V-Cube 6 to the internal mechanism, thus making the puzzle more durable. The V-Cube 6b, which has the same "pillowed" shape as the V-Cube 7, was introduced later. There are 8 corners, 48 edges and 96 centers. Any permutation of the corners is possible, including odd permutations. Seven of the corners can be independently rotated, and the orientation of the eighth depends on the other seven, giving 8!×3 combinations. There are 96 centers, consisting of four sets of 24 pieces each. Within each set there are four centers of each color. Centers from one set cannot be exchanged with those from another
Helicopter Cube thus jutting outwards like spikes rather than lie flat on the face of the cube. More subtle changes may also be introduced, which are described later. There are four variants of the Helicopter Cube: If the puzzle is only scrambled using 180° twists, then it is obviously solvable using only 180° twists. However, if some jumbling moves were made, even if the puzzle was subsequently returned to cube shape, it may not be possible to solve it using only 180° twists. The reason for this is that using only 180° twists, each face center piece can only be permuted within