Originally Posted by
awerby
I doubt that a crash like that would disrupt your software settings. But it certainly could throw bolted-on rails out of alignment. If there are suddenly a few places where the motion of an axis isn't smooth, that's the first thing I'd check. Without applying power to the machine, just roll the stage along the rails and see if you can detect anyplace where it's hanging up. If it's not that, check the couplers for looseness. This may not be apparent at first, so make a mark with a Sharpie across the coupler and shaft, and see if you notice any offsetting when this "jumping" occurs. Set screws can get into a condition where they hold on seemingly tightly, but then come loose and move a little on the shaft when stressed. If it's not the rails or the couplers, then it's probably some other mechanical issue, like a distorted frame or damaged screw.