Ultimaker 2 - weird leveling issues?

[GiantWinter 0]

I just got a used Ultimaker 2 to replace my previous printer, and so far I haven't been able to get the printer up and running properly yet, and I'd like to ask around the community to see whether I'm doing something wrong, or are there steps that I'll need to do to get this printer going nicely.

 

First weird thing is this. I've leveled the plate as well as I could (using a piece of paper on both tries, since the printer didn't come with the leveling card), stopping at a point where there is a tiny bit of pressure on the paper. While the print was not perfect, I was able to get something like this out of the calibration test print:

 

 

Now, what is weird is that when I ran the print again immediately after the first print is done, using the same exact gcode from the SD card, I got this:

 

 

Seems like somehow the nozzle is now too close to the bed on all four corners, but the thing is I haven't even touched anything yet! As in the first image, I think the leveling is almost there, so my original intention was to manually micro-adjust the screws once the printer is printing, but as #2 happened... I'm not sure what to do now.

 

Could there be something wrong with the printer? Is my leveling process all wrong? Any other tips on leveling and calibration?

 

 

[gr5 1,399]

Almost certainly you are too *far* from the glass.  Just print again and as it prints the first layer push up on the bed a bit with your finger (or down).  If I'm right and the bed needs to go up closer to the nozzle just turn the 3 knobs CCW (as seen from below) about a half turn.  Turn all 3 knobs the same amount so that it stays *level* and such that you only adjust the height.

 

You will probably have to abort and start over but if you do this at the start of most prints you will get good at it.  Also once it's level it tends to stay level for months or until you change a nozzle.