This little puzzle is really cool and surprisingly hard to come by.
The Yoshimoto Cube is a toy that was first invented in 1971, by a Japanese mathematician named Naoki Yoshimoto. He was trying to find different ways to split a cube equally in half and ended up discovering the arrangement.
The cube was first introduced in 1972 at an exhibition, and then later developed for commercial production. In 1982, it was included in the Museum of Modern Art’s permanent collection.
A total of three cubes exist, labelled as “No. 1”, “No. 2”, and “No. 3”. All the cubes are made of Polypropylene. The silver and gold on the cubes appear to be thick semi-metallic stickers (I did not try to pull it apart!), glued on with a heavy-duty glue. Each of the cubes are cut in a special way and the stickers allow for the pieces to stay together while they are being twisted and turned.
The three cubes are as follows:
|Cube Number||Component Shapes||Drawing|
|1||2x Stellated Rhombic Dodecahedron|
|3||1x Rhombic Dodecahedron|
I found Cube No. 3 to be the most interesting as it was not only the hardest one to “solve” but also exhibited some interesting properties. Cube No. 3 was the only cube made up of only one piece which had to be twisted and turned to form the Rhombic Dodecahedron. Another interesting property of the cube is that is formed from a kaleidocycle, which is defined as a ring of an even number of tetrahedra. The ring can be twisted inwards or outwards, and during each step, would show different sides of each of the tetrahedra that form it.
The Yoshimoto Cube No. 1 is very easily available but cubes No. 2 and No. 3 are no longer manufactured, probably due to the high cost and low demand. They came in a foam box with some leaflets (which I assume show you how to fold and unfold the cubes) which I have not opened, because I didn’t want them to lose their creases.
This set of cubes costed me around $300, but such rare items are a great addition to my collection. I really wish I could play with Cube No. 3 some more, but I’m really afraid of damaging it, because these cubes, despite their strong materials of construction, are very fragile. I’ll probably end up making one out of paper just to see what happens.