I could not get a PLA print of Emmett's folding cube to snap together without damaging the hinges, so I re-designed them. The hinge pins are rounded rather than conical, and there is a slit in the hinge to provide a bit more give when the pieces are snap-fitted together. While I was at it I decided to change the outward appearance to an 8-bit pattern to make it stand out from Emmett's original - which I think is awesome by the way !

You need to print two sets of the four pieces. The pieces snap fit together with a bit of force. Keep them even so both pins snap at the same time. Examine the photos to see how the different pieces fit together.