Coaxial Piston Gun

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
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Marco321
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Hey
Here is my first piston gun I have ever made. I made absolutely everything I could on this gun. It is a coaxial gun, which is actuated by a barrel sealing piston valve, which is actuated by a custom made blowgun.

The piston is made from hot glue and the sealing face is made from bicycle inner tube

Now here is the gun. The blowgun trigger is not yet attached...
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Here is the piston in the coaxial valve
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Here is the piston and the squash ball bumper of the coaxial valve
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Here is the piston and pool noodle bumper of the barrel sealing piston valve which actuates the coaxial valve
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Here is the barrel sealing valve which actuates the coaxial valve
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Here is the lube I use
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I still need to attach the blowgun trigger to the gun, it can be seen in the pictures and is only connected through a hose, I need some suggestions on a location for the trigger.

A video and damage pictures will be made when I have attached the blowgun trigger to the gun.

Thanks
Marco
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jackssmirkingrevenge
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looks good though you could probably have actuated it with the blowgun directly if your pilot volume was small enough. Are you sure that the sube you're using doesn't attack the rubber? If I were you I'd use water-based lubes like KY Jelly, works just as well and is gentler on your seals ;)
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Marco321
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I was using a sprinkler valve, but i wanted the whole thing to be hand made and i thought, if i make the barrel sealer i can make it detachable, so if i feel the need i can put a chamber and barrel on it very easily. The barrel sealer is actuated by my blowgun, and thought i would scrape every bit of performance out of it, so i went ahead and made the barrel sealer to actuate the coaxial.

I checked the lube first, i was using cooking oil but it wasn't so good. On the back it says "...no silicon, acid or acid forming ingredients... will not harm metal points, surfaces, plastics, paints. enamels, or finishes, fiberglass, Formica or neoprene seals.." "Does not dry or wash of with water"
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experament-u2
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nice gun there Marco
im looking forward to it being together and painted
y not try what jack said, install the blow gun straight into the back of the valve? you might not be able to do it with ur home blowgun
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Marco321
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experament-u2 wrote:nice gun there Marco
im looking forward to it being together and painted
y not try what jack said, install the blow gun straight into the back of the valve? you might not be able to do it with ur home blowgun
Thanks for the kind words.

I might one day, but i figured why not do it, i wanted as much performance out of it as i could. I can do it with my homemade blowgun, it works for the barrel sealer which actuates the gun
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spud yeti
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Hey, the gun is looking good! I like the double piston actuation, good work on building a cannon thats a little different.
Good work :P
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potatoflinger
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That's awesome, I really like the homemade blowgun.
It's hard to soar with eagles when you're working with turkeys.
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Skywalker
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Looks good! What size of pipe do you have for the barrel and chamber?

I made a double-valve gun like that, the Negotiator 2. It was a real mess. I eventually tore it up for parts because I could never get the two pistons to both seat at the same time. And for the Neg 1, I had a home-made poppet-type valve for the trigger, but because I made it with a pretty large area, it was hard to open.
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Mitchza89
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Way to go, Shes finally up on spudfiles eh? Looks like everyone loves it. Well done again man, great job.
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Marco321
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Thanks for the kind words everyone :D

Skywalker just made me realize i didn't include any dimensions lol.

Well the chamber is 46mm OD, the barrel is 20mm OD
The valve setup is all made from the same size pipe and fittings, except for the barrel sealer valve which has a 25mm OD pipe as the barrel to let the air out.

I'm going to clean it up, put a stock on and mount the handle. Ill then post more pics of the gun, the damage pics and maybe a video.
Failure to plan is planning to fail.

The 7 P's - Proper Prior Preparation Prevents Piss Poor Performance
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