F1D partial motor blast shield

From: Jake Palmer <82.jake_at_gmail.com>
Date: Mon, 16 Jul 2012 16:20:41 -0700

I had the fortune to spend some time talking to Larry Coslick at the Kibbie
Dome this year. I lost 2 motor tubes to motors that broke during or after
loading them onto the model (one broke just seconds after launch). He
mentioned something he's done in the past and I think it's a brilliant idea.

While he was doing partial motor testing he covered the first 4-5" of his
motor tube with a leftover piece of another motor tube. He cut open the
seam wide enough so it could slip over his motor tube, but narrow enough so
it stayed in place. The idea is that it's a semi-permanent blast shield
that stays on the plane during quarter and half motor testing. Even if the
motor breaks after launch it will protect the motor tube. It's about a
40-50mg weight penalty, although you can use a lighter partial motor stick
to offset the weight (just make sure you get your CG right). When he
switched to a full motor he removed the sleeve. I plan to use this idea
for all my future partial motor tests and I thought I'd share it with
anyone else that might find it useful.
Received on Mon Jul 16 2012 - 16:20:42 CEST