Okay so I have gotten the piston working. The problem was the frontal surface area :D I just put a smaller face for the neoprene to seal on and now the piston moves when I pilot it! I'll shrink the pilot volume when I get the money. Everything on this gun will screw on (Barrel, chamber and pilot) so ...

Now that makes sense. I can understand that air leaking around the piston before the pressure is reached would account for a drop in psi in the chamber. But depending on what that pressure was and how much volume and the size of the pilot valve and how fast the pilot valve actuated you could ...

Um no. Look at the math, I see that you say a lot about how pilot size is proportional to performance. Have you looked at the physics behind it? Give me some equations and some tests to prove your theory. Honestly I can see how it could go either way, but I've been lurking on this forum for like 3 ...

I'm only using duct tape on one place and I only got it up to pressures of 30 psi just to test, my dad is a aeronautic engineer and looked at it for a minute. He determined that the pilot volume hardly does anything for the gun's performance. (As stated previously) But I think that you are correct ...

Well I've seen how small the pilots were but i can't figure out why that would have so much of an effect... It's just some spare parts from my first pneumatic so don't worry I can replace it, but I wanted to see if it would work or not. Really though, why would pilot volume change anything? I want ...

The large side fits almost perfectly into a 1.25 tee and the small side fits with a seal into a 1" coupling. I also forgot to mention that the sealing face fits onto a one inch coupling and will seal at almost 1 psi. If that helps.

By the way the chamber has much more area than the pilot. The pilot ...

I know the pilot volume is rather large so you guys think that is the only thing? I assumed that pilot volume didn't have a whole lot to do with the piston not sucking back... But I can make the pilot volume a tad smaller... Lol.

Okay here are some pics, and again if someone could describe how easy it is to move their piston by hand it would be greatly appreciated.

http://i42.tinypic.com/2hxrek1.jpg

http://i39.tinypic.com/2du041s.jpg

http://i43.tinypic.com/28vrcqo.jpg

http://i39.tinypic.com/mlgwi8.jpg

http ...

I'm new here but I just am finishing my first gun with a piston valve. I made the valve from a lotion bottle filled with hot glue and with bike tire on one side. It fits into a 1 and 1/4 inch tee and then the back of my valve is a medication bottle that fits into a 1 inch coupling which is going ...