I hope you have gone through the articles of solving Rubik's Cube first layer and second layer. So, in this article we shall finish the puzzle by solving the third layer or bottom layer.
See the video for solving third layer of Rubik's Cube using Shanky's Layered approach:
Solving 3rd layer involves following phases:
1. Make a cross of center piece color
- We are asuming that the green center piece is there in bottom layer, so we will make green cross at the bottom (or top when bottom inverted).
- The purpose is to get the green cross like above. Notice that the two below layers are complete.
- So, there will be any of the following situations, it will be either just a green center, or the second fig - an inverted 'L' or the third figure - straight line or the 4th image - the cross itself.
- So, if it is case 1 i.e. first image, perform following algorithm:
- This will take you to case 2 i.e. inverted L. Now perform same steps again. This will take you to 3rd fig i.e. you will get a horizontal line.
- Make sure you keep the line parallel to yourself and then perform same steps and there you go! You will get the blue cross!
- The flow will be like below (Ignore the blue color, here we have to make green):
2. Allign cross edge pieces with the centers of second layer.
Once you got the cross at top, you have to allign the edges of cross with the center piece color of middle layer as shown in below figure.
- So, to get this again you have to perform below steps:
- You may need to perform this step more than once but usually you can get the outcome in 1 or 2 steps only.
Best Practise: Out of the four edges, macth any one edge only and then perform above steps, you can get all edges alligned in one move only.
So now you will find that only corners at top are left to be fixed. To fix the corners we shall first place the corner at right place and then we shall give it proper orienation.
3. Place the corners:
- Placing the corner means all the three colors of corner piece will match with the three nearest centers.
- See the above figure. Here the corner at front is having 3 colors: red, green, blue which is matching with left red center, right green center and the top blue center.
- To place the corner at right place we have to do below steps:
- Again you may need to do this more than once but it will place all the corner at right place as shown in above figure.
- So this corner piece is well placed but not oriented well.
- Next is flipping or orienting the corners correctly
Best Practise: Out of the 4 corners, check if any corner is already well placed. If it is, hold the cube with that corner at the right like shown in the above fig and perform this step, you will get all corners placed well very soon.
4. Orienting the corners correctly.
- So, now we have all corners placed correctly. All that is left to do is give it a proper orientation.
- To orient the corners, perform below steps:
|R U U R' U' R U' R' L' U U L U L' U L
- Once you do above step, you will get the output like any of the two pictures shown above. You may need to do the step more than once to achieve this.
- In above two pictures, ignore the color of top faces, it is blue/yellow. Only focus on the result.
- If you get get case 1 after doing this step, hold the cube so that it looks like case 2 i.e. two of the top face color corner should be in right face like in case 2 fig.
- If you get case 2, you are at the final step. Just do the same step once more and this is it!!
- You have solved the puzzle! The Rubik's Cube will look like this: