Arm Mechanism Advice

[DonRotolo]

Originally Posted by Timothyw0

And lastly, our arm will need to stop in immediate locations.

I assume you meant to write "intermediate". If so, that's a deal-killer for pneumatics.

Why? Several reasons:
1. As the load on a pneumatic cylinder varies, its position changes. So that intermediate position will not be the same each time, as it depends on load (e.g., whether you have a ball or not)
2. Controlling air for intermediate positions is difficult. Not impossible, but difficult. There are dozens of threads on this from up to 8 years ago.
3. Pneumatic cylinders prefer either of 2 positions: Fully extended or fully retracted. For accurate end positions, you need to 'stack' cylinders, adding cost and complexity.

Bottom line: Be sure to TRY what you want to do before finalizing your design. You may find yourself agreeing with the above...