FREE FLIGHT INDOOR OLD BUSINESS previous column presented mystery photo taken Slanic Only Robert Dunham Tulsa Oklahoma correctly identified Erv Rodemsky Health Watch USIC As expected Jim Grant made back looking well always has also good see Jim Buxton flying HLG almost well before accident Before competition Jim expressed some doubt about well would working out consulted physical therapist about specific training As turned out very nearly won HLGonly fraction second behind Bernie Boehm longtime mentor Although Bob Champine hasnt flown Indoor several years returned year Bob long recovery serious stroke able fly several events Welcome back Bob Dick Hardcastle learned early year melanoma back cancer lung dual operation melanoma removed exploratory surgery done lung Dick said doctors cheered lung cancer wasnt melanoma removed lung Dick upbeat USIC flying several events getting stronger day very good prognosis Throw Age Bernie Boehm has obstacle want win Indoor HLG Nats year said needed get least 64 seconds match age started throwing some muscle pain worked through got 653 fourth toss arm back its top form went post top time 711 enough just beat Jim Buxton 4 second Nats win Site Records some speculation 50-minute flight might made years Nats almost happenedtwice John Kagan posted 4848 FID Larry Coslick posted 4848 Indoor Stick Steve Gardiner won Limited Pennyplane 1634 RepriseSpecific Impulse Previous columns have commented specific impulse rubber used Catapult gliders Specific impulse rate energy release coupled total energy release Some fliers have noted Tan II may best rubber use highest-energy rubber available because its very high stretch ratio up 101 has arms long enough Has anyone conducted specific instrumented tests various rubber batches measure specific impulse What constitutes good test specific impulse rubber HLG/Catapult Consistency several years have analyzed performance HLG Catapult fliers Indoor Nats trying better understand dynamics events analysis fliers performance consists dropping two lowest times averaging remaining scores flier has posted fewer five flights analysis gets pretty shaky use three best flights concept simple flier consistency score 98 higher getting model can deliver times dont win new glider needed year consistency lower recent studies year HLG Bernie Boehm 939 Jim Buxton 955 Robert Romash 589 Standard Catapult Ralph Schlarb 905 Bill Schlarb 977 Robert Romash 954 John Marett 898 Tem Johnson 951 Unlimited Catapult Bernie Boehm 988 Ralph Schlarb 973 Bill Schlarb 963 John Marett 884 Tem Johnson 90 MiniStick Postal Winner Walt Collins won 1999 MiniStick Postal event flights 801 829 good enough share details model flight strategies fit eightfoot-ceiling site Walts report details methodical test adjustment scheme can adapted Indoor models flew large meeting room St Joan Arc Catholic Church Yorktown Virginia Brainbusters have used site several years compete MiniStick Postal contest room about 25 feet wide 40 feet long dropped-tile ceiling flush lighting panels Most time during winter drift northwest corner southeast corner southeast corner exterior both walls allow steering site because its relatively large length width compared height approach try keep airplane ceiling long possible small circle avoiding walls much possible wing offset /8 inch combined seven-inch prop usually caused bounce off wall back room 122 Model Aviation other cellulose cement attaches prop hub Removable A-6 prop hub attaches shaft epoxy see text rather turn wall wingtip contact wingtip height also set 1/2 inch below prop radius prop would touch airplane design conventional 49% stab/rudder projected area twin rudders CG 75% flat center-section wing six inches 7 x 15 prop two most-important factors weight wing attack angle airplane built 43-gram minimum did perform well motor weight exceeded 39 gram including lube Since attack angle also critical wing cemented place tail boom tweaked optimize flight low-torque end flight basic setup about three degrees angle attack determined glide testing clay replacing weight prop motor glide testing done though 40-gram motor would used Weight added left wingtip adjust straight flight normal trim settings tail boom washout During powered testing tailboom raised until airplane would slow down much possible starting high-drag envelope airframe approaches stall correct angle attack airplane would dance up slightest heat appliances room attack angle too low airplane faster very stable ignored slight variations attack angle increased beyond point airplane seemed labor around circle sink badly torque ran out tests done fully winding motor backing off 500 turns before booking up launching airplane did climb 500 turns something needed changing attack angle problem motor size and/or prop pitch would changed After low-torque optimization done power increased thrustline adjusted left make circle diameter constant 10 feet small circle ensured plane would always approach wall small angle could bounce off final settings about three degrees left thrust almost no washout nominal torque primarily handled 3/ inch wing offset After hours cutting winding rubber well flight testing able identify rubber gave highest torque low end torque curve 2/98 Tan II winning flight used motor 105 inches long weighing 38 gram new After hard wind length about 11 inches motor wound 2400 turns no backoff airplane went vertical immediately after launch pirnuetted against ceiling would momentarily back off several times ceiling stopped prop fell back slightly After 45 seconds airplane stopped rotating started across room left wingtip down about 10 feet airplane righted itself began walking ceiling 10-foot-diameter circles drifting slightly toward cold corner Several lucky hits against ceiling kept airplane off walls latter part flight Prop stoppages ceiling impact inboard side room caused left wingtip drop resulting increased clearance wall next pass last ceiling bump about seven minutes very gentle trip floor eight feet took another minute-and-a-half Only about 150 turns remained motor An 801 flight made two weeks earlier similar profile flights during flying sessions lucky airplane getting trapped cool corner about five minutes luck important also Follow-Up F1D55 new rules FlD being investigated several fliers date 7/5/99 Steve Brown flying 10-inch-chord model fixed 20-inch prop Andres Hulais Argentina reported being pleased first efforts doesnt have suitable test site USIC Bernard Hunt flying six-inch-chord model about 130 square inches Richard Doig using AutoCad took two-inch-wide spanwise slice 65cm model scaled 55cmagain about 130 square inches A-6 Props little opportunity testfly no experience A-6 quandary about prop Most models have aluminum tube prop bearings makes prop changes troublesome photo shows solution grooved block attached prop shaft epoxy attaches model Another photo completes tale prop itself attaches hub Duco cement soaked loose hub allow prop change sure prop centered huh e ee maybe Santa needs hint WALSTON RETRIEVAL SYSTEMS 725 Cooper Lake Rd myrna GA 30082 770-434-4905 800-657-4872 Fax 770-431-0119 Visa AmEx e-nail WalstonRET@aolcom dont have yet. November1999 123
Edition: Model Aviation - 1999/11
Page Numbers: 122, 123
Edition: Model Aviation - 1999/11
Page Numbers: 122, 123
FREE FLIGHT INDOOR OLD BUSINESS previous column presented mystery photo taken Slanic Only Robert Dunham Tulsa Oklahoma correctly identified Erv Rodemsky Health Watch USIC As expected Jim Grant made back looking well always has also good see Jim Buxton flying HLG almost well before accident Before competition Jim expressed some doubt about well would working out consulted physical therapist about specific training As turned out very nearly won HLGonly fraction second behind Bernie Boehm longtime mentor Although Bob Champine hasnt flown Indoor several years returned year Bob long recovery serious stroke able fly several events Welcome back Bob Dick Hardcastle learned early year melanoma back cancer lung dual operation melanoma removed exploratory surgery done lung Dick said doctors cheered lung cancer wasnt melanoma removed lung Dick upbeat USIC flying several events getting stronger day very good prognosis Throw Age Bernie Boehm has obstacle want win Indoor HLG Nats year said needed get least 64 seconds match age started throwing some muscle pain worked through got 653 fourth toss arm back its top form went post top time 711 enough just beat Jim Buxton 4 second Nats win Site Records some speculation 50-minute flight might made years Nats almost happenedtwice John Kagan posted 4848 FID Larry Coslick posted 4848 Indoor Stick Steve Gardiner won Limited Pennyplane 1634 RepriseSpecific Impulse Previous columns have commented specific impulse rubber used Catapult gliders Specific impulse rate energy release coupled total energy release Some fliers have noted Tan II may best rubber use highest-energy rubber available because its very high stretch ratio up 101 has arms long enough Has anyone conducted specific instrumented tests various rubber batches measure specific impulse What constitutes good test specific impulse rubber HLG/Catapult Consistency several years have analyzed performance HLG Catapult fliers Indoor Nats trying better understand dynamics events analysis fliers performance consists dropping two lowest times averaging remaining scores flier has posted fewer five flights analysis gets pretty shaky use three best flights concept simple flier consistency score 98 higher getting model can deliver times dont win new glider needed year consistency lower recent studies year HLG Bernie Boehm 939 Jim Buxton 955 Robert Romash 589 Standard Catapult Ralph Schlarb 905 Bill Schlarb 977 Robert Romash 954 John Marett 898 Tem Johnson 951 Unlimited Catapult Bernie Boehm 988 Ralph Schlarb 973 Bill Schlarb 963 John Marett 884 Tem Johnson 90 MiniStick Postal Winner Walt Collins won 1999 MiniStick Postal event flights 801 829 good enough share details model flight strategies fit eightfoot-ceiling site Walts report details methodical test adjustment scheme can adapted Indoor models flew large meeting room St Joan Arc Catholic Church Yorktown Virginia Brainbusters have used site several years compete MiniStick Postal contest room about 25 feet wide 40 feet long dropped-tile ceiling flush lighting panels Most time during winter drift northwest corner southeast corner southeast corner exterior both walls allow steering site because its relatively large length width compared height approach try keep airplane ceiling long possible small circle avoiding walls much possible wing offset /8 inch combined seven-inch prop usually caused bounce off wall back room 122 Model Aviation other cellulose cement attaches prop hub Removable A-6 prop hub attaches shaft epoxy see text rather turn wall wingtip contact wingtip height also set 1/2 inch below prop radius prop would touch airplane design conventional 49% stab/rudder projected area twin rudders CG 75% flat center-section wing six inches 7 x 15 prop two most-important factors weight wing attack angle airplane built 43-gram minimum did perform well motor weight exceeded 39 gram including lube Since attack angle also critical wing cemented place tail boom tweaked optimize flight low-torque end flight basic setup about three degrees angle attack determined glide testing clay replacing weight prop motor glide testing done though 40-gram motor would used Weight added left wingtip adjust straight flight normal trim settings tail boom washout During powered testing tailboom raised until airplane would slow down much possible starting high-drag envelope airframe approaches stall correct angle attack airplane would dance up slightest heat appliances room attack angle too low airplane faster very stable ignored slight variations attack angle increased beyond point airplane seemed labor around circle sink badly torque ran out tests done fully winding motor backing off 500 turns before booking up launching airplane did climb 500 turns something needed changing attack angle problem motor size and/or prop pitch would changed After low-torque optimization done power increased thrustline adjusted left make circle diameter constant 10 feet small circle ensured plane would always approach wall small angle could bounce off final settings about three degrees left thrust almost no washout nominal torque primarily handled 3/ inch wing offset After hours cutting winding rubber well flight testing able identify rubber gave highest torque low end torque curve 2/98 Tan II winning flight used motor 105 inches long weighing 38 gram new After hard wind length about 11 inches motor wound 2400 turns no backoff airplane went vertical immediately after launch pirnuetted against ceiling would momentarily back off several times ceiling stopped prop fell back slightly After 45 seconds airplane stopped rotating started across room left wingtip down about 10 feet airplane righted itself began walking ceiling 10-foot-diameter circles drifting slightly toward cold corner Several lucky hits against ceiling kept airplane off walls latter part flight Prop stoppages ceiling impact inboard side room caused left wingtip drop resulting increased clearance wall next pass last ceiling bump about seven minutes very gentle trip floor eight feet took another minute-and-a-half Only about 150 turns remained motor An 801 flight made two weeks earlier similar profile flights during flying sessions lucky airplane getting trapped cool corner about five minutes luck important also Follow-Up F1D55 new rules FlD being investigated several fliers date 7/5/99 Steve Brown flying 10-inch-chord model fixed 20-inch prop Andres Hulais Argentina reported being pleased first efforts doesnt have suitable test site USIC Bernard Hunt flying six-inch-chord model about 130 square inches Richard Doig using AutoCad took two-inch-wide spanwise slice 65cm model scaled 55cmagain about 130 square inches A-6 Props little opportunity testfly no experience A-6 quandary about prop Most models have aluminum tube prop bearings makes prop changes troublesome photo shows solution grooved block attached prop shaft epoxy attaches model Another photo completes tale prop itself attaches hub Duco cement soaked loose hub allow prop change sure prop centered huh e ee maybe Santa needs hint WALSTON RETRIEVAL SYSTEMS 725 Cooper Lake Rd myrna GA 30082 770-434-4905 800-657-4872 Fax 770-431-0119 Visa AmEx e-nail WalstonRET@aolcom dont have yet. November1999 123
