I'll give an example, although I don't have pics (well, there may be some in the galleries on
www.d5robotics.com if you're lucky).
Last year, 1293 built this winch of an arm to handle the 2X ball. Overall, the design was...lacking. But the method seemed sound--we used a van door motor with a drum attached to it to winch this cable with green plastic coating on it (someone who knows, feel free to add the details) that went over a pulley and moved our arm up and down.
The van door motor still would do the job today...if we had the arm attached, that is.