Cube solving (part 1)

Cube solving (part 3)

2. Solve edge pieces

The goal of this section is to order the edge pieces so that each 3 edge pieces (2 outer edge pieces and 1 middle edge piece) in the same colours are positioned side by side. At the same time the order of the side pieces (as reached in section 1) shouldn't be destroyed. To reach this goal, at the middle layers are only 180° turns allowed now.

2.1 Solve edges 1 to 7

When there's used the word "edge" in this section, a 3-piece combination consisting of 3 neighbouring edge pieces is meant with that. Therefore an edge consists of 1 middle and 2 outer edge pieces. Applet 2a shows the principle way to order the edges: Look for a middle and an outer edge piece which each have the 2 same colours. Place these edge pieces on 2 opposite edges so that they would be placed side by side after a 180° turn at a middle layer. At this you have to take care that the colours of the outer edge piece aren't exchanged in comparison with the colours of the middle edge piece. Now look for the second outer edge piece with the same colours like the first. At the second outer edge piece you don't have to pay attention to the colours, because at the two equal outer edge pieces the colours always match when they're placed at the same edge. The reason for this is that two outer edge pieces, which exchange their positions will exchange their colours, too. Strictly speaking, there are no two equal outer edge pieces: One, for example, is blue on the left and white on the right side, the other is white on the left and blue on the right side when it's placed on the same position. Depending on which colour is left or right at the middle edge piece, one outer edge piece has to be inevitable above and the other has to be inevitable below the middle edge piece that the colours of the outer edge pieces will match with the middle edge piece.
Of course, you can also order the 2 outer edge pieces first and then turn the middle edge piece between them in the matching colours.

Applet 2a	Applet 2b

Place the solved edges along the top and bottom layer. At first put only each 3 solved edges on top and on bottom, that at least 1 "free edge" (edge with still unsolved edge pieces) is on top and on bottom layer. If you want to do a 90° turn on a side (outer layer which is placed left, right, in front or behind), first turn the top and bottom layer that this side which you would turn at 90° both on top and on bottom has free edges. Thereby you can avoid that an already solved edge comes to a place on which it would be mixed up by solving the next edge along a horizontal middle layer. Applet 2b shows the solving of an edge when already 6 edges are ordered. Finally this 7th ordered edge has to be turned up or down, too.

If an edge piece is already on the right position, but its colours needs to be exchanged, one of the following combinations is helpful. Applet 2c is the shorter combination but you can do it only if little edges are ordered and if they don't leave their positions. Applet 2d you can do always, no matter how many edges are solved.

Applet 2c	Applet 2d

2.2 Solve edge 8

Proceed with solving the 8th edge just the same as explained under point 2.1 and put it with the following combination (applet 2e) on the place of the last free edge at the upper or lower layer.

Applet 2e

2.3 Solve edge 9

Now solve edge 9 as described under point 2.1 and put with the following combination (applet 2f) an already solved edge to that position which is opposite to the edge you've just solved. Each 2 solved and 2 unsolved edges thereby are now opposite to each other, the 3rd unsolved edge is on top or on bottom.

Applet 2f

Note: The only difference between applet 2f and applet 2e is that the first turn is left out, with which the last free edge is put on the right position in applet 2e.

2.4 Solve edges 10 to 12

2.4.1 Solve edge 10

The 10th edge can be solved with the known method, but you must pay attention to the following points:

• Exchange, if necessary, two unordered edges with the help of combination 2f.
• To twist an edge at 180° use the method shown in applet 2d.
• To reach that 2 already ordered edges which are in the turn area of the middle layers won't get completely disordered, you should no longer turn the central middle layer but only the outer middle layers.
• Always turn the same outer middle layer. You reach this by specific use of applet 2d (If you use applet 2d on both opposite unsolved edges and then turn the lower outer middle layer at 180°, you've reached the same as if you had turned the upper outer middle layer). You reach thereby that at every 2nd turn at the outer middle layer both edges which were already solved get back to their original condition.
• You need to pay attention no longer necessarily that the colours of the outer edge pieces aren't twisted compared with the colours of the middle edge piece. When you solve the last two edges, this even won't be possible with a chance of 50%.

2.4.2 Solve edges 11 and 12 (without matching colours)

Exchange (see applet 2f) the 10th solved edge with that unsolved edge which is placed on the top or on the bottom layer. Now both unordered edges are opposite to each other. Solve these edges following also the points explained above (point 2.3.1). Before you make the very last turn (turning an outer middle layer), you should have a look at the condition of both original solved edges. There are the following 2 possibilities:

1. These edges are unsolved and can be solved also by turning an outer middle layer: If necessary, execute applet 2d and then solve all remaining 4 edges together by turning the correct outer middle layer.
2. These edges are already solved and would get unordered by turning an outer middle layer once again: In this case do the following applet (applet 2g):

Applet 2g

At first an unsolved edge is turned at 180° by using applet 2d so that with the next turn both solved edges get unordered and both unsolved edges stay in their unordered condition. After additional use of applet 2d, all 4 edges can be solved together now with one turn. At the turn combination of applet 2g applet 2d is extended by one turn (at an outer middle layer) and the whole combination is made twice.
In the shown example all edge pieces are positioned right after use of applet 2g, but the green/white outer edge pieces are "twisted" (the colours are exchanged) wrong compared with the green/white middle edge piece. What you have to do in this case is explained in point 2.3.3

2.4.3 Get matching colours

Now all edges should be solved (apart from colour matching). What you have to do now is depending on at how much edges the colours of the outer edge pieces don't match with those of the middle edge pieces. If the number of wrong edges is even, place each 2 edges opposite to each other and do applet 2h. If the number is odd, it will get a little complicated. In this case do applet 2i at first.

Applet 2h	Applet 2i	Applet 2j

At applet 2h the horizontal central middle layer is turned by 180° at first. Then you must continue with applet 2d. Through this you've reached that at one of both edges which colours didn't match the middle edge piece has been "twisted" (its colours have exchanged) and at the second edge both outer edge pieces have been twisted. This has the consequence that with an repeated turn at the horizontal central middle layer the colours match at all edges.

At applet 2i you turn alternately an outer middle layer (90°) and an outer layer (180°) so long till the order of the side pieces is regained. If you order the edges again now (as described under point 2.2), all edges are ordered then (if exactly 1 edge wasn't OK) or the number of edges which colours don't match is at least even (e.g. 2 if there were 3 bad edges before). This can be solved by using applet 2h.

Applet 2j shows the complete combination of turns which are necessary to solve the edges after applet 2i: There's one outer edge piece in the same colours as the middle edge piece at each of the 4 unsolved edges, the second edge piece has the colours of a different edge. Each 2 of the outer edge pieces which are at the wrong place are placed above, the other 2 are placed below. Through double use of applet 2d you get either all these edge pieces up or all down. After that you can solve 2 edges by a 180° turn at an outer middle layer, with a 180° turn at an outer layer you place the remaining 2 unsolved edges opposite to each other. Now the situation is similar to that at the beginning of applet 2g. You have to use applet 2g now, but you must leave out the first 7 turns which are the same as in applet 2d. If your Cube wasn't exactly in the same position as in the example at the beginning of applet 2i, maybe you have to use applet 2h once again to complete solving of the edges.

Cube solving (part 1)

Cube solving (part 3)