Saturday, February 7, 2009

Launch Report #18: Spiraling Pyrotechnics

I flew the Whirling Dervish twice today, both on A3-4Ts. It's a great motor for it, although it does eject on the ground. Both flights used my new 6V battery. It fires Estes igniters almost instantly; although slowly when cold. The first launch was around 3 pm after school. I had added a 6" or so extension to the wing. It flew about 20 feet up and 40 sideways, making a nice thop-thop-thop sound. It unfortunately alsi rebroke the launch pad. I have thoroughly reglued it, but I'll get an Estes E pad on an Aerotech Mantis pad sometime soon for a better replacement that can take MPR motors, particularly Es for flying a 29mm rocket at my main flying field.
For my second flight, I stuck a 4" length of 1/8" hollow aluminum rod into a chunk of 2x44 for the pad for a 2" usable rod; I put a 1" piece of plastic straw on to limit the rod to 1" and keep the monocopter from hitting the pad. I flew it around 6:30 at night; it was dark except for moonlight. I'd left the 6V lantern battery out in 10° weather for too long, so I had to bring it in to let it warm up first. It still ignited slowly because the cold battery didn't produce much amperage because the cold slowed down the chemical reaction. It was rather awesome in the dark; it rose to about 15 feet under power then fell back to earth. I'd never done a night launch before. Monocopters are good for flying in the dark as they're low, loud, firey, easily found, and would make for AWESOME pictures. The ejection on the ground was rather spectacular. I'm starting on an 18mm version now.
So far: 76 motors on 65 flights. 339.92 Ns, 6.23% I, total, equaling 4.47 (82.8% B) per motor and 5.23 (4.6% C) per flight.

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