My newest cannon fail... Any help out there?

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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jimmy101
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Thu Oct 01, 2009 2:29 pm

psycix wrote:The option between the packing peanuts and a fan would be a chamba-chain. A chain attached to the side of the chamber, shake the cannon and the chain will mix it. Makes sure you wont have to replace the peanuts every shot.

Chamber fan is highly recommended though.
Looking at his build a chamber chain or fan aren't applicable. The chamber is pretty small and there isn't a cleanout.

Packing peanuts are the only thing that makes sense. Airsoft pellets are too small to do much.

If static cling is a problem then either spray/wipe with a laundry antistatic agent or go much more ghetto and just dip it in water (oil, vaseline, paste, mustard, pickle juice ...). Stoping static build up isn't exactly rocket science, besides a bit more mass to the peanut would help.

If the gun is fired with the muzzle higher than the "breach" end then the peanut probably won't go anywhere. Point the gun up before firing to make sure the peanut is all the way back in the chamber.
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Boom_erang
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Fri Oct 30, 2009 5:52 pm

I think it is a lack of proper venting. The bottom of your chamber is sealed, right? You won't be able to get nearly enough fresh 02 in there that way.

After that, I think it is also a fairly small chamber and it will be difficult to get a good ratio of air to fuel. But until you can vent it, this won't matter.
jaythedogg
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Sun Nov 01, 2009 1:33 pm

I actually too the gun apart & moved the igniter, barrel & whatnot to a small coleman mini cooler/drink thermos.
Barrel out of the bottom, igniter attached to two 3 inch screws, in the side, tips within 2cm of each other.
The top is actually the base of the chamber, so it unscrews. I can vent & add a fan for mixing. Will post pics soon.
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Moonbogg
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Sun Nov 01, 2009 1:36 pm

Whats the pressure rating of a drink thermos I wonder? Looking forward to pics.
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pizlo
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Sun Nov 01, 2009 6:29 pm

why don't you just build a normal PVC with cleanout cap gun, with pvc cement?
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TwitchTheAussie
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Mon Nov 02, 2009 3:30 am

That would make a bit more sense wouldnt it? The skys the limit with a PVC Combustion :lol:
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Tue Nov 03, 2009 7:02 pm

Short answer, too easy. :)
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