CONTROL LINE AEROBATICS IM GOING TO continue technology discussion month So far Ive looked composites structures power plants contrast between now far have come astounding happened see original drawings Don Stills 49 Nats-winning Stunter other day really surprised contrasts design huge wing short-short coupling semi-molded fuselage construction take-apart wing construction true D tube George Aldrich says may first Stunter use type construction maneuvers under 300 speed well over 90mph George said hot combination late forties After looking drawings some others George Ive finally reached same conclusion others have should have procedure approve additional designs Old-Time competition After worthy designs era deserve see light competition proper documentation can still maintain spirit event looked Don Stills design saw little comparison side view later designs tiny super cycle look wing D-tube construction aside alifoil size 696 square inches ballpark current designs fully sheeted fuselage developed easy construction George says its no big stretch compare much-later molded-shell efforts point derived bit history much learned past pioneers event An often-paraphrased quote applies unaware history doomed repeat next big advance may sitting out waiting become relevant piece puzzle also numerous examples crossing technology other model fields Consider Frank Williams unusual motor front-exhaust rear-drum valve 05 40 basically RC boat engine Tuned-exhaust systems used FM Speed models really came two-stroke motorcycles Modern aircraft technology gave us composite materials new adhesives quest performance has really begnn years have occasional attempts significantly increase retracting gear performance Harold Price made earlier attempts Crusader design enjoyed limited success because mechanical design retraction systems late fifties through late seventies rumors leading fliers seriously considering retracting gear project Bob Hunt looking deferred Al Rabe Sea Hornet primarily designed retract system however stopped competing before completed project time wasnt satisfactory retraction mechaaism available over counter control retraction cycle solved Al going design fabricate entire system Hornet sits storage Recently several competitors reopened case Bob Whitely has prototype system working classic Rabe Mustang demonstrated system Vintage Stunt Championships VI certainly looked September1994 111 Ward Vanduzers Electra based Hunt USA-i wing Vectra numbers Elis homebullt 91cc AAC Limbo non-Schnuerle design 13 ounces muffler Bolly three-blade 12 x 61A Allen Brlckhaus 690-sq 61-oz Savoy Piped OS 46VP Pormula U fuselage MonoKote wings PP6 DAU 75 clear Eli Rozenbergs Limbo 1700 grams 700 square inches Two-part Du Pont finish Eli flies Israels national team AMA members now eligible prestigious FAI Air Crew Card identifies pilot airport tendants police security guards can open door crew dis counts hotel rooms meals other perks FAI photo ID card issued National Aeronautic Associa tion NAA umbrella organization major air sports groups includ ing AMA sole US representa tive Fd6ration A6ronautique Internationale FAI Support sport sport will support Oshkosh Special Get FAI photo ID wait Oshkosh Convention Meet NAA AVEMCO Tent E Aviation Alley tween Fly Market Flight Line well take picture prepare ID card spot use handy cou pon below -I lcerti am member AMA pilot United States FAA pilots license # ________________ photocopy license passport-1 size photo have signed revers enclosed Please issue FAI Air Crew rd valid period indicated I1year l2years U3yearsI $19$29 Please complete return check money order charge credit card II signatureI I Name printI I AddressI II II II II II II INational Aeronautic AssociationI 1815 N Fort Myer Drive Ste 700 lington VA 22209I L 3527-0226 cityState Zip l Visa 0 Mastercard Credit Card #Exp Date impressive flight locked groovy retracts commercial RC units brains system Jomar Autoretract Servo controller Bob worked Jomar define requirements 3Ao-ounce unit controls retract servo battery powers both servo controller switch activates umt After adjustable delay between five 15 seconds servo retracts gear engine running controller monitors engine tiny microphone mounted circuit board drops gear engine stops Bob Hunt also has prototype retraction system has working completely different design several years Airworthiness has proven remains constructing competitive airframe design paper some work has done actual construction As anyone has explored retracting gear knows design installation trivial Bob using lost foam technique originated develop rib sections after locating retract mechanisms look forward seeing retracting-gear models competition evaluate competitive edge After positives negatives evaluated Theres no question considerable drag eliminated sucking gear other hand weight penalty associated mechanisms power pack Bob Whitely says weight increase between five seven ounces Bob Hunt says system should approximately half design considerations least significant change vertical center gravity occurs upon retraction Bob Hunt has made adjustment looking totally inline configuration may ideal situation since hasnt much testing dont know sure However competitive components now exist perhaps widespread use will develop retracts untillike tuned pipe models use limited experience however biggest performance gains achieved still propellers have never felt instant airplane effect havent lived vividly remember first time felt Hi Johnson gave Y&O 10 x 6 try 58 Nationals everything improved immediately vertical line tension corner etc just amazing After broke prop could never get quite same feel again Some years later prop ST 60 model although never seemed work Texas another story up north flew three Nationals finally breaking team trials highly thinned repitched Although have tried numerous occasions duplicate itand did thousandth inchthose efforts did yield same results Perhaps wood good prop flexed certain way movement carbon-fiber props eliminates variations props caused different grains carbon/epoxy configuration also significantly stiffer other materials Therefore props can thinner efficient real question work Bollys Eathers answer yes sometimes takes work fliers part tailor props specific model Now props have around various forms number years idea can repitched using heat soften epoxy significant essentially can cut dried being able return baseline carbon has memory reapplying heat returns molded pitch Make no mistake altering propeller assumes risk because manufacturer certainly voids warranty Although would unrealistic say l21i x 43/4 prop prop ST 60 model its probably good candidate can suggest work what competitive fliers use significant performance gained pursued perhaps increase Ive discussed senes Refer discussion low-pitch series props previous columns proven approach deserves attention Workshop News No model workshop complete new airplane ceiling fans now available Several companies making neat Hunter makes Navy Corsair Nose another P-40 Nose carried Sams Check out Model Aviation 4The Most Complete Line Precision Bench Top Metalworking Equipment LOCAL SERVICELATHES S SSORIES LOCAL PARTS SpindleLhe Mill racyCo,bo Total MachInIng Cent Accepts Watchma.CoIlet Coot Hi235c 000Ccr 000 Hlgh Accuracy 10 4The Demanding al Beft IT0dM
Edition: Model Aviation - 1994/09
Page Numbers: 111, 112
CONTROL LINE AEROBATICS IM GOING TO continue technology discussion month So far Ive looked composites structures power plants contrast between now far have come astounding happened see original drawings Don Stills 49 Nats-winning Stunter other day really surprised contrasts design huge wing short-short coupling semi-molded fuselage construction take-apart wing construction true D tube George Aldrich says may first Stunter use type construction maneuvers under 300 speed well over 90mph George said hot combination late forties After looking drawings some others George Ive finally reached same conclusion others have should have procedure approve additional designs Old-Time competition After worthy designs era deserve see light competition proper documentation can still maintain spirit event looked Don Stills design saw little comparison side view later designs tiny super cycle look wing D-tube construction aside alifoil size 696 square inches ballpark current designs fully sheeted fuselage developed easy construction George says its no big stretch compare much-later molded-shell efforts point derived bit history much learned past pioneers event An often-paraphrased quote applies unaware history doomed repeat next big advance may sitting out waiting become relevant piece puzzle also numerous examples crossing technology other model fields Consider Frank Williams unusual motor front-exhaust rear-drum valve 05 40 basically RC boat engine Tuned-exhaust systems used FM Speed models really came two-stroke motorcycles Modern aircraft technology gave us composite materials new adhesives quest performance has really begnn years have occasional attempts significantly increase retracting gear performance Harold Price made earlier attempts Crusader design enjoyed limited success because mechanical design retraction systems late fifties through late seventies rumors leading fliers seriously considering retracting gear project Bob Hunt looking deferred Al Rabe Sea Hornet primarily designed retract system however stopped competing before completed project time wasnt satisfactory retraction mechaaism available over counter control retraction cycle solved Al going design fabricate entire system Hornet sits storage Recently several competitors reopened case Bob Whitely has prototype system working classic Rabe Mustang demonstrated system Vintage Stunt Championships VI certainly looked September1994 111 Ward Vanduzers Electra based Hunt USA-i wing Vectra numbers Elis homebullt 91cc AAC Limbo non-Schnuerle design 13 ounces muffler Bolly three-blade 12 x 61A Allen Brlckhaus 690-sq 61-oz Savoy Piped OS 46VP Pormula U fuselage MonoKote wings PP6 DAU 75 clear Eli Rozenbergs Limbo 1700 grams 700 square inches Two-part Du Pont finish Eli flies Israels national team AMA members now eligible prestigious FAI Air Crew Card identifies pilot airport tendants police security guards can open door crew dis counts hotel rooms meals other perks FAI photo ID card issued National Aeronautic Associa tion NAA umbrella organization major air sports groups includ ing AMA sole US representa tive Fd6ration A6ronautique Internationale FAI Support sport sport will support Oshkosh Special Get FAI photo ID wait Oshkosh Convention Meet NAA AVEMCO Tent E Aviation Alley tween Fly Market Flight Line well take picture prepare ID card spot use handy cou pon below -I lcerti am member AMA pilot United States FAA pilots license # ________________ photocopy license passport-1 size photo have signed revers enclosed Please issue FAI Air Crew rd valid period indicated I1year l2years U3yearsI $19$29 Please complete return check money order charge credit card II signatureI I Name printI I AddressI II II II II II II INational Aeronautic AssociationI 1815 N Fort Myer Drive Ste 700 lington VA 22209I L 3527-0226 cityState Zip l Visa 0 Mastercard Credit Card #Exp Date impressive flight locked groovy retracts commercial RC units brains system Jomar Autoretract Servo controller Bob worked Jomar define requirements 3Ao-ounce unit controls retract servo battery powers both servo controller switch activates umt After adjustable delay between five 15 seconds servo retracts gear engine running controller monitors engine tiny microphone mounted circuit board drops gear engine stops Bob Hunt also has prototype retraction system has working completely different design several years Airworthiness has proven remains constructing competitive airframe design paper some work has done actual construction As anyone has explored retracting gear knows design installation trivial Bob using lost foam technique originated develop rib sections after locating retract mechanisms look forward seeing retracting-gear models competition evaluate competitive edge After positives negatives evaluated Theres no question considerable drag eliminated sucking gear other hand weight penalty associated mechanisms power pack Bob Whitely says weight increase between five seven ounces Bob Hunt says system should approximately half design considerations least significant change vertical center gravity occurs upon retraction Bob Hunt has made adjustment looking totally inline configuration may ideal situation since hasnt much testing dont know sure However competitive components now exist perhaps widespread use will develop retracts untillike tuned pipe models use limited experience however biggest performance gains achieved still propellers have never felt instant airplane effect havent lived vividly remember first time felt Hi Johnson gave Y&O 10 x 6 try 58 Nationals everything improved immediately vertical line tension corner etc just amazing After broke prop could never get quite same feel again Some years later prop ST 60 model although never seemed work Texas another story up north flew three Nationals finally breaking team trials highly thinned repitched Although have tried numerous occasions duplicate itand did thousandth inchthose efforts did yield same results Perhaps wood good prop flexed certain way movement carbon-fiber props eliminates variations props caused different grains carbon/epoxy configuration also significantly stiffer other materials Therefore props can thinner efficient real question work Bollys Eathers answer yes sometimes takes work fliers part tailor props specific model Now props have around various forms number years idea can repitched using heat soften epoxy significant essentially can cut dried being able return baseline carbon has memory reapplying heat returns molded pitch Make no mistake altering propeller assumes risk because manufacturer certainly voids warranty Although would unrealistic say l21i x 43/4 prop prop ST 60 model its probably good candidate can suggest work what competitive fliers use significant performance gained pursued perhaps increase Ive discussed senes Refer discussion low-pitch series props previous columns proven approach deserves attention Workshop News No model workshop complete new airplane ceiling fans now available Several companies making neat Hunter makes Navy Corsair Nose another P-40 Nose carried Sams Check out Model Aviation 4The Most Complete Line Precision Bench Top Metalworking Equipment LOCAL SERVICELATHES S SSORIES LOCAL PARTS SpindleLhe Mill racyCo,bo Total MachInIng Cent Accepts Watchma.CoIlet Coot Hi235c 000Ccr 000 Hlgh Accuracy 10 4The Demanding al Beft IT0dM