IM STARTING off new year intro duction two new column features Janu ary issue first column header will list columns topical contenta table topics sorts youll eventually able search past columns glance items interest prompted reader comments form know read column somewhere hope monthly column prefix will ease search past topics since wont have scan entire writings find item interest end now begin second new column feature will Elec tric connection service idea prompted pattern Ive sensed incoming mail having form Im guy club area flies Electric etters la ment difficulty finding others locally share elation afforded Electric seeking others similar inclina tion Ill happy print name address invite others nearby connect start off Jim Jansen 6525-43rd Ave Kenosha WI 53142 would like hear others nearby Id like encourage other loners would like connect other active unknown Electric locals give forum opportunity help Well give try few months proves worthwhile Ill continue Worthwhile determined folks willing try itso Ill have count input know indeed its worthwhile OK Reader reaction September 89 column has high particular have reacted discussions BEC circuits especially respect Futabas Electric-dedicated re ceiver Battery-eliminator circuits BEC use motor battery power receiver system thereby saving weight separate receiver battery BEC circuits designed shut off motor battery runs out charge before gets low infringe radio operation Heres some follow-up Several readers have expressed concern about much receiver time remains following BEC initiated motor shutdown own Fu taba receiver have opportunity fly several planes So far Ive seen no stance losing receiver power following auto matic motor shutdown However must also say Outside inside views Leisures new Automatic Dual Rate Charger Its peak-detector type two switch-selectable current values charging either receiver packs motor packs Kopski tried motor batteries great satisfaction calls real bargain $85 50 Model Aviation Radio Conoi Electrics Bob Kopski 25 st End Dr Lansdale PA 19446 Bob Rumsey Randolph NJ performed major surgery Great Planes ElectriCUB Kopski calls TurboCUB Motivation Astro geared 15 turning 11 x 7 Rev-Up prop Jomar SC4 speed controller meters juice 13-14 800-mAh Ni-Cds Craft weighs 58 oz wing has no dihedral also strengthened bolted fuselage Note barndoor ailerons Kopski flew found capable prolonged inverted flight unbelievable maneuvers months topics 1 New column features 2 BEC discussion Futaba Electric receiver reader reaction 3 Speed control discussionmore highrate frame-rate 4 Motor electrical noise Chris Trues Astro Mini Challenger built four days Motor cobalt 035 using kits supplied folding prop Chris used Futabas 4NBL radios integral speed controller Astro sells kit either motor Kopski likes kit compact size flights following shutdown have long thermal flightsperhaps about five minutes So least extent can happily report no such problems Readers have also raised flip side questionie much loss motor duration power can saved re ceiver function Well best can observe very little Its probably nearly unmeasurable fact compared motors receivers servos require very little power operate nearly battery resources can still expended motive system cannot say what exact numbers since have attempted measure ment again on-field experience strongly suggests motor getting just about available energy storage So whats few lost seconds motor run time anyway theres question whether bat tery has fully discharged order re charged following BEC operation say No again based field experience Ive seen packs recharged both timed charges peak-detector charges following flight no ev idence difficulty seems clear following BEC shutdown function battery very nearly dead ie ready accept essentially full charge its dead doesnt have enough reserve provide reason able flight duration safe landing So unless youre planning some extended Soaring seems can rest easy issue also Another reader concern has about motor noise affecting Futaba receiver again Ive observed no problems guess Futaba has done good design job regard Yet another point comes up repeatedly limitation number cells usable product Yes its fairly low number seven think remember dont have receivers yet have told some peo ple using up 12 cells outside limits recommended Futaba youre own Finally readers want know builtContinued page 155 Optical isolation signal boosters reduce eliminate interference caused by long leads high power Servos flying wires etc Allows use separate Servo battery receiver mods Especially effective PCM radios using multiple Servos accessories add leads install between Ax Servos Tteet 6wad46te 4t 44Gfz Call write info JOMAR PRODUCTS 513-474-0985 2028 Knightsbridge Dr Cinti OH 45244 B&P Associates Gives Total Flight Line FREEDOM battery needs call write B&P Associates PO Box 22054 Waco TX 76702-2054 817662-5587 new electric starter battery pack cuts cord has always tied starter power panel Discover freedom being able start plane wherever added safety less wire get caught prop charge hefty 4 Ampf hour pack will take through weekend flying power enough spare dont stop have Ni-Cads virtually size imaginable cut experimenter free design whatever takes make yours best setup field Three sizes available Small 1 50 inch Medium 250 Large 350 DPrice 4 ft $295 AThe Fourmost Window Flange flexible black J vinyl strip preformed make perfect flange As well securing window place Fourmost Window Flange provides realistic black outline inconvenience tape Fourmost Window Flange easy install rectangular well contoured windows just razor blade CA adhesive FOURMOST PRODUCTS 4040 24TH AVEFOREST GROVE OR 9711615031 357-2732 January 1990 51 Did ever lose prop screw As tro prop adapter grass flying field case screws Astro charger fits perfectly temporary fix New hub design line folding props made Sonic-Tronics formerly made K&W Hubs now come three inter changeable bushings accommodate wide range motor shaft diameters Nice WINDOW FLANGE some fliers go beyond neck strap use tray support transmitter also pro vides guiding support hands have opportunity see outstanding Scale builder pilot Dennis Crooks flying stable ducted fans note uses transmit ter tray course Hanno Prettner has us ing tray years Enough said RC Electrics/Kopski Continued page 51 Futaba speed control high-rate device dont know plan find out tell next month must say theres high level reader interest high-rate/frame-rate mat ter reaction personal preferences men tioned October column See below So good things Futaba Electric receiver seems have going concerns Yes First question raised reader Harding Orren Rancho Mi rage CA would apply BEC installa tion question concerns fusing power sys tem near batterybefore BEC circuit Yup sure sounds like trouble should fuse blow some reason youre flight did RC would suddenly become Free Flight Frankly despite fact obvious question personally never considered case always fuse right battery its also case dont have BEC de vices use As understand Futaba re ceiver has protection circuitry shut motor down case fault condition occurring However would protect battery RC DESIGNS WEASEL Engine size 40-502 cycle Hardware included Foam Balsa 84 R C DESIGNS 75 Price Dr Wilmington OH 45177 513-382-2158 Hrs 4-8 pm accept 12-8 pm Mon-Fri MasterCard & Visa Saturdays associated wiring ahead receiver should short occur Its something think about now personal preference prefer de termine shut down motor prefer have determined monitor BEC circuit developed preference hard way time someone elses plane out far low BEC circuit did its thing wary folks Keep watch read stopwatch plane good ideaBEC cause youll soon learn its time hang close field Anyway BEC bittersweet very idea having receiver battery weight very appealing independence given simply having supplementary battery pack also very appealing Decisions decisions now heres closing offering Fu taba product As mentioned above designed shut down should overload occur Apparently sensed parameter heat MOS FETS metal-oxide-semiconductor field-effect transistorsEd used speed control circui try get too hot shuts down modeler know running cobalt 05 fairly hard receiver speed control working quite hard motor routinely shut down prematurely corrected situation installing small air scoop near receiver MOSFETS adding corresponding nearby air exit Presto heat consequently shutdown went away speed-control rate matter mentioned October column has brought quite bit reader interestand advance De cember column wont streets about month time January column being written can hardly wait see reader reaction December column Continued January 1990 155 AELECTRIC SEMI-SCALE Radio Control Sport/Trainer Wing span 67 3/4 Length 37 l/2 PAUL K GUILLOW INC WAKEFIELD MA 01880 Pit Special COMPLETELY ENCLOSES Valuable Equipment Holds propelO 18 Acceptscans oriugel Most UsefuL Enclosed Storage wIth Smalleet Size youll LOVE mi KIT$4496 FINISHED KIT --- $5996 ASSEMBLED--. $6996 ASSMiFINISHED -- $7995 HAND MADE IN THE USA Supebly Engineered Hand Crafted flight Support Unts FIRST EVER offered Kit form wfth Beautiful FueProof Finish already applied Available Finiehed Unfinished KNot Assembled Assembled unIts Include gal METAL CAN Unils GUARANTEED against defects Anractre Durable Oak 1/4 Ply Corutruclion Protektor Same high qualily design construction attractive durable oak ply wfth thick black textured foam protect valuable radio equipment Single dual tranamiller unts F~E1T KY finlshd&aasembtedi YOUR SINGLE KIT ......... $2496 DEUCATE DUAL KIT. 996 EQUIPMENT SOL Fin & Assem.. $4496 DUAL Fin & Assem$4996 SASE FREE BROCHURE SEE YOUR LOCAL DEALER OR CALL US JmIaU-JjIW1m11a Conbnentai US [-n 8-b MSI OR dock money order FAST SHIPPING NEAT STUFF 45 16th Street Wt Billings MT 59102 IjII Anyway promised December col umn well now look power system effi ciency differs dramatically depending whether high-rate frame-rate speed controls used Lets approach frame-rate low system efficiencyend help understand frame-rate-type controls cause system inefficiency described last month consider very simple illustration battery motor manual On/Off switch think folks aware motors stalled draw tremendous amount current upon application voltage times normal running current Thus motor initially rest tuming switch causes momentary huge current flow since total circuit resistance time consists internal battery resistance wiring resistance motor winding resistance total several tenths ohm Fortunately large peak current lasts short timea very short time fact its too short normal system fuse blow time short because peak current drops normal running current motor quickly comes up speed Nevertheless lasts circuit losses associated start-up current value en ormous case because losses I-squared-R losses I-squared cur rent times itself phenomenally large start up Thus very short time system effici ency terrible intuitively obvious since initially motor doing nearly nothing battery sure working hard Now imagine turning switch Off repeatedlyas fast little fingers can Clearly average motor current would likely fall somewhere between normal running current stopped-motor current average would relatively high time off time equal motor would aver age see half battery voltage run average half-fast average circuit current would much higher would case half-voltage battery connected motor instead because motor would actually slow down little during off period bad applying voltage stopped motor sudden applica tion voltage below-speed motor would still result repetitive momentarily high current pulsesthe time average also high Now consider switching rate framerate control Its rather low 50 times per sec ond thereabouts faster little fingers could effect still very fast switching rate basic story told above holds albeit lesser degree Moving right along high-rate speed controlone operating very high rate audio ratevastly faster very best fingers could effectthe bad effects mentioned earlier lessen significantly Switching fast mo tor speed does have much chance drop tween voltage pulses therefore high cur rent peaks associated rapid reapplication full motor voltage nearly high oc curs low switching rates Like other things life its relative OK No Theres perhaps its better say Theres additional consideration Most everyone knows motor armature made up number poles wound coils wire armature windings Electrically winding constitutes special electrical com ponent namely inductor operation inductance displays prop erty resisting change current flowing through fact inductors formed ar mature windings tend maintain smoother flow motor current effect relatively small unnoticed low switching speeds However effect quite large high switch ing speeds motor current peaks nearly high under conditions can think effect electrical flywheel wherein circuit current held relatively steady inertia associated en ergy stored armature winding inductance As consequence above very high peak losses associated current peaks low cause current peaks smoothed Indeed significantly improved power system efficien cy obtained high-rate controls described last month realistically due combination both effects described above new No basic idea about inductive effects put forth Roland Boucher RCM article entitled recall Quiet Revolution back Seventies So may new probably start ling have discovered anything re-uncovered must admit however dramatic performance differences pre sented last month have rather amazed some others Ive shared data As said previouslyI can hardly wait reader response Motor noise problems lack thereof also brought considerable reader reaction response October column Perhaps column clear enough because some read ers have wanted know get optocou pIers install Well optocoupler something can simply stick line Speed controls clude device designed necessary peripheral circuitry accommodate othe 156 Model Aviation SFULL LINE OFQUADRA ENGINES PARTS ACCESSORIES SUPERTANKS & SUPERMUFFLERS FULLLINEOFZINGER WOOD PROPS OGIANT SCALE RIO PLANS SEND $100 FOR COMPLETE CA TALOG TO ALLEN SCOTT IDEALER INQUIRIES INVITIED 1iJJDO QUADRA RT 1 NEODESHA KS 66757 25-2821 Free Flight Kits Supplies Rubber er Power Kits Scale Old Timer Too Co2 Electric Motors Rubber Tissue Cox Parts Rubber Accessories Winding Hooks Timers Nitrate Dope CATALOGUE $200 CAMPBELLS CUSTOM KITS PO BOX 5996 LAKE WORTh FL 33466-5996 words optically coupled speed controls must designed way scratch Sorry Please re fer December 1989 column discus sion about installing RF chokes Other reader reaction has taken two sides writing no problems nonoptically coupled controls noth ing problems guess someone has installation noise-free despite hardwired optically coupled speed control its very hard understand optical isolation would ever needed contrary fashion motor noise problems quite aware unpleasant sometimes downright nasty situation can Remember different power systems speed controls radios can act react completely differently fact Ive seen two receivers same manufacture type function differently respect motor noise So fortunate have no such problems please dont conclude gen eral no such problems did youd dead wrongand could happen very next system since should reading some what just prior holidays please accept sincere wishes very happy holiday season great Electric New Year RC Soaring/Blakeslee Continued page 53 handicapping systems used bowling golf hadnt heard being used Soaring until read about Diablo Valley Soar ing Societys new system club contests fine newsletter Thermal Tales Co-editor Pete Thompson explains works executive committee decided needed some way fledglings less experienced fliers feel less intimidated better per forming pilots whole idea course encourage participation have fun club contests Accordingly club has adopted handicap system club contests lieu class system have employed date Objectives 1 Permit members varying skill lev els variable performance capabilities com pete together relatively equal chance winning 2 Provide vehicle assigning members teams desired 3 system should responsive individuals current performance System 1 Normalized score actual raw score di vided perfect score times 1000 2 Fliers average mean last four normalized scores 3 Handicap computed 70% differ ence between fliers average 950 4 Handicap added pilots normalized score determine final score 5 Annual championship determined adding nine best final scores during year Other miscellaneous facets DNF did finish day will included fourmonth rolling average although would part season total Popoffs should allowed everyone handicap over some number like 100 150 Fledglings may turn trans mitters over experienced fliers get out trouble long returned pi lots safe control recovered Handicaps calculated first Diablo Val ley contest under new format ranged low 6 Bob McGowan up high 257 As turned out Bob off day raw score 748 So final score 754 other hand Don Anthony hot day scoring 954 scratch would have won him contest handicaps adding 168 handicap gave him final score 1122 points big winning margin Pete says go ing evaluate system worked 89 maybe reset some parameters 1990 Any other clubs want give try Sportsman Multi-Task news Feedback just starting come SMT activities As probably know 1990 will SMT develop mental year encouraging clubs add some type Distance Speed task traditional Thermal Duration contests lots ways Speed Distance tasks can run below make things equal less intimidating Sportsman fliers SMT Committee recommends 75-oz limit planes Id like print couple recently received items just give flavor whats happen ing first letter Ray Hayes Secre tary LSF After reading October column couldnt resist sending attached article Ray sent copy Dan Pruss Soaring column February 1980 issue Model AviationBE putting SMT contest today Id use --maicnea rerormance system TOP PERFORMANCE K&B tNGINES AirplaneMarine K&B FUELS K&B GLOW PLUGS 9 Blends4 Choices Matched Finish System BEST APPEARANCE K&B FIBERGLASS CLOTH K&B Micro-Balloons FILLER K&B SUPtR POXY RtSIN K&B SUPER POXY THINNER K&B SUPER POXY PRIMER K&B SUPER FOXY PAINT K&B MIXING CUPS January 1990 157 NATIONAL CHAMPION ** THE PIXY HAS DONE IT AGAIN IT WON THE US NATIONALS IN 1989 JUST AS IT DID IN 1985 ESTABLISHING THE PIXY AS THE TOP 2-METER COMPETITION GLIDER TODAY DAVE BANKS IS THE WINNING PILOT FOUR OTHER PIXYS TROPHIEDI 4 MATS WINNERS DAVE BANKS PIXY * laad*lrnpoloeawswoatdsg * * U-AammI Newelettor SECOND WID Ia Now Available SI par year * 21230 Damson Road Bothell WA 98021 206-778-8067 Put Fun Back Fun Fly Get ROUN TUIT Today Its round sflat flies 30 Flying DISC STOL SUPERIOR Small Field FLY Aircraft STABLE PREDICTABLE EtAGILE $43plus *4 shipping TX Res add 7% sales tax VISA Foam ft Lite Ply Construction ELE VON Mixer Included 25- 4B cid 3-3Slbs Accurate QUALITY Materials
Edition: Model Aviation - 1990/01
Page Numbers: 50, 51, 155, 156, 157
IM STARTING off new year intro duction two new column features Janu ary issue first column header will list columns topical contenta table topics sorts youll eventually able search past columns glance items interest prompted reader comments form know read column somewhere hope monthly column prefix will ease search past topics since wont have scan entire writings find item interest end now begin second new column feature will Elec tric connection service idea prompted pattern Ive sensed incoming mail having form Im guy club area flies Electric etters la ment difficulty finding others locally share elation afforded Electric seeking others similar inclina tion Ill happy print name address invite others nearby connect start off Jim Jansen 6525-43rd Ave Kenosha WI 53142 would like hear others nearby Id like encourage other loners would like connect other active unknown Electric locals give forum opportunity help Well give try few months proves worthwhile Ill continue Worthwhile determined folks willing try itso Ill have count input know indeed its worthwhile OK Reader reaction September 89 column has high particular have reacted discussions BEC circuits especially respect Futabas Electric-dedicated re ceiver Battery-eliminator circuits BEC use motor battery power receiver system thereby saving weight separate receiver battery BEC circuits designed shut off motor battery runs out charge before gets low infringe radio operation Heres some follow-up Several readers have expressed concern about much receiver time remains following BEC initiated motor shutdown own Fu taba receiver have opportunity fly several planes So far Ive seen no stance losing receiver power following auto matic motor shutdown However must also say Outside inside views Leisures new Automatic Dual Rate Charger Its peak-detector type two switch-selectable current values charging either receiver packs motor packs Kopski tried motor batteries great satisfaction calls real bargain $85 50 Model Aviation Radio Conoi Electrics Bob Kopski 25 st End Dr Lansdale PA 19446 Bob Rumsey Randolph NJ performed major surgery Great Planes ElectriCUB Kopski calls TurboCUB Motivation Astro geared 15 turning 11 x 7 Rev-Up prop Jomar SC4 speed controller meters juice 13-14 800-mAh Ni-Cds Craft weighs 58 oz wing has no dihedral also strengthened bolted fuselage Note barndoor ailerons Kopski flew found capable prolonged inverted flight unbelievable maneuvers months topics 1 New column features 2 BEC discussion Futaba Electric receiver reader reaction 3 Speed control discussionmore highrate frame-rate 4 Motor electrical noise Chris Trues Astro Mini Challenger built four days Motor cobalt 035 using kits supplied folding prop Chris used Futabas 4NBL radios integral speed controller Astro sells kit either motor Kopski likes kit compact size flights following shutdown have long thermal flightsperhaps about five minutes So least extent can happily report no such problems Readers have also raised flip side questionie much loss motor duration power can saved re ceiver function Well best can observe very little Its probably nearly unmeasurable fact compared motors receivers servos require very little power operate nearly battery resources can still expended motive system cannot say what exact numbers since have attempted measure ment again on-field experience strongly suggests motor getting just about available energy storage So whats few lost seconds motor run time anyway theres question whether bat tery has fully discharged order re charged following BEC operation say No again based field experience Ive seen packs recharged both timed charges peak-detector charges following flight no ev idence difficulty seems clear following BEC shutdown function battery very nearly dead ie ready accept essentially full charge its dead doesnt have enough reserve provide reason able flight duration safe landing So unless youre planning some extended Soaring seems can rest easy issue also Another reader concern has about motor noise affecting Futaba receiver again Ive observed no problems guess Futaba has done good design job regard Yet another point comes up repeatedly limitation number cells usable product Yes its fairly low number seven think remember dont have receivers yet have told some peo ple using up 12 cells outside limits recommended Futaba youre own Finally readers want know builtContinued page 155 Optical isolation signal boosters reduce eliminate interference caused by long leads high power Servos flying wires etc Allows use separate Servo battery receiver mods Especially effective PCM radios using multiple Servos accessories add leads install between Ax Servos Tteet 6wad46te 4t 44Gfz Call write info JOMAR PRODUCTS 513-474-0985 2028 Knightsbridge Dr Cinti OH 45244 B&P Associates Gives Total Flight Line FREEDOM battery needs call write B&P Associates PO Box 22054 Waco TX 76702-2054 817662-5587 new electric starter battery pack cuts cord has always tied starter power panel Discover freedom being able start plane wherever added safety less wire get caught prop charge hefty 4 Ampf hour pack will take through weekend flying power enough spare dont stop have Ni-Cads virtually size imaginable cut experimenter free design whatever takes make yours best setup field Three sizes available Small 1 50 inch Medium 250 Large 350 DPrice 4 ft $295 AThe Fourmost Window Flange flexible black J vinyl strip preformed make perfect flange As well securing window place Fourmost Window Flange provides realistic black outline inconvenience tape Fourmost Window Flange easy install rectangular well contoured windows just razor blade CA adhesive FOURMOST PRODUCTS 4040 24TH AVEFOREST GROVE OR 9711615031 357-2732 January 1990 51 Did ever lose prop screw As tro prop adapter grass flying field case screws Astro charger fits perfectly temporary fix New hub design line folding props made Sonic-Tronics formerly made K&W Hubs now come three inter changeable bushings accommodate wide range motor shaft diameters Nice WINDOW FLANGE some fliers go beyond neck strap use tray support transmitter also pro vides guiding support hands have opportunity see outstanding Scale builder pilot Dennis Crooks flying stable ducted fans note uses transmit ter tray course Hanno Prettner has us ing tray years Enough said RC Electrics/Kopski Continued page 51 Futaba speed control high-rate device dont know plan find out tell next month must say theres high level reader interest high-rate/frame-rate mat ter reaction personal preferences men tioned October column See below So good things Futaba Electric receiver seems have going concerns Yes First question raised reader Harding Orren Rancho Mi rage CA would apply BEC installa tion question concerns fusing power sys tem near batterybefore BEC circuit Yup sure sounds like trouble should fuse blow some reason youre flight did RC would suddenly become Free Flight Frankly despite fact obvious question personally never considered case always fuse right battery its also case dont have BEC de vices use As understand Futaba re ceiver has protection circuitry shut motor down case fault condition occurring However would protect battery RC DESIGNS WEASEL Engine size 40-502 cycle Hardware included Foam Balsa 84 R C DESIGNS 75 Price Dr Wilmington OH 45177 513-382-2158 Hrs 4-8 pm accept 12-8 pm Mon-Fri MasterCard & Visa Saturdays associated wiring ahead receiver should short occur Its something think about now personal preference prefer de termine shut down motor prefer have determined monitor BEC circuit developed preference hard way time someone elses plane out far low BEC circuit did its thing wary folks Keep watch read stopwatch plane good ideaBEC cause youll soon learn its time hang close field Anyway BEC bittersweet very idea having receiver battery weight very appealing independence given simply having supplementary battery pack also very appealing Decisions decisions now heres closing offering Fu taba product As mentioned above designed shut down should overload occur Apparently sensed parameter heat MOS FETS metal-oxide-semiconductor field-effect transistorsEd used speed control circui try get too hot shuts down modeler know running cobalt 05 fairly hard receiver speed control working quite hard motor routinely shut down prematurely corrected situation installing small air scoop near receiver MOSFETS adding corresponding nearby air exit Presto heat consequently shutdown went away speed-control rate matter mentioned October column has brought quite bit reader interestand advance De cember column wont streets about month time January column being written can hardly wait see reader reaction December column Continued January 1990 155 AELECTRIC SEMI-SCALE Radio Control Sport/Trainer Wing span 67 3/4 Length 37 l/2 PAUL K GUILLOW INC WAKEFIELD MA 01880 Pit Special COMPLETELY ENCLOSES Valuable Equipment Holds propelO 18 Acceptscans oriugel Most UsefuL Enclosed Storage wIth Smalleet Size youll LOVE mi KIT$4496 FINISHED KIT --- $5996 ASSEMBLED--. $6996 ASSMiFINISHED -- $7995 HAND MADE IN THE USA Supebly Engineered Hand Crafted flight Support Unts FIRST EVER offered Kit form wfth Beautiful FueProof Finish already applied Available Finiehed Unfinished KNot Assembled Assembled unIts Include gal METAL CAN Unils GUARANTEED against defects Anractre Durable Oak 1/4 Ply Corutruclion Protektor Same high qualily design construction attractive durable oak ply wfth thick black textured foam protect valuable radio equipment Single dual tranamiller unts F~E1T KY finlshd&aasembtedi YOUR SINGLE KIT ......... $2496 DEUCATE DUAL KIT. 996 EQUIPMENT SOL Fin & Assem.. $4496 DUAL Fin & Assem$4996 SASE FREE BROCHURE SEE YOUR LOCAL DEALER OR CALL US JmIaU-JjIW1m11a Conbnentai US [-n 8-b MSI OR dock money order FAST SHIPPING NEAT STUFF 45 16th Street Wt Billings MT 59102 IjII Anyway promised December col umn well now look power system effi ciency differs dramatically depending whether high-rate frame-rate speed controls used Lets approach frame-rate low system efficiencyend help understand frame-rate-type controls cause system inefficiency described last month consider very simple illustration battery motor manual On/Off switch think folks aware motors stalled draw tremendous amount current upon application voltage times normal running current Thus motor initially rest tuming switch causes momentary huge current flow since total circuit resistance time consists internal battery resistance wiring resistance motor winding resistance total several tenths ohm Fortunately large peak current lasts short timea very short time fact its too short normal system fuse blow time short because peak current drops normal running current motor quickly comes up speed Nevertheless lasts circuit losses associated start-up current value en ormous case because losses I-squared-R losses I-squared cur rent times itself phenomenally large start up Thus very short time system effici ency terrible intuitively obvious since initially motor doing nearly nothing battery sure working hard Now imagine turning switch Off repeatedlyas fast little fingers can Clearly average motor current would likely fall somewhere between normal running current stopped-motor current average would relatively high time off time equal motor would aver age see half battery voltage run average half-fast average circuit current would much higher would case half-voltage battery connected motor instead because motor would actually slow down little during off period bad applying voltage stopped motor sudden applica tion voltage below-speed motor would still result repetitive momentarily high current pulsesthe time average also high Now consider switching rate framerate control Its rather low 50 times per sec ond thereabouts faster little fingers could effect still very fast switching rate basic story told above holds albeit lesser degree Moving right along high-rate speed controlone operating very high rate audio ratevastly faster very best fingers could effectthe bad effects mentioned earlier lessen significantly Switching fast mo tor speed does have much chance drop tween voltage pulses therefore high cur rent peaks associated rapid reapplication full motor voltage nearly high oc curs low switching rates Like other things life its relative OK No Theres perhaps its better say Theres additional consideration Most everyone knows motor armature made up number poles wound coils wire armature windings Electrically winding constitutes special electrical com ponent namely inductor operation inductance displays prop erty resisting change current flowing through fact inductors formed ar mature windings tend maintain smoother flow motor current effect relatively small unnoticed low switching speeds However effect quite large high switch ing speeds motor current peaks nearly high under conditions can think effect electrical flywheel wherein circuit current held relatively steady inertia associated en ergy stored armature winding inductance As consequence above very high peak losses associated current peaks low cause current peaks smoothed Indeed significantly improved power system efficien cy obtained high-rate controls described last month realistically due combination both effects described above new No basic idea about inductive effects put forth Roland Boucher RCM article entitled recall Quiet Revolution back Seventies So may new probably start ling have discovered anything re-uncovered must admit however dramatic performance differences pre sented last month have rather amazed some others Ive shared data As said previouslyI can hardly wait reader response Motor noise problems lack thereof also brought considerable reader reaction response October column Perhaps column clear enough because some read ers have wanted know get optocou pIers install Well optocoupler something can simply stick line Speed controls clude device designed necessary peripheral circuitry accommodate othe 156 Model Aviation SFULL LINE OFQUADRA ENGINES PARTS ACCESSORIES SUPERTANKS & SUPERMUFFLERS FULLLINEOFZINGER WOOD PROPS OGIANT SCALE RIO PLANS SEND $100 FOR COMPLETE CA TALOG TO ALLEN SCOTT IDEALER INQUIRIES INVITIED 1iJJDO QUADRA RT 1 NEODESHA KS 66757 25-2821 Free Flight Kits Supplies Rubber er Power Kits Scale Old Timer Too Co2 Electric Motors Rubber Tissue Cox Parts Rubber Accessories Winding Hooks Timers Nitrate Dope CATALOGUE $200 CAMPBELLS CUSTOM KITS PO BOX 5996 LAKE WORTh FL 33466-5996 words optically coupled speed controls must designed way scratch Sorry Please re fer December 1989 column discus sion about installing RF chokes Other reader reaction has taken two sides writing no problems nonoptically coupled controls noth ing problems guess someone has installation noise-free despite hardwired optically coupled speed control its very hard understand optical isolation would ever needed contrary fashion motor noise problems quite aware unpleasant sometimes downright nasty situation can Remember different power systems speed controls radios can act react completely differently fact Ive seen two receivers same manufacture type function differently respect motor noise So fortunate have no such problems please dont conclude gen eral no such problems did youd dead wrongand could happen very next system since should reading some what just prior holidays please accept sincere wishes very happy holiday season great Electric New Year RC Soaring/Blakeslee Continued page 53 handicapping systems used bowling golf hadnt heard being used Soaring until read about Diablo Valley Soar ing Societys new system club contests fine newsletter Thermal Tales Co-editor Pete Thompson explains works executive committee decided needed some way fledglings less experienced fliers feel less intimidated better per forming pilots whole idea course encourage participation have fun club contests Accordingly club has adopted handicap system club contests lieu class system have employed date Objectives 1 Permit members varying skill lev els variable performance capabilities com pete together relatively equal chance winning 2 Provide vehicle assigning members teams desired 3 system should responsive individuals current performance System 1 Normalized score actual raw score di vided perfect score times 1000 2 Fliers average mean last four normalized scores 3 Handicap computed 70% differ ence between fliers average 950 4 Handicap added pilots normalized score determine final score 5 Annual championship determined adding nine best final scores during year Other miscellaneous facets DNF did finish day will included fourmonth rolling average although would part season total Popoffs should allowed everyone handicap over some number like 100 150 Fledglings may turn trans mitters over experienced fliers get out trouble long returned pi lots safe control recovered Handicaps calculated first Diablo Val ley contest under new format ranged low 6 Bob McGowan up high 257 As turned out Bob off day raw score 748 So final score 754 other hand Don Anthony hot day scoring 954 scratch would have won him contest handicaps adding 168 handicap gave him final score 1122 points big winning margin Pete says go ing evaluate system worked 89 maybe reset some parameters 1990 Any other clubs want give try Sportsman Multi-Task news Feedback just starting come SMT activities As probably know 1990 will SMT develop mental year encouraging clubs add some type Distance Speed task traditional Thermal Duration contests lots ways Speed Distance tasks can run below make things equal less intimidating Sportsman fliers SMT Committee recommends 75-oz limit planes Id like print couple recently received items just give flavor whats happen ing first letter Ray Hayes Secre tary LSF After reading October column couldnt resist sending attached article Ray sent copy Dan Pruss Soaring column February 1980 issue Model AviationBE putting SMT contest today Id use --maicnea rerormance system TOP PERFORMANCE K&B tNGINES AirplaneMarine K&B FUELS K&B GLOW PLUGS 9 Blends4 Choices Matched Finish System BEST APPEARANCE K&B FIBERGLASS CLOTH K&B Micro-Balloons FILLER K&B SUPtR POXY RtSIN K&B SUPER POXY THINNER K&B SUPER POXY PRIMER K&B SUPER FOXY PAINT K&B MIXING CUPS January 1990 157 NATIONAL CHAMPION ** THE PIXY HAS DONE IT AGAIN IT WON THE US NATIONALS IN 1989 JUST AS IT DID IN 1985 ESTABLISHING THE PIXY AS THE TOP 2-METER COMPETITION GLIDER TODAY DAVE BANKS IS THE WINNING PILOT FOUR OTHER PIXYS TROPHIEDI 4 MATS WINNERS DAVE BANKS PIXY * laad*lrnpoloeawswoatdsg * * U-AammI Newelettor SECOND WID Ia Now Available SI par year * 21230 Damson Road Bothell WA 98021 206-778-8067 Put Fun Back Fun Fly Get ROUN TUIT Today Its round sflat flies 30 Flying DISC STOL SUPERIOR Small Field FLY Aircraft STABLE PREDICTABLE EtAGILE $43plus *4 shipping TX Res add 7% sales tax VISA Foam ft Lite Ply Construction ELE VON Mixer Included 25- 4B cid 3-3Slbs Accurate QUALITY Materials
Edition: Model Aviation - 1990/01
Page Numbers: 50, 51, 155, 156, 157
IM STARTING off new year intro duction two new column features Janu ary issue first column header will list columns topical contenta table topics sorts youll eventually able search past columns glance items interest prompted reader comments form know read column somewhere hope monthly column prefix will ease search past topics since wont have scan entire writings find item interest end now begin second new column feature will Elec tric connection service idea prompted pattern Ive sensed incoming mail having form Im guy club area flies Electric etters la ment difficulty finding others locally share elation afforded Electric seeking others similar inclina tion Ill happy print name address invite others nearby connect start off Jim Jansen 6525-43rd Ave Kenosha WI 53142 would like hear others nearby Id like encourage other loners would like connect other active unknown Electric locals give forum opportunity help Well give try few months proves worthwhile Ill continue Worthwhile determined folks willing try itso Ill have count input know indeed its worthwhile OK Reader reaction September 89 column has high particular have reacted discussions BEC circuits especially respect Futabas Electric-dedicated re ceiver Battery-eliminator circuits BEC use motor battery power receiver system thereby saving weight separate receiver battery BEC circuits designed shut off motor battery runs out charge before gets low infringe radio operation Heres some follow-up Several readers have expressed concern about much receiver time remains following BEC initiated motor shutdown own Fu taba receiver have opportunity fly several planes So far Ive seen no stance losing receiver power following auto matic motor shutdown However must also say Outside inside views Leisures new Automatic Dual Rate Charger Its peak-detector type two switch-selectable current values charging either receiver packs motor packs Kopski tried motor batteries great satisfaction calls real bargain $85 50 Model Aviation Radio Conoi Electrics Bob Kopski 25 st End Dr Lansdale PA 19446 Bob Rumsey Randolph NJ performed major surgery Great Planes ElectriCUB Kopski calls TurboCUB Motivation Astro geared 15 turning 11 x 7 Rev-Up prop Jomar SC4 speed controller meters juice 13-14 800-mAh Ni-Cds Craft weighs 58 oz wing has no dihedral also strengthened bolted fuselage Note barndoor ailerons Kopski flew found capable prolonged inverted flight unbelievable maneuvers months topics 1 New column features 2 BEC discussion Futaba Electric receiver reader reaction 3 Speed control discussionmore highrate frame-rate 4 Motor electrical noise Chris Trues Astro Mini Challenger built four days Motor cobalt 035 using kits supplied folding prop Chris used Futabas 4NBL radios integral speed controller Astro sells kit either motor Kopski likes kit compact size flights following shutdown have long thermal flightsperhaps about five minutes So least extent can happily report no such problems Readers have also raised flip side questionie much loss motor duration power can saved re ceiver function Well best can observe very little Its probably nearly unmeasurable fact compared motors receivers servos require very little power operate nearly battery resources can still expended motive system cannot say what exact numbers since have attempted measure ment again on-field experience strongly suggests motor getting just about available energy storage So whats few lost seconds motor run time anyway theres question whether bat tery has fully discharged order re charged following BEC operation say No again based field experience Ive seen packs recharged both timed charges peak-detector charges following flight no ev idence difficulty seems clear following BEC shutdown function battery very nearly dead ie ready accept essentially full charge its dead doesnt have enough reserve provide reason able flight duration safe landing So unless youre planning some extended Soaring seems can rest easy issue also Another reader concern has about motor noise affecting Futaba receiver again Ive observed no problems guess Futaba has done good design job regard Yet another point comes up repeatedly limitation number cells usable product Yes its fairly low number seven think remember dont have receivers yet have told some peo ple using up 12 cells outside limits recommended Futaba youre own Finally readers want know builtContinued page 155 Optical isolation signal boosters reduce eliminate interference caused by long leads high power Servos flying wires etc Allows use separate Servo battery receiver mods Especially effective PCM radios using multiple Servos accessories add leads install between Ax Servos Tteet 6wad46te 4t 44Gfz Call write info JOMAR PRODUCTS 513-474-0985 2028 Knightsbridge Dr Cinti OH 45244 B&P Associates Gives Total Flight Line FREEDOM battery needs call write B&P Associates PO Box 22054 Waco TX 76702-2054 817662-5587 new electric starter battery pack cuts cord has always tied starter power panel Discover freedom being able start plane wherever added safety less wire get caught prop charge hefty 4 Ampf hour pack will take through weekend flying power enough spare dont stop have Ni-Cads virtually size imaginable cut experimenter free design whatever takes make yours best setup field Three sizes available Small 1 50 inch Medium 250 Large 350 DPrice 4 ft $295 AThe Fourmost Window Flange flexible black J vinyl strip preformed make perfect flange As well securing window place Fourmost Window Flange provides realistic black outline inconvenience tape Fourmost Window Flange easy install rectangular well contoured windows just razor blade CA adhesive FOURMOST PRODUCTS 4040 24TH AVEFOREST GROVE OR 9711615031 357-2732 January 1990 51 Did ever lose prop screw As tro prop adapter grass flying field case screws Astro charger fits perfectly temporary fix New hub design line folding props made Sonic-Tronics formerly made K&W Hubs now come three inter changeable bushings accommodate wide range motor shaft diameters Nice WINDOW FLANGE some fliers go beyond neck strap use tray support transmitter also pro vides guiding support hands have opportunity see outstanding Scale builder pilot Dennis Crooks flying stable ducted fans note uses transmit ter tray course Hanno Prettner has us ing tray years Enough said RC Electrics/Kopski Continued page 51 Futaba speed control high-rate device dont know plan find out tell next month must say theres high level reader interest high-rate/frame-rate mat ter reaction personal preferences men tioned October column See below So good things Futaba Electric receiver seems have going concerns Yes First question raised reader Harding Orren Rancho Mi rage CA would apply BEC installa tion question concerns fusing power sys tem near batterybefore BEC circuit Yup sure sounds like trouble should fuse blow some reason youre flight did RC would suddenly become Free Flight Frankly despite fact obvious question personally never considered case always fuse right battery its also case dont have BEC de vices use As understand Futaba re ceiver has protection circuitry shut motor down case fault condition occurring However would protect battery RC DESIGNS WEASEL Engine size 40-502 cycle Hardware included Foam Balsa 84 R C DESIGNS 75 Price Dr Wilmington OH 45177 513-382-2158 Hrs 4-8 pm accept 12-8 pm Mon-Fri MasterCard & Visa Saturdays associated wiring ahead receiver should short occur Its something think about now personal preference prefer de termine shut down motor prefer have determined monitor BEC circuit developed preference hard way time someone elses plane out far low BEC circuit did its thing wary folks Keep watch read stopwatch plane good ideaBEC cause youll soon learn its time hang close field Anyway BEC bittersweet very idea having receiver battery weight very appealing independence given simply having supplementary battery pack also very appealing Decisions decisions now heres closing offering Fu taba product As mentioned above designed shut down should overload occur Apparently sensed parameter heat MOS FETS metal-oxide-semiconductor field-effect transistorsEd used speed control circui try get too hot shuts down modeler know running cobalt 05 fairly hard receiver speed control working quite hard motor routinely shut down prematurely corrected situation installing small air scoop near receiver MOSFETS adding corresponding nearby air exit Presto heat consequently shutdown went away speed-control rate matter mentioned October column has brought quite bit reader interestand advance De cember column wont streets about month time January column being written can hardly wait see reader reaction December column Continued January 1990 155 AELECTRIC SEMI-SCALE Radio Control Sport/Trainer Wing span 67 3/4 Length 37 l/2 PAUL K GUILLOW INC WAKEFIELD MA 01880 Pit Special COMPLETELY ENCLOSES Valuable Equipment Holds propelO 18 Acceptscans oriugel Most UsefuL Enclosed Storage wIth Smalleet Size youll LOVE mi KIT$4496 FINISHED KIT --- $5996 ASSEMBLED--. $6996 ASSMiFINISHED -- $7995 HAND MADE IN THE USA Supebly Engineered Hand Crafted flight Support Unts FIRST EVER offered Kit form wfth Beautiful FueProof Finish already applied Available Finiehed Unfinished KNot Assembled Assembled unIts Include gal METAL CAN Unils GUARANTEED against defects Anractre Durable Oak 1/4 Ply Corutruclion Protektor Same high qualily design construction attractive durable oak ply wfth thick black textured foam protect valuable radio equipment Single dual tranamiller unts F~E1T KY finlshd&aasembtedi YOUR SINGLE KIT ......... $2496 DEUCATE DUAL KIT. 996 EQUIPMENT SOL Fin & Assem.. $4496 DUAL Fin & Assem$4996 SASE FREE BROCHURE SEE YOUR LOCAL DEALER OR CALL US JmIaU-JjIW1m11a Conbnentai US [-n 8-b MSI OR dock money order FAST SHIPPING NEAT STUFF 45 16th Street Wt Billings MT 59102 IjII Anyway promised December col umn well now look power system effi ciency differs dramatically depending whether high-rate frame-rate speed controls used Lets approach frame-rate low system efficiencyend help understand frame-rate-type controls cause system inefficiency described last month consider very simple illustration battery motor manual On/Off switch think folks aware motors stalled draw tremendous amount current upon application voltage times normal running current Thus motor initially rest tuming switch causes momentary huge current flow since total circuit resistance time consists internal battery resistance wiring resistance motor winding resistance total several tenths ohm Fortunately large peak current lasts short timea very short time fact its too short normal system fuse blow time short because peak current drops normal running current motor quickly comes up speed Nevertheless lasts circuit losses associated start-up current value en ormous case because losses I-squared-R losses I-squared cur rent times itself phenomenally large start up Thus very short time system effici ency terrible intuitively obvious since initially motor doing nearly nothing battery sure working hard Now imagine turning switch Off repeatedlyas fast little fingers can Clearly average motor current would likely fall somewhere between normal running current stopped-motor current average would relatively high time off time equal motor would aver age see half battery voltage run average half-fast average circuit current would much higher would case half-voltage battery connected motor instead because motor would actually slow down little during off period bad applying voltage stopped motor sudden applica tion voltage below-speed motor would still result repetitive momentarily high current pulsesthe time average also high Now consider switching rate framerate control Its rather low 50 times per sec ond thereabouts faster little fingers could effect still very fast switching rate basic story told above holds albeit lesser degree Moving right along high-rate speed controlone operating very high rate audio ratevastly faster very best fingers could effectthe bad effects mentioned earlier lessen significantly Switching fast mo tor speed does have much chance drop tween voltage pulses therefore high cur rent peaks associated rapid reapplication full motor voltage nearly high oc curs low switching rates Like other things life its relative OK No Theres perhaps its better say Theres additional consideration Most everyone knows motor armature made up number poles wound coils wire armature windings Electrically winding constitutes special electrical com ponent namely inductor operation inductance displays prop erty resisting change current flowing through fact inductors formed ar mature windings tend maintain smoother flow motor current effect relatively small unnoticed low switching speeds However effect quite large high switch ing speeds motor current peaks nearly high under conditions can think effect electrical flywheel wherein circuit current held relatively steady inertia associated en ergy stored armature winding inductance As consequence above very high peak losses associated current peaks low cause current peaks smoothed Indeed significantly improved power system efficien cy obtained high-rate controls described last month realistically due combination both effects described above new No basic idea about inductive effects put forth Roland Boucher RCM article entitled recall Quiet Revolution back Seventies So may new probably start ling have discovered anything re-uncovered must admit however dramatic performance differences pre sented last month have rather amazed some others Ive shared data As said previouslyI can hardly wait reader response Motor noise problems lack thereof also brought considerable reader reaction response October column Perhaps column clear enough because some read ers have wanted know get optocou pIers install Well optocoupler something can simply stick line Speed controls clude device designed necessary peripheral circuitry accommodate othe 156 Model Aviation SFULL LINE OFQUADRA ENGINES PARTS ACCESSORIES SUPERTANKS & SUPERMUFFLERS FULLLINEOFZINGER WOOD PROPS OGIANT SCALE RIO PLANS SEND $100 FOR COMPLETE CA TALOG TO ALLEN SCOTT IDEALER INQUIRIES INVITIED 1iJJDO QUADRA RT 1 NEODESHA KS 66757 25-2821 Free Flight Kits Supplies Rubber er Power Kits Scale Old Timer Too Co2 Electric Motors Rubber Tissue Cox Parts Rubber Accessories Winding Hooks Timers Nitrate Dope CATALOGUE $200 CAMPBELLS CUSTOM KITS PO BOX 5996 LAKE WORTh FL 33466-5996 words optically coupled speed controls must designed way scratch Sorry Please re fer December 1989 column discus sion about installing RF chokes Other reader reaction has taken two sides writing no problems nonoptically coupled controls noth ing problems guess someone has installation noise-free despite hardwired optically coupled speed control its very hard understand optical isolation would ever needed contrary fashion motor noise problems quite aware unpleasant sometimes downright nasty situation can Remember different power systems speed controls radios can act react completely differently fact Ive seen two receivers same manufacture type function differently respect motor noise So fortunate have no such problems please dont conclude gen eral no such problems did youd dead wrongand could happen very next system since should reading some what just prior holidays please accept sincere wishes very happy holiday season great Electric New Year RC Soaring/Blakeslee Continued page 53 handicapping systems used bowling golf hadnt heard being used Soaring until read about Diablo Valley Soar ing Societys new system club contests fine newsletter Thermal Tales Co-editor Pete Thompson explains works executive committee decided needed some way fledglings less experienced fliers feel less intimidated better per forming pilots whole idea course encourage participation have fun club contests Accordingly club has adopted handicap system club contests lieu class system have employed date Objectives 1 Permit members varying skill lev els variable performance capabilities com pete together relatively equal chance winning 2 Provide vehicle assigning members teams desired 3 system should responsive individuals current performance System 1 Normalized score actual raw score di vided perfect score times 1000 2 Fliers average mean last four normalized scores 3 Handicap computed 70% differ ence between fliers average 950 4 Handicap added pilots normalized score determine final score 5 Annual championship determined adding nine best final scores during year Other miscellaneous facets DNF did finish day will included fourmonth rolling average although would part season total Popoffs should allowed everyone handicap over some number like 100 150 Fledglings may turn trans mitters over experienced fliers get out trouble long returned pi lots safe control recovered Handicaps calculated first Diablo Val ley contest under new format ranged low 6 Bob McGowan up high 257 As turned out Bob off day raw score 748 So final score 754 other hand Don Anthony hot day scoring 954 scratch would have won him contest handicaps adding 168 handicap gave him final score 1122 points big winning margin Pete says go ing evaluate system worked 89 maybe reset some parameters 1990 Any other clubs want give try Sportsman Multi-Task news Feedback just starting come SMT activities As probably know 1990 will SMT develop mental year encouraging clubs add some type Distance Speed task traditional Thermal Duration contests lots ways Speed Distance tasks can run below make things equal less intimidating Sportsman fliers SMT Committee recommends 75-oz limit planes Id like print couple recently received items just give flavor whats happen ing first letter Ray Hayes Secre tary LSF After reading October column couldnt resist sending attached article Ray sent copy Dan Pruss Soaring column February 1980 issue Model AviationBE putting SMT contest today Id use --maicnea rerormance system TOP PERFORMANCE K&B tNGINES AirplaneMarine K&B FUELS K&B GLOW PLUGS 9 Blends4 Choices Matched Finish System BEST APPEARANCE K&B FIBERGLASS CLOTH K&B Micro-Balloons FILLER K&B SUPtR POXY RtSIN K&B SUPER POXY THINNER K&B SUPER POXY PRIMER K&B SUPER FOXY PAINT K&B MIXING CUPS January 1990 157 NATIONAL CHAMPION ** THE PIXY HAS DONE IT AGAIN IT WON THE US NATIONALS IN 1989 JUST AS IT DID IN 1985 ESTABLISHING THE PIXY AS THE TOP 2-METER COMPETITION GLIDER TODAY DAVE BANKS IS THE WINNING PILOT FOUR OTHER PIXYS TROPHIEDI 4 MATS WINNERS DAVE BANKS PIXY * laad*lrnpoloeawswoatdsg * * U-AammI Newelettor SECOND WID Ia Now Available SI par year * 21230 Damson Road Bothell WA 98021 206-778-8067 Put Fun Back Fun Fly Get ROUN TUIT Today Its round sflat flies 30 Flying DISC STOL SUPERIOR Small Field FLY Aircraft STABLE PREDICTABLE EtAGILE $43plus *4 shipping TX Res add 7% sales tax VISA Foam ft Lite Ply Construction ELE VON Mixer Included 25- 4B cid 3-3Slbs Accurate QUALITY Materials
Edition: Model Aviation - 1990/01
Page Numbers: 50, 51, 155, 156, 157
IM STARTING off new year intro duction two new column features Janu ary issue first column header will list columns topical contenta table topics sorts youll eventually able search past columns glance items interest prompted reader comments form know read column somewhere hope monthly column prefix will ease search past topics since wont have scan entire writings find item interest end now begin second new column feature will Elec tric connection service idea prompted pattern Ive sensed incoming mail having form Im guy club area flies Electric etters la ment difficulty finding others locally share elation afforded Electric seeking others similar inclina tion Ill happy print name address invite others nearby connect start off Jim Jansen 6525-43rd Ave Kenosha WI 53142 would like hear others nearby Id like encourage other loners would like connect other active unknown Electric locals give forum opportunity help Well give try few months proves worthwhile Ill continue Worthwhile determined folks willing try itso Ill have count input know indeed its worthwhile OK Reader reaction September 89 column has high particular have reacted discussions BEC circuits especially respect Futabas Electric-dedicated re ceiver Battery-eliminator circuits BEC use motor battery power receiver system thereby saving weight separate receiver battery BEC circuits designed shut off motor battery runs out charge before gets low infringe radio operation Heres some follow-up Several readers have expressed concern about much receiver time remains following BEC initiated motor shutdown own Fu taba receiver have opportunity fly several planes So far Ive seen no stance losing receiver power following auto matic motor shutdown However must also say Outside inside views Leisures new Automatic Dual Rate Charger Its peak-detector type two switch-selectable current values charging either receiver packs motor packs Kopski tried motor batteries great satisfaction calls real bargain $85 50 Model Aviation Radio Conoi Electrics Bob Kopski 25 st End Dr Lansdale PA 19446 Bob Rumsey Randolph NJ performed major surgery Great Planes ElectriCUB Kopski calls TurboCUB Motivation Astro geared 15 turning 11 x 7 Rev-Up prop Jomar SC4 speed controller meters juice 13-14 800-mAh Ni-Cds Craft weighs 58 oz wing has no dihedral also strengthened bolted fuselage Note barndoor ailerons Kopski flew found capable prolonged inverted flight unbelievable maneuvers months topics 1 New column features 2 BEC discussion Futaba Electric receiver reader reaction 3 Speed control discussionmore highrate frame-rate 4 Motor electrical noise Chris Trues Astro Mini Challenger built four days Motor cobalt 035 using kits supplied folding prop Chris used Futabas 4NBL radios integral speed controller Astro sells kit either motor Kopski likes kit compact size flights following shutdown have long thermal flightsperhaps about five minutes So least extent can happily report no such problems Readers have also raised flip side questionie much loss motor duration power can saved re ceiver function Well best can observe very little Its probably nearly unmeasurable fact compared motors receivers servos require very little power operate nearly battery resources can still expended motive system cannot say what exact numbers since have attempted measure ment again on-field experience strongly suggests motor getting just about available energy storage So whats few lost seconds motor run time anyway theres question whether bat tery has fully discharged order re charged following BEC operation say No again based field experience Ive seen packs recharged both timed charges peak-detector charges following flight no ev idence difficulty seems clear following BEC shutdown function battery very nearly dead ie ready accept essentially full charge its dead doesnt have enough reserve provide reason able flight duration safe landing So unless youre planning some extended Soaring seems can rest easy issue also Another reader concern has about motor noise affecting Futaba receiver again Ive observed no problems guess Futaba has done good design job regard Yet another point comes up repeatedly limitation number cells usable product Yes its fairly low number seven think remember dont have receivers yet have told some peo ple using up 12 cells outside limits recommended Futaba youre own Finally readers want know builtContinued page 155 Optical isolation signal boosters reduce eliminate interference caused by long leads high power Servos flying wires etc Allows use separate Servo battery receiver mods Especially effective PCM radios using multiple Servos accessories add leads install between Ax Servos Tteet 6wad46te 4t 44Gfz Call write info JOMAR PRODUCTS 513-474-0985 2028 Knightsbridge Dr Cinti OH 45244 B&P Associates Gives Total Flight Line FREEDOM battery needs call write B&P Associates PO Box 22054 Waco TX 76702-2054 817662-5587 new electric starter battery pack cuts cord has always tied starter power panel Discover freedom being able start plane wherever added safety less wire get caught prop charge hefty 4 Ampf hour pack will take through weekend flying power enough spare dont stop have Ni-Cads virtually size imaginable cut experimenter free design whatever takes make yours best setup field Three sizes available Small 1 50 inch Medium 250 Large 350 DPrice 4 ft $295 AThe Fourmost Window Flange flexible black J vinyl strip preformed make perfect flange As well securing window place Fourmost Window Flange provides realistic black outline inconvenience tape Fourmost Window Flange easy install rectangular well contoured windows just razor blade CA adhesive FOURMOST PRODUCTS 4040 24TH AVEFOREST GROVE OR 9711615031 357-2732 January 1990 51 Did ever lose prop screw As tro prop adapter grass flying field case screws Astro charger fits perfectly temporary fix New hub design line folding props made Sonic-Tronics formerly made K&W Hubs now come three inter changeable bushings accommodate wide range motor shaft diameters Nice WINDOW FLANGE some fliers go beyond neck strap use tray support transmitter also pro vides guiding support hands have opportunity see outstanding Scale builder pilot Dennis Crooks flying stable ducted fans note uses transmit ter tray course Hanno Prettner has us ing tray years Enough said RC Electrics/Kopski Continued page 51 Futaba speed control high-rate device dont know plan find out tell next month must say theres high level reader interest high-rate/frame-rate mat ter reaction personal preferences men tioned October column See below So good things Futaba Electric receiver seems have going concerns Yes First question raised reader Harding Orren Rancho Mi rage CA would apply BEC installa tion question concerns fusing power sys tem near batterybefore BEC circuit Yup sure sounds like trouble should fuse blow some reason youre flight did RC would suddenly become Free Flight Frankly despite fact obvious question personally never considered case always fuse right battery its also case dont have BEC de vices use As understand Futaba re ceiver has protection circuitry shut motor down case fault condition occurring However would protect battery RC DESIGNS WEASEL Engine size 40-502 cycle Hardware included Foam Balsa 84 R C DESIGNS 75 Price Dr Wilmington OH 45177 513-382-2158 Hrs 4-8 pm accept 12-8 pm Mon-Fri MasterCard & Visa Saturdays associated wiring ahead receiver should short occur Its something think about now personal preference prefer de termine shut down motor prefer have determined monitor BEC circuit developed preference hard way time someone elses plane out far low BEC circuit did its thing wary folks Keep watch read stopwatch plane good ideaBEC cause youll soon learn its time hang close field Anyway BEC bittersweet very idea having receiver battery weight very appealing independence given simply having supplementary battery pack also very appealing Decisions decisions now heres closing offering Fu taba product As mentioned above designed shut down should overload occur Apparently sensed parameter heat MOS FETS metal-oxide-semiconductor field-effect transistorsEd used speed control circui try get too hot shuts down modeler know running cobalt 05 fairly hard receiver speed control working quite hard motor routinely shut down prematurely corrected situation installing small air scoop near receiver MOSFETS adding corresponding nearby air exit Presto heat consequently shutdown went away speed-control rate matter mentioned October column has brought quite bit reader interestand advance De cember column wont streets about month time January column being written can hardly wait see reader reaction December column Continued January 1990 155 AELECTRIC SEMI-SCALE Radio Control Sport/Trainer Wing span 67 3/4 Length 37 l/2 PAUL K GUILLOW INC WAKEFIELD MA 01880 Pit Special COMPLETELY ENCLOSES Valuable Equipment Holds propelO 18 Acceptscans oriugel Most UsefuL Enclosed Storage wIth Smalleet Size youll LOVE mi KIT$4496 FINISHED KIT --- $5996 ASSEMBLED--. $6996 ASSMiFINISHED -- $7995 HAND MADE IN THE USA Supebly Engineered Hand Crafted flight Support Unts FIRST EVER offered Kit form wfth Beautiful FueProof Finish already applied Available Finiehed Unfinished KNot Assembled Assembled unIts Include gal METAL CAN Unils GUARANTEED against defects Anractre Durable Oak 1/4 Ply Corutruclion Protektor Same high qualily design construction attractive durable oak ply wfth thick black textured foam protect valuable radio equipment Single dual tranamiller unts F~E1T KY finlshd&aasembtedi YOUR SINGLE KIT ......... $2496 DEUCATE DUAL KIT. 996 EQUIPMENT SOL Fin & Assem.. $4496 DUAL Fin & Assem$4996 SASE FREE BROCHURE SEE YOUR LOCAL DEALER OR CALL US JmIaU-JjIW1m11a Conbnentai US [-n 8-b MSI OR dock money order FAST SHIPPING NEAT STUFF 45 16th Street Wt Billings MT 59102 IjII Anyway promised December col umn well now look power system effi ciency differs dramatically depending whether high-rate frame-rate speed controls used Lets approach frame-rate low system efficiencyend help understand frame-rate-type controls cause system inefficiency described last month consider very simple illustration battery motor manual On/Off switch think folks aware motors stalled draw tremendous amount current upon application voltage times normal running current Thus motor initially rest tuming switch causes momentary huge current flow since total circuit resistance time consists internal battery resistance wiring resistance motor winding resistance total several tenths ohm Fortunately large peak current lasts short timea very short time fact its too short normal system fuse blow time short because peak current drops normal running current motor quickly comes up speed Nevertheless lasts circuit losses associated start-up current value en ormous case because losses I-squared-R losses I-squared cur rent times itself phenomenally large start up Thus very short time system effici ency terrible intuitively obvious since initially motor doing nearly nothing battery sure working hard Now imagine turning switch Off repeatedlyas fast little fingers can Clearly average motor current would likely fall somewhere between normal running current stopped-motor current average would relatively high time off time equal motor would aver age see half battery voltage run average half-fast average circuit current would much higher would case half-voltage battery connected motor instead because motor would actually slow down little during off period bad applying voltage stopped motor sudden applica tion voltage below-speed motor would still result repetitive momentarily high current pulsesthe time average also high Now consider switching rate framerate control Its rather low 50 times per sec ond thereabouts faster little fingers could effect still very fast switching rate basic story told above holds albeit lesser degree Moving right along high-rate speed controlone operating very high rate audio ratevastly faster very best fingers could effectthe bad effects mentioned earlier lessen significantly Switching fast mo tor speed does have much chance drop tween voltage pulses therefore high cur rent peaks associated rapid reapplication full motor voltage nearly high oc curs low switching rates Like other things life its relative OK No Theres perhaps its better say Theres additional consideration Most everyone knows motor armature made up number poles wound coils wire armature windings Electrically winding constitutes special electrical com ponent namely inductor operation inductance displays prop erty resisting change current flowing through fact inductors formed ar mature windings tend maintain smoother flow motor current effect relatively small unnoticed low switching speeds However effect quite large high switch ing speeds motor current peaks nearly high under conditions can think effect electrical flywheel wherein circuit current held relatively steady inertia associated en ergy stored armature winding inductance As consequence above very high peak losses associated current peaks low cause current peaks smoothed Indeed significantly improved power system efficien cy obtained high-rate controls described last month realistically due combination both effects described above new No basic idea about inductive effects put forth Roland Boucher RCM article entitled recall Quiet Revolution back Seventies So may new probably start ling have discovered anything re-uncovered must admit however dramatic performance differences pre sented last month have rather amazed some others Ive shared data As said previouslyI can hardly wait reader response Motor noise problems lack thereof also brought considerable reader reaction response October column Perhaps column clear enough because some read ers have wanted know get optocou pIers install Well optocoupler something can simply stick line Speed controls clude device designed necessary peripheral circuitry accommodate othe 156 Model Aviation SFULL LINE OFQUADRA ENGINES PARTS ACCESSORIES SUPERTANKS & SUPERMUFFLERS FULLLINEOFZINGER WOOD PROPS OGIANT SCALE RIO PLANS SEND $100 FOR COMPLETE CA TALOG TO ALLEN SCOTT IDEALER INQUIRIES INVITIED 1iJJDO QUADRA RT 1 NEODESHA KS 66757 25-2821 Free Flight Kits Supplies Rubber er Power Kits Scale Old Timer Too Co2 Electric Motors Rubber Tissue Cox Parts Rubber Accessories Winding Hooks Timers Nitrate Dope CATALOGUE $200 CAMPBELLS CUSTOM KITS PO BOX 5996 LAKE WORTh FL 33466-5996 words optically coupled speed controls must designed way scratch Sorry Please re fer December 1989 column discus sion about installing RF chokes Other reader reaction has taken two sides writing no problems nonoptically coupled controls noth ing problems guess someone has installation noise-free despite hardwired optically coupled speed control its very hard understand optical isolation would ever needed contrary fashion motor noise problems quite aware unpleasant sometimes downright nasty situation can Remember different power systems speed controls radios can act react completely differently fact Ive seen two receivers same manufacture type function differently respect motor noise So fortunate have no such problems please dont conclude gen eral no such problems did youd dead wrongand could happen very next system since should reading some what just prior holidays please accept sincere wishes very happy holiday season great Electric New Year RC Soaring/Blakeslee Continued page 53 handicapping systems used bowling golf hadnt heard being used Soaring until read about Diablo Valley Soar ing Societys new system club contests fine newsletter Thermal Tales Co-editor Pete Thompson explains works executive committee decided needed some way fledglings less experienced fliers feel less intimidated better per forming pilots whole idea course encourage participation have fun club contests Accordingly club has adopted handicap system club contests lieu class system have employed date Objectives 1 Permit members varying skill lev els variable performance capabilities com pete together relatively equal chance winning 2 Provide vehicle assigning members teams desired 3 system should responsive individuals current performance System 1 Normalized score actual raw score di vided perfect score times 1000 2 Fliers average mean last four normalized scores 3 Handicap computed 70% differ ence between fliers average 950 4 Handicap added pilots normalized score determine final score 5 Annual championship determined adding nine best final scores during year Other miscellaneous facets DNF did finish day will included fourmonth rolling average although would part season total Popoffs should allowed everyone handicap over some number like 100 150 Fledglings may turn trans mitters over experienced fliers get out trouble long returned pi lots safe control recovered Handicaps calculated first Diablo Val ley contest under new format ranged low 6 Bob McGowan up high 257 As turned out Bob off day raw score 748 So final score 754 other hand Don Anthony hot day scoring 954 scratch would have won him contest handicaps adding 168 handicap gave him final score 1122 points big winning margin Pete says go ing evaluate system worked 89 maybe reset some parameters 1990 Any other clubs want give try Sportsman Multi-Task news Feedback just starting come SMT activities As probably know 1990 will SMT develop mental year encouraging clubs add some type Distance Speed task traditional Thermal Duration contests lots ways Speed Distance tasks can run below make things equal less intimidating Sportsman fliers SMT Committee recommends 75-oz limit planes Id like print couple recently received items just give flavor whats happen ing first letter Ray Hayes Secre tary LSF After reading October column couldnt resist sending attached article Ray sent copy Dan Pruss Soaring column February 1980 issue Model AviationBE putting SMT contest today Id use --maicnea rerormance system TOP PERFORMANCE K&B tNGINES AirplaneMarine K&B FUELS K&B GLOW PLUGS 9 Blends4 Choices Matched Finish System BEST APPEARANCE K&B FIBERGLASS CLOTH K&B Micro-Balloons FILLER K&B SUPtR POXY RtSIN K&B SUPER POXY THINNER K&B SUPER POXY PRIMER K&B SUPER FOXY PAINT K&B MIXING CUPS January 1990 157 NATIONAL CHAMPION ** THE PIXY HAS DONE IT AGAIN IT WON THE US NATIONALS IN 1989 JUST AS IT DID IN 1985 ESTABLISHING THE PIXY AS THE TOP 2-METER COMPETITION GLIDER TODAY DAVE BANKS IS THE WINNING PILOT FOUR OTHER PIXYS TROPHIEDI 4 MATS WINNERS DAVE BANKS PIXY * laad*lrnpoloeawswoatdsg * * U-AammI Newelettor SECOND WID Ia Now Available SI par year * 21230 Damson Road Bothell WA 98021 206-778-8067 Put Fun Back Fun Fly Get ROUN TUIT Today Its round sflat flies 30 Flying DISC STOL SUPERIOR Small Field FLY Aircraft STABLE PREDICTABLE EtAGILE $43plus *4 shipping TX Res add 7% sales tax VISA Foam ft Lite Ply Construction ELE VON Mixer Included 25- 4B cid 3-3Slbs Accurate QUALITY Materials
Edition: Model Aviation - 1990/01
Page Numbers: 50, 51, 155, 156, 157
IM STARTING off new year intro duction two new column features Janu ary issue first column header will list columns topical contenta table topics sorts youll eventually able search past columns glance items interest prompted reader comments form know read column somewhere hope monthly column prefix will ease search past topics since wont have scan entire writings find item interest end now begin second new column feature will Elec tric connection service idea prompted pattern Ive sensed incoming mail having form Im guy club area flies Electric etters la ment difficulty finding others locally share elation afforded Electric seeking others similar inclina tion Ill happy print name address invite others nearby connect start off Jim Jansen 6525-43rd Ave Kenosha WI 53142 would like hear others nearby Id like encourage other loners would like connect other active unknown Electric locals give forum opportunity help Well give try few months proves worthwhile Ill continue Worthwhile determined folks willing try itso Ill have count input know indeed its worthwhile OK Reader reaction September 89 column has high particular have reacted discussions BEC circuits especially respect Futabas Electric-dedicated re ceiver Battery-eliminator circuits BEC use motor battery power receiver system thereby saving weight separate receiver battery BEC circuits designed shut off motor battery runs out charge before gets low infringe radio operation Heres some follow-up Several readers have expressed concern about much receiver time remains following BEC initiated motor shutdown own Fu taba receiver have opportunity fly several planes So far Ive seen no stance losing receiver power following auto matic motor shutdown However must also say Outside inside views Leisures new Automatic Dual Rate Charger Its peak-detector type two switch-selectable current values charging either receiver packs motor packs Kopski tried motor batteries great satisfaction calls real bargain $85 50 Model Aviation Radio Conoi Electrics Bob Kopski 25 st End Dr Lansdale PA 19446 Bob Rumsey Randolph NJ performed major surgery Great Planes ElectriCUB Kopski calls TurboCUB Motivation Astro geared 15 turning 11 x 7 Rev-Up prop Jomar SC4 speed controller meters juice 13-14 800-mAh Ni-Cds Craft weighs 58 oz wing has no dihedral also strengthened bolted fuselage Note barndoor ailerons Kopski flew found capable prolonged inverted flight unbelievable maneuvers months topics 1 New column features 2 BEC discussion Futaba Electric receiver reader reaction 3 Speed control discussionmore highrate frame-rate 4 Motor electrical noise Chris Trues Astro Mini Challenger built four days Motor cobalt 035 using kits supplied folding prop Chris used Futabas 4NBL radios integral speed controller Astro sells kit either motor Kopski likes kit compact size flights following shutdown have long thermal flightsperhaps about five minutes So least extent can happily report no such problems Readers have also raised flip side questionie much loss motor duration power can saved re ceiver function Well best can observe very little Its probably nearly unmeasurable fact compared motors receivers servos require very little power operate nearly battery resources can still expended motive system cannot say what exact numbers since have attempted measure ment again on-field experience strongly suggests motor getting just about available energy storage So whats few lost seconds motor run time anyway theres question whether bat tery has fully discharged order re charged following BEC operation say No again based field experience Ive seen packs recharged both timed charges peak-detector charges following flight no ev idence difficulty seems clear following BEC shutdown function battery very nearly dead ie ready accept essentially full charge its dead doesnt have enough reserve provide reason able flight duration safe landing So unless youre planning some extended Soaring seems can rest easy issue also Another reader concern has about motor noise affecting Futaba receiver again Ive observed no problems guess Futaba has done good design job regard Yet another point comes up repeatedly limitation number cells usable product Yes its fairly low number seven think remember dont have receivers yet have told some peo ple using up 12 cells outside limits recommended Futaba youre own Finally readers want know builtContinued page 155 Optical isolation signal boosters reduce eliminate interference caused by long leads high power Servos flying wires etc Allows use separate Servo battery receiver mods Especially effective PCM radios using multiple Servos accessories add leads install between Ax Servos Tteet 6wad46te 4t 44Gfz Call write info JOMAR PRODUCTS 513-474-0985 2028 Knightsbridge Dr Cinti OH 45244 B&P Associates Gives Total Flight Line FREEDOM battery needs call write B&P Associates PO Box 22054 Waco TX 76702-2054 817662-5587 new electric starter battery pack cuts cord has always tied starter power panel Discover freedom being able start plane wherever added safety less wire get caught prop charge hefty 4 Ampf hour pack will take through weekend flying power enough spare dont stop have Ni-Cads virtually size imaginable cut experimenter free design whatever takes make yours best setup field Three sizes available Small 1 50 inch Medium 250 Large 350 DPrice 4 ft $295 AThe Fourmost Window Flange flexible black J vinyl strip preformed make perfect flange As well securing window place Fourmost Window Flange provides realistic black outline inconvenience tape Fourmost Window Flange easy install rectangular well contoured windows just razor blade CA adhesive FOURMOST PRODUCTS 4040 24TH AVEFOREST GROVE OR 9711615031 357-2732 January 1990 51 Did ever lose prop screw As tro prop adapter grass flying field case screws Astro charger fits perfectly temporary fix New hub design line folding props made Sonic-Tronics formerly made K&W Hubs now come three inter changeable bushings accommodate wide range motor shaft diameters Nice WINDOW FLANGE some fliers go beyond neck strap use tray support transmitter also pro vides guiding support hands have opportunity see outstanding Scale builder pilot Dennis Crooks flying stable ducted fans note uses transmit ter tray course Hanno Prettner has us ing tray years Enough said RC Electrics/Kopski Continued page 51 Futaba speed control high-rate device dont know plan find out tell next month must say theres high level reader interest high-rate/frame-rate mat ter reaction personal preferences men tioned October column See below So good things Futaba Electric receiver seems have going concerns Yes First question raised reader Harding Orren Rancho Mi rage CA would apply BEC installa tion question concerns fusing power sys tem near batterybefore BEC circuit Yup sure sounds like trouble should fuse blow some reason youre flight did RC would suddenly become Free Flight Frankly despite fact obvious question personally never considered case always fuse right battery its also case dont have BEC de vices use As understand Futaba re ceiver has protection circuitry shut motor down case fault condition occurring However would protect battery RC DESIGNS WEASEL Engine size 40-502 cycle Hardware included Foam Balsa 84 R C DESIGNS 75 Price Dr Wilmington OH 45177 513-382-2158 Hrs 4-8 pm accept 12-8 pm Mon-Fri MasterCard & Visa Saturdays associated wiring ahead receiver should short occur Its something think about now personal preference prefer de termine shut down motor prefer have determined monitor BEC circuit developed preference hard way time someone elses plane out far low BEC circuit did its thing wary folks Keep watch read stopwatch plane good ideaBEC cause youll soon learn its time hang close field Anyway BEC bittersweet very idea having receiver battery weight very appealing independence given simply having supplementary battery pack also very appealing Decisions decisions now heres closing offering Fu taba product As mentioned above designed shut down should overload occur Apparently sensed parameter heat MOS FETS metal-oxide-semiconductor field-effect transistorsEd used speed control circui try get too hot shuts down modeler know running cobalt 05 fairly hard receiver speed control working quite hard motor routinely shut down prematurely corrected situation installing small air scoop near receiver MOSFETS adding corresponding nearby air exit Presto heat consequently shutdown went away speed-control rate matter mentioned October column has brought quite bit reader interestand advance De cember column wont streets about month time January column being written can hardly wait see reader reaction December column Continued January 1990 155 AELECTRIC SEMI-SCALE Radio Control Sport/Trainer Wing span 67 3/4 Length 37 l/2 PAUL K GUILLOW INC WAKEFIELD MA 01880 Pit Special COMPLETELY ENCLOSES Valuable Equipment Holds propelO 18 Acceptscans oriugel Most UsefuL Enclosed Storage wIth Smalleet Size youll LOVE mi KIT$4496 FINISHED KIT --- $5996 ASSEMBLED--. $6996 ASSMiFINISHED -- $7995 HAND MADE IN THE USA Supebly Engineered Hand Crafted flight Support Unts FIRST EVER offered Kit form wfth Beautiful FueProof Finish already applied Available Finiehed Unfinished KNot Assembled Assembled unIts Include gal METAL CAN Unils GUARANTEED against defects Anractre Durable Oak 1/4 Ply Corutruclion Protektor Same high qualily design construction attractive durable oak ply wfth thick black textured foam protect valuable radio equipment Single dual tranamiller unts F~E1T KY finlshd&aasembtedi YOUR SINGLE KIT ......... $2496 DEUCATE DUAL KIT. 996 EQUIPMENT SOL Fin & Assem.. $4496 DUAL Fin & Assem$4996 SASE FREE BROCHURE SEE YOUR LOCAL DEALER OR CALL US JmIaU-JjIW1m11a Conbnentai US [-n 8-b MSI OR dock money order FAST SHIPPING NEAT STUFF 45 16th Street Wt Billings MT 59102 IjII Anyway promised December col umn well now look power system effi ciency differs dramatically depending whether high-rate frame-rate speed controls used Lets approach frame-rate low system efficiencyend help understand frame-rate-type controls cause system inefficiency described last month consider very simple illustration battery motor manual On/Off switch think folks aware motors stalled draw tremendous amount current upon application voltage times normal running current Thus motor initially rest tuming switch causes momentary huge current flow since total circuit resistance time consists internal battery resistance wiring resistance motor winding resistance total several tenths ohm Fortunately large peak current lasts short timea very short time fact its too short normal system fuse blow time short because peak current drops normal running current motor quickly comes up speed Nevertheless lasts circuit losses associated start-up current value en ormous case because losses I-squared-R losses I-squared cur rent times itself phenomenally large start up Thus very short time system effici ency terrible intuitively obvious since initially motor doing nearly nothing battery sure working hard Now imagine turning switch Off repeatedlyas fast little fingers can Clearly average motor current would likely fall somewhere between normal running current stopped-motor current average would relatively high time off time equal motor would aver age see half battery voltage run average half-fast average circuit current would much higher would case half-voltage battery connected motor instead because motor would actually slow down little during off period bad applying voltage stopped motor sudden applica tion voltage below-speed motor would still result repetitive momentarily high current pulsesthe time average also high Now consider switching rate framerate control Its rather low 50 times per sec ond thereabouts faster little fingers could effect still very fast switching rate basic story told above holds albeit lesser degree Moving right along high-rate speed controlone operating very high rate audio ratevastly faster very best fingers could effectthe bad effects mentioned earlier lessen significantly Switching fast mo tor speed does have much chance drop tween voltage pulses therefore high cur rent peaks associated rapid reapplication full motor voltage nearly high oc curs low switching rates Like other things life its relative OK No Theres perhaps its better say Theres additional consideration Most everyone knows motor armature made up number poles wound coils wire armature windings Electrically winding constitutes special electrical com ponent namely inductor operation inductance displays prop erty resisting change current flowing through fact inductors formed ar mature windings tend maintain smoother flow motor current effect relatively small unnoticed low switching speeds However effect quite large high switch ing speeds motor current peaks nearly high under conditions can think effect electrical flywheel wherein circuit current held relatively steady inertia associated en ergy stored armature winding inductance As consequence above very high peak losses associated current peaks low cause current peaks smoothed Indeed significantly improved power system efficien cy obtained high-rate controls described last month realistically due combination both effects described above new No basic idea about inductive effects put forth Roland Boucher RCM article entitled recall Quiet Revolution back Seventies So may new probably start ling have discovered anything re-uncovered must admit however dramatic performance differences pre sented last month have rather amazed some others Ive shared data As said previouslyI can hardly wait reader response Motor noise problems lack thereof also brought considerable reader reaction response October column Perhaps column clear enough because some read ers have wanted know get optocou pIers install Well optocoupler something can simply stick line Speed controls clude device designed necessary peripheral circuitry accommodate othe 156 Model Aviation SFULL LINE OFQUADRA ENGINES PARTS ACCESSORIES SUPERTANKS & SUPERMUFFLERS FULLLINEOFZINGER WOOD PROPS OGIANT SCALE RIO PLANS SEND $100 FOR COMPLETE CA TALOG TO ALLEN SCOTT IDEALER INQUIRIES INVITIED 1iJJDO QUADRA RT 1 NEODESHA KS 66757 25-2821 Free Flight Kits Supplies Rubber er Power Kits Scale Old Timer Too Co2 Electric Motors Rubber Tissue Cox Parts Rubber Accessories Winding Hooks Timers Nitrate Dope CATALOGUE $200 CAMPBELLS CUSTOM KITS PO BOX 5996 LAKE WORTh FL 33466-5996 words optically coupled speed controls must designed way scratch Sorry Please re fer December 1989 column discus sion about installing RF chokes Other reader reaction has taken two sides writing no problems nonoptically coupled controls noth ing problems guess someone has installation noise-free despite hardwired optically coupled speed control its very hard understand optical isolation would ever needed contrary fashion motor noise problems quite aware unpleasant sometimes downright nasty situation can Remember different power systems speed controls radios can act react completely differently fact Ive seen two receivers same manufacture type function differently respect motor noise So fortunate have no such problems please dont conclude gen eral no such problems did youd dead wrongand could happen very next system since should reading some what just prior holidays please accept sincere wishes very happy holiday season great Electric New Year RC Soaring/Blakeslee Continued page 53 handicapping systems used bowling golf hadnt heard being used Soaring until read about Diablo Valley Soar ing Societys new system club contests fine newsletter Thermal Tales Co-editor Pete Thompson explains works executive committee decided needed some way fledglings less experienced fliers feel less intimidated better per forming pilots whole idea course encourage participation have fun club contests Accordingly club has adopted handicap system club contests lieu class system have employed date Objectives 1 Permit members varying skill lev els variable performance capabilities com pete together relatively equal chance winning 2 Provide vehicle assigning members teams desired 3 system should responsive individuals current performance System 1 Normalized score actual raw score di vided perfect score times 1000 2 Fliers average mean last four normalized scores 3 Handicap computed 70% differ ence between fliers average 950 4 Handicap added pilots normalized score determine final score 5 Annual championship determined adding nine best final scores during year Other miscellaneous facets DNF did finish day will included fourmonth rolling average although would part season total Popoffs should allowed everyone handicap over some number like 100 150 Fledglings may turn trans mitters over experienced fliers get out trouble long returned pi lots safe control recovered Handicaps calculated first Diablo Val ley contest under new format ranged low 6 Bob McGowan up high 257 As turned out Bob off day raw score 748 So final score 754 other hand Don Anthony hot day scoring 954 scratch would have won him contest handicaps adding 168 handicap gave him final score 1122 points big winning margin Pete says go ing evaluate system worked 89 maybe reset some parameters 1990 Any other clubs want give try Sportsman Multi-Task news Feedback just starting come SMT activities As probably know 1990 will SMT develop mental year encouraging clubs add some type Distance Speed task traditional Thermal Duration contests lots ways Speed Distance tasks can run below make things equal less intimidating Sportsman fliers SMT Committee recommends 75-oz limit planes Id like print couple recently received items just give flavor whats happen ing first letter Ray Hayes Secre tary LSF After reading October column couldnt resist sending attached article Ray sent copy Dan Pruss Soaring column February 1980 issue Model AviationBE putting SMT contest today Id use --maicnea rerormance system TOP PERFORMANCE K&B tNGINES AirplaneMarine K&B FUELS K&B GLOW PLUGS 9 Blends4 Choices Matched Finish System BEST APPEARANCE K&B FIBERGLASS CLOTH K&B Micro-Balloons FILLER K&B SUPtR POXY RtSIN K&B SUPER POXY THINNER K&B SUPER POXY PRIMER K&B SUPER FOXY PAINT K&B MIXING CUPS January 1990 157 NATIONAL CHAMPION ** THE PIXY HAS DONE IT AGAIN IT WON THE US NATIONALS IN 1989 JUST AS IT DID IN 1985 ESTABLISHING THE PIXY AS THE TOP 2-METER COMPETITION GLIDER TODAY DAVE BANKS IS THE WINNING PILOT FOUR OTHER PIXYS TROPHIEDI 4 MATS WINNERS DAVE BANKS PIXY * laad*lrnpoloeawswoatdsg * * U-AammI Newelettor SECOND WID Ia Now Available SI par year * 21230 Damson Road Bothell WA 98021 206-778-8067 Put Fun Back Fun Fly Get ROUN TUIT Today Its round sflat flies 30 Flying DISC STOL SUPERIOR Small Field FLY Aircraft STABLE PREDICTABLE EtAGILE $43plus *4 shipping TX Res add 7% sales tax VISA Foam ft Lite Ply Construction ELE VON Mixer Included 25- 4B cid 3-3Slbs Accurate QUALITY Materials