Re: Pneumatics Resources
 

If your mid-cyllinder positioning does not have to be exact, you can use what Team 339 used in their offseason scrimmage bot -- a pilot-operated check valve. This valve came with the '01 or '02 KOP. It looked pretty tricky to hook all the tubes up to, but the good news is that you do not need a potentiometer or double solenoid valve -- the check valves mount directly to your cyllinders and use a single-solenoid valve that operates from a spike.

They work great and have fast enough response times for a driver to manually work the pneumatic cyllinder and stop in the middle of the cyllinder with enough accuracy. They do not work well in autonomous, so the piston would have to be all the way out or all the way in.

They work using air pressure -- essentially the two ports on the cyllinder are tubed/hooked up in such a way that air cannot go in one side without a change in air pressue from the other side. Since the spike can cut power to the solenoid at any time (therefore it will no longer change the pressure of the cyllinder subsystem after it) the cyllinder stops whenever the spike cuts power -- i.e. in the middle of the cyllinder.

It even sounds pretty cool to hear it in action -- it's like a slow-shooting paintball gun.