03-12-2016, 03:32 AM
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Master Modeler
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Join Date: Jan 2009
Location: Fairbanks, Alaska
Posts: 6,507
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Quote:
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Originally Posted by Rex R
not sure of the exact size...somewhere around 4500 cm^3 (this was a spud gun, the combustion chamber constructed from 3" pvc pipe), probably weighed in at around 10 pounds  . this said, he had a fair amount of room to work with(not to mention a far less hostile environment 0.05 seconds doesn't give the plastic time to warm much. we were running computer fans inside the chambers). piezo mics work on a change of state so they would only register an increase/decrease in pressure not an unchanging background pressure.
Rex |
Oops, sorry...I'd read "spud gun" in your other posting above, but in my haste to get caught up on neglected e-mails in between YORF postings, that didn't register. No, there wouldn't be too much heat transfer in such a gun. (I once made a PVC pipe cannon that used an empty styrofoam thread spool as a free "piston," above which the projectile [usually a lime or a sour orange] rode, and the styrofoam spool never showed any signs of melting after firings.) |