[emo Sponge]

Originally Posted by rocketperson44

Yes, but it would be just as dangerous if it was motor powered. Anyways, either way, proper precautions to limit the risk of injury should be taken.



Back to the arm, it sounds like you are not completely sure over whether it needs more than 2 positions. In this case, motors would probably be advantageous. If you are not sure, than that (correct me if I'm wrong) means that you are probably not sure what the third position would be. As others have said, using sensors/mechanical stops/multiple cylinders, it is definatly possible to have 3 or more pneumatic positions. However, it is much harder to make these positions variable. Motors will allow you to put the arm in any positon needed, with no tricky mechanical work.

If you are sure, then the simplest way to do it would probably be what EricH suggested:

http://www.putfile.com/pic.php?img=7596589

your totaly right about the precautions