[ngreen]

We used the system all last year and still use it when we do different presentations and we have never changed either solenoid so I am pretty confident that there is no problem with backfeeding. Make sure there is no leaks to the system and if will work really pretty good. Like I said, we used a buttons that the actuator length changed as long as you held the button. We used a 8" stroke and slowed the speed of the actuator by only opening the valve to them only a quarter turn. By using programming you could open for increments of time (which means a specific distance) by pressing a button once. If I remember right the actuators may have a little more give than when not using it but it was not a problem for us. A note about the single solenoid: When not powered it returns to a not on side. Any questions please ask, or set a pneumatic board up on a piece of plywood with switches from Radioshack to control you solenoid to test. Pneumatics are very easy to implement and add and their are many resources avaliable from FIRST. I'm very excited about getting to use the rotary and magnetic piston actuators this year. If they don't use the rotary actuator on our robot I might convince them to order them for me the play with. I personally think they would work great for arms for the 30" ball.