After building a Delta printer, I noticed that my whole prints are slightly tilted around the Z-axis in comparison to the slicer (e.g. Cura). There is no twist layer wise. This means, the prints themself look actually perfect.
I just don't know what could be the reason of the rotation. I do not believe it is a build issue of the printer, because I tried to keep the printer frame pretty stiff and symmetric. Could it be, that the Auto-Calibrate Feature of Marlin can add such a rotation?
The picture below illustrates the problem. I expect the black alignment of the print and get the orange one. Note that the print is still a rectangle with ~90° corners.