# Solving the peach rubik's cube

I've recently got hold of a peach rubik's cube, which has some interchangeable pices (corners and edges as far as I can make out), and also some edged whch seem to be reversable. Whatever I do, I seem to end up with one face 90 degrees out. It's new, and hasn't been taken apart, so I assume I'm going wrong somewhere with one of the interchangeable pieces, but I can't figure out what.

This is the first cube I've attempted in a a very long time, and what little I ever knew about them or the theory behind them I've forgotten, so I'm hoping someone could suggest where I might need to look to solve it. Would swapping corners make a difference to the orientation of a single centre? Or is that not possible?

Let me start with the answer. If everything is solved except for a single 90 degrees rotated center, it means:

both two identical corners and two identical edges are swapped. So look for two identical corner pieces, and put one of them in the position of the other. Then resolve everything else with your preferred 3x3x3 solving method.

A single 90 degrees rotated 3x3x3 center is actually rather special. A regular 3x3x3 picture cube or shapemod, with each piece unique, can only have a 180 degrees rotated center with everything else solved.

When you start to involve orientationless and/or identical pieces on your 3x3x3 puzzle, things start to get interesting. The first picture mod that made it possible for everything to be solved except for a single 90 degrees rotated center was the Troll Cube sticker mod from 2012. This sticker mod tried to include all five 3x3x3 'parity' cases on a single 3x3x3: an orientationless edge; an orientationless corner; two identical edges; two identical corners; and because of

the two identical corners in combination with two identical edges,

a single 90 degrees rotated center would be possible in the end.

Mass-produced shapemods like the YongJun 3x3x3 Heart or ZhiSheng/YuXin 3x3x3 Egg are similar as your FaXin 3x3x3 Peach, which makes a sole 90 degrees rotated center possible, with everything else solved.