Coaxial Piston Cannon

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TheLost
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Thu Apr 23, 2015 6:30 pm

Ok guys, Lost is at it again, but this time, with a coaxial piston design.

Here's what I'm thinking.

3'x3" chamber, with a 3'x2" barrel running down the center, with a coaxial piston at the back.

The valve to be used to open this coaxial piston will be a RainBird 1" sprinkler valve modified to pneumatic activation, via a standard compressor air gun.

The only question I have is an idea regarding faster followup shots from refilling the tank faster, though the projectile will still be muzzle loaded. The "faster follow up" comes from NOT having to connect the chamber to an air compressor after every shot. I had this crazy idea regarding 12/16g C02 cartridges that you all may find interesting. Basically, have six positioned radially around the chamber, and using them to refill the chamber by simply opening their valve into the chamber. I have guestimated that 3 12/16g tanks would be needed to fill the tank to ~50 psi, and 6 to get anywhere close to ~100psi.

So basically, the chamber could be filled via air compressor via ball valve with compressor QD, bike pump on a schraeder valve, or a couple 12/16g CO2 cartridges via Red Zeppelin fill ports.

What do you all think?

Worth it? Would it work? How many 12/16g tanks would I need to achieve certain pressures? (The chamber in in^3 is ~520in^3) Or am I insane?
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dart guy
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Thu Apr 23, 2015 8:31 pm

I think you created a very expensive air compressor.
when life gives you lemons... make root beer and leave the world wondering how you did that :D
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Gippeto
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Sat Apr 25, 2015 10:12 am

When you reduce the pressure of a gas, there is a cooling effect on that gas..(the greater the differential or speed, the greater the effect).which would be transferred to the pvc. Cold pvc and pressure is something which I suggest you avoid as plastics become increasingly brittle when cold.

Sounds like a reasonably well thought out piece...build it and enjoy it for what it is....without the co2.

Punching holes in stuff is fun....punching bloody BIG holes is SOoooo much MORE fun! 8)

That's my .02 at any rate....take it as you will. :)
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