Before starting the tutorial, please introduce the formula used in this step-just one-(r 'u 'r u 'r 'u2r) u (r 'r 'u2r') When you see this formula, your first reaction may be: Why is the formula so long? Don't be afraid, I'll tell you how to recite this formula in the next tutorial!
When we return to the top corner and face the cube to ourselves, a sign with the same three colors will appear on the top floor, which we call "mouth".
The color of "mouth" is not fixed, and it appears randomly according to the situation. No matter how it changes, it will only be red, orange, blue, green, yellow and white. As shown in the figure below (white cannot be displayed due to hue)
What we need to do is to make the mouth face ourselves, and then make the formula (r 'u 'r u 'r u2r) u (r u 'r u u2r') (I'll show you in green here).
After the above steps, a six-sided restored Rubik's cube is displayed in front of your eyes. (White cannot be displayed due to hue)
Special circumstances: During the restoration of the Rubik's Cube, special circumstances will inevitably be encountered. The regression of the top edge is a typical example. As shown in the figure, after the sixth step of "vertex homing" is completed, there may be cases where the "mouth" can't be found on all four sides.
At this time, we can only find the "eyes". What we need to do is to put any front of the Rubik's Cube (emphasis: front! ) Face yourself, and then work out the formula (r 'u 'r u 'r u2r) u (r u r u u2r). If you look again at this time, you will definitely find a "mouth"! If there are "mouths" on all sides, then I think you also know the reason-your Rubik's cube skipped this step and recovered directly.
Remember the formula skillfully: before the teaching begins, I have told you that this formula has a "coup" to remember! And this "coup" is like this:
When you first saw this formula, did you feel a little familiar? That's right! That's it! "Xiaoyu 1" and "Xiaoyu 2" in the fifth step of "Top Color Turn"!
The so-called clever memorization is to point the "mouth" at yourself first, and then make the formula of "Xiaoyu 1" (R' U' R U' R' U2 R). After that, you will find that the vertex angle is "Xiaoyu 2".
At this time, continue to do the formula of "Fish 2" after turning to U (R U R' U R U 2 R'); Together, it is: (r 'u 'r u 'r u2r) u (r u r u u2r). How's it going? Does it feel simple?