Menger sponge with external support

Original creator description

The Menger sponge is quite difficult to print on a standard filament-based 3D printer; it's full of overhangs. Internal support won't work because it can't be removed, which leaves nice Menger sponge prints in the domain of other 3D printing technologies. On the other hand, the shape prints just great on the diagonal, as a few people have noted . That means it would be possible to print a sponge on the diagonal and glue the halves together, but that seems like cheating. If you could print the sponge standing on a corner that would be fine, but it would certainly fall over within a few layers. I tried a couple of times to use automatically generated support from different software packages,... This hosted file keeps creator credit and license details.