I printed the larger circles below last night. I turned the Glowforge off, lifted out the cut material, and left the rest of the sheet unmoved. This morning, I powered up and went back to add the smaller circles, and I notice that I no longer see the left edge of the circles.
I went ahead added and cut the small circles, and I see that the device thinks that it is printing to the right, and slightly up.
When the small circles were just cut, the lid was not opened after they were cut and nothing was moved or touched on the bed.
Camera alignment changes over time. The camera is attached to the lid, which you move every time you open/close it, and every time you do you shift it’s alignment slightly. The geometry of the wide-angle lens, and the mathematical processing required to “flatten” the image to remove the fish-eye effect means that even the slightest changes in the location of the camera can have a very large effect on the alignment at the edges of the image. It will tend to maintain better alignment directly under the camera where the geometry effects are minimal.
I have had my GF for a couple of years now and I long ago gave up on relying on the camera for anything but the grossest alignments. If I need to know exactly where something will be cut, I throw a bounding box around the object, tape a slice of cardboard to the crumb tray, cut out the box, place what I’m planning to cut inside the box, and then do my cut/engrave/whatever. This method guarantees my cuts are always perfectly aligned regardless of what the camera is telling me. If I’m not using this method, I never align things edge-to-edge, I always leave about 1/4" for “margin of error”.
No, you don’t need to calibrate and you would not get any improvement if you did. The camera alignment, according to Glowforge specs, is within 1/4". My camera alignment is quite precise, but others are not so lucky. What you experienced could be explained by where and how you used the set focus tool last night and today.
Hi @mahboud My name is Mercedes and I’m part of the Technical team here at Glowforge. It looks like the other members had some good advice to give you as well!
I was able to extract some logs and it looks like your Glowforge is performing to specifications. If you’d like, you can use the Camera Recalibrator to see if further improvement is possible. It will only make changes if it can make your camera more accurate; otherwise, it will exit without any changes. It takes about half an hour.
You’ll need a 12” x 20” piece of Proofgrade material with no markings or stickers. The feature was designed to be used with a flat piece of medium Proofgrade Draftboard, used upside-down (with the QR code side down). It may work with other materials that are the same size and use the same print settings as well, like Proofgrade plywood.
It prints a grid of markings, takes a picture, then measures its height in multiple locations. This data is used to make your camera more accurate for future prints.
