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Old 01-01-2007, 07:09 PM
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CPMcGraw CPMcGraw is offline
Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,357
Default Andromeda Update for 1-1-07

I just created a new simulation file of the Andromeda, with the addition of two CR-713 centering rings mounted at the openings of the shrouds. This will block off the flow of air through the shrouds and prevent them from acting as ringfins. The first indication that this may be important is the altitude gained: 910' versus 881' over the non-plugged non-ringfin simulation. The second indication that something changed was the stability margin; when using a C6-5 the margin dropped to 0.74. A ballast weight of 0.10 oz was added to the back of the nose cone, and the margin came back up to 1.13.

The fins were altered to allow the shrouds to fit better, and a slot was drawn in to allow for the two centering rings. A corresponding interlocking slot needs to be cut into both rings.

I'll work up the latest patterns and post them later tonight, or tomorrow.
Craig McGraw

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