Hilariously bad alignment & shifting during print

The attached photos will probably tell a thousand words or so, but:

The circles cut first, starting at the ‘top left’. Clearly misaligned compared to the software preview.
The trapezoidal shapes cut second and are what can be described as correctly-aligned, considering the preview’s inaccuracy.
The top row of circles compresses towards the right of the bed. Starting with the second row, alignment between the two passes is correct.

Job was run around 3pm UK time, 21/09/18.

It looks to me as though the head or gantry bumped into something. I would say it was the holddown pin which was placed over the edge of the smooth part of the tray. This area of the tray must always be kept clear. You can see the pin that got bumped, on it’s side.

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I would have thought that, too, except supposedly it started cutting top-left first. And then magically re-aligned on the next row of shapes. Makes no sense to me.

I was next to the GF the entire time. No bumps. I laid that pin on its side as the retaining pin had to be right next to the raised plastic of the tray, so needed a spacer. Clearance is adequate.
If it had bumped into something, I would be impressed if this caused it to attain alignment when it started misaligned.

Well then I’m stumped too. Maybe they will see something interesting when they pull the logs.

Yeah, I’m hoping so. Confident that a reboot would avoid a repeat, but I figure bugs like this are always worth reporting.

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Ugh, that looks like the dreaded right-side misalignment issue that took out my first GF.

You could get ahead of the game by printing some Gifts of Good Measure in draftboard – do one in the middle of the bed, and then another one as far to the right as you can get it. If it’s what happened to mine, the one in the middle will be perfect, and the one on the right will get screwed up. (Things came out fine if I didn’t try to place anything in the right-most few inches of the bed.)

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I just tried another print. Bitmap centred on the bed and it started engraving far to the right and front… Time for that reboot I forgot to do…

I’m sorry your print didn’t come out as expected.

Can you please perform the following troubleshooting steps:

  • Reboot your Glowforge.
  • We included an extra piece of Proofgrade Draftboard with your materials shipment for troubleshooting. Please print the Gift of Good Measure on Proofgrade Draftboard on the far right side of the bed, as close to the edge as possible.
  • Let us know how it goes by including a photo of the print in your reply.

Seemed to work OK, though I did hear a bump during calibration. I cancelled the job and started the print again, this time watching it, and there was no bump.

Thanks for following up with the results of that test. I extracted the logs from your Glowforge to further investigate the print that didn’t turn out well. In that case, it looks like something might have moved the printer head of your Glowforge after calibration but before the start of the print. As a result, the print started from the wrong spot. Rebooting your Glowforge appears to have resolved the issue. If you run into any other trouble with alignment and rebooting does not help, please let us know. Thanks for letting us know about this!