[KenWittlief]

The idea of having an arm that is moved by pneumatics, and locked in place anywhere within its range of motion - thats very clever! I dont think I have ever seen it done on a FIRST robot

you dont need to get fancy with the valves, simply use the flow restrictors to limit the speed at which the arm will move

and to get precise control, use feedback. Instead of having the operator release the clutch and move the arm up or down, and then engage the clutch at the right position, have something like a potentiometer on the arm reporting position. the operator would move the joystick up or down, and the system will sense the arm is not where the joystick says it should be, unlocks the clutch, pressurizes the cylinder in the right direction, and engages the clutch when the feedback sensor = the joystick setting.

I really like this idea. You could have a very light, very simple, multiple axis or multiple elbow articulated arm, with very precise control of its motion - using nothing but pnuematics!