Summary

This is a cube spirally sectioned into 3 identical pieces. The pieces are offset 1mm to give a little wiggle room. I would avoid scaling this down because as it shrinks the built in tolerances shrink as well. I would recommend printing this with thicker walls so that you can get some sanding and smoothing.

you will need to print this 3 times to make all of the pieces. I have not printed this out to check it.