This is a very simple concept for creating a flat platform on a cylindrical rod. This was specifically designed as a means for supporting magnets across the axle of a simple home-made model AC generator (a cheap 5mm diameter stainless steel rod can fit through this prism snuggly due to the tolerant design of the central hole, especially when printed out of a flexible material at relatively low infill).

Prusa

I3 MK3S

Doesn't Matter

No

200

20%

The orientation of the print makes little difference, printing it on the largest flat faces suits this best.