[sanddrag]

Originally Posted by ToMMan b182

to get the 6 points on the cylinder...

im guessing have 3 pnu lines going thru the robot, each with a different PSI. (maybe 40, 60, 80) Then you connect a solenoid to each one of those, and output all the A's to one side of the cylinder, and all the B's to the other. Then switching some on and off may do it.

Actually, i have no clue. but that may work.

anyone wana disprove it?

Don't have time to build a model ant test it but a pneumatic cylinder in theory (disregarding friction of course) should fully extend or retract no matter what the pressure (or the switching of a solenoid) because as long as there is a difference in pressure it will move all the way until the end of the cylinder stops it. Now, on these boards a lot we have talked about "multipositioning wit pneumatics" and I believe that is achieved using muliple solenoids and timing(or limit switch and program) them correctly to make sure both extend and retract ports are open (at equal pressure of course) when the cylinder reaches a certain position. That is just a guess as to how it works as I have not had time to actually read the multipositioning thread.

Now, it could be linearly actuated by some other means than pneumatics you know...