[kz2zx]

We used 2-1/2" PVC pipe with a chain and paddle system to elevate balls and make them turn a 90' elbow at the top. We used a second similar system to index/advance non-magnet balls after we sorted them, to move them to our crate-feeding mechanism.

1 servo for each. Not inexpensive, because the sprockets are either expensive to buy from Tetrix, or expensive to mill (very high failure rate in production), and requires a lot of robot structure to take up slack in chain. Also, engineering the mounting system for the paddles to the chain is a pain and requires grinding sprockets, plus cutting relief holes for the paddles in the pipe. Took us a while, and I think we'll go for open transport systems next year if one's involved.