Originally Posted by Ryan Dognaux
It's very possible though using elastic assistance via elastic tubing or rubber bands. Check out the DiscoBots robot from Gateway: https://vimeo.com/40536229
(Look ~0:40 seconds for the pneumatic cylinders raising and lowering their arm)
Our arm worked very well. We used two double action pistons, one on each arm. We used a massive amount of latex on each arm (20-35 feet??). The arm was tensioned so that it favored the middle of its range of motion.
If I did it again I would use >2 single action pistons to raise the arm up and 1 single regulated to a lower power + gravity to bring it down. This would conserve air.
In our case it was very important to keep the latex fresh.
Wasabi had a very cool multi stage pneumatic arm. Ours passively adapted between the medium and high goals.