# Is it just me or should Sudoku cubes be REALLY easy?



## DAE_JA_VOO (Jun 4, 2008)

I haven't got one, but i've been thinking about it for a few days now. since orientation is so important, the cube should actually be very simple. For example, the middle layer edge pieces can only be in one of the 4 middle layer slots, they can never be confused with the edge pieces on the top and bottoms layers.

The same applies to everything else. The orientation of the cubies is what will eventually help you solve the cube.

Am i missing something?


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## alexc (Jun 4, 2008)

It's virtually the same thing as a Rubik's cube. Also, why is this in the Hardware Area?


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## DAE_JA_VOO (Jun 4, 2008)

I wasn't sure where to put it, as it's not really Speed cubing, BLD or OH 

Yeah, so it is easy then. Cool.


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## Inusagi (Jun 4, 2008)

You could put in it off-topic...

Anyway, they are harder then a normal Rubik's cube, because the center got to rotate the right way.


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## Cubie Newbie (Jun 4, 2008)

Ok, then, which is harder: a supercube (Pochmann cube) or a sudoku cube.


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## DAE_JA_VOO (Jun 4, 2008)

I seriously think a supercube would be more difficult (like a 5x5x5).

I have a 5x5x5 one and i have solved the entire thing except for two center cubies on two of the faces. (granted, i've only spent about an hour trying)


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## shelley (Jun 4, 2008)

I think the hardest part of the sudokube is that if you lose your place (e.g. drop the cube or mess up halfway through an algorithm) it's very difficult to tell which parts are solved and which parts you're still working on.


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## badmephisto (Jun 5, 2008)

I've actually solved one. It took me about an hour. No its not as easy as you think, and I had to devise actual commutators on spot to solve it.

First of all, Its very hard to find the pieces that you need because you have no color feedback. So there goes pattern matching.
Second of all, there is a "5" in the middle. All the 5's have to be oriented correctly, so you need to come up with an algorithm that simply twists centers. Is it possible to twist single center? 2 centers? how? All of this I had to figure out when I solved mine. 



shelley said:


> I think the hardest part of the sudokube is that if you lose your place (e.g. drop the cube or mess up halfway through an algorithm) it's very difficult to tell which parts are solved and which parts you're still working on.


That's also a huge issue. I had to restart entire solve at least 5 times because I lost track of what was solved. 

Lastly my sudoku cube was really tough to turn, so I was getting stuck in middle of doing my PLLs or whatnot, and I forgot which part of the algorithm I was executing. There were a couple of more restarts there.

I dont know, i just found it pretty tough

edit: tough, but obviously trainable anyway. I dont think I would have trouble getting sub 1 minute in 1 day of real actual practice (and with decent cube)


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## jonny guitar (Jun 6, 2008)

Once you realize that the cubes can really only go in one spot (almost all of them anyway), it becomes very easy. The parity issue with the centers is frustrating the first couple of times you get it but simple after that. 

The harderst part of my sudoku cube was the store bought cube was total crap and almost impossible to turn making algos very difficult to execute resulting in screwups that set you back several moves. Cube broke after a few solves anyway. Stickers on a DIY would be a better route.

Get a Shepherd's cube instead...same principle but a little more difficult, more impressive to audience, more fun.


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## kim seung hyun (May 23, 2012)

hello, im dealing with sudokube recently and i got one big problem. i hope you can help me. i tried to solve my cube using lars petrus method, everything was in its place except for top center (5) that is twisted 90 degrees. do you know an algorithm that can correct this? tnx a lot


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## Cubenovice (May 23, 2012)

kim seung hyun said:


> hello, im dealing with sudokube recently and i got one big problem. i hope you can help me. i tried to solve my cube using lars petrus method, everything was in its place *except for top center (5) that is twisted 90 degrees*. do you know an algorithm that can correct this? tnx a lot


 
Check again: either it is 180° turned or there is anothercenter at 90°

To solve: T-perm twists the center 90°
So a single 180° center is solved by 2 T-perms
Two 90° centeres are solved by 2 T-perms too but after the first T-perm you use a slice move to put the other center in the top face - T-perm -undo slice move.

hope this helps


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## shelley (May 23, 2012)

Cubenovice said:


> Check again: either it is 180° turned or there is anothercenter at 90°



Not necessarily. When you're dealing with a cube with interchangeable centers, you can have one center rotated a quarter turn. This can be fixed by a single T-perm, swapping one pair of identical corners and one pair of identical edges.

And for future reference,



Cubenovice said:


> Two 90° centeres are solved by 2 T-perms too but after the first T-perm you use a slice move to put the other center in the top face - T-perm -undo slice move.



^this can be solved much more efficiently. Instead of doing the T-perms, just do a few more slice moves to swap the centers, and fix their orientation with U and U'.


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## Cubenovice (May 23, 2012)

shelley said:


> Not necessarily. When you're dealing with a cube with interchangeable centers, you can have one center rotated a quarter turn. This can be fixed by a single T-perm, swapping one pair of identical corners and one pair of identical edges.
> 
> And for future reference,
> 
> ...


 
THX,
I did not consider the possibility of having interchangebale centers or other pieces.
I only have experience with picture cubes and I don't know if the sudoku cubes falls into this category.
For those that do: *are* there any identical pieces (centers, edges or corners) on your Sudoku cube?

Confused about using U and U' to solve two 90° centers???
U moves affect much more pieces than a T-perm?


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## shelley (May 23, 2012)

Cubenovice said:


> Confused about using U and U' to solve two 90° centers???
> U moves affect much more pieces than a T-perm?


 
Swap centers in and out of the U layer without affecting any other pieces in the layer by using M E' M' or similar.


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