Quote:
Originally Posted by Jared
Worm drives CAN backdrive- especially multi start worms. As they wear in, they can backdrive a vibrating and shaking robot.
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This is certainly true.
As a note, if anyone is looking at the AM WormBox, we used it last year as the initial (and largest) reduction for the arm on our
2014 robot, Kaizen. The WormBox has a multi-start worm gear and was very much back-drivable by the 'reaction forces' of our robot accelerating and stopping. We counter-balanced this arm reasonably well using surgical tubing to enable us to gear the arm faster... with this counter-balance the arm wouldn't backdrive the WormBox when sitting statically (at least when not holding a ball), but could be backdriven if you pushed the arm to a desired position.
The WormBox worked pretty well for us (enabling us to have compact, lightweight, low-backlash gearing), but we did preemptively insert one or two thrust bearings axially on the worm-shaft, which I would recommend to anyone that uses it, particularly if they expect impact loading on the mechanism. We only got away with cantilevering the output gear for a while before we wore down the 7075 Aluminum gear that we mated to it and the press fit of a bearing on the output shaft of the WormBox. This was in issue with our implementation though, not the WormBox.