Square-1 (puzzle type)

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Square-1
Square-1 twists.jpg
Square-1 into a solved position
Alternative names: Cube 21, Back to Square One
Shape: Cube
Internal Mechanism: Square-1
Inventors: Karel Hrsel and Vojtech Kopsky
Year: 1990
Produced by:

The Square-1 (short for Back to Square One, also known as Cube 21) is a cubic twisty puzzle, with irregular cubies. It's one of the most popular shape-shifting Rubik's Cube variants.

Description

It has only 2 axes of rotation (the top/bottom faces and the entire right/left half of the puzzle). The puzzle consists of two halves, each with corner and edge pieces indistinguishable to the core. That means that corners can be swapped with edges and otherwise. The top and bottom layers consist of triangular edge pieces and quadrilateral corner pieces. The middle layer consists of two trapezoidal pieces. When scrambled, it shifts to a random shape : it's a shape-shifting twisty puzzle.

Goal

The goal is to return the cube to its cubic state with each side one solid color. For the silver variation, the goal is only to return the cube to its cubic state.

History

  • Early 1990 : Invention by Dr. Karel Hrsel and Dr. Vojtech Kopsky.
  • Early 1990 : Original version is produced by Dr. Karel Hrsel and Dr. Vojtech Kopsky.
  • 8 November 1990 : Czechoslovak patent filed on 8 November 1990.
  • 26 October 1992 : Czechoslovak patent approved on 26 October 1992 with patent number 277266 B6.
  • 7 November 1991 : USA Puzzle patent filed .
  • 16 March 1993 : USA Puzzle patent approved 16 March 1993 with patent number 5,193,809.
  • 26 December 1990 : USA Design patent filed .
  • 5 October 1993 : USA Design patent approved with patent number D340,093.
  • 1999 : A version of square-1 with a Cube-21 logo is produced. This is the european version of the cube. The logo was "Cube-21", which is a short for "Cube for 21th century", as it had been produced in 1999. It had also been produced the same year with a "silver edition". In this variation, there are only 2 colors and the goal is simply to shape it back to a cube.
  • 2003/2004 : WCA is created. Square-1 became an official WCA event.
  • 2007 : MF8 also produces the Square-1 s. ince 2007. It became more popular.
  • 2010 (or before): CubeTwist also sells a Square-1 produced by YJ since 2010 or before.

Methods

The puzzle is much easier to work with when it is in the shape of a cube so generally the first step is to somehow (there are several methods) get the pieces arranged so that the puzzle is cubic. Then, the pieces are separated into their correct layers, and permuted. Note that there is no possible incorrect orientation for pieces, since the middle layer can only rotate through 180 degrees at a time (many talks about separation as "orientation").

Where to buy

They can be found on Lightake [1] [2], on ThatCubeStore [3] and on many other strores.

See also

External links



Cubic twisty puzzles

2x2x2 | 3x3x3 | 4x4x4 | 5x5x5 | 6x6x6 | 7x7x7 | more...

Skewb | Master Skewb | Rex cube | Dino cube | Helicopter cube | Curvy Copter

Crazy 4×4×4 cube (version 1) | Crazy 4×4×4 cube (version 2) | Crazy 4×4×4 cube (version 3)

Gear cube | Gear cube extreme

Constrained cube (90°) (mechanism variation of 3x3x3) | Void cube (mechanism variation of 3x3x3) | Latch Cube (mechanism variation of 3x3x3)

Void cube | Shepherd's cube (sticker variation of 3x3x3) | Labyrinth cube (sticker variation of 3x3x3) | Supercube (sticker variation of NxNxN cubes)

Square 1 | Square 2

Bandaged cube