Big Bangers for Bigbirds

b Beckman Kirby Crawford hi ban ersfo Giant Scale contributing editor teamed up another noted flier big birds give us good look four gasoline-burners being used power RC biggies Part GIANT SCALE fairly recent term used describe RC aircraft larger what has come tobe considered usual RC model big birds arent really new early days RC took good-sized plane carry radio gear needed modern lightweight equipment came along few dedicated souls stayed large format problem however finding adequate power Giant Scale movement see today didnt really get started until gasoline engines roughly 2 3 cu displacement became readily available some time people converting chain-saw other small engines driving propellers real spark Quadra already converted became available quantity point big birds became miniature aircraft just big chaperoned Free Flight models Giant Scale really took off Today fairly wide selection engines available Giant Scale builders As result newcomers field faced problem deciding power plant Bob Beckmans RC Giant Scale column receives almost daily queries about various plans kits availableand what engine use model er getting ready start new project kitbuilt plan-built scratch-built has lot questions What engine has power need Will fit space have available What mounting bolt pattern does throttle hook-up What need addition engine effort find least some answers authors embarked series engine tests evaluations idea test examine kinds things would easily under stood useful average modeler Things like rpm static thrust fuel consumption physical dimensions weight can measured reported objectively Additional factors interest and/or importance subjective nature beyond ability measure objec tively included clearly identified test procedures deliberately very sophisticated test equipment consists venerable Heathkit Thumb Tach homemade SO-lb capacity thrust measuring test stand 25lb capacity scale weight measurements stopwatch kind setup almost modeler could come up probably wouldnt just two engines expect run 15 20 engines before through current series tests will cover gasoline-burners enough interest may series larger glow engines prop drives intent make imply recom mendations against particular engines What have tried collect make available data potential users need order make informed decisions about Giant Scale power plants big bird engine know capable flying some kind Giant Scale aircraft no engine suitable design hope efforts will help April 1 981 25 opposite page Kirby Crawford taking rpm reading Bob Beckman recording data Above Bob works throttle Kirby flips prop left-handed Project requires lots paraphernalia Note use hearing protectors both Additional tests made later & dealers japan z mci mount 2a-6 prop plate ank None ad fuel mix 321 make proper selection dream bird data engine presented standard forms plus table showing rpm m PROPSDYNATHRUSTTOP FLITEZINGER KOLBOGRISH ENGINES18-6 18-8 20-820-1020-620-8 20-620-52210248 Idler RPM3ee ULIA aij Top RPM7500 7900 6900 590000 6000 72007100 Thrust nib/5 /619/6/6 17/918 Idle 20002000 900 2000 1000 2000 Ci RPM 81007100 6200 7200 600 7900 oo Thrust nib/75215QO52/S221/5 1 Idle~95ct2000200022002000 RPM 5500 Top RPM8i00750060076007000Sooo NThrust2120522522 22 lb173 Idle cRPM2Ooo200520001000100020082000 Top 75000o710070007900c0o05700 oRPM mi. Thu335225 1z525 oh data recorded authors note several seeming anomalies have no explanation present time instance note variations thrust compared rpm forthe different engines tested using Dynathrust 20-8 prop thrust tigures tor engines props involved forms should self-explanatory next few paragraphs describe procedures used Engines engines new disassembled internal pictures inspection obvious no brief check run engine set up run according instructions supplied recommended fuel mix propeller used after initial mixture adjustments tank fuel 14 oz run through 5000 rpm realize does represent com plete break-in engines time facilities available didnt allow luxury Bob Beckman plans make follow-up reports RC Giant Scale column running time experience built up engine Propellers propeller carefully bal anced Only given size make propeller used same prop run engine appropriate writing commercially-available props hand Additional test runs planned can obtained Fuel Regular leaded gasoline used cases Homelite chain-saw engine oil used engines except Kawasaki 26 Model Aviation Bel Ray MC-1 specified cases gas/oil ratio listed particular engine Starting Unless otherwise noted starting done hand wrist arm shoulder get sore found best starting procedure engines cold fully open throttle close choke choke hand no choke engine flip prop through until engine pops reset throttle point just above idle partially open choke continue flipping until engine runs choke gradually opened engine warms up warm engines usually start quickly low throttle setting little no choking Note above procedure usable engine well secured test stand Since possible engine start during choking stage procedure should used engine mounted plane Once experience gained given engine required number choking flips can done ignition off Thrust measurement know static thrust does tell whole story Things change once prop starts moving through air instead just moving air different airplanes can require different props 8 though using same engine However done reasonable care static thrust measure ments can good gauge relative performance both engines propellers Besides us game town Test sequence After initial break-in de scribed above mixture idle adjustments rechecked minimum reliable idle speed maximum high speed good transition Initially done propeller no significant difference could detected final procedure make adjustments once leave subsequent runs sequence followed 1 Measure idle rpm 2 Measure maximum rpm 3 Measure thrust maximum rpm repeated propeller available moving up down size pitch until significant decrease performance identified practical limits engine case larger engines upper limit could identified propellers available us time tests After running propeller produc ing highest thrust used fuel consumption check 1 4-oz tank topped off engine started set top speed stopwatch used time run until tank dry rpm thrust data presented doesnt always match previously-published figures isnt surprising considering variables involved However test runs reported April 1981 27 es goca view testing rig uox secured 1/2-jfl pegs driven ground performed same day using same equipment over time span about four hours during no major changes weather conditions wish thank following firms assistance project CB Associates Inc Kawasaki 21658 Cloud Way Hayward CA 94545 Dynathrust Props Inc 2541 NE 11th Court Pompano Beach FL 33062 Gibbs Hobby & Research Kioritz 6195 BA mci mount rop 161 fuel ation Hillfield St NW North Canton OH 44720 Grish Bros St John IN 46373 Homers Sales Roper 300 Dixie Hwy Beecher IL 60401 Top Flite Models Inc 1901 Narragansett Ave Chicago IL 60639 Trail Manufacturing Ltd Quadra PO Box 549 Huron Park Ont NOM LYO Canada Special Notes Subjective Data model stock flywheel minor mechani cal difficulty throttle plate prevented proper idling during tests Since did affect high-speed operation decided complete rest sequence engine could included report As chain-saw-derived engines Quadra has rear-facing exhaust rear shaft extension shaft originally drove chain Both factors can complicate mounting exhaust routing However available kits plans designed Quadra designers have solved problems consider prop hub supplied engine marginal small diameter face can crush dig prop hub several good replacements available Ron Shettler CB Associates Rual Eng others Kawasaki TA36 engine tested early model crankcase pressure pump supplied internally arrangement re quires positioning carburetor makes adjustment high- low-speed needles difficult engine running Later models TA-S 1 tested utilize external pressure tap adjustments easily accessed Continued page 102 28 Model Aviation ase nd tank Mount Iedfuel mix 161 Quadra engine tested original uaggie os big bangers waiting turns tor testing L-H hoper Kawasaki Kioritz Beckmans home-brew Homelite Quadra Latter original model since has updated twice Radio Technique/Myers Continued page 23 elevator Therefore L~ 525 J 12125 D 371/125 0 Servo torque required T CF F 5 last months chart T--- x94x94x 126x525xoooo5 867 125 In-oz Better use World Engines S-16 Norm George M Myers 70 Froehlich Farm Road Hicksville NY 11801 bulky look engine due rectangular portions crankcase casting can removed turns out weight saved less three ounces doesnt justify machining cost An unusual feature Kawasaki engines cylinder can repositioned 180 degrees normal configuration carb side exhaust other cylinder test engine rotated carb exhaust same side makes horizontal mounting snap cowl like Pitts Kawasaki high quality cool running smooth engine Kioritz engine makes best first impres sion pretty well lives up Like blower-derived engines designed long periods high-speed running opposed chain-saws short bursts addition Kengines usual application requires low vibration Both design goals fit requirements perfectly significantly different respects Kioritz shares characteristic Quadra carburetors have built-in chokes Hand-choking can awkward downright dangerous un-cowled engine practically impossible inside cowl Dario Brisighella has available add-on choke Quadra probably will fit just well Kioritz relatively high fuel consumption figure suspect due noticeable amount fuel drawn out carb air intake running ram-air scoop carb should result slightly leaner mixture settings better fuel consumption Kioritz smooth cool running high quality engine Roper maximum displacement engine current test series would expect measurements maxi mum also did have maximum thrust measurements werent really able identify peak props available did have maximum weight physical dimensions didnt have maximum fuel consumption see Kioritz notes did have maximum vibration levels first time ran engine shaking much couldnt get screwdriver otherwise easily accessible mixture screws stop engine make changes low-speed mixture until got things calmed down Once mixture set properly engine warmed up smoothed out nicely Ropers vibration relatively high especially idle does detract significantly engines usefulness struck size-to-displacement ratio engine requires very little space Quadra large flywheel close behind prop does mean need fairly flat-faced cowl longer prop adapter would simplify getting engine tapering cowl carb has external pressure pick-up can rotated 180 degrees places mixture adjustments face forward would accessible cowled engine though could accessed engine running completes Part report Unfortun 102 Model Aviation .yASINII AIRSCIU lIT PRESENTS BALSA STRIPPER PRECISION STRIP WOOD TO x INS FROM BALSA SHEET ALSO FOR DRAFTING AND PHOTO MATS USES TYPE II BLADE SUPER TOOL T PRICE WINDSOR PROPELLER CO PO BOX 112 WINDSOR CA 95492 Heres equipment need give psur props toe very best balance--balance directions Carefully crafted top grade materials BUBBLE BALArtJCER accomodates 3/161/49/32 prop holes Other sizes available special order Dealers oivited $1495 Add $150 HOWARD B HUEBL DEPT 055 postage handling ft Mien add 4% sales tax No CD0s Boo 193 Route 4 Mankato Mn 56931 Big Bangers/Beckman Continued page 28 ately Part II will appear next month December written tem perature outside just over 10 degrees thats Celsius next chapter continuing story will have wait avail ability both equipment decent weather hope information presented will use will add soon possible RC Aerobatics/Van Putte Continued page 33 ing comments about flying high altitude has some interesting news us fly near sea level Randy wrote Im compelled send another side altitude story elevation 6000 ft used Lanier Sb Comets 35s Falcon 56s 19s 25s learn sans instructors five years back Theres no lack power fact Sb Comet will fly Enya 35 sleeve turned 1800 1 did flew poorly sure flying Senior Falcons Lanier Comets 40s 60s Sig Kadets 30s 35s Some 40 60 sport birds fly better 60s heavy built right fly fine 40 will admit altitude affects aircraft per formance might throw contest flier off game try play big motor altitude difference too heavy have lot guys learning fly 25 35 trainer 40 45 hot ship beginner Trims change change throttle land hot guys Florida California wher ever bring birds fly Rockies Strips scarce west side flying great Thanks inside story Randy Ron Van Putte 111 Sleepy Oaks Rd Fort Walton Beach FL 32548 RC Soaring/Pruss Continued page 37 least three British fliers still process selecting team group Austria Germany Switzer land have formed 1SF International Soaring Forum weekend before ClAM over 80 modelers above-mentioned countries met discussed design construction techniques airfoils 68-page report resulted report three-view Spartakus presented month thanks Hansruedi Schlapfer Switzerland Years ago three-task concept came scene USAs approach treat distance task involved thermal ing order get sufficient altitude turn get maximum distance during four-minute flight Most Europeans went other route began design slick machines would fly 12-lap course just virtue slippery lines Designers Spattakus boast LID nearly 20/1 ratio doesnt jostle 10-minute duration design envelope ponder standard 150-meter launch straightline distance 3000 meters Orwell over mile can flown no-wind condition Put F3B Distance-task perspective means nearly 20 laps could flown Wing construction alone could feature design article Ill pass just few points now Construction similar mentioned Continued page 104 MEW oo pR@ U3 Quadra McCulloch Super Hustler new prop hub will fit any e engines ones 5/1 6-24 shaft Bolt plate serves drill jig aod tapped spinner bolt Only $1995ROUSH MFG Dealer ributorP0 Box 251 Inquiries WelcomeSandyville Ohio 44671 C Catalog entie tine airplane Control line model lids P C scale Trainer kits boat model kits accessories etc SO enciosee Name __________________________ ______________________________ City Free-Flight fl/C Assist SUPER BRIGADIER 66 Plan SetSpanFo 15 ta 25 Pawor 2-4 channel 8/C Old favorite #RCFF 2 $995 RIC version has ailerons SUPER BRIGADIER 44 1 /2A A/C Fre-Flight AssistPlan 44 Span qor A/C Training#RC Set $ Prices tor Complete Plans Sub Assembly Detailed Parts Lists Add $200 tor Mailing Tube Send $100 retundable tor Complete Information Kits some really great things come S.: April 1981 103 STEELING MODELS BUILDING 3620 G StreetPhiladelphia Pa 19134 BASEBALL CAPSINTRODUCTORY OFFER See club emblem printed full color comfortable sport caps Order Now $500 ea Send catalog & quantity disc ______e 2021-B THIRD STREET RIVERSIDE CA 92507

b Beckman Kirby Crawford hi ban ersfo Giant Scale contributing editor teamed up another noted flier big birds give us good look four gasoline-burners being used power RC biggies Part GIANT SCALE fairly recent term used describe RC aircraft larger what has come tobe considered usual RC model big birds arent really new early days RC took good-sized plane carry radio gear needed modern lightweight equipment came along few dedicated souls stayed large format problem however finding adequate power Giant Scale movement see today didnt really get started until gasoline engines roughly 2 3 cu displacement became readily available some time people converting chain-saw other small engines driving propellers real spark Quadra already converted became available quantity point big birds became miniature aircraft just big chaperoned Free Flight models Giant Scale really took off Today fairly wide selection engines available Giant Scale builders As result newcomers field faced problem deciding power plant Bob Beckmans RC Giant Scale column receives almost daily queries about various plans kits availableand what engine use model er getting ready start new project kitbuilt plan-built scratch-built has lot questions What engine has power need Will fit space have available What mounting bolt pattern does throttle hook-up What need addition engine effort find least some answers authors embarked series engine tests evaluations idea test examine kinds things would easily under stood useful average modeler Things like rpm static thrust fuel consumption physical dimensions weight can measured reported objectively Additional factors interest and/or importance subjective nature beyond ability measure objec tively included clearly identified test procedures deliberately very sophisticated test equipment consists venerable Heathkit Thumb Tach homemade SO-lb capacity thrust measuring test stand 25lb capacity scale weight measurements stopwatch kind setup almost modeler could come up probably wouldnt just two engines expect run 15 20 engines before through current series tests will cover gasoline-burners enough interest may series larger glow engines prop drives intent make imply recom mendations against particular engines What have tried collect make available data potential users need order make informed decisions about Giant Scale power plants big bird engine know capable flying some kind Giant Scale aircraft no engine suitable design hope efforts will help April 1 981 25 opposite page Kirby Crawford taking rpm reading Bob Beckman recording data Above Bob works throttle Kirby flips prop left-handed Project requires lots paraphernalia Note use hearing protectors both Additional tests made later & dealers japan z mci mount 2a-6 prop plate ank None ad fuel mix 321 make proper selection dream bird data engine presented standard forms plus table showing rpm m PROPSDYNATHRUSTTOP FLITEZINGER KOLBOGRISH ENGINES18-6 18-8 20-820-1020-620-8 20-620-52210248 Idler RPM3ee ULIA aij Top RPM7500 7900 6900 590000 6000 72007100 Thrust nib/5 /619/6/6 17/918 Idle 20002000 900 2000 1000 2000 Ci RPM 81007100 6200 7200 600 7900 oo Thrust nib/75215QO52/S221/5 1 Idle~95ct2000200022002000 RPM 5500 Top RPM8i00750060076007000Sooo NThrust2120522522 22 lb173 Idle cRPM2Ooo200520001000100020082000 Top 75000o710070007900c0o05700 oRPM mi. Thu335225 1z525 oh data recorded authors note several seeming anomalies have no explanation present time instance note variations thrust compared rpm forthe different engines tested using Dynathrust 20-8 prop thrust tigures tor engines props involved forms should self-explanatory next few paragraphs describe procedures used Engines engines new disassembled internal pictures inspection obvious no brief check run engine set up run according instructions supplied recommended fuel mix propeller used after initial mixture adjustments tank fuel 14 oz run through 5000 rpm realize does represent com plete break-in engines time facilities available didnt allow luxury Bob Beckman plans make follow-up reports RC Giant Scale column running time experience built up engine Propellers propeller carefully bal anced Only given size make propeller used same prop run engine appropriate writing commercially-available props hand Additional test runs planned can obtained Fuel Regular leaded gasoline used cases Homelite chain-saw engine oil used engines except Kawasaki 26 Model Aviation Bel Ray MC-1 specified cases gas/oil ratio listed particular engine Starting Unless otherwise noted starting done hand wrist arm shoulder get sore found best starting procedure engines cold fully open throttle close choke choke hand no choke engine flip prop through until engine pops reset throttle point just above idle partially open choke continue flipping until engine runs choke gradually opened engine warms up warm engines usually start quickly low throttle setting little no choking Note above procedure usable engine well secured test stand Since possible engine start during choking stage procedure should used engine mounted plane Once experience gained given engine required number choking flips can done ignition off Thrust measurement know static thrust does tell whole story Things change once prop starts moving through air instead just moving air different airplanes can require different props 8 though using same engine However done reasonable care static thrust measure ments can good gauge relative performance both engines propellers Besides us game town Test sequence After initial break-in de scribed above mixture idle adjustments rechecked minimum reliable idle speed maximum high speed good transition Initially done propeller no significant difference could detected final procedure make adjustments once leave subsequent runs sequence followed 1 Measure idle rpm 2 Measure maximum rpm 3 Measure thrust maximum rpm repeated propeller available moving up down size pitch until significant decrease performance identified practical limits engine case larger engines upper limit could identified propellers available us time tests After running propeller produc ing highest thrust used fuel consumption check 1 4-oz tank topped off engine started set top speed stopwatch used time run until tank dry rpm thrust data presented doesnt always match previously-published figures isnt surprising considering variables involved However test runs reported April 1981 27 es goca view testing rig uox secured 1/2-jfl pegs driven ground performed same day using same equipment over time span about four hours during no major changes weather conditions wish thank following firms assistance project CB Associates Inc Kawasaki 21658 Cloud Way Hayward CA 94545 Dynathrust Props Inc 2541 NE 11th Court Pompano Beach FL 33062 Gibbs Hobby & Research Kioritz 6195 BA mci mount rop 161 fuel ation Hillfield St NW North Canton OH 44720 Grish Bros St John IN 46373 Homers Sales Roper 300 Dixie Hwy Beecher IL 60401 Top Flite Models Inc 1901 Narragansett Ave Chicago IL 60639 Trail Manufacturing Ltd Quadra PO Box 549 Huron Park Ont NOM LYO Canada Special Notes Subjective Data model stock flywheel minor mechani cal difficulty throttle plate prevented proper idling during tests Since did affect high-speed operation decided complete rest sequence engine could included report As chain-saw-derived engines Quadra has rear-facing exhaust rear shaft extension shaft originally drove chain Both factors can complicate mounting exhaust routing However available kits plans designed Quadra designers have solved problems consider prop hub supplied engine marginal small diameter face can crush dig prop hub several good replacements available Ron Shettler CB Associates Rual Eng others Kawasaki TA36 engine tested early model crankcase pressure pump supplied internally arrangement re quires positioning carburetor makes adjustment high- low-speed needles difficult engine running Later models TA-S 1 tested utilize external pressure tap adjustments easily accessed Continued page 102 28 Model Aviation ase nd tank Mount Iedfuel mix 161 Quadra engine tested original uaggie os big bangers waiting turns tor testing L-H hoper Kawasaki Kioritz Beckmans home-brew Homelite Quadra Latter original model since has updated twice Radio Technique/Myers Continued page 23 elevator Therefore L~ 525 J 12125 D 371/125 0 Servo torque required T CF F 5 last months chart T--- x94x94x 126x525xoooo5 867 125 In-oz Better use World Engines S-16 Norm George M Myers 70 Froehlich Farm Road Hicksville NY 11801 bulky look engine due rectangular portions crankcase casting can removed turns out weight saved less three ounces doesnt justify machining cost An unusual feature Kawasaki engines cylinder can repositioned 180 degrees normal configuration carb side exhaust other cylinder test engine rotated carb exhaust same side makes horizontal mounting snap cowl like Pitts Kawasaki high quality cool running smooth engine Kioritz engine makes best first impres sion pretty well lives up Like blower-derived engines designed long periods high-speed running opposed chain-saws short bursts addition Kengines usual application requires low vibration Both design goals fit requirements perfectly significantly different respects Kioritz shares characteristic Quadra carburetors have built-in chokes Hand-choking can awkward downright dangerous un-cowled engine practically impossible inside cowl Dario Brisighella has available add-on choke Quadra probably will fit just well Kioritz relatively high fuel consumption figure suspect due noticeable amount fuel drawn out carb air intake running ram-air scoop carb should result slightly leaner mixture settings better fuel consumption Kioritz smooth cool running high quality engine Roper maximum displacement engine current test series would expect measurements maxi mum also did have maximum thrust measurements werent really able identify peak props available did have maximum weight physical dimensions didnt have maximum fuel consumption see Kioritz notes did have maximum vibration levels first time ran engine shaking much couldnt get screwdriver otherwise easily accessible mixture screws stop engine make changes low-speed mixture until got things calmed down Once mixture set properly engine warmed up smoothed out nicely Ropers vibration relatively high especially idle does detract significantly engines usefulness struck size-to-displacement ratio engine requires very little space Quadra large flywheel close behind prop does mean need fairly flat-faced cowl longer prop adapter would simplify getting engine tapering cowl carb has external pressure pick-up can rotated 180 degrees places mixture adjustments face forward would accessible cowled engine though could accessed engine running completes Part report Unfortun 102 Model Aviation .yASINII AIRSCIU lIT PRESENTS BALSA STRIPPER PRECISION STRIP WOOD TO x INS FROM BALSA SHEET ALSO FOR DRAFTING AND PHOTO MATS USES TYPE II BLADE SUPER TOOL T PRICE WINDSOR PROPELLER CO PO BOX 112 WINDSOR CA 95492 Heres equipment need give psur props toe very best balance--balance directions Carefully crafted top grade materials BUBBLE BALArtJCER accomodates 3/161/49/32 prop holes Other sizes available special order Dealers oivited $1495 Add $150 HOWARD B HUEBL DEPT 055 postage handling ft Mien add 4% sales tax No CD0s Boo 193 Route 4 Mankato Mn 56931 Big Bangers/Beckman Continued page 28 ately Part II will appear next month December written tem perature outside just over 10 degrees thats Celsius next chapter continuing story will have wait avail ability both equipment decent weather hope information presented will use will add soon possible RC Aerobatics/Van Putte Continued page 33 ing comments about flying high altitude has some interesting news us fly near sea level Randy wrote Im compelled send another side altitude story elevation 6000 ft used Lanier Sb Comets 35s Falcon 56s 19s 25s learn sans instructors five years back Theres no lack power fact Sb Comet will fly Enya 35 sleeve turned 1800 1 did flew poorly sure flying Senior Falcons Lanier Comets 40s 60s Sig Kadets 30s 35s Some 40 60 sport birds fly better 60s heavy built right fly fine 40 will admit altitude affects aircraft per formance might throw contest flier off game try play big motor altitude difference too heavy have lot guys learning fly 25 35 trainer 40 45 hot ship beginner Trims change change throttle land hot guys Florida California wher ever bring birds fly Rockies Strips scarce west side flying great Thanks inside story Randy Ron Van Putte 111 Sleepy Oaks Rd Fort Walton Beach FL 32548 RC Soaring/Pruss Continued page 37 least three British fliers still process selecting team group Austria Germany Switzer land have formed 1SF International Soaring Forum weekend before ClAM over 80 modelers above-mentioned countries met discussed design construction techniques airfoils 68-page report resulted report three-view Spartakus presented month thanks Hansruedi Schlapfer Switzerland Years ago three-task concept came scene USAs approach treat distance task involved thermal ing order get sufficient altitude turn get maximum distance during four-minute flight Most Europeans went other route began design slick machines would fly 12-lap course just virtue slippery lines Designers Spattakus boast LID nearly 20/1 ratio doesnt jostle 10-minute duration design envelope ponder standard 150-meter launch straightline distance 3000 meters Orwell over mile can flown no-wind condition Put F3B Distance-task perspective means nearly 20 laps could flown Wing construction alone could feature design article Ill pass just few points now Construction similar mentioned Continued page 104 MEW oo pR@ U3 Quadra McCulloch Super Hustler new prop hub will fit any e engines ones 5/1 6-24 shaft Bolt plate serves drill jig aod tapped spinner bolt Only $1995ROUSH MFG Dealer ributorP0 Box 251 Inquiries WelcomeSandyville Ohio 44671 C Catalog entie tine airplane Control line model lids P C scale Trainer kits boat model kits accessories etc SO enciosee Name __________________________ ______________________________ City Free-Flight fl/C Assist SUPER BRIGADIER 66 Plan SetSpanFo 15 ta 25 Pawor 2-4 channel 8/C Old favorite #RCFF 2 $995 RIC version has ailerons SUPER BRIGADIER 44 1 /2A A/C Fre-Flight AssistPlan 44 Span qor A/C Training#RC Set $ Prices tor Complete Plans Sub Assembly Detailed Parts Lists Add $200 tor Mailing Tube Send $100 retundable tor Complete Information Kits some really great things come S.: April 1981 103 STEELING MODELS BUILDING 3620 G StreetPhiladelphia Pa 19134 BASEBALL CAPSINTRODUCTORY OFFER See club emblem printed full color comfortable sport caps Order Now $500 ea Send catalog & quantity disc ______e 2021-B THIRD STREET RIVERSIDE CA 92507

b Beckman Kirby Crawford hi ban ersfo Giant Scale contributing editor teamed up another noted flier big birds give us good look four gasoline-burners being used power RC biggies Part GIANT SCALE fairly recent term used describe RC aircraft larger what has come tobe considered usual RC model big birds arent really new early days RC took good-sized plane carry radio gear needed modern lightweight equipment came along few dedicated souls stayed large format problem however finding adequate power Giant Scale movement see today didnt really get started until gasoline engines roughly 2 3 cu displacement became readily available some time people converting chain-saw other small engines driving propellers real spark Quadra already converted became available quantity point big birds became miniature aircraft just big chaperoned Free Flight models Giant Scale really took off Today fairly wide selection engines available Giant Scale builders As result newcomers field faced problem deciding power plant Bob Beckmans RC Giant Scale column receives almost daily queries about various plans kits availableand what engine use model er getting ready start new project kitbuilt plan-built scratch-built has lot questions What engine has power need Will fit space have available What mounting bolt pattern does throttle hook-up What need addition engine effort find least some answers authors embarked series engine tests evaluations idea test examine kinds things would easily under stood useful average modeler Things like rpm static thrust fuel consumption physical dimensions weight can measured reported objectively Additional factors interest and/or importance subjective nature beyond ability measure objec tively included clearly identified test procedures deliberately very sophisticated test equipment consists venerable Heathkit Thumb Tach homemade SO-lb capacity thrust measuring test stand 25lb capacity scale weight measurements stopwatch kind setup almost modeler could come up probably wouldnt just two engines expect run 15 20 engines before through current series tests will cover gasoline-burners enough interest may series larger glow engines prop drives intent make imply recom mendations against particular engines What have tried collect make available data potential users need order make informed decisions about Giant Scale power plants big bird engine know capable flying some kind Giant Scale aircraft no engine suitable design hope efforts will help April 1 981 25 opposite page Kirby Crawford taking rpm reading Bob Beckman recording data Above Bob works throttle Kirby flips prop left-handed Project requires lots paraphernalia Note use hearing protectors both Additional tests made later & dealers japan z mci mount 2a-6 prop plate ank None ad fuel mix 321 make proper selection dream bird data engine presented standard forms plus table showing rpm m PROPSDYNATHRUSTTOP FLITEZINGER KOLBOGRISH ENGINES18-6 18-8 20-820-1020-620-8 20-620-52210248 Idler RPM3ee ULIA aij Top RPM7500 7900 6900 590000 6000 72007100 Thrust nib/5 /619/6/6 17/918 Idle 20002000 900 2000 1000 2000 Ci RPM 81007100 6200 7200 600 7900 oo Thrust nib/75215QO52/S221/5 1 Idle~95ct2000200022002000 RPM 5500 Top RPM8i00750060076007000Sooo NThrust2120522522 22 lb173 Idle cRPM2Ooo200520001000100020082000 Top 75000o710070007900c0o05700 oRPM mi. Thu335225 1z525 oh data recorded authors note several seeming anomalies have no explanation present time instance note variations thrust compared rpm forthe different engines tested using Dynathrust 20-8 prop thrust tigures tor engines props involved forms should self-explanatory next few paragraphs describe procedures used Engines engines new disassembled internal pictures inspection obvious no brief check run engine set up run according instructions supplied recommended fuel mix propeller used after initial mixture adjustments tank fuel 14 oz run through 5000 rpm realize does represent com plete break-in engines time facilities available didnt allow luxury Bob Beckman plans make follow-up reports RC Giant Scale column running time experience built up engine Propellers propeller carefully bal anced Only given size make propeller used same prop run engine appropriate writing commercially-available props hand Additional test runs planned can obtained Fuel Regular leaded gasoline used cases Homelite chain-saw engine oil used engines except Kawasaki 26 Model Aviation Bel Ray MC-1 specified cases gas/oil ratio listed particular engine Starting Unless otherwise noted starting done hand wrist arm shoulder get sore found best starting procedure engines cold fully open throttle close choke choke hand no choke engine flip prop through until engine pops reset throttle point just above idle partially open choke continue flipping until engine runs choke gradually opened engine warms up warm engines usually start quickly low throttle setting little no choking Note above procedure usable engine well secured test stand Since possible engine start during choking stage procedure should used engine mounted plane Once experience gained given engine required number choking flips can done ignition off Thrust measurement know static thrust does tell whole story Things change once prop starts moving through air instead just moving air different airplanes can require different props 8 though using same engine However done reasonable care static thrust measure ments can good gauge relative performance both engines propellers Besides us game town Test sequence After initial break-in de scribed above mixture idle adjustments rechecked minimum reliable idle speed maximum high speed good transition Initially done propeller no significant difference could detected final procedure make adjustments once leave subsequent runs sequence followed 1 Measure idle rpm 2 Measure maximum rpm 3 Measure thrust maximum rpm repeated propeller available moving up down size pitch until significant decrease performance identified practical limits engine case larger engines upper limit could identified propellers available us time tests After running propeller produc ing highest thrust used fuel consumption check 1 4-oz tank topped off engine started set top speed stopwatch used time run until tank dry rpm thrust data presented doesnt always match previously-published figures isnt surprising considering variables involved However test runs reported April 1981 27 es goca view testing rig uox secured 1/2-jfl pegs driven ground performed same day using same equipment over time span about four hours during no major changes weather conditions wish thank following firms assistance project CB Associates Inc Kawasaki 21658 Cloud Way Hayward CA 94545 Dynathrust Props Inc 2541 NE 11th Court Pompano Beach FL 33062 Gibbs Hobby & Research Kioritz 6195 BA mci mount rop 161 fuel ation Hillfield St NW North Canton OH 44720 Grish Bros St John IN 46373 Homers Sales Roper 300 Dixie Hwy Beecher IL 60401 Top Flite Models Inc 1901 Narragansett Ave Chicago IL 60639 Trail Manufacturing Ltd Quadra PO Box 549 Huron Park Ont NOM LYO Canada Special Notes Subjective Data model stock flywheel minor mechani cal difficulty throttle plate prevented proper idling during tests Since did affect high-speed operation decided complete rest sequence engine could included report As chain-saw-derived engines Quadra has rear-facing exhaust rear shaft extension shaft originally drove chain Both factors can complicate mounting exhaust routing However available kits plans designed Quadra designers have solved problems consider prop hub supplied engine marginal small diameter face can crush dig prop hub several good replacements available Ron Shettler CB Associates Rual Eng others Kawasaki TA36 engine tested early model crankcase pressure pump supplied internally arrangement re quires positioning carburetor makes adjustment high- low-speed needles difficult engine running Later models TA-S 1 tested utilize external pressure tap adjustments easily accessed Continued page 102 28 Model Aviation ase nd tank Mount Iedfuel mix 161 Quadra engine tested original uaggie os big bangers waiting turns tor testing L-H hoper Kawasaki Kioritz Beckmans home-brew Homelite Quadra Latter original model since has updated twice Radio Technique/Myers Continued page 23 elevator Therefore L~ 525 J 12125 D 371/125 0 Servo torque required T CF F 5 last months chart T--- x94x94x 126x525xoooo5 867 125 In-oz Better use World Engines S-16 Norm George M Myers 70 Froehlich Farm Road Hicksville NY 11801 bulky look engine due rectangular portions crankcase casting can removed turns out weight saved less three ounces doesnt justify machining cost An unusual feature Kawasaki engines cylinder can repositioned 180 degrees normal configuration carb side exhaust other cylinder test engine rotated carb exhaust same side makes horizontal mounting snap cowl like Pitts Kawasaki high quality cool running smooth engine Kioritz engine makes best first impres sion pretty well lives up Like blower-derived engines designed long periods high-speed running opposed chain-saws short bursts addition Kengines usual application requires low vibration Both design goals fit requirements perfectly significantly different respects Kioritz shares characteristic Quadra carburetors have built-in chokes Hand-choking can awkward downright dangerous un-cowled engine practically impossible inside cowl Dario Brisighella has available add-on choke Quadra probably will fit just well Kioritz relatively high fuel consumption figure suspect due noticeable amount fuel drawn out carb air intake running ram-air scoop carb should result slightly leaner mixture settings better fuel consumption Kioritz smooth cool running high quality engine Roper maximum displacement engine current test series would expect measurements maxi mum also did have maximum thrust measurements werent really able identify peak props available did have maximum weight physical dimensions didnt have maximum fuel consumption see Kioritz notes did have maximum vibration levels first time ran engine shaking much couldnt get screwdriver otherwise easily accessible mixture screws stop engine make changes low-speed mixture until got things calmed down Once mixture set properly engine warmed up smoothed out nicely Ropers vibration relatively high especially idle does detract significantly engines usefulness struck size-to-displacement ratio engine requires very little space Quadra large flywheel close behind prop does mean need fairly flat-faced cowl longer prop adapter would simplify getting engine tapering cowl carb has external pressure pick-up can rotated 180 degrees places mixture adjustments face forward would accessible cowled engine though could accessed engine running completes Part report Unfortun 102 Model Aviation .yASINII AIRSCIU lIT PRESENTS BALSA STRIPPER PRECISION STRIP WOOD TO x INS FROM BALSA SHEET ALSO FOR DRAFTING AND PHOTO MATS USES TYPE II BLADE SUPER TOOL T PRICE WINDSOR PROPELLER CO PO BOX 112 WINDSOR CA 95492 Heres equipment need give psur props toe very best balance--balance directions Carefully crafted top grade materials BUBBLE BALArtJCER accomodates 3/161/49/32 prop holes Other sizes available special order Dealers oivited $1495 Add $150 HOWARD B HUEBL DEPT 055 postage handling ft Mien add 4% sales tax No CD0s Boo 193 Route 4 Mankato Mn 56931 Big Bangers/Beckman Continued page 28 ately Part II will appear next month December written tem perature outside just over 10 degrees thats Celsius next chapter continuing story will have wait avail ability both equipment decent weather hope information presented will use will add soon possible RC Aerobatics/Van Putte Continued page 33 ing comments about flying high altitude has some interesting news us fly near sea level Randy wrote Im compelled send another side altitude story elevation 6000 ft used Lanier Sb Comets 35s Falcon 56s 19s 25s learn sans instructors five years back Theres no lack power fact Sb Comet will fly Enya 35 sleeve turned 1800 1 did flew poorly sure flying Senior Falcons Lanier Comets 40s 60s Sig Kadets 30s 35s Some 40 60 sport birds fly better 60s heavy built right fly fine 40 will admit altitude affects aircraft per formance might throw contest flier off game try play big motor altitude difference too heavy have lot guys learning fly 25 35 trainer 40 45 hot ship beginner Trims change change throttle land hot guys Florida California wher ever bring birds fly Rockies Strips scarce west side flying great Thanks inside story Randy Ron Van Putte 111 Sleepy Oaks Rd Fort Walton Beach FL 32548 RC Soaring/Pruss Continued page 37 least three British fliers still process selecting team group Austria Germany Switzer land have formed 1SF International Soaring Forum weekend before ClAM over 80 modelers above-mentioned countries met discussed design construction techniques airfoils 68-page report resulted report three-view Spartakus presented month thanks Hansruedi Schlapfer Switzerland Years ago three-task concept came scene USAs approach treat distance task involved thermal ing order get sufficient altitude turn get maximum distance during four-minute flight Most Europeans went other route began design slick machines would fly 12-lap course just virtue slippery lines Designers Spattakus boast LID nearly 20/1 ratio doesnt jostle 10-minute duration design envelope ponder standard 150-meter launch straightline distance 3000 meters Orwell over mile can flown no-wind condition Put F3B Distance-task perspective means nearly 20 laps could flown Wing construction alone could feature design article Ill pass just few points now Construction similar mentioned Continued page 104 MEW oo pR@ U3 Quadra McCulloch Super Hustler new prop hub will fit any e engines ones 5/1 6-24 shaft Bolt plate serves drill jig aod tapped spinner bolt Only $1995ROUSH MFG Dealer ributorP0 Box 251 Inquiries WelcomeSandyville Ohio 44671 C Catalog entie tine airplane Control line model lids P C scale Trainer kits boat model kits accessories etc SO enciosee Name __________________________ ______________________________ City Free-Flight fl/C Assist SUPER BRIGADIER 66 Plan SetSpanFo 15 ta 25 Pawor 2-4 channel 8/C Old favorite #RCFF 2 $995 RIC version has ailerons SUPER BRIGADIER 44 1 /2A A/C Fre-Flight AssistPlan 44 Span qor A/C Training#RC Set $ Prices tor Complete Plans Sub Assembly Detailed Parts Lists Add $200 tor Mailing Tube Send $100 retundable tor Complete Information Kits some really great things come S.: April 1981 103 STEELING MODELS BUILDING 3620 G StreetPhiladelphia Pa 19134 BASEBALL CAPSINTRODUCTORY OFFER See club emblem printed full color comfortable sport caps Order Now $500 ea Send catalog & quantity disc ______e 2021-B THIRD STREET RIVERSIDE CA 92507