Thread: ball cannon???
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Unread 06-01-2009, 14:20
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Re: ball cannon???

Quote:
Originally Posted by martin417 View Post
With a gap, F still = P x A, it is just much harder to get P very big. last year we were able to achieve a delta P of ~1 PSI, so with a 24" seal diameter, we had ~450 lb.s of force. With a 1/8" gap around a similar sized circle, you have a leak area of around 10 in^2 if you look at this as on orifice, it would equate to a diameter of ~3 1/2". if you can move enough air to get a pressure drop of 1/2 PSI, you have effectively added 225 lb.s to your bot. (not to mention the added benefit of the Bernoulli effect at the rim, very cool!)

You also now have 225 lbs of force trying to lift a .90" thick fiber panel from the floor. (have you ever seen an animation of "storm surge" in the eye of a hurricane?) I cannot imagine the rules committee allowing this.
Thanks for the calculation examples.
On a "storm surge", the ocean surface is fluid. The Regolith is a solid.
If there were an airsource under the regolith, it might be a problem.
If the a cardboard box lists 40psi bursting strength, I don't think Regolith will have a problem. I'm looking forward to this being asked in the Q&A though.
I'm pleased to see that nearly every cool idea of mine has already been discussed in detail here already.
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