ball cannon???

[martin417]

Originally Posted by Hachiban VIII

I believe the reason why 1771 was able to create so much force was becuase they had an excellent seal on the ball.

F = P x A

So if you can gradually build up pressure over a large area you can create a lot of force.

But without a seal on the floor, it'll be pretty darn near impossible to build up pressure.

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.