About

Snake Cubes, also called chain cubes or elastic cubes, are puzzles consisting of 27 cubes connected together, usually by a piece of elastic. Every cube (except for the ones at either end) has two faces with a hole in their centre through which the elastic runs. A cube can have holes in opposite faces, so that the elastic runs straight through, or in adjacent faces, so that the elastic makes a 90 degree turn through the cube. The aim of the puzzle is to fold it into the shape of a 3×3×3 cube. There are many versions of this puzzle. Some are made of wood, others of plastic, but more interesting is that different versions have different arrangements of 'straight' and 'bend' cubes on the string. Some of these arrangements are much easier than others. In general, those with more straights are easier because there are fewer degrees of freedom. On the other hand, some versions may have multiple solutions making it easier, too. The most difficult ones are those with unique solutions and not too many straights. This puzzle should not be confused with the Kibble cube. That is also a string of cubes, but its cubes has slots that allow the elastic to change the faces it enters and exits. There are also versions of the snake cube where it is easy to make a cube, but where the aim is to make one with a particular colour pattern. I will not discuss those here. One of the hardest versions of the snake cube is Kev's Kubes (version 9B), made by Trench Puzzles. It is made from wood, alternately coloured white and black. A plastic version called Cubra comes in 5 variations, each with a different colour. In order of difficulty, they are Mean Green, Bafflin' Blue, Twist yer 'ead Red, 'Orrible Orange, and Puzzlin' Purple. Almost all other versions of the snake cube have the same shape as the Cubra Blue. If we denote the straights, corners, and ends with the letters S, C, and E, then the type of snake cube is easily given by a string of 27 letters. Here are the snake patterns some of the commercially available puzzles: ESCCCSCSCCCCCCCCCCCCCSCSCCE Kev's Kubes (9B) ESCSCSCCSCSCSCCCCSCCSCCSCSE Cubra Green ESCSCSCSCCCCSCSCCCSCCSCCCSE Cubra Blue ESCCCCCCCCCSCCCCCCCSCSCCCCE Cubra Red ESCSCCCCSCCCCCCCCSCCCSCCCSE Cubra Orange ECCCCSCSCCCCCCCCCCCSCSCCCCE Cubra Purple The Cubra Red has 10 solutions, the Cubra Purple has 6, and all the rest have unique solutions (disregarding mirror images or rotations). If your browser supports it, you can click on the link below to play with a Javascript version of the Snake Cube.