I received my Glowforge a few months ago and set it up, but due to Life getting in the way, only started using it about a week or two ago.
I’ve noticed that the laser and the camera don’t seem to quite line up. After cutting a part, the red/cyan lines of the path don’t line up with where the laser actually cut. I noticed, but at first didn’t register this as a problem, until I was making a part that was only slightly smaller than the material. I positioned the image to be cut over the stock material, but when I cut, the laser went slightly off the edge of the material.
In an attempt to measure exactly what was happening, I cut (“scored”) a 1" by 1" L shape. I then reran the cut without touching or changing anything, and (as expected), the laser did a second pass exactly over the first. Next I zoomed in to 1000% on the image and lined up the cyan path with the line on the material, and ran a third pass. As predicted by past experience, this pass did not align. Specifically, the laser was 0.100 inches to the right (as viewed standing in front of the GF) and 0.053 inches closer to the hinge than would be expected based on the positioning in the UI.
For most projects, this would just be a minor annoyance, but if I were trying to align something to my material (such as etching the back of a phone, or cutting close to the edge), or (presumably) using the pass-through feature to create larger parts than the standard bed size, it becomes a serious problem.
I’ve searched the forums and found a few other people reporting similar problems. The recommended solutions seem to be (a) make sure you have the correct material height set, which I’ve done, and (b) perform the camera calibration step. I don’t recall having done this calibration when I initially setup my GF, and I don’t see any reference to it in the manual, the FAQ, or in the web UI. The forum posts just say to do it, but I haven’t seen any that explain how. What am I missing? How do I calibrate it so the image preview and the final laser cuts actually line up with each other?
UPDATE: It looks like this thread got closed, so all I can do is edit my post, rather than replying. First off, I think it’s bad policy to close a thread so quickly, without warning, and especially without the original poster being able to reopen it.
Secondly, I was able to perform the camera calibration process, and then rerun my “L” test. The calibration improved significantly. 0.053 inch offset in X was reduced to 0.030 inches, and 0.100 inch offset in Y was reduced to less than 0.010 inches.
I would recommend updating the user manual and/or the getting started guide to reference and link to the camera calibration. This seems like an important step for setting up a new machine, but there’s no obvious guidance for a new user how to do so, without knowing they need to search through the forums for instructions.