SpudFiles

Yeah you mean like cut it with a piece of 1 1/4 inch pipe inside the coupling?

Also how does a sanding drum work as a piston. And do I have to remove the sand paper from it? Sorry I'm kind of new to this

Yes and the o ring will be placed on the pipe with the coupling on either side of it. With the sanding drum ya u take the paper off and put a washer the same size on both ends with a bolt and nut and sealing face. You adjust it by tightening it till it slides perfectly. Dont forget to lube it.

What do you guys think of the new one.(Bottom picture)

Uhhh why is it like a foot long??

Its actually only 7 inches should i shorten it?

Damn that thing is huge!!! But, if it works, then it works. How big is you housing???

2inch t and some 2 inch pipe behind it. And it's going to have a 1inch pilot.

Also what size chamber would you recommend.

8tonsemi wrote:Also what size chamber would you recommend.

http://www.thehalls-in-bfe.com/GGDT/

Chamber and barrel should be to your likings, with a two inch tee as a housing I would use a 2 inch chamber prolly 4 to 5 feet long but thats me. If your making this from gun freaks tutorial look at his golf ball cannon or Mr. C's.

Sorry for the bump I just didn't want to start a new topic. This is my new piston its made out of a frisbee that I cut with a hole saw. I need to get a sealing face and another o-ring and this thing will be set.

I dont think its going to work. I think the plastic will cave once you hit it with pressure. You also need a washer to hold on the sealing face. Maybe it will though, keep your fingers crossed....

Thanks Matty. I got a heat gun yesterday so I going to make out of sheet pvc instead

Save yourself the time and bullshit and just get a rubber sanding drum. Unless you have a lathe its the best piston your going to get...