Saturday, May 2, 2009

Machnum Force

My new 29mm machbuster is finally being built, and no I won't apologize for the pun. It uses a 13" length of standard 29mm tubing, which I'll reinforce with either wood glue or a paper wrap.

The nose cone is a 4.4" long balsa ogive that I bought at NARCON from BMS. I slathered 3 coats of wood glue on, letting dry in between, and it's now covered with a super-thin (maybe a half millimeter or less) coat of dried resin, clear and strong and smooth, and much easier to paint than plain balsa. Well worth the effort.

The fins are 1/8" ply, crappy but strong 3-ply stuff from an old non-flying heliocopter kit and a clementine box. The fins are fairly large, about 6.4" long and 1.8" wide in a trapezoid shape, with a long sweep on the leading edge and a slight forward sweep on the trailing edges. Two are fully cut and sanded; one is fully finished with 2 or 3 coats each of glue on the 2 sides and the edges; the other just needs its edges done.

I estimate around Mach 1.5 - 1800 fps / 1000 mph on a G78 or G80.

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