Question - Cut placement accuracy (does the head align itself optically and why?)

I recently cut a design 3 times in the same material. Each cut took 30 seconds and I did them all back-to-back. I never touched the material or opened the lid, yet the cut lines are not consistent. There is at least 0.5mm of variance between the 3 cuts and it is clearly visible to the eye.

Is the GF trying to align itself optically instead of using data from the stepper motors? The motors are VERY precise. But, there seems to be an accuracy issue in determining where the cut begins (where the design falls on the bed).

If the motor coords are set to zero in its resting position, and my cut starts at some X,Y position, shouldn’t the cut start there every time? I feel like noise from the camera is affecting the image and the GF is trying to interpret where my design falls, even though it was never changed.

My material was black, which I think may have led to poor focus. But, I don’t think material should have any effect on the cut precision and accuracy.

I’ve also observed that the bed image is cropped. If I place my material to the far left, the far left edge appears on the left of the bed image. If I move the material over to the right, the bed image adjusts and instead of seeing the gap on the left edge, the image is cropped and I see only the left edge of my material. This seems to do more harm than good and results in me “chasing” the left most cutting position. Why crop the bed image?

Has anyone else come across similar issues?

The subsequent cuts should be indistinguishable from the original. The camera is used to optically align to the Glowforge logo on top of the head, on initial boot-up but not after that.


A picture is worth 1000 words. Can you show us something? :sunglasses:

If the material and image are not moved at all, just pressing print again, there should be no difference where the laser hits each time. Support will definitely want to look into it. Time and pictures may help.

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I’m so sorry your prints didn’t come out as you expected.

Can you take some photos of the issue you’re seeing?

If you’d prefer not to share them here, you can email them directly to us at

It’s been a little while since I’ve seen any replies on this thread so I’m going to close it. If you still need help with this please either start a new thread or email