Hi - the camera alignment is not the best to depend on. I had multiple runs where i would cancel the job to re-configure a task to a different power level or speed, without moving any artwork or the board set in the GF. I would then delete the lines that have been completed already, then hit print. The resulting print is offset by ~1 mm.
Help.
If you’re experiencing offset in back to back to back prints, you have something else going on that is causing the head to lose steps somewhere. Snapmarks, or registration marks, wouldn’t help that because it depends on knowing exactly where the head is.
I am simply doing one side right now. Back-to-back is a whole different beast that the GF hasn’t proven to me yet.
For my jobs, I have established a set focus height (ie. 0.25") and hit print on a multi-step print. I find that the registration of lines for the second half would not line up with my first half of the print, even with no changes to the orientation or position of any of the artwork or board in the GF.
I am experiencing such a difficult time registering alignments, trying to minimize wasted material and time due to poor registration solution. Definitely would like to give snapmarks a try to at least decrease reliance on manual user input.
The Powers That Be have said Snapmarks are on the back burner, at best.
Are they working on enhancements to registrations? I hope they are as this constraints the GF significantly on basic necessities for larger quantity production.
I wonder how the larger volume creators are coping with the lack of consistent registration. I’ve tried using jigs and the home-made crosshairs, but with nominal success rate. For one of my recent jobs where the client asked for 200 pieces of palm-sized cut artwork, set up was on average 2-5 minutes to ensure alignment between each run. That’s a significant amount of time spent on set up.
I hope to hear from staff if registration marks are being considered at all (i.e. backlog of these enhancements continue to be “wants” for the GF or “must-haves”?) and target timeline.
If you are doing the cut at the same time as the engrave, you can get 100% perfect alignment accuracy by doing the alignment in your design software before you print it.
Discussion on it below:
It should only get out of alignment if you are trying to use visual alignment to engrave on something that has already been cut out.
Also…have you run the Camera Calibration and do you use the Set Focus tool? Those will help with the visual alignment issues. 
Thanks Jules, will look into the Camera Calibration, and will look into the double sided engrave once I feel more confident with single-sided production. We’ve tried to tackle double sided engraves before but the results were haphazard and had a lot of waste (due to registration as well).
Yes, we’ve tried the Set Focus tool but even then, the registration still gets wonky.
For the latest iteration of issues, we had a multi-step set up. We would run the first half of the steps, confirm it visually looks good, then hit the ‘magic button’ to run the second half. The second half does not align to the first half even though the material did not move, the lid was not opened, and nothing on the UI was moved except for disabling first half of the steps & pressing ‘PRINT’. The artwork for the steps were basically intertwined with each other over the same area (ie. Set Focus would be in the same area) but the resulting finished product had elements misaligned from each other.
I do not see ‘repeatability’ nor ‘accuracy’ as a descriptor for our machine right now. I hope the Camera Calibration fixes that at minimum – thanks for the suggestion!
Tell them the time, date and time zone of the last misaligned print that you ran so they can find it in the logs. What you’re describing sounds like a software bug, and those take a long time to try to find and fix, but they do need to know about it as quickly as possible. I’ve seen one other person describe a similar situation so they might need to start trying to find it. Letting them know the time of the print will help.
Who do I contact/where?
Thank you for validating our experience. We were pulling our hair out because we tried following guides and tutorials but we couldn’t even get simple repeatability and sequential cuts.
If your artboard is 20" wide by 12" tall and you move nothing in the GFUI and do not move your material, the glowforge will lase in the same exact spot every time. Open the lid, don’t open the lid, turn the laser off and on again, it doesn’t matter it always places the laser in the same spot (assuming the laser head doesn’t bump into something or the drive belt slips or something else unlikely, but possible.) If this is not happening, you have a laser that needs to be fixed.
Note: The preview in the GFUI, at least on my machine, will ALWAYS be off on the second and subsequent runs. The GFUI will show that it is going to print somewhere else, but it never does it prints right where it should.
You can either just post the time here in the thread you opened, because that has created a ticket for you already, or if you already sent them a direct email you can respond to the auto-reply thread and update them with the information. (If you haven’t already contacted them by email, just put it here so they can find it in one place.)
The latest incident was around 12:30pm, EST today, right before opening this thread.
If they replay, they should see that the print stopped midway, then restarted but it shifted on the 2nd half.
Thanks Caribis, as per Jules’ linked guide, we’ll try the digital artboard method.
So far, as per another guide/tip, we had our items placed dead-center for maximum accuracy from the fish-eye camera. This hasn’t helped in the last few cuts. We had to keep 1/4-1/2" safeties around the outside to keep the artwork from running off the material. (material height is correct, Set Focus was in use).
If you need accuracy you need to use a jig. My machine has always had excellent placement, but I still use jigs when I need accuracy.
Okay, let me ask something here…from your description…did you have the Focus Height set independently for the two sections? (It’s possible to do that and I’ve sometimes done it if I want to get a different effect on an engrave…the machine will pause, the head will refocus, and printing will resume. That is what you are describing, but you have to set that independently.)
For the first half, no, Set Focus was not clicked, instead, the Focus Height was set on 0.25" on all sections (none was on auto focus)
On the second half, no, Set Focus was not clicked, all settings was same. We did delete some sections that were already scored so it didn’t over-score it, but one piece was kept to check for alignment (and it was already shifted from here onwards, appx 1mm)
Regarding your engrave scenario (it is very interesting), did you only set the first part to complete, then you manually reset the Focus Height to run the second part? Or is this something that can be accomplished in one run?
You can do it in one run as long as you use a different color for one batch over another. And by the way, that is what I would recommend doing in your situation to avoid the “Second Half Refocus”.
Make the first batch of text one color (Fill) and the second batch a different color. The one that you want to print first, leave with Black fill. The one you want to print second, fill with Green. If you want to do a third batch, fill it with Red.
That is going to set up 3 separate Engrave operations, they will print in that order, but the machine is not going to pause to refocus. It should stay at the same focus once you hit Print, and run the whole job.
That’s true. I understand the logic behind it now.
And yes, I actually have multi-coloured set up already, but I never thought to use it for multi-level engrave.
In a perfect world, it would be great to do everything in one run, but that’s not always the case. Unfortunately, I was expecting i can just continue from where I left off (ie. to caribis’s point, it should resume at the same area for the same objects) but that isn’t what’s happening right now.
I’ll try the Camera Calibration tonight 
Thank you very much @jules for the help! Once you’ve tried the Camera Recalibrator, could you let us know if you’re still running into trouble with your prints?
Not sure what you mean, but it never resumes or continues. It starts the whole job over from the beginning. But it does the job over in the same spots.