pmalone wrote:thanks for all the help
how much of an advantage is there to using a piston valve over a sprinkler valve? and what is a good tutorial to follow to make one
Huge advantage. Once you get over 25mm in diameter(1") pistons start getting really effective and powerful.
For a 1.5" barrel i'd recommend a 2" piston valve. Though this is a tutorial I wrote and made, I still highly recommend you do a lot of research yourself so you know what you are doing, then you shouldn't have a problem follwing my tutorial as you'll understand most things,
If you don't understand it, you need to do more research.
Once you know enough, you should only really need to use my tutorial as a guide when you get stuck:
http://www.instructables.com/id/Golfbal ... That-Shoo/