Hi Jedrzej, welcome to the forum 🙂

- Check machine specification. You haven't said what kind of machine you have, so I can't really say if your numbers look right or not.
- Upload machine spec. Make sure the spec is uploaded to the machine itself.

The width of the square, drawn looks about right if that is an A4 piece of paper (is it?). The height looks off by about 20%. Its normal for the lines to be curved unless you are using "draw direct" to move the pen around, but they should reach the correct point eventually of course.

The pen width tests look a bit odd, like there was too much pen sticking out of the gondola, and it was swinging around the tip. Only you can tell whether that is happening by watching it while it does it. Ideally every movement of the string should result in a line being marked on the page. If a movement of the string results in the gondola tilting, or the pen tip staying in the same place, you need to do some adjustment. Again, without seeing your pen holder setup, difficult to say.

Even saying that though, they still look a bit weird. Maybe try with a larger grid, it might be clearer what's happening.

sn