Date: Sat, 11 May 91 03:47:40 -0400 (EDT)
From: "Dale I. Newfield" <dn1l+@andrew.cmu.edu>
To: Cube-Lovers@life.ai.mit.edu
Subject: Re: 5by cubes
Cc: Cube-Lovers@life.ai.mit.edu

(Don't read if you don't want!)

Ditto!   ;)

>I am only having one problem with the 5x5x5 cube, though:
>
>X|O|X|X|X
>X|X|X|X|X
>X|X|X|X|X
>X|X|X|X|X
>X|X|X|O|X
   ^   ^
   1   2

looking at the bottom of my cube, the 2 pieces marked O are swaped
sometimes, so that the face is still a solid color, but the sides are
swapped. [ ... ] I can't figure out what causes the swapping.

Dale,

What is wrong is that *one* of the inner planes [marked 1 & 2 above] are a
quarter turn [i.e. 90dgs] out of phase.

1] The way I solve this is to turn one of the planes a quarter turn, [to
get, for example the following]:

>X|O|X|o|X      <--(Where "o" is the other face of the "O" above.)
>X|X|X|Y|X
>X|X|X|Y|X
>X|X|X|Y|X
>X|X|X|Y|X
   ^   ^
   1   2

2] Then, to keep things straight in my head, I then "mark" the new position
by replacing the center cubies in the turned plane to their correct
positions (being careful not to mess with anything else --particularly the
edge pieces):

>X|O|X|o|X
>X|X|X|X|X
>X|X|X|X|X
>X|X|X|X|X
>X|X|X|Y|X
   ^   ^
   1   2

There's a relatively simple operator to do this, which I leave as an
exercise for the reader. ;)

(It's probably better to do this to all affected four faces, but you can
save this until you have solved the edges.)

3] This leaves you five inner, non-central edges to solve. But it should
be straightforward, so long as you be careful not to mess up anything else.

Nichael