ELECTRIC MEET announcements open months column First up Fifteenth Annual Astro Flight Electric Champs scheduled June 17-18 1989 Fairview Regional Park Costa Mesa CA Events include seven-cell Sailplane Old-Timer Unlimited Sailplane OldTimer contest man-on-man mat serious Electric competitor since encompasses limited motor runs thermal dura tion landing scoring details can obtained writing Harbor Soaring Society 1204 Palm Ave Huntington Beach CA 92648 very same dates June 17-18at opposite end countrywill Second Annual Lehigh Valley Electric Fun-Fly Easton PA near Allentown know what first like Im certainly going second meet welcomes Electrics skill levels simple fun events everyone lots prizes both skill luck can get full details contacting Ellis Grumer 321 Aurora St Phillipsburg NJ 08865 telephone 201 859-0969 call Stan Rauktis 215 252-2024 Next have First Annual BCR/CC Elec tric Fly scheduled July 8 Northern Bur lington County Regional High School sponsored Burlington County Radio Control Club New Jersey too will fun-fly affair low-pressure events information con tact Robert Afflerback 123 Harrington Circle Willingboro NJ 08046 telephone 609 8718777 July 8-9 sees two Midwest Electric Fly com petitionstwo individual days worth Satur day Sunday July 8 9 dual meet wherein Saturday activity sponsored Electric Fliers Only club CD Ken Myers can reach him 313 698-4668 Fun events will include Triple Duration Sail plane Most Beautiful Triple Duration Other Best Non-kit Airplane Best Scale Dual Du ration Sundays event hosted Ann Arbor RC Falcons CD non other Elec tric Grand Master himselfDr Keith Shaw can reach Keith 313 973-6309 Sundays events include All-Up/Last-Down Best Scale Most Impressive Best Finish Most Aerobat ic Both meets Ann Arbor area three bucks gets ya day past column has once cluded representative motor/propeller data has found favorable audience serious Electric modelers month Im offering some specially formatted performance formation will particular interest took advice past refer enced Mitch Polings columns November December 1988 Model Builder magazine Mitch detailed some motor mathematics put forth reader Ed Westbrook fill may have access MB columns Im going generalize supplement some goodies presented begin permanent magnet electric mo tor like ones use electromechanical system displays certain predictable opera tional characteristics resulting the way designed built characteristics can described relatively simple approxi mate mathematical relationship reads like VkxRPMIxR1 simple expression V voltage ap Astros new Model 112 Constant Amp Charger L delivers selectable steady current over timed charge cycle toggle switch panel selects size battery pack being charged 1-14 cellsll4-28 cellsa very large range Author Kopski used collection 05-size motors R get table performance characteristics included months column look alikebut certainly dont perform alike latest Electric trainers market Mirage kit produced Carl Goldberg Models L kit includes motor its wiring harness number formed plastic parts enhance planes appearance Unusually rugged wing has leading edge sheeted balsa both top bottom Kopskis new Skyvolt aerobatic design R pictured last month fully covered red white MonoKote Bare-bones structure no internal equipment weighs 13 oz Acrobatic capabilities retained using wide range power systems 48 Model Aviation Radio Conoi Electrics Bob Kopski 25 West End Dr Lansdale PA 19446 plied motor terminals volts motor current amps RPM course prop rpm above easily determined readily familiar entities nearly Elec tric modeler Ill get R minute So whats k constant directly function makeup motor depen dent number poles number turns armature magnetic makeup motor k neither good nor badit just thats design choice effect k tells us rpm ideal motor will turn volt applied Simply put greater voltage greater proportional rpm course ranges k best suited useturning nominal propellers familiar desirable speeds batteries having practical voltage levels Astute readers surely caught subtlety abovethe word ideal Ideal motors would obey simpler equation VkxRPMorRPM V/k2 Equation 2 literally means ideal motor would produce rpm entirely determined applied voltage value kno matter what prop used such case real life nothing ideal thats R Equation 1 enters picture R equivalent total motor resistance made up mostly armature winding resist ance brush resistance Basically R what makes motor slow down under load easily seen again rewriting Equation 1 thus RPM R k 3 Equation 3 tells us ideal RPM given V k reduced motor current times motor resistance Thus larger prop everyone knows causes motor draw current forces motor slow down simply cause draws current thats R also responsible motor getting hot because motor current flows through resistance generates heat propor tional square current times resis tance I-squared R lost power Ie power taken battery available turn propeller Because I-squared can very large number very important R very small YesR real bad guy armature windings heavy wire high-quality brushes good tight contact commutator Continued page 146 Miter Master * Perfect Truss construction * 900 squaring fence * Triangular adjustable fence Price $1095 Product No 122 Miter Sander Sand angle its complement quickly accurately Miter Master solid alder base mounted non-skid pads alder four-way re versible sliding block carries 2 different grits sand paper 503 357-2732 FOURMOST PRODUCTS 4040 24TH AVE FOREST GROVE OR 97116 a2SOMbRtmts tritrO-i Aederson Co ~Pn0daCtS Inn Only certitied checks ,rooey orders accepted Mintmun order 31200 three packages ot 4 Poeerooles 5350 per package $150 shiporne handling CT resdelfO add 75% sales tan Prices subject change notice hEALER IHOWNEES INVITED Fo further ntornalion dealer prcen send SASS Business Card SERMOS0 R/C SNAP CONNECTORS0 Calar Comma Slatn Box 16787 Stamftxti CT 06935203322-6294 IZiBi- Copter Rubber Band Powered Helicopter Flying repuatibilidy seth ceucut ant reitilts Flys FtRWARD & RACK WARD II HOVERS 5 TURNS can enec Fly INVERTED lre nee 3r FEAIIIRES [7 ot0 ~ hcrdunre ocpplied talsa N Paper Ccslralion Deluled step kyofep,sfrnlios euler ports POE-CUT & DRILLED Bald ArrIrone directly cr11 FULL SIZE PLANS icr f.t esycooenbl July 1989 49 Kopskis servo-operated On/Off motor switch assembly simplicity itself Switch servo affixed plywood plate double-sticky servo tape Small balsa loca tor blocks arrows keep units aligned Sticky-back Velcro strips mount assembly Inside fuselage Pushrod fits through hole bored lever Astro microswitch Wheel collar sets operation just right $975AVAILABLE AT AMERICAS$525 FINEST HOBBY SHOPS OI5TRIBUTEO BY SMIflflHI Z1D5U85ZRD 7550 San Gabriel Rend cadere CA 534fl 455-1717 COMPETITION ACCESSORIES & CUSTOMIZED K&B ENGINES RACING WHEELS KLO7Z OIL CARBON FIBER SOLID LINES ALL KINDS OF FUEL TUBING FOUR BRANDS OF GLOW PLUGS HA RD-TO-FIND HA RD WA RE OLD TIMER SUPPLIES COILS CONDENSERS NGK & STIlT SPARK PLUGS SILK 12 COLORS QUALITY DOPE BRUSHES 5& 7LOOP 1/4RUBBER BANDS TRANSISTOR IGNITION SYSTEMS RESISTOR HIGH TENSION LEADS 1/2A TEXACO PLA YBOY SR KIT 1/2A TEXACO ENGINES & PARTS KSB & IGNITION TIMERS RUBBER POWER KITS PROPS TISSUE AND OTHER SUPPLIES CYANOACRYLATES & EPOXIES ORDER BY MAIL OR PHONE 619 728-4365 SORRY NO COD VISA & MASTERCARD WELCOME MINIMUM MERCHANDISE ORDER $1000 SHIPPING & HANDLING FEE $150 FOR INSURANCE ADD $100 STOCK ORDERS SHIPPED WITHIN 24 HRS VTBEGINNER RACES Instructions Club Programs NORTHEAST AREA Information Contact North East Pylon Racing Organization 119 Dean AveFranklin Mass 02033 506 529-4043 401 739-2653 huh information Banzai can get touch Jerry Banzai Enterprises 2997 Anderson Ave Port Alberni BC Can ada V9Y2V3 Instructional videotapes Have ever won dered cut foam cores vacuum-bag wings build fiberglass fuselages Did decide beyond abilities just wasnt worth trouble Better days ahead Channel 1 Productions Humble TX has made three fantastic videotapes available RC modeler Cutting Foam Cores Making Templates Covers step-by-step technique foam wings plans automatic hands-off foam cutter will give sharp trailing edges will given videotape bonus Vacuum Bag Fiberglass Wings Buy MaterialsThe videotape gives simplified step-by-step way build composite wings model Sailplanes Power planes Making Fiberglass MoldsThis videotape gives ABCs making fiberglass molds what equipment material will need technique teaches allows manufac ture fiberglass part What think Now can build allglass Slope Racer have dreaming about simply replace old beaten-up foam wing glass fuselage tapes will cost $3495 plus $350 shipping buy two videotapes can get third $2495 plus shipping information con tact Julian Tamez Channel Productions 19827 Bishops Gate Suite No 1 Humble TX 77328 telephone 713 278-4575 Canards flying wings next column will devoted entirely flying wings ca nards Although configurations may look little different offer outstanding perform ance Slope flier Along general dis cussion theories behind unique type aircraft will taking look few kits available Just name few Jades Telos ca nard new Shogun flying wing Bob Sealys Javelin flying wing Future Flights Klingberg fly ing wing new Annihilator Slope Racer RC Electrics/Kopski Continued page 49 very important last itemthe good tight contact has by-product another loss frictionbut loss generally much less loss associated poor resistive brush con tact OK what good stuff Its going take column fully illustrate answer now have no choice ask patience may wish save col umn becausecombined future ones II eventually have lots useful info know make best use fu ture Electrics meantime well get start future Some motor performance data fill blanks above information follows result testing done substantial sample 05-size motors theres intolerable meaning less nomenclature again Mitch Poling Model Builder issues previously mentioned used limited data previously published through laborious manipulation simultaneous equa tions derived motor k resistance etc Since Im fortunate have direct ways determining constants decided get detailed education myself addition would save everyone else may inter ested lot work provide accurate val ues constants would otherwise de rived calculation What follows some rele vant data nine motors consisting seven dif ferent so-called 05 models will evident 05 motors created equal Now some words about data associ ated calculations motor first run two values low voltage prop thin flat two-bladed nearly no-load stick stead practical purposes real load motor internal friction cannot eliminated stick looked like prop tach permitted direct rpm mea surement subsequent determination kthe volts-per-rpm constant two rpm values applied voltage readings averaged calcu late ks listed below Following motor run same prop Top Flite 8 x 4 wood exactly 60 volts applied measured brush termi nals done see motors haved relative other would case fictitious fixed cell count throttle set ting Motor current rpm recorded motor current applied 60 volts multiplied give listed input power watts As will see data prop rpm motor input power varied widely over range sample motors Following applied voltage read justed rpm exactly 9000 done see motor efficiency varied required same workie turn same prop same rpm As will see data motors required just about same input power requiring power least efficient motors also ones largest Rexactly what would expected cause R associated power loss power taken battery available prop diverted making motor hot instead As motor R determined ap plying constant 100 amp electronically regu lated current through motor armature held stalled resulting voltage drop present motor terminals recorded 10 times dif ferent angular positions stalled armature done because small voltage drop varies bit commutator position high est lowest readings discarded remaining eight readings averaged av erage voltage divided 10-amp current pro duced R values listed Finally since some may wonder digital instru mentation used throughout data gathering data average believed quite good Certainly comparative data very good case must keep mind looks like motors volved absolute sample size model indeed limited general have no way knowing particular motor used typi cal particularly good bad Since have have no choice con sider representative particular product Also please note motors run shown operation minute two no implication presentation particular product will sustain test levels indicated see Heres closing thought below Measured Calculated Motor Performance C Pwr 5/k"R MotorVoltsAmpsRPMwattsrpm/voltohms cobalt 60 250 11260 150 2303 0051 05 ** 456 165900075 Ooid 60 213 10600 128 2298 0057 Fire-I 474 156900074 146 Model Aviation OUR REV-UP VERA GES OVEji 9000 PROPS III IMMEDIATE SHIPMENT ON VISA/MC SPECIALISTS IN CUSTOM COX TEE DEE & REED ENGINES 020S 049S 051S & 09S ALL CUS TOM & STOCK PARTS VAILABLEINDIVIDUALL Y RACE ILIWANNA Q500F-iFAI 1111 iI E7Vi wuu WE ARE SHOOTING DOWN HIGH BALSA PRICES WITH SUPER QUALITY Satisfaction Guaranteed Direct Only BALSA SN LETS 36 48 30 1162 33 3322 40 182 43 3162 49 14 2 66 1323 37 1203 37 1163 37493i 3323 44 58 37 18 3 5471 45 3163- 628265 143 73 9561 6163 85110 36 3 6812471 12 e3110155 34 3165191 1164 -697648 3324 709468 184 60168 86 3164 9312275 14 411013484 38 4165225138 12 4225261 MATCHED SHEETS 42 3324100 164106 3164120 144131 ALU STICKS 3645 1161409 1163810 1161214 3321410 3323812 3321216 181808 18141116 18381218 18121024 3163161116 316381726 316122230 14141624 14381928 14122130 14343444 1414065 5165167128 38382737 38123246 36344255 381570 12123653 12344662 1215878 58584665 34346790 CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa ~-@ LIGHT 4-6 LB BALSATRIANGLES36 WOOD36 1414251323 53 3836 361203 53 121235116353 343445332363 1 1551/8377 316389 BALSA PLANKS36143104 1185383122 12150123158 13200343242 1428013335 1173275116483 11243603324160 22225184115 233263164133 24435144158 33495384238 34688124322 TAPERED SHEETS36 142 65 14385 382 68 38398 123120 LONE STAREPOXY 90Lot 895 5 noo596 iSo,598 30 rrro596 TRAILING EDGE 36 14132 51611439 3811246 12270 7NTGLUE 1 oo Thck298 1, Th,288 2o Thck550 2oz 5,550 BASSWOOD45 31631626 3161430 3163838 3/161246 3163460 141442 143849 43480 38 3660 381270 3/83490 121290 1234100 BUNDLE DEALS 20-116338698 201164361035 20332 865 15332436955 161/8336735 1018436695 15316336925 10-316436835 1014336655 1014 436830 1538336870 538436655 512336540 5124361080 10332448885 518448500 5-3/1 64 0 514448645 * NEW * Hundreds new sizes accessories finishing materials Send #10 SASE lafest catalog SPRUCE STICKS 36 48 18 81725 18 142026 16 382232 3163162838 14 143450 14 3/84055 141/24565 38 384968 38 126077 12126688 1234 75 87 SPRUCE TRIANGLES 36 3838 47 1212 64 3434 81 186 1 8 12 HARD MAPLE 1438 363 8 3812 3834 1234 BIRCH DOWELS 18 316 14 5 16 38 B 40 45 50 58 68 36 09 14 25 32 3PLYBIRCH48 1-6412620 1 3212445 1 1612455 1812495 SPLVBIRCH 332 12 1/812 316 12 1/412 38 12 1212 48, 598 625 626 625 725 900 LITEPLY 48GROG VEDLOMOUNTS 02 IncheS 155383-41840 3153834532-40 123431645 1412495 LONE STAR MODELS Cont46 Handling Charge UPS Add $300 COD *300 extra PP APO FPO 1623 57th St Lubbock TX 79412 Weaccept Visa Mastercard peesonal checks COD 614% tax Texss US currency Minimum Wood Oedar $1000 6Ygp Gold6022310700 Fire-2 483 1549000 HP60389960 00 497 1489000 Hyper- 603398320 rhrsl 6601449000 Kyosho 6023930960 3605T449369000 Thrst- 603649930 fl3dsler 5203399000 Trbo 603609090 530-I 5991549000 Trbo 601519390 550-2 5921459000 Notes listed alphabelically l limed 333 74 308 74 71 95 343 72 98 72 96 92 93 86 2332 2320 3809 2350 2076 2049 2039 0060 0076 0359 0065 0062 0093 0300 Lets draw some conclusions informa tion First seems motors display ks fall roughly three categories conve nience Ill list 1/k categories instead thus 2300 2000 1800 rpm/volt aver age same prop battery higher 1/k higher rpmexcept influence R see below Next no matter what motor k factor clear motors tested needed average about 73 watts input power turn sample prop selected value 9000 rpm same time motors notice ably larger Rs needed input power general can expect shorter and/or slower flights R increases Within given k range motors lowest R clearly developed greatest power turned prop fastest course exactly what expected Equation 3 above ef fect x R term subtracts voltage voltage applied motor terminals ideal work-producing part motor thinks lower voltage being applied what really above data case facts dont seem add up Its case 360 ST motor nominal 1/k 2300 group does have lowest R group still performs better should comparativelyin 60-volt test point clear experimental error perhaps fact motor has fixed off-neutral brush angle explains result will dig further follow up later co lumn Besides Im getting more re quests information about brush angle Finally last piece data flew motors new Skyvolt design Guess what average worked best bench worked best air though some pretty close calls Heres closing thought view above lot information its serious Electric modelers need Nothing given tells us what power level mo tors rated Thats up manufacturer Neither does tell what maximum recom mended operating current should Thats up manufacturer Neither does tell what maximum recommended no-load voltage rpm Thats up manufacturer course modeldom should also have rely columnists information motor k R either things manu facturer should put motor nameplate DONT YOU AGREE Coming future columns meet nouncements extensive prop data can used motor info above performance information new Astro Model 112 Con stant Current Chargerand Please direct comment question SASE please author address given logo area top column Dont send things magazine editorial offices just have forward July 1989 147 BALSA HOT LINE Call 18061 7456394 lOam 6pm cancel Time FOAM CORE FLOATS PLANS AND KITS WE OFFER SELECTION OF FLOAT PLANS AND KITS FOR 4 12 POUND AIRPLANES WITH y HULL DESIGN IN USE SINCE 1972 SEND SASE FOR CATALOG SHEET KIRCHER R/C PRODUCTS [NC 9 SHEFFIELD WAY CLARK NJ 07066 VEND MOUNTS THE VIBRATION KILLER Fail Iu/ pwI tIn, ,,, iOlQtin 25 ngin, Fjl,ituaIlylIti,wIi ,nne munt Oln/cali5atinredulin t 70% M, 86% 640,,t 01 mounting pOre0~~ e~ , Send 51200 ofleok Omny Order PO kit GSA PSOSUCTS P0 BOO 35025 SARASOTA FL 34232 813 307-4250 FL reeidnt cod 72*aI, Ia INFO 8200 Oredited 11111 order 11 Blades New 40 Pack 100 Pack $485 $895 Deliveried Berkeley Trading CoCheek MO PO Box 26 Berkeley Springs WV 25411
Edition: Model Aviation - 1989/07
Page Numbers: 48, 49, 146, 147
ELECTRIC MEET announcements open months column First up Fifteenth Annual Astro Flight Electric Champs scheduled June 17-18 1989 Fairview Regional Park Costa Mesa CA Events include seven-cell Sailplane Old-Timer Unlimited Sailplane OldTimer contest man-on-man mat serious Electric competitor since encompasses limited motor runs thermal dura tion landing scoring details can obtained writing Harbor Soaring Society 1204 Palm Ave Huntington Beach CA 92648 very same dates June 17-18at opposite end countrywill Second Annual Lehigh Valley Electric Fun-Fly Easton PA near Allentown know what first like Im certainly going second meet welcomes Electrics skill levels simple fun events everyone lots prizes both skill luck can get full details contacting Ellis Grumer 321 Aurora St Phillipsburg NJ 08865 telephone 201 859-0969 call Stan Rauktis 215 252-2024 Next have First Annual BCR/CC Elec tric Fly scheduled July 8 Northern Bur lington County Regional High School sponsored Burlington County Radio Control Club New Jersey too will fun-fly affair low-pressure events information con tact Robert Afflerback 123 Harrington Circle Willingboro NJ 08046 telephone 609 8718777 July 8-9 sees two Midwest Electric Fly com petitionstwo individual days worth Satur day Sunday July 8 9 dual meet wherein Saturday activity sponsored Electric Fliers Only club CD Ken Myers can reach him 313 698-4668 Fun events will include Triple Duration Sail plane Most Beautiful Triple Duration Other Best Non-kit Airplane Best Scale Dual Du ration Sundays event hosted Ann Arbor RC Falcons CD non other Elec tric Grand Master himselfDr Keith Shaw can reach Keith 313 973-6309 Sundays events include All-Up/Last-Down Best Scale Most Impressive Best Finish Most Aerobat ic Both meets Ann Arbor area three bucks gets ya day past column has once cluded representative motor/propeller data has found favorable audience serious Electric modelers month Im offering some specially formatted performance formation will particular interest took advice past refer enced Mitch Polings columns November December 1988 Model Builder magazine Mitch detailed some motor mathematics put forth reader Ed Westbrook fill may have access MB columns Im going generalize supplement some goodies presented begin permanent magnet electric mo tor like ones use electromechanical system displays certain predictable opera tional characteristics resulting the way designed built characteristics can described relatively simple approxi mate mathematical relationship reads like VkxRPMIxR1 simple expression V voltage ap Astros new Model 112 Constant Amp Charger L delivers selectable steady current over timed charge cycle toggle switch panel selects size battery pack being charged 1-14 cellsll4-28 cellsa very large range Author Kopski used collection 05-size motors R get table performance characteristics included months column look alikebut certainly dont perform alike latest Electric trainers market Mirage kit produced Carl Goldberg Models L kit includes motor its wiring harness number formed plastic parts enhance planes appearance Unusually rugged wing has leading edge sheeted balsa both top bottom Kopskis new Skyvolt aerobatic design R pictured last month fully covered red white MonoKote Bare-bones structure no internal equipment weighs 13 oz Acrobatic capabilities retained using wide range power systems 48 Model Aviation Radio Conoi Electrics Bob Kopski 25 West End Dr Lansdale PA 19446 plied motor terminals volts motor current amps RPM course prop rpm above easily determined readily familiar entities nearly Elec tric modeler Ill get R minute So whats k constant directly function makeup motor depen dent number poles number turns armature magnetic makeup motor k neither good nor badit just thats design choice effect k tells us rpm ideal motor will turn volt applied Simply put greater voltage greater proportional rpm course ranges k best suited useturning nominal propellers familiar desirable speeds batteries having practical voltage levels Astute readers surely caught subtlety abovethe word ideal Ideal motors would obey simpler equation VkxRPMorRPM V/k2 Equation 2 literally means ideal motor would produce rpm entirely determined applied voltage value kno matter what prop used such case real life nothing ideal thats R Equation 1 enters picture R equivalent total motor resistance made up mostly armature winding resist ance brush resistance Basically R what makes motor slow down under load easily seen again rewriting Equation 1 thus RPM R k 3 Equation 3 tells us ideal RPM given V k reduced motor current times motor resistance Thus larger prop everyone knows causes motor draw current forces motor slow down simply cause draws current thats R also responsible motor getting hot because motor current flows through resistance generates heat propor tional square current times resis tance I-squared R lost power Ie power taken battery available turn propeller Because I-squared can very large number very important R very small YesR real bad guy armature windings heavy wire high-quality brushes good tight contact commutator Continued page 146 Miter Master * Perfect Truss construction * 900 squaring fence * Triangular adjustable fence Price $1095 Product No 122 Miter Sander Sand angle its complement quickly accurately Miter Master solid alder base mounted non-skid pads alder four-way re versible sliding block carries 2 different grits sand paper 503 357-2732 FOURMOST PRODUCTS 4040 24TH AVE FOREST GROVE OR 97116 a2SOMbRtmts tritrO-i Aederson Co ~Pn0daCtS Inn Only certitied checks ,rooey orders accepted Mintmun order 31200 three packages ot 4 Poeerooles 5350 per package $150 shiporne handling CT resdelfO add 75% sales tan Prices subject change notice hEALER IHOWNEES INVITED Fo further ntornalion dealer prcen send SASS Business Card SERMOS0 R/C SNAP CONNECTORS0 Calar Comma Slatn Box 16787 Stamftxti CT 06935203322-6294 IZiBi- Copter Rubber Band Powered Helicopter Flying repuatibilidy seth ceucut ant reitilts Flys FtRWARD & RACK WARD II HOVERS 5 TURNS can enec Fly INVERTED lre nee 3r FEAIIIRES [7 ot0 ~ hcrdunre ocpplied talsa N Paper Ccslralion Deluled step kyofep,sfrnlios euler ports POE-CUT & DRILLED Bald ArrIrone directly cr11 FULL SIZE PLANS icr f.t esycooenbl July 1989 49 Kopskis servo-operated On/Off motor switch assembly simplicity itself Switch servo affixed plywood plate double-sticky servo tape Small balsa loca tor blocks arrows keep units aligned Sticky-back Velcro strips mount assembly Inside fuselage Pushrod fits through hole bored lever Astro microswitch Wheel collar sets operation just right $975AVAILABLE AT AMERICAS$525 FINEST HOBBY SHOPS OI5TRIBUTEO BY SMIflflHI Z1D5U85ZRD 7550 San Gabriel Rend cadere CA 534fl 455-1717 COMPETITION ACCESSORIES & CUSTOMIZED K&B ENGINES RACING WHEELS KLO7Z OIL CARBON FIBER SOLID LINES ALL KINDS OF FUEL TUBING FOUR BRANDS OF GLOW PLUGS HA RD-TO-FIND HA RD WA RE OLD TIMER SUPPLIES COILS CONDENSERS NGK & STIlT SPARK PLUGS SILK 12 COLORS QUALITY DOPE BRUSHES 5& 7LOOP 1/4RUBBER BANDS TRANSISTOR IGNITION SYSTEMS RESISTOR HIGH TENSION LEADS 1/2A TEXACO PLA YBOY SR KIT 1/2A TEXACO ENGINES & PARTS KSB & IGNITION TIMERS RUBBER POWER KITS PROPS TISSUE AND OTHER SUPPLIES CYANOACRYLATES & EPOXIES ORDER BY MAIL OR PHONE 619 728-4365 SORRY NO COD VISA & MASTERCARD WELCOME MINIMUM MERCHANDISE ORDER $1000 SHIPPING & HANDLING FEE $150 FOR INSURANCE ADD $100 STOCK ORDERS SHIPPED WITHIN 24 HRS VTBEGINNER RACES Instructions Club Programs NORTHEAST AREA Information Contact North East Pylon Racing Organization 119 Dean AveFranklin Mass 02033 506 529-4043 401 739-2653 huh information Banzai can get touch Jerry Banzai Enterprises 2997 Anderson Ave Port Alberni BC Can ada V9Y2V3 Instructional videotapes Have ever won dered cut foam cores vacuum-bag wings build fiberglass fuselages Did decide beyond abilities just wasnt worth trouble Better days ahead Channel 1 Productions Humble TX has made three fantastic videotapes available RC modeler Cutting Foam Cores Making Templates Covers step-by-step technique foam wings plans automatic hands-off foam cutter will give sharp trailing edges will given videotape bonus Vacuum Bag Fiberglass Wings Buy MaterialsThe videotape gives simplified step-by-step way build composite wings model Sailplanes Power planes Making Fiberglass MoldsThis videotape gives ABCs making fiberglass molds what equipment material will need technique teaches allows manufac ture fiberglass part What think Now can build allglass Slope Racer have dreaming about simply replace old beaten-up foam wing glass fuselage tapes will cost $3495 plus $350 shipping buy two videotapes can get third $2495 plus shipping information con tact Julian Tamez Channel Productions 19827 Bishops Gate Suite No 1 Humble TX 77328 telephone 713 278-4575 Canards flying wings next column will devoted entirely flying wings ca nards Although configurations may look little different offer outstanding perform ance Slope flier Along general dis cussion theories behind unique type aircraft will taking look few kits available Just name few Jades Telos ca nard new Shogun flying wing Bob Sealys Javelin flying wing Future Flights Klingberg fly ing wing new Annihilator Slope Racer RC Electrics/Kopski Continued page 49 very important last itemthe good tight contact has by-product another loss frictionbut loss generally much less loss associated poor resistive brush con tact OK what good stuff Its going take column fully illustrate answer now have no choice ask patience may wish save col umn becausecombined future ones II eventually have lots useful info know make best use fu ture Electrics meantime well get start future Some motor performance data fill blanks above information follows result testing done substantial sample 05-size motors theres intolerable meaning less nomenclature again Mitch Poling Model Builder issues previously mentioned used limited data previously published through laborious manipulation simultaneous equa tions derived motor k resistance etc Since Im fortunate have direct ways determining constants decided get detailed education myself addition would save everyone else may inter ested lot work provide accurate val ues constants would otherwise de rived calculation What follows some rele vant data nine motors consisting seven dif ferent so-called 05 models will evident 05 motors created equal Now some words about data associ ated calculations motor first run two values low voltage prop thin flat two-bladed nearly no-load stick stead practical purposes real load motor internal friction cannot eliminated stick looked like prop tach permitted direct rpm mea surement subsequent determination kthe volts-per-rpm constant two rpm values applied voltage readings averaged calcu late ks listed below Following motor run same prop Top Flite 8 x 4 wood exactly 60 volts applied measured brush termi nals done see motors haved relative other would case fictitious fixed cell count throttle set ting Motor current rpm recorded motor current applied 60 volts multiplied give listed input power watts As will see data prop rpm motor input power varied widely over range sample motors Following applied voltage read justed rpm exactly 9000 done see motor efficiency varied required same workie turn same prop same rpm As will see data motors required just about same input power requiring power least efficient motors also ones largest Rexactly what would expected cause R associated power loss power taken battery available prop diverted making motor hot instead As motor R determined ap plying constant 100 amp electronically regu lated current through motor armature held stalled resulting voltage drop present motor terminals recorded 10 times dif ferent angular positions stalled armature done because small voltage drop varies bit commutator position high est lowest readings discarded remaining eight readings averaged av erage voltage divided 10-amp current pro duced R values listed Finally since some may wonder digital instru mentation used throughout data gathering data average believed quite good Certainly comparative data very good case must keep mind looks like motors volved absolute sample size model indeed limited general have no way knowing particular motor used typi cal particularly good bad Since have have no choice con sider representative particular product Also please note motors run shown operation minute two no implication presentation particular product will sustain test levels indicated see Heres closing thought below Measured Calculated Motor Performance C Pwr 5/k"R MotorVoltsAmpsRPMwattsrpm/voltohms cobalt 60 250 11260 150 2303 0051 05 ** 456 165900075 Ooid 60 213 10600 128 2298 0057 Fire-I 474 156900074 146 Model Aviation OUR REV-UP VERA GES OVEji 9000 PROPS III IMMEDIATE SHIPMENT ON VISA/MC SPECIALISTS IN CUSTOM COX TEE DEE & REED ENGINES 020S 049S 051S & 09S ALL CUS TOM & STOCK PARTS VAILABLEINDIVIDUALL Y RACE ILIWANNA Q500F-iFAI 1111 iI E7Vi wuu WE ARE SHOOTING DOWN HIGH BALSA PRICES WITH SUPER QUALITY Satisfaction Guaranteed Direct Only BALSA SN LETS 36 48 30 1162 33 3322 40 182 43 3162 49 14 2 66 1323 37 1203 37 1163 37493i 3323 44 58 37 18 3 5471 45 3163- 628265 143 73 9561 6163 85110 36 3 6812471 12 e3110155 34 3165191 1164 -697648 3324 709468 184 60168 86 3164 9312275 14 411013484 38 4165225138 12 4225261 MATCHED SHEETS 42 3324100 164106 3164120 144131 ALU STICKS 3645 1161409 1163810 1161214 3321410 3323812 3321216 181808 18141116 18381218 18121024 3163161116 316381726 316122230 14141624 14381928 14122130 14343444 1414065 5165167128 38382737 38123246 36344255 381570 12123653 12344662 1215878 58584665 34346790 CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa ~-@ LIGHT 4-6 LB BALSATRIANGLES36 WOOD36 1414251323 53 3836 361203 53 121235116353 343445332363 1 1551/8377 316389 BALSA PLANKS36143104 1185383122 12150123158 13200343242 1428013335 1173275116483 11243603324160 22225184115 233263164133 24435144158 33495384238 34688124322 TAPERED SHEETS36 142 65 14385 382 68 38398 123120 LONE STAREPOXY 90Lot 895 5 noo596 iSo,598 30 rrro596 TRAILING EDGE 36 14132 51611439 3811246 12270 7NTGLUE 1 oo Thck298 1, Th,288 2o Thck550 2oz 5,550 BASSWOOD45 31631626 3161430 3163838 3/161246 3163460 141442 143849 43480 38 3660 381270 3/83490 121290 1234100 BUNDLE DEALS 20-116338698 201164361035 20332 865 15332436955 161/8336735 1018436695 15316336925 10-316436835 1014336655 1014 436830 1538336870 538436655 512336540 5124361080 10332448885 518448500 5-3/1 64 0 514448645 * NEW * Hundreds new sizes accessories finishing materials Send #10 SASE lafest catalog SPRUCE STICKS 36 48 18 81725 18 142026 16 382232 3163162838 14 143450 14 3/84055 141/24565 38 384968 38 126077 12126688 1234 75 87 SPRUCE TRIANGLES 36 3838 47 1212 64 3434 81 186 1 8 12 HARD MAPLE 1438 363 8 3812 3834 1234 BIRCH DOWELS 18 316 14 5 16 38 B 40 45 50 58 68 36 09 14 25 32 3PLYBIRCH48 1-6412620 1 3212445 1 1612455 1812495 SPLVBIRCH 332 12 1/812 316 12 1/412 38 12 1212 48, 598 625 626 625 725 900 LITEPLY 48GROG VEDLOMOUNTS 02 IncheS 155383-41840 3153834532-40 123431645 1412495 LONE STAR MODELS Cont46 Handling Charge UPS Add $300 COD *300 extra PP APO FPO 1623 57th St Lubbock TX 79412 Weaccept Visa Mastercard peesonal checks COD 614% tax Texss US currency Minimum Wood Oedar $1000 6Ygp Gold6022310700 Fire-2 483 1549000 HP60389960 00 497 1489000 Hyper- 603398320 rhrsl 6601449000 Kyosho 6023930960 3605T449369000 Thrst- 603649930 fl3dsler 5203399000 Trbo 603609090 530-I 5991549000 Trbo 601519390 550-2 5921459000 Notes listed alphabelically l limed 333 74 308 74 71 95 343 72 98 72 96 92 93 86 2332 2320 3809 2350 2076 2049 2039 0060 0076 0359 0065 0062 0093 0300 Lets draw some conclusions informa tion First seems motors display ks fall roughly three categories conve nience Ill list 1/k categories instead thus 2300 2000 1800 rpm/volt aver age same prop battery higher 1/k higher rpmexcept influence R see below Next no matter what motor k factor clear motors tested needed average about 73 watts input power turn sample prop selected value 9000 rpm same time motors notice ably larger Rs needed input power general can expect shorter and/or slower flights R increases Within given k range motors lowest R clearly developed greatest power turned prop fastest course exactly what expected Equation 3 above ef fect x R term subtracts voltage voltage applied motor terminals ideal work-producing part motor thinks lower voltage being applied what really above data case facts dont seem add up Its case 360 ST motor nominal 1/k 2300 group does have lowest R group still performs better should comparativelyin 60-volt test point clear experimental error perhaps fact motor has fixed off-neutral brush angle explains result will dig further follow up later co lumn Besides Im getting more re quests information about brush angle Finally last piece data flew motors new Skyvolt design Guess what average worked best bench worked best air though some pretty close calls Heres closing thought view above lot information its serious Electric modelers need Nothing given tells us what power level mo tors rated Thats up manufacturer Neither does tell what maximum recom mended operating current should Thats up manufacturer Neither does tell what maximum recommended no-load voltage rpm Thats up manufacturer course modeldom should also have rely columnists information motor k R either things manu facturer should put motor nameplate DONT YOU AGREE Coming future columns meet nouncements extensive prop data can used motor info above performance information new Astro Model 112 Con stant Current Chargerand Please direct comment question SASE please author address given logo area top column Dont send things magazine editorial offices just have forward July 1989 147 BALSA HOT LINE Call 18061 7456394 lOam 6pm cancel Time FOAM CORE FLOATS PLANS AND KITS WE OFFER SELECTION OF FLOAT PLANS AND KITS FOR 4 12 POUND AIRPLANES WITH y HULL DESIGN IN USE SINCE 1972 SEND SASE FOR CATALOG SHEET KIRCHER R/C PRODUCTS [NC 9 SHEFFIELD WAY CLARK NJ 07066 VEND MOUNTS THE VIBRATION KILLER Fail Iu/ pwI tIn, ,,, iOlQtin 25 ngin, Fjl,ituaIlylIti,wIi ,nne munt Oln/cali5atinredulin t 70% M, 86% 640,,t 01 mounting pOre0~~ e~ , Send 51200 ofleok Omny Order PO kit GSA PSOSUCTS P0 BOO 35025 SARASOTA FL 34232 813 307-4250 FL reeidnt cod 72*aI, Ia INFO 8200 Oredited 11111 order 11 Blades New 40 Pack 100 Pack $485 $895 Deliveried Berkeley Trading CoCheek MO PO Box 26 Berkeley Springs WV 25411
Edition: Model Aviation - 1989/07
Page Numbers: 48, 49, 146, 147
ELECTRIC MEET announcements open months column First up Fifteenth Annual Astro Flight Electric Champs scheduled June 17-18 1989 Fairview Regional Park Costa Mesa CA Events include seven-cell Sailplane Old-Timer Unlimited Sailplane OldTimer contest man-on-man mat serious Electric competitor since encompasses limited motor runs thermal dura tion landing scoring details can obtained writing Harbor Soaring Society 1204 Palm Ave Huntington Beach CA 92648 very same dates June 17-18at opposite end countrywill Second Annual Lehigh Valley Electric Fun-Fly Easton PA near Allentown know what first like Im certainly going second meet welcomes Electrics skill levels simple fun events everyone lots prizes both skill luck can get full details contacting Ellis Grumer 321 Aurora St Phillipsburg NJ 08865 telephone 201 859-0969 call Stan Rauktis 215 252-2024 Next have First Annual BCR/CC Elec tric Fly scheduled July 8 Northern Bur lington County Regional High School sponsored Burlington County Radio Control Club New Jersey too will fun-fly affair low-pressure events information con tact Robert Afflerback 123 Harrington Circle Willingboro NJ 08046 telephone 609 8718777 July 8-9 sees two Midwest Electric Fly com petitionstwo individual days worth Satur day Sunday July 8 9 dual meet wherein Saturday activity sponsored Electric Fliers Only club CD Ken Myers can reach him 313 698-4668 Fun events will include Triple Duration Sail plane Most Beautiful Triple Duration Other Best Non-kit Airplane Best Scale Dual Du ration Sundays event hosted Ann Arbor RC Falcons CD non other Elec tric Grand Master himselfDr Keith Shaw can reach Keith 313 973-6309 Sundays events include All-Up/Last-Down Best Scale Most Impressive Best Finish Most Aerobat ic Both meets Ann Arbor area three bucks gets ya day past column has once cluded representative motor/propeller data has found favorable audience serious Electric modelers month Im offering some specially formatted performance formation will particular interest took advice past refer enced Mitch Polings columns November December 1988 Model Builder magazine Mitch detailed some motor mathematics put forth reader Ed Westbrook fill may have access MB columns Im going generalize supplement some goodies presented begin permanent magnet electric mo tor like ones use electromechanical system displays certain predictable opera tional characteristics resulting the way designed built characteristics can described relatively simple approxi mate mathematical relationship reads like VkxRPMIxR1 simple expression V voltage ap Astros new Model 112 Constant Amp Charger L delivers selectable steady current over timed charge cycle toggle switch panel selects size battery pack being charged 1-14 cellsll4-28 cellsa very large range Author Kopski used collection 05-size motors R get table performance characteristics included months column look alikebut certainly dont perform alike latest Electric trainers market Mirage kit produced Carl Goldberg Models L kit includes motor its wiring harness number formed plastic parts enhance planes appearance Unusually rugged wing has leading edge sheeted balsa both top bottom Kopskis new Skyvolt aerobatic design R pictured last month fully covered red white MonoKote Bare-bones structure no internal equipment weighs 13 oz Acrobatic capabilities retained using wide range power systems 48 Model Aviation Radio Conoi Electrics Bob Kopski 25 West End Dr Lansdale PA 19446 plied motor terminals volts motor current amps RPM course prop rpm above easily determined readily familiar entities nearly Elec tric modeler Ill get R minute So whats k constant directly function makeup motor depen dent number poles number turns armature magnetic makeup motor k neither good nor badit just thats design choice effect k tells us rpm ideal motor will turn volt applied Simply put greater voltage greater proportional rpm course ranges k best suited useturning nominal propellers familiar desirable speeds batteries having practical voltage levels Astute readers surely caught subtlety abovethe word ideal Ideal motors would obey simpler equation VkxRPMorRPM V/k2 Equation 2 literally means ideal motor would produce rpm entirely determined applied voltage value kno matter what prop used such case real life nothing ideal thats R Equation 1 enters picture R equivalent total motor resistance made up mostly armature winding resist ance brush resistance Basically R what makes motor slow down under load easily seen again rewriting Equation 1 thus RPM R k 3 Equation 3 tells us ideal RPM given V k reduced motor current times motor resistance Thus larger prop everyone knows causes motor draw current forces motor slow down simply cause draws current thats R also responsible motor getting hot because motor current flows through resistance generates heat propor tional square current times resis tance I-squared R lost power Ie power taken battery available turn propeller Because I-squared can very large number very important R very small YesR real bad guy armature windings heavy wire high-quality brushes good tight contact commutator Continued page 146 Miter Master * Perfect Truss construction * 900 squaring fence * Triangular adjustable fence Price $1095 Product No 122 Miter Sander Sand angle its complement quickly accurately Miter Master solid alder base mounted non-skid pads alder four-way re versible sliding block carries 2 different grits sand paper 503 357-2732 FOURMOST PRODUCTS 4040 24TH AVE FOREST GROVE OR 97116 a2SOMbRtmts tritrO-i Aederson Co ~Pn0daCtS Inn Only certitied checks ,rooey orders accepted Mintmun order 31200 three packages ot 4 Poeerooles 5350 per package $150 shiporne handling CT resdelfO add 75% sales tan Prices subject change notice hEALER IHOWNEES INVITED Fo further ntornalion dealer prcen send SASS Business Card SERMOS0 R/C SNAP CONNECTORS0 Calar Comma Slatn Box 16787 Stamftxti CT 06935203322-6294 IZiBi- Copter Rubber Band Powered Helicopter Flying repuatibilidy seth ceucut ant reitilts Flys FtRWARD & RACK WARD II HOVERS 5 TURNS can enec Fly INVERTED lre nee 3r FEAIIIRES [7 ot0 ~ hcrdunre ocpplied talsa N Paper Ccslralion Deluled step kyofep,sfrnlios euler ports POE-CUT & DRILLED Bald ArrIrone directly cr11 FULL SIZE PLANS icr f.t esycooenbl July 1989 49 Kopskis servo-operated On/Off motor switch assembly simplicity itself Switch servo affixed plywood plate double-sticky servo tape Small balsa loca tor blocks arrows keep units aligned Sticky-back Velcro strips mount assembly Inside fuselage Pushrod fits through hole bored lever Astro microswitch Wheel collar sets operation just right $975AVAILABLE AT AMERICAS$525 FINEST HOBBY SHOPS OI5TRIBUTEO BY SMIflflHI Z1D5U85ZRD 7550 San Gabriel Rend cadere CA 534fl 455-1717 COMPETITION ACCESSORIES & CUSTOMIZED K&B ENGINES RACING WHEELS KLO7Z OIL CARBON FIBER SOLID LINES ALL KINDS OF FUEL TUBING FOUR BRANDS OF GLOW PLUGS HA RD-TO-FIND HA RD WA RE OLD TIMER SUPPLIES COILS CONDENSERS NGK & STIlT SPARK PLUGS SILK 12 COLORS QUALITY DOPE BRUSHES 5& 7LOOP 1/4RUBBER BANDS TRANSISTOR IGNITION SYSTEMS RESISTOR HIGH TENSION LEADS 1/2A TEXACO PLA YBOY SR KIT 1/2A TEXACO ENGINES & PARTS KSB & IGNITION TIMERS RUBBER POWER KITS PROPS TISSUE AND OTHER SUPPLIES CYANOACRYLATES & EPOXIES ORDER BY MAIL OR PHONE 619 728-4365 SORRY NO COD VISA & MASTERCARD WELCOME MINIMUM MERCHANDISE ORDER $1000 SHIPPING & HANDLING FEE $150 FOR INSURANCE ADD $100 STOCK ORDERS SHIPPED WITHIN 24 HRS VTBEGINNER RACES Instructions Club Programs NORTHEAST AREA Information Contact North East Pylon Racing Organization 119 Dean AveFranklin Mass 02033 506 529-4043 401 739-2653 huh information Banzai can get touch Jerry Banzai Enterprises 2997 Anderson Ave Port Alberni BC Can ada V9Y2V3 Instructional videotapes Have ever won dered cut foam cores vacuum-bag wings build fiberglass fuselages Did decide beyond abilities just wasnt worth trouble Better days ahead Channel 1 Productions Humble TX has made three fantastic videotapes available RC modeler Cutting Foam Cores Making Templates Covers step-by-step technique foam wings plans automatic hands-off foam cutter will give sharp trailing edges will given videotape bonus Vacuum Bag Fiberglass Wings Buy MaterialsThe videotape gives simplified step-by-step way build composite wings model Sailplanes Power planes Making Fiberglass MoldsThis videotape gives ABCs making fiberglass molds what equipment material will need technique teaches allows manufac ture fiberglass part What think Now can build allglass Slope Racer have dreaming about simply replace old beaten-up foam wing glass fuselage tapes will cost $3495 plus $350 shipping buy two videotapes can get third $2495 plus shipping information con tact Julian Tamez Channel Productions 19827 Bishops Gate Suite No 1 Humble TX 77328 telephone 713 278-4575 Canards flying wings next column will devoted entirely flying wings ca nards Although configurations may look little different offer outstanding perform ance Slope flier Along general dis cussion theories behind unique type aircraft will taking look few kits available Just name few Jades Telos ca nard new Shogun flying wing Bob Sealys Javelin flying wing Future Flights Klingberg fly ing wing new Annihilator Slope Racer RC Electrics/Kopski Continued page 49 very important last itemthe good tight contact has by-product another loss frictionbut loss generally much less loss associated poor resistive brush con tact OK what good stuff Its going take column fully illustrate answer now have no choice ask patience may wish save col umn becausecombined future ones II eventually have lots useful info know make best use fu ture Electrics meantime well get start future Some motor performance data fill blanks above information follows result testing done substantial sample 05-size motors theres intolerable meaning less nomenclature again Mitch Poling Model Builder issues previously mentioned used limited data previously published through laborious manipulation simultaneous equa tions derived motor k resistance etc Since Im fortunate have direct ways determining constants decided get detailed education myself addition would save everyone else may inter ested lot work provide accurate val ues constants would otherwise de rived calculation What follows some rele vant data nine motors consisting seven dif ferent so-called 05 models will evident 05 motors created equal Now some words about data associ ated calculations motor first run two values low voltage prop thin flat two-bladed nearly no-load stick stead practical purposes real load motor internal friction cannot eliminated stick looked like prop tach permitted direct rpm mea surement subsequent determination kthe volts-per-rpm constant two rpm values applied voltage readings averaged calcu late ks listed below Following motor run same prop Top Flite 8 x 4 wood exactly 60 volts applied measured brush termi nals done see motors haved relative other would case fictitious fixed cell count throttle set ting Motor current rpm recorded motor current applied 60 volts multiplied give listed input power watts As will see data prop rpm motor input power varied widely over range sample motors Following applied voltage read justed rpm exactly 9000 done see motor efficiency varied required same workie turn same prop same rpm As will see data motors required just about same input power requiring power least efficient motors also ones largest Rexactly what would expected cause R associated power loss power taken battery available prop diverted making motor hot instead As motor R determined ap plying constant 100 amp electronically regu lated current through motor armature held stalled resulting voltage drop present motor terminals recorded 10 times dif ferent angular positions stalled armature done because small voltage drop varies bit commutator position high est lowest readings discarded remaining eight readings averaged av erage voltage divided 10-amp current pro duced R values listed Finally since some may wonder digital instru mentation used throughout data gathering data average believed quite good Certainly comparative data very good case must keep mind looks like motors volved absolute sample size model indeed limited general have no way knowing particular motor used typi cal particularly good bad Since have have no choice con sider representative particular product Also please note motors run shown operation minute two no implication presentation particular product will sustain test levels indicated see Heres closing thought below Measured Calculated Motor Performance C Pwr 5/k"R MotorVoltsAmpsRPMwattsrpm/voltohms cobalt 60 250 11260 150 2303 0051 05 ** 456 165900075 Ooid 60 213 10600 128 2298 0057 Fire-I 474 156900074 146 Model Aviation OUR REV-UP VERA GES OVEji 9000 PROPS III IMMEDIATE SHIPMENT ON VISA/MC SPECIALISTS IN CUSTOM COX TEE DEE & REED ENGINES 020S 049S 051S & 09S ALL CUS TOM & STOCK PARTS VAILABLEINDIVIDUALL Y RACE ILIWANNA Q500F-iFAI 1111 iI E7Vi wuu WE ARE SHOOTING DOWN HIGH BALSA PRICES WITH SUPER QUALITY Satisfaction Guaranteed Direct Only BALSA SN LETS 36 48 30 1162 33 3322 40 182 43 3162 49 14 2 66 1323 37 1203 37 1163 37493i 3323 44 58 37 18 3 5471 45 3163- 628265 143 73 9561 6163 85110 36 3 6812471 12 e3110155 34 3165191 1164 -697648 3324 709468 184 60168 86 3164 9312275 14 411013484 38 4165225138 12 4225261 MATCHED SHEETS 42 3324100 164106 3164120 144131 ALU STICKS 3645 1161409 1163810 1161214 3321410 3323812 3321216 181808 18141116 18381218 18121024 3163161116 316381726 316122230 14141624 14381928 14122130 14343444 1414065 5165167128 38382737 38123246 36344255 381570 12123653 12344662 1215878 58584665 34346790 CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa ~-@ LIGHT 4-6 LB BALSATRIANGLES36 WOOD36 1414251323 53 3836 361203 53 121235116353 343445332363 1 1551/8377 316389 BALSA PLANKS36143104 1185383122 12150123158 13200343242 1428013335 1173275116483 11243603324160 22225184115 233263164133 24435144158 33495384238 34688124322 TAPERED SHEETS36 142 65 14385 382 68 38398 123120 LONE STAREPOXY 90Lot 895 5 noo596 iSo,598 30 rrro596 TRAILING EDGE 36 14132 51611439 3811246 12270 7NTGLUE 1 oo Thck298 1, Th,288 2o Thck550 2oz 5,550 BASSWOOD45 31631626 3161430 3163838 3/161246 3163460 141442 143849 43480 38 3660 381270 3/83490 121290 1234100 BUNDLE DEALS 20-116338698 201164361035 20332 865 15332436955 161/8336735 1018436695 15316336925 10-316436835 1014336655 1014 436830 1538336870 538436655 512336540 5124361080 10332448885 518448500 5-3/1 64 0 514448645 * NEW * Hundreds new sizes accessories finishing materials Send #10 SASE lafest catalog SPRUCE STICKS 36 48 18 81725 18 142026 16 382232 3163162838 14 143450 14 3/84055 141/24565 38 384968 38 126077 12126688 1234 75 87 SPRUCE TRIANGLES 36 3838 47 1212 64 3434 81 186 1 8 12 HARD MAPLE 1438 363 8 3812 3834 1234 BIRCH DOWELS 18 316 14 5 16 38 B 40 45 50 58 68 36 09 14 25 32 3PLYBIRCH48 1-6412620 1 3212445 1 1612455 1812495 SPLVBIRCH 332 12 1/812 316 12 1/412 38 12 1212 48, 598 625 626 625 725 900 LITEPLY 48GROG VEDLOMOUNTS 02 IncheS 155383-41840 3153834532-40 123431645 1412495 LONE STAR MODELS Cont46 Handling Charge UPS Add $300 COD *300 extra PP APO FPO 1623 57th St Lubbock TX 79412 Weaccept Visa Mastercard peesonal checks COD 614% tax Texss US currency Minimum Wood Oedar $1000 6Ygp Gold6022310700 Fire-2 483 1549000 HP60389960 00 497 1489000 Hyper- 603398320 rhrsl 6601449000 Kyosho 6023930960 3605T449369000 Thrst- 603649930 fl3dsler 5203399000 Trbo 603609090 530-I 5991549000 Trbo 601519390 550-2 5921459000 Notes listed alphabelically l limed 333 74 308 74 71 95 343 72 98 72 96 92 93 86 2332 2320 3809 2350 2076 2049 2039 0060 0076 0359 0065 0062 0093 0300 Lets draw some conclusions informa tion First seems motors display ks fall roughly three categories conve nience Ill list 1/k categories instead thus 2300 2000 1800 rpm/volt aver age same prop battery higher 1/k higher rpmexcept influence R see below Next no matter what motor k factor clear motors tested needed average about 73 watts input power turn sample prop selected value 9000 rpm same time motors notice ably larger Rs needed input power general can expect shorter and/or slower flights R increases Within given k range motors lowest R clearly developed greatest power turned prop fastest course exactly what expected Equation 3 above ef fect x R term subtracts voltage voltage applied motor terminals ideal work-producing part motor thinks lower voltage being applied what really above data case facts dont seem add up Its case 360 ST motor nominal 1/k 2300 group does have lowest R group still performs better should comparativelyin 60-volt test point clear experimental error perhaps fact motor has fixed off-neutral brush angle explains result will dig further follow up later co lumn Besides Im getting more re quests information about brush angle Finally last piece data flew motors new Skyvolt design Guess what average worked best bench worked best air though some pretty close calls Heres closing thought view above lot information its serious Electric modelers need Nothing given tells us what power level mo tors rated Thats up manufacturer Neither does tell what maximum recom mended operating current should Thats up manufacturer Neither does tell what maximum recommended no-load voltage rpm Thats up manufacturer course modeldom should also have rely columnists information motor k R either things manu facturer should put motor nameplate DONT YOU AGREE Coming future columns meet nouncements extensive prop data can used motor info above performance information new Astro Model 112 Con stant Current Chargerand Please direct comment question SASE please author address given logo area top column Dont send things magazine editorial offices just have forward July 1989 147 BALSA HOT LINE Call 18061 7456394 lOam 6pm cancel Time FOAM CORE FLOATS PLANS AND KITS WE OFFER SELECTION OF FLOAT PLANS AND KITS FOR 4 12 POUND AIRPLANES WITH y HULL DESIGN IN USE SINCE 1972 SEND SASE FOR CATALOG SHEET KIRCHER R/C PRODUCTS [NC 9 SHEFFIELD WAY CLARK NJ 07066 VEND MOUNTS THE VIBRATION KILLER Fail Iu/ pwI tIn, ,,, iOlQtin 25 ngin, Fjl,ituaIlylIti,wIi ,nne munt Oln/cali5atinredulin t 70% M, 86% 640,,t 01 mounting pOre0~~ e~ , Send 51200 ofleok Omny Order PO kit GSA PSOSUCTS P0 BOO 35025 SARASOTA FL 34232 813 307-4250 FL reeidnt cod 72*aI, Ia INFO 8200 Oredited 11111 order 11 Blades New 40 Pack 100 Pack $485 $895 Deliveried Berkeley Trading CoCheek MO PO Box 26 Berkeley Springs WV 25411
Edition: Model Aviation - 1989/07
Page Numbers: 48, 49, 146, 147
ELECTRIC MEET announcements open months column First up Fifteenth Annual Astro Flight Electric Champs scheduled June 17-18 1989 Fairview Regional Park Costa Mesa CA Events include seven-cell Sailplane Old-Timer Unlimited Sailplane OldTimer contest man-on-man mat serious Electric competitor since encompasses limited motor runs thermal dura tion landing scoring details can obtained writing Harbor Soaring Society 1204 Palm Ave Huntington Beach CA 92648 very same dates June 17-18at opposite end countrywill Second Annual Lehigh Valley Electric Fun-Fly Easton PA near Allentown know what first like Im certainly going second meet welcomes Electrics skill levels simple fun events everyone lots prizes both skill luck can get full details contacting Ellis Grumer 321 Aurora St Phillipsburg NJ 08865 telephone 201 859-0969 call Stan Rauktis 215 252-2024 Next have First Annual BCR/CC Elec tric Fly scheduled July 8 Northern Bur lington County Regional High School sponsored Burlington County Radio Control Club New Jersey too will fun-fly affair low-pressure events information con tact Robert Afflerback 123 Harrington Circle Willingboro NJ 08046 telephone 609 8718777 July 8-9 sees two Midwest Electric Fly com petitionstwo individual days worth Satur day Sunday July 8 9 dual meet wherein Saturday activity sponsored Electric Fliers Only club CD Ken Myers can reach him 313 698-4668 Fun events will include Triple Duration Sail plane Most Beautiful Triple Duration Other Best Non-kit Airplane Best Scale Dual Du ration Sundays event hosted Ann Arbor RC Falcons CD non other Elec tric Grand Master himselfDr Keith Shaw can reach Keith 313 973-6309 Sundays events include All-Up/Last-Down Best Scale Most Impressive Best Finish Most Aerobat ic Both meets Ann Arbor area three bucks gets ya day past column has once cluded representative motor/propeller data has found favorable audience serious Electric modelers month Im offering some specially formatted performance formation will particular interest took advice past refer enced Mitch Polings columns November December 1988 Model Builder magazine Mitch detailed some motor mathematics put forth reader Ed Westbrook fill may have access MB columns Im going generalize supplement some goodies presented begin permanent magnet electric mo tor like ones use electromechanical system displays certain predictable opera tional characteristics resulting the way designed built characteristics can described relatively simple approxi mate mathematical relationship reads like VkxRPMIxR1 simple expression V voltage ap Astros new Model 112 Constant Amp Charger L delivers selectable steady current over timed charge cycle toggle switch panel selects size battery pack being charged 1-14 cellsll4-28 cellsa very large range Author Kopski used collection 05-size motors R get table performance characteristics included months column look alikebut certainly dont perform alike latest Electric trainers market Mirage kit produced Carl Goldberg Models L kit includes motor its wiring harness number formed plastic parts enhance planes appearance Unusually rugged wing has leading edge sheeted balsa both top bottom Kopskis new Skyvolt aerobatic design R pictured last month fully covered red white MonoKote Bare-bones structure no internal equipment weighs 13 oz Acrobatic capabilities retained using wide range power systems 48 Model Aviation Radio Conoi Electrics Bob Kopski 25 West End Dr Lansdale PA 19446 plied motor terminals volts motor current amps RPM course prop rpm above easily determined readily familiar entities nearly Elec tric modeler Ill get R minute So whats k constant directly function makeup motor depen dent number poles number turns armature magnetic makeup motor k neither good nor badit just thats design choice effect k tells us rpm ideal motor will turn volt applied Simply put greater voltage greater proportional rpm course ranges k best suited useturning nominal propellers familiar desirable speeds batteries having practical voltage levels Astute readers surely caught subtlety abovethe word ideal Ideal motors would obey simpler equation VkxRPMorRPM V/k2 Equation 2 literally means ideal motor would produce rpm entirely determined applied voltage value kno matter what prop used such case real life nothing ideal thats R Equation 1 enters picture R equivalent total motor resistance made up mostly armature winding resist ance brush resistance Basically R what makes motor slow down under load easily seen again rewriting Equation 1 thus RPM R k 3 Equation 3 tells us ideal RPM given V k reduced motor current times motor resistance Thus larger prop everyone knows causes motor draw current forces motor slow down simply cause draws current thats R also responsible motor getting hot because motor current flows through resistance generates heat propor tional square current times resis tance I-squared R lost power Ie power taken battery available turn propeller Because I-squared can very large number very important R very small YesR real bad guy armature windings heavy wire high-quality brushes good tight contact commutator Continued page 146 Miter Master * Perfect Truss construction * 900 squaring fence * Triangular adjustable fence Price $1095 Product No 122 Miter Sander Sand angle its complement quickly accurately Miter Master solid alder base mounted non-skid pads alder four-way re versible sliding block carries 2 different grits sand paper 503 357-2732 FOURMOST PRODUCTS 4040 24TH AVE FOREST GROVE OR 97116 a2SOMbRtmts tritrO-i Aederson Co ~Pn0daCtS Inn Only certitied checks ,rooey orders accepted Mintmun order 31200 three packages ot 4 Poeerooles 5350 per package $150 shiporne handling CT resdelfO add 75% sales tan Prices subject change notice hEALER IHOWNEES INVITED Fo further ntornalion dealer prcen send SASS Business Card SERMOS0 R/C SNAP CONNECTORS0 Calar Comma Slatn Box 16787 Stamftxti CT 06935203322-6294 IZiBi- Copter Rubber Band Powered Helicopter Flying repuatibilidy seth ceucut ant reitilts Flys FtRWARD & RACK WARD II HOVERS 5 TURNS can enec Fly INVERTED lre nee 3r FEAIIIRES [7 ot0 ~ hcrdunre ocpplied talsa N Paper Ccslralion Deluled step kyofep,sfrnlios euler ports POE-CUT & DRILLED Bald ArrIrone directly cr11 FULL SIZE PLANS icr f.t esycooenbl July 1989 49 Kopskis servo-operated On/Off motor switch assembly simplicity itself Switch servo affixed plywood plate double-sticky servo tape Small balsa loca tor blocks arrows keep units aligned Sticky-back Velcro strips mount assembly Inside fuselage Pushrod fits through hole bored lever Astro microswitch Wheel collar sets operation just right $975AVAILABLE AT AMERICAS$525 FINEST HOBBY SHOPS OI5TRIBUTEO BY SMIflflHI Z1D5U85ZRD 7550 San Gabriel Rend cadere CA 534fl 455-1717 COMPETITION ACCESSORIES & CUSTOMIZED K&B ENGINES RACING WHEELS KLO7Z OIL CARBON FIBER SOLID LINES ALL KINDS OF FUEL TUBING FOUR BRANDS OF GLOW PLUGS HA RD-TO-FIND HA RD WA RE OLD TIMER SUPPLIES COILS CONDENSERS NGK & STIlT SPARK PLUGS SILK 12 COLORS QUALITY DOPE BRUSHES 5& 7LOOP 1/4RUBBER BANDS TRANSISTOR IGNITION SYSTEMS RESISTOR HIGH TENSION LEADS 1/2A TEXACO PLA YBOY SR KIT 1/2A TEXACO ENGINES & PARTS KSB & IGNITION TIMERS RUBBER POWER KITS PROPS TISSUE AND OTHER SUPPLIES CYANOACRYLATES & EPOXIES ORDER BY MAIL OR PHONE 619 728-4365 SORRY NO COD VISA & MASTERCARD WELCOME MINIMUM MERCHANDISE ORDER $1000 SHIPPING & HANDLING FEE $150 FOR INSURANCE ADD $100 STOCK ORDERS SHIPPED WITHIN 24 HRS VTBEGINNER RACES Instructions Club Programs NORTHEAST AREA Information Contact North East Pylon Racing Organization 119 Dean AveFranklin Mass 02033 506 529-4043 401 739-2653 huh information Banzai can get touch Jerry Banzai Enterprises 2997 Anderson Ave Port Alberni BC Can ada V9Y2V3 Instructional videotapes Have ever won dered cut foam cores vacuum-bag wings build fiberglass fuselages Did decide beyond abilities just wasnt worth trouble Better days ahead Channel 1 Productions Humble TX has made three fantastic videotapes available RC modeler Cutting Foam Cores Making Templates Covers step-by-step technique foam wings plans automatic hands-off foam cutter will give sharp trailing edges will given videotape bonus Vacuum Bag Fiberglass Wings Buy MaterialsThe videotape gives simplified step-by-step way build composite wings model Sailplanes Power planes Making Fiberglass MoldsThis videotape gives ABCs making fiberglass molds what equipment material will need technique teaches allows manufac ture fiberglass part What think Now can build allglass Slope Racer have dreaming about simply replace old beaten-up foam wing glass fuselage tapes will cost $3495 plus $350 shipping buy two videotapes can get third $2495 plus shipping information con tact Julian Tamez Channel Productions 19827 Bishops Gate Suite No 1 Humble TX 77328 telephone 713 278-4575 Canards flying wings next column will devoted entirely flying wings ca nards Although configurations may look little different offer outstanding perform ance Slope flier Along general dis cussion theories behind unique type aircraft will taking look few kits available Just name few Jades Telos ca nard new Shogun flying wing Bob Sealys Javelin flying wing Future Flights Klingberg fly ing wing new Annihilator Slope Racer RC Electrics/Kopski Continued page 49 very important last itemthe good tight contact has by-product another loss frictionbut loss generally much less loss associated poor resistive brush con tact OK what good stuff Its going take column fully illustrate answer now have no choice ask patience may wish save col umn becausecombined future ones II eventually have lots useful info know make best use fu ture Electrics meantime well get start future Some motor performance data fill blanks above information follows result testing done substantial sample 05-size motors theres intolerable meaning less nomenclature again Mitch Poling Model Builder issues previously mentioned used limited data previously published through laborious manipulation simultaneous equa tions derived motor k resistance etc Since Im fortunate have direct ways determining constants decided get detailed education myself addition would save everyone else may inter ested lot work provide accurate val ues constants would otherwise de rived calculation What follows some rele vant data nine motors consisting seven dif ferent so-called 05 models will evident 05 motors created equal Now some words about data associ ated calculations motor first run two values low voltage prop thin flat two-bladed nearly no-load stick stead practical purposes real load motor internal friction cannot eliminated stick looked like prop tach permitted direct rpm mea surement subsequent determination kthe volts-per-rpm constant two rpm values applied voltage readings averaged calcu late ks listed below Following motor run same prop Top Flite 8 x 4 wood exactly 60 volts applied measured brush termi nals done see motors haved relative other would case fictitious fixed cell count throttle set ting Motor current rpm recorded motor current applied 60 volts multiplied give listed input power watts As will see data prop rpm motor input power varied widely over range sample motors Following applied voltage read justed rpm exactly 9000 done see motor efficiency varied required same workie turn same prop same rpm As will see data motors required just about same input power requiring power least efficient motors also ones largest Rexactly what would expected cause R associated power loss power taken battery available prop diverted making motor hot instead As motor R determined ap plying constant 100 amp electronically regu lated current through motor armature held stalled resulting voltage drop present motor terminals recorded 10 times dif ferent angular positions stalled armature done because small voltage drop varies bit commutator position high est lowest readings discarded remaining eight readings averaged av erage voltage divided 10-amp current pro duced R values listed Finally since some may wonder digital instru mentation used throughout data gathering data average believed quite good Certainly comparative data very good case must keep mind looks like motors volved absolute sample size model indeed limited general have no way knowing particular motor used typi cal particularly good bad Since have have no choice con sider representative particular product Also please note motors run shown operation minute two no implication presentation particular product will sustain test levels indicated see Heres closing thought below Measured Calculated Motor Performance C Pwr 5/k"R MotorVoltsAmpsRPMwattsrpm/voltohms cobalt 60 250 11260 150 2303 0051 05 ** 456 165900075 Ooid 60 213 10600 128 2298 0057 Fire-I 474 156900074 146 Model Aviation OUR REV-UP VERA GES OVEji 9000 PROPS III IMMEDIATE SHIPMENT ON VISA/MC SPECIALISTS IN CUSTOM COX TEE DEE & REED ENGINES 020S 049S 051S & 09S ALL CUS TOM & STOCK PARTS VAILABLEINDIVIDUALL Y RACE ILIWANNA Q500F-iFAI 1111 iI E7Vi wuu WE ARE SHOOTING DOWN HIGH BALSA PRICES WITH SUPER QUALITY Satisfaction Guaranteed Direct Only BALSA SN LETS 36 48 30 1162 33 3322 40 182 43 3162 49 14 2 66 1323 37 1203 37 1163 37493i 3323 44 58 37 18 3 5471 45 3163- 628265 143 73 9561 6163 85110 36 3 6812471 12 e3110155 34 3165191 1164 -697648 3324 709468 184 60168 86 3164 9312275 14 411013484 38 4165225138 12 4225261 MATCHED SHEETS 42 3324100 164106 3164120 144131 ALU STICKS 3645 1161409 1163810 1161214 3321410 3323812 3321216 181808 18141116 18381218 18121024 3163161116 316381726 316122230 14141624 14381928 14122130 14343444 1414065 5165167128 38382737 38123246 36344255 381570 12123653 12344662 1215878 58584665 34346790 CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa ~-@ LIGHT 4-6 LB BALSATRIANGLES36 WOOD36 1414251323 53 3836 361203 53 121235116353 343445332363 1 1551/8377 316389 BALSA PLANKS36143104 1185383122 12150123158 13200343242 1428013335 1173275116483 11243603324160 22225184115 233263164133 24435144158 33495384238 34688124322 TAPERED SHEETS36 142 65 14385 382 68 38398 123120 LONE STAREPOXY 90Lot 895 5 noo596 iSo,598 30 rrro596 TRAILING EDGE 36 14132 51611439 3811246 12270 7NTGLUE 1 oo Thck298 1, Th,288 2o Thck550 2oz 5,550 BASSWOOD45 31631626 3161430 3163838 3/161246 3163460 141442 143849 43480 38 3660 381270 3/83490 121290 1234100 BUNDLE DEALS 20-116338698 201164361035 20332 865 15332436955 161/8336735 1018436695 15316336925 10-316436835 1014336655 1014 436830 1538336870 538436655 512336540 5124361080 10332448885 518448500 5-3/1 64 0 514448645 * NEW * Hundreds new sizes accessories finishing materials Send #10 SASE lafest catalog SPRUCE STICKS 36 48 18 81725 18 142026 16 382232 3163162838 14 143450 14 3/84055 141/24565 38 384968 38 126077 12126688 1234 75 87 SPRUCE TRIANGLES 36 3838 47 1212 64 3434 81 186 1 8 12 HARD MAPLE 1438 363 8 3812 3834 1234 BIRCH DOWELS 18 316 14 5 16 38 B 40 45 50 58 68 36 09 14 25 32 3PLYBIRCH48 1-6412620 1 3212445 1 1612455 1812495 SPLVBIRCH 332 12 1/812 316 12 1/412 38 12 1212 48, 598 625 626 625 725 900 LITEPLY 48GROG VEDLOMOUNTS 02 IncheS 155383-41840 3153834532-40 123431645 1412495 LONE STAR MODELS Cont46 Handling Charge UPS Add $300 COD *300 extra PP APO FPO 1623 57th St Lubbock TX 79412 Weaccept Visa Mastercard peesonal checks COD 614% tax Texss US currency Minimum Wood Oedar $1000 6Ygp Gold6022310700 Fire-2 483 1549000 HP60389960 00 497 1489000 Hyper- 603398320 rhrsl 6601449000 Kyosho 6023930960 3605T449369000 Thrst- 603649930 fl3dsler 5203399000 Trbo 603609090 530-I 5991549000 Trbo 601519390 550-2 5921459000 Notes listed alphabelically l limed 333 74 308 74 71 95 343 72 98 72 96 92 93 86 2332 2320 3809 2350 2076 2049 2039 0060 0076 0359 0065 0062 0093 0300 Lets draw some conclusions informa tion First seems motors display ks fall roughly three categories conve nience Ill list 1/k categories instead thus 2300 2000 1800 rpm/volt aver age same prop battery higher 1/k higher rpmexcept influence R see below Next no matter what motor k factor clear motors tested needed average about 73 watts input power turn sample prop selected value 9000 rpm same time motors notice ably larger Rs needed input power general can expect shorter and/or slower flights R increases Within given k range motors lowest R clearly developed greatest power turned prop fastest course exactly what expected Equation 3 above ef fect x R term subtracts voltage voltage applied motor terminals ideal work-producing part motor thinks lower voltage being applied what really above data case facts dont seem add up Its case 360 ST motor nominal 1/k 2300 group does have lowest R group still performs better should comparativelyin 60-volt test point clear experimental error perhaps fact motor has fixed off-neutral brush angle explains result will dig further follow up later co lumn Besides Im getting more re quests information about brush angle Finally last piece data flew motors new Skyvolt design Guess what average worked best bench worked best air though some pretty close calls Heres closing thought view above lot information its serious Electric modelers need Nothing given tells us what power level mo tors rated Thats up manufacturer Neither does tell what maximum recom mended operating current should Thats up manufacturer Neither does tell what maximum recommended no-load voltage rpm Thats up manufacturer course modeldom should also have rely columnists information motor k R either things manu facturer should put motor nameplate DONT YOU AGREE Coming future columns meet nouncements extensive prop data can used motor info above performance information new Astro Model 112 Con stant Current Chargerand Please direct comment question SASE please author address given logo area top column Dont send things magazine editorial offices just have forward July 1989 147 BALSA HOT LINE Call 18061 7456394 lOam 6pm cancel Time FOAM CORE FLOATS PLANS AND KITS WE OFFER SELECTION OF FLOAT PLANS AND KITS FOR 4 12 POUND AIRPLANES WITH y HULL DESIGN IN USE SINCE 1972 SEND SASE FOR CATALOG SHEET KIRCHER R/C PRODUCTS [NC 9 SHEFFIELD WAY CLARK NJ 07066 VEND MOUNTS THE VIBRATION KILLER Fail Iu/ pwI tIn, ,,, iOlQtin 25 ngin, Fjl,ituaIlylIti,wIi ,nne munt Oln/cali5atinredulin t 70% M, 86% 640,,t 01 mounting pOre0~~ e~ , Send 51200 ofleok Omny Order PO kit GSA PSOSUCTS P0 BOO 35025 SARASOTA FL 34232 813 307-4250 FL reeidnt cod 72*aI, Ia INFO 8200 Oredited 11111 order 11 Blades New 40 Pack 100 Pack $485 $895 Deliveried Berkeley Trading CoCheek MO PO Box 26 Berkeley Springs WV 25411