The honeymoon is over - extrusion problems

My new U1 has been printing so great. I just printed a plate full of bag tags. One came off the plate during the last layer, the rest look like this on the back. I can’t ship them. I used generic PLA and didn’t change any filament settings. The rippling was so severe that they were barely stuck to the plate. I understand this to be overextrusion.

Edit: I ran the bed leveler and started a print with just one object. First 3 layers so far are perfect. Could that really be it?

Why not? Your description is a classic symptom of z offset miscalibrated.

Wow. I never got in the habit of running it every print but I will from now on.

It shouldn’t need doing every time, but when the alternative is an occasional failed print, it is probably worth it.

I personally like to run adaptive mesh, this way it only probes the area where you print on. This saves time and usually gives a great resolution mesh, in my experience better than doing a full bed mesh.

That’s done with G Code?