Sunday, April 19, 2009

M750 payload section layup

I had purchased two 48" lengths of 98mm cardboard tubing for the M750 rocket below. However design stuff nags me in my sleep and lucid dreams so, instead, I purchased much stronger phenolic tubing from Public Missiles Ltd. just to be sure.  The added weight will probably cost me margin for the 20,000' goal but I eventually plan to fly it on much more punchy motors so... oh well.
Today I cut the payload tube to 26" and laid up three wraps of 5.6 oz. carbon fiber cloth with excess resin.  This time I mostly painted the epoxy on axially rather than radially so the fibers should be much straighter than my first two attempts.  I also applied two coats/buffs of carnauba wax to the Mylar™ film this time to lower its surface energy and mitigate/prevent stickage to the cured Aeropoxy.  My curing oven has been cooling down since about 1PM so I'm gonna pull the part soon (nice asymptotic cooling!).  I'm hoping that it's light, smooth, and devoid of voids.

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