I am doing a logo on a stainless sleet painted water bottle. There are 3 layers that I am using. I use the same file/design on flat wood and all is perfect. As soon as I engrave the tumblers, they all go out of sync with each other.
If this happened to me, I would diagnose it as "Tumbler is slipping on the rollers. I say this because if it was a chuck rotary, I would see it slip off of the jaws.
1, Reduce your speed and the power to compensate.
2. You can reduce the acceleration ($121) parameter for the Yaxis, but will need to remember to set it back when done. Macros to the rescue here.
3.