i have a little offset in my k40, i tried tensioning the y belt (That was a little bit loose) but it didnt solve the whole issue.
The engraving and the cut is offseted by mm, is that a homing issue? or i need to find the right belt tension
why worry about a mm when you can just shift your work piece a mm to compensate.
it could also be the beam from the laser head is not 100% perpendicular to the motion plane.
Want to post pictures to make sure the problem is clear?