A steinmitz solid is a intersection of 2 cylinders.
steinmitz solids have some interesting properties, they can roll along only 2 axes.
amazon basics pla
There is one file for the whole thing, it does not need glue or assembly.
The other files need to be mirrored so you have two.
Rotate them so that the flat side is facing down.
I made the files different based on how you want to print/assemble
super glue is needed for most of the files