The "Request an Alg" Thread

Solving a Rubiks style Rhombus

Hi guys and gals!

Been into cubing for a few months now, and can solve a standard 3x3 in about 3 minutes from memory, but my parents presented me with a hell of a challenge at christmas when they gave me a rubiks rhombus : http://www.puzl.co.uk/rhombus-p-348.html#.VsH-Illronk

Basically I've gotten to the point where I've solved 90% of the cube, but for the life of me can't solve the last 2 segments, on the "3rd" layer, two of the centre cubies are orientated the wrong way, and I need to rotate them both 180 degrees in order to solve the puzzle. hopefully these pictures will explain a little bit better : http://imgur.com/gLpG7mI&uRWwPVY

Any algorithms you may know would be a great help!

Cheers all! :tu :tu

I have never seen one before, so I am not sure if it works, but, if it is a 3x3 cube with the shape modified, you could try doing a T-perm twice with the side with the twisted centre on top.
A T-perm goes like this:
R U R' U' R' F R2 U' R' U' R U R' F'

I hope this helped!

Yep, it's difficult to know without actually knowing the puzzle and how it works or what it can be compared with. If you were to compare it geometry-wise with a 3x3 would you say those pieces would be corners or edges or centers? To identify, should just turn a face like 45º and check what is the piece around which the face revolves, that would be a center (independently of the shape and the number of stickers on it), the pieces at the sides of the center would be edges and the pieces between two edges would be corners. Maybe you can send a photo of the face that needs fixing partially rotated so that we can better see. Nice puzzle, by the way, I didn't know about it.

The closest thing I have is the crazy yileng fisher shapemod 3x3. This is what I mean by my explanation above:



As you can see this puzzle has centers with two colors that need orientation, and also 3 color edges and also other edges with just one color that need orientation anyway as they have a short and long side. In this kinds of puzzles there might be edges or corners that don't have orientation, as they have just one color and regular shape but they might affect the cases you can get, which can be different than on a 3x3. For example in a 3x3 you cannot have just one twisted corner but maybe there is another twisted corner that you cannot see because it does not have orientation. That happens, for example in the Mastermorphix 3x3 shapemod:

http://www.cs.brandeis.edu/~storer/JimPuzzles/RUBIK/Mastermorphix/MastermorphixRounded.jpg

In this picture, the small triangular piece under the one with Meffert's logo is a corner without orientation and the piece above, is also a more conventional 3-color corner. So, it can happen that you have just the top corner twisted and if you want to solve the puzzle you have to twist that corner, let's say clockwise and then one of the others anti-clockwise. The latter will remain "solved" as it does not have orientation.

Something like that might be happening to you, that's why knowing the geometry of the puzzle is necessary to help you.

So I'm looking for Algorithms that only use U, u and R. Or U u and L to solve edges For OLL for J shape and Bar (2-look so any corner changing is fine). And a corner PLL alg (like A, T, J, etc.)

ViolaBouquet said:

So I'm looking for Algorithms that only use U, u and R. Or U u and L to solve edges For OLL for J shape and Bar (2-look so any corner changing is fine). And a corner PLL alg (like A, T, J, etc.)

Click to expand...

J shape: R' u' R U' R U R' u R2' U2' R'
Bar: R U2' R2' u' R U' R' U R' u R

Still working on a corner alg

ViolaBouquet said:

So I'm looking for Algorithms that only use U, u and R. Or U u and L to solve edges For OLL for J shape and Bar (2-look so any corner changing is fine). And a corner PLL alg (like A, T, J, etc.)

Click to expand...

T perm:
R2 U' R2 U R2 y R2 U R2 u' R2 u

This is adapted from a domino 3x3x2 alg. It's not possible to permute corners using only U, u, and R, so another face (or y rotation as I have here) is necessary.

To orient UF and UR edges while ignoring corners just do a fat sune: r U R' U R U2 r' (it does use r, so not technically what you're looking for, but still nice and short)

ch_ts said:

T perm:
R2 U' R2 U R2 y R2 U R2 u' R2 u

This is adapted from a domino 3x3x2 alg. It's not possible to permute corners using only U, u, and R, so another face (or y rotation as I have here) is necessary.

To orient UF and UR edges while ignoring corners just do a fat sune: r U R' U R U2 r' (it does use r, so not technically what you're looking for, but still nice and short)

Click to expand...

I can't do any y moves. Only U u and R.

Thank you obelisk. I was just using set up moves to put the two J and bar shapes on the right face, doing a z move and then M' U M' U M' U M' U2 M' U M' U M' U M' then undoing the set up moves. I got a little help from a guy on Facebook for that. Makes perfect sense. I'm wondering now if the corners can't be mixed up after it is solved. It is a conjoined cube and those are the only layers that move. I've only mixed it up and solved it once so I might just have to try a couple times.

ViolaBouquet said:

I can't do any y moves. Only U u and R.

Click to expand...

The moves U, u, and R can't permute corners, it's impossible.

Edit: are you talking about the conjoined cube where a 1x2x3 block is shared? It might be easier to solve if you hold it so you can do r,R, and U moves.

ch_ts said:

The moves U, u, and R can't permute corners, it's impossible.

Edit: are you talking about the conjoined cube where a 1x2x3 block is shared? It might be easier to solve if you hold it so you can do r,R, and U moves.

Click to expand...

Thank you. I just mixed up the cube a few more times and ya, the corners never permute. It turn the cube sideways for the alg that I'm doing now for OLL.

Hello,

Recently got this cube and struggling with OLL and PLL.

I always get it with 2 edges out or all edges ok and the centre in the wrong orientation.

Cant seem to find much about this cube so have been working off 3x3 up to 7x7 methods and some 3x3 axis cubes I have found online. So far nothing to help with this.

See pic, its from the top of the last layer.

ANY advice welcome or am I missing something obvious here??

Thanks

Is that not the PLL parity alg to sort that out? Ie. swapping two opposite dedges, maybe with a simple two-dedge orientation afterwards? Or will the centres then be messed up...? Can 3x3x3 'super-cube' methods/algs be used to sort out the centres independantly, afterwards?
I'm curious, as I was toying with the idea of buying one of these, when I noticed that Kong's UK CubeStore had them in stock. The other thing that strikes me as odd is how normal the Aosu innards are, I kind of expected the 'hidden layer' to be all misshapen as well as the outer, but no...

For UK folks:
http://ukcubestore.com/moyu.html

SenorJuan said:

Is that not the PLL parity alg to sort that out? Ie. swapping two opposite dedges, maybe with a simple two-dedge orientation afterwards? Or will the centres then be messed up...? Can 3x3x3 'super-cube' methods/algs be used to sort out the centres independantly, afterwards?
I'm curious, as I was toying with the idea of buying one of these, when I noticed that Kong's UK CubeShop had them in stock. The other thing that strikes me as odd is how normal the Aosu innards are, I kind of expected the 'hidden layer' to be all misshapen as well as the outer, but no...

Click to expand...

I've tired a parity alg I seen on you tube for a 3x3 axis that swapped opposite sides like I have, but it then changed it to 2 side next to each other (in an L shape) then when I do the parity to swap 2 sides next to each other it just seemed to mess things up, or put them all right but with the centre in the wrong orientation!!....I'll try put the alg up and pictures of the results when I can. Might show it better than me trying to explain.

And I cant find a centre rotation that only rotates one, they all seem to rotate 2 centres......frustrating!

If you are thinking of getting one I definitely would. Took a while to get used to it but once you seen how to hold it etc its pretty cool, get you thinking....my 3x3 and 7x7 now seem very easy lol

Actually could you put the Alg that you would use to swap these? see if its different to what im using?

I should point out I'm a 4x4 amateur.... but:
http://www.speedcubing.com/chris/4speedsolve3.html
should help, and for what it's worth, I would use:
(uU)2 (rR)2 U2 r2 U2 (rR)2 (uU)2
with the dedges to swap being in the UF and UB position.

SenorJuan said:

I should point out I'm a 4x4 amateur.... but:
http://www.speedcubing.com/chris/4speedsolve3.html
should help, and for what it's worth, I would use:
(uU)2 (rR)2 U2 r2 U2 (rR)2 (uU)2
with the dedges to swap being in the UF and UB position.

Click to expand...

Cool, I'll give it a go tomorrow as I have a large quantity of Rum and Pepsi Max in my body at the min, off work tomorrow! ... I'll post when I have give it a go!

ACR85 said:

Cool, I'll give it a go tomorrow as I have a large quantity of Rum and Pepsi Max in my body at the min, off work tomorrow! ... I'll post when I have give it a go!

Click to expand...

I'm a little confused. If you are rotating centers like on a super cuber you can only rotate a sigle side 180° (doing R U R' U five times). If you want to rotate it 90° you need to rotate another side as well.

It also sounded like you were looking or a 4x4 PLL parity to switch adjacent edges instead in opposite ones. What I do is have one edge in the top front and the other on the top right. I then move the right one to the bottom front by doing R2 D' and then do the PLL parity with the Front side on top and reverse the set up moves.

I hope that made sense. I was a bit confused by the questions... so here is a bunch of stuff.

ViolaBouquet said:

I'm a little confused. If you are rotating centers like on a super cuber you can only rotate a sigle side 180° (doing R U R' U five times). If you want to rotate it 90° you need to rotate another side as well.

It also sounded like you were looking or a 4x4 PLL parity to switch adjacent edges instead in opposite ones. What I do is have one edge in the top front and the other on the top right. I then move the right one to the bottom front by doing R2 D' and then do the PLL parity with the Front side on top and reverse the set up moves.

I hope that made sense. I was a bit confused by the questions... so here is a bunch of stuff.

Click to expand...

Hmm maybe I done the centre rotation wrong. I'll have another look at that.

I've managed to solve it! By pure look. I'm guessing my Algorithms were right as I didn't find any different ones and maybe have the cube orientation in the wrong position?

In going to mix the top layer and try again before I scramble the full cube. I'll see what happens!

The algorithm I was using for opposite and side by sides was R U R' U R U2 R' with different cube orientation.

I was pretty confused in the beginning as thought it would solve like a 3x3 after centres and edges completed. But that last layer doesn't have a side colour only top. Strange.


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Right. Totally frustrated at the min. I got stuck on my moyu aosu axis at the same point. Always get past them by trial and error.

I NEED to know what algorithms to use!

1. The last centre orientation. All colours in the right place, two need swapping but keeping all other centres ok. Solve as it is or solve using last two centres at the same time etc. Here is a pic.



2. Will editing this laters.

Thanks. Adam


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PLL A to D algorithm?

Is there a PLL algorithm that switches corner A and D? Cause if there is i can't find it...

There is no algorithm that switches only two corners

What do you mean by A and D? And without even understanding the question, there's no PLL that only swaps 2 corners, it isn't possible on a regular 3x3