Control Line SCALE Bill Boss HAVE YOU ever wondered fine-line cracks show up finish model after few flights could aging finish bad glue joints perhaps half dozen other reasons might also because vibration improperly-mounted engine would seem certain amount vibra tion expected engines however can keep minimum little extra effort during engine mounting process two basic methods mounting engines today use pre-made mounts metal some adjustable parts molded composition plastic other good old standby hardwood Regardless method type used care must taken install mounts solidly fuselage sure engine solidly mounts case wooden mounts care must taken mating engine mounts avoid conditions such FOKker D-1 Jell Jones New Orleans LA flew other Sport Scale entires 1982 New Orleans Ringmasters annual contest capture 1st place column tells done Photo Ed Shearer shown Figures B Figure C correct mounting method engine mounted shown Figures B stress can applied engine mounting structure well engine crankcase during bolting-in process stressed crankcase can very serious source overheating vibration Vibration generated under circumstances transmitted throughout model would likely cause finish problems mentioned beginning item serious pro longed vibration problem could cause intemal structural failureand possibly loss model using ready-made mounts such shown Figure D consideration must also given correctly mounting engine mount sure follow manufacturers instructions drilling tapping required use proper size bolts nuts Another consideration type mount see has solid base mounted sure models firewall appropriate thickness engine sizeand solidly mounted fuselage properly-mounted engine will smootherrunning less prone overheating give maxi mum power output will less apt cause intemal external structural failures model Maneuvers alone can win Ed Shearer Metairie LA reports CL Scale activities Ringmasters annual two-day meet New Orleans report indicates Sport Scale Open class won Jeff Jones ofNew Orleans very unique way Jeff good Stunt flier flew Continued page 164 Dickey Bruce NewOrleans LA converted RC kitforthis Mr Mulligan flew 1980 Nats Photo Ed Shearer January 1983 67 Al Arnold New Orleans LA built 6-17 Guillow kitits powered four Cox 049s realism twofold its weathered/worn finish realistic flights Shearer photos Basics Dos Donts engine mounting Properengine mounting can improvethe perform *k iine -1 model details column Designed ZGe ~&%4A Minimaster Easytobuild.easytofly.raCY. tugged. fufl fighL U Wingspan 49W ne 15-25 Area 416 sq U Weight 3 lbs ANDREWS L AIRCRAFT MODEL COMPANY1j\ division Great Planes Model Manufacturing Company Aeromaster Trainennaster Minimaster Sportmaster Available local hobby shop executing challenge leader stayed near wall began descend came closer Twice thought touch continued flya rare feat As model settled below sloping wall Romanians gathered side hall British other Nervous comments passed between team mates model seemed slow its descent 10 feet adding anxiety Finally landed just 12 seconds short time needed win Romanians threw up great cheer Morar hoisted shoulders Pymm quietly congratulated come nowhere last two rounds capture second place ironic top three carried teammates like team place ments some statistics examined provide intersting contrast 1980 World Championships West Baden site half height salt Slanic 10% flights exceeded 30 minutes 44% below 20 minutes corresponding percentages West Baden 23 39 respectively salt hostile uninitiated veterans alike Morar two good flights win Poles perennially excel site yet could reach top 10 week before World Championship Bezman posted 37 minutes became national champion Yet unable break 32 contest Conditions certainly deteriorated primarily due great addition peopleeach body 100-watt heater changing normal equilibrium first time 12 years 4 Gal Casa %Oneor5GalCan24Gall2OGal3OGaIDrum54GaIDrum NibaGal Per GalPer GalPer Gal %10506605755351030014000 5%11507806955851520023500 10%14009108257792050033000 12%15009709008672270036800 15%160010109259002580042500 25%23001750160014473630081400 40%30002500230021005200089700 60%380033003100290070500123000 NEW Economy Fuel Castor Oil Lubricant 10% 1100 780 700 660 17000 28000 Free delivery 14 525 126 gal deals USA 30 & 54 gal drums freight collect FOB clover sc Gallon price determined nituo content & total quantity ordered sc orders add 4 % sales tax Use charge card order coDs limited UPS shipment Deduct 3% prepeymant Money Order certified check NEWPower Booster Oil ecale engines. qt $30/gelplicasweuiijsctto NEWPower Booster scale engine $12/qt. 838/gel freight included Use 3 ozJgeldung ~4lhaut rmd 803 222-7488 222-7285 World Championship held 1970 conditions worse use electrical heaters warm contes tants year cool fluorescent bulbs provided lots light little heat organizers did everything within power limit number people flying area contestants official flights team managers timers Nevertheless drift could eliminated inversion layer strong Despite problems came great surprise find collision occurred during practice organizers worked diligently toward success event listened contestants made changes sche dules Accommodations excellent right down fresh flowers room daily maid service almost too much savory Romanian food eat meet will long remembered contestant will look forward challenge salt sometime future CL Scale/Boss Continued page 67 Sterling Fokker D-7 did have throttle control other mechanical options ever six options selected flight portion event included wingover inside loop two laps inverted flight outside loop inside square loop three laps 450 elevation evidently flew well enough beat out several entries appears Jeff met challenge flying against WW II typesand won Among competition B-17 109E 51 H Mustang Another comment Ed several other Scale fliers since taking over column contest report contest manage ment did enforce Scale muffler rule action feel prompts Scale modelers compete also noted rule deterrant some areas Scale modelers competing Nats dont necessarily agree use non-use mufflers should keep anyone competing Nats can agree another Eds thoughts appears 164 Model Aviation A-Ray H-Ray Big H-Ray X-Ray place CL Scale muffler rule enforced Nats own experience East Coast contest circuit has sameno enforce ment muffler rule since its origination 1978 doesnt seem appropriate have use mufflers relatively quiet Scale models other CL models same contest flown wide-open exhausts Ed also asked what could done about revers ing rule suggested him anything done CL Scale modelers must let AMA Scale Contest Board know feel somewhere along line someone must submit rules change proposals Editors note Bill could nor have known about two rules proposals hare sub mittedforthe current cycle rules changes SC84-9 SC-84-10 propose delete re quirement mufflers CL Sport Scale CL Precision Scale respectively can read entire proposals summaries December Competition Newsletter RMcM might also appropriate write National Association Scale Aeromodelers C/O Bob Underwood 4109 Concord Oaks Dr St Louis MO 63128 enough pressure placed Scale board NASA maybe muffler rule CL Scale models can reversed last thought would like point Out writer Im sure Ed fellow modelers against use mufflers required preserve flying sites meet community noise standards makes sense we can keep aeromodeling everyones highest regard doesnt seem make sense have rule will way deter competition level noise does appear problem Perhaps solution would modify rule wording CL Scale entries meet levels Nats would need mufflers unless specified contest management meet flying site noise require ments New sanding tool Pete Bianchini Yonkers NY brought attention rather new hand-held sanding tool does great job tool made plastic has palm-size grip has built-in sandpaper supply receptacle tool made 3M Co found auto supply stores called Auto-Pak Pressn Sand sandpaper tool comes rolls vary length 55 85 depending paper gritwhich 100 180 320 usable sanding surface measures approximately 2 4 great sanding large semi-flat surfaces such wings tails Instruc tion applying sandpaper packag ing very clear easy follow Cost tool about $600 rolls ofsandpaper about $175 Bill Boss 77-06 269th St New Hyde Park NY 11040 Propellers Brownlee Con fin ued page 80 read E E scale Calculate thrust shown As pure calculations errors HP thrust will total inherent nomo graph caused deviation Cp propeller considered model used practical sense errors can shrunk substantially ac curate engine power curve used con junction calculations Continue steps 2 3 4 until propeller power curve intersects engine power curve may also use cube law after initial estimate optimum power usage intersection curves should near peak power RPM engine curve relatively flat Cp propeller measured say 10% higher model result will engine will turn about 32% slower intersection RPM will cause insignificant power loss Error calcu lated thrust value will principally error engine curve plus cube root percent deviation actual Cp model Obviously very accurate en gine curve propeller close model results will quite accurate Whether engine-propeller combination will reach HPMPH values indicated course contingent having appropriate air frame drag use nomograph power matching results will reliable variables Eq 4 accurately known MPH527 4 CD x Wing Areasq ft Pattern planes with retracts CD continued page 168 January1983 165 AC/DC AUTO CHARGER No 4005B liDS DELUXE HEAVY DUlY AC/DC AITFO CHARGER IS JUST PERFECT FOE SAFE REUABLE FAST CHARGING OF ThE NICAD DAFFERY IN YOUR PLANE BOAT OR CAR Fl HAS ALL ThESE FEATURES YOU ASKED FOR Has adjustable rate zero am amp charges 4 5 6 7 8 cells Charges 250 mahr up 18 ahr cells Works llOv house current Works 12v auto battery gel cell Has equalizer circuit pilot light Has jacks external voltmeter Use boats cars planes Use transmitter receiver Use motor break $6995 Astro flight Inc 13311 Beach Ave Vemice Cailfotnia 90291 2138216242 Solve Sanding Problems SPEED STIX Disposable Sanding Tools Inconvenient Hard-to-Sand Spotsl S Use Wet Dry @3 Sanding Grades 100 120 160 $485 Regular SPEED STIX 9 Stix 3 grade 1/4 3/8 1/2 diam $295 Mini SPEED STIX Set 6 1/8 3/16 1/4 diam 120 & 180 Orders Postpaid Order Direct Precision Sanding Tools 2930 Skyview Ave Pueblo CO 81008 Eve Phone 303 542-6200 $4995 KIT #12 51 Wingspan- 19-40 Engine Foam Wzng- Balsa Fuse Easy Picture Instructions Send Money Order- Pay UPS Ill Res add $2 00 Tax Dealer Inquiries Invited GT MODELS Pb 217-893-4136 P0 Box 869 Rantoul III 61866
Edition: Model Aviation - 1983/01
Page Numbers: 67, 164, 165
Control Line SCALE Bill Boss HAVE YOU ever wondered fine-line cracks show up finish model after few flights could aging finish bad glue joints perhaps half dozen other reasons might also because vibration improperly-mounted engine would seem certain amount vibra tion expected engines however can keep minimum little extra effort during engine mounting process two basic methods mounting engines today use pre-made mounts metal some adjustable parts molded composition plastic other good old standby hardwood Regardless method type used care must taken install mounts solidly fuselage sure engine solidly mounts case wooden mounts care must taken mating engine mounts avoid conditions such FOKker D-1 Jell Jones New Orleans LA flew other Sport Scale entires 1982 New Orleans Ringmasters annual contest capture 1st place column tells done Photo Ed Shearer shown Figures B Figure C correct mounting method engine mounted shown Figures B stress can applied engine mounting structure well engine crankcase during bolting-in process stressed crankcase can very serious source overheating vibration Vibration generated under circumstances transmitted throughout model would likely cause finish problems mentioned beginning item serious pro longed vibration problem could cause intemal structural failureand possibly loss model using ready-made mounts such shown Figure D consideration must also given correctly mounting engine mount sure follow manufacturers instructions drilling tapping required use proper size bolts nuts Another consideration type mount see has solid base mounted sure models firewall appropriate thickness engine sizeand solidly mounted fuselage properly-mounted engine will smootherrunning less prone overheating give maxi mum power output will less apt cause intemal external structural failures model Maneuvers alone can win Ed Shearer Metairie LA reports CL Scale activities Ringmasters annual two-day meet New Orleans report indicates Sport Scale Open class won Jeff Jones ofNew Orleans very unique way Jeff good Stunt flier flew Continued page 164 Dickey Bruce NewOrleans LA converted RC kitforthis Mr Mulligan flew 1980 Nats Photo Ed Shearer January 1983 67 Al Arnold New Orleans LA built 6-17 Guillow kitits powered four Cox 049s realism twofold its weathered/worn finish realistic flights Shearer photos Basics Dos Donts engine mounting Properengine mounting can improvethe perform *k iine -1 model details column Designed ZGe ~&%4A Minimaster Easytobuild.easytofly.raCY. tugged. fufl fighL U Wingspan 49W ne 15-25 Area 416 sq U Weight 3 lbs ANDREWS L AIRCRAFT MODEL COMPANY1j\ division Great Planes Model Manufacturing Company Aeromaster Trainennaster Minimaster Sportmaster Available local hobby shop executing challenge leader stayed near wall began descend came closer Twice thought touch continued flya rare feat As model settled below sloping wall Romanians gathered side hall British other Nervous comments passed between team mates model seemed slow its descent 10 feet adding anxiety Finally landed just 12 seconds short time needed win Romanians threw up great cheer Morar hoisted shoulders Pymm quietly congratulated come nowhere last two rounds capture second place ironic top three carried teammates like team place ments some statistics examined provide intersting contrast 1980 World Championships West Baden site half height salt Slanic 10% flights exceeded 30 minutes 44% below 20 minutes corresponding percentages West Baden 23 39 respectively salt hostile uninitiated veterans alike Morar two good flights win Poles perennially excel site yet could reach top 10 week before World Championship Bezman posted 37 minutes became national champion Yet unable break 32 contest Conditions certainly deteriorated primarily due great addition peopleeach body 100-watt heater changing normal equilibrium first time 12 years 4 Gal Casa %Oneor5GalCan24Gall2OGal3OGaIDrum54GaIDrum NibaGal Per GalPer GalPer Gal %10506605755351030014000 5%11507806955851520023500 10%14009108257792050033000 12%15009709008672270036800 15%160010109259002580042500 25%23001750160014473630081400 40%30002500230021005200089700 60%380033003100290070500123000 NEW Economy Fuel Castor Oil Lubricant 10% 1100 780 700 660 17000 28000 Free delivery 14 525 126 gal deals USA 30 & 54 gal drums freight collect FOB clover sc Gallon price determined nituo content & total quantity ordered sc orders add 4 % sales tax Use charge card order coDs limited UPS shipment Deduct 3% prepeymant Money Order certified check NEWPower Booster Oil ecale engines. qt $30/gelplicasweuiijsctto NEWPower Booster scale engine $12/qt. 838/gel freight included Use 3 ozJgeldung ~4lhaut rmd 803 222-7488 222-7285 World Championship held 1970 conditions worse use electrical heaters warm contes tants year cool fluorescent bulbs provided lots light little heat organizers did everything within power limit number people flying area contestants official flights team managers timers Nevertheless drift could eliminated inversion layer strong Despite problems came great surprise find collision occurred during practice organizers worked diligently toward success event listened contestants made changes sche dules Accommodations excellent right down fresh flowers room daily maid service almost too much savory Romanian food eat meet will long remembered contestant will look forward challenge salt sometime future CL Scale/Boss Continued page 67 Sterling Fokker D-7 did have throttle control other mechanical options ever six options selected flight portion event included wingover inside loop two laps inverted flight outside loop inside square loop three laps 450 elevation evidently flew well enough beat out several entries appears Jeff met challenge flying against WW II typesand won Among competition B-17 109E 51 H Mustang Another comment Ed several other Scale fliers since taking over column contest report contest manage ment did enforce Scale muffler rule action feel prompts Scale modelers compete also noted rule deterrant some areas Scale modelers competing Nats dont necessarily agree use non-use mufflers should keep anyone competing Nats can agree another Eds thoughts appears 164 Model Aviation A-Ray H-Ray Big H-Ray X-Ray place CL Scale muffler rule enforced Nats own experience East Coast contest circuit has sameno enforce ment muffler rule since its origination 1978 doesnt seem appropriate have use mufflers relatively quiet Scale models other CL models same contest flown wide-open exhausts Ed also asked what could done about revers ing rule suggested him anything done CL Scale modelers must let AMA Scale Contest Board know feel somewhere along line someone must submit rules change proposals Editors note Bill could nor have known about two rules proposals hare sub mittedforthe current cycle rules changes SC84-9 SC-84-10 propose delete re quirement mufflers CL Sport Scale CL Precision Scale respectively can read entire proposals summaries December Competition Newsletter RMcM might also appropriate write National Association Scale Aeromodelers C/O Bob Underwood 4109 Concord Oaks Dr St Louis MO 63128 enough pressure placed Scale board NASA maybe muffler rule CL Scale models can reversed last thought would like point Out writer Im sure Ed fellow modelers against use mufflers required preserve flying sites meet community noise standards makes sense we can keep aeromodeling everyones highest regard doesnt seem make sense have rule will way deter competition level noise does appear problem Perhaps solution would modify rule wording CL Scale entries meet levels Nats would need mufflers unless specified contest management meet flying site noise require ments New sanding tool Pete Bianchini Yonkers NY brought attention rather new hand-held sanding tool does great job tool made plastic has palm-size grip has built-in sandpaper supply receptacle tool made 3M Co found auto supply stores called Auto-Pak Pressn Sand sandpaper tool comes rolls vary length 55 85 depending paper gritwhich 100 180 320 usable sanding surface measures approximately 2 4 great sanding large semi-flat surfaces such wings tails Instruc tion applying sandpaper packag ing very clear easy follow Cost tool about $600 rolls ofsandpaper about $175 Bill Boss 77-06 269th St New Hyde Park NY 11040 Propellers Brownlee Con fin ued page 80 read E E scale Calculate thrust shown As pure calculations errors HP thrust will total inherent nomo graph caused deviation Cp propeller considered model used practical sense errors can shrunk substantially ac curate engine power curve used con junction calculations Continue steps 2 3 4 until propeller power curve intersects engine power curve may also use cube law after initial estimate optimum power usage intersection curves should near peak power RPM engine curve relatively flat Cp propeller measured say 10% higher model result will engine will turn about 32% slower intersection RPM will cause insignificant power loss Error calcu lated thrust value will principally error engine curve plus cube root percent deviation actual Cp model Obviously very accurate en gine curve propeller close model results will quite accurate Whether engine-propeller combination will reach HPMPH values indicated course contingent having appropriate air frame drag use nomograph power matching results will reliable variables Eq 4 accurately known MPH527 4 CD x Wing Areasq ft Pattern planes with retracts CD continued page 168 January1983 165 AC/DC AUTO CHARGER No 4005B liDS DELUXE HEAVY DUlY AC/DC AITFO CHARGER IS JUST PERFECT FOE SAFE REUABLE FAST CHARGING OF ThE NICAD DAFFERY IN YOUR PLANE BOAT OR CAR Fl HAS ALL ThESE FEATURES YOU ASKED FOR Has adjustable rate zero am amp charges 4 5 6 7 8 cells Charges 250 mahr up 18 ahr cells Works llOv house current Works 12v auto battery gel cell Has equalizer circuit pilot light Has jacks external voltmeter Use boats cars planes Use transmitter receiver Use motor break $6995 Astro flight Inc 13311 Beach Ave Vemice Cailfotnia 90291 2138216242 Solve Sanding Problems SPEED STIX Disposable Sanding Tools Inconvenient Hard-to-Sand Spotsl S Use Wet Dry @3 Sanding Grades 100 120 160 $485 Regular SPEED STIX 9 Stix 3 grade 1/4 3/8 1/2 diam $295 Mini SPEED STIX Set 6 1/8 3/16 1/4 diam 120 & 180 Orders Postpaid Order Direct Precision Sanding Tools 2930 Skyview Ave Pueblo CO 81008 Eve Phone 303 542-6200 $4995 KIT #12 51 Wingspan- 19-40 Engine Foam Wzng- Balsa Fuse Easy Picture Instructions Send Money Order- Pay UPS Ill Res add $2 00 Tax Dealer Inquiries Invited GT MODELS Pb 217-893-4136 P0 Box 869 Rantoul III 61866
Edition: Model Aviation - 1983/01
Page Numbers: 67, 164, 165
Control Line SCALE Bill Boss HAVE YOU ever wondered fine-line cracks show up finish model after few flights could aging finish bad glue joints perhaps half dozen other reasons might also because vibration improperly-mounted engine would seem certain amount vibra tion expected engines however can keep minimum little extra effort during engine mounting process two basic methods mounting engines today use pre-made mounts metal some adjustable parts molded composition plastic other good old standby hardwood Regardless method type used care must taken install mounts solidly fuselage sure engine solidly mounts case wooden mounts care must taken mating engine mounts avoid conditions such FOKker D-1 Jell Jones New Orleans LA flew other Sport Scale entires 1982 New Orleans Ringmasters annual contest capture 1st place column tells done Photo Ed Shearer shown Figures B Figure C correct mounting method engine mounted shown Figures B stress can applied engine mounting structure well engine crankcase during bolting-in process stressed crankcase can very serious source overheating vibration Vibration generated under circumstances transmitted throughout model would likely cause finish problems mentioned beginning item serious pro longed vibration problem could cause intemal structural failureand possibly loss model using ready-made mounts such shown Figure D consideration must also given correctly mounting engine mount sure follow manufacturers instructions drilling tapping required use proper size bolts nuts Another consideration type mount see has solid base mounted sure models firewall appropriate thickness engine sizeand solidly mounted fuselage properly-mounted engine will smootherrunning less prone overheating give maxi mum power output will less apt cause intemal external structural failures model Maneuvers alone can win Ed Shearer Metairie LA reports CL Scale activities Ringmasters annual two-day meet New Orleans report indicates Sport Scale Open class won Jeff Jones ofNew Orleans very unique way Jeff good Stunt flier flew Continued page 164 Dickey Bruce NewOrleans LA converted RC kitforthis Mr Mulligan flew 1980 Nats Photo Ed Shearer January 1983 67 Al Arnold New Orleans LA built 6-17 Guillow kitits powered four Cox 049s realism twofold its weathered/worn finish realistic flights Shearer photos Basics Dos Donts engine mounting Properengine mounting can improvethe perform *k iine -1 model details column Designed ZGe ~&%4A Minimaster Easytobuild.easytofly.raCY. tugged. fufl fighL U Wingspan 49W ne 15-25 Area 416 sq U Weight 3 lbs ANDREWS L AIRCRAFT MODEL COMPANY1j\ division Great Planes Model Manufacturing Company Aeromaster Trainennaster Minimaster Sportmaster Available local hobby shop executing challenge leader stayed near wall began descend came closer Twice thought touch continued flya rare feat As model settled below sloping wall Romanians gathered side hall British other Nervous comments passed between team mates model seemed slow its descent 10 feet adding anxiety Finally landed just 12 seconds short time needed win Romanians threw up great cheer Morar hoisted shoulders Pymm quietly congratulated come nowhere last two rounds capture second place ironic top three carried teammates like team place ments some statistics examined provide intersting contrast 1980 World Championships West Baden site half height salt Slanic 10% flights exceeded 30 minutes 44% below 20 minutes corresponding percentages West Baden 23 39 respectively salt hostile uninitiated veterans alike Morar two good flights win Poles perennially excel site yet could reach top 10 week before World Championship Bezman posted 37 minutes became national champion Yet unable break 32 contest Conditions certainly deteriorated primarily due great addition peopleeach body 100-watt heater changing normal equilibrium first time 12 years 4 Gal Casa %Oneor5GalCan24Gall2OGal3OGaIDrum54GaIDrum NibaGal Per GalPer GalPer Gal %10506605755351030014000 5%11507806955851520023500 10%14009108257792050033000 12%15009709008672270036800 15%160010109259002580042500 25%23001750160014473630081400 40%30002500230021005200089700 60%380033003100290070500123000 NEW Economy Fuel Castor Oil Lubricant 10% 1100 780 700 660 17000 28000 Free delivery 14 525 126 gal deals USA 30 & 54 gal drums freight collect FOB clover sc Gallon price determined nituo content & total quantity ordered sc orders add 4 % sales tax Use charge card order coDs limited UPS shipment Deduct 3% prepeymant Money Order certified check NEWPower Booster Oil ecale engines. qt $30/gelplicasweuiijsctto NEWPower Booster scale engine $12/qt. 838/gel freight included Use 3 ozJgeldung ~4lhaut rmd 803 222-7488 222-7285 World Championship held 1970 conditions worse use electrical heaters warm contes tants year cool fluorescent bulbs provided lots light little heat organizers did everything within power limit number people flying area contestants official flights team managers timers Nevertheless drift could eliminated inversion layer strong Despite problems came great surprise find collision occurred during practice organizers worked diligently toward success event listened contestants made changes sche dules Accommodations excellent right down fresh flowers room daily maid service almost too much savory Romanian food eat meet will long remembered contestant will look forward challenge salt sometime future CL Scale/Boss Continued page 67 Sterling Fokker D-7 did have throttle control other mechanical options ever six options selected flight portion event included wingover inside loop two laps inverted flight outside loop inside square loop three laps 450 elevation evidently flew well enough beat out several entries appears Jeff met challenge flying against WW II typesand won Among competition B-17 109E 51 H Mustang Another comment Ed several other Scale fliers since taking over column contest report contest manage ment did enforce Scale muffler rule action feel prompts Scale modelers compete also noted rule deterrant some areas Scale modelers competing Nats dont necessarily agree use non-use mufflers should keep anyone competing Nats can agree another Eds thoughts appears 164 Model Aviation A-Ray H-Ray Big H-Ray X-Ray place CL Scale muffler rule enforced Nats own experience East Coast contest circuit has sameno enforce ment muffler rule since its origination 1978 doesnt seem appropriate have use mufflers relatively quiet Scale models other CL models same contest flown wide-open exhausts Ed also asked what could done about revers ing rule suggested him anything done CL Scale modelers must let AMA Scale Contest Board know feel somewhere along line someone must submit rules change proposals Editors note Bill could nor have known about two rules proposals hare sub mittedforthe current cycle rules changes SC84-9 SC-84-10 propose delete re quirement mufflers CL Sport Scale CL Precision Scale respectively can read entire proposals summaries December Competition Newsletter RMcM might also appropriate write National Association Scale Aeromodelers C/O Bob Underwood 4109 Concord Oaks Dr St Louis MO 63128 enough pressure placed Scale board NASA maybe muffler rule CL Scale models can reversed last thought would like point Out writer Im sure Ed fellow modelers against use mufflers required preserve flying sites meet community noise standards makes sense we can keep aeromodeling everyones highest regard doesnt seem make sense have rule will way deter competition level noise does appear problem Perhaps solution would modify rule wording CL Scale entries meet levels Nats would need mufflers unless specified contest management meet flying site noise require ments New sanding tool Pete Bianchini Yonkers NY brought attention rather new hand-held sanding tool does great job tool made plastic has palm-size grip has built-in sandpaper supply receptacle tool made 3M Co found auto supply stores called Auto-Pak Pressn Sand sandpaper tool comes rolls vary length 55 85 depending paper gritwhich 100 180 320 usable sanding surface measures approximately 2 4 great sanding large semi-flat surfaces such wings tails Instruc tion applying sandpaper packag ing very clear easy follow Cost tool about $600 rolls ofsandpaper about $175 Bill Boss 77-06 269th St New Hyde Park NY 11040 Propellers Brownlee Con fin ued page 80 read E E scale Calculate thrust shown As pure calculations errors HP thrust will total inherent nomo graph caused deviation Cp propeller considered model used practical sense errors can shrunk substantially ac curate engine power curve used con junction calculations Continue steps 2 3 4 until propeller power curve intersects engine power curve may also use cube law after initial estimate optimum power usage intersection curves should near peak power RPM engine curve relatively flat Cp propeller measured say 10% higher model result will engine will turn about 32% slower intersection RPM will cause insignificant power loss Error calcu lated thrust value will principally error engine curve plus cube root percent deviation actual Cp model Obviously very accurate en gine curve propeller close model results will quite accurate Whether engine-propeller combination will reach HPMPH values indicated course contingent having appropriate air frame drag use nomograph power matching results will reliable variables Eq 4 accurately known MPH527 4 CD x Wing Areasq ft Pattern planes with retracts CD continued page 168 January1983 165 AC/DC AUTO CHARGER No 4005B liDS DELUXE HEAVY DUlY AC/DC AITFO CHARGER IS JUST PERFECT FOE SAFE REUABLE FAST CHARGING OF ThE NICAD DAFFERY IN YOUR PLANE BOAT OR CAR Fl HAS ALL ThESE FEATURES YOU ASKED FOR Has adjustable rate zero am amp charges 4 5 6 7 8 cells Charges 250 mahr up 18 ahr cells Works llOv house current Works 12v auto battery gel cell Has equalizer circuit pilot light Has jacks external voltmeter Use boats cars planes Use transmitter receiver Use motor break $6995 Astro flight Inc 13311 Beach Ave Vemice Cailfotnia 90291 2138216242 Solve Sanding Problems SPEED STIX Disposable Sanding Tools Inconvenient Hard-to-Sand Spotsl S Use Wet Dry @3 Sanding Grades 100 120 160 $485 Regular SPEED STIX 9 Stix 3 grade 1/4 3/8 1/2 diam $295 Mini SPEED STIX Set 6 1/8 3/16 1/4 diam 120 & 180 Orders Postpaid Order Direct Precision Sanding Tools 2930 Skyview Ave Pueblo CO 81008 Eve Phone 303 542-6200 $4995 KIT #12 51 Wingspan- 19-40 Engine Foam Wzng- Balsa Fuse Easy Picture Instructions Send Money Order- Pay UPS Ill Res add $2 00 Tax Dealer Inquiries Invited GT MODELS Pb 217-893-4136 P0 Box 869 Rantoul III 61866