Rubik's Cube.
3 plates easy to 3D Print.
I used orbital gears instead of circular(sphere not rings).
I believe that the movement will be more soft ...and flow.
Very strong pieces.
__All you need:__ 6 x screws 25mm and diameter 3mm. 6 x washer for 3mm diameter screw. __Attention:__ * The central piece with the screw need free rot...ate in it. * __DO NOT TIGHTEN__ the screw to lock the piece. * Use the washer between the center piece and the core, the rotation movement will be better; * If necessary use super-glue inside the core hole to fix the screws. * Use flat head screws.