@Manuel207 said in Printing ovals instead of circles:

@deckingman I tested a 400mm move and it is nearly perfect (maybe 0,2-0,3mm if even measurable?).

I also printed the same part with the second tool and voila perfect circles. So you are on the right path. It has probably something to do with the external driver. I am going to test different microstep settings and currents on the external driver? Do you have other suggestions what it could cause?

Well at least that's narrowed it down to the external driver. Sorry I have zero experience of external drivers so can't offer any other advice. Maybe someone more knowledgable than me about these things will step in.