IIGeorgeMMyers WHILE BACK promised discuss servo repairs meantime good local fliers also clerks hobby shop kind enough look up tell story seems read January 1977 column first impression such elementary ideas waste good magazine space exchanging radio airplane another chanced pull antenna Guess parted Right little button threaded antenna keep being pulled too far out fuselage takes real man tell stories himself appre ciate way boosted own ego too Thanks Roy Back servos January column identified four servos needed work incidentally tables 1 2 reversed printing Im sure noticed slow sticky rest jumpy noisy Lets start Slow Sticky Back August 1975 column showed measure servo transit time might want look up Clear space workbench lay down clean towel pillowcase work will catch dropped parts fore can bounce floor Provide yourself good light strong magni fying glass assortment screw drivers hex wrenches see Fig 3 Take apart servo time wont have worry about leaving parts out putting something doesnt belong Carefully dismantle servo first attempt its good idea make rough sketch parts come off provide yourself exploded view servo can used assembly aid Make sketch big because youll adding details recognize importance Fig 5 As part removed clean care fully examine damage magnifying glass will looking cracks around screw holes stripped threads bulged distorted cases bent thinned-out gear teeth broken wires par ticularly plug point wire bent cracked printed circuit boards loose components Pay partic ular attention surface feedback potentiometer wiper As wiper wears flat will appear contacting surface Fig 6 track metal par ticles will laid down resistor can wipe off metal particles look grooves and/or hairline cracks metal surface resistor find replace resistor paying particular attention color coding three wires locations solder tabs Worn potentiometers common cause erratic servo operation As contact surfaces metal potentiometer wiper wear tension lost another cause erratic operation Careful bending about 1/16 inch above original position will restore like-new performance must judge yourself wear excessive time has come replace wiper general should no chance will wear through before next inspect because piece might released could cause really erratic operation servo now should have broken down servo its basic elements can prepare chart needed repairs something like Fig 7 will help write up order needed parts can Left Fig 1Ten years progress design Contain same func tional elements amplifier motor gears out-put arm feedback potentiometer Good servo maintenance spells reliability Below 1 Fig 2The Cannon micro-servo shows state-of-the-art miniaturization continues same functional elements old er models elements called out Bottom Fig 3World Engines S-lO servo dismantled inspection tools will need paper towel catch dropped parts mag nifying glass assorted cross-point single-blade hex-wrench screw drivers Required common sense systematic approach 10 Model Aviation guide some intelligent parts swap ping want put things back gether make much operating system possible what youve got Now motor Its possible dis mantle some servo motors make re pairs usually isnt worth effort first place remove arma ture permanent-magnet field will permanently reduce magnetism resultant loss servo speed power try service motor out removing armature take big chance getting dirt will definitely have trouble getting brushes back commutator causing some kind damage Nonetheless may out woods somewhere summer either fix motor dont fly case reasonable services perform will wash oil off commutator rubbing alcohol will have scrub off carbon track may have devel oped using pencil eraser Watch rubber crumbs go because dont want motor Re-assembling motor will require some kind tool hold back brush springs got away bent paper clip got motor apart brushholder end probably held three very tiny set-screws Therefore will have adjust time until motor runs same speed both directions Its fussy work can Slow servos practically always due motors need service very best service remove replace Replacements usually cost about $6 al though prices going up replace servo motor pay careful attention color coding both wires ter minals motor get wires backwards motor will run end its travel stay leave connected operating system too long connected backwards good chance will burn up output transistors Remember can always check against another servo Im going assume have re placed motor Slow Sticky servo ready put things back together Gears next problem sticking jamming turn output arm against gear train motor removed find out Gear damage can very subtle new set Continued page 79 Th 0 J BACK OF THIS GEAR IS UNDER CUT SPONGE POTENTIOMETERBLUE RESISTORBLUE 4BV PLASTIC BODY WIPER NAILTRACKS OF METAL DUST WORN OFF WIPER REMOVE REGULARLY RESISTANCE PLASTIC BODY POTENTIOMETER RESISTOR FIG 6 TYPICAL FEEDBACK POTENTIOMETER Fig 7 Typical Check-List SERVONO Case OK OK OK OK Output Arm/WheelReplace OK OK OK GrommetsReplaceReplaceReplaceReplace MotorReplace OK OK OK Gears OK OKReplace OK PotentiometerCleanedReplaceCleaned OK Plug/Wires OK OK OK Fix Amplifier OK OK OK OK April 1977 11 Fig 4 series cardboard deltas built Bruce Glassmire features rudder elevator throttle control will loop roll Enya 45 slow steady vicious stall FIG 5 WORLD ENGINES S-Ia SERVO YOU CANT GET ANY LIGHTER SMALLER OR SIMPLER THAN THIS pulse commander quality American made rudder-ony pulse proportional radio system offers lightest weight smallest size flute pack available Only 21 oz total airborne weight Baby system Rudder-only flying perfect way start R/C also provides relaxing changeof-pace experienced flyer units come completely wired tested guaranteed ni-cd batteries charger furnished flute pack Transmitter battery included Eveready No 276 9V dry battery equivalent required systems $75 complete Available 72080 72160 72240 72320 72400 72960 75640 531 532 533 534 535 MHz Ham license required 53MHz frequencies BABY 10G75 Airborne weight21 oz 595 g 010 Pee Wee 020 planes up 36 span BABY TWIN 10G75T Airborne weight23 oz 652 g 020 slow flying 049 planes up 40 span NOTE 27 MHz systems still available Baby lOGiS $6995 Baby Twin 10015T $7295 Standard 10G16 $7195 Stompar lOG 17 $7495 Plus send complete atalog Enclosed SIU refunded NAME first order Add $50 1st class null return add $100 handling other Aowss hprdars STANDARD 10G76 Airborne weight31 oz 88 g Babe Bee slow flying Tee Dee 049 planes up 42 span STOMPER 10G77 Airborne weight35 oz 992 g hot 049 slow flying l5ships Radio Technique/Myers Continued page 11 gears usually costs about $3 replac ing doubtful set cheap insurance George say keep up Ill have all-new servo Yep want new performance dont Which important gallon fuel can fly bad servo good servo Since have new motor gears next item case put Are satisfied wont come apart flight Good Lets install feed back potentiometer wiper assembly called nail trade usually plugs plastic shaft accepts output wheel arm opposite end Its position output arm centered determines approximate position resistor should take placed its cavity minor adjustment either nail resistor will required after servo assem bled order get servos centered same position Some manufacturers assemble potentiometers dry others use special grease obtainable Ace R/C prefer grease respect arguments dont Con ductive-plastic potentiometers always assembled dry thats left now stuff ampli fier place close up case very careful replace foam plastic sulation plates avoid shorting something expensive have deliberately avoided dis cussing amplifier repairs first place IC Integrated Circuit amplifiers essentially unrepairable have am plifier trouble best thing replace whole thing Amplifier kits avail able Royal Ace R/C Heath others like tinker save 2 3 dollars Practically manu facturer sells built-up replacement ampli fiers less $20 repair wires plugs has discussed several previous columns case servos using molded plugs whole pigtail plug wires avail able about $3 As re-install screws please turn counter-clockwise first until feel threads engage turn clockwise complete fasten ing avoids cross-threading always danger working plas tics thats left consider soft rubber grommets used mount servos lost broken have hardened replace will minimize potentiometer wear keep nice soft grommets job above discussion have con sidered things cause ser vos become slow jumpy erratic Basically things look order loose dirty plugs wires half strands broken inside insulation dirty worn cracked potentio meter resistors potentiometer wipers have lost tension either through vi bration wear Often find poten tiometer problems servo will spread throughout system make other marginal servos act jumpy Good maintenance primarily matter common sense systematic study accept necessary chore just like wiping off castor oil occasionally make time will rewarded long reliable service equip ment Incidentally charge batteries once month whether using battery packs short out winter storage ever damaged over-charging Thats month gang Send ideas column to. George M Myers 70 Froehlich Farm Rd Hicks yule NY 11801 RC Sport/Van Putte Continued page 17 dont have eye-hand coordination good pattern flying no matter much April 1977 79 AU II Em]
Edition: Model Aviation - 1977/04
Page Numbers: 10, 11, 79
IIGeorgeMMyers WHILE BACK promised discuss servo repairs meantime good local fliers also clerks hobby shop kind enough look up tell story seems read January 1977 column first impression such elementary ideas waste good magazine space exchanging radio airplane another chanced pull antenna Guess parted Right little button threaded antenna keep being pulled too far out fuselage takes real man tell stories himself appre ciate way boosted own ego too Thanks Roy Back servos January column identified four servos needed work incidentally tables 1 2 reversed printing Im sure noticed slow sticky rest jumpy noisy Lets start Slow Sticky Back August 1975 column showed measure servo transit time might want look up Clear space workbench lay down clean towel pillowcase work will catch dropped parts fore can bounce floor Provide yourself good light strong magni fying glass assortment screw drivers hex wrenches see Fig 3 Take apart servo time wont have worry about leaving parts out putting something doesnt belong Carefully dismantle servo first attempt its good idea make rough sketch parts come off provide yourself exploded view servo can used assembly aid Make sketch big because youll adding details recognize importance Fig 5 As part removed clean care fully examine damage magnifying glass will looking cracks around screw holes stripped threads bulged distorted cases bent thinned-out gear teeth broken wires par ticularly plug point wire bent cracked printed circuit boards loose components Pay partic ular attention surface feedback potentiometer wiper As wiper wears flat will appear contacting surface Fig 6 track metal par ticles will laid down resistor can wipe off metal particles look grooves and/or hairline cracks metal surface resistor find replace resistor paying particular attention color coding three wires locations solder tabs Worn potentiometers common cause erratic servo operation As contact surfaces metal potentiometer wiper wear tension lost another cause erratic operation Careful bending about 1/16 inch above original position will restore like-new performance must judge yourself wear excessive time has come replace wiper general should no chance will wear through before next inspect because piece might released could cause really erratic operation servo now should have broken down servo its basic elements can prepare chart needed repairs something like Fig 7 will help write up order needed parts can Left Fig 1Ten years progress design Contain same func tional elements amplifier motor gears out-put arm feedback potentiometer Good servo maintenance spells reliability Below 1 Fig 2The Cannon micro-servo shows state-of-the-art miniaturization continues same functional elements old er models elements called out Bottom Fig 3World Engines S-lO servo dismantled inspection tools will need paper towel catch dropped parts mag nifying glass assorted cross-point single-blade hex-wrench screw drivers Required common sense systematic approach 10 Model Aviation guide some intelligent parts swap ping want put things back gether make much operating system possible what youve got Now motor Its possible dis mantle some servo motors make re pairs usually isnt worth effort first place remove arma ture permanent-magnet field will permanently reduce magnetism resultant loss servo speed power try service motor out removing armature take big chance getting dirt will definitely have trouble getting brushes back commutator causing some kind damage Nonetheless may out woods somewhere summer either fix motor dont fly case reasonable services perform will wash oil off commutator rubbing alcohol will have scrub off carbon track may have devel oped using pencil eraser Watch rubber crumbs go because dont want motor Re-assembling motor will require some kind tool hold back brush springs got away bent paper clip got motor apart brushholder end probably held three very tiny set-screws Therefore will have adjust time until motor runs same speed both directions Its fussy work can Slow servos practically always due motors need service very best service remove replace Replacements usually cost about $6 al though prices going up replace servo motor pay careful attention color coding both wires ter minals motor get wires backwards motor will run end its travel stay leave connected operating system too long connected backwards good chance will burn up output transistors Remember can always check against another servo Im going assume have re placed motor Slow Sticky servo ready put things back together Gears next problem sticking jamming turn output arm against gear train motor removed find out Gear damage can very subtle new set Continued page 79 Th 0 J BACK OF THIS GEAR IS UNDER CUT SPONGE POTENTIOMETERBLUE RESISTORBLUE 4BV PLASTIC BODY WIPER NAILTRACKS OF METAL DUST WORN OFF WIPER REMOVE REGULARLY RESISTANCE PLASTIC BODY POTENTIOMETER RESISTOR FIG 6 TYPICAL FEEDBACK POTENTIOMETER Fig 7 Typical Check-List SERVONO Case OK OK OK OK Output Arm/WheelReplace OK OK OK GrommetsReplaceReplaceReplaceReplace MotorReplace OK OK OK Gears OK OKReplace OK PotentiometerCleanedReplaceCleaned OK Plug/Wires OK OK OK Fix Amplifier OK OK OK OK April 1977 11 Fig 4 series cardboard deltas built Bruce Glassmire features rudder elevator throttle control will loop roll Enya 45 slow steady vicious stall FIG 5 WORLD ENGINES S-Ia SERVO YOU CANT GET ANY LIGHTER SMALLER OR SIMPLER THAN THIS pulse commander quality American made rudder-ony pulse proportional radio system offers lightest weight smallest size flute pack available Only 21 oz total airborne weight Baby system Rudder-only flying perfect way start R/C also provides relaxing changeof-pace experienced flyer units come completely wired tested guaranteed ni-cd batteries charger furnished flute pack Transmitter battery included Eveready No 276 9V dry battery equivalent required systems $75 complete Available 72080 72160 72240 72320 72400 72960 75640 531 532 533 534 535 MHz Ham license required 53MHz frequencies BABY 10G75 Airborne weight21 oz 595 g 010 Pee Wee 020 planes up 36 span BABY TWIN 10G75T Airborne weight23 oz 652 g 020 slow flying 049 planes up 40 span NOTE 27 MHz systems still available Baby lOGiS $6995 Baby Twin 10015T $7295 Standard 10G16 $7195 Stompar lOG 17 $7495 Plus send complete atalog Enclosed SIU refunded NAME first order Add $50 1st class null return add $100 handling other Aowss hprdars STANDARD 10G76 Airborne weight31 oz 88 g Babe Bee slow flying Tee Dee 049 planes up 42 span STOMPER 10G77 Airborne weight35 oz 992 g hot 049 slow flying l5ships Radio Technique/Myers Continued page 11 gears usually costs about $3 replac ing doubtful set cheap insurance George say keep up Ill have all-new servo Yep want new performance dont Which important gallon fuel can fly bad servo good servo Since have new motor gears next item case put Are satisfied wont come apart flight Good Lets install feed back potentiometer wiper assembly called nail trade usually plugs plastic shaft accepts output wheel arm opposite end Its position output arm centered determines approximate position resistor should take placed its cavity minor adjustment either nail resistor will required after servo assem bled order get servos centered same position Some manufacturers assemble potentiometers dry others use special grease obtainable Ace R/C prefer grease respect arguments dont Con ductive-plastic potentiometers always assembled dry thats left now stuff ampli fier place close up case very careful replace foam plastic sulation plates avoid shorting something expensive have deliberately avoided dis cussing amplifier repairs first place IC Integrated Circuit amplifiers essentially unrepairable have am plifier trouble best thing replace whole thing Amplifier kits avail able Royal Ace R/C Heath others like tinker save 2 3 dollars Practically manu facturer sells built-up replacement ampli fiers less $20 repair wires plugs has discussed several previous columns case servos using molded plugs whole pigtail plug wires avail able about $3 As re-install screws please turn counter-clockwise first until feel threads engage turn clockwise complete fasten ing avoids cross-threading always danger working plas tics thats left consider soft rubber grommets used mount servos lost broken have hardened replace will minimize potentiometer wear keep nice soft grommets job above discussion have con sidered things cause ser vos become slow jumpy erratic Basically things look order loose dirty plugs wires half strands broken inside insulation dirty worn cracked potentio meter resistors potentiometer wipers have lost tension either through vi bration wear Often find poten tiometer problems servo will spread throughout system make other marginal servos act jumpy Good maintenance primarily matter common sense systematic study accept necessary chore just like wiping off castor oil occasionally make time will rewarded long reliable service equip ment Incidentally charge batteries once month whether using battery packs short out winter storage ever damaged over-charging Thats month gang Send ideas column to. George M Myers 70 Froehlich Farm Rd Hicks yule NY 11801 RC Sport/Van Putte Continued page 17 dont have eye-hand coordination good pattern flying no matter much April 1977 79 AU II Em]
Edition: Model Aviation - 1977/04
Page Numbers: 10, 11, 79
IIGeorgeMMyers WHILE BACK promised discuss servo repairs meantime good local fliers also clerks hobby shop kind enough look up tell story seems read January 1977 column first impression such elementary ideas waste good magazine space exchanging radio airplane another chanced pull antenna Guess parted Right little button threaded antenna keep being pulled too far out fuselage takes real man tell stories himself appre ciate way boosted own ego too Thanks Roy Back servos January column identified four servos needed work incidentally tables 1 2 reversed printing Im sure noticed slow sticky rest jumpy noisy Lets start Slow Sticky Back August 1975 column showed measure servo transit time might want look up Clear space workbench lay down clean towel pillowcase work will catch dropped parts fore can bounce floor Provide yourself good light strong magni fying glass assortment screw drivers hex wrenches see Fig 3 Take apart servo time wont have worry about leaving parts out putting something doesnt belong Carefully dismantle servo first attempt its good idea make rough sketch parts come off provide yourself exploded view servo can used assembly aid Make sketch big because youll adding details recognize importance Fig 5 As part removed clean care fully examine damage magnifying glass will looking cracks around screw holes stripped threads bulged distorted cases bent thinned-out gear teeth broken wires par ticularly plug point wire bent cracked printed circuit boards loose components Pay partic ular attention surface feedback potentiometer wiper As wiper wears flat will appear contacting surface Fig 6 track metal par ticles will laid down resistor can wipe off metal particles look grooves and/or hairline cracks metal surface resistor find replace resistor paying particular attention color coding three wires locations solder tabs Worn potentiometers common cause erratic servo operation As contact surfaces metal potentiometer wiper wear tension lost another cause erratic operation Careful bending about 1/16 inch above original position will restore like-new performance must judge yourself wear excessive time has come replace wiper general should no chance will wear through before next inspect because piece might released could cause really erratic operation servo now should have broken down servo its basic elements can prepare chart needed repairs something like Fig 7 will help write up order needed parts can Left Fig 1Ten years progress design Contain same func tional elements amplifier motor gears out-put arm feedback potentiometer Good servo maintenance spells reliability Below 1 Fig 2The Cannon micro-servo shows state-of-the-art miniaturization continues same functional elements old er models elements called out Bottom Fig 3World Engines S-lO servo dismantled inspection tools will need paper towel catch dropped parts mag nifying glass assorted cross-point single-blade hex-wrench screw drivers Required common sense systematic approach 10 Model Aviation guide some intelligent parts swap ping want put things back gether make much operating system possible what youve got Now motor Its possible dis mantle some servo motors make re pairs usually isnt worth effort first place remove arma ture permanent-magnet field will permanently reduce magnetism resultant loss servo speed power try service motor out removing armature take big chance getting dirt will definitely have trouble getting brushes back commutator causing some kind damage Nonetheless may out woods somewhere summer either fix motor dont fly case reasonable services perform will wash oil off commutator rubbing alcohol will have scrub off carbon track may have devel oped using pencil eraser Watch rubber crumbs go because dont want motor Re-assembling motor will require some kind tool hold back brush springs got away bent paper clip got motor apart brushholder end probably held three very tiny set-screws Therefore will have adjust time until motor runs same speed both directions Its fussy work can Slow servos practically always due motors need service very best service remove replace Replacements usually cost about $6 al though prices going up replace servo motor pay careful attention color coding both wires ter minals motor get wires backwards motor will run end its travel stay leave connected operating system too long connected backwards good chance will burn up output transistors Remember can always check against another servo Im going assume have re placed motor Slow Sticky servo ready put things back together Gears next problem sticking jamming turn output arm against gear train motor removed find out Gear damage can very subtle new set Continued page 79 Th 0 J BACK OF THIS GEAR IS UNDER CUT SPONGE POTENTIOMETERBLUE RESISTORBLUE 4BV PLASTIC BODY WIPER NAILTRACKS OF METAL DUST WORN OFF WIPER REMOVE REGULARLY RESISTANCE PLASTIC BODY POTENTIOMETER RESISTOR FIG 6 TYPICAL FEEDBACK POTENTIOMETER Fig 7 Typical Check-List SERVONO Case OK OK OK OK Output Arm/WheelReplace OK OK OK GrommetsReplaceReplaceReplaceReplace MotorReplace OK OK OK Gears OK OKReplace OK PotentiometerCleanedReplaceCleaned OK Plug/Wires OK OK OK Fix Amplifier OK OK OK OK April 1977 11 Fig 4 series cardboard deltas built Bruce Glassmire features rudder elevator throttle control will loop roll Enya 45 slow steady vicious stall FIG 5 WORLD ENGINES S-Ia SERVO YOU CANT GET ANY LIGHTER SMALLER OR SIMPLER THAN THIS pulse commander quality American made rudder-ony pulse proportional radio system offers lightest weight smallest size flute pack available Only 21 oz total airborne weight Baby system Rudder-only flying perfect way start R/C also provides relaxing changeof-pace experienced flyer units come completely wired tested guaranteed ni-cd batteries charger furnished flute pack Transmitter battery included Eveready No 276 9V dry battery equivalent required systems $75 complete Available 72080 72160 72240 72320 72400 72960 75640 531 532 533 534 535 MHz Ham license required 53MHz frequencies BABY 10G75 Airborne weight21 oz 595 g 010 Pee Wee 020 planes up 36 span BABY TWIN 10G75T Airborne weight23 oz 652 g 020 slow flying 049 planes up 40 span NOTE 27 MHz systems still available Baby lOGiS $6995 Baby Twin 10015T $7295 Standard 10G16 $7195 Stompar lOG 17 $7495 Plus send complete atalog Enclosed SIU refunded NAME first order Add $50 1st class null return add $100 handling other Aowss hprdars STANDARD 10G76 Airborne weight31 oz 88 g Babe Bee slow flying Tee Dee 049 planes up 42 span STOMPER 10G77 Airborne weight35 oz 992 g hot 049 slow flying l5ships Radio Technique/Myers Continued page 11 gears usually costs about $3 replac ing doubtful set cheap insurance George say keep up Ill have all-new servo Yep want new performance dont Which important gallon fuel can fly bad servo good servo Since have new motor gears next item case put Are satisfied wont come apart flight Good Lets install feed back potentiometer wiper assembly called nail trade usually plugs plastic shaft accepts output wheel arm opposite end Its position output arm centered determines approximate position resistor should take placed its cavity minor adjustment either nail resistor will required after servo assem bled order get servos centered same position Some manufacturers assemble potentiometers dry others use special grease obtainable Ace R/C prefer grease respect arguments dont Con ductive-plastic potentiometers always assembled dry thats left now stuff ampli fier place close up case very careful replace foam plastic sulation plates avoid shorting something expensive have deliberately avoided dis cussing amplifier repairs first place IC Integrated Circuit amplifiers essentially unrepairable have am plifier trouble best thing replace whole thing Amplifier kits avail able Royal Ace R/C Heath others like tinker save 2 3 dollars Practically manu facturer sells built-up replacement ampli fiers less $20 repair wires plugs has discussed several previous columns case servos using molded plugs whole pigtail plug wires avail able about $3 As re-install screws please turn counter-clockwise first until feel threads engage turn clockwise complete fasten ing avoids cross-threading always danger working plas tics thats left consider soft rubber grommets used mount servos lost broken have hardened replace will minimize potentiometer wear keep nice soft grommets job above discussion have con sidered things cause ser vos become slow jumpy erratic Basically things look order loose dirty plugs wires half strands broken inside insulation dirty worn cracked potentio meter resistors potentiometer wipers have lost tension either through vi bration wear Often find poten tiometer problems servo will spread throughout system make other marginal servos act jumpy Good maintenance primarily matter common sense systematic study accept necessary chore just like wiping off castor oil occasionally make time will rewarded long reliable service equip ment Incidentally charge batteries once month whether using battery packs short out winter storage ever damaged over-charging Thats month gang Send ideas column to. George M Myers 70 Froehlich Farm Rd Hicks yule NY 11801 RC Sport/Van Putte Continued page 17 dont have eye-hand coordination good pattern flying no matter much April 1977 79 AU II Em]