[EricH]

Originally Posted by cmwilson13

u cant stop them mid stroke they will always extende if u put pressure to both sides ther is more surfuce area to extend then retract the rod blocks some of the retraction area
http://docs.engineeringtoolbox.com/d...c-cylinder.png
if u look at that picture u can see why there is less surfuce area to retract

You can stop them mid-stroke. It's been done. It's been done in FRC.

If you put the same pressure on both sides, the piston may move...

...Provided that the displaced air has somewhere to go. If that air has nowhere to go, then the piston's motion will stop as soon as the force on each side is equal. Motion will resume as soon as the air has somewhere to go again. By placing a single solenoid on the exhaust of a double solenoid, it is perfectly possible to gain control over where the piston stops.