Control Line: Aerobatics

CONTROL LINE AEROBATICS month Im going continue assembling typical Stunter focusing wing/fuselage installation before get thought Id write few words importantif criticalto latest creation might have heard fervent wish build light straight Well add better straight light within reason heres airplane built correctly chances good will able trim fly reasonably well An airplane out alignment will never fly its full potential compensating trim fighting improper alignment times Ive let mindset looks good enough overcome good sense Only correct alignment acceptable model Any time invested ensuring justified Getting Wing Fuselage wing installed basic fuselage crutch brings up point Ive mentioned times various actions just important convenient time fuselage work before install wing much easier carve blocks fine detail work etc having concemed large structure prone dings Complete entire fuselage point just prior finishsanding should include mating shaping top bottom blocks detail work cowling proceeding far possible Any cockpit work can completed convenience fuselage top subassembly can go no farther strip fuselage back basic crutch Now youre ready mount wing start venture emphasized good procedure will ensure accurate alignment heres cut wing assembly point bottom fuselage sides cut provide insertion wing rather fragile crutch positioned over series layout lines have evolved trued flat assembly table has cork covering ruled provide references have centerline perpendicular lines wing hinge lines assuming straight hinge line stabilizer hinge lines work surface covered A-inch plate glass Using centerlines marked fuselage formers crutch positioned over centerline trailing edge points positioned over intersecting perpendicular reference lines correctly aligned use CyA cyanoacrylate glue tack-glue work surface can easily released end sequence debonder raw nitromethane Did remember dress off crutch top sits flat What have now like blank page final exam key process honest airplane wonder airplanes described having unequal turns have characteristic built during process am discussing relatively easy say precut kit get thrust stabilizer reference lines out alignment concentrating fit wing forgetting fragile stage other factors can move again good procedure important So working flatand mean triple-checked-flat surface glass plate can shimmed playing cards reference plane height measurements Make up mind what point will exact can make no matter long process takes suggest well-rested allocate adequate time worst approach being willing accept good enough isnt correct have wasted time already spent time come Take look wing should minimum finish-sanded controls installed complete Some excellent builders prefer have wing covered finished through silver point As much building process however need try various approaches whats comfortable Before drop wing trim fit get some reference lines fuselage sits alignment fixture plans measure distance crutch top thrustline Transfer distance leading edge cutout both sides rear same stabilizer centerline 124 Model Aviation eous Big Jim Patternmaster Gary Lutz Big Jim ST 60 pulls 70-ounce model well Windy Urtnowski photo Continued page 126 Bill Richs Astra progress Striking color scheme good pattern display won Byron paint stand FAI fund-raiser Gerald Clarks Sig Super ChipmunkMagnum 40 68-foot lines Modification RC kit instead familiar CL Stunter either side linkages can get complex usual single-engine model Most schemes Ive seen use standard throttle arm belicrank fore-and-aft movement arm changed spanwise movement 900 bellcrank fuselage direction changes again engine nacelles additional 900 belicranks number belicranks can introduce play system add complexity weight necessary possible save weight produce more-direct linkage connecting throttle pushrods directly throttle arm leadout attached standard three-line bellcrank still required throttle arm bellcrank pushrod would normally connected ignored alternative does away inboard pushrod entirely connects inboard 900 bellcrank directly throttle leadout cable continuing throttle arm line slider option less practical Scale model because effective line lengths throttle elevator would change relative another slider moves like electronic throttle control would find twin installation relatively easy Flexible cable-and-sleeve pushrods less practical conventional throttle control twins because extra resistance introduce two pushrods required servtr driving throttles friction linkage much less consideration flexible pushrods would simplify linkage considerably eliminating bellcranks used change directions control movement key successful installation flexible pushrods ensuring both ends outer sleeve securely attached aircraft structure ends sleeve can move result similar having spring part otherwise rigid pushrod National Air Space Museum Web site great place visit QT Sightings section offers movie clips historical interest offerings December written included two clips takeoff landing C-130 carrier trials USS Saratoga Its interesting viewing say least no arresting gear used C-130 cant really considered prototype events C-130 used anti-skid reverse thrust stop home page http//wwwairspacemag com Navy Carrier events Nationals Nats will flown July 15-17 Profile Carrier begins activities Thursday July 15 Class land Class II Friday Saturday July 17 will reserved unofficial Carrier events would like participate official help other way running Carrier events please contact Navy Carrier Society president Bill Calkins 630 4661531 write him 317 Snow St Sugar Grove IL 60554 Nostalgia Navy Carrier has flown unofficial event Nats last two years summer effort increase participation Ive changed rules require designs existed prior 1978 Within limitations cited rules such fixed leadout position flight model may used bonus will used encourage Nostalgia-era models special award memory Roland Baltes will presented model modeler best representing spirit event Nostalgia event flown using scoring system existed prior rule change January 1976 interested competing please let know sufficient interest Ill include separate Class Class II events addition Profile will other unofficial events flown Saturday July 17 addition Nostalgia Carrier Navy Carrier Society will sponsor Sportsman Profile Carrier modelers did enter official Carrier events As past Skyray Carrier 15 Carrier can also expected will provide rules unofficial event anyone asks erobaticslMcMillan Continued page 124 stage because now fuselage stabilized flat reference surface measurements will identical Consider making references permanent wont sanded off finishing process Should have mishap future could very handy have reference marks available instance pancaked alrplane damaged wing cut out bottom fuselage installed new wing replaced bottom cutout refinished affected area Its time first trial fitthere will probably Position wing center planform fuselage centerline See trailing edge perpendicular reference line tip tip Have checked trailing edge straight looks okay see alrfoil centers leading trailing edges rest relation reference marks force wing daring fitting process Ideally wing should rest correct alignment should slow careful mode work up perfect fit wing centerlines above marks will have remove material wing sets up fuselage closer table will have add strips balsa difficult process tedious patient After think have setup pretty close its time install alds use series trued balsa blocks serve positioning fixtures alignment tools blocks marked line precisely height wing centerline building surface positioned along trailing edge reference line CyAd table Drop wing back fuselage check aligmnent wing set fuselage marks should line up should trailing edge centerline lines trailing edge blocks everything checks fine figure out whats out alignment Before removing material recheck reference remeasure everything what necessary correct problem Dont push wing alignment Go slowly have set add another set blocks same reference lines leading edge wing positioned wing existing fixture glued building surface snug up against leading edge youve done job far ahgnment marks should jive up tip tip Recheck recheck recheck Make sure wing fits snugly under pressure its fixture everything lined up Look again wing joint fuselage sides best can create good-fitting seam point wanted reach has taken long glue critical joint like use slow-set epoxy paint both surfaces glue wipe off After apply another coat wing goes Tack place use few T-pins maintain alignment Recheck everything remove excess epoxy Recheck several times next few hours Its best let assembly rest overuight next day rested preceding process look everything can still make adjustments have better now later something slipped what have to fix may include taking wing off Assuming everything checks out can start encapsulating wing Dont take assembly off fixture until have added cut-out pieces Put doublers Ys plywood plates over trailing edge add formers suggest using existing cutouts pattern new ones will undersized Take last look structure before remove fixture have choice popping structure loose #26 XActoTM blade prefer using Q tipsTM nitromethane debond CyA Use what required release bond Finish wing joint top complete other detailed tasks such top formers leading edge-to-mainframe wall joints What should have now wing correctly installed fuselage procedure use copy fully use whatever portions suit works Model Aviation