fl4jj IJL As often has past RC once again comes aid high-tech researcher instance its op erate test equipment inside NASA vacuum chamber Maybe someday well see descendant setup operat ing vacuum outer space EDon Edberg THIS IS THE STORY used skills knowledge gained years modeling carry out some engineering research efficient way have flying RC Sailpianes over 13 years among chal lenging unique uses RC Ive run across story began about two years ago graduate student Stanford University northern California beginning plan dissertation approached advisor some advice suggested investigate subject damping What damping may ask quality materials dissipates ener gy vibration instance ring bell ringing eventually stops bell rung vacuum another hr way expressing laws thermody namics say simplified terms cant get something nothing other words because no material perfect will dissipate energy eventually stop vibrating suggested damping topic because very important behavior space structures particularly large flimsy ones Imagine yourself astronaut new space station space shuttle docks bit hard sends shock waves through station damping very lnw tRtifln will vlhr2tp far haiir ,nt1 Left inside chamber priorto vacuum being drawn forklift Futaba J-seriea transmitter ueed operate Notice Ni-Cds previous picture have repiaced seaied gel cells known operate safely under vacuum Right RC spring-powered resettable launcher Abiiity retrieve test specimen reset launcher outside chamber saved hours 42 Model Aviation 7Shown during its development testing outside vacuum chamber RC forkiift returns iauncher carrying test specimen 6-in rule shows relative sizes energy dissipated Clearly would hard carry out astronomical observa tions station shaking time example unwanted vibrations could cause trouble space others So important accurately know damping ma terials used construct space station Thus started looking material damp ing Please patient RC really involved story Like other modelers enjoy tin kering mechanical gadgets decided try measure damping experimen tally make measurements would directly applicable prob lems large space structures Most aware conditions spacezero gravity free-fall vacuum conditions set out repeat own testing As might imagine easiest thing simulate vacuum space got permission testing large vacuum chamber NASA Ames Research Center chamber has floor 10 feet side eight-foot-high ceiling can evacuated 995% vacuum good enough purposes took care vacuum part problem still figure out way simulate zero-gravity part project began read articles technical journals describing research done others Soon ran across some work done Massachusetts Institute Technology similar what interested simulated zero gravity launching specimen freefall technique looked very promising except used wires attached specimen get data seemed having specimen dragging around wires free-fall would affect vibrations trying measure tried think way could differently finally decided design miniature telemetry system transmit data back receiving station learned bit about elec tronics making printed-circuit boards found miniature transmitter designed medical implantation modified would transmit vibrational informa tion designed printed circuit board hold components including 20 mAh Ni-Cd batteries setup could operate continuously eight hours total mass 30 grams bit ounce next problem figure out some way launch specimen freefall would simulate zero-gravity en vironment decided build springpowered launcher bounce specimens free-fall case after some chanical designs didnt work properly decided model apparatus after used MIT groupbut some simplifications launcher shown picture has two vertical rods springs around moving part launcher placed above springs test specimen top springs compressed moving part launcher released order launch model free-fall specimen placed top launcher continues upward free-fall almost ceiling finally hits floor size vacuum chamber allows free-fall time about 14 seconds enough get reasonable data big question should run experiment could get work done least amount time two choices first release vacuum open up vacuum chamber reset launcher hand put specimen top launcher close chamber pull vacuum repeat test seoond build some mechan ism could remotely reset launcher some sort robot could pick up specimen put back top launcherso would need open close vacuum chamber door process opening closing door including bleeding off repulling vacuum took 20 minutes wanted tests hour just two three background RC can guess chose second possibility carry out experiment necessary build remote resetting mechanism launcher shown pictures mechanical system consists moving platform holding very powerful electromagnet platform may raised lowered RC reset launcher reset platform raised electromagnet just touching bottom moving plate electromagnet turned platform lowered mechanically same time compressing large springs either side springs compressed proper amount platform stopped electromagnet turned off moving part launcher free accelerated upward springs launcher hits stops top vertical rods specimen placed top launcher continues upward free-fall come up some way getting specimen back top launching mechanism discussed prob em good friend Brian Chan also happens outstanding modeler some very creative ideas After brain storming came up idea using miniature RC forklift means resetting experiment Brian needed project design class San Francisco State agreed would design forklift experiment Thus killed two projects forklift forklift has four functions forward reverse steering lift up down kneeling first two functions obvious second two could use bit explanation lift up/down function used lift specimen up top launcher after has hit ground kneel function allows lift mechanism tilt forward its arms can fit underneath specimen ground function required because floor vacuum chamber covered foam rubber specimen telemetry system wouldnt damaged hit Continued page 136 Left Vacuum chamberatthe Ames Research Center Only point entry chamberforthe radio signalewasthe Piexiglaswindow radios performed tiawiessiy Right Test specimen used damping experiments Wireiessteiemetry provided clean accurate data August1986 43 IfyoushouldthinkofslipflOtethatB3 what youd see wing RC pilot OK know better say matter relative wind acting upon dihedraled wings banked turn inside wing has greater angle attack outside stabilizes fun Does centrifugal force play part location CGthat high low pendulum effect What does presence centrifugal force banked turn know nothing Dont ask offer C old-fashioned turn-and-bank indicator instrnment tilted would leftbanked turn slip skid yaw equalized pilot coordination ball cen tered skid greater ball would move toward right side slip greater ball sinks toward left side plane itself can center ball what modelers call spirally stable piloting input required neutrally-stable moreacrobatic craft machine man together still center ball ball will center design has some deficiency difficult fly unflyable Whimsy flat-winged Stik close hands-off FF flat-winged Lacey Fike will fly OK Air three-dimensional often think terms two dimensionslike diagram Drop wing aileron pull upelevator model whips around know wing loadings go sky high high some times small heavy models youll snap out control plane pushing agalnst alr toward outside turn its angle attack affected holding upelevator wing perhaps nearer stall large part due centrifugal force free-to-pivot pendulum hung beneath belly would point wonders about Frank Zaics book Circu lar Airflow available AMA Supply & Service Section wondered about airflow phenomenawith turn-and-banked aircraftmany years ago Ive models would fly themselves around 360add bit nose weight becomes 720 vice-versa until cant hold 360 Such models seemingly can fine-tuned go neutrally stable banked circles yet flying hands-off neither recover ing nor degrading continuous-banked turns Argue leave out dont know nuttinunless name Tschirgi Planes wonderful things Perhaps ought wonder Bill Winter 4432 Altura Ct. Faitfax VA 22030 Radio Technique/Myers Continued page 41 redundant RF link Roland Spicer fascinating person talk pursued dream setting RC cross-country record great care intelligence describes event enthusiasm would credit much younger man can see Roland airplane description flight RC Video Magazine Volume 3 plane scale model Wallace Beerys Bellanca dedicated Rolands lifetime friend Allison Buck can seen hanglng ceiling AMA museum AMA Headquarters building Reston VA Ask Hurst Bowers tell about case havent noticed better times interference- reliability-wise rnshing down us George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 RC Aid/Edberg Continued page 43 forklift required four RC channels launcher required two platform up/down launcher release decided use single transmitter con trol both gadgets same time wouldnt need juggle transmitters running experiment decided use trusty Futaba J Series system needed least six channels available Because two receivers would inside vacuum chamber made 1-in-thick solid steel walls felt using J Series quite reasonable transmitter shown behind forklift shots way radio signals get through receivers inside chamber through small Plexiglas window concerned two receivers same fre quency might interfere other both RC systems performed flawlessly through testing As far know first time model RC system has operated vacuum two receivers sub jected share electrical noise motors powered both forklift resetting mechanism launcher noise did affect operation receivers made big racket FM receiver used gather data telemetry system later found out several companies manufacture brushless DC motors supposed operate vacuum out generating electrical noise Next time Im using vacuum Ill give try Both forklift launcher pow ered sealed lead-acid D cells having 4 Ah capacity huge batteries known safe operate vacuum recharged after days testing constant-voltage charger case forklift extra weight lead-acid cells helped provide extra traction driving around foam rubber However often quite enough made snow tires pushing staples facing outward through tires cured traction problem launcher forklift arrangement worked extremely well After bit practice became proficient enough two oould have specimen back top launcher within 2 minutes may seem long time until consider specimen bounces ran domly foam-rubber-covered floor takes 90 seconds just recycle launcher case much less time 20 minutes needed recycle vacuum chamber wont go details results testing because really terest people field space craft dynamics will say results good enough Stanford award 136 Model Aviation Eke. Quality r S 937 x 156 x 175 18 oz 46 oz torque Years development have produced finest state-ofthe art receivers ever made Flight tests over country haveThe workhorse Ace servos Perfect Patternships Quarter Scale Boats Cars proven receiver will fly others fail Solid glitch-freeapplication high power required performance air plane attitude frequencies/channelsLIIIIIJ 14G20AAtlas Servo Kit$2395 Available Z7 50 53 72 75mHzAC 14G2OACAtlas Servo assembled$3146 12G70 Silver Seven Receiver Kit$3895 Available dealer order direct add $200 Ace RIC 116W 19th St Box SuB Higginsville MO 64037 816 584-721 S aV0 iOld Timer fOttS66Si5A3 CbauiW0From sparK 1etS poliltS Taflt5 tjtooe IgnitiOn Engine Parts Only Over 600 items Send $200 current catalog PhD am now planning proposal orbit scale model large space struc ture inside Space Shuttle test using RC operating equipment ows. someday might see astronaut holding RC transmitter Space Shuffle RC Scale/Wischers Continued page 47 tion will recall said earlier AC location does depend relative cidence wing tail Since true might conclude incidence angles have nothing stability abso lutely correct contrary what modelers lieve What relative incidence between wing stabilizer actually does set AQA airplane will trim elevators neutral Since models fly various AQAs small AQAs fast parts flight large AQAs aerobatics takeoff landing relative incidence setting up model er depending flight condition wants model trimmed set wrong relative incidence its no big deal Thats have adjustable control linkages trim control transmitter mistake some people make setting incidences shown plans moving CG until model flies desired AQA speed elevators neutral very bright idea may move CG far aft goes aft AC making airplane unstable Rather fall trap set level longitudinal stability proper place ment CG play hori zontal tail incidence elevator trim until airplane trims desired AQA speed Youll like airplanes handling qualities bet ter crash less often save ballast weight thanks James Ruley foregoing treatise longitudinal stability Scale model ers build kits magazine drawings will have little concern difference inci dence angles between wing stabilizer would have properly set up designer model intentionally set up zero-zero incidence angles provide Patternmodel-type performance will probably have neutral stability will need flown like Pattern ship no relaxation during flight neutral stability model needs continuous control input will climb vertically until runs out energy straight down until meets earth no tendency recover level flight its own stability model will have its CO AC same vertical line experienced fli ers prefer such models especially have background Pattern flying have flown neutrally-stable trainers have hearing Pattern fliers zero-zero angle setup model no longer favored now preference about /2 0 1 0 incidence wing relative stabilizer equal amount downthrust engine mount intend ed provide straight flight transmitter control inputs during vertical maneuvers gravity forces directed toward tail modeler likely concerned about incidence angles person prefers design scratch-build fac tory drawings three-view drawings means measurements taken directly subject aircraft modeler die-hard Scale purist insists upon copying fullsize prototype down last detail including incidence angles wing stabilizer numerous examples aircraft drastic angular differences much 60 Taylorcraft Staggerwing Beechcraft come mind result such setup down-load stabilizer high-wing cabin type also down-load tail due downwash off wing trailing edge case AC affected since total lift sum lift produced wing horizontal tail difference between two forces wing now must lift airplane weight plus stabilizer down-force AC now moves far forward positive longitudi nal stability CG must also moved far forward ahead AC Balancing such model favored 25% 30% wing chord doesnt assure stability particularly takeoff its first flight flier isnt prepared initial steep climb results stall snap roll crash disappoint ed modeler gathers pieces trash bag recommend reducing angular differ ence about 20 kits Spitfire full-size illustrated has 20 incidence wing 00 stabilizer 20 washout wing tip flier knows what expect large angular difference between wing stabilizer incidence built solidly fuselage structure cant easily changed model will have flown elevators drooping drastically experience know diffi cult hold Up elevator throughout first-flight 1748 AD GOES tWIN OUR BACK PA GE AD VERIISEAENT WORLDS 7 CH FM EXPERT len say own 7 diarmel 4 channel Expert FM tiei converson Systems say have 4 5 eliplanes want put receiver mdi eliplane era say tosterice yolfte diarmel 40 youl send franesltter will special line receivers VanenIlter -1 10 morethe nwnber exta receivers mares no ifleresce Retail pace therecelverls$8995Therewil odlwgelortrdngandwe1 pay outhozid freight have another franmeltrer diwnist 46 wait another mo&ie another receiver channel 4 thate eisa poselto hat cue have buy another tanmidlter mo&ie TranmnltW Mo6ie refi plc $4950 EXPERT 7 CHANNEL FEA TURES 1 Dual conversion FM erotIc 2 nicads chaiger 3 Reversing channels 4 Lodvng connectors 5 Dual rate aileron elevator 6 Mixing aileron & rudder elevator & Itapa 7 Servos use Mdstishi #15660 chp 8 ServOs use indirect drive 9 Excellent operation AM envimnment 10 Receiver uses ubra narrow band mufti-pole ceramic filters SERVO 52885 TJL sar LOClirda orweercrw JUSTARRIVEDI COMO 29 RIC Como 29 ie Ike eil engtoea tie cisro toe Sclsruerle pcrbd engtoe orankeliaft aipported doutoc bail beings 11w cano 29155 real powertdant planes like Woild Ennea Widoerd ARF comno 25 allwood Flince ARF rIta Retail plc Ccmo 29 $8495 JUSTARRIVED ZENOAHG-62 Zertoir 042 Isa 378 cikdc todrmagsetolrWonengtoethat toni power standpoInt drordd sqlivalent just tout eie thIs displacement tie madret 0-62 designed light weIrL lAilSer mont toduded lIds angita Retail pike tog pertonner $25985 EXPERT ACCESSORIES Shoen below ue acoessceles Expert FM ltoa cormectors selt-locidrig tyse prevent dtocorsiecton S-25 servo gaas wi avitla U2tfl 5weoTay fl fl I1i 2W1 Servo Ora Ii wAodg ousdor ss Rsa 0 ElEl iTS 24 5wvoEo-oi wAedJng onsiector $450 & ssou ReliC EiipsstNdx Step S59S Retodi NEW CHINA CLIPPER FROM ~TEH Sport version canopy town luIt consfruof Thgqran 5I 3-4 drarmela S- 40 sagne Otidrle 503 SMSS Reti WORLD ENGINES 0960 Rossash Ave cincinnati Ohio 45236 Phone 513 793-50OU Telex 214557 FAX 513 793-7337 August 1986 137 MABYCHI MOTOR $229 15 - 9 Volts HARRY B HIGLEY S SONS INC P 0 BOX 532 GLENWOOD ILL 60425
Edition: Model Aviation - 1986/08
Page Numbers: 42, 43, 136, 137
fl4jj IJL As often has past RC once again comes aid high-tech researcher instance its op erate test equipment inside NASA vacuum chamber Maybe someday well see descendant setup operat ing vacuum outer space EDon Edberg THIS IS THE STORY used skills knowledge gained years modeling carry out some engineering research efficient way have flying RC Sailpianes over 13 years among chal lenging unique uses RC Ive run across story began about two years ago graduate student Stanford University northern California beginning plan dissertation approached advisor some advice suggested investigate subject damping What damping may ask quality materials dissipates ener gy vibration instance ring bell ringing eventually stops bell rung vacuum another hr way expressing laws thermody namics say simplified terms cant get something nothing other words because no material perfect will dissipate energy eventually stop vibrating suggested damping topic because very important behavior space structures particularly large flimsy ones Imagine yourself astronaut new space station space shuttle docks bit hard sends shock waves through station damping very lnw tRtifln will vlhr2tp far haiir ,nt1 Left inside chamber priorto vacuum being drawn forklift Futaba J-seriea transmitter ueed operate Notice Ni-Cds previous picture have repiaced seaied gel cells known operate safely under vacuum Right RC spring-powered resettable launcher Abiiity retrieve test specimen reset launcher outside chamber saved hours 42 Model Aviation 7Shown during its development testing outside vacuum chamber RC forkiift returns iauncher carrying test specimen 6-in rule shows relative sizes energy dissipated Clearly would hard carry out astronomical observa tions station shaking time example unwanted vibrations could cause trouble space others So important accurately know damping ma terials used construct space station Thus started looking material damp ing Please patient RC really involved story Like other modelers enjoy tin kering mechanical gadgets decided try measure damping experimen tally make measurements would directly applicable prob lems large space structures Most aware conditions spacezero gravity free-fall vacuum conditions set out repeat own testing As might imagine easiest thing simulate vacuum space got permission testing large vacuum chamber NASA Ames Research Center chamber has floor 10 feet side eight-foot-high ceiling can evacuated 995% vacuum good enough purposes took care vacuum part problem still figure out way simulate zero-gravity part project began read articles technical journals describing research done others Soon ran across some work done Massachusetts Institute Technology similar what interested simulated zero gravity launching specimen freefall technique looked very promising except used wires attached specimen get data seemed having specimen dragging around wires free-fall would affect vibrations trying measure tried think way could differently finally decided design miniature telemetry system transmit data back receiving station learned bit about elec tronics making printed-circuit boards found miniature transmitter designed medical implantation modified would transmit vibrational informa tion designed printed circuit board hold components including 20 mAh Ni-Cd batteries setup could operate continuously eight hours total mass 30 grams bit ounce next problem figure out some way launch specimen freefall would simulate zero-gravity en vironment decided build springpowered launcher bounce specimens free-fall case after some chanical designs didnt work properly decided model apparatus after used MIT groupbut some simplifications launcher shown picture has two vertical rods springs around moving part launcher placed above springs test specimen top springs compressed moving part launcher released order launch model free-fall specimen placed top launcher continues upward free-fall almost ceiling finally hits floor size vacuum chamber allows free-fall time about 14 seconds enough get reasonable data big question should run experiment could get work done least amount time two choices first release vacuum open up vacuum chamber reset launcher hand put specimen top launcher close chamber pull vacuum repeat test seoond build some mechan ism could remotely reset launcher some sort robot could pick up specimen put back top launcherso would need open close vacuum chamber door process opening closing door including bleeding off repulling vacuum took 20 minutes wanted tests hour just two three background RC can guess chose second possibility carry out experiment necessary build remote resetting mechanism launcher shown pictures mechanical system consists moving platform holding very powerful electromagnet platform may raised lowered RC reset launcher reset platform raised electromagnet just touching bottom moving plate electromagnet turned platform lowered mechanically same time compressing large springs either side springs compressed proper amount platform stopped electromagnet turned off moving part launcher free accelerated upward springs launcher hits stops top vertical rods specimen placed top launcher continues upward free-fall come up some way getting specimen back top launching mechanism discussed prob em good friend Brian Chan also happens outstanding modeler some very creative ideas After brain storming came up idea using miniature RC forklift means resetting experiment Brian needed project design class San Francisco State agreed would design forklift experiment Thus killed two projects forklift forklift has four functions forward reverse steering lift up down kneeling first two functions obvious second two could use bit explanation lift up/down function used lift specimen up top launcher after has hit ground kneel function allows lift mechanism tilt forward its arms can fit underneath specimen ground function required because floor vacuum chamber covered foam rubber specimen telemetry system wouldnt damaged hit Continued page 136 Left Vacuum chamberatthe Ames Research Center Only point entry chamberforthe radio signalewasthe Piexiglaswindow radios performed tiawiessiy Right Test specimen used damping experiments Wireiessteiemetry provided clean accurate data August1986 43 IfyoushouldthinkofslipflOtethatB3 what youd see wing RC pilot OK know better say matter relative wind acting upon dihedraled wings banked turn inside wing has greater angle attack outside stabilizes fun Does centrifugal force play part location CGthat high low pendulum effect What does presence centrifugal force banked turn know nothing Dont ask offer C old-fashioned turn-and-bank indicator instrnment tilted would leftbanked turn slip skid yaw equalized pilot coordination ball cen tered skid greater ball would move toward right side slip greater ball sinks toward left side plane itself can center ball what modelers call spirally stable piloting input required neutrally-stable moreacrobatic craft machine man together still center ball ball will center design has some deficiency difficult fly unflyable Whimsy flat-winged Stik close hands-off FF flat-winged Lacey Fike will fly OK Air three-dimensional often think terms two dimensionslike diagram Drop wing aileron pull upelevator model whips around know wing loadings go sky high high some times small heavy models youll snap out control plane pushing agalnst alr toward outside turn its angle attack affected holding upelevator wing perhaps nearer stall large part due centrifugal force free-to-pivot pendulum hung beneath belly would point wonders about Frank Zaics book Circu lar Airflow available AMA Supply & Service Section wondered about airflow phenomenawith turn-and-banked aircraftmany years ago Ive models would fly themselves around 360add bit nose weight becomes 720 vice-versa until cant hold 360 Such models seemingly can fine-tuned go neutrally stable banked circles yet flying hands-off neither recover ing nor degrading continuous-banked turns Argue leave out dont know nuttinunless name Tschirgi Planes wonderful things Perhaps ought wonder Bill Winter 4432 Altura Ct. Faitfax VA 22030 Radio Technique/Myers Continued page 41 redundant RF link Roland Spicer fascinating person talk pursued dream setting RC cross-country record great care intelligence describes event enthusiasm would credit much younger man can see Roland airplane description flight RC Video Magazine Volume 3 plane scale model Wallace Beerys Bellanca dedicated Rolands lifetime friend Allison Buck can seen hanglng ceiling AMA museum AMA Headquarters building Reston VA Ask Hurst Bowers tell about case havent noticed better times interference- reliability-wise rnshing down us George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 RC Aid/Edberg Continued page 43 forklift required four RC channels launcher required two platform up/down launcher release decided use single transmitter con trol both gadgets same time wouldnt need juggle transmitters running experiment decided use trusty Futaba J Series system needed least six channels available Because two receivers would inside vacuum chamber made 1-in-thick solid steel walls felt using J Series quite reasonable transmitter shown behind forklift shots way radio signals get through receivers inside chamber through small Plexiglas window concerned two receivers same fre quency might interfere other both RC systems performed flawlessly through testing As far know first time model RC system has operated vacuum two receivers sub jected share electrical noise motors powered both forklift resetting mechanism launcher noise did affect operation receivers made big racket FM receiver used gather data telemetry system later found out several companies manufacture brushless DC motors supposed operate vacuum out generating electrical noise Next time Im using vacuum Ill give try Both forklift launcher pow ered sealed lead-acid D cells having 4 Ah capacity huge batteries known safe operate vacuum recharged after days testing constant-voltage charger case forklift extra weight lead-acid cells helped provide extra traction driving around foam rubber However often quite enough made snow tires pushing staples facing outward through tires cured traction problem launcher forklift arrangement worked extremely well After bit practice became proficient enough two oould have specimen back top launcher within 2 minutes may seem long time until consider specimen bounces ran domly foam-rubber-covered floor takes 90 seconds just recycle launcher case much less time 20 minutes needed recycle vacuum chamber wont go details results testing because really terest people field space craft dynamics will say results good enough Stanford award 136 Model Aviation Eke. Quality r S 937 x 156 x 175 18 oz 46 oz torque Years development have produced finest state-ofthe art receivers ever made Flight tests over country haveThe workhorse Ace servos Perfect Patternships Quarter Scale Boats Cars proven receiver will fly others fail Solid glitch-freeapplication high power required performance air plane attitude frequencies/channelsLIIIIIJ 14G20AAtlas Servo Kit$2395 Available Z7 50 53 72 75mHzAC 14G2OACAtlas Servo assembled$3146 12G70 Silver Seven Receiver Kit$3895 Available dealer order direct add $200 Ace RIC 116W 19th St Box SuB Higginsville MO 64037 816 584-721 S aV0 iOld Timer fOttS66Si5A3 CbauiW0From sparK 1etS poliltS Taflt5 tjtooe IgnitiOn Engine Parts Only Over 600 items Send $200 current catalog PhD am now planning proposal orbit scale model large space struc ture inside Space Shuttle test using RC operating equipment ows. someday might see astronaut holding RC transmitter Space Shuffle RC Scale/Wischers Continued page 47 tion will recall said earlier AC location does depend relative cidence wing tail Since true might conclude incidence angles have nothing stability abso lutely correct contrary what modelers lieve What relative incidence between wing stabilizer actually does set AQA airplane will trim elevators neutral Since models fly various AQAs small AQAs fast parts flight large AQAs aerobatics takeoff landing relative incidence setting up model er depending flight condition wants model trimmed set wrong relative incidence its no big deal Thats have adjustable control linkages trim control transmitter mistake some people make setting incidences shown plans moving CG until model flies desired AQA speed elevators neutral very bright idea may move CG far aft goes aft AC making airplane unstable Rather fall trap set level longitudinal stability proper place ment CG play hori zontal tail incidence elevator trim until airplane trims desired AQA speed Youll like airplanes handling qualities bet ter crash less often save ballast weight thanks James Ruley foregoing treatise longitudinal stability Scale model ers build kits magazine drawings will have little concern difference inci dence angles between wing stabilizer would have properly set up designer model intentionally set up zero-zero incidence angles provide Patternmodel-type performance will probably have neutral stability will need flown like Pattern ship no relaxation during flight neutral stability model needs continuous control input will climb vertically until runs out energy straight down until meets earth no tendency recover level flight its own stability model will have its CO AC same vertical line experienced fli ers prefer such models especially have background Pattern flying have flown neutrally-stable trainers have hearing Pattern fliers zero-zero angle setup model no longer favored now preference about /2 0 1 0 incidence wing relative stabilizer equal amount downthrust engine mount intend ed provide straight flight transmitter control inputs during vertical maneuvers gravity forces directed toward tail modeler likely concerned about incidence angles person prefers design scratch-build fac tory drawings three-view drawings means measurements taken directly subject aircraft modeler die-hard Scale purist insists upon copying fullsize prototype down last detail including incidence angles wing stabilizer numerous examples aircraft drastic angular differences much 60 Taylorcraft Staggerwing Beechcraft come mind result such setup down-load stabilizer high-wing cabin type also down-load tail due downwash off wing trailing edge case AC affected since total lift sum lift produced wing horizontal tail difference between two forces wing now must lift airplane weight plus stabilizer down-force AC now moves far forward positive longitudi nal stability CG must also moved far forward ahead AC Balancing such model favored 25% 30% wing chord doesnt assure stability particularly takeoff its first flight flier isnt prepared initial steep climb results stall snap roll crash disappoint ed modeler gathers pieces trash bag recommend reducing angular differ ence about 20 kits Spitfire full-size illustrated has 20 incidence wing 00 stabilizer 20 washout wing tip flier knows what expect large angular difference between wing stabilizer incidence built solidly fuselage structure cant easily changed model will have flown elevators drooping drastically experience know diffi cult hold Up elevator throughout first-flight 1748 AD GOES tWIN OUR BACK PA GE AD VERIISEAENT WORLDS 7 CH FM EXPERT len say own 7 diarmel 4 channel Expert FM tiei converson Systems say have 4 5 eliplanes want put receiver mdi eliplane era say tosterice yolfte diarmel 40 youl send franesltter will special line receivers VanenIlter -1 10 morethe nwnber exta receivers mares no ifleresce Retail pace therecelverls$8995Therewil odlwgelortrdngandwe1 pay outhozid freight have another franmeltrer diwnist 46 wait another mo&ie another receiver channel 4 thate eisa poselto hat cue have buy another tanmidlter mo&ie TranmnltW Mo6ie refi plc $4950 EXPERT 7 CHANNEL FEA TURES 1 Dual conversion FM erotIc 2 nicads chaiger 3 Reversing channels 4 Lodvng connectors 5 Dual rate aileron elevator 6 Mixing aileron & rudder elevator & Itapa 7 Servos use Mdstishi #15660 chp 8 ServOs use indirect drive 9 Excellent operation AM envimnment 10 Receiver uses ubra narrow band mufti-pole ceramic filters SERVO 52885 TJL sar LOClirda orweercrw JUSTARRIVEDI COMO 29 RIC Como 29 ie Ike eil engtoea tie cisro toe Sclsruerle pcrbd engtoe orankeliaft aipported doutoc bail beings 11w cano 29155 real powertdant planes like Woild Ennea Widoerd ARF comno 25 allwood Flince ARF rIta Retail plc Ccmo 29 $8495 JUSTARRIVED ZENOAHG-62 Zertoir 042 Isa 378 cikdc todrmagsetolrWonengtoethat toni power standpoInt drordd sqlivalent just tout eie thIs displacement tie madret 0-62 designed light weIrL lAilSer mont toduded lIds angita Retail pike tog pertonner $25985 EXPERT ACCESSORIES Shoen below ue acoessceles Expert FM ltoa cormectors selt-locidrig tyse prevent dtocorsiecton S-25 servo gaas wi avitla U2tfl 5weoTay fl fl I1i 2W1 Servo Ora Ii wAodg ousdor ss Rsa 0 ElEl iTS 24 5wvoEo-oi wAedJng onsiector $450 & ssou ReliC EiipsstNdx Step S59S Retodi NEW CHINA CLIPPER FROM ~TEH Sport version canopy town luIt consfruof Thgqran 5I 3-4 drarmela S- 40 sagne Otidrle 503 SMSS Reti WORLD ENGINES 0960 Rossash Ave cincinnati Ohio 45236 Phone 513 793-50OU Telex 214557 FAX 513 793-7337 August 1986 137 MABYCHI MOTOR $229 15 - 9 Volts HARRY B HIGLEY S SONS INC P 0 BOX 532 GLENWOOD ILL 60425
Edition: Model Aviation - 1986/08
Page Numbers: 42, 43, 136, 137
fl4jj IJL As often has past RC once again comes aid high-tech researcher instance its op erate test equipment inside NASA vacuum chamber Maybe someday well see descendant setup operat ing vacuum outer space EDon Edberg THIS IS THE STORY used skills knowledge gained years modeling carry out some engineering research efficient way have flying RC Sailpianes over 13 years among chal lenging unique uses RC Ive run across story began about two years ago graduate student Stanford University northern California beginning plan dissertation approached advisor some advice suggested investigate subject damping What damping may ask quality materials dissipates ener gy vibration instance ring bell ringing eventually stops bell rung vacuum another hr way expressing laws thermody namics say simplified terms cant get something nothing other words because no material perfect will dissipate energy eventually stop vibrating suggested damping topic because very important behavior space structures particularly large flimsy ones Imagine yourself astronaut new space station space shuttle docks bit hard sends shock waves through station damping very lnw tRtifln will vlhr2tp far haiir ,nt1 Left inside chamber priorto vacuum being drawn forklift Futaba J-seriea transmitter ueed operate Notice Ni-Cds previous picture have repiaced seaied gel cells known operate safely under vacuum Right RC spring-powered resettable launcher Abiiity retrieve test specimen reset launcher outside chamber saved hours 42 Model Aviation 7Shown during its development testing outside vacuum chamber RC forkiift returns iauncher carrying test specimen 6-in rule shows relative sizes energy dissipated Clearly would hard carry out astronomical observa tions station shaking time example unwanted vibrations could cause trouble space others So important accurately know damping ma terials used construct space station Thus started looking material damp ing Please patient RC really involved story Like other modelers enjoy tin kering mechanical gadgets decided try measure damping experimen tally make measurements would directly applicable prob lems large space structures Most aware conditions spacezero gravity free-fall vacuum conditions set out repeat own testing As might imagine easiest thing simulate vacuum space got permission testing large vacuum chamber NASA Ames Research Center chamber has floor 10 feet side eight-foot-high ceiling can evacuated 995% vacuum good enough purposes took care vacuum part problem still figure out way simulate zero-gravity part project began read articles technical journals describing research done others Soon ran across some work done Massachusetts Institute Technology similar what interested simulated zero gravity launching specimen freefall technique looked very promising except used wires attached specimen get data seemed having specimen dragging around wires free-fall would affect vibrations trying measure tried think way could differently finally decided design miniature telemetry system transmit data back receiving station learned bit about elec tronics making printed-circuit boards found miniature transmitter designed medical implantation modified would transmit vibrational informa tion designed printed circuit board hold components including 20 mAh Ni-Cd batteries setup could operate continuously eight hours total mass 30 grams bit ounce next problem figure out some way launch specimen freefall would simulate zero-gravity en vironment decided build springpowered launcher bounce specimens free-fall case after some chanical designs didnt work properly decided model apparatus after used MIT groupbut some simplifications launcher shown picture has two vertical rods springs around moving part launcher placed above springs test specimen top springs compressed moving part launcher released order launch model free-fall specimen placed top launcher continues upward free-fall almost ceiling finally hits floor size vacuum chamber allows free-fall time about 14 seconds enough get reasonable data big question should run experiment could get work done least amount time two choices first release vacuum open up vacuum chamber reset launcher hand put specimen top launcher close chamber pull vacuum repeat test seoond build some mechan ism could remotely reset launcher some sort robot could pick up specimen put back top launcherso would need open close vacuum chamber door process opening closing door including bleeding off repulling vacuum took 20 minutes wanted tests hour just two three background RC can guess chose second possibility carry out experiment necessary build remote resetting mechanism launcher shown pictures mechanical system consists moving platform holding very powerful electromagnet platform may raised lowered RC reset launcher reset platform raised electromagnet just touching bottom moving plate electromagnet turned platform lowered mechanically same time compressing large springs either side springs compressed proper amount platform stopped electromagnet turned off moving part launcher free accelerated upward springs launcher hits stops top vertical rods specimen placed top launcher continues upward free-fall come up some way getting specimen back top launching mechanism discussed prob em good friend Brian Chan also happens outstanding modeler some very creative ideas After brain storming came up idea using miniature RC forklift means resetting experiment Brian needed project design class San Francisco State agreed would design forklift experiment Thus killed two projects forklift forklift has four functions forward reverse steering lift up down kneeling first two functions obvious second two could use bit explanation lift up/down function used lift specimen up top launcher after has hit ground kneel function allows lift mechanism tilt forward its arms can fit underneath specimen ground function required because floor vacuum chamber covered foam rubber specimen telemetry system wouldnt damaged hit Continued page 136 Left Vacuum chamberatthe Ames Research Center Only point entry chamberforthe radio signalewasthe Piexiglaswindow radios performed tiawiessiy Right Test specimen used damping experiments Wireiessteiemetry provided clean accurate data August1986 43 IfyoushouldthinkofslipflOtethatB3 what youd see wing RC pilot OK know better say matter relative wind acting upon dihedraled wings banked turn inside wing has greater angle attack outside stabilizes fun Does centrifugal force play part location CGthat high low pendulum effect What does presence centrifugal force banked turn know nothing Dont ask offer C old-fashioned turn-and-bank indicator instrnment tilted would leftbanked turn slip skid yaw equalized pilot coordination ball cen tered skid greater ball would move toward right side slip greater ball sinks toward left side plane itself can center ball what modelers call spirally stable piloting input required neutrally-stable moreacrobatic craft machine man together still center ball ball will center design has some deficiency difficult fly unflyable Whimsy flat-winged Stik close hands-off FF flat-winged Lacey Fike will fly OK Air three-dimensional often think terms two dimensionslike diagram Drop wing aileron pull upelevator model whips around know wing loadings go sky high high some times small heavy models youll snap out control plane pushing agalnst alr toward outside turn its angle attack affected holding upelevator wing perhaps nearer stall large part due centrifugal force free-to-pivot pendulum hung beneath belly would point wonders about Frank Zaics book Circu lar Airflow available AMA Supply & Service Section wondered about airflow phenomenawith turn-and-banked aircraftmany years ago Ive models would fly themselves around 360add bit nose weight becomes 720 vice-versa until cant hold 360 Such models seemingly can fine-tuned go neutrally stable banked circles yet flying hands-off neither recover ing nor degrading continuous-banked turns Argue leave out dont know nuttinunless name Tschirgi Planes wonderful things Perhaps ought wonder Bill Winter 4432 Altura Ct. Faitfax VA 22030 Radio Technique/Myers Continued page 41 redundant RF link Roland Spicer fascinating person talk pursued dream setting RC cross-country record great care intelligence describes event enthusiasm would credit much younger man can see Roland airplane description flight RC Video Magazine Volume 3 plane scale model Wallace Beerys Bellanca dedicated Rolands lifetime friend Allison Buck can seen hanglng ceiling AMA museum AMA Headquarters building Reston VA Ask Hurst Bowers tell about case havent noticed better times interference- reliability-wise rnshing down us George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 RC Aid/Edberg Continued page 43 forklift required four RC channels launcher required two platform up/down launcher release decided use single transmitter con trol both gadgets same time wouldnt need juggle transmitters running experiment decided use trusty Futaba J Series system needed least six channels available Because two receivers would inside vacuum chamber made 1-in-thick solid steel walls felt using J Series quite reasonable transmitter shown behind forklift shots way radio signals get through receivers inside chamber through small Plexiglas window concerned two receivers same fre quency might interfere other both RC systems performed flawlessly through testing As far know first time model RC system has operated vacuum two receivers sub jected share electrical noise motors powered both forklift resetting mechanism launcher noise did affect operation receivers made big racket FM receiver used gather data telemetry system later found out several companies manufacture brushless DC motors supposed operate vacuum out generating electrical noise Next time Im using vacuum Ill give try Both forklift launcher pow ered sealed lead-acid D cells having 4 Ah capacity huge batteries known safe operate vacuum recharged after days testing constant-voltage charger case forklift extra weight lead-acid cells helped provide extra traction driving around foam rubber However often quite enough made snow tires pushing staples facing outward through tires cured traction problem launcher forklift arrangement worked extremely well After bit practice became proficient enough two oould have specimen back top launcher within 2 minutes may seem long time until consider specimen bounces ran domly foam-rubber-covered floor takes 90 seconds just recycle launcher case much less time 20 minutes needed recycle vacuum chamber wont go details results testing because really terest people field space craft dynamics will say results good enough Stanford award 136 Model Aviation Eke. Quality r S 937 x 156 x 175 18 oz 46 oz torque Years development have produced finest state-ofthe art receivers ever made Flight tests over country haveThe workhorse Ace servos Perfect Patternships Quarter Scale Boats Cars proven receiver will fly others fail Solid glitch-freeapplication high power required performance air plane attitude frequencies/channelsLIIIIIJ 14G20AAtlas Servo Kit$2395 Available Z7 50 53 72 75mHzAC 14G2OACAtlas Servo assembled$3146 12G70 Silver Seven Receiver Kit$3895 Available dealer order direct add $200 Ace RIC 116W 19th St Box SuB Higginsville MO 64037 816 584-721 S aV0 iOld Timer fOttS66Si5A3 CbauiW0From sparK 1etS poliltS Taflt5 tjtooe IgnitiOn Engine Parts Only Over 600 items Send $200 current catalog PhD am now planning proposal orbit scale model large space struc ture inside Space Shuttle test using RC operating equipment ows. someday might see astronaut holding RC transmitter Space Shuffle RC Scale/Wischers Continued page 47 tion will recall said earlier AC location does depend relative cidence wing tail Since true might conclude incidence angles have nothing stability abso lutely correct contrary what modelers lieve What relative incidence between wing stabilizer actually does set AQA airplane will trim elevators neutral Since models fly various AQAs small AQAs fast parts flight large AQAs aerobatics takeoff landing relative incidence setting up model er depending flight condition wants model trimmed set wrong relative incidence its no big deal Thats have adjustable control linkages trim control transmitter mistake some people make setting incidences shown plans moving CG until model flies desired AQA speed elevators neutral very bright idea may move CG far aft goes aft AC making airplane unstable Rather fall trap set level longitudinal stability proper place ment CG play hori zontal tail incidence elevator trim until airplane trims desired AQA speed Youll like airplanes handling qualities bet ter crash less often save ballast weight thanks James Ruley foregoing treatise longitudinal stability Scale model ers build kits magazine drawings will have little concern difference inci dence angles between wing stabilizer would have properly set up designer model intentionally set up zero-zero incidence angles provide Patternmodel-type performance will probably have neutral stability will need flown like Pattern ship no relaxation during flight neutral stability model needs continuous control input will climb vertically until runs out energy straight down until meets earth no tendency recover level flight its own stability model will have its CO AC same vertical line experienced fli ers prefer such models especially have background Pattern flying have flown neutrally-stable trainers have hearing Pattern fliers zero-zero angle setup model no longer favored now preference about /2 0 1 0 incidence wing relative stabilizer equal amount downthrust engine mount intend ed provide straight flight transmitter control inputs during vertical maneuvers gravity forces directed toward tail modeler likely concerned about incidence angles person prefers design scratch-build fac tory drawings three-view drawings means measurements taken directly subject aircraft modeler die-hard Scale purist insists upon copying fullsize prototype down last detail including incidence angles wing stabilizer numerous examples aircraft drastic angular differences much 60 Taylorcraft Staggerwing Beechcraft come mind result such setup down-load stabilizer high-wing cabin type also down-load tail due downwash off wing trailing edge case AC affected since total lift sum lift produced wing horizontal tail difference between two forces wing now must lift airplane weight plus stabilizer down-force AC now moves far forward positive longitudi nal stability CG must also moved far forward ahead AC Balancing such model favored 25% 30% wing chord doesnt assure stability particularly takeoff its first flight flier isnt prepared initial steep climb results stall snap roll crash disappoint ed modeler gathers pieces trash bag recommend reducing angular differ ence about 20 kits Spitfire full-size illustrated has 20 incidence wing 00 stabilizer 20 washout wing tip flier knows what expect large angular difference between wing stabilizer incidence built solidly fuselage structure cant easily changed model will have flown elevators drooping drastically experience know diffi cult hold Up elevator throughout first-flight 1748 AD GOES tWIN OUR BACK PA GE AD VERIISEAENT WORLDS 7 CH FM EXPERT len say own 7 diarmel 4 channel Expert FM tiei converson Systems say have 4 5 eliplanes want put receiver mdi eliplane era say tosterice yolfte diarmel 40 youl send franesltter will special line receivers VanenIlter -1 10 morethe nwnber exta receivers mares no ifleresce Retail pace therecelverls$8995Therewil odlwgelortrdngandwe1 pay outhozid freight have another franmeltrer diwnist 46 wait another mo&ie another receiver channel 4 thate eisa poselto hat cue have buy another tanmidlter mo&ie TranmnltW Mo6ie refi plc $4950 EXPERT 7 CHANNEL FEA TURES 1 Dual conversion FM erotIc 2 nicads chaiger 3 Reversing channels 4 Lodvng connectors 5 Dual rate aileron elevator 6 Mixing aileron & rudder elevator & Itapa 7 Servos use Mdstishi #15660 chp 8 ServOs use indirect drive 9 Excellent operation AM envimnment 10 Receiver uses ubra narrow band mufti-pole ceramic filters SERVO 52885 TJL sar LOClirda orweercrw JUSTARRIVEDI COMO 29 RIC Como 29 ie Ike eil engtoea tie cisro toe Sclsruerle pcrbd engtoe orankeliaft aipported doutoc bail beings 11w cano 29155 real powertdant planes like Woild Ennea Widoerd ARF comno 25 allwood Flince ARF rIta Retail plc Ccmo 29 $8495 JUSTARRIVED ZENOAHG-62 Zertoir 042 Isa 378 cikdc todrmagsetolrWonengtoethat toni power standpoInt drordd sqlivalent just tout eie thIs displacement tie madret 0-62 designed light weIrL lAilSer mont toduded lIds angita Retail pike tog pertonner $25985 EXPERT ACCESSORIES Shoen below ue acoessceles Expert FM ltoa cormectors selt-locidrig tyse prevent dtocorsiecton S-25 servo gaas wi avitla U2tfl 5weoTay fl fl I1i 2W1 Servo Ora Ii wAodg ousdor ss Rsa 0 ElEl iTS 24 5wvoEo-oi wAedJng onsiector $450 & ssou ReliC EiipsstNdx Step S59S Retodi NEW CHINA CLIPPER FROM ~TEH Sport version canopy town luIt consfruof Thgqran 5I 3-4 drarmela S- 40 sagne Otidrle 503 SMSS Reti WORLD ENGINES 0960 Rossash Ave cincinnati Ohio 45236 Phone 513 793-50OU Telex 214557 FAX 513 793-7337 August 1986 137 MABYCHI MOTOR $229 15 - 9 Volts HARRY B HIGLEY S SONS INC P 0 BOX 532 GLENWOOD ILL 60425
Edition: Model Aviation - 1986/08
Page Numbers: 42, 43, 136, 137
fl4jj IJL As often has past RC once again comes aid high-tech researcher instance its op erate test equipment inside NASA vacuum chamber Maybe someday well see descendant setup operat ing vacuum outer space EDon Edberg THIS IS THE STORY used skills knowledge gained years modeling carry out some engineering research efficient way have flying RC Sailpianes over 13 years among chal lenging unique uses RC Ive run across story began about two years ago graduate student Stanford University northern California beginning plan dissertation approached advisor some advice suggested investigate subject damping What damping may ask quality materials dissipates ener gy vibration instance ring bell ringing eventually stops bell rung vacuum another hr way expressing laws thermody namics say simplified terms cant get something nothing other words because no material perfect will dissipate energy eventually stop vibrating suggested damping topic because very important behavior space structures particularly large flimsy ones Imagine yourself astronaut new space station space shuttle docks bit hard sends shock waves through station damping very lnw tRtifln will vlhr2tp far haiir ,nt1 Left inside chamber priorto vacuum being drawn forklift Futaba J-seriea transmitter ueed operate Notice Ni-Cds previous picture have repiaced seaied gel cells known operate safely under vacuum Right RC spring-powered resettable launcher Abiiity retrieve test specimen reset launcher outside chamber saved hours 42 Model Aviation 7Shown during its development testing outside vacuum chamber RC forkiift returns iauncher carrying test specimen 6-in rule shows relative sizes energy dissipated Clearly would hard carry out astronomical observa tions station shaking time example unwanted vibrations could cause trouble space others So important accurately know damping ma terials used construct space station Thus started looking material damp ing Please patient RC really involved story Like other modelers enjoy tin kering mechanical gadgets decided try measure damping experimen tally make measurements would directly applicable prob lems large space structures Most aware conditions spacezero gravity free-fall vacuum conditions set out repeat own testing As might imagine easiest thing simulate vacuum space got permission testing large vacuum chamber NASA Ames Research Center chamber has floor 10 feet side eight-foot-high ceiling can evacuated 995% vacuum good enough purposes took care vacuum part problem still figure out way simulate zero-gravity part project began read articles technical journals describing research done others Soon ran across some work done Massachusetts Institute Technology similar what interested simulated zero gravity launching specimen freefall technique looked very promising except used wires attached specimen get data seemed having specimen dragging around wires free-fall would affect vibrations trying measure tried think way could differently finally decided design miniature telemetry system transmit data back receiving station learned bit about elec tronics making printed-circuit boards found miniature transmitter designed medical implantation modified would transmit vibrational informa tion designed printed circuit board hold components including 20 mAh Ni-Cd batteries setup could operate continuously eight hours total mass 30 grams bit ounce next problem figure out some way launch specimen freefall would simulate zero-gravity en vironment decided build springpowered launcher bounce specimens free-fall case after some chanical designs didnt work properly decided model apparatus after used MIT groupbut some simplifications launcher shown picture has two vertical rods springs around moving part launcher placed above springs test specimen top springs compressed moving part launcher released order launch model free-fall specimen placed top launcher continues upward free-fall almost ceiling finally hits floor size vacuum chamber allows free-fall time about 14 seconds enough get reasonable data big question should run experiment could get work done least amount time two choices first release vacuum open up vacuum chamber reset launcher hand put specimen top launcher close chamber pull vacuum repeat test seoond build some mechan ism could remotely reset launcher some sort robot could pick up specimen put back top launcherso would need open close vacuum chamber door process opening closing door including bleeding off repulling vacuum took 20 minutes wanted tests hour just two three background RC can guess chose second possibility carry out experiment necessary build remote resetting mechanism launcher shown pictures mechanical system consists moving platform holding very powerful electromagnet platform may raised lowered RC reset launcher reset platform raised electromagnet just touching bottom moving plate electromagnet turned platform lowered mechanically same time compressing large springs either side springs compressed proper amount platform stopped electromagnet turned off moving part launcher free accelerated upward springs launcher hits stops top vertical rods specimen placed top launcher continues upward free-fall come up some way getting specimen back top launching mechanism discussed prob em good friend Brian Chan also happens outstanding modeler some very creative ideas After brain storming came up idea using miniature RC forklift means resetting experiment Brian needed project design class San Francisco State agreed would design forklift experiment Thus killed two projects forklift forklift has four functions forward reverse steering lift up down kneeling first two functions obvious second two could use bit explanation lift up/down function used lift specimen up top launcher after has hit ground kneel function allows lift mechanism tilt forward its arms can fit underneath specimen ground function required because floor vacuum chamber covered foam rubber specimen telemetry system wouldnt damaged hit Continued page 136 Left Vacuum chamberatthe Ames Research Center Only point entry chamberforthe radio signalewasthe Piexiglaswindow radios performed tiawiessiy Right Test specimen used damping experiments Wireiessteiemetry provided clean accurate data August1986 43 IfyoushouldthinkofslipflOtethatB3 what youd see wing RC pilot OK know better say matter relative wind acting upon dihedraled wings banked turn inside wing has greater angle attack outside stabilizes fun Does centrifugal force play part location CGthat high low pendulum effect What does presence centrifugal force banked turn know nothing Dont ask offer C old-fashioned turn-and-bank indicator instrnment tilted would leftbanked turn slip skid yaw equalized pilot coordination ball cen tered skid greater ball would move toward right side slip greater ball sinks toward left side plane itself can center ball what modelers call spirally stable piloting input required neutrally-stable moreacrobatic craft machine man together still center ball ball will center design has some deficiency difficult fly unflyable Whimsy flat-winged Stik close hands-off FF flat-winged Lacey Fike will fly OK Air three-dimensional often think terms two dimensionslike diagram Drop wing aileron pull upelevator model whips around know wing loadings go sky high high some times small heavy models youll snap out control plane pushing agalnst alr toward outside turn its angle attack affected holding upelevator wing perhaps nearer stall large part due centrifugal force free-to-pivot pendulum hung beneath belly would point wonders about Frank Zaics book Circu lar Airflow available AMA Supply & Service Section wondered about airflow phenomenawith turn-and-banked aircraftmany years ago Ive models would fly themselves around 360add bit nose weight becomes 720 vice-versa until cant hold 360 Such models seemingly can fine-tuned go neutrally stable banked circles yet flying hands-off neither recover ing nor degrading continuous-banked turns Argue leave out dont know nuttinunless name Tschirgi Planes wonderful things Perhaps ought wonder Bill Winter 4432 Altura Ct. Faitfax VA 22030 Radio Technique/Myers Continued page 41 redundant RF link Roland Spicer fascinating person talk pursued dream setting RC cross-country record great care intelligence describes event enthusiasm would credit much younger man can see Roland airplane description flight RC Video Magazine Volume 3 plane scale model Wallace Beerys Bellanca dedicated Rolands lifetime friend Allison Buck can seen hanglng ceiling AMA museum AMA Headquarters building Reston VA Ask Hurst Bowers tell about case havent noticed better times interference- reliability-wise rnshing down us George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 RC Aid/Edberg Continued page 43 forklift required four RC channels launcher required two platform up/down launcher release decided use single transmitter con trol both gadgets same time wouldnt need juggle transmitters running experiment decided use trusty Futaba J Series system needed least six channels available Because two receivers would inside vacuum chamber made 1-in-thick solid steel walls felt using J Series quite reasonable transmitter shown behind forklift shots way radio signals get through receivers inside chamber through small Plexiglas window concerned two receivers same fre quency might interfere other both RC systems performed flawlessly through testing As far know first time model RC system has operated vacuum two receivers sub jected share electrical noise motors powered both forklift resetting mechanism launcher noise did affect operation receivers made big racket FM receiver used gather data telemetry system later found out several companies manufacture brushless DC motors supposed operate vacuum out generating electrical noise Next time Im using vacuum Ill give try Both forklift launcher pow ered sealed lead-acid D cells having 4 Ah capacity huge batteries known safe operate vacuum recharged after days testing constant-voltage charger case forklift extra weight lead-acid cells helped provide extra traction driving around foam rubber However often quite enough made snow tires pushing staples facing outward through tires cured traction problem launcher forklift arrangement worked extremely well After bit practice became proficient enough two oould have specimen back top launcher within 2 minutes may seem long time until consider specimen bounces ran domly foam-rubber-covered floor takes 90 seconds just recycle launcher case much less time 20 minutes needed recycle vacuum chamber wont go details results testing because really terest people field space craft dynamics will say results good enough Stanford award 136 Model Aviation Eke. Quality r S 937 x 156 x 175 18 oz 46 oz torque Years development have produced finest state-ofthe art receivers ever made Flight tests over country haveThe workhorse Ace servos Perfect Patternships Quarter Scale Boats Cars proven receiver will fly others fail Solid glitch-freeapplication high power required performance air plane attitude frequencies/channelsLIIIIIJ 14G20AAtlas Servo Kit$2395 Available Z7 50 53 72 75mHzAC 14G2OACAtlas Servo assembled$3146 12G70 Silver Seven Receiver Kit$3895 Available dealer order direct add $200 Ace RIC 116W 19th St Box SuB Higginsville MO 64037 816 584-721 S aV0 iOld Timer fOttS66Si5A3 CbauiW0From sparK 1etS poliltS Taflt5 tjtooe IgnitiOn Engine Parts Only Over 600 items Send $200 current catalog PhD am now planning proposal orbit scale model large space struc ture inside Space Shuttle test using RC operating equipment ows. someday might see astronaut holding RC transmitter Space Shuffle RC Scale/Wischers Continued page 47 tion will recall said earlier AC location does depend relative cidence wing tail Since true might conclude incidence angles have nothing stability abso lutely correct contrary what modelers lieve What relative incidence between wing stabilizer actually does set AQA airplane will trim elevators neutral Since models fly various AQAs small AQAs fast parts flight large AQAs aerobatics takeoff landing relative incidence setting up model er depending flight condition wants model trimmed set wrong relative incidence its no big deal Thats have adjustable control linkages trim control transmitter mistake some people make setting incidences shown plans moving CG until model flies desired AQA speed elevators neutral very bright idea may move CG far aft goes aft AC making airplane unstable Rather fall trap set level longitudinal stability proper place ment CG play hori zontal tail incidence elevator trim until airplane trims desired AQA speed Youll like airplanes handling qualities bet ter crash less often save ballast weight thanks James Ruley foregoing treatise longitudinal stability Scale model ers build kits magazine drawings will have little concern difference inci dence angles between wing stabilizer would have properly set up designer model intentionally set up zero-zero incidence angles provide Patternmodel-type performance will probably have neutral stability will need flown like Pattern ship no relaxation during flight neutral stability model needs continuous control input will climb vertically until runs out energy straight down until meets earth no tendency recover level flight its own stability model will have its CO AC same vertical line experienced fli ers prefer such models especially have background Pattern flying have flown neutrally-stable trainers have hearing Pattern fliers zero-zero angle setup model no longer favored now preference about /2 0 1 0 incidence wing relative stabilizer equal amount downthrust engine mount intend ed provide straight flight transmitter control inputs during vertical maneuvers gravity forces directed toward tail modeler likely concerned about incidence angles person prefers design scratch-build fac tory drawings three-view drawings means measurements taken directly subject aircraft modeler die-hard Scale purist insists upon copying fullsize prototype down last detail including incidence angles wing stabilizer numerous examples aircraft drastic angular differences much 60 Taylorcraft Staggerwing Beechcraft come mind result such setup down-load stabilizer high-wing cabin type also down-load tail due downwash off wing trailing edge case AC affected since total lift sum lift produced wing horizontal tail difference between two forces wing now must lift airplane weight plus stabilizer down-force AC now moves far forward positive longitudi nal stability CG must also moved far forward ahead AC Balancing such model favored 25% 30% wing chord doesnt assure stability particularly takeoff its first flight flier isnt prepared initial steep climb results stall snap roll crash disappoint ed modeler gathers pieces trash bag recommend reducing angular differ ence about 20 kits Spitfire full-size illustrated has 20 incidence wing 00 stabilizer 20 washout wing tip flier knows what expect large angular difference between wing stabilizer incidence built solidly fuselage structure cant easily changed model will have flown elevators drooping drastically experience know diffi cult hold Up elevator throughout first-flight 1748 AD GOES tWIN OUR BACK PA GE AD VERIISEAENT WORLDS 7 CH FM EXPERT len say own 7 diarmel 4 channel Expert FM tiei converson Systems say have 4 5 eliplanes want put receiver mdi eliplane era say tosterice yolfte diarmel 40 youl send franesltter will special line receivers VanenIlter -1 10 morethe nwnber exta receivers mares no ifleresce Retail pace therecelverls$8995Therewil odlwgelortrdngandwe1 pay outhozid freight have another franmeltrer diwnist 46 wait another mo&ie another receiver channel 4 thate eisa poselto hat cue have buy another tanmidlter mo&ie TranmnltW Mo6ie refi plc $4950 EXPERT 7 CHANNEL FEA TURES 1 Dual conversion FM erotIc 2 nicads chaiger 3 Reversing channels 4 Lodvng connectors 5 Dual rate aileron elevator 6 Mixing aileron & rudder elevator & Itapa 7 Servos use Mdstishi #15660 chp 8 ServOs use indirect drive 9 Excellent operation AM envimnment 10 Receiver uses ubra narrow band mufti-pole ceramic filters SERVO 52885 TJL sar LOClirda orweercrw JUSTARRIVEDI COMO 29 RIC Como 29 ie Ike eil engtoea tie cisro toe Sclsruerle pcrbd engtoe orankeliaft aipported doutoc bail beings 11w cano 29155 real powertdant planes like Woild Ennea Widoerd ARF comno 25 allwood Flince ARF rIta Retail plc Ccmo 29 $8495 JUSTARRIVED ZENOAHG-62 Zertoir 042 Isa 378 cikdc todrmagsetolrWonengtoethat toni power standpoInt drordd sqlivalent just tout eie thIs displacement tie madret 0-62 designed light weIrL lAilSer mont toduded lIds angita Retail pike tog pertonner $25985 EXPERT ACCESSORIES Shoen below ue acoessceles Expert FM ltoa cormectors selt-locidrig tyse prevent dtocorsiecton S-25 servo gaas wi avitla U2tfl 5weoTay fl fl I1i 2W1 Servo Ora Ii wAodg ousdor ss Rsa 0 ElEl iTS 24 5wvoEo-oi wAedJng onsiector $450 & ssou ReliC EiipsstNdx Step S59S Retodi NEW CHINA CLIPPER FROM ~TEH Sport version canopy town luIt consfruof Thgqran 5I 3-4 drarmela S- 40 sagne Otidrle 503 SMSS Reti WORLD ENGINES 0960 Rossash Ave cincinnati Ohio 45236 Phone 513 793-50OU Telex 214557 FAX 513 793-7337 August 1986 137 MABYCHI MOTOR $229 15 - 9 Volts HARRY B HIGLEY S SONS INC P 0 BOX 532 GLENWOOD ILL 60425