applied Koverall will seal fill two three Coats K&B nitrate dope combination accepts polyure thane paints no blistering peeling wing tail surfaces can also covered Koverall highly durable structurally strong inexpensive finish However wings tail sufficently rigid safe use sucfi films MonoKote Im sure about lower temperature films however Flying thorough check-out systems components should conducted leisurely pace home Once everything working per fectly haul yourself Rearwin Junior nearest flying field prepared have ball Ground handling squirrely BALSA SHEETS 4x48x/ie49 4x48x3A3252 4x48x%62 4x48x3/1674 4x48x90 4x48x/2108 6x48x/it74 6x48x3A3278 6x48x/893 6x48x135 6X48x/2162 PLYWOOD 6x48xA32125 6x48x/ie136 6x48x3A32175 6x48x/a185 6x48x3/16240 6x48x280 BALSA BLOCKS 1x2x2462 1x3x2486 1x4x24126 2x2x2486 2x3x24126 3x3x24240 tail-dragger Just advance throttle slowly until rudder gets bite air As throttle advanced will break ground little need up elevator Turns rudder-only gentle slightly reverse rudder control level wings ailerons model requires some opposite rud der counteract dihedral particularly left turn Landings slow gentle needs line up runway about 150 ft out 30 ft high retard throttle let float glide such may have resort down elevator get wheels Onto grass Junior has natural tendency land three-point attitude sufficient speed burned off airplane can flown anyone has 110 Model Aviation bit stick time Old-Timer Stalls mushy havent able spin has no tendency snap low speed nor pitch high speed Rearwin Junior flies like heavy Old-Timer RC assistnot surprising development thats really what Build yourself construction simple strong flies beautifully Most amazingly realistic air fun-to-work ratio design leans strongly fun side Enjoy References Aviation History Greater Kansas City Cub Flyers Publications Library Congress Catalog No 74-119630 Lightplanes Since 1909 John Underwood George Collinge Heritage Press Library Congress Catalog No 69-17709 Air Progress January 1968 Wonder ful Rearwins Some Giant Birds John W Underwood Vintage Veteran Aircraft Guide John Underwood Collinwood Press Library Congress Catalog No 68-28978 Collect-Air Photos PO Box 14234 Milwau kee WI 53214 set No 136 Big Bangers/Beckman Continued page 32 respect Quadra its capabilities three engines easy starting Thrust outputs some cases surprisingly high improving running time Vibration levels excessive lower some other chainsaw-derived engines added considerations availability price its hard beat wish thank following support portion project Dario Brisighella 1032 East Manitowoc Ave Oak Creek WI 53154 CB Associates Inc 21658 Cloud Way Hay ward CA 94545 Dynathrust Props Inc 2541 NE 11th Court Pompano Beach FL 33062 Grish Bros St John IN 46373 JZ ProductsZinger 25029S Vermont Ave Harbor City CA 90710 Top Flite Models Inc 1901 Narragansett Ave Chicago IL 60639 Trail Manufacturing Ltd Huron Park Ont NOM lYO Canada H ELI- FLI/Burdin Continued page 37 doing maneuver correctly wdrd flight will come Level V get practice basics finished calm weather practice go back repeat Level IV ma neuvers light breeze JS Dont think trying circle-arounds wind until previous work has practiced windy conditions wind direction will constant its effect Helicopter will continously change fly around circle Approach maneuver same caution did first circle-around practice wind emphasized level unless learn youll always waiting calm day evening youll get little flying JS finally comfortable wind various orientations its time remove training gear return original factory-supplied equipment will some obvious changes machines performance THE CHEROKEE THE REAPER BalsaBalsa Fuselage Fast Assembly S/ow FlyingSheeted Foam Core Wing 3-4 Channels4-6 Channels 19-25 Engine40-60 Engine $6995
Edition: Model Aviation - 1981/07
Page Numbers: 30, 31, 32, 110
Beckman Kirby Crawford Ii angers foi Quadra engine greater use other Giant Scale engine type has around longer Actually have three variations Quadra through years authors provide much data Part 2 SCRATCH majority Giant Scale models youll uncover Quadra under cowl quite few big bangers available now Quadra first appear real quantity Literally thousands now use Most Giant Scale kits market designed Quadra since about thing around kits developed two three years ago blocky looking Canadian chainsaw engine has con tinues have tremendous influence whole Giant Scale field Part series included version Quadra basically three slightly differ ent versions market original model version factory balanced flywheel latest model minor external changes some significant internal changes addi tion three might have Brisighella balanced flywheel installed making six varia tionsand confusion reigns supreme IZhZI7~TZD TZ GTZTZG ZZ Engine20-820-820-1020-1020-1020-1222-622-622-822-822-1022-1016-6 Idle RPM200018001800170018001500170017001500160013001400 Top RPM550053005000500050004000500056004600500039004000 oThrustinlb17171551651651216517516171314 U Idle RPM2000 1800 1800 1800 1800 1500 1700 1700 1500 1600 1300 14002000 U Top RPM5300 5300 5000 5000 5000 4300 5100 5300 4800 5000 4100 45008000 oThrustinlb175 175 165 165 1714175 175 1817151616 U Idle RPM2000 2000 1900 1900 1900 1800 2000 2000 1900 2000 1800 18002200 U C Top RPM5200 5400 5000 5100 5100 4200 5300 5800 5000 5000 4000 41008200 OThrustinlb175 175 16165 175 125 17185 17175 151517 y modelB rmediateC st model 30 Model Aviation Left latest model Uuadra left earliest right Note change top cylinder cleaner shiny cast ing new model Right useful accessories available Shown new model CB Associates mount six-bolt prop adapter Original sand-cast mount weighs 6% oz latest die-cast version weighs 4% oz aluminum hub weighs same steel original Supplier Trail Manufacturing PO Box 549 Huron Park Ont Can Original use Chainsaw Price $13995 Availability Dealers & mail order Mfg Trail Manufacturing Weight 3 lb 13 oz no mount TEST DATA SUMMARY Max thrust 195 lb @ 6800 rpm Zinger 20-6 Kolbo 20-5 161 fuel mix @ 89 oz/min fuel consumption Accessories supplied Engine mount No Prop hub Center bolt 5/16-24 Muffler Chainsaw-type Other None Additional items required excluding prop fuel tank Engine mount right-angle throttle linkage Recommended propeller 16-6 205 Recommended fuel mix 161 Carburetor Make type Waibro diaphram fuel pump Controls available Throttle Adjustments avail Idle stop screw high low mixture Ignition Type Magneto mechanical points Spark plug Champion RCJ8Recommended gap 0025 Magneto gap 010 inPoint gap 0015 Kill disable system None suppliedmag ground easily added Internal details Induction Direct piston porting Cylinder Cast machined aluminum Piston rings Cast machined aluminumone ring Crankshaft One piece cast steel Bearings Caged rollerfront rear Conrod Stamped steel plate Bearings Roller bearing crankpin Dimensions Orientation dimensions looking forward along crankshaft upright engine Prop refers propeller back side 1 Firewall prop mount supplied 6-1/16 rear shaft prop 2 Prop rearmost point excluding rear shaft 5-3/4 plug 3 Prop forwardmost point 1 magneto 4 Maximum extension thrust line 5-3/16 plug @ 5/2 behind prop 5 Vertical dimensions thrust line a Up 5-3/16 plug @5 behind prop b Down 1-3/4 flywheel @1% behind prop 6 Horizontal extension thrust line 3-11/16 carb @2 behind prop 7 Propeller hub diameter 0975 in Bolt hole diameter NA 8 Propeller washer 1 dia aluminum -in thick 9 Mounting bolt pattern Depends mount used Subjective items following beyond ability measure di rectly off ered opinions what worth 1 Overall appearance Typical chainsaw engine compact 2 Amount quality instructions Three pages little specif ic technical information Instructions being revised thistime 3 Ease starting a Cold Good 15 20 flips b Hot Excellent 1 5 flips 4 Ease mounting control hook-up Recommend use com mercially-available mount vertical throttle requires bellcrank 5 Ease carburetor adjustments Only idle screw accesible engine running 6 Vibration levels Noticeable excessive 7 Cowlability Rear exhaust side-mounted carb can cause prob lems smaller models 8 Crankshaft bearing slop Obviousmost pronounced engines tested part Big Bangers will try clear up some confusion Before getting Quadra however want make few comments apply test series general 1 Keep mind static thrust doesnt tell whole story about engine/propeller/aircraft combination Before through plan report in-flight experience engines props can 2 engines run mufflers though know little back pressure usually helps Since didnt have mufflers al/the engines felt would better use 3 nature test equipment thrust figures precise rpm figures lucky read rpm can read thrust 025 lb Dont get upset see things results like two different thrust readings same prop apparently same rpm Now lets talk Quadras Quadra manufactured Canada Trail Manufacturing Ltd Trail produces several products powered small gasoline engines Quadra based smaller chainsaw engines has around some time chainsaw certain amount engine vibration tolerable can useful miniature aircraft Early big bird buffs welcomed power available Quadra soon found along power came vibration could did shake planes apart Shock absorbing motor mounts tighter rugged construction techniques quickly developed cope situation modeler Dario Brisighella went step farther attacked source problem no way get rid engine vibration especially single-cylinder engine However since some vibration due ZDT ZDTZ T Z K TZDProp 16-818-618-618618-818-818-818-10 18-10 20-520620-620-8Engine 2000200018002000200019001900180017001800200020002000Idle RPM 7600680076006900670068007000600060006700600066006000Top RPM 15515518175161751716161918185175Thrustinlb 2000200018002000190020001900180017001800200020002000Idle RPM0 780068007800710069006900__7000600061006700600069006000Top RPM 175 165 19 185 17 19 19 17 165 195 175 195 175 Thrustinlb 2200220023002300220022002100200021002200200022002200Idle RPM 0 7900 6800 7800 7000 6900 6900 7000 6000 6100 6800 6000 6800 6000Top RPM 175 16 18 175 17 175 18 17 17 195 18 195 175 Thrust lb D thrust G h K o T Flite Z er July 1981 31 QUADRA ENGINE DATA Latest Version Displacement 2 Cu dynamic imbalances crankshaft/con rod piston system Dario reasoned properly unbalanced flywheel could help balance total ystem idea successful enough Dario now offers modification commercial basis Please note overbalancing simple process requires equipment knowhow available us addition Brisighella balanced flywheel usable Quadra engine other engine likely increase vibration decrease Darios modification has become popular Trail looked year ago introduced Quadra model factory balanced flywheel should confused Danas flywheel Possibly legal economic reasons Trail cannot exactly what Dana does vibration under reasonably good control Quadra influential explosive growth Giant Scale activity growth came new engines compete marketplace product has con tinually improved latest version Quadra result Trail Manufacturings desire maintain position Giant Scale activities following portion letter Bob Cooper af Trail describing changes .. External changesi Elimination peak cooling fins above spark plug boss 2 Elimi nation cooling fin flashing along mold separation line 3 mounting screw lands have gusset supports increased strength 4 Exhaust port carburetor mounting faces have increased size add strength . Internalchanges 1 Bypass ports have increased size deflection angles changed 2 New connecting rod being used 3 New crankshaft being incorporated addition letter Bob sent two engines use tests early model original flywheel other latest version first Quadra turned Out ta intermediate version now have complete set tell apart obvious external difference between latest Quadra earlier models lack vertical cooling fins top ofthe head reliable identifier however since modelers have removed fins themselves new old engine side side cleaner fins beefed up screw lands obvious addition new castings have slightly shiny finish old ones have matte sandblasted appearance internal differences difficult detect eye Thats surprising since minute differences things like porting angles can significant Mare sophisticated equipment have available would required get meaningful data Bob Cooper concerned about disas sembling engines points out instructions warn against doing agree no reason average modeler get inside engine Bobs concern linked fact crankshaft bearings clamped place upper lower crankcase castings bearings proper ly located during reassembly improper crank shaft end-play results can lead lowered performance reassemble engines have recommended three- five-thou sandths inch end-play crankshaft Crankshaft end-play should confused what refer crankshaft bearing slop slop mean amount shaft can moved right angles thrust line End-play movement along thrust line engine needs small finite amount slop particularly important engines large flywheels because less slop smaller magneto air-gap can means spark will hotter engine will start run better test data presented recorded same day Engine B same engine included first report re-ran tests along C conditions would similar possible addition some rpm figures first Quadra B runs now suspect unavoidable difference between B other two total running time opinion difference break-in time significant Engine B seemed have slight edge performance C coming strong its running time increased Comparing C engine C newest version showed slightly better performance importantly improving increased running time After completion initial test series engine run Dario Brisighellas overbalanced flywheels found no signifi cant difference recordable performance have some subjective impressions no real difference top rpm thrust idling improved No obvious differ ence virbration could identified feel going apparent engine airframe reserving judg ment point temporarily both building Quadra-powered planes modeler weve talked has used Danas flywheel reports decreased vibration save space avoid boredom including data sheet newest engine since three versions almost identi cal few differences listed below 1 engine B maximum extension thrust line top fin 5 3s behind prop 2 engine maximum thrust 19 lb Kolbo 20-5 3 engines B fuel consumption ounce per minute authors primary result portion test series greatly increased Continued page 110 32 Model Aviation Three different flywheels Quadra original left factory-balanced centeridentifiable two nail heads oppositethe magnets Brisighella flywheel right Back sides latest stock Quadra flywheel left Brisighella overbalanced flywheel right Overbalancing requiresequipment available modelers photos Bob Beckman ndiub tile various manufacturers Big Banger project has commercial props available test runs Included Dynathrust Grish Kolbo Top Flite Zinger FEATURES INCLUDE Space battery & meter panel Transmitter compartment Room gallon fuel MASIER AIRSC1U Ii FLIGHTBOX KIT Master Airscrew Flight Box has features larger boxes compact handy arrangement parts cut imported mahogany plywood will take stain varnish paint finishes overall size 19Wx9Y2x 12 high $3at dealer 495 postpaid California add 6% Sales Tax Propeller storage Gravity closed small parts storage 7/8 aluminum handle Complete instructions & fasteners WINDSOR PROPELLER CO PO Box 112Windsor CA 95492 joe6e1sewA.dzeexf&zt WRITE FOR COMPLETE PRODUCT LISTING MANUFACTURERS AND DEALERS INQUIRIES INVITED SPECIAL SIZES AVAILABLE ADD $300 FOR POSTAGE AND HANDLING NMG MODELS INC P 0 BOX 396 BY MD 20657 301 326-2554 surface before second applied Koverall will seal fill two three Coats K&B nitrate dope combination accepts polyure thane paints no blistering peeling wing tail surfaces can also covered Koverall highly durable structurally strong inexpensive finish However wings tail sufficently rigid safe use sucfi films MonoKote Im sure about lower temperature films however Flying thorough check-out systems components should conducted leisurely pace home Once everything working per fectly haul yourself Rearwin Junior nearest flying field prepared have ball Ground handling squirrely BALSA SHEETS 4x48x/ie49 4x48x3A3252 4x48x%62 4x48x3/1674 4x48x90 4x48x/2108 6x48x/it74 6x48x3A3278 6x48x/893 6x48x135 6X48x/2162 PLYWOOD 6x48xA32125 6x48x/ie136 6x48x3A32175 6x48x/a185 6x48x3/16240 6x48x280 BALSA BLOCKS 1x2x2462 1x3x2486 1x4x24126 2x2x2486 2x3x24126 3x3x24240 tail-dragger Just advance throttle slowly until rudder gets bite air As throttle advanced will break ground little need up elevator Turns rudder-only gentle slightly reverse rudder control level wings ailerons model requires some opposite rud der counteract dihedral particularly left turn Landings slow gentle needs line up runway about 150 ft out 30 ft high retard throttle let float glide such may have resort down elevator get wheels Onto grass Junior has natural tendency land three-point attitude sufficient speed burned off airplane can flown anyone has 110 Model Aviation bit stick time Old-Timer Stalls mushy havent able spin has no tendency snap low speed nor pitch high speed Rearwin Junior flies like heavy Old-Timer RC assistnot surprising development thats really what Build yourself construction simple strong flies beautifully Most amazingly realistic air fun-to-work ratio design leans strongly fun side Enjoy References Aviation History Greater Kansas City Cub Flyers Publications Library Congress Catalog No 74-119630 Lightplanes Since 1909 John Underwood George Collinge Heritage Press Library Congress Catalog No 69-17709 Air Progress January 1968 Wonder ful Rearwins Some Giant Birds John W Underwood Vintage Veteran Aircraft Guide John Underwood Collinwood Press Library Congress Catalog No 68-28978 Collect-Air Photos PO Box 14234 Milwau kee WI 53214 set No 136 Big Bangers/Beckman Continued page 32 respect Quadra its capabilities three engines easy starting Thrust outputs some cases surprisingly high improving running time Vibration levels excessive lower some other chainsaw-derived engines added considerations availability price its hard beat wish thank following support portion project Dario Brisighella 1032 East Manitowoc Ave Oak Creek WI 53154 CB Associates Inc 21658 Cloud Way Hay ward CA 94545 Dynathrust Props Inc 2541 NE 11th Court Pompano Beach FL 33062 Grish Bros St John IN 46373 JZ ProductsZinger 25029S Vermont Ave Harbor City CA 90710 Top Flite Models Inc 1901 Narragansett Ave Chicago IL 60639 Trail Manufacturing Ltd Huron Park Ont NOM lYO Canada H ELI- FLI/Burdin Continued page 37 doing maneuver correctly wdrd flight will come Level V get practice basics finished calm weather practice go back repeat Level IV ma neuvers light breeze JS Dont think trying circle-arounds wind until previous work has practiced windy conditions wind direction will constant its effect Helicopter will continously change fly around circle Approach maneuver same caution did first circle-around practice wind emphasized level unless learn youll always waiting calm day evening youll get little flying JS finally comfortable wind various orientations its time remove training gear return original factory-supplied equipment will some obvious changes machines performance THE CHEROKEE THE REAPER BalsaBalsa Fuselage Fast Assembly S/ow FlyingSheeted Foam Core Wing 3-4 Channels4-6 Channels 19-25 Engine40-60 Engine $6995
Edition: Model Aviation - 1981/07
Page Numbers: 30, 31, 32, 110
Beckman Kirby Crawford Ii angers foi Quadra engine greater use other Giant Scale engine type has around longer Actually have three variations Quadra through years authors provide much data Part 2 SCRATCH majority Giant Scale models youll uncover Quadra under cowl quite few big bangers available now Quadra first appear real quantity Literally thousands now use Most Giant Scale kits market designed Quadra since about thing around kits developed two three years ago blocky looking Canadian chainsaw engine has con tinues have tremendous influence whole Giant Scale field Part series included version Quadra basically three slightly differ ent versions market original model version factory balanced flywheel latest model minor external changes some significant internal changes addi tion three might have Brisighella balanced flywheel installed making six varia tionsand confusion reigns supreme IZhZI7~TZD TZ GTZTZG ZZ Engine20-820-820-1020-1020-1020-1222-622-622-822-822-1022-1016-6 Idle RPM200018001800170018001500170017001500160013001400 Top RPM550053005000500050004000500056004600500039004000 oThrustinlb17171551651651216517516171314 U Idle RPM2000 1800 1800 1800 1800 1500 1700 1700 1500 1600 1300 14002000 U Top RPM5300 5300 5000 5000 5000 4300 5100 5300 4800 5000 4100 45008000 oThrustinlb175 175 165 165 1714175 175 1817151616 U Idle RPM2000 2000 1900 1900 1900 1800 2000 2000 1900 2000 1800 18002200 U C Top RPM5200 5400 5000 5100 5100 4200 5300 5800 5000 5000 4000 41008200 OThrustinlb175 175 16165 175 125 17185 17175 151517 y modelB rmediateC st model 30 Model Aviation Left latest model Uuadra left earliest right Note change top cylinder cleaner shiny cast ing new model Right useful accessories available Shown new model CB Associates mount six-bolt prop adapter Original sand-cast mount weighs 6% oz latest die-cast version weighs 4% oz aluminum hub weighs same steel original Supplier Trail Manufacturing PO Box 549 Huron Park Ont Can Original use Chainsaw Price $13995 Availability Dealers & mail order Mfg Trail Manufacturing Weight 3 lb 13 oz no mount TEST DATA SUMMARY Max thrust 195 lb @ 6800 rpm Zinger 20-6 Kolbo 20-5 161 fuel mix @ 89 oz/min fuel consumption Accessories supplied Engine mount No Prop hub Center bolt 5/16-24 Muffler Chainsaw-type Other None Additional items required excluding prop fuel tank Engine mount right-angle throttle linkage Recommended propeller 16-6 205 Recommended fuel mix 161 Carburetor Make type Waibro diaphram fuel pump Controls available Throttle Adjustments avail Idle stop screw high low mixture Ignition Type Magneto mechanical points Spark plug Champion RCJ8Recommended gap 0025 Magneto gap 010 inPoint gap 0015 Kill disable system None suppliedmag ground easily added Internal details Induction Direct piston porting Cylinder Cast machined aluminum Piston rings Cast machined aluminumone ring Crankshaft One piece cast steel Bearings Caged rollerfront rear Conrod Stamped steel plate Bearings Roller bearing crankpin Dimensions Orientation dimensions looking forward along crankshaft upright engine Prop refers propeller back side 1 Firewall prop mount supplied 6-1/16 rear shaft prop 2 Prop rearmost point excluding rear shaft 5-3/4 plug 3 Prop forwardmost point 1 magneto 4 Maximum extension thrust line 5-3/16 plug @ 5/2 behind prop 5 Vertical dimensions thrust line a Up 5-3/16 plug @5 behind prop b Down 1-3/4 flywheel @1% behind prop 6 Horizontal extension thrust line 3-11/16 carb @2 behind prop 7 Propeller hub diameter 0975 in Bolt hole diameter NA 8 Propeller washer 1 dia aluminum -in thick 9 Mounting bolt pattern Depends mount used Subjective items following beyond ability measure di rectly off ered opinions what worth 1 Overall appearance Typical chainsaw engine compact 2 Amount quality instructions Three pages little specif ic technical information Instructions being revised thistime 3 Ease starting a Cold Good 15 20 flips b Hot Excellent 1 5 flips 4 Ease mounting control hook-up Recommend use com mercially-available mount vertical throttle requires bellcrank 5 Ease carburetor adjustments Only idle screw accesible engine running 6 Vibration levels Noticeable excessive 7 Cowlability Rear exhaust side-mounted carb can cause prob lems smaller models 8 Crankshaft bearing slop Obviousmost pronounced engines tested part Big Bangers will try clear up some confusion Before getting Quadra however want make few comments apply test series general 1 Keep mind static thrust doesnt tell whole story about engine/propeller/aircraft combination Before through plan report in-flight experience engines props can 2 engines run mufflers though know little back pressure usually helps Since didnt have mufflers al/the engines felt would better use 3 nature test equipment thrust figures precise rpm figures lucky read rpm can read thrust 025 lb Dont get upset see things results like two different thrust readings same prop apparently same rpm Now lets talk Quadras Quadra manufactured Canada Trail Manufacturing Ltd Trail produces several products powered small gasoline engines Quadra based smaller chainsaw engines has around some time chainsaw certain amount engine vibration tolerable can useful miniature aircraft Early big bird buffs welcomed power available Quadra soon found along power came vibration could did shake planes apart Shock absorbing motor mounts tighter rugged construction techniques quickly developed cope situation modeler Dario Brisighella went step farther attacked source problem no way get rid engine vibration especially single-cylinder engine However since some vibration due ZDT ZDTZ T Z K TZDProp 16-818-618-618618-818-818-818-10 18-10 20-520620-620-8Engine 2000200018002000200019001900180017001800200020002000Idle RPM 7600680076006900670068007000600060006700600066006000Top RPM 15515518175161751716161918185175Thrustinlb 2000200018002000190020001900180017001800200020002000Idle RPM0 780068007800710069006900__7000600061006700600069006000Top RPM 175 165 19 185 17 19 19 17 165 195 175 195 175 Thrustinlb 2200220023002300220022002100200021002200200022002200Idle RPM 0 7900 6800 7800 7000 6900 6900 7000 6000 6100 6800 6000 6800 6000Top RPM 175 16 18 175 17 175 18 17 17 195 18 195 175 Thrust lb D thrust G h K o T Flite Z er July 1981 31 QUADRA ENGINE DATA Latest Version Displacement 2 Cu dynamic imbalances crankshaft/con rod piston system Dario reasoned properly unbalanced flywheel could help balance total ystem idea successful enough Dario now offers modification commercial basis Please note overbalancing simple process requires equipment knowhow available us addition Brisighella balanced flywheel usable Quadra engine other engine likely increase vibration decrease Darios modification has become popular Trail looked year ago introduced Quadra model factory balanced flywheel should confused Danas flywheel Possibly legal economic reasons Trail cannot exactly what Dana does vibration under reasonably good control Quadra influential explosive growth Giant Scale activity growth came new engines compete marketplace product has con tinually improved latest version Quadra result Trail Manufacturings desire maintain position Giant Scale activities following portion letter Bob Cooper af Trail describing changes .. External changesi Elimination peak cooling fins above spark plug boss 2 Elimi nation cooling fin flashing along mold separation line 3 mounting screw lands have gusset supports increased strength 4 Exhaust port carburetor mounting faces have increased size add strength . Internalchanges 1 Bypass ports have increased size deflection angles changed 2 New connecting rod being used 3 New crankshaft being incorporated addition letter Bob sent two engines use tests early model original flywheel other latest version first Quadra turned Out ta intermediate version now have complete set tell apart obvious external difference between latest Quadra earlier models lack vertical cooling fins top ofthe head reliable identifier however since modelers have removed fins themselves new old engine side side cleaner fins beefed up screw lands obvious addition new castings have slightly shiny finish old ones have matte sandblasted appearance internal differences difficult detect eye Thats surprising since minute differences things like porting angles can significant Mare sophisticated equipment have available would required get meaningful data Bob Cooper concerned about disas sembling engines points out instructions warn against doing agree no reason average modeler get inside engine Bobs concern linked fact crankshaft bearings clamped place upper lower crankcase castings bearings proper ly located during reassembly improper crank shaft end-play results can lead lowered performance reassemble engines have recommended three- five-thou sandths inch end-play crankshaft Crankshaft end-play should confused what refer crankshaft bearing slop slop mean amount shaft can moved right angles thrust line End-play movement along thrust line engine needs small finite amount slop particularly important engines large flywheels because less slop smaller magneto air-gap can means spark will hotter engine will start run better test data presented recorded same day Engine B same engine included first report re-ran tests along C conditions would similar possible addition some rpm figures first Quadra B runs now suspect unavoidable difference between B other two total running time opinion difference break-in time significant Engine B seemed have slight edge performance C coming strong its running time increased Comparing C engine C newest version showed slightly better performance importantly improving increased running time After completion initial test series engine run Dario Brisighellas overbalanced flywheels found no signifi cant difference recordable performance have some subjective impressions no real difference top rpm thrust idling improved No obvious differ ence virbration could identified feel going apparent engine airframe reserving judg ment point temporarily both building Quadra-powered planes modeler weve talked has used Danas flywheel reports decreased vibration save space avoid boredom including data sheet newest engine since three versions almost identi cal few differences listed below 1 engine B maximum extension thrust line top fin 5 3s behind prop 2 engine maximum thrust 19 lb Kolbo 20-5 3 engines B fuel consumption ounce per minute authors primary result portion test series greatly increased Continued page 110 32 Model Aviation Three different flywheels Quadra original left factory-balanced centeridentifiable two nail heads oppositethe magnets Brisighella flywheel right Back sides latest stock Quadra flywheel left Brisighella overbalanced flywheel right Overbalancing requiresequipment available modelers photos Bob Beckman ndiub tile various manufacturers Big Banger project has commercial props available test runs Included Dynathrust Grish Kolbo Top Flite Zinger FEATURES INCLUDE Space battery & meter panel Transmitter compartment Room gallon fuel MASIER AIRSC1U Ii FLIGHTBOX KIT Master Airscrew Flight Box has features larger boxes compact handy arrangement parts cut imported mahogany plywood will take stain varnish paint finishes overall size 19Wx9Y2x 12 high $3at dealer 495 postpaid California add 6% Sales Tax Propeller storage Gravity closed small parts storage 7/8 aluminum handle Complete instructions & fasteners WINDSOR PROPELLER CO PO Box 112Windsor CA 95492 joe6e1sewA.dzeexf&zt WRITE FOR COMPLETE PRODUCT LISTING MANUFACTURERS AND DEALERS INQUIRIES INVITED SPECIAL SIZES AVAILABLE ADD $300 FOR POSTAGE AND HANDLING NMG MODELS INC P 0 BOX 396 BY MD 20657 301 326-2554 surface before second applied Koverall will seal fill two three Coats K&B nitrate dope combination accepts polyure thane paints no blistering peeling wing tail surfaces can also covered Koverall highly durable structurally strong inexpensive finish However wings tail sufficently rigid safe use sucfi films MonoKote Im sure about lower temperature films however Flying thorough check-out systems components should conducted leisurely pace home Once everything working per fectly haul yourself Rearwin Junior nearest flying field prepared have ball Ground handling squirrely BALSA SHEETS 4x48x/ie49 4x48x3A3252 4x48x%62 4x48x3/1674 4x48x90 4x48x/2108 6x48x/it74 6x48x3A3278 6x48x/893 6x48x135 6X48x/2162 PLYWOOD 6x48xA32125 6x48x/ie136 6x48x3A32175 6x48x/a185 6x48x3/16240 6x48x280 BALSA BLOCKS 1x2x2462 1x3x2486 1x4x24126 2x2x2486 2x3x24126 3x3x24240 tail-dragger Just advance throttle slowly until rudder gets bite air As throttle advanced will break ground little need up elevator Turns rudder-only gentle slightly reverse rudder control level wings ailerons model requires some opposite rud der counteract dihedral particularly left turn Landings slow gentle needs line up runway about 150 ft out 30 ft high retard throttle let float glide such may have resort down elevator get wheels Onto grass Junior has natural tendency land three-point attitude sufficient speed burned off airplane can flown anyone has 110 Model Aviation bit stick time Old-Timer Stalls mushy havent able spin has no tendency snap low speed nor pitch high speed Rearwin Junior flies like heavy Old-Timer RC assistnot surprising development thats really what Build yourself construction simple strong flies beautifully Most amazingly realistic air fun-to-work ratio design leans strongly fun side Enjoy References Aviation History Greater Kansas City Cub Flyers Publications Library Congress Catalog No 74-119630 Lightplanes Since 1909 John Underwood George Collinge Heritage Press Library Congress Catalog No 69-17709 Air Progress January 1968 Wonder ful Rearwins Some Giant Birds John W Underwood Vintage Veteran Aircraft Guide John Underwood Collinwood Press Library Congress Catalog No 68-28978 Collect-Air Photos PO Box 14234 Milwau kee WI 53214 set No 136 Big Bangers/Beckman Continued page 32 respect Quadra its capabilities three engines easy starting Thrust outputs some cases surprisingly high improving running time Vibration levels excessive lower some other chainsaw-derived engines added considerations availability price its hard beat wish thank following support portion project Dario Brisighella 1032 East Manitowoc Ave Oak Creek WI 53154 CB Associates Inc 21658 Cloud Way Hay ward CA 94545 Dynathrust Props Inc 2541 NE 11th Court Pompano Beach FL 33062 Grish Bros St John IN 46373 JZ ProductsZinger 25029S Vermont Ave Harbor City CA 90710 Top Flite Models Inc 1901 Narragansett Ave Chicago IL 60639 Trail Manufacturing Ltd Huron Park Ont NOM lYO Canada H ELI- FLI/Burdin Continued page 37 doing maneuver correctly wdrd flight will come Level V get practice basics finished calm weather practice go back repeat Level IV ma neuvers light breeze JS Dont think trying circle-arounds wind until previous work has practiced windy conditions wind direction will constant its effect Helicopter will continously change fly around circle Approach maneuver same caution did first circle-around practice wind emphasized level unless learn youll always waiting calm day evening youll get little flying JS finally comfortable wind various orientations its time remove training gear return original factory-supplied equipment will some obvious changes machines performance THE CHEROKEE THE REAPER BalsaBalsa Fuselage Fast Assembly S/ow FlyingSheeted Foam Core Wing 3-4 Channels4-6 Channels 19-25 Engine40-60 Engine $6995