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Old 01-18-2009, 01:17 AM
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Mark II Mark II is offline
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Join Date: Dec 2006
Location: Back Up in the Woods
Posts: 3,657

Hey, Jay! What do you say?

OK, here's my first dilemma. I whipped up a RockSim 8 clone of the Centuri Groove Tube #KA-11. Everything is done per the plans found at JimZ's site, and it is built with parts from Semroc. The result matches up pretty well with the rocket's vital statistics shown in the 1972 Centuri catalog at Ninfinger.

The recommended engines are A8-3, B4-4 and C6-5.

Here are my results:

Length: 18.35"
Diameter: 0.908" (ST-8)
Fin Span: 2.724"
Weight: 1.5 oz

All simulations use a 48" x 1/8" rod.

A8-3........79.6'......Dv 42.6 FPS
B4-4........99.2'......Dv 70.6 FPS
C6-5........105.6'.....Dv n/a

The rocket is unstable using all recommended engines.

What am I missing?

Mark \\.

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Mark S. Kulka NAR #86134 L1,_ASTRE #471_Adirondack Mountains, NY
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