TODAY shortest day year Its last chance evening flying tonight clocks go back hour hereafterfor what seems like foreverflying confined weekends cause simply gets too dark too early Well thats entirely true us night-flyin folks know may sound like its some thing can easily donebut Its actu ally very easy least planes fairly docile unsurprising easiest-to-fly safest night fliers Glider configuration Old-Timers honest trainers Just some thing ponder future Last month promised neat photo sequence first ducted-fan Electric Ive seen three subject photos included herein modeler Bob Rumsey regular attendee KRC Electric fly model old Kyosho design called Cosmos originally designed RK2O ducted fan driven wet power intended jet trainer has duct sit ting top V-type tail Bob lightened up considerably omitting landing gear wing tip stabilizers etc de spite heavy Electric installation about lb lighter original intent All-up weight about 54 oz 60-in wing pro viding about 3 sq ft area Power Astro 15 cobalt 14 800-mAh cells fan experimental Hobby Lobby item originally designed 60-size wet power plant Bob cut blades down 4/2-in diame ter oniy using three original six Blade pitch adjustable currently set about 21-amp draw battery power al location handled Jomar SC-4 speed control does fly YES first launch hand proved inadequate force attain necessary initial flying speed second high-start assist courtesy Keith Shaw did fly up away remember flight live just watched videotape short ago courtesy Lynton Younger Willoughby OH complete video camera As Ive said times meet brings em out Nice work Bob Yet another Ainptique derivative shown month modeler Tom Williamson Collegeville PA Tom decided add per sonal touch fine kit turning fuselage upside down sorta Actually Tom bit scientific whatever result low-wing Amptique see herein flew its checkout flightwhich lasted about 25 sec before motors plastic reduction gear assembly gave upand quick turn land low altitude made very ner vous because what looked like shallow dihe dral everything worked out OK Tom changed Astro 4046 gear boxthe Ive recommendingand plane its sec ond checkout flight few days later Report The plane flies bit great looks looks beautiful Nice work Tom Hey people photos Amp tique derivatives Two neat ideas show up same photo Dave 38 Model Aviation Radio Cono Electrics Bob Kopski 25 st End Dr Lansdale PA 19446 bound happen Meres Bob Humseys Electric ducted-tan plane modilled Kyosflo Cosmos kit powered Astro 15 cobalt Photo Below L shows Keith Shaw releasing hi-start-assisted launch pure hand-launch didnt give enough initial speed Ily 88 KRC Electric Fly Other photo shows modified fan blades cut 6 3 shortened duct made 2 layers thin ply 1/8-in ply ring formers Stators hold rolled-ply motor tube hurt ot Indiana PA let snap mis pooto unoer hatch new geared Astro 25-powered sport job What may clear pix motor attached Look ma no clamps motor glued Well its really glued Dave used clear silicone adhesive adhere motor ply wood plate latter held bearers screws whole idea behind twofold quietness soft mount Dave demonstrated mounting method significantly lowered motor really gear noise typifies geared Electrics What noisy Electric same time mounting technique tends Futabas new Electric Professor Kopski says its excellent flier just doesnt want come down Motor 540-size geared special prop Recommended battery 6cell although used 7 Best check availability replacement props/parts though dampen some always present vibration Dave vexy proud ideaas well should thats Didja notice greatlooking airacoops photo Neat huh Doncha just wonder make ones just like em Wonder no Dave tells sleek scoops nothing plastic table ware spoons course theyve trimmed down shown Next time go toss party picnic waste away make sure think twice Nice work Dave Now whats nonsense about noisy Elec trics Well youve probably heard sound geared Electric Its noticeably noisy direct drives Ive heard some pretty loud directs too latter gen erally small-propped high-rpm ones sorta whine Anyway vote consistently noisy Electrics gear drives noisy Would believe just 2 dB sound level quieter certain wet four-strokers Now thats downright threatening embarrassing thanks George Poos Ft Washington PA sound-level-meter info Daves idea may have happened just time us quiet guys re tain lowest power noise titie So much lighter side months col umn Now want get little technical direct ing attention recent issue Model Builder magazine November 88 issue Electric columnist Mitch Poling includes some considerable discussion simple mathematical relationships describing operation Elec tric motors turn5 Out both Mitch columnist benefactors input reader Ed Westbrook Chelmsford MA Ed obvi ously has strong technical background applied abilities some info appeared col umn July August 88 issues Continued page 149 SUCKER-KIT manually controlled vacuum bag system makes lay up process combination foam & skins trouble free fast first time SUCKER-KIT ...$5995 VHS Show & Tell Video$3995 Add $400 shipping & handling MI residents add 4O/ sales tax Send $100 SASE product list samples real wood veneer skins Product List Includes Gapless Arrow Shaft Hinges Carbon Tow Mylar Sheet High-Tech items Dealer Inquires Welcome SEND CHECK OR MONEY ORDER TO Box 866 Lapeer Ml 48446 313 664-3330 B&P Associates Gives Total Flight Line FREEDOM battery needs call write B&P Associates PO Box 22054 Waco TX 76702-2054 817662-5587 new electric starter battery pack cuts cord has always tied starter power panel Discover freedom being able start plane wherever added safety less wire get caught prop charge hefty 4 Amp/hour pack will take through weekend flying power enough spare dont stop have Ni-Cads virtually size imaginable cut experimenter free design whatever takes make yours best setup field February 1989 39 Tom Williamsons unnamed low-wing ver sion Leisure Amptique flies well Kopski would feel better tad dihedral Leisure LT-50 motor turns As tro gearbox uses seven BOO-mAh Ni-Cd cells Jomar SC-S speed control Two excellent new ideas turn up Dave Burts new sport design Geared 25 cobalt held plywood plate silicone rubber adhesive Plate screwed mount plane really quietens noise gear drivel Neat airscoops fabricated plastic picnic spoons NO MORE KICKBACKS THROWN PROPS popular best selling odd-on ignition system world convert engine spark ignition breakerless capacitive discharge ignition System can installed engines 60 up both 2 8 4 stroke both single & twin cylinders 4strokers run absolutely beautiful ignition 10 30% power 4utroke engine No kickbick throwing props Absolutely no predetonatioi deetl 4stroke engines Much lower priced fuel & no rusty hearings commercl fuel availeble Red-Mis Very low 9001000 rEp reliable idle easy hand starts yma can control ignition timing will stop pro-detonation engine will run mudi cooler develop power Now available conylefely shielded spork plug lied 90 plug cover Chosen T&G Mfg n Originals its outstanding reliability Send $1 00 price list newsletter ordering Box 1732 RIVOIONr WY 82501 307 857-6897 CH Electronics Inc TOLED THIRTY-FIFTH ANNUAL RADIO CONTROL EXPOSITION TOLEDO SPORTS ARENA ONE MAIN STREET TOLEDO OHIO ADVANCED TICKETS may ordered sending selfaddressed stamped business size 4Vax9 envelope TICKETS 38235 Castle Romulus Ml 48174 orders above 5 tickets must include extra postage US orders must include 25 centsper order handling charge foreign orders must include 50 cents per order handling charge need send addressed envelope will provide necessary postageExpress Mail Orders Will Accepted Include check money order US funds made payable Weak Signals R/C Club Ticket prices $400 per day adults $1 00 per dayfor children 12 under Please specify number Deadline ticket orders March 31 1989 sales final non-refundable TICKETSAREALSOAVAILABLEAT THE DOOR Exposition information available contacting Wayne Yeager co-director ticket address phone 313 941-6661 Bring latest completely finished models display enter competition exciting awards R/C radios will awarded first second third place winners following classes NON-MILITARY SPORT SCALE PLANE AMA Rules MILITARY SPORT SCALE PLANE AMA Rules PRECISION SCALE PLANE AMA Rules PATTERN PLANE SPORT MONO-PLANE non-scale models SPORT BI-PLANE non-scale models OLD TIMER FREE FLIGHT R/C ASSIST R/C SAILPLANE non-scale models No Engines HELICOPTER R/C CAR COMPETITION BOAT MILITARY SCALE BOAT PLEASURE POWER BOAT WORKING VESSEL-UNARMED models entered competition will judged Best Finish Best MonoKote Directors Award Best Show Come join us enjoy yourselves unquestionably worlds greatest radio control model show will have traditional Swap Shop Saturday Night Auction Open public three great days APRIL 7 8 9 1989 FRIDAY9am to6pm SATURDAY9amto6pm SUNDAY9 am 430 pm presented Weak Signals R/C Club Toledo Ohio crystals explained last month Airtronics Fu taba arent making interchangeable crystals avail able products Now know rest story what think should done about channels Dont tell write AMA dis trict VP can tell George sent HAPPY NEW YEAR Schuemann WinglCarr Continued page 37 fore reducing wings drag essentially way reduce overall drag best accomplished using fully sheeted wing modified Atrix model shown photos rib/spar built-up structure wing could have made sheeted foam No matter what material inside goal make glass-smooth surface still strong enough withstand hard launches keeping goal airfoil should chosen will yield good compromise between thermaling speed requirements Several Eppler Selig airfoils clearly top choices No matter use reduction drag inherent Schuemann planform will increase wings performance Nearly high-speed powered aircraft use wings tapered root tip Sailplanes other hand generally use constant chord partway tip increase strength Schuemann wing used Discus modified Atrix con stunt chord about half span out tip leading edge swept back intervals about 40% 20% 10% modified Atrix wing diagram indi cates exact proportions used tip latest Discus design employs mild up turn trailing edge similar old Aquila model Sailplane tip chord small however doubt upsweep really has much effect center pres sure airfoil blurred since moves aft progressively toward tip retards noticeable step some airfoils like Eppler 205 exhibit effect rather forgiving ship less touchy elevator same 205 airfoil double-tapered wing very nice windy weather light lift may flying hard edge envelope As sweptwing aircraft center-of-gravity CU needs further aft would straight wing modified Atrix will unflyable center-of-gravity 25% root chord becomes very civ ilized CU back 33% 35% Utilizing planform also has addi tional advantage Sailplane straight wing ballasting becomes necessary windy conditions make model able penetrate Herk Stokelys Soaring col umn2 states really need crease airspeed about half wind speed get decent penetration prob lem ballast remains airplane during entire flight model using clean low-drag Schue mann wing will have higher average unbal lasted speed still working light lift landing slowly planform can fly unballasted others loading up add weight search far downwind gale winds still make back landing circle As full-size Discus will have no trouble picking out Sailplane gaggle will probably highest flying several times faster oth ers working lift no else can reach References 1 Spackman Elliot Schuemann Wing Planform RIG Soaring Digest July 1988 2 Herk Stokely Flying Models magazine September 1988 Note ATRIX plans Model Aviation magazine December 1986 issue RC Electrics/Kopski Continued page 39 issues t offered some motor/prop/power/rpm data cobalt 05s Continued page 153 February 1989 149 RC Electrics/Kopski Continued page 149 iSs UGH despicable meaning less motor descriptions again Small world Nowwhats about deeply interested Elec tric stuff works beyond just finding out what mo tor use strongly encourage dig up magazines mentioned above see what good ies await discovery effect references describe some detail fi4lly characterize motors some simple measurementsor someone elses dataso can easily choose motor/battery/prop/power/rpm formation next Electric project insight afforded can scientifically enjoy wondrous Electric model power worlda world key element model doms future Sometime future will go matter column cannot access ref erences given above meantime please try dig up info referenced Beyond sug gest find following additional references 1 About Electric Sport Scale Keith Shaw Model Builder July 1987 2 About ElectricsPart Eight columnist Model Aviation April 1984 might also comment Mr Westbrook has utilized July/August data Ive several letters favor able comment So look such data motors etc future always try react incoming mail Ive said before column often guided what readers write An Electric ARE ARF almost-ready-to-fly flies very well Professor foamy 05-power Theres darned incompre hensible designator again hate sizeand pretty opportunity check out fel low club member qulte impressed Professor uses geared Mabuchi 540 cansize motor turns unusual prop Whats un usual prop threads onto output gear drive shaft special item Im sure availability either spare props other spare plane parts factor careful consideration youre thinking buying because nonbalsa planes can diffi cult repair youre interested sort plane consider fair must include fact sample Professor flew equipped seven 1 2-Ah cells instead recommended six used Astro speed control cannot say well regular six-cell-powered example would perform Anyway plenty go handied extremely well As equipped flights honest eight-tonine-minute range routine large flatbottomed wing easily handied 48-oz all-up load intended delve some technical ex perience particular plane lost notes What wanted describe flight particular wherein specifically wanted test Rule Thumb described Model Aviation reference given previously April 1984 article gave guideline amount power needed just cruise Electrics goes like Motor Power Input Cruise Watts l Weight lb x Wing Loading oz/sq ft Knowing models weight wing area 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order amount charge put battery should allow predict flight time under cruise conditionsie just maintaining level fight conditions relatively easy task Electric speed control Now data Well can tell pre dicted time came out within few seconds actual timeessentially dead-on Now know some would interested facts figures come across Ill include info future column perhaps can re peat test now another example Last issue made reference resurrected Exciter 40-size aerobatic photo see October 85 issue MA semisymmetrical-airfoiled NACA 2412 low-winger powered cobalt 40 18 12-Ab cells All-up weight 89 oz wing planform 10 x 60 600 sq basic info get Calculated Motor Power Input Cruise Watts 6 x 891600/144 556 lb x 2136 oz/sq ft about 119 watts question now long can described battery supply 119 watts course depends much charge battery ie amp-minutes pumped charged up set charge current constant 44 amps charged 15 mm Thats total 66 ampere-minutes Dur ing discharge under cruise conditions current drain relatively low fact current will approximately watts/voltage about 119/12 x 18 5 amps relatively low current average cell voltage during dis charge will close classic 12-volt value above can now calculate availNow fliers over world have neat inexpensive functional way protect R/C transmitters dirt dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus GeorgIa 31904 404/323-2787 9am-Spm EST able watt-minutes battery can deliver Typi cally Ni-Cd will deliver about 95% charge pumped Taking account could expect about 12 x 18 x 66 x 95 1354 watt-minutes calculated required power level 119 watts sustain cruise might therefore expect about 1354/119 114 minutes flight So what actual flight time attained Would believe 12 mm 10 sec Folks thats shabby Im convinced rule thumb pretty good nearly perfect Professor example described pretty good case variance plus side As addenda very next flight Ex citer wide open flew field perimeter more-or-less constant altitude full power time 4 mm 25 sec So what normal flight time Ex citer normal flight consists taxi/takeoff rolls inside loops square insides outside loops stall turns snaps touch-and-goes Cuban eights etc tallied up log 30 typical flights represented total time 1872 minutes average ffight time 6 mm 15 sec Folks thats lot good flyin Whats secret word speed control use power needed maneuver under way no back off throttle Im moving get position open er up needed Think power management youre using speed control plane could benefit suggest give try As Ive written previously speed control adds just dimension fun Electric Electric fun enough An observation year has much like other year During past month inFebruary 1989 153 7KANS-COVER New Rocket Uses B C andO Engines5. Capability No Else Offers MRCs recent introduction 25 Moonbiaster inter mediate kit brings yet another technological advance MRCs Computer Aided Designs CAD built carry B4-2 06-3 engines However Moonblaster also commercially sold rocket kit includes easy-touse adapter also allows use powerful Dengines Bulitto take blast Moonblaster features large die-cut balsa fins blowmolded nose cone superb space capsule detailing Self stick decals 18chute Send free catalog See full line advanced MRC rockets hobby dealer cant help call us directly MRCG Model Rectifier Corporation 2500 Woodbridge Ave Edison NJ 08817 201 985-7800 coming mail has low think reason twofold First time between sues ie between Nats November issue no columns December issue normal col umns Also major parts country its fall pre-winter So outa-sight outa mind effect seeing column month combined season speculate lowers reader interest past weeksince December issue hit streetsthe mail back love Reflecting season issue will no doubt hands just about holiday time timely opportunity wish happy safe memorable holiday Andfor coming yearplease have noth ing happy safe quiet Electric landings Thank everyone giving opportu nity afforded column share fun Please forward comment question SASE please want reply author address given very top column RC AerobaticsNan Putte Continued page 41 elementary school librarian last item Henry Ham 251 Calle Canon de Faber Green Valley AZ 85614 wrote need help can test data Clark Y airfoil Reynolds numbers greater 87000 ob tamed has found data Reynolds num ber source 10-in chord Reyn olds number 87000 corresponds 12 mph Data 300000 would better can remember some old NACA reports Twenties Thirties covered wind tunnel tests Clark Y cant remember Reynolds number source anymore anyone can help Henry please write him Editors note sent copy Ron s column comments new Carl Goldberg Models kits manufacturer company could aware good not-so-good things said about mew models provide opportunity comment Noted flier Dave Patrick responded behalf com pany following being substance views Vector model has flown extensively K&B Sportster 45 OS 3SFP both using muffler pressure pressurize fitel tank recommended instruction booklet out fidel feed problem Dave recommended moving servo end steering pushrod hale closer servo shaft servo output arm/disc steering found too sensitive rather replace kits nose wheel steering arm longer unit Eagle 2 Dave expressed surprise kind balsa sample kit far off desired grade believes Carl Goldberg Models has quality controls among best indus try Concerning power plant feels strongly sport 40 engine racing engine too much airplane especially take offs made grass surface RMcM RC Scale/Wischers Continued page 43 few pencil lines will suffice Anyone thinking about flying all-metal Ford Trimotor Brace wires Streamlined wires flight surfac es Scale models have simulated vari ous meansor sometimes entirely eliminated Some modelers have gone great lengths make wires true miniature renditions actual shape rolled wires full-sized aircraft quite complete machine shop con junction expert machinists know-how becomes necessity anyone taking route best have seen made Merritt Zim merman pair hardened rollers having semielliptical shape peripheries equipped handcrank squeeze wire round stock streamlined shape Its tricky process expert because wire stretches being rolled its initial length must somewhat less fin ished product past have described own process using three parallel music wire lengths sol dered together filed sanded streamlined shape look great suffi ciently stiff prevent sagging small tension spring used end latest method manufacture called attention John Bishop visited bike shop found stainless steel bicycle spokes Racing cyclists use reduce drag rap idly revolving wheel come limited range lengths problem being sizes closely grouped around 12 fit stan dard racing wheels small variations length due fact some wheels laced spoke crossing three four other spokes also accommodate variations hub diameters full length spoke isnt flattened streamlined shape useful small aircraft brace wires tail surfaces advantages bike spoke end threaded 2-56a very common size Most Scale modelers have nuts threading taps #11 BIadesE~ 1i 40 Pad $485 Dehvered 100 Pad $895 Berkeley Trading CoCAEMO PO Box 26 Berkeley Springs WV 254112J Send 55on nor complete line 154 Model Aviation WORmS orocest SCALE E,oro seRVICE 800 000 RACKS PLANS 3 VIEWS PHOTO-PACKS PLANS ENLARGING 5ASE Enlarging Wt Jin Pepinon Catalog *OOSCALE PLANS ad PHOTO SEH VICE 3209 Madoon Geennbno NC 27403 psoe i1519l2925239 No cnIlocrl sioo BIIE5UDP EL IlL RIDOE iaIog MACHINERY TOOL 8 P0 Box 536-V omoog icane wv 25526 off Er 304-562-3538 complete selecnion lathes mills nools Aviation Modeler
Edition: Model Aviation - 1989/02
Page Numbers: 38, 39, 149, 153, 154
TODAY shortest day year Its last chance evening flying tonight clocks go back hour hereafterfor what seems like foreverflying confined weekends cause simply gets too dark too early Well thats entirely true us night-flyin folks know may sound like its some thing can easily donebut Its actu ally very easy least planes fairly docile unsurprising easiest-to-fly safest night fliers Glider configuration Old-Timers honest trainers Just some thing ponder future Last month promised neat photo sequence first ducted-fan Electric Ive seen three subject photos included herein modeler Bob Rumsey regular attendee KRC Electric fly model old Kyosho design called Cosmos originally designed RK2O ducted fan driven wet power intended jet trainer has duct sit ting top V-type tail Bob lightened up considerably omitting landing gear wing tip stabilizers etc de spite heavy Electric installation about lb lighter original intent All-up weight about 54 oz 60-in wing pro viding about 3 sq ft area Power Astro 15 cobalt 14 800-mAh cells fan experimental Hobby Lobby item originally designed 60-size wet power plant Bob cut blades down 4/2-in diame ter oniy using three original six Blade pitch adjustable currently set about 21-amp draw battery power al location handled Jomar SC-4 speed control does fly YES first launch hand proved inadequate force attain necessary initial flying speed second high-start assist courtesy Keith Shaw did fly up away remember flight live just watched videotape short ago courtesy Lynton Younger Willoughby OH complete video camera As Ive said times meet brings em out Nice work Bob Yet another Ainptique derivative shown month modeler Tom Williamson Collegeville PA Tom decided add per sonal touch fine kit turning fuselage upside down sorta Actually Tom bit scientific whatever result low-wing Amptique see herein flew its checkout flightwhich lasted about 25 sec before motors plastic reduction gear assembly gave upand quick turn land low altitude made very ner vous because what looked like shallow dihe dral everything worked out OK Tom changed Astro 4046 gear boxthe Ive recommendingand plane its sec ond checkout flight few days later Report The plane flies bit great looks looks beautiful Nice work Tom Hey people photos Amp tique derivatives Two neat ideas show up same photo Dave 38 Model Aviation Radio Cono Electrics Bob Kopski 25 st End Dr Lansdale PA 19446 bound happen Meres Bob Humseys Electric ducted-tan plane modilled Kyosflo Cosmos kit powered Astro 15 cobalt Photo Below L shows Keith Shaw releasing hi-start-assisted launch pure hand-launch didnt give enough initial speed Ily 88 KRC Electric Fly Other photo shows modified fan blades cut 6 3 shortened duct made 2 layers thin ply 1/8-in ply ring formers Stators hold rolled-ply motor tube hurt ot Indiana PA let snap mis pooto unoer hatch new geared Astro 25-powered sport job What may clear pix motor attached Look ma no clamps motor glued Well its really glued Dave used clear silicone adhesive adhere motor ply wood plate latter held bearers screws whole idea behind twofold quietness soft mount Dave demonstrated mounting method significantly lowered motor really gear noise typifies geared Electrics What noisy Electric same time mounting technique tends Futabas new Electric Professor Kopski says its excellent flier just doesnt want come down Motor 540-size geared special prop Recommended battery 6cell although used 7 Best check availability replacement props/parts though dampen some always present vibration Dave vexy proud ideaas well should thats Didja notice greatlooking airacoops photo Neat huh Doncha just wonder make ones just like em Wonder no Dave tells sleek scoops nothing plastic table ware spoons course theyve trimmed down shown Next time go toss party picnic waste away make sure think twice Nice work Dave Now whats nonsense about noisy Elec trics Well youve probably heard sound geared Electric Its noticeably noisy direct drives Ive heard some pretty loud directs too latter gen erally small-propped high-rpm ones sorta whine Anyway vote consistently noisy Electrics gear drives noisy Would believe just 2 dB sound level quieter certain wet four-strokers Now thats downright threatening embarrassing thanks George Poos Ft Washington PA sound-level-meter info Daves idea may have happened just time us quiet guys re tain lowest power noise titie So much lighter side months col umn Now want get little technical direct ing attention recent issue Model Builder magazine November 88 issue Electric columnist Mitch Poling includes some considerable discussion simple mathematical relationships describing operation Elec tric motors turn5 Out both Mitch columnist benefactors input reader Ed Westbrook Chelmsford MA Ed obvi ously has strong technical background applied abilities some info appeared col umn July August 88 issues Continued page 149 SUCKER-KIT manually controlled vacuum bag system makes lay up process combination foam & skins trouble free fast first time SUCKER-KIT ...$5995 VHS Show & Tell Video$3995 Add $400 shipping & handling MI residents add 4O/ sales tax Send $100 SASE product list samples real wood veneer skins Product List Includes Gapless Arrow Shaft Hinges Carbon Tow Mylar Sheet High-Tech items Dealer Inquires Welcome SEND CHECK OR MONEY ORDER TO Box 866 Lapeer Ml 48446 313 664-3330 B&P Associates Gives Total Flight Line FREEDOM battery needs call write B&P Associates PO Box 22054 Waco TX 76702-2054 817662-5587 new electric starter battery pack cuts cord has always tied starter power panel Discover freedom being able start plane wherever added safety less wire get caught prop charge hefty 4 Amp/hour pack will take through weekend flying power enough spare dont stop have Ni-Cads virtually size imaginable cut experimenter free design whatever takes make yours best setup field February 1989 39 Tom Williamsons unnamed low-wing ver sion Leisure Amptique flies well Kopski would feel better tad dihedral Leisure LT-50 motor turns As tro gearbox uses seven BOO-mAh Ni-Cd cells Jomar SC-S speed control Two excellent new ideas turn up Dave Burts new sport design Geared 25 cobalt held plywood plate silicone rubber adhesive Plate screwed mount plane really quietens noise gear drivel Neat airscoops fabricated plastic picnic spoons NO MORE KICKBACKS THROWN PROPS popular best selling odd-on ignition system world convert engine spark ignition breakerless capacitive discharge ignition System can installed engines 60 up both 2 8 4 stroke both single & twin cylinders 4strokers run absolutely beautiful ignition 10 30% power 4utroke engine No kickbick throwing props Absolutely no predetonatioi deetl 4stroke engines Much lower priced fuel & no rusty hearings commercl fuel availeble Red-Mis Very low 9001000 rEp reliable idle easy hand starts yma can control ignition timing will stop pro-detonation engine will run mudi cooler develop power Now available conylefely shielded spork plug lied 90 plug cover Chosen T&G Mfg n Originals its outstanding reliability Send $1 00 price list newsletter ordering Box 1732 RIVOIONr WY 82501 307 857-6897 CH Electronics Inc TOLED THIRTY-FIFTH ANNUAL RADIO CONTROL EXPOSITION TOLEDO SPORTS ARENA ONE MAIN STREET TOLEDO OHIO ADVANCED TICKETS may ordered sending selfaddressed stamped business size 4Vax9 envelope TICKETS 38235 Castle Romulus Ml 48174 orders above 5 tickets must include extra postage US orders must include 25 centsper order handling charge foreign orders must include 50 cents per order handling charge need send addressed envelope will provide necessary postageExpress Mail Orders Will Accepted Include check money order US funds made payable Weak Signals R/C Club Ticket prices $400 per day adults $1 00 per dayfor children 12 under Please specify number Deadline ticket orders March 31 1989 sales final non-refundable TICKETSAREALSOAVAILABLEAT THE DOOR Exposition information available contacting Wayne Yeager co-director ticket address phone 313 941-6661 Bring latest completely finished models display enter competition exciting awards R/C radios will awarded first second third place winners following classes NON-MILITARY SPORT SCALE PLANE AMA Rules MILITARY SPORT SCALE PLANE AMA Rules PRECISION SCALE PLANE AMA Rules PATTERN PLANE SPORT MONO-PLANE non-scale models SPORT BI-PLANE non-scale models OLD TIMER FREE FLIGHT R/C ASSIST R/C SAILPLANE non-scale models No Engines HELICOPTER R/C CAR COMPETITION BOAT MILITARY SCALE BOAT PLEASURE POWER BOAT WORKING VESSEL-UNARMED models entered competition will judged Best Finish Best MonoKote Directors Award Best Show Come join us enjoy yourselves unquestionably worlds greatest radio control model show will have traditional Swap Shop Saturday Night Auction Open public three great days APRIL 7 8 9 1989 FRIDAY9am to6pm SATURDAY9amto6pm SUNDAY9 am 430 pm presented Weak Signals R/C Club Toledo Ohio crystals explained last month Airtronics Fu taba arent making interchangeable crystals avail able products Now know rest story what think should done about channels Dont tell write AMA dis trict VP can tell George sent HAPPY NEW YEAR Schuemann WinglCarr Continued page 37 fore reducing wings drag essentially way reduce overall drag best accomplished using fully sheeted wing modified Atrix model shown photos rib/spar built-up structure wing could have made sheeted foam No matter what material inside goal make glass-smooth surface still strong enough withstand hard launches keeping goal airfoil should chosen will yield good compromise between thermaling speed requirements Several Eppler Selig airfoils clearly top choices No matter use reduction drag inherent Schuemann planform will increase wings performance Nearly high-speed powered aircraft use wings tapered root tip Sailplanes other hand generally use constant chord partway tip increase strength Schuemann wing used Discus modified Atrix con stunt chord about half span out tip leading edge swept back intervals about 40% 20% 10% modified Atrix wing diagram indi cates exact proportions used tip latest Discus design employs mild up turn trailing edge similar old Aquila model Sailplane tip chord small however doubt upsweep really has much effect center pres sure airfoil blurred since moves aft progressively toward tip retards noticeable step some airfoils like Eppler 205 exhibit effect rather forgiving ship less touchy elevator same 205 airfoil double-tapered wing very nice windy weather light lift may flying hard edge envelope As sweptwing aircraft center-of-gravity CU needs further aft would straight wing modified Atrix will unflyable center-of-gravity 25% root chord becomes very civ ilized CU back 33% 35% Utilizing planform also has addi tional advantage Sailplane straight wing ballasting becomes necessary windy conditions make model able penetrate Herk Stokelys Soaring col umn2 states really need crease airspeed about half wind speed get decent penetration prob lem ballast remains airplane during entire flight model using clean low-drag Schue mann wing will have higher average unbal lasted speed still working light lift landing slowly planform can fly unballasted others loading up add weight search far downwind gale winds still make back landing circle As full-size Discus will have no trouble picking out Sailplane gaggle will probably highest flying several times faster oth ers working lift no else can reach References 1 Spackman Elliot Schuemann Wing Planform RIG Soaring Digest July 1988 2 Herk Stokely Flying Models magazine September 1988 Note ATRIX plans Model Aviation magazine December 1986 issue RC Electrics/Kopski Continued page 39 issues t offered some motor/prop/power/rpm data cobalt 05s Continued page 153 February 1989 149 RC Electrics/Kopski Continued page 149 iSs UGH despicable meaning less motor descriptions again Small world Nowwhats about deeply interested Elec tric stuff works beyond just finding out what mo tor use strongly encourage dig up magazines mentioned above see what good ies await discovery effect references describe some detail fi4lly characterize motors some simple measurementsor someone elses dataso can easily choose motor/battery/prop/power/rpm formation next Electric project insight afforded can scientifically enjoy wondrous Electric model power worlda world key element model doms future Sometime future will go matter column cannot access ref erences given above meantime please try dig up info referenced Beyond sug gest find following additional references 1 About Electric Sport Scale Keith Shaw Model Builder July 1987 2 About ElectricsPart Eight columnist Model Aviation April 1984 might also comment Mr Westbrook has utilized July/August data Ive several letters favor able comment So look such data motors etc future always try react incoming mail Ive said before column often guided what readers write An Electric ARE ARF almost-ready-to-fly flies very well Professor foamy 05-power Theres darned incompre hensible designator again hate sizeand pretty opportunity check out fel low club member qulte impressed Professor uses geared Mabuchi 540 cansize motor turns unusual prop Whats un usual prop threads onto output gear drive shaft special item Im sure availability either spare props other spare plane parts factor careful consideration youre thinking buying because nonbalsa planes can diffi cult repair youre interested sort plane consider fair must include fact sample Professor flew equipped seven 1 2-Ah cells instead recommended six used Astro speed control cannot say well regular six-cell-powered example would perform Anyway plenty go handied extremely well As equipped flights honest eight-tonine-minute range routine large flatbottomed wing easily handied 48-oz all-up load intended delve some technical ex perience particular plane lost notes What wanted describe flight particular wherein specifically wanted test Rule Thumb described Model Aviation reference given previously April 1984 article gave guideline amount power needed just cruise Electrics goes like Motor Power Input Cruise Watts l Weight lb x Wing Loading oz/sq ft Knowing models weight wing area 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order amount charge put battery should allow predict flight time under cruise conditionsie just maintaining level fight conditions relatively easy task Electric speed control Now data Well can tell pre dicted time came out within few seconds actual timeessentially dead-on Now know some would interested facts figures come across Ill include info future column perhaps can re peat test now another example Last issue made reference resurrected Exciter 40-size aerobatic photo see October 85 issue MA semisymmetrical-airfoiled NACA 2412 low-winger powered cobalt 40 18 12-Ab cells All-up weight 89 oz wing planform 10 x 60 600 sq basic info get Calculated Motor Power Input Cruise Watts 6 x 891600/144 556 lb x 2136 oz/sq ft about 119 watts question now long can described battery supply 119 watts course depends much charge battery ie amp-minutes pumped charged up set charge current constant 44 amps charged 15 mm Thats total 66 ampere-minutes Dur ing discharge under cruise conditions current drain relatively low fact current will approximately watts/voltage about 119/12 x 18 5 amps relatively low current average cell voltage during dis charge will close classic 12-volt value above can now calculate availNow fliers over world have neat inexpensive functional way protect R/C transmitters dirt dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus GeorgIa 31904 404/323-2787 9am-Spm EST able watt-minutes battery can deliver Typi cally Ni-Cd will deliver about 95% charge pumped Taking account could expect about 12 x 18 x 66 x 95 1354 watt-minutes calculated required power level 119 watts sustain cruise might therefore expect about 1354/119 114 minutes flight So what actual flight time attained Would believe 12 mm 10 sec Folks thats shabby Im convinced rule thumb pretty good nearly perfect Professor example described pretty good case variance plus side As addenda very next flight Ex citer wide open flew field perimeter more-or-less constant altitude full power time 4 mm 25 sec So what normal flight time Ex citer normal flight consists taxi/takeoff rolls inside loops square insides outside loops stall turns snaps touch-and-goes Cuban eights etc tallied up log 30 typical flights represented total time 1872 minutes average ffight time 6 mm 15 sec Folks thats lot good flyin Whats secret word speed control use power needed maneuver under way no back off throttle Im moving get position open er up needed Think power management youre using speed control plane could benefit suggest give try As Ive written previously speed control adds just dimension fun Electric Electric fun enough An observation year has much like other year During past month inFebruary 1989 153 7KANS-COVER New Rocket Uses B C andO Engines5. Capability No Else Offers MRCs recent introduction 25 Moonbiaster inter mediate kit brings yet another technological advance MRCs Computer Aided Designs CAD built carry B4-2 06-3 engines However Moonblaster also commercially sold rocket kit includes easy-touse adapter also allows use powerful Dengines Bulitto take blast Moonblaster features large die-cut balsa fins blowmolded nose cone superb space capsule detailing Self stick decals 18chute Send free catalog See full line advanced MRC rockets hobby dealer cant help call us directly MRCG Model Rectifier Corporation 2500 Woodbridge Ave Edison NJ 08817 201 985-7800 coming mail has low think reason twofold First time between sues ie between Nats November issue no columns December issue normal col umns Also major parts country its fall pre-winter So outa-sight outa mind effect seeing column month combined season speculate lowers reader interest past weeksince December issue hit streetsthe mail back love Reflecting season issue will no doubt hands just about holiday time timely opportunity wish happy safe memorable holiday Andfor coming yearplease have noth ing happy safe quiet Electric landings Thank everyone giving opportu nity afforded column share fun Please forward comment question SASE please want reply author address given very top column RC AerobaticsNan Putte Continued page 41 elementary school librarian last item Henry Ham 251 Calle Canon de Faber Green Valley AZ 85614 wrote need help can test data Clark Y airfoil Reynolds numbers greater 87000 ob tamed has found data Reynolds num ber source 10-in chord Reyn olds number 87000 corresponds 12 mph Data 300000 would better can remember some old NACA reports Twenties Thirties covered wind tunnel tests Clark Y cant remember Reynolds number source anymore anyone can help Henry please write him Editors note sent copy Ron s column comments new Carl Goldberg Models kits manufacturer company could aware good not-so-good things said about mew models provide opportunity comment Noted flier Dave Patrick responded behalf com pany following being substance views Vector model has flown extensively K&B Sportster 45 OS 3SFP both using muffler pressure pressurize fitel tank recommended instruction booklet out fidel feed problem Dave recommended moving servo end steering pushrod hale closer servo shaft servo output arm/disc steering found too sensitive rather replace kits nose wheel steering arm longer unit Eagle 2 Dave expressed surprise kind balsa sample kit far off desired grade believes Carl Goldberg Models has quality controls among best indus try Concerning power plant feels strongly sport 40 engine racing engine too much airplane especially take offs made grass surface RMcM RC Scale/Wischers Continued page 43 few pencil lines will suffice Anyone thinking about flying all-metal Ford Trimotor Brace wires Streamlined wires flight surfac es Scale models have simulated vari ous meansor sometimes entirely eliminated Some modelers have gone great lengths make wires true miniature renditions actual shape rolled wires full-sized aircraft quite complete machine shop con junction expert machinists know-how becomes necessity anyone taking route best have seen made Merritt Zim merman pair hardened rollers having semielliptical shape peripheries equipped handcrank squeeze wire round stock streamlined shape Its tricky process expert because wire stretches being rolled its initial length must somewhat less fin ished product past have described own process using three parallel music wire lengths sol dered together filed sanded streamlined shape look great suffi ciently stiff prevent sagging small tension spring used end latest method manufacture called attention John Bishop visited bike shop found stainless steel bicycle spokes Racing cyclists use reduce drag rap idly revolving wheel come limited range lengths problem being sizes closely grouped around 12 fit stan dard racing wheels small variations length due fact some wheels laced spoke crossing three four other spokes also accommodate variations hub diameters full length spoke isnt flattened streamlined shape useful small aircraft brace wires tail surfaces advantages bike spoke end threaded 2-56a very common size Most Scale modelers have nuts threading taps #11 BIadesE~ 1i 40 Pad $485 Dehvered 100 Pad $895 Berkeley Trading CoCAEMO PO Box 26 Berkeley Springs WV 254112J Send 55on nor complete line 154 Model Aviation WORmS orocest SCALE E,oro seRVICE 800 000 RACKS PLANS 3 VIEWS PHOTO-PACKS PLANS ENLARGING 5ASE Enlarging Wt Jin Pepinon Catalog *OOSCALE PLANS ad PHOTO SEH VICE 3209 Madoon Geennbno NC 27403 psoe i1519l2925239 No cnIlocrl sioo BIIE5UDP EL IlL RIDOE iaIog MACHINERY TOOL 8 P0 Box 536-V omoog icane wv 25526 off Er 304-562-3538 complete selecnion lathes mills nools Aviation Modeler
Edition: Model Aviation - 1989/02
Page Numbers: 38, 39, 149, 153, 154
TODAY shortest day year Its last chance evening flying tonight clocks go back hour hereafterfor what seems like foreverflying confined weekends cause simply gets too dark too early Well thats entirely true us night-flyin folks know may sound like its some thing can easily donebut Its actu ally very easy least planes fairly docile unsurprising easiest-to-fly safest night fliers Glider configuration Old-Timers honest trainers Just some thing ponder future Last month promised neat photo sequence first ducted-fan Electric Ive seen three subject photos included herein modeler Bob Rumsey regular attendee KRC Electric fly model old Kyosho design called Cosmos originally designed RK2O ducted fan driven wet power intended jet trainer has duct sit ting top V-type tail Bob lightened up considerably omitting landing gear wing tip stabilizers etc de spite heavy Electric installation about lb lighter original intent All-up weight about 54 oz 60-in wing pro viding about 3 sq ft area Power Astro 15 cobalt 14 800-mAh cells fan experimental Hobby Lobby item originally designed 60-size wet power plant Bob cut blades down 4/2-in diame ter oniy using three original six Blade pitch adjustable currently set about 21-amp draw battery power al location handled Jomar SC-4 speed control does fly YES first launch hand proved inadequate force attain necessary initial flying speed second high-start assist courtesy Keith Shaw did fly up away remember flight live just watched videotape short ago courtesy Lynton Younger Willoughby OH complete video camera As Ive said times meet brings em out Nice work Bob Yet another Ainptique derivative shown month modeler Tom Williamson Collegeville PA Tom decided add per sonal touch fine kit turning fuselage upside down sorta Actually Tom bit scientific whatever result low-wing Amptique see herein flew its checkout flightwhich lasted about 25 sec before motors plastic reduction gear assembly gave upand quick turn land low altitude made very ner vous because what looked like shallow dihe dral everything worked out OK Tom changed Astro 4046 gear boxthe Ive recommendingand plane its sec ond checkout flight few days later Report The plane flies bit great looks looks beautiful Nice work Tom Hey people photos Amp tique derivatives Two neat ideas show up same photo Dave 38 Model Aviation Radio Cono Electrics Bob Kopski 25 st End Dr Lansdale PA 19446 bound happen Meres Bob Humseys Electric ducted-tan plane modilled Kyosflo Cosmos kit powered Astro 15 cobalt Photo Below L shows Keith Shaw releasing hi-start-assisted launch pure hand-launch didnt give enough initial speed Ily 88 KRC Electric Fly Other photo shows modified fan blades cut 6 3 shortened duct made 2 layers thin ply 1/8-in ply ring formers Stators hold rolled-ply motor tube hurt ot Indiana PA let snap mis pooto unoer hatch new geared Astro 25-powered sport job What may clear pix motor attached Look ma no clamps motor glued Well its really glued Dave used clear silicone adhesive adhere motor ply wood plate latter held bearers screws whole idea behind twofold quietness soft mount Dave demonstrated mounting method significantly lowered motor really gear noise typifies geared Electrics What noisy Electric same time mounting technique tends Futabas new Electric Professor Kopski says its excellent flier just doesnt want come down Motor 540-size geared special prop Recommended battery 6cell although used 7 Best check availability replacement props/parts though dampen some always present vibration Dave vexy proud ideaas well should thats Didja notice greatlooking airacoops photo Neat huh Doncha just wonder make ones just like em Wonder no Dave tells sleek scoops nothing plastic table ware spoons course theyve trimmed down shown Next time go toss party picnic waste away make sure think twice Nice work Dave Now whats nonsense about noisy Elec trics Well youve probably heard sound geared Electric Its noticeably noisy direct drives Ive heard some pretty loud directs too latter gen erally small-propped high-rpm ones sorta whine Anyway vote consistently noisy Electrics gear drives noisy Would believe just 2 dB sound level quieter certain wet four-strokers Now thats downright threatening embarrassing thanks George Poos Ft Washington PA sound-level-meter info Daves idea may have happened just time us quiet guys re tain lowest power noise titie So much lighter side months col umn Now want get little technical direct ing attention recent issue Model Builder magazine November 88 issue Electric columnist Mitch Poling includes some considerable discussion simple mathematical relationships describing operation Elec tric motors turn5 Out both Mitch columnist benefactors input reader Ed Westbrook Chelmsford MA Ed obvi ously has strong technical background applied abilities some info appeared col umn July August 88 issues Continued page 149 SUCKER-KIT manually controlled vacuum bag system makes lay up process combination foam & skins trouble free fast first time SUCKER-KIT ...$5995 VHS Show & Tell Video$3995 Add $400 shipping & handling MI residents add 4O/ sales tax Send $100 SASE product list samples real wood veneer skins Product List Includes Gapless Arrow Shaft Hinges Carbon Tow Mylar Sheet High-Tech items Dealer Inquires Welcome SEND CHECK OR MONEY ORDER TO Box 866 Lapeer Ml 48446 313 664-3330 B&P Associates Gives Total Flight Line FREEDOM battery needs call write B&P Associates PO Box 22054 Waco TX 76702-2054 817662-5587 new electric starter battery pack cuts cord has always tied starter power panel Discover freedom being able start plane wherever added safety less wire get caught prop charge hefty 4 Amp/hour pack will take through weekend flying power enough spare dont stop have Ni-Cads virtually size imaginable cut experimenter free design whatever takes make yours best setup field February 1989 39 Tom Williamsons unnamed low-wing ver sion Leisure Amptique flies well Kopski would feel better tad dihedral Leisure LT-50 motor turns As tro gearbox uses seven BOO-mAh Ni-Cd cells Jomar SC-S speed control Two excellent new ideas turn up Dave Burts new sport design Geared 25 cobalt held plywood plate silicone rubber adhesive Plate screwed mount plane really quietens noise gear drivel Neat airscoops fabricated plastic picnic spoons NO MORE KICKBACKS THROWN PROPS popular best selling odd-on ignition system world convert engine spark ignition breakerless capacitive discharge ignition System can installed engines 60 up both 2 8 4 stroke both single & twin cylinders 4strokers run absolutely beautiful ignition 10 30% power 4utroke engine No kickbick throwing props Absolutely no predetonatioi deetl 4stroke engines Much lower priced fuel & no rusty hearings commercl fuel availeble Red-Mis Very low 9001000 rEp reliable idle easy hand starts yma can control ignition timing will stop pro-detonation engine will run mudi cooler develop power Now available conylefely shielded spork plug lied 90 plug cover Chosen T&G Mfg n Originals its outstanding reliability Send $1 00 price list newsletter ordering Box 1732 RIVOIONr WY 82501 307 857-6897 CH Electronics Inc TOLED THIRTY-FIFTH ANNUAL RADIO CONTROL EXPOSITION TOLEDO SPORTS ARENA ONE MAIN STREET TOLEDO OHIO ADVANCED TICKETS may ordered sending selfaddressed stamped business size 4Vax9 envelope TICKETS 38235 Castle Romulus Ml 48174 orders above 5 tickets must include extra postage US orders must include 25 centsper order handling charge foreign orders must include 50 cents per order handling charge need send addressed envelope will provide necessary postageExpress Mail Orders Will Accepted Include check money order US funds made payable Weak Signals R/C Club Ticket prices $400 per day adults $1 00 per dayfor children 12 under Please specify number Deadline ticket orders March 31 1989 sales final non-refundable TICKETSAREALSOAVAILABLEAT THE DOOR Exposition information available contacting Wayne Yeager co-director ticket address phone 313 941-6661 Bring latest completely finished models display enter competition exciting awards R/C radios will awarded first second third place winners following classes NON-MILITARY SPORT SCALE PLANE AMA Rules MILITARY SPORT SCALE PLANE AMA Rules PRECISION SCALE PLANE AMA Rules PATTERN PLANE SPORT MONO-PLANE non-scale models SPORT BI-PLANE non-scale models OLD TIMER FREE FLIGHT R/C ASSIST R/C SAILPLANE non-scale models No Engines HELICOPTER R/C CAR COMPETITION BOAT MILITARY SCALE BOAT PLEASURE POWER BOAT WORKING VESSEL-UNARMED models entered competition will judged Best Finish Best MonoKote Directors Award Best Show Come join us enjoy yourselves unquestionably worlds greatest radio control model show will have traditional Swap Shop Saturday Night Auction Open public three great days APRIL 7 8 9 1989 FRIDAY9am to6pm SATURDAY9amto6pm SUNDAY9 am 430 pm presented Weak Signals R/C Club Toledo Ohio crystals explained last month Airtronics Fu taba arent making interchangeable crystals avail able products Now know rest story what think should done about channels Dont tell write AMA dis trict VP can tell George sent HAPPY NEW YEAR Schuemann WinglCarr Continued page 37 fore reducing wings drag essentially way reduce overall drag best accomplished using fully sheeted wing modified Atrix model shown photos rib/spar built-up structure wing could have made sheeted foam No matter what material inside goal make glass-smooth surface still strong enough withstand hard launches keeping goal airfoil should chosen will yield good compromise between thermaling speed requirements Several Eppler Selig airfoils clearly top choices No matter use reduction drag inherent Schuemann planform will increase wings performance Nearly high-speed powered aircraft use wings tapered root tip Sailplanes other hand generally use constant chord partway tip increase strength Schuemann wing used Discus modified Atrix con stunt chord about half span out tip leading edge swept back intervals about 40% 20% 10% modified Atrix wing diagram indi cates exact proportions used tip latest Discus design employs mild up turn trailing edge similar old Aquila model Sailplane tip chord small however doubt upsweep really has much effect center pres sure airfoil blurred since moves aft progressively toward tip retards noticeable step some airfoils like Eppler 205 exhibit effect rather forgiving ship less touchy elevator same 205 airfoil double-tapered wing very nice windy weather light lift may flying hard edge envelope As sweptwing aircraft center-of-gravity CU needs further aft would straight wing modified Atrix will unflyable center-of-gravity 25% root chord becomes very civ ilized CU back 33% 35% Utilizing planform also has addi tional advantage Sailplane straight wing ballasting becomes necessary windy conditions make model able penetrate Herk Stokelys Soaring col umn2 states really need crease airspeed about half wind speed get decent penetration prob lem ballast remains airplane during entire flight model using clean low-drag Schue mann wing will have higher average unbal lasted speed still working light lift landing slowly planform can fly unballasted others loading up add weight search far downwind gale winds still make back landing circle As full-size Discus will have no trouble picking out Sailplane gaggle will probably highest flying several times faster oth ers working lift no else can reach References 1 Spackman Elliot Schuemann Wing Planform RIG Soaring Digest July 1988 2 Herk Stokely Flying Models magazine September 1988 Note ATRIX plans Model Aviation magazine December 1986 issue RC Electrics/Kopski Continued page 39 issues t offered some motor/prop/power/rpm data cobalt 05s Continued page 153 February 1989 149 RC Electrics/Kopski Continued page 149 iSs UGH despicable meaning less motor descriptions again Small world Nowwhats about deeply interested Elec tric stuff works beyond just finding out what mo tor use strongly encourage dig up magazines mentioned above see what good ies await discovery effect references describe some detail fi4lly characterize motors some simple measurementsor someone elses dataso can easily choose motor/battery/prop/power/rpm formation next Electric project insight afforded can scientifically enjoy wondrous Electric model power worlda world key element model doms future Sometime future will go matter column cannot access ref erences given above meantime please try dig up info referenced Beyond sug gest find following additional references 1 About Electric Sport Scale Keith Shaw Model Builder July 1987 2 About ElectricsPart Eight columnist Model Aviation April 1984 might also comment Mr Westbrook has utilized July/August data Ive several letters favor able comment So look such data motors etc future always try react incoming mail Ive said before column often guided what readers write An Electric ARE ARF almost-ready-to-fly flies very well Professor foamy 05-power Theres darned incompre hensible designator again hate sizeand pretty opportunity check out fel low club member qulte impressed Professor uses geared Mabuchi 540 cansize motor turns unusual prop Whats un usual prop threads onto output gear drive shaft special item Im sure availability either spare props other spare plane parts factor careful consideration youre thinking buying because nonbalsa planes can diffi cult repair youre interested sort plane consider fair must include fact sample Professor flew equipped seven 1 2-Ah cells instead recommended six used Astro speed control cannot say well regular six-cell-powered example would perform Anyway plenty go handied extremely well As equipped flights honest eight-tonine-minute range routine large flatbottomed wing easily handied 48-oz all-up load intended delve some technical ex perience particular plane lost notes What wanted describe flight particular wherein specifically wanted test Rule Thumb described Model Aviation reference given previously April 1984 article gave guideline amount power needed just cruise Electrics goes like Motor Power Input Cruise Watts l Weight lb x Wing Loading oz/sq ft Knowing models weight wing area 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order amount charge put battery should allow predict flight time under cruise conditionsie just maintaining level fight conditions relatively easy task Electric speed control Now data Well can tell pre dicted time came out within few seconds actual timeessentially dead-on Now know some would interested facts figures come across Ill include info future column perhaps can re peat test now another example Last issue made reference resurrected Exciter 40-size aerobatic photo see October 85 issue MA semisymmetrical-airfoiled NACA 2412 low-winger powered cobalt 40 18 12-Ab cells All-up weight 89 oz wing planform 10 x 60 600 sq basic info get Calculated Motor Power Input Cruise Watts 6 x 891600/144 556 lb x 2136 oz/sq ft about 119 watts question now long can described battery supply 119 watts course depends much charge battery ie amp-minutes pumped charged up set charge current constant 44 amps charged 15 mm Thats total 66 ampere-minutes Dur ing discharge under cruise conditions current drain relatively low fact current will approximately watts/voltage about 119/12 x 18 5 amps relatively low current average cell voltage during dis charge will close classic 12-volt value above can now calculate availNow fliers over world have neat inexpensive functional way protect R/C transmitters dirt dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus GeorgIa 31904 404/323-2787 9am-Spm EST able watt-minutes battery can deliver Typi cally Ni-Cd will deliver about 95% charge pumped Taking account could expect about 12 x 18 x 66 x 95 1354 watt-minutes calculated required power level 119 watts sustain cruise might therefore expect about 1354/119 114 minutes flight So what actual flight time attained Would believe 12 mm 10 sec Folks thats shabby Im convinced rule thumb pretty good nearly perfect Professor example described pretty good case variance plus side As addenda very next flight Ex citer wide open flew field perimeter more-or-less constant altitude full power time 4 mm 25 sec So what normal flight time Ex citer normal flight consists taxi/takeoff rolls inside loops square insides outside loops stall turns snaps touch-and-goes Cuban eights etc tallied up log 30 typical flights represented total time 1872 minutes average ffight time 6 mm 15 sec Folks thats lot good flyin Whats secret word speed control use power needed maneuver under way no back off throttle Im moving get position open er up needed Think power management youre using speed control plane could benefit suggest give try As Ive written previously speed control adds just dimension fun Electric Electric fun enough An observation year has much like other year During past month inFebruary 1989 153 7KANS-COVER New Rocket Uses B C andO Engines5. Capability No Else Offers MRCs recent introduction 25 Moonbiaster inter mediate kit brings yet another technological advance MRCs Computer Aided Designs CAD built carry B4-2 06-3 engines However Moonblaster also commercially sold rocket kit includes easy-touse adapter also allows use powerful Dengines Bulitto take blast Moonblaster features large die-cut balsa fins blowmolded nose cone superb space capsule detailing Self stick decals 18chute Send free catalog See full line advanced MRC rockets hobby dealer cant help call us directly MRCG Model Rectifier Corporation 2500 Woodbridge Ave Edison NJ 08817 201 985-7800 coming mail has low think reason twofold First time between sues ie between Nats November issue no columns December issue normal col umns Also major parts country its fall pre-winter So outa-sight outa mind effect seeing column month combined season speculate lowers reader interest past weeksince December issue hit streetsthe mail back love Reflecting season issue will no doubt hands just about holiday time timely opportunity wish happy safe memorable holiday Andfor coming yearplease have noth ing happy safe quiet Electric landings Thank everyone giving opportu nity afforded column share fun Please forward comment question SASE please want reply author address given very top column RC AerobaticsNan Putte Continued page 41 elementary school librarian last item Henry Ham 251 Calle Canon de Faber Green Valley AZ 85614 wrote need help can test data Clark Y airfoil Reynolds numbers greater 87000 ob tamed has found data Reynolds num ber source 10-in chord Reyn olds number 87000 corresponds 12 mph Data 300000 would better can remember some old NACA reports Twenties Thirties covered wind tunnel tests Clark Y cant remember Reynolds number source anymore anyone can help Henry please write him Editors note sent copy Ron s column comments new Carl Goldberg Models kits manufacturer company could aware good not-so-good things said about mew models provide opportunity comment Noted flier Dave Patrick responded behalf com pany following being substance views Vector model has flown extensively K&B Sportster 45 OS 3SFP both using muffler pressure pressurize fitel tank recommended instruction booklet out fidel feed problem Dave recommended moving servo end steering pushrod hale closer servo shaft servo output arm/disc steering found too sensitive rather replace kits nose wheel steering arm longer unit Eagle 2 Dave expressed surprise kind balsa sample kit far off desired grade believes Carl Goldberg Models has quality controls among best indus try Concerning power plant feels strongly sport 40 engine racing engine too much airplane especially take offs made grass surface RMcM RC Scale/Wischers Continued page 43 few pencil lines will suffice Anyone thinking about flying all-metal Ford Trimotor Brace wires Streamlined wires flight surfac es Scale models have simulated vari ous meansor sometimes entirely eliminated Some modelers have gone great lengths make wires true miniature renditions actual shape rolled wires full-sized aircraft quite complete machine shop con junction expert machinists know-how becomes necessity anyone taking route best have seen made Merritt Zim merman pair hardened rollers having semielliptical shape peripheries equipped handcrank squeeze wire round stock streamlined shape Its tricky process expert because wire stretches being rolled its initial length must somewhat less fin ished product past have described own process using three parallel music wire lengths sol dered together filed sanded streamlined shape look great suffi ciently stiff prevent sagging small tension spring used end latest method manufacture called attention John Bishop visited bike shop found stainless steel bicycle spokes Racing cyclists use reduce drag rap idly revolving wheel come limited range lengths problem being sizes closely grouped around 12 fit stan dard racing wheels small variations length due fact some wheels laced spoke crossing three four other spokes also accommodate variations hub diameters full length spoke isnt flattened streamlined shape useful small aircraft brace wires tail surfaces advantages bike spoke end threaded 2-56a very common size Most Scale modelers have nuts threading taps #11 BIadesE~ 1i 40 Pad $485 Dehvered 100 Pad $895 Berkeley Trading CoCAEMO PO Box 26 Berkeley Springs WV 254112J Send 55on nor complete line 154 Model Aviation WORmS orocest SCALE E,oro seRVICE 800 000 RACKS PLANS 3 VIEWS PHOTO-PACKS PLANS ENLARGING 5ASE Enlarging Wt Jin Pepinon Catalog *OOSCALE PLANS ad PHOTO SEH VICE 3209 Madoon Geennbno NC 27403 psoe i1519l2925239 No cnIlocrl sioo BIIE5UDP EL IlL RIDOE iaIog MACHINERY TOOL 8 P0 Box 536-V omoog icane wv 25526 off Er 304-562-3538 complete selecnion lathes mills nools Aviation Modeler
Edition: Model Aviation - 1989/02
Page Numbers: 38, 39, 149, 153, 154
TODAY shortest day year Its last chance evening flying tonight clocks go back hour hereafterfor what seems like foreverflying confined weekends cause simply gets too dark too early Well thats entirely true us night-flyin folks know may sound like its some thing can easily donebut Its actu ally very easy least planes fairly docile unsurprising easiest-to-fly safest night fliers Glider configuration Old-Timers honest trainers Just some thing ponder future Last month promised neat photo sequence first ducted-fan Electric Ive seen three subject photos included herein modeler Bob Rumsey regular attendee KRC Electric fly model old Kyosho design called Cosmos originally designed RK2O ducted fan driven wet power intended jet trainer has duct sit ting top V-type tail Bob lightened up considerably omitting landing gear wing tip stabilizers etc de spite heavy Electric installation about lb lighter original intent All-up weight about 54 oz 60-in wing pro viding about 3 sq ft area Power Astro 15 cobalt 14 800-mAh cells fan experimental Hobby Lobby item originally designed 60-size wet power plant Bob cut blades down 4/2-in diame ter oniy using three original six Blade pitch adjustable currently set about 21-amp draw battery power al location handled Jomar SC-4 speed control does fly YES first launch hand proved inadequate force attain necessary initial flying speed second high-start assist courtesy Keith Shaw did fly up away remember flight live just watched videotape short ago courtesy Lynton Younger Willoughby OH complete video camera As Ive said times meet brings em out Nice work Bob Yet another Ainptique derivative shown month modeler Tom Williamson Collegeville PA Tom decided add per sonal touch fine kit turning fuselage upside down sorta Actually Tom bit scientific whatever result low-wing Amptique see herein flew its checkout flightwhich lasted about 25 sec before motors plastic reduction gear assembly gave upand quick turn land low altitude made very ner vous because what looked like shallow dihe dral everything worked out OK Tom changed Astro 4046 gear boxthe Ive recommendingand plane its sec ond checkout flight few days later Report The plane flies bit great looks looks beautiful Nice work Tom Hey people photos Amp tique derivatives Two neat ideas show up same photo Dave 38 Model Aviation Radio Cono Electrics Bob Kopski 25 st End Dr Lansdale PA 19446 bound happen Meres Bob Humseys Electric ducted-tan plane modilled Kyosflo Cosmos kit powered Astro 15 cobalt Photo Below L shows Keith Shaw releasing hi-start-assisted launch pure hand-launch didnt give enough initial speed Ily 88 KRC Electric Fly Other photo shows modified fan blades cut 6 3 shortened duct made 2 layers thin ply 1/8-in ply ring formers Stators hold rolled-ply motor tube hurt ot Indiana PA let snap mis pooto unoer hatch new geared Astro 25-powered sport job What may clear pix motor attached Look ma no clamps motor glued Well its really glued Dave used clear silicone adhesive adhere motor ply wood plate latter held bearers screws whole idea behind twofold quietness soft mount Dave demonstrated mounting method significantly lowered motor really gear noise typifies geared Electrics What noisy Electric same time mounting technique tends Futabas new Electric Professor Kopski says its excellent flier just doesnt want come down Motor 540-size geared special prop Recommended battery 6cell although used 7 Best check availability replacement props/parts though dampen some always present vibration Dave vexy proud ideaas well should thats Didja notice greatlooking airacoops photo Neat huh Doncha just wonder make ones just like em Wonder no Dave tells sleek scoops nothing plastic table ware spoons course theyve trimmed down shown Next time go toss party picnic waste away make sure think twice Nice work Dave Now whats nonsense about noisy Elec trics Well youve probably heard sound geared Electric Its noticeably noisy direct drives Ive heard some pretty loud directs too latter gen erally small-propped high-rpm ones sorta whine Anyway vote consistently noisy Electrics gear drives noisy Would believe just 2 dB sound level quieter certain wet four-strokers Now thats downright threatening embarrassing thanks George Poos Ft Washington PA sound-level-meter info Daves idea may have happened just time us quiet guys re tain lowest power noise titie So much lighter side months col umn Now want get little technical direct ing attention recent issue Model Builder magazine November 88 issue Electric columnist Mitch Poling includes some considerable discussion simple mathematical relationships describing operation Elec tric motors turn5 Out both Mitch columnist benefactors input reader Ed Westbrook Chelmsford MA Ed obvi ously has strong technical background applied abilities some info appeared col umn July August 88 issues Continued page 149 SUCKER-KIT manually controlled vacuum bag system makes lay up process combination foam & skins trouble free fast first time SUCKER-KIT ...$5995 VHS Show & Tell Video$3995 Add $400 shipping & handling MI residents add 4O/ sales tax Send $100 SASE product list samples real wood veneer skins Product List Includes Gapless Arrow Shaft Hinges Carbon Tow Mylar Sheet High-Tech items Dealer Inquires Welcome SEND CHECK OR MONEY ORDER TO Box 866 Lapeer Ml 48446 313 664-3330 B&P Associates Gives Total Flight Line FREEDOM battery needs call write B&P Associates PO Box 22054 Waco TX 76702-2054 817662-5587 new electric starter battery pack cuts cord has always tied starter power panel Discover freedom being able start plane wherever added safety less wire get caught prop charge hefty 4 Amp/hour pack will take through weekend flying power enough spare dont stop have Ni-Cads virtually size imaginable cut experimenter free design whatever takes make yours best setup field February 1989 39 Tom Williamsons unnamed low-wing ver sion Leisure Amptique flies well Kopski would feel better tad dihedral Leisure LT-50 motor turns As tro gearbox uses seven BOO-mAh Ni-Cd cells Jomar SC-S speed control Two excellent new ideas turn up Dave Burts new sport design Geared 25 cobalt held plywood plate silicone rubber adhesive Plate screwed mount plane really quietens noise gear drivel Neat airscoops fabricated plastic picnic spoons NO MORE KICKBACKS THROWN PROPS popular best selling odd-on ignition system world convert engine spark ignition breakerless capacitive discharge ignition System can installed engines 60 up both 2 8 4 stroke both single & twin cylinders 4strokers run absolutely beautiful ignition 10 30% power 4utroke engine No kickbick throwing props Absolutely no predetonatioi deetl 4stroke engines Much lower priced fuel & no rusty hearings commercl fuel availeble Red-Mis Very low 9001000 rEp reliable idle easy hand starts yma can control ignition timing will stop pro-detonation engine will run mudi cooler develop power Now available conylefely shielded spork plug lied 90 plug cover Chosen T&G Mfg n Originals its outstanding reliability Send $1 00 price list newsletter ordering Box 1732 RIVOIONr WY 82501 307 857-6897 CH Electronics Inc TOLED THIRTY-FIFTH ANNUAL RADIO CONTROL EXPOSITION TOLEDO SPORTS ARENA ONE MAIN STREET TOLEDO OHIO ADVANCED TICKETS may ordered sending selfaddressed stamped business size 4Vax9 envelope TICKETS 38235 Castle Romulus Ml 48174 orders above 5 tickets must include extra postage US orders must include 25 centsper order handling charge foreign orders must include 50 cents per order handling charge need send addressed envelope will provide necessary postageExpress Mail Orders Will Accepted Include check money order US funds made payable Weak Signals R/C Club Ticket prices $400 per day adults $1 00 per dayfor children 12 under Please specify number Deadline ticket orders March 31 1989 sales final non-refundable TICKETSAREALSOAVAILABLEAT THE DOOR Exposition information available contacting Wayne Yeager co-director ticket address phone 313 941-6661 Bring latest completely finished models display enter competition exciting awards R/C radios will awarded first second third place winners following classes NON-MILITARY SPORT SCALE PLANE AMA Rules MILITARY SPORT SCALE PLANE AMA Rules PRECISION SCALE PLANE AMA Rules PATTERN PLANE SPORT MONO-PLANE non-scale models SPORT BI-PLANE non-scale models OLD TIMER FREE FLIGHT R/C ASSIST R/C SAILPLANE non-scale models No Engines HELICOPTER R/C CAR COMPETITION BOAT MILITARY SCALE BOAT PLEASURE POWER BOAT WORKING VESSEL-UNARMED models entered competition will judged Best Finish Best MonoKote Directors Award Best Show Come join us enjoy yourselves unquestionably worlds greatest radio control model show will have traditional Swap Shop Saturday Night Auction Open public three great days APRIL 7 8 9 1989 FRIDAY9am to6pm SATURDAY9amto6pm SUNDAY9 am 430 pm presented Weak Signals R/C Club Toledo Ohio crystals explained last month Airtronics Fu taba arent making interchangeable crystals avail able products Now know rest story what think should done about channels Dont tell write AMA dis trict VP can tell George sent HAPPY NEW YEAR Schuemann WinglCarr Continued page 37 fore reducing wings drag essentially way reduce overall drag best accomplished using fully sheeted wing modified Atrix model shown photos rib/spar built-up structure wing could have made sheeted foam No matter what material inside goal make glass-smooth surface still strong enough withstand hard launches keeping goal airfoil should chosen will yield good compromise between thermaling speed requirements Several Eppler Selig airfoils clearly top choices No matter use reduction drag inherent Schuemann planform will increase wings performance Nearly high-speed powered aircraft use wings tapered root tip Sailplanes other hand generally use constant chord partway tip increase strength Schuemann wing used Discus modified Atrix con stunt chord about half span out tip leading edge swept back intervals about 40% 20% 10% modified Atrix wing diagram indi cates exact proportions used tip latest Discus design employs mild up turn trailing edge similar old Aquila model Sailplane tip chord small however doubt upsweep really has much effect center pres sure airfoil blurred since moves aft progressively toward tip retards noticeable step some airfoils like Eppler 205 exhibit effect rather forgiving ship less touchy elevator same 205 airfoil double-tapered wing very nice windy weather light lift may flying hard edge envelope As sweptwing aircraft center-of-gravity CU needs further aft would straight wing modified Atrix will unflyable center-of-gravity 25% root chord becomes very civ ilized CU back 33% 35% Utilizing planform also has addi tional advantage Sailplane straight wing ballasting becomes necessary windy conditions make model able penetrate Herk Stokelys Soaring col umn2 states really need crease airspeed about half wind speed get decent penetration prob lem ballast remains airplane during entire flight model using clean low-drag Schue mann wing will have higher average unbal lasted speed still working light lift landing slowly planform can fly unballasted others loading up add weight search far downwind gale winds still make back landing circle As full-size Discus will have no trouble picking out Sailplane gaggle will probably highest flying several times faster oth ers working lift no else can reach References 1 Spackman Elliot Schuemann Wing Planform RIG Soaring Digest July 1988 2 Herk Stokely Flying Models magazine September 1988 Note ATRIX plans Model Aviation magazine December 1986 issue RC Electrics/Kopski Continued page 39 issues t offered some motor/prop/power/rpm data cobalt 05s Continued page 153 February 1989 149 RC Electrics/Kopski Continued page 149 iSs UGH despicable meaning less motor descriptions again Small world Nowwhats about deeply interested Elec tric stuff works beyond just finding out what mo tor use strongly encourage dig up magazines mentioned above see what good ies await discovery effect references describe some detail fi4lly characterize motors some simple measurementsor someone elses dataso can easily choose motor/battery/prop/power/rpm formation next Electric project insight afforded can scientifically enjoy wondrous Electric model power worlda world key element model doms future Sometime future will go matter column cannot access ref erences given above meantime please try dig up info referenced Beyond sug gest find following additional references 1 About Electric Sport Scale Keith Shaw Model Builder July 1987 2 About ElectricsPart Eight columnist Model Aviation April 1984 might also comment Mr Westbrook has utilized July/August data Ive several letters favor able comment So look such data motors etc future always try react incoming mail Ive said before column often guided what readers write An Electric ARE ARF almost-ready-to-fly flies very well Professor foamy 05-power Theres darned incompre hensible designator again hate sizeand pretty opportunity check out fel low club member qulte impressed Professor uses geared Mabuchi 540 cansize motor turns unusual prop Whats un usual prop threads onto output gear drive shaft special item Im sure availability either spare props other spare plane parts factor careful consideration youre thinking buying because nonbalsa planes can diffi cult repair youre interested sort plane consider fair must include fact sample Professor flew equipped seven 1 2-Ah cells instead recommended six used Astro speed control cannot say well regular six-cell-powered example would perform Anyway plenty go handied extremely well As equipped flights honest eight-tonine-minute range routine large flatbottomed wing easily handied 48-oz all-up load intended delve some technical ex perience particular plane lost notes What wanted describe flight particular wherein specifically wanted test Rule Thumb described Model Aviation reference given previously April 1984 article gave guideline amount power needed just cruise Electrics goes like Motor Power Input Cruise Watts l Weight lb x Wing Loading oz/sq ft Knowing models weight wing area 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order amount charge put battery should allow predict flight time under cruise conditionsie just maintaining level fight conditions relatively easy task Electric speed control Now data Well can tell pre dicted time came out within few seconds actual timeessentially dead-on Now know some would interested facts figures come across Ill include info future column perhaps can re peat test now another example Last issue made reference resurrected Exciter 40-size aerobatic photo see October 85 issue MA semisymmetrical-airfoiled NACA 2412 low-winger powered cobalt 40 18 12-Ab cells All-up weight 89 oz wing planform 10 x 60 600 sq basic info get Calculated Motor Power Input Cruise Watts 6 x 891600/144 556 lb x 2136 oz/sq ft about 119 watts question now long can described battery supply 119 watts course depends much charge battery ie amp-minutes pumped charged up set charge current constant 44 amps charged 15 mm Thats total 66 ampere-minutes Dur ing discharge under cruise conditions current drain relatively low fact current will approximately watts/voltage about 119/12 x 18 5 amps relatively low current average cell voltage during dis charge will close classic 12-volt value above can now calculate availNow fliers over world have neat inexpensive functional way protect R/C transmitters dirt dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus GeorgIa 31904 404/323-2787 9am-Spm EST able watt-minutes battery can deliver Typi cally Ni-Cd will deliver about 95% charge pumped Taking account could expect about 12 x 18 x 66 x 95 1354 watt-minutes calculated required power level 119 watts sustain cruise might therefore expect about 1354/119 114 minutes flight So what actual flight time attained Would believe 12 mm 10 sec Folks thats shabby Im convinced rule thumb pretty good nearly perfect Professor example described pretty good case variance plus side As addenda very next flight Ex citer wide open flew field perimeter more-or-less constant altitude full power time 4 mm 25 sec So what normal flight time Ex citer normal flight consists taxi/takeoff rolls inside loops square insides outside loops stall turns snaps touch-and-goes Cuban eights etc tallied up log 30 typical flights represented total time 1872 minutes average ffight time 6 mm 15 sec Folks thats lot good flyin Whats secret word speed control use power needed maneuver under way no back off throttle Im moving get position open er up needed Think power management youre using speed control plane could benefit suggest give try As Ive written previously speed control adds just dimension fun Electric Electric fun enough An observation year has much like other year During past month inFebruary 1989 153 7KANS-COVER New Rocket Uses B C andO Engines5. Capability No Else Offers MRCs recent introduction 25 Moonbiaster inter mediate kit brings yet another technological advance MRCs Computer Aided Designs CAD built carry B4-2 06-3 engines However Moonblaster also commercially sold rocket kit includes easy-touse adapter also allows use powerful Dengines Bulitto take blast Moonblaster features large die-cut balsa fins blowmolded nose cone superb space capsule detailing Self stick decals 18chute Send free catalog See full line advanced MRC rockets hobby dealer cant help call us directly MRCG Model Rectifier Corporation 2500 Woodbridge Ave Edison NJ 08817 201 985-7800 coming mail has low think reason twofold First time between sues ie between Nats November issue no columns December issue normal col umns Also major parts country its fall pre-winter So outa-sight outa mind effect seeing column month combined season speculate lowers reader interest past weeksince December issue hit streetsthe mail back love Reflecting season issue will no doubt hands just about holiday time timely opportunity wish happy safe memorable holiday Andfor coming yearplease have noth ing happy safe quiet Electric landings Thank everyone giving opportu nity afforded column share fun Please forward comment question SASE please want reply author address given very top column RC AerobaticsNan Putte Continued page 41 elementary school librarian last item Henry Ham 251 Calle Canon de Faber Green Valley AZ 85614 wrote need help can test data Clark Y airfoil Reynolds numbers greater 87000 ob tamed has found data Reynolds num ber source 10-in chord Reyn olds number 87000 corresponds 12 mph Data 300000 would better can remember some old NACA reports Twenties Thirties covered wind tunnel tests Clark Y cant remember Reynolds number source anymore anyone can help Henry please write him Editors note sent copy Ron s column comments new Carl Goldberg Models kits manufacturer company could aware good not-so-good things said about mew models provide opportunity comment Noted flier Dave Patrick responded behalf com pany following being substance views Vector model has flown extensively K&B Sportster 45 OS 3SFP both using muffler pressure pressurize fitel tank recommended instruction booklet out fidel feed problem Dave recommended moving servo end steering pushrod hale closer servo shaft servo output arm/disc steering found too sensitive rather replace kits nose wheel steering arm longer unit Eagle 2 Dave expressed surprise kind balsa sample kit far off desired grade believes Carl Goldberg Models has quality controls among best indus try Concerning power plant feels strongly sport 40 engine racing engine too much airplane especially take offs made grass surface RMcM RC Scale/Wischers Continued page 43 few pencil lines will suffice Anyone thinking about flying all-metal Ford Trimotor Brace wires Streamlined wires flight surfac es Scale models have simulated vari ous meansor sometimes entirely eliminated Some modelers have gone great lengths make wires true miniature renditions actual shape rolled wires full-sized aircraft quite complete machine shop con junction expert machinists know-how becomes necessity anyone taking route best have seen made Merritt Zim merman pair hardened rollers having semielliptical shape peripheries equipped handcrank squeeze wire round stock streamlined shape Its tricky process expert because wire stretches being rolled its initial length must somewhat less fin ished product past have described own process using three parallel music wire lengths sol dered together filed sanded streamlined shape look great suffi ciently stiff prevent sagging small tension spring used end latest method manufacture called attention John Bishop visited bike shop found stainless steel bicycle spokes Racing cyclists use reduce drag rap idly revolving wheel come limited range lengths problem being sizes closely grouped around 12 fit stan dard racing wheels small variations length due fact some wheels laced spoke crossing three four other spokes also accommodate variations hub diameters full length spoke isnt flattened streamlined shape useful small aircraft brace wires tail surfaces advantages bike spoke end threaded 2-56a very common size Most Scale modelers have nuts threading taps #11 BIadesE~ 1i 40 Pad $485 Dehvered 100 Pad $895 Berkeley Trading CoCAEMO PO Box 26 Berkeley Springs WV 254112J Send 55on nor complete line 154 Model Aviation WORmS orocest SCALE E,oro seRVICE 800 000 RACKS PLANS 3 VIEWS PHOTO-PACKS PLANS ENLARGING 5ASE Enlarging Wt Jin Pepinon Catalog *OOSCALE PLANS ad PHOTO SEH VICE 3209 Madoon Geennbno NC 27403 psoe i1519l2925239 No cnIlocrl sioo BIIE5UDP EL IlL RIDOE iaIog MACHINERY TOOL 8 P0 Box 536-V omoog icane wv 25526 off Er 304-562-3538 complete selecnion lathes mills nools Aviation Modeler
Edition: Model Aviation - 1989/02
Page Numbers: 38, 39, 149, 153, 154
TODAY shortest day year Its last chance evening flying tonight clocks go back hour hereafterfor what seems like foreverflying confined weekends cause simply gets too dark too early Well thats entirely true us night-flyin folks know may sound like its some thing can easily donebut Its actu ally very easy least planes fairly docile unsurprising easiest-to-fly safest night fliers Glider configuration Old-Timers honest trainers Just some thing ponder future Last month promised neat photo sequence first ducted-fan Electric Ive seen three subject photos included herein modeler Bob Rumsey regular attendee KRC Electric fly model old Kyosho design called Cosmos originally designed RK2O ducted fan driven wet power intended jet trainer has duct sit ting top V-type tail Bob lightened up considerably omitting landing gear wing tip stabilizers etc de spite heavy Electric installation about lb lighter original intent All-up weight about 54 oz 60-in wing pro viding about 3 sq ft area Power Astro 15 cobalt 14 800-mAh cells fan experimental Hobby Lobby item originally designed 60-size wet power plant Bob cut blades down 4/2-in diame ter oniy using three original six Blade pitch adjustable currently set about 21-amp draw battery power al location handled Jomar SC-4 speed control does fly YES first launch hand proved inadequate force attain necessary initial flying speed second high-start assist courtesy Keith Shaw did fly up away remember flight live just watched videotape short ago courtesy Lynton Younger Willoughby OH complete video camera As Ive said times meet brings em out Nice work Bob Yet another Ainptique derivative shown month modeler Tom Williamson Collegeville PA Tom decided add per sonal touch fine kit turning fuselage upside down sorta Actually Tom bit scientific whatever result low-wing Amptique see herein flew its checkout flightwhich lasted about 25 sec before motors plastic reduction gear assembly gave upand quick turn land low altitude made very ner vous because what looked like shallow dihe dral everything worked out OK Tom changed Astro 4046 gear boxthe Ive recommendingand plane its sec ond checkout flight few days later Report The plane flies bit great looks looks beautiful Nice work Tom Hey people photos Amp tique derivatives Two neat ideas show up same photo Dave 38 Model Aviation Radio Cono Electrics Bob Kopski 25 st End Dr Lansdale PA 19446 bound happen Meres Bob Humseys Electric ducted-tan plane modilled Kyosflo Cosmos kit powered Astro 15 cobalt Photo Below L shows Keith Shaw releasing hi-start-assisted launch pure hand-launch didnt give enough initial speed Ily 88 KRC Electric Fly Other photo shows modified fan blades cut 6 3 shortened duct made 2 layers thin ply 1/8-in ply ring formers Stators hold rolled-ply motor tube hurt ot Indiana PA let snap mis pooto unoer hatch new geared Astro 25-powered sport job What may clear pix motor attached Look ma no clamps motor glued Well its really glued Dave used clear silicone adhesive adhere motor ply wood plate latter held bearers screws whole idea behind twofold quietness soft mount Dave demonstrated mounting method significantly lowered motor really gear noise typifies geared Electrics What noisy Electric same time mounting technique tends Futabas new Electric Professor Kopski says its excellent flier just doesnt want come down Motor 540-size geared special prop Recommended battery 6cell although used 7 Best check availability replacement props/parts though dampen some always present vibration Dave vexy proud ideaas well should thats Didja notice greatlooking airacoops photo Neat huh Doncha just wonder make ones just like em Wonder no Dave tells sleek scoops nothing plastic table ware spoons course theyve trimmed down shown Next time go toss party picnic waste away make sure think twice Nice work Dave Now whats nonsense about noisy Elec trics Well youve probably heard sound geared Electric Its noticeably noisy direct drives Ive heard some pretty loud directs too latter gen erally small-propped high-rpm ones sorta whine Anyway vote consistently noisy Electrics gear drives noisy Would believe just 2 dB sound level quieter certain wet four-strokers Now thats downright threatening embarrassing thanks George Poos Ft Washington PA sound-level-meter info Daves idea may have happened just time us quiet guys re tain lowest power noise titie So much lighter side months col umn Now want get little technical direct ing attention recent issue Model Builder magazine November 88 issue Electric columnist Mitch Poling includes some considerable discussion simple mathematical relationships describing operation Elec tric motors turn5 Out both Mitch columnist benefactors input reader Ed Westbrook Chelmsford MA Ed obvi ously has strong technical background applied abilities some info appeared col umn July August 88 issues Continued page 149 SUCKER-KIT manually controlled vacuum bag system makes lay up process combination foam & skins trouble free fast first time SUCKER-KIT ...$5995 VHS Show & Tell Video$3995 Add $400 shipping & handling MI residents add 4O/ sales tax Send $100 SASE product list samples real wood veneer skins Product List Includes Gapless Arrow Shaft Hinges Carbon Tow Mylar Sheet High-Tech items Dealer Inquires Welcome SEND CHECK OR MONEY ORDER TO Box 866 Lapeer Ml 48446 313 664-3330 B&P Associates Gives Total Flight Line FREEDOM battery needs call write B&P Associates PO Box 22054 Waco TX 76702-2054 817662-5587 new electric starter battery pack cuts cord has always tied starter power panel Discover freedom being able start plane wherever added safety less wire get caught prop charge hefty 4 Amp/hour pack will take through weekend flying power enough spare dont stop have Ni-Cads virtually size imaginable cut experimenter free design whatever takes make yours best setup field February 1989 39 Tom Williamsons unnamed low-wing ver sion Leisure Amptique flies well Kopski would feel better tad dihedral Leisure LT-50 motor turns As tro gearbox uses seven BOO-mAh Ni-Cd cells Jomar SC-S speed control Two excellent new ideas turn up Dave Burts new sport design Geared 25 cobalt held plywood plate silicone rubber adhesive Plate screwed mount plane really quietens noise gear drivel Neat airscoops fabricated plastic picnic spoons NO MORE KICKBACKS THROWN PROPS popular best selling odd-on ignition system world convert engine spark ignition breakerless capacitive discharge ignition System can installed engines 60 up both 2 8 4 stroke both single & twin cylinders 4strokers run absolutely beautiful ignition 10 30% power 4utroke engine No kickbick throwing props Absolutely no predetonatioi deetl 4stroke engines Much lower priced fuel & no rusty hearings commercl fuel availeble Red-Mis Very low 9001000 rEp reliable idle easy hand starts yma can control ignition timing will stop pro-detonation engine will run mudi cooler develop power Now available conylefely shielded spork plug lied 90 plug cover Chosen T&G Mfg n Originals its outstanding reliability Send $1 00 price list newsletter ordering Box 1732 RIVOIONr WY 82501 307 857-6897 CH Electronics Inc TOLED THIRTY-FIFTH ANNUAL RADIO CONTROL EXPOSITION TOLEDO SPORTS ARENA ONE MAIN STREET TOLEDO OHIO ADVANCED TICKETS may ordered sending selfaddressed stamped business size 4Vax9 envelope TICKETS 38235 Castle Romulus Ml 48174 orders above 5 tickets must include extra postage US orders must include 25 centsper order handling charge foreign orders must include 50 cents per order handling charge need send addressed envelope will provide necessary postageExpress Mail Orders Will Accepted Include check money order US funds made payable Weak Signals R/C Club Ticket prices $400 per day adults $1 00 per dayfor children 12 under Please specify number Deadline ticket orders March 31 1989 sales final non-refundable TICKETSAREALSOAVAILABLEAT THE DOOR Exposition information available contacting Wayne Yeager co-director ticket address phone 313 941-6661 Bring latest completely finished models display enter competition exciting awards R/C radios will awarded first second third place winners following classes NON-MILITARY SPORT SCALE PLANE AMA Rules MILITARY SPORT SCALE PLANE AMA Rules PRECISION SCALE PLANE AMA Rules PATTERN PLANE SPORT MONO-PLANE non-scale models SPORT BI-PLANE non-scale models OLD TIMER FREE FLIGHT R/C ASSIST R/C SAILPLANE non-scale models No Engines HELICOPTER R/C CAR COMPETITION BOAT MILITARY SCALE BOAT PLEASURE POWER BOAT WORKING VESSEL-UNARMED models entered competition will judged Best Finish Best MonoKote Directors Award Best Show Come join us enjoy yourselves unquestionably worlds greatest radio control model show will have traditional Swap Shop Saturday Night Auction Open public three great days APRIL 7 8 9 1989 FRIDAY9am to6pm SATURDAY9amto6pm SUNDAY9 am 430 pm presented Weak Signals R/C Club Toledo Ohio crystals explained last month Airtronics Fu taba arent making interchangeable crystals avail able products Now know rest story what think should done about channels Dont tell write AMA dis trict VP can tell George sent HAPPY NEW YEAR Schuemann WinglCarr Continued page 37 fore reducing wings drag essentially way reduce overall drag best accomplished using fully sheeted wing modified Atrix model shown photos rib/spar built-up structure wing could have made sheeted foam No matter what material inside goal make glass-smooth surface still strong enough withstand hard launches keeping goal airfoil should chosen will yield good compromise between thermaling speed requirements Several Eppler Selig airfoils clearly top choices No matter use reduction drag inherent Schuemann planform will increase wings performance Nearly high-speed powered aircraft use wings tapered root tip Sailplanes other hand generally use constant chord partway tip increase strength Schuemann wing used Discus modified Atrix con stunt chord about half span out tip leading edge swept back intervals about 40% 20% 10% modified Atrix wing diagram indi cates exact proportions used tip latest Discus design employs mild up turn trailing edge similar old Aquila model Sailplane tip chord small however doubt upsweep really has much effect center pres sure airfoil blurred since moves aft progressively toward tip retards noticeable step some airfoils like Eppler 205 exhibit effect rather forgiving ship less touchy elevator same 205 airfoil double-tapered wing very nice windy weather light lift may flying hard edge envelope As sweptwing aircraft center-of-gravity CU needs further aft would straight wing modified Atrix will unflyable center-of-gravity 25% root chord becomes very civ ilized CU back 33% 35% Utilizing planform also has addi tional advantage Sailplane straight wing ballasting becomes necessary windy conditions make model able penetrate Herk Stokelys Soaring col umn2 states really need crease airspeed about half wind speed get decent penetration prob lem ballast remains airplane during entire flight model using clean low-drag Schue mann wing will have higher average unbal lasted speed still working light lift landing slowly planform can fly unballasted others loading up add weight search far downwind gale winds still make back landing circle As full-size Discus will have no trouble picking out Sailplane gaggle will probably highest flying several times faster oth ers working lift no else can reach References 1 Spackman Elliot Schuemann Wing Planform RIG Soaring Digest July 1988 2 Herk Stokely Flying Models magazine September 1988 Note ATRIX plans Model Aviation magazine December 1986 issue RC Electrics/Kopski Continued page 39 issues t offered some motor/prop/power/rpm data cobalt 05s Continued page 153 February 1989 149 RC Electrics/Kopski Continued page 149 iSs UGH despicable meaning less motor descriptions again Small world Nowwhats about deeply interested Elec tric stuff works beyond just finding out what mo tor use strongly encourage dig up magazines mentioned above see what good ies await discovery effect references describe some detail fi4lly characterize motors some simple measurementsor someone elses dataso can easily choose motor/battery/prop/power/rpm formation next Electric project insight afforded can scientifically enjoy wondrous Electric model power worlda world key element model doms future Sometime future will go matter column cannot access ref erences given above meantime please try dig up info referenced Beyond sug gest find following additional references 1 About Electric Sport Scale Keith Shaw Model Builder July 1987 2 About ElectricsPart Eight columnist Model Aviation April 1984 might also comment Mr Westbrook has utilized July/August data Ive several letters favor able comment So look such data motors etc future always try react incoming mail Ive said before column often guided what readers write An Electric ARE ARF almost-ready-to-fly flies very well Professor foamy 05-power Theres darned incompre hensible designator again hate sizeand pretty opportunity check out fel low club member qulte impressed Professor uses geared Mabuchi 540 cansize motor turns unusual prop Whats un usual prop threads onto output gear drive shaft special item Im sure availability either spare props other spare plane parts factor careful consideration youre thinking buying because nonbalsa planes can diffi cult repair youre interested sort plane consider fair must include fact sample Professor flew equipped seven 1 2-Ah cells instead recommended six used Astro speed control cannot say well regular six-cell-powered example would perform Anyway plenty go handied extremely well As equipped flights honest eight-tonine-minute range routine large flatbottomed wing easily handied 48-oz all-up load intended delve some technical ex perience particular plane lost notes What wanted describe flight particular wherein specifically wanted test Rule Thumb described Model Aviation reference given previously April 1984 article gave guideline amount power needed just cruise Electrics goes like Motor Power Input Cruise Watts l Weight lb x Wing Loading oz/sq ft Knowing models weight wing area 3 dozen $400 ea 4 dozen $375 ea 5 dozen $360 ea 6 dozen $355 ea Add $400 shipping per order Please send good black white art reproduction Please specify quantity Trans-Cover colors ink color ordering Limit ink color per order amount charge put battery should allow predict flight time under cruise conditionsie just maintaining level fight conditions relatively easy task Electric speed control Now data Well can tell pre dicted time came out within few seconds actual timeessentially dead-on Now know some would interested facts figures come across Ill include info future column perhaps can re peat test now another example Last issue made reference resurrected Exciter 40-size aerobatic photo see October 85 issue MA semisymmetrical-airfoiled NACA 2412 low-winger powered cobalt 40 18 12-Ab cells All-up weight 89 oz wing planform 10 x 60 600 sq basic info get Calculated Motor Power Input Cruise Watts 6 x 891600/144 556 lb x 2136 oz/sq ft about 119 watts question now long can described battery supply 119 watts course depends much charge battery ie amp-minutes pumped charged up set charge current constant 44 amps charged 15 mm Thats total 66 ampere-minutes Dur ing discharge under cruise conditions current drain relatively low fact current will approximately watts/voltage about 119/12 x 18 5 amps relatively low current average cell voltage during dis charge will close classic 12-volt value above can now calculate availNow fliers over world have neat inexpensive functional way protect R/C transmitters dirt dust rain Custom printed club logo Constructed durable canvas lifelong Velcro closure Available red blue green yellow orange black Colors can mixed size fits Send check money order KD GRAPHICS 3315 13th Avenue Columbus GeorgIa 31904 404/323-2787 9am-Spm EST able watt-minutes battery can deliver Typi cally Ni-Cd will deliver about 95% charge pumped Taking account could expect about 12 x 18 x 66 x 95 1354 watt-minutes calculated required power level 119 watts sustain cruise might therefore expect about 1354/119 114 minutes flight So what actual flight time attained Would believe 12 mm 10 sec Folks thats shabby Im convinced rule thumb pretty good nearly perfect Professor example described pretty good case variance plus side As addenda very next flight Ex citer wide open flew field perimeter more-or-less constant altitude full power time 4 mm 25 sec So what normal flight time Ex citer normal flight consists taxi/takeoff rolls inside loops square insides outside loops stall turns snaps touch-and-goes Cuban eights etc tallied up log 30 typical flights represented total time 1872 minutes average ffight time 6 mm 15 sec Folks thats lot good flyin Whats secret word speed control use power needed maneuver under way no back off throttle Im moving get position open er up needed Think power management youre using speed control plane could benefit suggest give try As Ive written previously speed control adds just dimension fun Electric Electric fun enough An observation year has much like other year During past month inFebruary 1989 153 7KANS-COVER New Rocket Uses B C andO Engines5. Capability No Else Offers MRCs recent introduction 25 Moonbiaster inter mediate kit brings yet another technological advance MRCs Computer Aided Designs CAD built carry B4-2 06-3 engines However Moonblaster also commercially sold rocket kit includes easy-touse adapter also allows use powerful Dengines Bulitto take blast Moonblaster features large die-cut balsa fins blowmolded nose cone superb space capsule detailing Self stick decals 18chute Send free catalog See full line advanced MRC rockets hobby dealer cant help call us directly MRCG Model Rectifier Corporation 2500 Woodbridge Ave Edison NJ 08817 201 985-7800 coming mail has low think reason twofold First time between sues ie between Nats November issue no columns December issue normal col umns Also major parts country its fall pre-winter So outa-sight outa mind effect seeing column month combined season speculate lowers reader interest past weeksince December issue hit streetsthe mail back love Reflecting season issue will no doubt hands just about holiday time timely opportunity wish happy safe memorable holiday Andfor coming yearplease have noth ing happy safe quiet Electric landings Thank everyone giving opportu nity afforded column share fun Please forward comment question SASE please want reply author address given very top column RC AerobaticsNan Putte Continued page 41 elementary school librarian last item Henry Ham 251 Calle Canon de Faber Green Valley AZ 85614 wrote need help can test data Clark Y airfoil Reynolds numbers greater 87000 ob tamed has found data Reynolds num ber source 10-in chord Reyn olds number 87000 corresponds 12 mph Data 300000 would better can remember some old NACA reports Twenties Thirties covered wind tunnel tests Clark Y cant remember Reynolds number source anymore anyone can help Henry please write him Editors note sent copy Ron s column comments new Carl Goldberg Models kits manufacturer company could aware good not-so-good things said about mew models provide opportunity comment Noted flier Dave Patrick responded behalf com pany following being substance views Vector model has flown extensively K&B Sportster 45 OS 3SFP both using muffler pressure pressurize fitel tank recommended instruction booklet out fidel feed problem Dave recommended moving servo end steering pushrod hale closer servo shaft servo output arm/disc steering found too sensitive rather replace kits nose wheel steering arm longer unit Eagle 2 Dave expressed surprise kind balsa sample kit far off desired grade believes Carl Goldberg Models has quality controls among best indus try Concerning power plant feels strongly sport 40 engine racing engine too much airplane especially take offs made grass surface RMcM RC Scale/Wischers Continued page 43 few pencil lines will suffice Anyone thinking about flying all-metal Ford Trimotor Brace wires Streamlined wires flight surfac es Scale models have simulated vari ous meansor sometimes entirely eliminated Some modelers have gone great lengths make wires true miniature renditions actual shape rolled wires full-sized aircraft quite complete machine shop con junction expert machinists know-how becomes necessity anyone taking route best have seen made Merritt Zim merman pair hardened rollers having semielliptical shape peripheries equipped handcrank squeeze wire round stock streamlined shape Its tricky process expert because wire stretches being rolled its initial length must somewhat less fin ished product past have described own process using three parallel music wire lengths sol dered together filed sanded streamlined shape look great suffi ciently stiff prevent sagging small tension spring used end latest method manufacture called attention John Bishop visited bike shop found stainless steel bicycle spokes Racing cyclists use reduce drag rap idly revolving wheel come limited range lengths problem being sizes closely grouped around 12 fit stan dard racing wheels small variations length due fact some wheels laced spoke crossing three four other spokes also accommodate variations hub diameters full length spoke isnt flattened streamlined shape useful small aircraft brace wires tail surfaces advantages bike spoke end threaded 2-56a very common size Most Scale modelers have nuts threading taps #11 BIadesE~ 1i 40 Pad $485 Dehvered 100 Pad $895 Berkeley Trading CoCAEMO PO Box 26 Berkeley Springs WV 254112J Send 55on nor complete line 154 Model Aviation WORmS orocest SCALE E,oro seRVICE 800 000 RACKS PLANS 3 VIEWS PHOTO-PACKS PLANS ENLARGING 5ASE Enlarging Wt Jin Pepinon Catalog *OOSCALE PLANS ad PHOTO SEH VICE 3209 Madoon Geennbno NC 27403 psoe i1519l2925239 No cnIlocrl sioo BIIE5UDP EL IlL RIDOE iaIog MACHINERY TOOL 8 P0 Box 536-V omoog icane wv 25526 off Er 304-562-3538 complete selecnion lathes mills nools Aviation Modeler