Just about the first thing I did with my glowforge was cut out some fractals, which I’ve posted about a bunch in this thread. That included some variants on what I’ve called a Menger pseudo-sponge: basically a small box that’s a modified six-sided cube with holes that mimics the exterior of a fractal object called a Menger sponge. It looks pretty cool, but…

But I wanted to push my Menger pseudo-sponge into a proper Menger sponge with internal walls. The inside of a Menger sponge, the bits that you see when you look into the holes on the exterior, should be an enclosed series of square tunnels.

Which is a much more elaborately 3D object than the boxy shell I started with. And the glowforge isn’t a 3D printer, so I had to figure out a complicated assembly of flat parts for something much (relatively) larger than the thickness of the material.

So I spent some time the last couple days working out drafts of the pieces required to assemble one.

What that shook out to was: there’s six outer cube-like faces on the sponge. Each of those has a tunnel in the middle, like a square donut, and those six tunnels each converge at a central open space in the exact center of the cube/sponge object.

One image per post, so I’ll lay out a bunch of replies here for the details.