does this piston look right.

[8tonsemi]

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

[8tonsemi]

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

[mattyzip77]

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.

[8tonsemi]

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

[Gun Freak]

Uhhh why is it like a foot long??

[8tonsemi]

Its actually only 7 inches should i shorten it?

[mattyzip77]

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

[8tonsemi]

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

[8tonsemi]

Also what size chamber would you recommend.

[MrCrowley]

Also what size chamber would you recommend.

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

[mattyzip77]

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.

[8tonsemi]

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.

[mattyzip77]

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....

[8tonsemi]

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

[mattyzip77]

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...