SpudFiles

Hers my 5 foot coaxial cannon. Its actually a little over 5 feet but I call it that because I made it from precut pvc that came in 5 foot lengths. Its a 2 inch chamber with a half inch barrel. Its got decent power and I can shoot a sharpened dowel through a piece of 1/4 in plywood at only 40psi. Its in my pile of guns that I need to paint so Ill post pictures as soon I paint it. Sorry about the quality of the pictures and I will post new ones as soon as I fix my camera.

Edit-This gun has been scrapped

wow thats massive!

I can shoot a sharpened dowel through a piece of 1/4 in plywood at only 40psi.

wow!!

I was surprised at the power too, I think it must be because of the massive chamber volume

That looks great, awesome power for 40 psi. I have always wanted to build a coax. It just seems like it won't work for some odd reason :[
What size tee is that? 1/2 I assume.

Yeah its 1/2 inch, I shot it at close range, if you want to build one go for it, if you build it right it should work, right now im having some piston problems with this one but it work great before I started rebuilding the piston

how fun is it rebuilding the whole thing when it's melted closed?

what do you mean, its serviceable

Ah I thought it was all PVC glued together. Oi, uber noob moment
have you made any other piston valve guns that are not coax? how do they compare to it?

http://www.spudfiles.com/forums/piston- ... 20112.html
Yeah I built this tee valve golfball gun, it shoots a larger round and probably shoots farther but I havent done testing, this one had better puncture but I prefer the golfball gun for the fact that it was easier to build, adjustible barrel, and porting size but its up to you, there both fun to build and shoot.

That's a great gun, changed my mind about needing high pressures in order to have a successful gun. Are there any guides or how-to's on a coax piston gun? I imagine it's not much different than a barrel or chamber sealing piston.

Do you have any suggestions on where to start? I'v seen the animation thread on piston valves, I understand how they work. I'm just skeptical about spending $50 on brass for it not to work. PVC should be much cheaper, right?

http://www.instructables.com/id/A-Coaxi ... ll-Cannon/
Yeah theres this one but dont use DWV or any other unpressure rated parts like this guy did
My suggestion is not to start with a mini, Id start with a 2 inch valve because there are many parts that make good pistons and are easy to adjust and theres lots of info. I used a 11/4 inch coupler for the piston

Thanks for that link. I read it but it's a little hard to understand what goes where. I'll just go out and buy some parts and figure it out.
Mind if I ask some questions if I need help? pleeeease

Feel free to ask me any questions, try a quick search before posting any questions but then its fine to post, you can PM me if you want too but im no master of piston valves like some other members on this site, the best way to find parts for a piston valve is to just see what fits good with what and just try it
http://www.instructables.com/id/Golfbal ... That-Shoo/
Heres a how-to for a 2inch one

I also had problems with my co-ax, rebuilt it three times, still didn't work, so I just used the sprinkler vavle for an inline.

I think I know how to fix it, I just need to get a couple parts, I think the problem was that the pistons sealing face wasnt level