SpudFiles

I just finished my first Pneumatic Tennis Ball Launcher. I implemented a barrel sealing piston with an over/under design. To actuate the piston I used an air blow gun. I pressurized it to 80psi and depressed the valve on the blow gun but the piston never moved, all the air escaped from the blowgun instead. The piston is free moving, I checked! Could the problem be I'm not releasing the pilot volume fast enough? Is that why modified irrigation valves are used? Any advice helpful.

What size tee is your piston housed in? If its 3" a blowgun usually won't pilot it unless you have an o-ring seal. Either make a better seal or get a bigger pilot valve.

It's a 2 inch tee with a 1/4 inch valve.

Try a larger flow, but I also suspect that a lot of blowguns are only intended to flow in one direction. Also if there are any restrictions such as the quick disconnect you could try removing them for more flow.

You'll probably need at least a 1/2" ball valve to pilot it, although you may be able to get away something smaller if your piston has o-rings.

You can pilot a 2" piston valve with a MODDED blowgun. But I'll admit, the construction has got to be very good.

O-rings on the piston are not necessary though.

This is how I did it on my first piston canon.

Even if you can pilot with a blowgun, I would not recommend it. There would be performance just a 1/2" ball valve away that you decide not to use because of an easier trigger system. And by performance, I mean easily noticeable performance.

If a 1/2" ball valve is too much of an annoyance for you, use a 3/4" or 1" modded sprinkler valve. Like I said before, even if you manage to pilot your piston with a very small pilot valve, congrats, but you are still wasting a lot of performance by doing so.

Well, a 1/2 ball valve is easy enough. I''ll try to pick one up this weekend. If it works out then my next mod will be the sprinkler valve. Thanks for the help.