08-28-2011, 12:21 PM
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BARCLONE Rocketry
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Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,357
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Quote:
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Originally Posted by Carl@Semroc
We started refitting "Mabellette" to produce 10mm engines ... one small problem...
At between 3 and 5 seconds into the delay, the casing burns through on many of the engines ... It does not matter if the delay is a fast burning (10sec/inch) or slow burning (30sec/inch) type. It is still around 5-7 seconds of total time since ignition. Replacing the delay with BP gives a 2+ second burn with no case weakness...
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Sounds like the delay grain burns a bit hotter than the propellant grain. If replacing the delay with BP doesn't cause a burn-through, then it must be a temperature issue. Are there any delay grains that burn at a lower temperature? |