[Joe G.]

We have had a shaft fail the snap ring and pull the shaft out of the carrier plate. We believe that the initial failure was user error on our part, with the snap ring not being fully seated, combined with a pretty signifigant tension load on the shaft pulling it outwards. This same kind of loading would likely be present on a versaplanetary direct driving a leadscrew. We found that once the failure happened once, it happened again to the same shaft a number of times, as the initial failure rounded out the snap ring groove. It's easier to do this on a versaplanetary than a solid shaft of the same size, due to the spline grooves.

We deepened the groove and used a slightly smaller snap ring as a stopgap measure, replaced the shaft entirely as soon as possible, and haven't seen it reoccur since. I imagine an e-clip would actually be more likely to strip out the groove, due to the smaller contact patch.

My guess is that your issue also can be tracked to an incorrectly installed snap ring, rather than an out of spec shaft. Properly specced snap ring grooves are much shallower than it seems like they should be, and they look even shallower when on a splined region as they are in the versaplanetary.