Hi everyone,

This is my first post on twistypuzzles.com. I came here following Oskar van Deventer's posts on the shapeways.com forums. I mostly make 3D printed mathematical sculptures, but some of my recent projects have veered into burr-type puzzle territory, so hopefully this will be of interest.

"The 30-Cell Puzzle" is (as far as we know) a new puzzle, designed/discovered by Saul Schleimer and myself. It is based on the 120-cell, one of the 4-dimensional regular polytopes, the analogues of the 3-dimensional regular polyhedra (the cube, tetrahedron, octahedron and so on). The goal is to assemble the 5 identical pieces shown in the first picture into the ring-like structure shown in the others. Each of the five pieces is made from six dodecahedral cells, giving the puzzle its name.

Shapeways page for the puzzle

YouTube video



Cheers,

Henry Segerman

This looks really attractive but in WSF it will get grubby very quickly. Does the structure rely on the flexibility of the plastic or is it still constructible in a rigid material? I think this would be absolutely fabulous if it was made in exotic woods by a major craftsman!

Yes, it does get a little dirty over time. I've found that washing up liquid and hot water do pretty well for cleaning it up.

It can also wear down and get a little loose over time. Presumably the polished material has fewer problems with friction changing the shape, although it might be difficult to work out how to design it larger, to deal with the lost material in polishing. Does anyone know how uniform the polishing process is? I would imagine that surfaces near a concave corner would lose less material than surfaces on the outside?

I think it does require some flexibility in the material. Someone asked for a larger version in Shapeways' bronze/steel material, which is far more rigid. I haven't heard whether or not they have been able to put it together yet.

Hi Henry,

I watched your youtube videos about this puzzle and also the Dodecahedron chains a few days ago, because Roice Nelson is my friend and he liked your video. I don't know if you know him as well. It's nice to see some 4D objects made in 3D as a puzzle.

I've solved a couple of high dimensional puzzles. We have a small community in this Yahoo group:

http://games.groups.yahoo.com/group/4D_Cubing/

Although we make and play with mostly computer simulations of high dimensional puzzles, I'm sure many people will appreciate your 3D printed puzzles. Would you like me to introduce you and your work in that group?

Hi schuma,

Yes, I've met Roice a few times, and I've talked with him and Scott Vorthmann about 4D visualisation. Roice's MagicTile project is beautiful work.

Sure, please do let people know about my stuff if you think it's appropriate! I only have the one puzzle-like thing at the moment, although we are working on more. The 4D group might also be interested in the other things I've done with 4-dimensional polytopes:

http://www.shapeways.com/shops/henryseg?section=4+Dimensional+Polytopes

Cheers,

Henry