How to Take Apart a Rubik's Cube and Put It Back Together

Before you start: what pieces are inside?

According to Wikipedia, a 3x3 cube has a core shaped like a 3D cross that holds the six centres, plus 12 edges (two colours) and 8 corners (three colours) (Wikipedia). Every edge and corner has a hidden "foot" on the inside that hooks into the pieces next to it, so the whole cube holds together without any glue.

When you take the cube apart, you only remove the edges and corners. Leave the core and the six centres where they are. Ruwix warns that taking the centres off too can mix up the colour scheme of the cube (Ruwix). The centres never swap places with each other, so they are your "map" for putting everything back.

The eight corners (in the picture, only the corners are coloured in):

The twelve edges:

In each pair of pictures above, the left one has the top layer one move off and the right one is the solved cube. The pictures are only there to help you tell which pieces are corners and which are edges.

What you need

• Solve the cube before you take it apart. Starting from a solved cube makes rebuilding easiest, because you know exactly where every piece belongs.
• A tray or box so the pieces don't roll away. iFixit suggests keeping the corners and edges in two separate groups (iFixit).
• If the cube is stiff: something flat and not sharp to pry with, like a plastic card or a small flat-head screwdriver.
• If the cube has tension screws: a cross-head screwdriver. iFixit uses a Phillips #3.

How to take apart a Rubik's Cube, step by step

1. Turn the top layer about 45 degrees, which is half a move, so the top layer sits at an angle to the two layers below.
2. Pry one edge of the top layer upwards. Put your finger or a plastic card into the gap at the angled corner and gently lift the edge out. Ruwix says to use a screwdriver if the cube is stiff, and if it is still too tight, turn a side face slightly off so that edge's foot can slip out (Ruwix).
3. Take out the other pieces. Once the first edge is out, the two corners next to it come loose and fall out easily, and then the rest of the layer follows.
4. Work your way down layer by layer until only the core and the six centres are left.

Wikipedia describes the same method: turn the top layer 45 degrees and pry out one edge, and that is enough to take the cube apart (Wikipedia).

Two things to keep in mind:

• Don't force it. Prying too hard can snap a piece's foot. If a piece won't come out, line the layer up more carefully and try again.
• Newer speed cubes can be harder to take apart. A comment on the Ruwix page points out that many new cubes have edges with "wings" on the inside, so this prying method may not work. In that case, loosen the screws under the centres first (see the screw section below) to make it easier.

How to put a Rubik's Cube back together, following the solved cube

The rule: every piece must sit next to the centres of the same colours. The white-red edge goes between the white centre and the red centre; the white-red-blue corner goes between those three centres. Put it together this way and the cube will always be solvable.

Rebuild it layer by layer, as both iFixit and Ruwix suggest (iFixit, Ruwix).

Layer 1: the white face

1. Attach the four edges with white on them around the white centre, each one matching the colour of the centre beside it.
2. Turn the white face to the bottom.
3. Slide the four white corners in between the edges.

In the picture, the cube is held with yellow on top, so the white layer is at the bottom. The white-layer pieces are coloured in. This layer must line up with the centres next to it, like the picture on the right:

1. You start with (input)
3. After the formula

Layer 2: the four middle edges

Put the four edges that have no white or yellow into the middle layer, from the top down. Each one must match the two colours of the centres beside it: the red-green edge goes between the red centre and the green centre.

After this step, the bottom two layers are complete (coloured in the picture):

Layer 3: the yellow face and the last piece

1. Attach the remaining yellow edges and corners. iFixit suggests turning the top layer 45 degrees when you put the corners in (iFixit).
2. The last edge is the trickiest. Turn the top layer 45 degrees, gently pull the two corners on either side outwards, tilt the edge in and press until it slides into place. Ruwix says gently turning a side face can also help the last piece click in.
3. Turn the top layer back so it lines up.

When you are done, the yellow layer (coloured in) must line up with the rest of the cube:

Check it after rebuilding

Once it is back together, don't scramble it straight away. Do two quick checks to make sure the cube still turns smoothly and no piece is loose.

Check 1: do R U R' U' six times. Doing this four-move set six times in a row brings a solved cube back exactly to how it was. If the cube isn't back to normal after six times, you made a wrong move; try again more slowly. If a piece pops out along the way, the cube is too loose.

The left and right pictures look exactly the same, and that is just what you want to see. The coloured pieces are the seven pieces that R U R' U' moves around each time; after the sixth time, all seven are back in place.

Check 2: scramble with three moves, then undo them. Do R U F, then undo it with F' U' R'. The cube should be solved again.

1. You start with (input)
3. After the formula

The left picture is the cube after R U F, the right picture is after F' U' R'. This check doesn't prove the colours are in the right places; it only tells you the layers turn smoothly and no piece is out of line. The colours will be right as long as you followed the centres as shown above.

What if you put it together wrong?

Ruwix works out that if you put the pieces in at random, the cube will be solvable only about 8% of the time (Ruwix). Wikipedia explains where that number comes from: if you count every way of taking the cube apart and putting it back, there are 12 times as many arrangements, and only one in twelve of them can be solved by turning (Wikipedia). 1 in 12 is about 8%.

The three most common mistakes when a cube is put back wrong are a twisted corner, a flipped edge, or two pieces swapped with each other. How to spot and fix each one is in the post Unsolvable Rubik's Cube: 3 assembly mistakes and how to fix them.

Ruwix also mentions another way for people who can already solve the cube: put the pieces in any old way, solve the cube until you get stuck, then take out just the wrong pieces and put them back correctly. This is quicker than hunting for each piece, but only use it once you can solve the cube comfortably with the beginner's method for the 3x3.

Adjusting the screws: cube too loose or too tight

Many cubes have a screw and a spring under each centre. According to Wikipedia, older official Rubik's Cubes have adjustable screws, newer ones use rivets that can't be adjusted, and many cheap cubes only have plastic clips with no screws or springs (Wikipedia).

If your cube has screws:

1. Pop off the small cap on the centre with a fingernail or something flat.
2. Turn the screw with a screwdriver. iFixit suggests tightening it about half a turn to a full turn if your cube keeps popping (iFixit).
3. Adjust all six faces the same way, then put the caps back on.

Ruwix recommends keeping the tension somewhere in the middle: too loose and it turns easily but pops more, too tight and it is hard to turn. iFixit adds that a tighter cube pops less but is worse at "corner cutting", which means turning when the layers aren't perfectly lined up.

Why take a cube apart?

• To fix a cube that popped. You don't need to take it all apart; just put the fallen pieces back in, following the centres as above.
• To clean and lube it. Ruwix says speedcubers often take their cubes apart to add silicone lube so they turn faster.
• To fix a cube that was put together wrong. See the post Unsolvable Rubik's Cube.

Sources

• How to take apart and disassemble a Rubik's Cube – Ruwix
• How to Fix a Popped Rubik's Cube – iFixit (Giovanni Román et al.)
• Rubik's Cube – Wikipedia