Saturday, July 27, 2013

How to solve a rubiks cube 2


Second layer



    Once you solved the first layer and the green side, you need to solve the second layer. Turn the cube upside down so the blue side is up. You look around the up side and you need to find a piece in the cross that does not have a blue color, say, its top color is white and its other side is orange. You twist the top layer until that piece is in its correct side, i.e., the orange side in the example. Then you put that side to the front. Then you need to put that piece in the second layer of the same side. To put it on the right of the middle piece, do U, R, Ui, Ri, Ui, Fi, U, F. To put it on the left of the middle piece, do Ui, Li, U, L, U, F, Ui, Fi. Using these two algorithms, you should solve the entire second layer.

 

Last layer



    To solve the last layer and the entire cube, you need to look at the blue side. The blue side usually should have the backward L as shown in Figure II (note that the backward L is on the top left), the line as shown in Figure III (note that the line is horizontal, not vertical), or the cross as shown in Figure IV.




Figure II



Figure III



Figure IV


The goal is to get it to the cross. If you have the backward L, you first need to get it to the line and then you get it to the cross. If you have the line, you just get it to the cross. When you have the backward L, do F, R, U, Ri, Ui, Fi. You will have the line. Then you repeat the algorithm to get to the cross. Once you got the cross you twist the top layer until at least two edge pieces of this cross are in its correct side. Turn the cube so the two correct edge pieces are on your right side and the opposite side. Then you just do R, U, Ri, U, R, U, U, Ri, U. All the top layer edge pieces will be in their correct positions. Here’s the case when the two correct edge pieces are not next to each other. Then you put one in the front and one in the back, and do this: R, U, Ri, U, R, U, U, Ri. Then you have two correct pieces next to each other, and you can do the normal way.




Figure V

On very rare occasions, you may first have the blue dot as shown on Figure V, instead of backward L, straight line or the cross. In this case, you can do F, R, U, Ri, Ui, Fi on any side to get to the backward L. Then you can follow the above instructions.

 By now, you’ve gotten the edge pieces finished. Then you need to get the corner pieces in their correct position. To do that, you need to find a corner piece in its ready position. For example, a piece with colors blue, red, and yellow needs to be in the corner of the blue, red and yellow side. You put this piece in the right top of the front side. Then you do U, R, Ui, Li, U, Ri, Ui, L once or twice to get all the corner pieces in the ready positions. Sometimes you may not be able to find one piece in its ready position, then just start from any side with the above algorithm.

Then you find a corner piece with blue side not on the top, and turn the cube so that it is on the top right of the front side. Then you do Ri, Di, R, D a few times until all the three colors of this piece are in their correct positions. Remember, in this step, you will ruin the bottom two layers, but don’t panic. Believe me, the cube is going to come back in the end.


Then you keep the front side unchanged, and twist the top layer until another unfinished corner piece is on the top right of the front side. You do Ri, Di, R, D until it is in the right position. You repeat doing that until the corner pieces are all in their correct positions. Then you are just one step from finishing your first rubiks cube!!! I believe that you are smart enough to figure out that easy step by yourself.


Congratulations, and I hope this taught you a lot and you liked it. Thanks for reading!