SpudFiles

If it destroyed the racket ball it will definatly destroy the tennis ball,try a large spring, and Mark its about 2 inches opened, pilots large about, 3-4 inches without the bumper, It will dramatically decrease once I get my new bushing and add the bumper, it needed to be shortened because its flow was only an 1 inch flow space

I don't think so, the raquet ball was old and crinkley and tennis balls are more squishy so I'll try one.

Well if it was old and rotten, try a bouncy ball, one of those that cost .75 cents from a machine

Those are solid though, it would be a terrible bumper.

no, the ones im thinking of are softer

oh... well tomorrow i'll try the tennis ball.

Actually, Gun Freak, I've made a couple of valves last year which had a bumper that was simply 1/4" of flat silicone rubber (the red stuff used for plumbing). Of course, I've only used those valves a handful of times, so I have no guarantees as to the longevity of such a setup, so you use that idea at your own risk...

I don't want to take any risks, I can't rebuild this valve. I'm using a massive bumper (lol) or not firing it.

I've had very good luck with the inside of a Nerf Football. My 2 inch ABS test cannon is still using the original bumper. To reduce damage the piston stroke is long with a long bumper for safe deceleration of the piston. This foam has never had any problem being blown out the hole. The foam bumper has a hole through it (for the rope) about 1/2 inch in diameter. It is made in 2 sections glued to a washer in the middle to help keep it aligned.

You can see it on the end cap next to the golf ball. It gets regular use at 65-75 PSI. This is a 2 inch cannon. When the valve is closed, it sits about 1.5 inches from the bumber.

Id use foam but it keeps getting sucked into the pilot valve
Edit-I found a great bumper, I put foam on the back of the piston and a tennis ball on adapter

Sweet, when I reassemble my gun today I'll try a tennis ball.

Id also ad a piece of foam to the back of your piston, It seems to help a lot

I did not add foam to my piston. I works fine. If foam is getting blown out of the pilot valve, the air path is too obstructed. Make a hole in the center of the bumper for an airflow path for the pilot air to vent through. All my piston valve cannons have a hole through the bumper. I have no issues with them blowing out.

clemsonguy1125 wrote:Id also ad a piece of foam to the back of your piston, It seems to help a lot

I was going to do that, but it would only add weight to the piston (not much though) and I already had enough foam. Maybe I'll try it next time it's getting serviced.

I used a pool noodle