Need better pilot

[turbohacker]

I am finilly building an all metal pnumatic T shirt gun. What you see here is as far as I have gotten. (I dont have very much spare time lately)

I need an idea for a pilot valve that is much shorter than the modified sprinkler valve that I am using. It must be electronicly fired, (because the gun will have a keyed safty)less than two inches long, and it has to flow enough to empty the center of that welded pipe seen in the fourth Photo.

Also any sugestions for the overall gun are also welcome. I am planning on selling it for $350-$500 dollars.

P.S. Its a Coaxail diaphram cannon if you didnt notice.

[frankrede]

Why does it have to be shorter?

You could have the valve run parallel to the chamber using some elbows.

[iPaintball]

What kind of pilot do you have? That doesn't look like a sprinkler valve...

[turbohacker]

I need a shorter one because I would like to shorten the overall lenth of the gun, yet keep it as one simple tube (no elbows) for a proffesonal look.

@iPaintball, it is a sprinkler valve, I just cut off that back flow prevernter thingy.

[iPaintball]

Oh, i get it. Do those types of sprinkler valves use pistons?

[frankrede]

It probably uses a diaphragm, I have seen some with pistons though.

[turbohacker]

This one uses a piston, It opens quite fast accually.

Any ideas at all about the pilot?

[pyrogeek]

What about using the solenoid alone, and using that to pilot a small homemade piston valve to pilot the other piston valve? Or since the solenoid has a metal rod inside it that gets pushed in one direction when the current is applied, maybe you could stick a rod in there, and have that rod press on a modified blow gun?
Otherwise, there is always the option of a mechanical trigger, and then have the solenoid modified so the rod inside will either block the trigger from being able to move, or let it move freely.

[turbohacker]

There are two probloms with that idea. One, when the current is applied the rod is sucked in, not pushed out. And Second, I would like the gun to be electronicly fired because it has to have a keyed safety.