Yesterday before leaving work, I left a bunch of parts to print on our Prusa Mk4. This morning, I found all the parts with the same defect at the bottom: apparently the magnetic printing plate shifted ⅛¨ sideways on the bed 3 or 4 layers into the 7-hour print.
Unfortunately, I removed the magnetic plate without paying attention before I saw the defect, so I'm not really sure if this is what happened. It stands to reason, but it might also be both stepper motors somehow skipping at the same time. It seems unlikely, but maybe there has been a power brownout or something.
Or someone at the office interfered with the bed's movement at some point. But it seems unlikely too.
If the plate itself shifted, maybe it's because I had cleaned it with water just before and I may have left some slightly damp spots underneath, despite drying it as good as I could. I might also have failed to position the plate against the registration pins at the back of the bed, but I usually pay attention so that too is unlikely. Still, I might have been careless.
Has anybody had this sort of thing happen before? This is the first time for me.
I do have a camera but it doesn't record.
If it was a nozzle hit, it was a violent one: this was 8 separate parts printing on the same plate and all 8 parts were similarly shifted - meaning the plate itself had shifted underneath, or both motors skipped or lost their origins. So I don't think the nozzle hit anything.
The filament is PETG, but I don't think it matters. The prints don't lift off the bed because I use glue.
@ExtremeDullard sounds like it wasn’t a nozzle impact. Curious to hear if it happens again and you get to the bottom of it. I’ve found it can be tricky to diagnose 3d printing problems because unrelated issues can cause similar print artifacts. GL!
@ExtremeDullard although, if the nozzle was clipping/hitting the printed parts could that cause the motor to lose steps? Seems like that could have an effect on everything being printed.