Free Flight: Old-Timers

FREE FLIGHT OLD-TIMERS 11 U t U fJ iu ra n HAVE ANSWERS two mysteries am referring quest designer Testor Endurance Hand-Launched Glider HLG 1940s ignition coil polarity issue Floyd Caner walks walk well talks talk set up experiment dealing polarity Note double-pole-double-throw slide switch see photo cross-wired can instantly change polarity power supply battery engine runs first determined switch position HV pulse HV arted engine set stable twocycle run about 4000 rpm starting voltage V 32 switch tion After wann-up slowly reduced voltage regulated power supply until engine began miss weak spark ffipped switch HV miss went away Encouraged tried times sometimes starting HV position sometimes HV position repeatable time other significant result wasnt very much difference power supply voltage adjusting lower voltage started make motor miss difference about 03 V missing started 22 V HY started 25 V HV doesnt seem like claimed 20-40% difference yet difference thesis commercial spark coils way over-designed operate Ni-Cd cells dont sag until almost dead So looks like difference slight significant operation Carter calculates 12% efficiency difference concludes spark systems have lots margin never have worry about operating region spark performance dictated hot electrode effect certainly have argument simple experiment Carter assumes use three Ni-Cds interpretationI used use two other Free Flighters Starting nominal 24 volts instead 36 wonder 12% significant difference model poor runs engine missed failed recharge admittedly small-capacity Ni-Cds after two three flights need advantage 1cm get Dick Mathis remember Fast Richard once said ignition motor greatest torture device ever invented beeause always seemed about work right never did Coil polarity described September column does make difference huge difference claimed anyone wants copy Jim Alabacks article El Torbellino San Diego Orbiteers newsletter got started send SASE Craig Buchanan Bass Lake CA wrote regarding Testors Endurance Glider November column owned couple Testor s Endurance Gliders built under tutelage Bob Lawrence Chief Designer reporting Nils Testor 1947 think Bob actually did design late 1946 Bob taken few us teenagers under wing Saturday morning found us busy grinding away sanding blocks balsa out Testor factory located Rockfords east side came model building Bob wizard us began cutting corners own projects showed us no mercy square shooter generous fault am pleased have question answered liffle disappointed design cannot legal Society Antique Modelers SAM contender writer said Testors looks like generic 30s glider Bob Lawrence family could prove design pre-1942 Response offer ofThermic 18 20 plans surprise drive back copy shop three times nothing better old Thermic 18 20 young inexperienced clearly get idea some novices need basic instructions throwing adjusting design too much youngster teaching try 80% reduction plana certain minimum velocity needed get up make transition also surprised number people wanted plans Testors glider have decided make available $1 SASE number 10 envelope45 inches x 95 inches please people wanted share younger relatives neighbors simple joys years ago Testor designs younger relatives neighbors just wanted try HEGs first time found good article plan written Warren Kurth American Modeler July-August 1964 issue will supply reprints SASE $1 will throw couple surprise stocking stuffers relevant HLGs next column will reveal name person started using stabilizer tilt deliberately control glide circle person started Stay tuned keep cards letters coming need photos big problem photos receive cluttered background makes poor black-and-white reproduction Kits Plans Antiquitous KAPA quarterly newsletter people interested collecting old kits plans issue contains great articles history various models model companies Subscribers get advertise what seeking what have sell trade Cost $6 USA $11 via air mail Mexico Canada Send KAPA Morris E Leventhal 1788 Niobe Ave Anaheim CA 92804 h 1997 135 Floyd Caners test rig allowed him vary voltage ignition engine reverse coil polarity running Bill Bakers wife holds Testors Endurance Gliderwe now know model designed Bob Lawrence circa 1946