## Sunday, August 7, 2011

### 3x3x4 Cuboid

The 3x3x4 Cuboid is a twisty puzzle, where, due to its cuboid shape, the side faces can only be turned 180°. Well, actually you can turn them 90° also (and anything in between) but if you want to do any other turns, 180° is the go. This makes for a different movement of pieces than we see on the Rubiks cube. It's assumed you can solve a 3x3x3 Rubiks cube as well as a 3x3x2 cuboid.

The Basic Plot
1. Reduce the edges.
2. Reduce the corners.
3. Solve the reduced 3x3x2
Step 1: Reduce Edges

The first step is to reduce the edges. This means attaching the top/bottom layer edge pieces to their correct colours in the middle layers. We use F2 U F2 U' and similar to do this.

It's possible to end up with 2 edges needing to swap. Due to the multiple colours of each edge, this is just a 3-cycle.

Step 2: Reduce Corners

To attach outer corners to inner corners, we use the corner piece series for cuboids, and its mirror.

(U R2 U' L2) x 2  cycles UBL->DFL->DFR
(U' L2 U R2) x 2  cycles UBR->DFR->DFL

If two corners need to swap, simply turn the upper face one turn, then re-reduce edges and re-reduce corners.

Step 3: Solve Reduced 3x3x2

Now solve the reduced cuboid as though it were a 3x3x2.

And that's it. Your 3x3x4 Cuboid is now solved. I trust this site has been helpful. If you have any questions or want some clarifications, please use the comments to do so. To buy this puzzle, click here.

1. Congratulation for the web site!!

BUT:
Help! I Need To Swap Two top Edges in opposite position.

I tried the system that you propose for the middle layers but i am seeing that is incorrect for the top layer.
what do you propose?
regards
dario

1. Hi Dario

If you have to swap two edges on the top layer, it doesn't matter if they're in adjacent positions, or opposite positions. You need to turn the top face one turn. That fixes the problem. All you do then is re-solve the edges, using two edge piece series.

However, once that's done, you'll find there are 4 3x3x2 corners unsolved. You just solve them as you normally would. Then re-solve everything. It's a bit long, and there's no quick fix algorithm that I have, but it works. Give it a go. If it's not working, let me know and I'll make a video for it.

2. Hi Chareaves