SpudFiles

I was thinking of putting styrophome or something soft to stop the piston.

I don't know where to get and o-ring that size and how would you hold it in place anyway? Is it a lot simpler? I am still getting the parts together to make this and could use that instead...

But also instead of nitrile rubber could I use the thick latex kitchen gloves on the hard rubber?

Thanks for all the help BTW!

I have most of the parts now but I am re-thinking the exhaust hose.
I have pressurized hose from Lowes and was going to just thread it into the back and wrap it around to sit on top of the cannon. Instead I am going to use 2 90 degree elbow pieces.

Also I am not sure about a valve I bought on ebay. Its a cheap ball valve that is 1/4" threaded female and supposedly 3/8" hose male part on the other side. It is not a tight fit into the hose though... should I not use it or just put some plumbers tape around it and use a metal clamp?

Your hose probably isn't the right size... It should be pretty tight on the barb.

Look at the showcase for piston ideas and inspiration.

Use a rubber sanding drum for a piston, I have had good luck with them