Radio Control: Sport-Aerobatics

[IIiSporFAerobatics EJRon Van Pulte ONCE IN new product tech nique comes out really shakes up RC hobby development digital proportional such advancement Still other new products techniques may quite earthshaking promise solid advancement far reaching effects What call Giezen danner potentiometer wiper assembly new potentiometer wiper developed Bruno Giezendanner Switzerland RC aero batic world champion 1969 1971 Precision aerobatic competition requires extremely accurate reliable servo oper ation severe environment characterized high vibration levels heavy g loadings Most pattern fliers have discovered servo potentiometer wear biggest problems must contend maintaining competition airplanes potentio meter wiper element begins wear servo gets nervous centering unrelia ble Some pattern fliers have found must clean lubricate replace potentiometer elements ten flights order remain competitive problem caused beryllium copper potentiometer wiper used servos wiper spring loaded make good electrical contact potentiometer element friction tween wiper element causes relatively soft carbon element wear sufficient wear has occurred servo thinks several different outpUt arm positions electrically same results nervous action and/or poor centering servo What Bruno Giezendanner has done develop new wiper assembly cludes small piece material acts interface between wiper potentiometer element interface ma terial tiny truncated cone fits small hole wiper spring force between wiper assembly ele ment keeps conical interface coming out hole new wiper assembly cuts potentiom eter element wear minimum servo maintenance need done after hun dreds flights instead tens flights Some pattern fliers have claimed no detect able potentiometer element wear after 200 flights Regardless actual long-term performance new product has clearly demonstrated can make aircraft system maintenance lot easier Giezendanner potentiometer wiper assembly being distributed coun try Pro Line Electronics 10632 N 21st Ave Phoenix AZ introduced servos October 14 Pro Line also has replacement wipers $280 R/C South Route 3 Box 43 Nims Lane Pensacola FL 32504 also has Giezendanner wiper $300 apiece R/C Continued page 87 January 1978 21 Among past champions World Championships Springfield Bruno Giezandanner won 1969 1971 also Swiss champ 10 times ST 60-powered 63in Scorpion its distinctive wing planform designed Bruno brother Emil Own electric retracts PeckPolymers Mini-Bell real bell-ringer 02 power 1/3-scale version Goldberg Senior Falcon Liberty Bell Span 26 two- three-channel radio Japanese team manager just autographed World Championships official programa popular customwhen picture snapped Sleek looking model ready box belongs Okumura fundamental items Transmitter Tests First obvi ous Try switch knob pushbutton control stick trim lever find out doing what should take system outside perform range check described manual came system general dislike range checks cover less about 50 feet ground range because its too hard detect changes shorter ranges have systems calls 9- 10-foot ground range test antenna transmitter collapsed much possible antenna disap pears inside transmitter case test first section pulled way out Measure ground range terms paces length stride walking normally See last months column additional details Next charge transmitter pack fully extend antenna full length note time turn transmitter night wont shooting someone down its raining snowing Note output meter reading Now go something else Check output meter hour Note time falls half-scale calculate elapsed time new system operates 4 hours can expect moderately-used system drop about 3 hours after 5 years happens buy yourself new transmitter battery pack time shortens much less 5 years probably have least shorted cell pack should replaced Recharge transmitter set aside Receiver Servo Tests testing transmitter should have noticed servos jumping sticking running noticeably slower others find mark piece tape description prob lem stick servo Try swapping servos around prove trouble servo transmitter receiver have servo tester can help pinpoint troubles Repairs matter deciding whos going ityou factory local service center event convinced receiver needs retuning might check circuit discover two coils output end cir cuit ones likely need adjustment antenna coils rarely shift enough warrant readjustment Make tuning wand like described page 12 September 1977 column tune best ground range very important point about retun ing no value attempting retune receiver being disturbed noisy servo have jittery servo probable cause loose dirty wiper potentiometer feedback potentiometer electrical noise results such condition can easily cut ground range half Without getting technical about reason range reduction AGC Automatic Gain Con trol action within receiver response servo noise Therefore use good servos tuning Receiver Battery Tests subject has done death recent years Buy borrow battery analyzer test battery pack performance 25% below normal find out fix replace pack new battery pack cheapest insurance can buy continued happy flying Summary discussion has delib erately kept very simple just convince you can will perform simple maintenance chores described above guarantee will fly longer better next year have fun doing dont have electron ics technician take proper care equipment George Myers 70 Froehlich Farm Rd Hicksville NY 11801 RC Aerobatics/VanPutte continued page 21 South run Steve Helms well known pattern flier out standing work did Pro Line January1978 87 5MUF-L-ITSERIESNEW PRODUCTS ISTON SETTING TOOL ST FOR EVERY CLUB / MUFFLER/SIh CAR MUFFLER K& B 35ccuiienuwiC CLEANER21 QT 16500 Mufflers s zeENGINE MOUNTS Schnue le09 15 379NOTE cog r1e1SK4B 459SEE YOUR 1925395DEALER FOR 2940489PRICE OF 6080859MOUNT FOR YOUR ENGINE 1150to1795FACTORYFOR NOSE GEARSOR SEND TO CALIJMET SERIES MUFFLERS BATTERY CHARGER See yir dealer no dealer 10100 convenient order direct SCALE INSTRUMENT KITSSer 25C ccxtJete catalno 56 3/B TIMERS 7 6 1 2 FUELCUTOFFlISOENGINETEST ALLSIZES 279DETHERMALIZER 1150STAND 865Tatan Products Corp SOC OSNUVA Ave THE WORLD S LARGEST LINE OF MUFFLERS AND ENGINE MOUNTS AN FSANCCO CA GRISH AIRCRAFT TYPE PROPELLERS Made hardwood fully carved true helical pitch airfoil ready sanding 18$700ALL SIZES IN 208008 & 10 PITCH 221000RIGHT HAND 241300ROTATION 3/8 BOREUSE TO PROPEL AIR CREATE THRUST BE PROPELLED BY AIR ELLERS ALL GRISH PROPELLERS ARE ENGINEERED TO TRUE HELICAL PITCH FOR EFFICIENCY 2 Blade Tractor2 Blade Pusher 304 354 504 654 854 Si $150 Made polyester boll color Kraft ran Signature Series production line initial shipment 300 wipers probably gone now am sure will have way FELLOW EGLIN AERO MODELLER editor club newsletter Ed Moorman guy refuses fly pattern contests claims boring Instead has developed techniques doing hot dog maneuvers October 1977 Radio Con imi Modeler magazine contains article some techniques Com pared fliers Eds flying very ex citing example almost always per forms roll immediately after takeoff often does split-S landing Recently practicing low inverted flying got tad too low just touching tip vertical fin runway Since theres no way recover situation airplane proceeded settle down runway ended up thoroughly sanded canopy engine head fins Undaunted mounted small wheel tip vertical fin nose gear top fuselage just behind engine vertical fin touches runway now airplane rolls stop Ed working extending nose gear can perform inverted touch-andgo maneuvers An interesting sidelight experience claims have lost fear flying inverted low ground finds very easy maintain less foot ground clearance long AT DISCRETION OF THE PURCHASER distances down runway still scares heard about interesting pattern contest Huntington County Indiana Modelers sponsored August Contest Director Pat Shuttleworth reported Beginner Pro-Am event first-time contest fliers went like Beginners drew Masters fliers name hat became caller-coach Beginner Beginners -flew round mistakes blamed coach naturally Masters flew Beginners airplanes around really enjoyed watching partici pating winner selected adding Beginners best two scores coachs best two scores sounds like fun wonder got enough NOTICE CE CE December issue schematic Hugh Shoemaker servo testerde scribed Ron VanPuttes column SportAerobaticswas inadvertently omitted schematic will printed February issue NOTICE CENOTICE V writing advertisers mention read about MA Masters level fliers go around contests around country now offer ing Beginner events have proved very popular sometimes malicious sense humor recently tickled anonymous ventor offered new device fliers still believe steady wind actually affects flight aircraft inven tion based fact often hears flying field namely airplane turns upwind climbs turns downwind dives inventor proposed device senses aircraft rate climb transmits signal ground-based flier device detects maximum positive rate climb airplane heading directly wind maximum negative rate climb indicated airplane heading directly downwind carefully flying steady turn flier can tell direction wind blowing love inventor also working perpetual motion machine Since mentioning Fun Fly events couple columns have received several letters readers suggested events would like share some Don Jenkins Indianapolis Indiana sent letter typed single spaced both sides piece paper thats lot words described mod eling activity since starting during 1930s went present some low key events club Hamilton R/C Mod elers use because goodly number junior/senior muddlers like have real knowledgeable board direc tors have set up some very basic events 1 Timed Flight Timer tells entrant long must stay air aid watch someone counting off sec onds Time starts wheels leave ground stops wheels touch down usually flight between 45 seconds two minutes depending wind weather conditions Closest stated time wins 2 Power Flight vs Glide Flight Entrant picks time wants climb under power cuts engine off glides long possible Best glide power ratio wins 3 Bomb Drop described drop since have using spools worn out batteries hope someone else sees suggestion using tiny flour bags have advocated long time because hard objects bounce roll flour bomb explodes Makes easier determine closest drop 4 Figure Eight Touch Go Take off fly end area around pylon touch go fly opposite end area around pylon etc until amount laps has completed Best elapsed time wins way Don looking another O&R 19 replace old has finally run out know engine col lector would trade runner per88 Model Aviation 52 5-45A-35A-45-4 6-36-4 354 6-36-48-6 854 7-4767-89-610-6 Si 8-4868-83 BladeTractor 9-4969-75-3 6-36-4 504 9-810410-6 11-411-611-8 12-412-512-6 Os G RUSH ST JOHN INDIANA 46373 3 Blade Pusher AT YOUR DEALER BLADE 0 6-35OIjg Metallic Aluminum Coloi fT7678 $1 ractor ATYOuRDEALER8688 $125 9-610-610-4 $150 Pusher 10-6$150 feet show specimen have need flyable engine because guts oldies practically non-existent would like arrange trade write Don Jenkins 2915 E 65th St Indiana polis IN 46220 letter Dick Phillips sent Prince George British Columbia contained what Dick called Fun Fly idea #476B Place Dixie cup model ala bomb drop contestant issued ten jelly beans navy beans lima beans smarties whatever areRVP placed cup prescribed series maneuvers flown example Takeoff Figure Eight Approach Land K-Factor func tion maneuvers times number beans still cup contestants score series maneuvers can related pilots skill level Im still lookout good Fun Fly ideas about sharing yours rest us Ron Van Pune 12 Connie Dr Shah mar FL 32S79 RC Scale/Wischers continued page 22 freon actuated retracts very similar average scale planes plane dif fered average respect values moment inertia about roll pitch axis reduced special construction techniques change important us would like avoid unexpected surprise spin low level snap roll Light strong construc tion especially near tail wing tips essential element model fuselage laminates fiberglass cloth impregnated resin wings balsa covered fiber glass resin weight kept mini mum squeezing laminates molding process because resin con tributes little strength Tail s4rfaces wing tips made balsa free-foam ing plastic light weight Ballast added place center gravity desired location bring weight up desired 16 pounds engine test model stand ard 61 completely cowled scale planes same problem encoun tered us similar situations overheated answer would control airflow through ducts baffling NASA engineers chose dif ferent approach added large heat sink engine consisted four large circular aluminum fins attached tightly cylinder Because spin tests would permit large center gravity excursions fuel tank lo cated CG pressure system regulator employed interesting aspects tests telemetry method returned information ground means seven-channel model type transmitter case board plane re layed signals seven sensors measur ing angle attack side slip control positions hobby receiver ground servos operating potentiometers recording oscillograph Another technique has used modelers should used ten practice utilizing second plane similarly loaded gain experience before flying plane may have taken years build Start tests practice plane loaded lightly add weight until heavy finished scale model will pilots used method good effect since landing speed creased greatly during time weight being increased found run way 1000 feet long 100 feet wide required Piper tests conducted twin 60-powered /6-scale 15-lb plane righthand Supertigre engine modified rotating front bearing give opposite rotation tests also em ployed two pilots spin recovery chute Like NASA plane fiber glass fuselage two layers cloth nose wing trailing edge layer tail polyurethane foam wing core covered 3/32 balsa fin ished fiberglass cloth epoxy resin retract gear powered dessi January1978 89