Brief Power Outage Mid-print

OK final results: set focus tool no change at all. Zoomed to 300 and tried manually realigning it. No surprise, that did not work either.

So I decided to take the leather out of the laser and hand cut it. To my surprise, all but 2 of the links came out with a little bit of persuasion. Must have been the two links I tried to remove after the first cut.

Soooo back to putting links together. If you thought the wooden chain was sexy, wait until you see the finished product!

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EXCELLENT the glowforge gods are smiling on you!

:stuck_out_tongue:

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Oh, sorry. I misunderstood. I thought you hadn’t yet run it the second time. But, even so…sounds like it didn’t work anyway. What a bummer!

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I just wonder if the head didn’t get bumped somehow to cause that much misalignment. Sometimes I’m pretty sure I didn’t touch the head but turns out I did.

Depending on what it was doing when the power went out, it COULD have “coasted” a bit. Alignment after a power failure is going to be iffy no matter what.

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I did not open the lid.

I have had a lot of success with doing a engrave, and then going back and doing a score over the engrave, But I will say I may be a kerf off, eyeballing it gets you so close…

Not opening the lid was your problem. The head was moving when the power went out so it didn’t count some of the steps the stepper motors took due to momentum. Opening the lid would have caused the machine to recenter which would have gotten the steps back to relate it to a known location. Then you would have been able to re-run without moving anything and it would have been right on.

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Thanks. I’ll try to remember that when I have another power failure.

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what @wilsonpf says makes sense, when you are doing a 2 sided burn, you open the cover to flip the material, and then do the next burn without adjusting anything.

I think this is incorrect.

The glowforge power cycled, it would have recentered.

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I’ve had power outages where the power was off so briefly that the print stopped but the lights and fan on the GF only flickered - I did not have to turn the GF back on so it did not recenter. Then I have had power outages where it went out completely and did not start back up - those I had to turn the machine on and it recentered. I get power issues at my house at least once a week - just came back on after a 3 day outage :frowning_face:

So whats the feasibility of a UPS on a glow forge?
I would hate to lose power 3 hrs into a 5 hr print…

@evansd2 ?

Any half-decent UPS works just fine. It’s just a small computer with some moderate power requirements. No different than an average 3D printer. Been a while since I checked but I think peak power is around 800W. Edit - I just checked the monitor I have mine plugged into, it says peak was 436W. It’s been a few months since I’ve lost power so that’s probably accurate.

GF won’t support it, however.

That is complete nonsense, and not how the machine operates at all.

The machine “re-centers” (they call it “re-calibrate”) every time it reboots, which happens any time power is interrupted, or an update is applied (that can happen after a print, if the download had not completed when a print was started.)

You can (with power removed) move the head just about anywhere in the print area, and the machine will “re-calibrate” to within a fraction of a mm, every time. It uses the lid camera to determine the approximate location, then moves the head from there to directly underneath that camera until it considers it “centered”.

Chances are good that the power outage messed with the location settings. With everything working a second cutting should cut in exactly the same place. I have forgotten to reset the set focus and it cut in exactly the right place even though the automatic set focus grabbed the wrong place, and where it said it would cut was well away from the previous cut but it reversed the error anyway and cut properly.

A much more difficult case would be when the piece had moved or I could not use exactly the same location. A number of times now I have been trying to cut 1/4’ mahogany and no matter how many passes it would flame enough to not allow full cutting even as it left a mark on some of the other side.

So I have flipped both pattern and material and as at all times keeping the rotation horizontal (as that is the biggest source of error), I have used both set focus and very close visual alignment to align the design to those locations on the other side that showed through. If still concerned I can run the cut as a very light score to see if it is actually off and then use the score so the apparent cut is the same distance on the other side of the desired cut and narrow the error even more.

If as you point out the outer reaches of the design are off, then do your alignment towards the center under the camera if you can. the Error on the edges will still be off by the same amount and make up the difference :grin:

I have not found a way to correct for rotation so using 4x4 or 2x6 tiles at the bottom resting against the forward door to be my best proof against problems there.

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It looks like a few folks figured it out, but yes, when it lost power the head lost where it was. If you rebooted and/or hit refresh and then hit go without realigning anything it should be good - but just hitting go ahead made it think it was X spot when it was actually at X-2.

Yay for the links coming out clean!

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