A printable model of a puzzle cube design by Leonardo da Vinci.

Based on CAD files by Travis Petersen at Grabcad, split into STLs for easier 3d printing.

A complete cube needs six faces ("Keyhole" model), eight corners, one core, four “normal” keys and one each of the two long keys. Be sure to sand your parts before assembling, especially the keys and the keyholes! Once assembled, a tight fit can make it really hard to disassemble later.