Problems with artwork in illustrator not coming out to size on laser

[LightBurn (Oz)]

Most likely your machine isn’t calibrated correctly.

In the console, try this:
G0 X0 Y0 (press enter)
Mark the point where the laser head is.

Then type:
G0 X100 Y0 (press enter)
Mark the new point.

If they aren’t 100mm apart, your controller doesn’t know how big a mm is and needs to be calibrated in the firmware. These are the $100 and $101 settings in GRBL.

This post walks you through figuring out the proper values:

How are steps calibrated?

That’s fairly easy, though it depends on whether your controller uses “step size” or “steps per mm”. They’re used for the same thing, but the calculation is a little different. 80 steps per mm is 1/80mm per step. If you tell the machine to make a cut that is 100mm across, but it comes out to 150mm, your ratio is 150/100, or 1.5. You would divide your steps/mm by that number, or multiply your step length by that number, to get the correct answer. So, if your machine used 80 steps/mm, you woul…