Art1Top did not print without a fight. The job was an 8h30 3D print job because it had a lot of support structures that on my Prussa tends to start warping and ends up with a failed print 6 hours into the print.

Art1Top is the upper part that rotates the base. It is screwed down with3 bolts to the lower cog.

I had to print the rest of it in a second trial and then glue the 2 parts together.

First glance when I assemble it, it rotates normally and without offset.

Fully assembled rotation plateau. Upside down on this image to show the inner cog that drives the upper base. And the 3 nuts that squeezes the upper part to the ball bearing inner ring. The plastic wall with the split is intended for a homing photo detector, but in this 3D print it also came lose. Again the gluing method was required.

Maybe that part could have some slope to prevent this from breaking off.

Showing the ball bearing where the outer side gets fixed to the base. Art1Top is then positioned to the inner side and 3 screws will pull up the lower cog and squeeze both parts into the inner ring. Free to rotate the base.

Art1Top now assembled on top of the ball bearing.

We have a big opening in the middle for wiring and 4 nut holders to screw on the upper part.

This assembly goes onto the base.

Fully assembled base. The 3 big holes are places for the 3 stepper motors. That part must be reprinted because I can't squeeze the motors in. It appears that the 3D plastic is off with or 1 or 2 mm.

Yes the upper part has also issue with broken off plastic. The walls are maybe too thin.