Microwave Oven Roller Wheel replacement
I have no idea how this thing will behave on long term on the microwave.
(I will tell you here if I got trouble in future).
This is a quick fix, and thanks to OpenSCAD you can adapt it to your need.
I use filament itself for the wheel axes.
I decline all responsibility if you use it in a working micro-wave oven!
(I can just tell I printed one in PLA and the part doesn't get warm when I heat up water)