3x3x4 Mixup Plus revisited

 September 2024 I watched twistypuzzling solve a Son-Mum and it inspired me to get out my Mixup cubes and try to solve them. 

3x3x4 Mixup Plus Scramble

Thin layers. 180° on perpendicular layers; 45x° on thin layers. Some scrambling of the white and yellow 3x3s will take place.

White and Yellow Edges. Break up the inner edge pieces from the outer edge pieces.

Corners. Scramble the corners as if it were a 3x3x3.

I think this is it! 3x3x4 Solution Guide based on my blog of June 6, 2020 and personal experiences trying to implement it.

1. Yellow and White Centers. Hold them on R and L for the next step.

2. Reduce the White and Yellow Edges. 

1. Put as many tweaked (not flat) inner edges as possible on M. M45. That flattens them. 

2. Pair up flattened inner edges with outer edges of the same color. Line up a white outer edge at BU with a white inner edge at FD. M up 45°, U2, M down 45°.

3. If there are no more to pair because some outer edges are misoriented, use the center twisting algorithm to orient outer edges, then pair up more.

4. If more tweaked edges need flattened and/or outer edges are in centers, move them to M and M45. Orient the outer corners if necessary.Then finish up the outer/inner pairing. That is, the building of the Yellow and White edges.

3. Move the E-layer pieces to the E-layer. URD should suffice to do this.

4. If possible and helpful use moves like R2 to get edge pieces that are in center spots all on the same layer. Twist the layer 45 to fix them all at once after orienting all the E-layer pieces by taking them to the top, twisting 90°, and taking them back to the E-layer.

5. Permute All Center Pieces to Center Locations Ignoring Color, Use the 3x3x2 Corner Commutator. You don’t have to turn an inner slice since the corners aren’t solved yet. 

6. Yellow and White Layers using Corners First.

7. E-layer Center Re-orientation then Permutation. Permuate using The Move, similar to solving the edges of a 3x3x2.

8. E-layer Outer Edges using the 3x3x2 method. If you get down to a single swap of corners needed, hold the cube so the two that need to swap are neither on the lower left and do U R2 U R2 U R2 U R2 U. The centers are good and the corners will solve now. There is a better way. Get the two edges that need to swap together at one corner. Take the adjacent center to the top and U2. Take it down and replace it with the edges that need to swap. Take them to the top and U2. Take them down and put them back.

9. E-layer Inner Edges. ((u 45° left) L2 (u 45° right) R2) x 2 moves A to B to C. A’s flatness stays; the flatness of B and C change. This is the 3x3x2 Corner Commutator where A is on the top layer in the front.

Making progress but not quite there yet.

3x3x4 Solution Guide based on present personal experience along with my previous notes on the blog June 6, 2020.

1. Yellow and White Centers. Put the white center in an edge spot. Without moving it, move the yellow center to the diagonally opposite spot. Move the layer they are in 45° so they are in center spots. Hold them on the right and left for now. 

2. Flatten white and yellow inner edge pieces as much as possible. How? Line up as many as possible in the M layer. Twist it 45°. Voila. They are flat.

3. Move white and yellow outer edge pieces to outer edge spots as much as possible. Use the Edge 8-move 3-cycle like the one used to do the last 3 E-layer edges of a 4x4 cube.

4. Orient white and yellow outer edge pieces as much as possible. Use the center twister algorithm (I didn’t do it exactly. I kept going clock instead of alternating and ended up unflattening some white and yellow inner edges. 😕).

5. Build white and yellow edges as much as possible. Outer edge at UB. Inner edge at FD. M 45° up. U2. M 45° down.

6. Flatten more? Move and orient more white and yellow outer edges to outer edge spots? Build the rest of the white and yellow edges?

7. Hold yellow and white on top and bottom.

8. Move all the E-layer pieces to the E-layer using like DDUU and UFD.

9. Orient all the E-layer pieces. This is a simple process. Take them to the top, twist it 90°, and take it back to the E-layer.

10. Permute All Center Pieces to Center Locations Ignoring Color. Use the 3x3x2 Corner Commutator. You don’t have to turn an inner slice since the corners aren’t solved yet.

11. Solve white and yellow layers using the Corners First Method.

12. Orient middle layer pieces if necessary using the almost complete center twisting algorithm. (M up) U (M down) (E whatever) (M up) U* (M down).

13. E-layer Center Permutation using The Move, similar to solving the edges of a 3x3x2.

14. E-layer Outer Edges using the 3x3x2 method. If you get down to a single swap of corners needed, hold the cube so the two that need to swap are neither on the lower left and do u R2 u R2 u R2 u R2 u. Lowercase u means the E-layer u only. The centers are good and the corners will solve now.

15. E-layer Inner Edges. ((u 45° left) L2 (u 45° right) R2) x 2 moves A to B to C. A’s flatness stays; the flatness of B and C change. This is the 3x3x2 Corner Commutator where A is on the top layer in the front.