Possible way to increase pneumatic cannon power?

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
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Mon May 20, 2019 9:36 pm

Hello everyone!

Recently I was thinking about this idea to increase your pneumatic cannon power if you are limited by pump source. I have no idea if this could work.

I have an ordinary bike pump which can go up to 6 bar and currently don't have an electrical air compressor. The idea is to create full metal ball valve Airgun, pressurize it to 6 bar and then heat it on the gas stove to a higher temperature. Spring loaded mechanism as a trigger would be used.

My reasoning is that gas expands as energy is added to a system. What are your thoughts on this?
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D_Hall
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Mon May 20, 2019 11:03 pm

Yes, heating it up would increase the theoretical performance of the gun. However, ball valves absolutely suck and the use of one would cripple you as compared to a normal pneumatic with a proper valve for the application.

Beyond that? It's a lot more energy efficient to just put the gas from the stove inside the gun, light it there, and call your gun a hybrid. That is, after all, how a hybrid works (more or less).
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Moonbogg
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Tue May 21, 2019 1:35 am

Sounds like you're on your way to a steam-powered spud gun? I have no idea how steam pressure works except that it makes things explode if a safety valve isn't used.
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jackssmirkingrevenge
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Tue May 21, 2019 4:44 am

just put the gas from the stove inside the gun, light it there, and call your gun a hybrid
Yup. You can also just buy one of those cheapo Chinese pumps and be done with it :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Tue May 21, 2019 6:43 pm

D_Hall wrote:Yes, heating it up would increase the theoretical performance of the gun. However, ball valves absolutely suck and the use of one would cripple you as compared to a normal pneumatic with a proper valve for the application.

Beyond that? It's a lot more energy efficient to just put the gas from the stove inside the gun, light it there, and call your gun a hybrid. That is, after all, how a hybrid works (more or less).
Then burst disc cannon would be a better solution. I am thinking bigger the chamber, more thermal energy can be stored.
Moonbogg wrote:Sounds like you're on your way to a steam-powered spud gun? I have no idea how steam pressure works except that it makes things explode if a safety valve isn't used.
It would perform better at rainy and humid days. The burst disc cannon would be a safety in itself, the thin aluminum disk would burst at a certain pressure. Perhaps adding a teaspoon of water plus pressurized air?
jackssmirkingrevenge wrote:
just put the gas from the stove inside the gun, light it there, and call your gun a hybrid
Yup. You can also just buy one of those cheapo Chinese pumps and be done with it :D

Or use Chinese high pressure pump and thermal energy :mrgreen:

Anyways, this is the chamber I plan to use. Everything would be isolated with aluminum foil and newspaper, except for the central part of the pipe which will be exposed to flames.

Image
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D_Hall
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Wed May 22, 2019 12:06 am

If you're just doing this to prove that it can be done, go for it.

DO understand that there are much easier ways to accomplish your goal, however.
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jackssmirkingrevenge
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Wed May 22, 2019 6:07 am

So the plan is to basically heat the chamber until the burst disk fails?

Sounds like fun :D make sure that the chamber material doesn't lose too much strength when being heated...
hectmarr wrote:You have to make many weapons, because this field is long and short life
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