[pras870]

To clarify, you cannot use an off the shelf vacuum. My team comtimplated this last year, and found that it was in fact illegal. Instead, we bought a festo suction cup, which created suction through a vacuum. Now I know this contradicts what I said, but it was not in fact a vacuum. We simply used 2 of the largest cylinders we could get (I think it was a 2" bore?), we used 1 to raise our arm, and the other cylinder was right next to it, with it's output valve connected to the cup. So simply, when you move the arm down, it created a vacuum/suction in the cup. However, you cannot keep constant pressure like this, so you basically had to keep pumping the arm up and down to keep the suction. I'm assuming you want to create some sort of vacuum to grip onto the big ball, and without using an actual vacuum, this simply isn't possible.