Radio Contrbl Sport & Aerobatics Ron Van Putte WHEN last time finished airplane compared center gravity CU the pians found same place Ive building RC airplanes since i94 happened once Usually small difference once got overly enthusiastic airplane structure primer and/or paint add lot nose weight fact time Ive ended up nose-heavy airplanes built Don Lowes Phoenix series airplanes swept wing shifts wing aerodynamic center well aft allows CU fur ther back fuselage normal straight-wing airplanes have built two Phoenix 3 airplanes Phoenix 5 two Phoenix 6s Phoe nix 8 Ive used luxury having worry about having tailheavy fact add six ounces lead tail Phoenix 6 get CU far enough back very few straight-wing builders have add much weight tail air plane Well finished straight-wing airplane ago needed four ounces lead get CU spot plans airplane Im referring Elliptic doesnt have what people would call straight wing either because has essentially elliptic wing planform hence name airplane So did have add much lead tail Its basically because decided use four-cycle engine Elliptic US Eagle PO Box 1902 Ureenville TX 75401 can flown either 51 75 two-cycle engine 60 120 four-cycle engine its primarily set up 05 61 fourcycle engines both heavier bigger two-cycle engines approximately equal power risky simply bolt four-cycle engine indiscriminately potential problem drama tic CU shift Youll note wrote fourcycle engine heavier bigger two-cycle engine corresponding power Because way theyre made CU four-cycle engine lot further firewall two-cycle engines So engines weighed same airplane CU would still shift forward because engine CU further forward four-cycle engine factor compounded extra weight fourcycle engines two facts can cause unsuspecting builder big problem tries get CU airplane correct place obvious solution excessive shift airplane CU bolting four-cycle engine cut nose airplane off enough airplane balances right place Anyone has tried has discovered air plane may have almost no nose example calculated firewall should Elliptic discovered Id have firewall sitting leading edge wing way World War airplanes such short noses has way out prob lems case too tail long distance airplane CU adding modest amount weight tail has enormous effect shifting airplane CU back Most us have discovered fact dismay got too much paint airplanes tail Now can work advantage What intend to present tech nique use deciding much move firewall back versus much tail weight add installing fourcycle engine ill follow way decide much weight add airplane has wrong CU want move plans indicate First assume already know airplane CU supposed can determine weight CU typical 60 two-cycle comparable four-cycle engine installation Weighing engines shouldnt present problem baby scales available sure have correct size propeller spinner stalled engine four-cycle props much larger two-cycle cousins 48 Model Aviation FitI Center gravity CG consideratIons Ron addresses couple cases month First find out much noec p ian must shortened instaii heavier engine want keep CG same piace socond determine much baliast weight add either nose tall get piane baiance weigh Determining CG engines done finding out balance sharp edge Granted impossible actually get engine balance can move back forth observe point doesnt want tip badly either way Mark CG engine/prop spinner case engine Measure distance between airplane CG engine/prop/spinner CG engine its normal position motor mount way youre plan ning use metal motor mount also clude determining weight CG engine group Figure 1 shows respective weights CG distances two-cycle instal lation corresponding four-cycle Note Wi Dl twocycle installation W2 fourcycle distance D2 equation distance CG four-cycle engine group should front airplane CG assuming no tail weight added may need add tail weight calculation leaves airplane reasonable nose length first calculation results un reasonably short length decide what reasonable length D2 use Figure 2 determine much tail weight necessary get proper airplane CG location Youll probably want try few nose length tail weight combina tions come up neither have cut off too much nose nor add too much tail weight Now what about builder doesnt want switch engines just wants get new airplane balance should Im assuming airplane tail-heavy weight must added near nose get airplane CG right spot Figure 3 demonstrates situation case W basic weight airplane stance airplane CG must moved forward D distance place weight added W added weight Its hard see fur ther forward weight can added less has used some strange reason youve built nose-heavy airplane same equation can used determine much tail weight needed get prop er airplane CG location doubt will need unless new airplane Phoenix reminds Phoenix 3 260 think leading edge sweep wing build box fuselage back wing carry battery pack could minimize tail weight Continued page 147 Talldraggers seen 84 Nate L heres nice look Ron Chidgeys new Tar Baby Turnaround plane Enya 12 old 4stroko power R Maurice Maroney Hanford CA entered Golden AgelIke craft Sportsman Pattern c4 4Cy 4C3 S WE NEED DEALERS! KITS ATLANTA 60$22275 OMEGA 60$20588 SIGMA 1160$24550 ACRO STAR 60$16315 QUATRO 40$15061 EXCEED4O .. $15188 HARDWARE IM SERVO MOUNTS.. $164 IM CAM LOCKS $149 MKCONTROLHORNS. $ 88 DIGICON HORNS $105 DIGICON TUBES IN TUBES operation flaps 10 DIGICON HINGES 12. $161 TETTRA AIR FILTERS 7912 14mm$277 ISHIPLA FUEL FILTERS. $200 ISHIPLA PUSH RODS. $130 PULL-PULL HARDWARE $346 PULL-PULL HORN$ 74 WHEELS prices wheell TETTRA WHEELS.. $513 5055 60mm type R V U MK ALUMINUM WHEELS. $841 152 56 60mm Radial MK PLASTIC WHEELS 31 4550 55 60mm Radial IM PLASTIC WHEELS 3035mm $1 97 40 45mm $223 50mm $24855mm $272 60mm $29765mm $322 TETTRA SPARE TIRES$221 Ispecify size 8 type MKFUELTANKS 4SOccllSozISLIM 196 400cc1133ozISLIM . $169 360cc 112 oz ROUND. $138 300cclOozIROUND. $138 360cc 112 ozl OVAL$138 320cc 11 07 ozIOVAL.. $138 IMlOOOcc $392 TOOLS & ACCESS. TETTRA TUBING BENDER $476 NIWA TOOL KIT $895 TETTRA GLOW PLUG WRENCH$430 IM ENGINE TEST BENCH $428 IM STAND FOR BENCH $2673 MK WIRE BENDER$775 MSK TRANSMITTER CASE $2800 HATORI HEADERS AND PIPES #601 10cc PIPE$ 3423 #401 75cc PIPE$ 2995 Headers fit YS OS Enya Webbra OPS & Ross RETRACTS e parts availabiel MK S60 S40 NOSE$ 1733 MAINS$ 2450 Shipping handling ordars up $2000 add $195 $2001 $5000 add $350 over $5000 add $500 Except Kits oversizedi add $700 angina orders add $300 California residents must add 6A% sales tax VISA MasterCard ac cepted Add $190 COD International orders welcome additional shipping charges will applied Send $100 Catalog Information San Francisco see products San Antonio Hobby Shop 415 941-1278 Alameda Hobbycraft 523-3980 10 am l PSY 415467-3170 May1985 49 RIC GOLDEN GATE HOBBIES PO Box 4412 Burlingame CA 94010 Monday hru Friday Up til now needed thick CA make whatever could get Because extra-thick cyanoacrylate youve asking finally CG Slow Jet made professional standards formulation quality control right USA made sure just way wanted before sold drop Give Slow Jet try think youll agree extra care weve given reallyCARL GOLDBERG does makeabigMODELS INC difference about dozen models manufactured Andreas necessarily cheap again arent kits market fiberglass finish best tradition type construction As stated previously latest radio equipment presented Paul Hoisten Bob Renaud Pete Waters Mark Stidham interesting presentation safety aspects cross-country fly ing stressing safety chase vehi cle its occupants An F3B question answer session covered just about aspect topic lighter side Dave Batey Milwaukee Thermal Soar ers showed above-average film ther mal soaring filmed Super-8 camera mounted atop Sailplane rounded out two-day session show-and-tell MARCS style weekend well spent So club looking different kind club project look what MARCS did After last time 80 modelers got together two daysand went home still talking another Good lift Dan Pruss 131 F Pennington Ln Plainfield IL 60544 RC Aerobatics/Van Putte Continued page 49 add thats another story recently came across bottle Wilhold glue misplaced back cupboard left several years separated top part darkcolored very thin consistency bottom layer appeared about right color thick could barely get piece A2 music wire through tried stir through top remembered heat makes glues watery put bot tle top microwave oven ran 30 seconds stirred did same routine several times until glue quite warmand thoroughly mixed procedure doesnt seem have affected its gluing ability Id interested hearing anyone about reasons what did polymer chemist perhaps Meanwhile plan see what happens leaving can see making trial glue joints periodically enjoyment RC augmented regu larly large envelope stuffed RC-oriented club newsletters arrives AMA HQ last batch came across two items general interest first May1985 147 V I j 1 Use CG X-Cel for-S controlled accel eration Slow Jet Youll get rockhard crystal-clear applications Slow Jet available squeezable clogresistant half-ounce one-ounce twoounce boffles MADE RU SA C 1985 CARL GOLDBERG MOUINC Introducing Slow Jet extra-thick CA glue Carl Goldberg 4735 WEST CHICAGO AVE CHICAGO IL 60651 Want REP-UP Pieps Average luveutory 4900 Prep! Over SD Sizes A/I Eveuts New Aheut Custen Tuned Engines P Coabat Raciag Free Flight 6 Sport Ceaupetitien Accessories 6 Parts Pp/eu Raciug Pattera 6 Sport FA 6 U/C Nag laveutery! Specialists Custom Ce ZD 6 Reed Eugiaes Std 6 R/C Custom Parts Ce Engines Complete lnveutorp 0 ludividual Stock Parts Curreat ZD 6 Medal/iou Eugines Maup New Parts Discontirnied ox Engines Rep/ku Owick 23 29 64 Engines /gnitioa Engiuc Accessories Visa 6 MasterCard Welcome Detailed Drochure Scud 751 Kustom Kratsmauship RD lox 29D Laguna Ni/Is CA 325 Ph 7141395162 discussed quite few club newsletters subject noise mufflers Most about necessity improve noise situation using better mufflers Almost club Ive involved last 15 years least formal muffler rule Some quite specific Nowadays almost everyone uses mufflers engines However middle Sixties almost nobody used Engines loud muffler propo nents claimed use mufflers would guarantee against loss fly ing field due noise problems early mufflers did lot quiet engines expense losing lot power Modern mufflers good job reduc ing noise sacrificing power remember thinking time club Western Ohio Radio Kontrol Socie ty required use mufflers about 1967 question time before everyone would forget what like before started using mufflers noise complaints would start again As know situation upon us As much hate think unless dra matic new improvements made mufflers two-cycle engines lot flying fields will lost other alternative can see clubs noise problems ban two-cycle engines favor four-cycle engines thats done wonder long will take flying field neighbors forget before four-cycle engines required start complaining again second item Id like share club newsletters pub lished Mount Rainier Radio Con trol Society Newsletter Tacoma WA Its semi-anonymous author Bill D wrote Old Threat Finally Identified Field Psychologist Glitchus Crashemup commonly known glitch has finally identified after years research dread malady preys upon certain segment species Homo Sapiens known RC Pilots normally lurking open fields grown men play model air craft glitch very dangerous full plumage adult male should approached experienced glitch hunters wielding loaded field strength meters has bite produces im mediate reactions beginning ner vous shaking twitching thumbs sequence symptoms often followed cries dont have Splintering thudding noises occur almost immediately point vic tim usually lapses depression may become militant approached next few minutes glitch invisible real imagined experience enemy should reported immediate ly field psychologist Ron Van Putte 111 Sleepy Oaks Rd Ft Walton Beach FL 32548 RC Electrics/Kopski Continued page 51 Cd will under charge eventually reach voltage its terminals equal about 15 x 6 about nine volts since Ni-Cds float up 15 volts per cell under charge take source volt age auto battery 12 volts avail able circuit voltage simply three volts difference 12 nine volts voltage appears across charging circuit resistance ear lier lessons circuit current charg ing current established choosing suitable resistor charge system design has plenty resistors choose Lets figure out make choice Last month saw several ways write Ohms Law Youll remember law relates three common elec trical terms voltage V current resistance R particular saw resistance can found dividing available circuit voltage ACV cir cuit current like R As example lets say six-cell pack made up 800 MAh cells Three amps very good charge current use 148 Model Aviation -I A monthly publication covering International RC Soaring Scene $1 6/yr US Canada & Mexico $24/yr elsewhere via airmail Post Office Box 269 Peterborough NH 03458
Edition: Model Aviation - 1985/05
Page Numbers: 48, 49, 147, 148
Radio Contrbl Sport & Aerobatics Ron Van Putte WHEN last time finished airplane compared center gravity CU the pians found same place Ive building RC airplanes since i94 happened once Usually small difference once got overly enthusiastic airplane structure primer and/or paint add lot nose weight fact time Ive ended up nose-heavy airplanes built Don Lowes Phoenix series airplanes swept wing shifts wing aerodynamic center well aft allows CU fur ther back fuselage normal straight-wing airplanes have built two Phoenix 3 airplanes Phoenix 5 two Phoenix 6s Phoe nix 8 Ive used luxury having worry about having tailheavy fact add six ounces lead tail Phoenix 6 get CU far enough back very few straight-wing builders have add much weight tail air plane Well finished straight-wing airplane ago needed four ounces lead get CU spot plans airplane Im referring Elliptic doesnt have what people would call straight wing either because has essentially elliptic wing planform hence name airplane So did have add much lead tail Its basically because decided use four-cycle engine Elliptic US Eagle PO Box 1902 Ureenville TX 75401 can flown either 51 75 two-cycle engine 60 120 four-cycle engine its primarily set up 05 61 fourcycle engines both heavier bigger two-cycle engines approximately equal power risky simply bolt four-cycle engine indiscriminately potential problem drama tic CU shift Youll note wrote fourcycle engine heavier bigger two-cycle engine corresponding power Because way theyre made CU four-cycle engine lot further firewall two-cycle engines So engines weighed same airplane CU would still shift forward because engine CU further forward four-cycle engine factor compounded extra weight fourcycle engines two facts can cause unsuspecting builder big problem tries get CU airplane correct place obvious solution excessive shift airplane CU bolting four-cycle engine cut nose airplane off enough airplane balances right place Anyone has tried has discovered air plane may have almost no nose example calculated firewall should Elliptic discovered Id have firewall sitting leading edge wing way World War airplanes such short noses has way out prob lems case too tail long distance airplane CU adding modest amount weight tail has enormous effect shifting airplane CU back Most us have discovered fact dismay got too much paint airplanes tail Now can work advantage What intend to present tech nique use deciding much move firewall back versus much tail weight add installing fourcycle engine ill follow way decide much weight add airplane has wrong CU want move plans indicate First assume already know airplane CU supposed can determine weight CU typical 60 two-cycle comparable four-cycle engine installation Weighing engines shouldnt present problem baby scales available sure have correct size propeller spinner stalled engine four-cycle props much larger two-cycle cousins 48 Model Aviation FitI Center gravity CG consideratIons Ron addresses couple cases month First find out much noec p ian must shortened instaii heavier engine want keep CG same piace socond determine much baliast weight add either nose tall get piane baiance weigh Determining CG engines done finding out balance sharp edge Granted impossible actually get engine balance can move back forth observe point doesnt want tip badly either way Mark CG engine/prop spinner case engine Measure distance between airplane CG engine/prop/spinner CG engine its normal position motor mount way youre plan ning use metal motor mount also clude determining weight CG engine group Figure 1 shows respective weights CG distances two-cycle instal lation corresponding four-cycle Note Wi Dl twocycle installation W2 fourcycle distance D2 equation distance CG four-cycle engine group should front airplane CG assuming no tail weight added may need add tail weight calculation leaves airplane reasonable nose length first calculation results un reasonably short length decide what reasonable length D2 use Figure 2 determine much tail weight necessary get proper airplane CG location Youll probably want try few nose length tail weight combina tions come up neither have cut off too much nose nor add too much tail weight Now what about builder doesnt want switch engines just wants get new airplane balance should Im assuming airplane tail-heavy weight must added near nose get airplane CG right spot Figure 3 demonstrates situation case W basic weight airplane stance airplane CG must moved forward D distance place weight added W added weight Its hard see fur ther forward weight can added less has used some strange reason youve built nose-heavy airplane same equation can used determine much tail weight needed get prop er airplane CG location doubt will need unless new airplane Phoenix reminds Phoenix 3 260 think leading edge sweep wing build box fuselage back wing carry battery pack could minimize tail weight Continued page 147 Talldraggers seen 84 Nate L heres nice look Ron Chidgeys new Tar Baby Turnaround plane Enya 12 old 4stroko power R Maurice Maroney Hanford CA entered Golden AgelIke craft Sportsman Pattern c4 4Cy 4C3 S WE NEED DEALERS! KITS ATLANTA 60$22275 OMEGA 60$20588 SIGMA 1160$24550 ACRO STAR 60$16315 QUATRO 40$15061 EXCEED4O .. $15188 HARDWARE IM SERVO MOUNTS.. $164 IM CAM LOCKS $149 MKCONTROLHORNS. $ 88 DIGICON HORNS $105 DIGICON TUBES IN TUBES operation flaps 10 DIGICON HINGES 12. $161 TETTRA AIR FILTERS 7912 14mm$277 ISHIPLA FUEL FILTERS. $200 ISHIPLA PUSH RODS. $130 PULL-PULL HARDWARE $346 PULL-PULL HORN$ 74 WHEELS prices wheell TETTRA WHEELS.. $513 5055 60mm type R V U MK ALUMINUM WHEELS. $841 152 56 60mm Radial MK PLASTIC WHEELS 31 4550 55 60mm Radial IM PLASTIC WHEELS 3035mm $1 97 40 45mm $223 50mm $24855mm $272 60mm $29765mm $322 TETTRA SPARE TIRES$221 Ispecify size 8 type MKFUELTANKS 4SOccllSozISLIM 196 400cc1133ozISLIM . $169 360cc 112 oz ROUND. $138 300cclOozIROUND. $138 360cc 112 ozl OVAL$138 320cc 11 07 ozIOVAL.. $138 IMlOOOcc $392 TOOLS & ACCESS. TETTRA TUBING BENDER $476 NIWA TOOL KIT $895 TETTRA GLOW PLUG WRENCH$430 IM ENGINE TEST BENCH $428 IM STAND FOR BENCH $2673 MK WIRE BENDER$775 MSK TRANSMITTER CASE $2800 HATORI HEADERS AND PIPES #601 10cc PIPE$ 3423 #401 75cc PIPE$ 2995 Headers fit YS OS Enya Webbra OPS & Ross RETRACTS e parts availabiel MK S60 S40 NOSE$ 1733 MAINS$ 2450 Shipping handling ordars up $2000 add $195 $2001 $5000 add $350 over $5000 add $500 Except Kits oversizedi add $700 angina orders add $300 California residents must add 6A% sales tax VISA MasterCard ac cepted Add $190 COD International orders welcome additional shipping charges will applied Send $100 Catalog Information San Francisco see products San Antonio Hobby Shop 415 941-1278 Alameda Hobbycraft 523-3980 10 am l PSY 415467-3170 May1985 49 RIC GOLDEN GATE HOBBIES PO Box 4412 Burlingame CA 94010 Monday hru Friday Up til now needed thick CA make whatever could get Because extra-thick cyanoacrylate youve asking finally CG Slow Jet made professional standards formulation quality control right USA made sure just way wanted before sold drop Give Slow Jet try think youll agree extra care weve given reallyCARL GOLDBERG does makeabigMODELS INC difference about dozen models manufactured Andreas necessarily cheap again arent kits market fiberglass finish best tradition type construction As stated previously latest radio equipment presented Paul Hoisten Bob Renaud Pete Waters Mark Stidham interesting presentation safety aspects cross-country fly ing stressing safety chase vehi cle its occupants An F3B question answer session covered just about aspect topic lighter side Dave Batey Milwaukee Thermal Soar ers showed above-average film ther mal soaring filmed Super-8 camera mounted atop Sailplane rounded out two-day session show-and-tell MARCS style weekend well spent So club looking different kind club project look what MARCS did After last time 80 modelers got together two daysand went home still talking another Good lift Dan Pruss 131 F Pennington Ln Plainfield IL 60544 RC Aerobatics/Van Putte Continued page 49 add thats another story recently came across bottle Wilhold glue misplaced back cupboard left several years separated top part darkcolored very thin consistency bottom layer appeared about right color thick could barely get piece A2 music wire through tried stir through top remembered heat makes glues watery put bot tle top microwave oven ran 30 seconds stirred did same routine several times until glue quite warmand thoroughly mixed procedure doesnt seem have affected its gluing ability Id interested hearing anyone about reasons what did polymer chemist perhaps Meanwhile plan see what happens leaving can see making trial glue joints periodically enjoyment RC augmented regu larly large envelope stuffed RC-oriented club newsletters arrives AMA HQ last batch came across two items general interest first May1985 147 V I j 1 Use CG X-Cel for-S controlled accel eration Slow Jet Youll get rockhard crystal-clear applications Slow Jet available squeezable clogresistant half-ounce one-ounce twoounce boffles MADE RU SA C 1985 CARL GOLDBERG MOUINC Introducing Slow Jet extra-thick CA glue Carl Goldberg 4735 WEST CHICAGO AVE CHICAGO IL 60651 Want REP-UP Pieps Average luveutory 4900 Prep! Over SD Sizes A/I Eveuts New Aheut Custen Tuned Engines P Coabat Raciag Free Flight 6 Sport Ceaupetitien Accessories 6 Parts Pp/eu Raciug Pattera 6 Sport FA 6 U/C Nag laveutery! Specialists Custom Ce ZD 6 Reed Eugiaes Std 6 R/C Custom Parts Ce Engines Complete lnveutorp 0 ludividual Stock Parts Curreat ZD 6 Medal/iou Eugines Maup New Parts Discontirnied ox Engines Rep/ku Owick 23 29 64 Engines /gnitioa Engiuc Accessories Visa 6 MasterCard Welcome Detailed Drochure Scud 751 Kustom Kratsmauship RD lox 29D Laguna Ni/Is CA 325 Ph 7141395162 discussed quite few club newsletters subject noise mufflers Most about necessity improve noise situation using better mufflers Almost club Ive involved last 15 years least formal muffler rule Some quite specific Nowadays almost everyone uses mufflers engines However middle Sixties almost nobody used Engines loud muffler propo nents claimed use mufflers would guarantee against loss fly ing field due noise problems early mufflers did lot quiet engines expense losing lot power Modern mufflers good job reduc ing noise sacrificing power remember thinking time club Western Ohio Radio Kontrol Socie ty required use mufflers about 1967 question time before everyone would forget what like before started using mufflers noise complaints would start again As know situation upon us As much hate think unless dra matic new improvements made mufflers two-cycle engines lot flying fields will lost other alternative can see clubs noise problems ban two-cycle engines favor four-cycle engines thats done wonder long will take flying field neighbors forget before four-cycle engines required start complaining again second item Id like share club newsletters pub lished Mount Rainier Radio Con trol Society Newsletter Tacoma WA Its semi-anonymous author Bill D wrote Old Threat Finally Identified Field Psychologist Glitchus Crashemup commonly known glitch has finally identified after years research dread malady preys upon certain segment species Homo Sapiens known RC Pilots normally lurking open fields grown men play model air craft glitch very dangerous full plumage adult male should approached experienced glitch hunters wielding loaded field strength meters has bite produces im mediate reactions beginning ner vous shaking twitching thumbs sequence symptoms often followed cries dont have Splintering thudding noises occur almost immediately point vic tim usually lapses depression may become militant approached next few minutes glitch invisible real imagined experience enemy should reported immediate ly field psychologist Ron Van Putte 111 Sleepy Oaks Rd Ft Walton Beach FL 32548 RC Electrics/Kopski Continued page 51 Cd will under charge eventually reach voltage its terminals equal about 15 x 6 about nine volts since Ni-Cds float up 15 volts per cell under charge take source volt age auto battery 12 volts avail able circuit voltage simply three volts difference 12 nine volts voltage appears across charging circuit resistance ear lier lessons circuit current charg ing current established choosing suitable resistor charge system design has plenty resistors choose Lets figure out make choice Last month saw several ways write Ohms Law Youll remember law relates three common elec trical terms voltage V current resistance R particular saw resistance can found dividing available circuit voltage ACV cir cuit current like R As example lets say six-cell pack made up 800 MAh cells Three amps very good charge current use 148 Model Aviation -I A monthly publication covering International RC Soaring Scene $1 6/yr US Canada & Mexico $24/yr elsewhere via airmail Post Office Box 269 Peterborough NH 03458
Edition: Model Aviation - 1985/05
Page Numbers: 48, 49, 147, 148
Radio Contrbl Sport & Aerobatics Ron Van Putte WHEN last time finished airplane compared center gravity CU the pians found same place Ive building RC airplanes since i94 happened once Usually small difference once got overly enthusiastic airplane structure primer and/or paint add lot nose weight fact time Ive ended up nose-heavy airplanes built Don Lowes Phoenix series airplanes swept wing shifts wing aerodynamic center well aft allows CU fur ther back fuselage normal straight-wing airplanes have built two Phoenix 3 airplanes Phoenix 5 two Phoenix 6s Phoe nix 8 Ive used luxury having worry about having tailheavy fact add six ounces lead tail Phoenix 6 get CU far enough back very few straight-wing builders have add much weight tail air plane Well finished straight-wing airplane ago needed four ounces lead get CU spot plans airplane Im referring Elliptic doesnt have what people would call straight wing either because has essentially elliptic wing planform hence name airplane So did have add much lead tail Its basically because decided use four-cycle engine Elliptic US Eagle PO Box 1902 Ureenville TX 75401 can flown either 51 75 two-cycle engine 60 120 four-cycle engine its primarily set up 05 61 fourcycle engines both heavier bigger two-cycle engines approximately equal power risky simply bolt four-cycle engine indiscriminately potential problem drama tic CU shift Youll note wrote fourcycle engine heavier bigger two-cycle engine corresponding power Because way theyre made CU four-cycle engine lot further firewall two-cycle engines So engines weighed same airplane CU would still shift forward because engine CU further forward four-cycle engine factor compounded extra weight fourcycle engines two facts can cause unsuspecting builder big problem tries get CU airplane correct place obvious solution excessive shift airplane CU bolting four-cycle engine cut nose airplane off enough airplane balances right place Anyone has tried has discovered air plane may have almost no nose example calculated firewall should Elliptic discovered Id have firewall sitting leading edge wing way World War airplanes such short noses has way out prob lems case too tail long distance airplane CU adding modest amount weight tail has enormous effect shifting airplane CU back Most us have discovered fact dismay got too much paint airplanes tail Now can work advantage What intend to present tech nique use deciding much move firewall back versus much tail weight add installing fourcycle engine ill follow way decide much weight add airplane has wrong CU want move plans indicate First assume already know airplane CU supposed can determine weight CU typical 60 two-cycle comparable four-cycle engine installation Weighing engines shouldnt present problem baby scales available sure have correct size propeller spinner stalled engine four-cycle props much larger two-cycle cousins 48 Model Aviation FitI Center gravity CG consideratIons Ron addresses couple cases month First find out much noec p ian must shortened instaii heavier engine want keep CG same piace socond determine much baliast weight add either nose tall get piane baiance weigh Determining CG engines done finding out balance sharp edge Granted impossible actually get engine balance can move back forth observe point doesnt want tip badly either way Mark CG engine/prop spinner case engine Measure distance between airplane CG engine/prop/spinner CG engine its normal position motor mount way youre plan ning use metal motor mount also clude determining weight CG engine group Figure 1 shows respective weights CG distances two-cycle instal lation corresponding four-cycle Note Wi Dl twocycle installation W2 fourcycle distance D2 equation distance CG four-cycle engine group should front airplane CG assuming no tail weight added may need add tail weight calculation leaves airplane reasonable nose length first calculation results un reasonably short length decide what reasonable length D2 use Figure 2 determine much tail weight necessary get proper airplane CG location Youll probably want try few nose length tail weight combina tions come up neither have cut off too much nose nor add too much tail weight Now what about builder doesnt want switch engines just wants get new airplane balance should Im assuming airplane tail-heavy weight must added near nose get airplane CG right spot Figure 3 demonstrates situation case W basic weight airplane stance airplane CG must moved forward D distance place weight added W added weight Its hard see fur ther forward weight can added less has used some strange reason youve built nose-heavy airplane same equation can used determine much tail weight needed get prop er airplane CG location doubt will need unless new airplane Phoenix reminds Phoenix 3 260 think leading edge sweep wing build box fuselage back wing carry battery pack could minimize tail weight Continued page 147 Talldraggers seen 84 Nate L heres nice look Ron Chidgeys new Tar Baby Turnaround plane Enya 12 old 4stroko power R Maurice Maroney Hanford CA entered Golden AgelIke craft Sportsman Pattern c4 4Cy 4C3 S WE NEED DEALERS! KITS ATLANTA 60$22275 OMEGA 60$20588 SIGMA 1160$24550 ACRO STAR 60$16315 QUATRO 40$15061 EXCEED4O .. $15188 HARDWARE IM SERVO MOUNTS.. $164 IM CAM LOCKS $149 MKCONTROLHORNS. $ 88 DIGICON HORNS $105 DIGICON TUBES IN TUBES operation flaps 10 DIGICON HINGES 12. $161 TETTRA AIR FILTERS 7912 14mm$277 ISHIPLA FUEL FILTERS. $200 ISHIPLA PUSH RODS. $130 PULL-PULL HARDWARE $346 PULL-PULL HORN$ 74 WHEELS prices wheell TETTRA WHEELS.. $513 5055 60mm type R V U MK ALUMINUM WHEELS. $841 152 56 60mm Radial MK PLASTIC WHEELS 31 4550 55 60mm Radial IM PLASTIC WHEELS 3035mm $1 97 40 45mm $223 50mm $24855mm $272 60mm $29765mm $322 TETTRA SPARE TIRES$221 Ispecify size 8 type MKFUELTANKS 4SOccllSozISLIM 196 400cc1133ozISLIM . $169 360cc 112 oz ROUND. $138 300cclOozIROUND. $138 360cc 112 ozl OVAL$138 320cc 11 07 ozIOVAL.. $138 IMlOOOcc $392 TOOLS & ACCESS. TETTRA TUBING BENDER $476 NIWA TOOL KIT $895 TETTRA GLOW PLUG WRENCH$430 IM ENGINE TEST BENCH $428 IM STAND FOR BENCH $2673 MK WIRE BENDER$775 MSK TRANSMITTER CASE $2800 HATORI HEADERS AND PIPES #601 10cc PIPE$ 3423 #401 75cc PIPE$ 2995 Headers fit YS OS Enya Webbra OPS & Ross RETRACTS e parts availabiel MK S60 S40 NOSE$ 1733 MAINS$ 2450 Shipping handling ordars up $2000 add $195 $2001 $5000 add $350 over $5000 add $500 Except Kits oversizedi add $700 angina orders add $300 California residents must add 6A% sales tax VISA MasterCard ac cepted Add $190 COD International orders welcome additional shipping charges will applied Send $100 Catalog Information San Francisco see products San Antonio Hobby Shop 415 941-1278 Alameda Hobbycraft 523-3980 10 am l PSY 415467-3170 May1985 49 RIC GOLDEN GATE HOBBIES PO Box 4412 Burlingame CA 94010 Monday hru Friday Up til now needed thick CA make whatever could get Because extra-thick cyanoacrylate youve asking finally CG Slow Jet made professional standards formulation quality control right USA made sure just way wanted before sold drop Give Slow Jet try think youll agree extra care weve given reallyCARL GOLDBERG does makeabigMODELS INC difference about dozen models manufactured Andreas necessarily cheap again arent kits market fiberglass finish best tradition type construction As stated previously latest radio equipment presented Paul Hoisten Bob Renaud Pete Waters Mark Stidham interesting presentation safety aspects cross-country fly ing stressing safety chase vehi cle its occupants An F3B question answer session covered just about aspect topic lighter side Dave Batey Milwaukee Thermal Soar ers showed above-average film ther mal soaring filmed Super-8 camera mounted atop Sailplane rounded out two-day session show-and-tell MARCS style weekend well spent So club looking different kind club project look what MARCS did After last time 80 modelers got together two daysand went home still talking another Good lift Dan Pruss 131 F Pennington Ln Plainfield IL 60544 RC Aerobatics/Van Putte Continued page 49 add thats another story recently came across bottle Wilhold glue misplaced back cupboard left several years separated top part darkcolored very thin consistency bottom layer appeared about right color thick could barely get piece A2 music wire through tried stir through top remembered heat makes glues watery put bot tle top microwave oven ran 30 seconds stirred did same routine several times until glue quite warmand thoroughly mixed procedure doesnt seem have affected its gluing ability Id interested hearing anyone about reasons what did polymer chemist perhaps Meanwhile plan see what happens leaving can see making trial glue joints periodically enjoyment RC augmented regu larly large envelope stuffed RC-oriented club newsletters arrives AMA HQ last batch came across two items general interest first May1985 147 V I j 1 Use CG X-Cel for-S controlled accel eration Slow Jet Youll get rockhard crystal-clear applications Slow Jet available squeezable clogresistant half-ounce one-ounce twoounce boffles MADE RU SA C 1985 CARL GOLDBERG MOUINC Introducing Slow Jet extra-thick CA glue Carl Goldberg 4735 WEST CHICAGO AVE CHICAGO IL 60651 Want REP-UP Pieps Average luveutory 4900 Prep! Over SD Sizes A/I Eveuts New Aheut Custen Tuned Engines P Coabat Raciag Free Flight 6 Sport Ceaupetitien Accessories 6 Parts Pp/eu Raciug Pattera 6 Sport FA 6 U/C Nag laveutery! Specialists Custom Ce ZD 6 Reed Eugiaes Std 6 R/C Custom Parts Ce Engines Complete lnveutorp 0 ludividual Stock Parts Curreat ZD 6 Medal/iou Eugines Maup New Parts Discontirnied ox Engines Rep/ku Owick 23 29 64 Engines /gnitioa Engiuc Accessories Visa 6 MasterCard Welcome Detailed Drochure Scud 751 Kustom Kratsmauship RD lox 29D Laguna Ni/Is CA 325 Ph 7141395162 discussed quite few club newsletters subject noise mufflers Most about necessity improve noise situation using better mufflers Almost club Ive involved last 15 years least formal muffler rule Some quite specific Nowadays almost everyone uses mufflers engines However middle Sixties almost nobody used Engines loud muffler propo nents claimed use mufflers would guarantee against loss fly ing field due noise problems early mufflers did lot quiet engines expense losing lot power Modern mufflers good job reduc ing noise sacrificing power remember thinking time club Western Ohio Radio Kontrol Socie ty required use mufflers about 1967 question time before everyone would forget what like before started using mufflers noise complaints would start again As know situation upon us As much hate think unless dra matic new improvements made mufflers two-cycle engines lot flying fields will lost other alternative can see clubs noise problems ban two-cycle engines favor four-cycle engines thats done wonder long will take flying field neighbors forget before four-cycle engines required start complaining again second item Id like share club newsletters pub lished Mount Rainier Radio Con trol Society Newsletter Tacoma WA Its semi-anonymous author Bill D wrote Old Threat Finally Identified Field Psychologist Glitchus Crashemup commonly known glitch has finally identified after years research dread malady preys upon certain segment species Homo Sapiens known RC Pilots normally lurking open fields grown men play model air craft glitch very dangerous full plumage adult male should approached experienced glitch hunters wielding loaded field strength meters has bite produces im mediate reactions beginning ner vous shaking twitching thumbs sequence symptoms often followed cries dont have Splintering thudding noises occur almost immediately point vic tim usually lapses depression may become militant approached next few minutes glitch invisible real imagined experience enemy should reported immediate ly field psychologist Ron Van Putte 111 Sleepy Oaks Rd Ft Walton Beach FL 32548 RC Electrics/Kopski Continued page 51 Cd will under charge eventually reach voltage its terminals equal about 15 x 6 about nine volts since Ni-Cds float up 15 volts per cell under charge take source volt age auto battery 12 volts avail able circuit voltage simply three volts difference 12 nine volts voltage appears across charging circuit resistance ear lier lessons circuit current charg ing current established choosing suitable resistor charge system design has plenty resistors choose Lets figure out make choice Last month saw several ways write Ohms Law Youll remember law relates three common elec trical terms voltage V current resistance R particular saw resistance can found dividing available circuit voltage ACV cir cuit current like R As example lets say six-cell pack made up 800 MAh cells Three amps very good charge current use 148 Model Aviation -I A monthly publication covering International RC Soaring Scene $1 6/yr US Canada & Mexico $24/yr elsewhere via airmail Post Office Box 269 Peterborough NH 03458
Edition: Model Aviation - 1985/05
Page Numbers: 48, 49, 147, 148
Radio Contrbl Sport & Aerobatics Ron Van Putte WHEN last time finished airplane compared center gravity CU the pians found same place Ive building RC airplanes since i94 happened once Usually small difference once got overly enthusiastic airplane structure primer and/or paint add lot nose weight fact time Ive ended up nose-heavy airplanes built Don Lowes Phoenix series airplanes swept wing shifts wing aerodynamic center well aft allows CU fur ther back fuselage normal straight-wing airplanes have built two Phoenix 3 airplanes Phoenix 5 two Phoenix 6s Phoe nix 8 Ive used luxury having worry about having tailheavy fact add six ounces lead tail Phoenix 6 get CU far enough back very few straight-wing builders have add much weight tail air plane Well finished straight-wing airplane ago needed four ounces lead get CU spot plans airplane Im referring Elliptic doesnt have what people would call straight wing either because has essentially elliptic wing planform hence name airplane So did have add much lead tail Its basically because decided use four-cycle engine Elliptic US Eagle PO Box 1902 Ureenville TX 75401 can flown either 51 75 two-cycle engine 60 120 four-cycle engine its primarily set up 05 61 fourcycle engines both heavier bigger two-cycle engines approximately equal power risky simply bolt four-cycle engine indiscriminately potential problem drama tic CU shift Youll note wrote fourcycle engine heavier bigger two-cycle engine corresponding power Because way theyre made CU four-cycle engine lot further firewall two-cycle engines So engines weighed same airplane CU would still shift forward because engine CU further forward four-cycle engine factor compounded extra weight fourcycle engines two facts can cause unsuspecting builder big problem tries get CU airplane correct place obvious solution excessive shift airplane CU bolting four-cycle engine cut nose airplane off enough airplane balances right place Anyone has tried has discovered air plane may have almost no nose example calculated firewall should Elliptic discovered Id have firewall sitting leading edge wing way World War airplanes such short noses has way out prob lems case too tail long distance airplane CU adding modest amount weight tail has enormous effect shifting airplane CU back Most us have discovered fact dismay got too much paint airplanes tail Now can work advantage What intend to present tech nique use deciding much move firewall back versus much tail weight add installing fourcycle engine ill follow way decide much weight add airplane has wrong CU want move plans indicate First assume already know airplane CU supposed can determine weight CU typical 60 two-cycle comparable four-cycle engine installation Weighing engines shouldnt present problem baby scales available sure have correct size propeller spinner stalled engine four-cycle props much larger two-cycle cousins 48 Model Aviation FitI Center gravity CG consideratIons Ron addresses couple cases month First find out much noec p ian must shortened instaii heavier engine want keep CG same piace socond determine much baliast weight add either nose tall get piane baiance weigh Determining CG engines done finding out balance sharp edge Granted impossible actually get engine balance can move back forth observe point doesnt want tip badly either way Mark CG engine/prop spinner case engine Measure distance between airplane CG engine/prop/spinner CG engine its normal position motor mount way youre plan ning use metal motor mount also clude determining weight CG engine group Figure 1 shows respective weights CG distances two-cycle instal lation corresponding four-cycle Note Wi Dl twocycle installation W2 fourcycle distance D2 equation distance CG four-cycle engine group should front airplane CG assuming no tail weight added may need add tail weight calculation leaves airplane reasonable nose length first calculation results un reasonably short length decide what reasonable length D2 use Figure 2 determine much tail weight necessary get proper airplane CG location Youll probably want try few nose length tail weight combina tions come up neither have cut off too much nose nor add too much tail weight Now what about builder doesnt want switch engines just wants get new airplane balance should Im assuming airplane tail-heavy weight must added near nose get airplane CG right spot Figure 3 demonstrates situation case W basic weight airplane stance airplane CG must moved forward D distance place weight added W added weight Its hard see fur ther forward weight can added less has used some strange reason youve built nose-heavy airplane same equation can used determine much tail weight needed get prop er airplane CG location doubt will need unless new airplane Phoenix reminds Phoenix 3 260 think leading edge sweep wing build box fuselage back wing carry battery pack could minimize tail weight Continued page 147 Talldraggers seen 84 Nate L heres nice look Ron Chidgeys new Tar Baby Turnaround plane Enya 12 old 4stroko power R Maurice Maroney Hanford CA entered Golden AgelIke craft Sportsman Pattern c4 4Cy 4C3 S WE NEED DEALERS! KITS ATLANTA 60$22275 OMEGA 60$20588 SIGMA 1160$24550 ACRO STAR 60$16315 QUATRO 40$15061 EXCEED4O .. $15188 HARDWARE IM SERVO MOUNTS.. $164 IM CAM LOCKS $149 MKCONTROLHORNS. $ 88 DIGICON HORNS $105 DIGICON TUBES IN TUBES operation flaps 10 DIGICON HINGES 12. $161 TETTRA AIR FILTERS 7912 14mm$277 ISHIPLA FUEL FILTERS. $200 ISHIPLA PUSH RODS. $130 PULL-PULL HARDWARE $346 PULL-PULL HORN$ 74 WHEELS prices wheell TETTRA WHEELS.. $513 5055 60mm type R V U MK ALUMINUM WHEELS. $841 152 56 60mm Radial MK PLASTIC WHEELS 31 4550 55 60mm Radial IM PLASTIC WHEELS 3035mm $1 97 40 45mm $223 50mm $24855mm $272 60mm $29765mm $322 TETTRA SPARE TIRES$221 Ispecify size 8 type MKFUELTANKS 4SOccllSozISLIM 196 400cc1133ozISLIM . $169 360cc 112 oz ROUND. $138 300cclOozIROUND. $138 360cc 112 ozl OVAL$138 320cc 11 07 ozIOVAL.. $138 IMlOOOcc $392 TOOLS & ACCESS. TETTRA TUBING BENDER $476 NIWA TOOL KIT $895 TETTRA GLOW PLUG WRENCH$430 IM ENGINE TEST BENCH $428 IM STAND FOR BENCH $2673 MK WIRE BENDER$775 MSK TRANSMITTER CASE $2800 HATORI HEADERS AND PIPES #601 10cc PIPE$ 3423 #401 75cc PIPE$ 2995 Headers fit YS OS Enya Webbra OPS & Ross RETRACTS e parts availabiel MK S60 S40 NOSE$ 1733 MAINS$ 2450 Shipping handling ordars up $2000 add $195 $2001 $5000 add $350 over $5000 add $500 Except Kits oversizedi add $700 angina orders add $300 California residents must add 6A% sales tax VISA MasterCard ac cepted Add $190 COD International orders welcome additional shipping charges will applied Send $100 Catalog Information San Francisco see products San Antonio Hobby Shop 415 941-1278 Alameda Hobbycraft 523-3980 10 am l PSY 415467-3170 May1985 49 RIC GOLDEN GATE HOBBIES PO Box 4412 Burlingame CA 94010 Monday hru Friday Up til now needed thick CA make whatever could get Because extra-thick cyanoacrylate youve asking finally CG Slow Jet made professional standards formulation quality control right USA made sure just way wanted before sold drop Give Slow Jet try think youll agree extra care weve given reallyCARL GOLDBERG does makeabigMODELS INC difference about dozen models manufactured Andreas necessarily cheap again arent kits market fiberglass finish best tradition type construction As stated previously latest radio equipment presented Paul Hoisten Bob Renaud Pete Waters Mark Stidham interesting presentation safety aspects cross-country fly ing stressing safety chase vehi cle its occupants An F3B question answer session covered just about aspect topic lighter side Dave Batey Milwaukee Thermal Soar ers showed above-average film ther mal soaring filmed Super-8 camera mounted atop Sailplane rounded out two-day session show-and-tell MARCS style weekend well spent So club looking different kind club project look what MARCS did After last time 80 modelers got together two daysand went home still talking another Good lift Dan Pruss 131 F Pennington Ln Plainfield IL 60544 RC Aerobatics/Van Putte Continued page 49 add thats another story recently came across bottle Wilhold glue misplaced back cupboard left several years separated top part darkcolored very thin consistency bottom layer appeared about right color thick could barely get piece A2 music wire through tried stir through top remembered heat makes glues watery put bot tle top microwave oven ran 30 seconds stirred did same routine several times until glue quite warmand thoroughly mixed procedure doesnt seem have affected its gluing ability Id interested hearing anyone about reasons what did polymer chemist perhaps Meanwhile plan see what happens leaving can see making trial glue joints periodically enjoyment RC augmented regu larly large envelope stuffed RC-oriented club newsletters arrives AMA HQ last batch came across two items general interest first May1985 147 V I j 1 Use CG X-Cel for-S controlled accel eration Slow Jet Youll get rockhard crystal-clear applications Slow Jet available squeezable clogresistant half-ounce one-ounce twoounce boffles MADE RU SA C 1985 CARL GOLDBERG MOUINC Introducing Slow Jet extra-thick CA glue Carl Goldberg 4735 WEST CHICAGO AVE CHICAGO IL 60651 Want REP-UP Pieps Average luveutory 4900 Prep! Over SD Sizes A/I Eveuts New Aheut Custen Tuned Engines P Coabat Raciag Free Flight 6 Sport Ceaupetitien Accessories 6 Parts Pp/eu Raciug Pattera 6 Sport FA 6 U/C Nag laveutery! Specialists Custom Ce ZD 6 Reed Eugiaes Std 6 R/C Custom Parts Ce Engines Complete lnveutorp 0 ludividual Stock Parts Curreat ZD 6 Medal/iou Eugines Maup New Parts Discontirnied ox Engines Rep/ku Owick 23 29 64 Engines /gnitioa Engiuc Accessories Visa 6 MasterCard Welcome Detailed Drochure Scud 751 Kustom Kratsmauship RD lox 29D Laguna Ni/Is CA 325 Ph 7141395162 discussed quite few club newsletters subject noise mufflers Most about necessity improve noise situation using better mufflers Almost club Ive involved last 15 years least formal muffler rule Some quite specific Nowadays almost everyone uses mufflers engines However middle Sixties almost nobody used Engines loud muffler propo nents claimed use mufflers would guarantee against loss fly ing field due noise problems early mufflers did lot quiet engines expense losing lot power Modern mufflers good job reduc ing noise sacrificing power remember thinking time club Western Ohio Radio Kontrol Socie ty required use mufflers about 1967 question time before everyone would forget what like before started using mufflers noise complaints would start again As know situation upon us As much hate think unless dra matic new improvements made mufflers two-cycle engines lot flying fields will lost other alternative can see clubs noise problems ban two-cycle engines favor four-cycle engines thats done wonder long will take flying field neighbors forget before four-cycle engines required start complaining again second item Id like share club newsletters pub lished Mount Rainier Radio Con trol Society Newsletter Tacoma WA Its semi-anonymous author Bill D wrote Old Threat Finally Identified Field Psychologist Glitchus Crashemup commonly known glitch has finally identified after years research dread malady preys upon certain segment species Homo Sapiens known RC Pilots normally lurking open fields grown men play model air craft glitch very dangerous full plumage adult male should approached experienced glitch hunters wielding loaded field strength meters has bite produces im mediate reactions beginning ner vous shaking twitching thumbs sequence symptoms often followed cries dont have Splintering thudding noises occur almost immediately point vic tim usually lapses depression may become militant approached next few minutes glitch invisible real imagined experience enemy should reported immediate ly field psychologist Ron Van Putte 111 Sleepy Oaks Rd Ft Walton Beach FL 32548 RC Electrics/Kopski Continued page 51 Cd will under charge eventually reach voltage its terminals equal about 15 x 6 about nine volts since Ni-Cds float up 15 volts per cell under charge take source volt age auto battery 12 volts avail able circuit voltage simply three volts difference 12 nine volts voltage appears across charging circuit resistance ear lier lessons circuit current charg ing current established choosing suitable resistor charge system design has plenty resistors choose Lets figure out make choice Last month saw several ways write Ohms Law Youll remember law relates three common elec trical terms voltage V current resistance R particular saw resistance can found dividing available circuit voltage ACV cir cuit current like R As example lets say six-cell pack made up 800 MAh cells Three amps very good charge current use 148 Model Aviation -I A monthly publication covering International RC Soaring Scene $1 6/yr US Canada & Mexico $24/yr elsewhere via airmail Post Office Box 269 Peterborough NH 03458