They say time is relative – and my Bambu H2D seems to prove it by running in a completely different timeline!
While I’ve already read a few posts about print jobs taking significantly longer than estimated, I haven’t really seen anything about laser engraving times being off – and that’s exactly what I’ve been experiencing.
Here are two examples from a single job (laser engraving coasters):
Screenshot 1: At 20:49 my PC clock shows the job at 5% progress. The H2D claims “Processed 2 min / Remaining time 40 min”.
Screenshot 2: At 21:49 (a full hour later), the progress is only at 59%. The printer now says “Processed 25 min / Remaining time 17 min”.
So while the machine thinks it has only been working for 25 minutes, in real life 60 minutes have passed.
This doesn’t happen every time, but I’ve seen it quite a few times now. It seems that laser jobs often take much longer than both the slicer estimate and the printer’s live calculation.
Has anyone else seen this with the H2D laser module?
Is this a known bug, or just another proof that my Bambu exists in a parallel universe?
I would call your phenomenon the “Microsoft minutes”. That is the behavior you see when copying files in Windows. There the estimated time varies just as much.
But let’s get serious.
Is your laser running in (1) scanning mode or (2) does is follow contours of the image?
For the (1) mode I mean it’s moving in straight horizontal lines and offsets a tiny bit each pass.
For number (2) I can imagine that there is no compensation for acceleration. So if it might simply divide tool path length by speed, and you get a theoretical time that eventually cannot be met due to numerous speed variations.
In this case Bambu Suite should borrow some math from Bambu Studio to get better time estimates.
I have been engraving stainless steel coasters in mode 1 and times were pretty accurate.
Have done some work in mode 2 also, but that was mainly text with times below a minute, and didn’t really bother to time those, so can’t confirm or deny your issue.
It’s not super obvious in the photos, but if you look closely you can see I was engraving grayscale on the coasters - so this must have been scanning mode.
And yes, I’ve also engraved coasters without this issue; it doesn’t happen every time, only occasionally.
This is the first time I actually tracked it and took screenshots. Previously, when jobs ran longer than expected, I assumed my own sense of time was off.
I trusted the H2D display.
Now I’m fairly sure it wasn’t me: the H2D seems to be running slower than it should. My working theory is that the controller/CPU is throttled or under-running, which would throw off its timing and make the motion control lag. It’s the only explanation that currently fits what I’m seeing.
