The version shared by Rich Gain on thingiverse needed the thicker bottom layer trimming off in order to fit together nicely. I downloaded burrtools:http://burrtools.sourceforge.net/, and re-exported the puzzle pieces with 0.15mm offset, allowing for easy assembly but keeping the final puzzle piece tight enough. printed a few in different colours on the Kossel Mini.For more details on the puzzle , designer and the solution see:http://puzzlewillbeplayed.com/3BoardBurr/Carbon/