01-14-2012, 02:45 PM
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BARCLONE Rocketry
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Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,357
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Mk VIII...
A little tweaking has given me a better stability margin, but a need for more power to make it work. The minimum power is now a D12-5, and it fully requires a 48" rod for launch. There is no room to spare, either.
RockSim does not give the true picture of how it should look; the centering ring at the front of the main skirt is rendered as going all the way down to the transition below it, and this is wrong. The ring's ID is only about 1/2" smaller than its OD.
The truss frame was modified with tabs at the forward end to attach into the ring. I need to stiffen the TE of the skirt with a ring, and some truss members to support it. Important, since this is what the model will be hitting when it lands.
One other change: The main skirt is now a gray-tinted "clear" polystyrene instead of cardstock. It's meant to be seen through.
Length: 19.75"
Diameter: 4.54" (Forward transition)
Shroud Span: 11.04"
Weight: 9.18 oz (With a D12-5)
Margin: 1.25......CG: 10.9603"......CP: 13.5119"
Funny alignment: The CP is located directly centered in the "combustion chamber" of the simulated engine.
D12-5......500'......Dv 16 FPS......Avg of 6 runs
More tweaking to come!
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