The skewb page

The skewb is a cube shaped puzzle, like the Rubik's cube, except that its turns are based on rotating the corners rather than the faces.

A catalog of skewb moves

The goal here is to collect enough moves to support the following solution strategy: fix the centers and solve the corners using "clean corner moves" (i.e., moves which do not effect the centers).

The basic moves are twists by 120 degrees clockwise about each of the eight corners FRU,FLU,BRU,BLU,BDR,BDL,DFR,DFL. For example, here's a picture of the move FRU . The inverse of a move m will be denoted m^(-1) and the composition of two moves m1, m2 will be denoted m1*m2 (move m1 first, then m2).

Let [a,b]=a*b*a^(-1)*b^(-1).

• FRU = BDL (actually, they are only equal up to a rotatation of the entire cube). In general, a corner move is equal to the opposite corner move up to a rotation of the entire cube.
• FRU*BLU*FRU^(-1) is order 3.
• (FRU*FLU)^3=(FLU*FRU)^3 twists 6 the corners clockwise by 120 degrees. The 2 corners not twisted are those opposite the FRU, FLU corners: the BDR, BDL corners and the centers are all left fixed. It does not permute any facets.
• The move [FRU*BLU]^5 fixes all the centers and the 2 "opposite" corners: DFL, BDR. It twists the 3 corners FLU, BLU, and FRU. On the remaining 3 corners, it acts as the permutation (DFR,BRU,BDL).
• (FRU*FLU)^6*(BDL*BDR)^6 rotates (but does not permute) the corners (the uf corners ccw, the df corners cw, the ub corners cw and the db corners ccw). It does not permute any facets.
• bottomspin=(FRU*FLU)^6*(BDL*BDR)^3*(DFR*DFL)^3 rotates the 4 bottom corners (the df corners cw and the db corners ccw). It does not permute any facets.
• FRU = BDL (actually, they are only equal up to a rotatation of the entire cube). In general, a corner move is equal to the opposite corner move up to a rotation of the entire cube.
• (FRU*FLU)^3*(BDL*BDR)^6 rotates all the corners except for the bu and the df corners (the uf corners cw and the db corners ccw). It does not permute any facets. (FRU*FLU)^6*(BDL*BDR)^3 is the same move, but rotates in the opposite direction. (FRU*FLU)^3*(BDL*BDR)^6 .
• (BRU*FLU)^9 is a 5 cycle on the center facets (F,R,B,U,L). It fixes the bottom and does not affect any corners.
  (BLU*FRU)^9 is a 5 cycle on the center facets. It fixes the bottom and does not affect any corners.
• (BLU*FRU)^9*(BRU*FLU)^9 is a product of 2 2-cycles on the center facets, swapping front/back and up/right. It fixes the bottom and does not affect any corners.

  A MAPLE skewb package

  The MAPLEV3 or better skewb package has routines to simulate the movements of the skewb on the computer. Here is a MAPLEV5 example worksheet skewb1.mws to illustrate the commands.

  Maintained by David Joyner

  Last modified 6-6-2004.