Radio Control SporVAerobatics Ron Van Putte ONCE IN WHILE mentally gripe about various frustrating things involving hobby Sometimes turns vocal complaining during discussion other RC modelers Usually gripes concern individual products certain manufac turers sometimes whole RC indus try catches some flak Often complaint starts out come dont Let try few see dont agree Perhaps RCIA Radio Control Industry Asso ciation might something about particular beef response strong enough Have ever wanted plug manu facturers servo anothers radio sys tem discover plugs different changed plug match system discovered receiver put out negative-going pulse servo required opposite vice versa come dont standard ize connectors pulse requirements Has beginner ever showed up club flying site wanting get some flight training no transmitter capable being used trainer system beginners learning fly easier ever before using trainer system lot better instructor student dont have worry about juggling transmitter between trainer system requires two transmitters same manufacturer Kraft Pro-Line nobody else makes trainer system avail able far know dont manufacturers make trainer system available dont make electronically mechanically compatible another contest last summer servos started go bad fortunately able land airplane safely Since two spare servos always field box simple task replace faulty tried put arm new servo wouldnt fit though servo apparently identical old manufacturer made production change increased size output shaft new servos brought home familiar complaint RC fliers dont servos manufacturers have same size out put shaft youve purchased new radio different manufacturer havent always redo radio installation because servos didnt fit dont small medium large servos have same mounting hole pattern correspond ing size would naive part understand some suggestions Ive brought out havent imple mented before Radio system manufac turers business sell radio equip ment lot suggestions would enable RC purchasers use equip ment purchased other manufacturers radios However sev eral factors should considered favor such situation first place other manufacturer would cases resulting purchases would tend out long run One-to-one compatibility manufacturers equipment others would result better equipment because competition Lastly good will generated such move would felt years item request informa tion complaint since profes sion aeronautical engineering Frank Prestwood proudly poses semiscale Fokker D-7 uses OS Max 60 Goldhead Radio built Jim Kirkland knowledge electronics very limited During long drives contests friend Dick McGraw have talked about ways prevent shoot-downs caused having transmitter turned another flier already using frequency wondered aloud elec tronically possible financially practical fabricate frequency control device would integral part transmitter Such device would sense radiation transmitter same frequency permit offend ing transmitter turned would have activated transmitter switch would time What about electronic-types out therecontinued page 85 March1976 17 Left USAF Colonel Gene Bures Bucker Jung meister built Andraws Aeromaster kit Below Ron Britzke preps WOG 1944 FF Bill Winter Ace propo Cox TD 09 gross 28 oz Has near vertical climb excellent glide RC Sport/Van Putte continued naae 17 Last month showed some diagrams what airplane would pilot attempting perform ioop wind holding constant elevator dia grams should have left no doubt side loops Immelman turns should started upwind heading because less elevator correction required order achieve round loop same dia grams could used show outside loops AMA outside loops FAT ones should started downwind heading What left shown required control inputs vary wind speed varies Lets examine 132 ft/sec 90 mph airplane performing 100-ft radius loops keep examination within bounds 00 900 1800 2700 points ioops shown Fig 1 will docu mented should adequate suit purposes wind speeds 0 10 20 30 ft/sec Table 1 shows normalized elevator required various points loop varying wind conditions normalized eleva tor amount elevator deflection required loop divided amount elevator deflection required loop divided amount elevator required loop divided amount elevator required bottom loop no-wind situation present way because elevator ef fectiveness varies dramatically air plane airplane Note negative wind speed headwind positive wind speed corresponds tailwind Wind Speed 30 20 10 Table 1 00900 6074 7274 8575 0180 1011689 2013291 30151107 180 70 31 03 31 55 75 91 2790 63 61 61 64 63 68 83 Lets follow airplane around 1oop get picture Suppose no wind 100 up elevator required -I SPACE-AGE MODEL POWER Aircraft Helicopters Cars Speed Boats Ships Etc ROCKET HT 50 $179 space ships missiles Engine thrust 4 ozs Duration 45 secs Wgt 3/8 oz Lgt 1-3/4 Dia 7/8 FuelforEN22OPackFU2$198 Fuel EN3 150-8 FU3189 Fuel EN3 158-16 FU3A239 WICKS69 Jetex Engine Book 50 pgs100 BLUEBOOK OF HOBBIES CATALOG 160 TABLOID-SIZE PAGES $395 DEALERS/WHOLESALERS WRITE POIKS 346 BERGEN AVE JERSEY CITY NJ 07304 POLKS HOBBIES 314 Fifth Ave NY NY 10001 DeptMv March1976 85 MUFFIAl RE EXTREMELY COMPACT FULLY ADJUSTABLE NOISE LEVEL AND BACK PRESSURE FOR BETTER PERFORMANCE ADAPTS TO ALL ENGINES FROM 29 TO 60 QUIETER THAN OTHER TYPES OF MUFFLERS UNIVERSAL MUFFLER Designed installation wide variety engines MU-795universal ultimate looks $795 performance MU-795 f No143 ALSO MADE ESPECIALLY FOR OWNERS OF SUPER TIGRE 60 BLUE HEAD ENGINES MU-795ST Fastener Kit ideal way install Du-Bro Universal Mufflaire lete instructions MU-795STNo145 $100 WEBRA 60 R/C ENGINE perfect combination Webra Easiest install MW-750 attaches two hardened steel socket head screws directly thru engine lugs MW-750 No142 $795 0VEL 4 O MINI-MUFFLAIRE engines 09 25MM-595No144 $595 PRODUCTS INCORPORATED'" 480 Bonner Road Wauconda Illinois 60084 USA fidti/iu%fr P 0 D U CT S N C SVILLE ROAD OW GROVE PA 19090 659-3900 NEW. YOULL GET QUITE CHARGE OUT OF THESE Introducing llivans Pylon Brand 12-volt Gel/Cell battery ttery chargertwo great new products flight box See now dealers Gel/Cell Battery Charger Completely dry can never spill leak Never worry about filling water again Lasts full 45 amp hours between recharges Can recharged 1000 times UL listed plugs ordinary house current Fully charges battery 12 hours 500 ma output ideal new battery Can used wet cell batteriestoo start loop airplane going vertically upward 80 up elevator required top loop 310 down elevator necessary air plane going vertically downward 640 up elevator required bottom loop original 100 up elevator will start airplane second loop Compare previous control inputs required perform same size loops 30 ft/sec head wind elevator inputs same points loop 600 740 700 630 600 small elevator input changes required make much easier perfect ioop comparison take look control inputs required perfect loop 30 ft/sec tailwind would take world champion able coordinate substantial control input changes necessary airplane speed loop size wind speed combination results mintmum required control input variation dont really have option make loops too large too small compared what judges looking ever worth investigating charac teristics airplane because opti mum condition may near what judges want can paint three concentric perfectly circular loops sky judges may overlook minor size discrepancy FNWSAER U obby cente oc Last month commented character Class pattern competi tion changed substantially original intent Due difficulty graduating B pattern quality flying proficiency Class has im proved point beginner faces staggering task competing apparently unbeatable group fliers class reaction clubs situation has avoid conflict between truly novice A-pattern fliers good great A-pattern com petitors offering different forms competition common variation standard contest offer Novice Ad vanced Expert categories Class way deciding competes seems vary around country flier competes other fliers nearly same ability has chance win thing dont understand ad vancement points awarded Can clarify situation Another contest variation called Continental Pattern brainchild Canadian Percy Grondin AMA District IX Vice President Jim Mowrey flier makes up own pattern list maneuvers Up 12 maneuvers may chosen list pat tern must include take-off landing perfec tion spot landing maneuver has its own K factor measure difficulty multiplied times score earned maneuver lowest total score flights subtracted high est total score difference divided number categories competi tion resulting number added pro gressively lowest score obtain point spread category Lets try example three categories lowest score 1000 highest 4000 difference 3000 1/3 1000 So categories would 1000-2000 points 2000-3000 points 3000-4000 points Continental Pattern generally al lows fliers nearly same ability compete another equal chance win particular category Un fortunately flier has equal chance lose since few extra points may pro mote flier top category bottom another Nevertheless refreshing approach revitalizing pattern competition Next month plan discuss tech niques determining proper center mass new creation call ing local expert address 12 Connie Dr Shah mar Fla 32579 RC Helicopters continued frnm naoe 19 crash machine right now small washer between collars nylon will provide bearing surface pre vent heat build-up Lubricate tail-rotor bearings flight Yes said flight tail-rotor belt should adjusted just wont slip Check holding main rotor tail rotor Only tighten just wont slip under moderate pres sure probably will find tail boom sandwiched between holding bolts wont easily adjust can improved slotting lower-bolt holes slightly loosened boom slides easily hope article will increase flying pleasure Heli-Baby have developed some hardened tail86 Model Aviation e port continued
Edition: Model Aviation - 1976/03
Page Numbers: 17, 85, 86
Radio Control SporVAerobatics Ron Van Putte ONCE IN WHILE mentally gripe about various frustrating things involving hobby Sometimes turns vocal complaining during discussion other RC modelers Usually gripes concern individual products certain manufac turers sometimes whole RC indus try catches some flak Often complaint starts out come dont Let try few see dont agree Perhaps RCIA Radio Control Industry Asso ciation might something about particular beef response strong enough Have ever wanted plug manu facturers servo anothers radio sys tem discover plugs different changed plug match system discovered receiver put out negative-going pulse servo required opposite vice versa come dont standard ize connectors pulse requirements Has beginner ever showed up club flying site wanting get some flight training no transmitter capable being used trainer system beginners learning fly easier ever before using trainer system lot better instructor student dont have worry about juggling transmitter between trainer system requires two transmitters same manufacturer Kraft Pro-Line nobody else makes trainer system avail able far know dont manufacturers make trainer system available dont make electronically mechanically compatible another contest last summer servos started go bad fortunately able land airplane safely Since two spare servos always field box simple task replace faulty tried put arm new servo wouldnt fit though servo apparently identical old manufacturer made production change increased size output shaft new servos brought home familiar complaint RC fliers dont servos manufacturers have same size out put shaft youve purchased new radio different manufacturer havent always redo radio installation because servos didnt fit dont small medium large servos have same mounting hole pattern correspond ing size would naive part understand some suggestions Ive brought out havent imple mented before Radio system manufac turers business sell radio equip ment lot suggestions would enable RC purchasers use equip ment purchased other manufacturers radios However sev eral factors should considered favor such situation first place other manufacturer would cases resulting purchases would tend out long run One-to-one compatibility manufacturers equipment others would result better equipment because competition Lastly good will generated such move would felt years item request informa tion complaint since profes sion aeronautical engineering Frank Prestwood proudly poses semiscale Fokker D-7 uses OS Max 60 Goldhead Radio built Jim Kirkland knowledge electronics very limited During long drives contests friend Dick McGraw have talked about ways prevent shoot-downs caused having transmitter turned another flier already using frequency wondered aloud elec tronically possible financially practical fabricate frequency control device would integral part transmitter Such device would sense radiation transmitter same frequency permit offend ing transmitter turned would have activated transmitter switch would time What about electronic-types out therecontinued page 85 March1976 17 Left USAF Colonel Gene Bures Bucker Jung meister built Andraws Aeromaster kit Below Ron Britzke preps WOG 1944 FF Bill Winter Ace propo Cox TD 09 gross 28 oz Has near vertical climb excellent glide RC Sport/Van Putte continued naae 17 Last month showed some diagrams what airplane would pilot attempting perform ioop wind holding constant elevator dia grams should have left no doubt side loops Immelman turns should started upwind heading because less elevator correction required order achieve round loop same dia grams could used show outside loops AMA outside loops FAT ones should started downwind heading What left shown required control inputs vary wind speed varies Lets examine 132 ft/sec 90 mph airplane performing 100-ft radius loops keep examination within bounds 00 900 1800 2700 points ioops shown Fig 1 will docu mented should adequate suit purposes wind speeds 0 10 20 30 ft/sec Table 1 shows normalized elevator required various points loop varying wind conditions normalized eleva tor amount elevator deflection required loop divided amount elevator deflection required loop divided amount elevator required loop divided amount elevator required bottom loop no-wind situation present way because elevator ef fectiveness varies dramatically air plane airplane Note negative wind speed headwind positive wind speed corresponds tailwind Wind Speed 30 20 10 Table 1 00900 6074 7274 8575 0180 1011689 2013291 30151107 180 70 31 03 31 55 75 91 2790 63 61 61 64 63 68 83 Lets follow airplane around 1oop get picture Suppose no wind 100 up elevator required -I SPACE-AGE MODEL POWER Aircraft Helicopters Cars Speed Boats Ships Etc ROCKET HT 50 $179 space ships missiles Engine thrust 4 ozs Duration 45 secs Wgt 3/8 oz Lgt 1-3/4 Dia 7/8 FuelforEN22OPackFU2$198 Fuel EN3 150-8 FU3189 Fuel EN3 158-16 FU3A239 WICKS69 Jetex Engine Book 50 pgs100 BLUEBOOK OF HOBBIES CATALOG 160 TABLOID-SIZE PAGES $395 DEALERS/WHOLESALERS WRITE POIKS 346 BERGEN AVE JERSEY CITY NJ 07304 POLKS HOBBIES 314 Fifth Ave NY NY 10001 DeptMv March1976 85 MUFFIAl RE EXTREMELY COMPACT FULLY ADJUSTABLE NOISE LEVEL AND BACK PRESSURE FOR BETTER PERFORMANCE ADAPTS TO ALL ENGINES FROM 29 TO 60 QUIETER THAN OTHER TYPES OF MUFFLERS UNIVERSAL MUFFLER Designed installation wide variety engines MU-795universal ultimate looks $795 performance MU-795 f No143 ALSO MADE ESPECIALLY FOR OWNERS OF SUPER TIGRE 60 BLUE HEAD ENGINES MU-795ST Fastener Kit ideal way install Du-Bro Universal Mufflaire lete instructions MU-795STNo145 $100 WEBRA 60 R/C ENGINE perfect combination Webra Easiest install MW-750 attaches two hardened steel socket head screws directly thru engine lugs MW-750 No142 $795 0VEL 4 O MINI-MUFFLAIRE engines 09 25MM-595No144 $595 PRODUCTS INCORPORATED'" 480 Bonner Road Wauconda Illinois 60084 USA fidti/iu%fr P 0 D U CT S N C SVILLE ROAD OW GROVE PA 19090 659-3900 NEW. YOULL GET QUITE CHARGE OUT OF THESE Introducing llivans Pylon Brand 12-volt Gel/Cell battery ttery chargertwo great new products flight box See now dealers Gel/Cell Battery Charger Completely dry can never spill leak Never worry about filling water again Lasts full 45 amp hours between recharges Can recharged 1000 times UL listed plugs ordinary house current Fully charges battery 12 hours 500 ma output ideal new battery Can used wet cell batteriestoo start loop airplane going vertically upward 80 up elevator required top loop 310 down elevator necessary air plane going vertically downward 640 up elevator required bottom loop original 100 up elevator will start airplane second loop Compare previous control inputs required perform same size loops 30 ft/sec head wind elevator inputs same points loop 600 740 700 630 600 small elevator input changes required make much easier perfect ioop comparison take look control inputs required perfect loop 30 ft/sec tailwind would take world champion able coordinate substantial control input changes necessary airplane speed loop size wind speed combination results mintmum required control input variation dont really have option make loops too large too small compared what judges looking ever worth investigating charac teristics airplane because opti mum condition may near what judges want can paint three concentric perfectly circular loops sky judges may overlook minor size discrepancy FNWSAER U obby cente oc Last month commented character Class pattern competi tion changed substantially original intent Due difficulty graduating B pattern quality flying proficiency Class has im proved point beginner faces staggering task competing apparently unbeatable group fliers class reaction clubs situation has avoid conflict between truly novice A-pattern fliers good great A-pattern com petitors offering different forms competition common variation standard contest offer Novice Ad vanced Expert categories Class way deciding competes seems vary around country flier competes other fliers nearly same ability has chance win thing dont understand ad vancement points awarded Can clarify situation Another contest variation called Continental Pattern brainchild Canadian Percy Grondin AMA District IX Vice President Jim Mowrey flier makes up own pattern list maneuvers Up 12 maneuvers may chosen list pat tern must include take-off landing perfec tion spot landing maneuver has its own K factor measure difficulty multiplied times score earned maneuver lowest total score flights subtracted high est total score difference divided number categories competi tion resulting number added pro gressively lowest score obtain point spread category Lets try example three categories lowest score 1000 highest 4000 difference 3000 1/3 1000 So categories would 1000-2000 points 2000-3000 points 3000-4000 points Continental Pattern generally al lows fliers nearly same ability compete another equal chance win particular category Un fortunately flier has equal chance lose since few extra points may pro mote flier top category bottom another Nevertheless refreshing approach revitalizing pattern competition Next month plan discuss tech niques determining proper center mass new creation call ing local expert address 12 Connie Dr Shah mar Fla 32579 RC Helicopters continued frnm naoe 19 crash machine right now small washer between collars nylon will provide bearing surface pre vent heat build-up Lubricate tail-rotor bearings flight Yes said flight tail-rotor belt should adjusted just wont slip Check holding main rotor tail rotor Only tighten just wont slip under moderate pres sure probably will find tail boom sandwiched between holding bolts wont easily adjust can improved slotting lower-bolt holes slightly loosened boom slides easily hope article will increase flying pleasure Heli-Baby have developed some hardened tail86 Model Aviation e port continued
Edition: Model Aviation - 1976/03
Page Numbers: 17, 85, 86
Radio Control SporVAerobatics Ron Van Putte ONCE IN WHILE mentally gripe about various frustrating things involving hobby Sometimes turns vocal complaining during discussion other RC modelers Usually gripes concern individual products certain manufac turers sometimes whole RC indus try catches some flak Often complaint starts out come dont Let try few see dont agree Perhaps RCIA Radio Control Industry Asso ciation might something about particular beef response strong enough Have ever wanted plug manu facturers servo anothers radio sys tem discover plugs different changed plug match system discovered receiver put out negative-going pulse servo required opposite vice versa come dont standard ize connectors pulse requirements Has beginner ever showed up club flying site wanting get some flight training no transmitter capable being used trainer system beginners learning fly easier ever before using trainer system lot better instructor student dont have worry about juggling transmitter between trainer system requires two transmitters same manufacturer Kraft Pro-Line nobody else makes trainer system avail able far know dont manufacturers make trainer system available dont make electronically mechanically compatible another contest last summer servos started go bad fortunately able land airplane safely Since two spare servos always field box simple task replace faulty tried put arm new servo wouldnt fit though servo apparently identical old manufacturer made production change increased size output shaft new servos brought home familiar complaint RC fliers dont servos manufacturers have same size out put shaft youve purchased new radio different manufacturer havent always redo radio installation because servos didnt fit dont small medium large servos have same mounting hole pattern correspond ing size would naive part understand some suggestions Ive brought out havent imple mented before Radio system manufac turers business sell radio equip ment lot suggestions would enable RC purchasers use equip ment purchased other manufacturers radios However sev eral factors should considered favor such situation first place other manufacturer would cases resulting purchases would tend out long run One-to-one compatibility manufacturers equipment others would result better equipment because competition Lastly good will generated such move would felt years item request informa tion complaint since profes sion aeronautical engineering Frank Prestwood proudly poses semiscale Fokker D-7 uses OS Max 60 Goldhead Radio built Jim Kirkland knowledge electronics very limited During long drives contests friend Dick McGraw have talked about ways prevent shoot-downs caused having transmitter turned another flier already using frequency wondered aloud elec tronically possible financially practical fabricate frequency control device would integral part transmitter Such device would sense radiation transmitter same frequency permit offend ing transmitter turned would have activated transmitter switch would time What about electronic-types out therecontinued page 85 March1976 17 Left USAF Colonel Gene Bures Bucker Jung meister built Andraws Aeromaster kit Below Ron Britzke preps WOG 1944 FF Bill Winter Ace propo Cox TD 09 gross 28 oz Has near vertical climb excellent glide RC Sport/Van Putte continued naae 17 Last month showed some diagrams what airplane would pilot attempting perform ioop wind holding constant elevator dia grams should have left no doubt side loops Immelman turns should started upwind heading because less elevator correction required order achieve round loop same dia grams could used show outside loops AMA outside loops FAT ones should started downwind heading What left shown required control inputs vary wind speed varies Lets examine 132 ft/sec 90 mph airplane performing 100-ft radius loops keep examination within bounds 00 900 1800 2700 points ioops shown Fig 1 will docu mented should adequate suit purposes wind speeds 0 10 20 30 ft/sec Table 1 shows normalized elevator required various points loop varying wind conditions normalized eleva tor amount elevator deflection required loop divided amount elevator deflection required loop divided amount elevator required loop divided amount elevator required bottom loop no-wind situation present way because elevator ef fectiveness varies dramatically air plane airplane Note negative wind speed headwind positive wind speed corresponds tailwind Wind Speed 30 20 10 Table 1 00900 6074 7274 8575 0180 1011689 2013291 30151107 180 70 31 03 31 55 75 91 2790 63 61 61 64 63 68 83 Lets follow airplane around 1oop get picture Suppose no wind 100 up elevator required -I SPACE-AGE MODEL POWER Aircraft Helicopters Cars Speed Boats Ships Etc ROCKET HT 50 $179 space ships missiles Engine thrust 4 ozs Duration 45 secs Wgt 3/8 oz Lgt 1-3/4 Dia 7/8 FuelforEN22OPackFU2$198 Fuel EN3 150-8 FU3189 Fuel EN3 158-16 FU3A239 WICKS69 Jetex Engine Book 50 pgs100 BLUEBOOK OF HOBBIES CATALOG 160 TABLOID-SIZE PAGES $395 DEALERS/WHOLESALERS WRITE POIKS 346 BERGEN AVE JERSEY CITY NJ 07304 POLKS HOBBIES 314 Fifth Ave NY NY 10001 DeptMv March1976 85 MUFFIAl RE EXTREMELY COMPACT FULLY ADJUSTABLE NOISE LEVEL AND BACK PRESSURE FOR BETTER PERFORMANCE ADAPTS TO ALL ENGINES FROM 29 TO 60 QUIETER THAN OTHER TYPES OF MUFFLERS UNIVERSAL MUFFLER Designed installation wide variety engines MU-795universal ultimate looks $795 performance MU-795 f No143 ALSO MADE ESPECIALLY FOR OWNERS OF SUPER TIGRE 60 BLUE HEAD ENGINES MU-795ST Fastener Kit ideal way install Du-Bro Universal Mufflaire lete instructions MU-795STNo145 $100 WEBRA 60 R/C ENGINE perfect combination Webra Easiest install MW-750 attaches two hardened steel socket head screws directly thru engine lugs MW-750 No142 $795 0VEL 4 O MINI-MUFFLAIRE engines 09 25MM-595No144 $595 PRODUCTS INCORPORATED'" 480 Bonner Road Wauconda Illinois 60084 USA fidti/iu%fr P 0 D U CT S N C SVILLE ROAD OW GROVE PA 19090 659-3900 NEW. YOULL GET QUITE CHARGE OUT OF THESE Introducing llivans Pylon Brand 12-volt Gel/Cell battery ttery chargertwo great new products flight box See now dealers Gel/Cell Battery Charger Completely dry can never spill leak Never worry about filling water again Lasts full 45 amp hours between recharges Can recharged 1000 times UL listed plugs ordinary house current Fully charges battery 12 hours 500 ma output ideal new battery Can used wet cell batteriestoo start loop airplane going vertically upward 80 up elevator required top loop 310 down elevator necessary air plane going vertically downward 640 up elevator required bottom loop original 100 up elevator will start airplane second loop Compare previous control inputs required perform same size loops 30 ft/sec head wind elevator inputs same points loop 600 740 700 630 600 small elevator input changes required make much easier perfect ioop comparison take look control inputs required perfect loop 30 ft/sec tailwind would take world champion able coordinate substantial control input changes necessary airplane speed loop size wind speed combination results mintmum required control input variation dont really have option make loops too large too small compared what judges looking ever worth investigating charac teristics airplane because opti mum condition may near what judges want can paint three concentric perfectly circular loops sky judges may overlook minor size discrepancy FNWSAER U obby cente oc Last month commented character Class pattern competi tion changed substantially original intent Due difficulty graduating B pattern quality flying proficiency Class has im proved point beginner faces staggering task competing apparently unbeatable group fliers class reaction clubs situation has avoid conflict between truly novice A-pattern fliers good great A-pattern com petitors offering different forms competition common variation standard contest offer Novice Ad vanced Expert categories Class way deciding competes seems vary around country flier competes other fliers nearly same ability has chance win thing dont understand ad vancement points awarded Can clarify situation Another contest variation called Continental Pattern brainchild Canadian Percy Grondin AMA District IX Vice President Jim Mowrey flier makes up own pattern list maneuvers Up 12 maneuvers may chosen list pat tern must include take-off landing perfec tion spot landing maneuver has its own K factor measure difficulty multiplied times score earned maneuver lowest total score flights subtracted high est total score difference divided number categories competi tion resulting number added pro gressively lowest score obtain point spread category Lets try example three categories lowest score 1000 highest 4000 difference 3000 1/3 1000 So categories would 1000-2000 points 2000-3000 points 3000-4000 points Continental Pattern generally al lows fliers nearly same ability compete another equal chance win particular category Un fortunately flier has equal chance lose since few extra points may pro mote flier top category bottom another Nevertheless refreshing approach revitalizing pattern competition Next month plan discuss tech niques determining proper center mass new creation call ing local expert address 12 Connie Dr Shah mar Fla 32579 RC Helicopters continued frnm naoe 19 crash machine right now small washer between collars nylon will provide bearing surface pre vent heat build-up Lubricate tail-rotor bearings flight Yes said flight tail-rotor belt should adjusted just wont slip Check holding main rotor tail rotor Only tighten just wont slip under moderate pres sure probably will find tail boom sandwiched between holding bolts wont easily adjust can improved slotting lower-bolt holes slightly loosened boom slides easily hope article will increase flying pleasure Heli-Baby have developed some hardened tail86 Model Aviation e port continued