Here's an interesting engineering problem that has me stumped! Does anyone have suggestions? I recently got a 2 gallon vacuum chamber for resin casting and small experiments, and I would like to get a small and simple arm inside of the chamber to move things around while the vacuum is pulled. I have been considering methods of getting the arm to move but all of the ideas I've seen or come up with have had issues. So far I have seen or thought of the following: concept issue bowdin tube can't think of a way to seal it while being able to control it externally syringe based hydraulics/pneumatics (in pairs so they balance out when there's a pressure differential) seem like they'd be too big to fit with any space for a 'payload' to fit wireless electronics most batteries and motors/servos/controllers are not vacuum rated (rely on air cooling) magnetic coupling the chamber is ferrous metal with a very thick acrylic lid, so magnets won't penetrate well without more heavy…