I've just added a script to Thingiverse that allows the STL for 3x3x3 mods to be created using their customiser application http://www.thingiverse.com/thing:56574
(you need an account to run it)
I'm broadly happy with the way the script works but I'm now looking to make the pieces a little easier to print on FDM printers without the need for quite so much support.
Does anyone know of any cubes where the edge and corner pieces have caps that can snap on/off in the same way as centers on a standard Rubik's? Ideally with internal pieces the same shape as a diamond cube (http://twistypuzzles.com/cgi-bin/puzzle.cgi?pkey=392
) but with each face allowing a cap to be added
If such a cube exists it could save a lot of design/print time.