My 3d printer appears to have taken up a drinking habit

[GeoffMAOT]

Hi all, I have a Ender 3 Pro.

I've put several spools of filament through it with no issues. Lately, it's been having some issues.

I printed a wheel, and it was probably 80% done before it seemed to forget what it was doing. Bottom half, perfect. Top half, slanted like a drunken sailor.
I then printed a large print that was also circular. It printed the first 2mm, then shifted somewhat and printed the rest of the model (4+ inches) 2 mm to the right.
After that I noticed quite a bit of buildup around the nozzle, and above the nozzle (around the heatsink). Took it all apart and cleaned it.
Started another print of the wheel, and this time the print was even worse.

Images are attached.
First iteration named 1st pt1 and pt2. Second named 2nd pt1 and pt2.

Both are the same model. Same filament (Overture PETG). Bed 84C. Nozzle 240C. Platform: Raft

First iteration:
layer height .2
Shell 1.2
Infill 40%

Second iteration:
layer height .06
Shell .8
Infill 40%

[Davo]

That's layer shift, and there are two options:

1. The print didn't stick to the bed well, and while the newer layers were placed properly, the model on which they were placed was not where it should have been.

But this is most likely the second:

2. The head got momentarily hung, probably on part of the model, and so the head was not where the printer thought it was, and material was deposited in the wrong X/Y position from there upward; the same issue may have caused subsequent moves.I'm guessing there's no closed-loop feedback, so no detection of missed steps - correct?All you can do is watch the print and try and determine at which point the head gets hung on the model. It's possible that thicker layers and/or more cooling can fix this. See also:

https://www.simplify3d.com/support/p...ayer-shifting/

https://reprap.org/wiki/Shifted_layers

https://rigid.ink/pages/ultimate-tro...gned-layers-19

[curious aardvark]

also check the belts are tight and none of the pulleys are slipping.
That will also cause the same issues.

I mean it's an ender 3 - so you know, expect problems :-)