ABS tennis ball launcher with propane

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
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MrCrowley
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Thu Oct 04, 2007 11:55 pm

noname wrote:Wow. Apparently, you have no idea how unsafe this gun is. You solvent welded a PVC bushing into an ABS reducer. THis gun is also handheld. Could you possibly be dumber?

Also, reducing the diameter to 1" in the middle decreases performance like hell. A burst disc is also useless in a combustion, performance wise.
Wouldn't a burst disk increase performance if you had a less then optimum barrel length? Which would be a short barrel. If you managed to get the right materials for a weak burst disk which bursts around 40psi.

Because the projectile would be on the move in a normal combustion as soon as the mixture combusts (which wouldn't be peak pressure straight away) with a short barrel you would loose a fair bit of power, but if you had a burst disk which burst at the peak pressure of combustion the projectile wouldn't start moving until the combustion is already at it's peak pressure, which could make up for a slightly shorter barrel.
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BigGrib
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Fri Oct 05, 2007 12:05 am

Honestly i think that putting a burst dick on a combustion gun is pointless. I have tried a few of them and I dont get any better performance out of my gun with one. I think that a fixing the problem the correct way ,even if it is more expensive, would be the right thing to do. Especially with the way you got that abs-pvc gluing going on. One of these days that will fail and you'll be in a world of shit. spend the few extra bucks to fix it right, you'll be glad when it doesn't blow up in your face.

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spudgunnerwryyyyy
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Tue Oct 09, 2007 10:34 pm

OMG, without the burst disk i can see the paint balls come out of the barrel. With a piece of painters tape in the union paint balls like break in the barrel sometimes. Thats the difference.
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spudgunnerwryyyyy
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Tue Oct 09, 2007 10:38 pm

The pvc is EPOXIED on to the abs reducer. According to jsr and the epoxy package and my firm believe in epoxy. It is plenty strong enough.
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noname
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Wed Oct 10, 2007 6:05 pm

spudgunnerwryyyyy wrote:The pvc is EPOXIED on to the abs reducer. According to jsr and the epoxy package and my firm believe in epoxy. It is plenty strong enough.
You obviously should have specified, according to what silverdooty would say.
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