Working 12mm PVC here, contour path in from
the left toward the right. Several passes had through-cut and left less than 2mm. Before this last pass the 3mm ball nose end mill had not yet touched the waste board, so there’s a mark where it travelled. As a result you can clearly see this bug happen.
End mill comes in from the left, X axis freezes briefly, just before the turn, and then the rest of the contour, and the rest of this whole job is off by about 7mm to the west.
End mill made it out of the right edge with brute force but then the next cut in the job was more of a crash since the whole machine was now shifted leftwards by about 7mm.
What caused this stutter? There aren’t any physical obstacles here. The path of travel is clearly inside the machine’s bounds.
Could it be ESD? Maybe because these two sort of large chunks of PVC are being split apart, and this was the final moment of the final cut?