Rubik's cube: Difference between revisions

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==== White sticker RIGHT ====
==== White sticker RIGHT ====
* Edge on 2LL 2LL:
* Edge on 2LL 2LL:
:* Case 1, edge correct ('''L1, BL'''): mirror of above, get a /L1/ using '''BL''' corner, and '''U''' then '''L' ''' move: <code>y U L' U L U2' L' U L y'</code>.
:* Case 1, edge correct ('''L1, FL'''): mirror of above, get a /L1/ using '''FL''' corner, and '''U''' then '''L' ''' move: <code>y U L' U L U2' L' U L y'</code>.
:* Case 2, edge wrong ('''R2, BL'''): mirror of above, get a /R2/ case using '''BL''' corner, and '''U''' then '''L' ''' move: <code>y U L' U' L y' U' R U R'</code>
:* Case 2, edge wrong ('''R2, FL'''): mirror of above, get a /R2/ case using '''FL''' corner, and '''U''' then '''L' ''' move: <code>y U L' U' L y' U' R U R'</code>
* Edge on LL, non-adjacent
* Edge on LL, non-adjacent

Revision as of 23:57, 18 December 2014

This page is a stub.

Links

Official
Guides & Wiki
Tip Videos
Some cool finger tricks. Don't leave your finger from the cube most of the time.
More nice exercices to do (RUR'U', L'U'LU, RUR'F...)
Overshoot move: U' R' F R, swap an edge on the cross: R' u R' u'
See #Tutorial section below
See #Tutorial section below
Video on how to move F2L to FR column.
  • Cube rotation: y U' L' U L. Quite slow.
  • Sledgehammer: F R' F' R (or see variants below).
    A bit faster, no cube rotation. Use it for inserting your last f2l pair for partial edge control of your OLL, or to avoid moving your next pair if you've spotted it using look ahead. Apparently the F' is done with the thumb, a bit before doing the R.
  • Case Number 2: F' (r U r')
  • Case Number 3: r' U' R U M' — What about B' R B R' ?
  • Case Number 4: l U L' U' M' — What about B L' B' L ?
When to use the sledgehammer (right-handed left variant): R' F R F' , or "RU" prime: U R U' R' (i.e. sexy move prime).
The goal is to end up with 4 well-oriented edges in the OLL.
http://cubesolv.es/ (reconstruction db for WR...), speedsolving.com forum and wiki, alg.cubing.net, wca, www.qqtimer.net
Solutions
Shops
Sell the recommended lube lubix's lube, but oversee, so high shipping and custom cost.
The Lubix silicone is made of a polydimethylsiloxane polymer. Note this is the same lubricant that Rubik's sell in their Rubik's Speedcube Pro Pack.
Sell Maru lube (not recommended, see below), Calvin's lube high viscosity and Calvin's lube medium viscosity (seems very good).
Sell Zhanchi's cube, but not black ones.
Tools
z = U            p = z       h / g = F / F'
r = Lw', l       q = z'      i / k = R / R'
t = x'           j = U       d / e = L / L'
y = x2           m = r'      j / f = U / U'
u = Rw, r        x = U'      s / l = D / D'
i = R            v = l       w / o = B / B'
                                           
space = scramble             a     = y'    
                             n / b = x / x'
  • alg.cubing.net — Great & clear cube visualizer, view your moves, simplify & mirror them.
On GitHub. Installed locally at http://localhost/alg.cubing.net/index.html.

Apps

Android

Games
A rubik's cube game. A bit though to manipulate.
Timers
A simple speedcubing timer with scrambler algorithms support. Very nice design, all on one single page. Best out there.
A timer for speed cubing. Some ads and no much features.
A timer for speed cubing. Scramble algorithm. No graph.
A timer for speed cubing. Scrambe algorithm. No graph. Compare cube brands. Too many pages.
A timer for speed cubing. Scramble algorithm. Graph. Design not as good as Rubik's Stopwatch. Additional resources like algo, WCA regulations.

A simple, elegant timer with WCA scrambles for recording Rubik's cube solves. Graph and history by session (best, best AO5), scramble image, double touch inspection.

Solvers, Algorithm database
Solver (manual input or via camera). List of solving algorithms.
A big database of all possible sequence for each category (PLL, OLL, F2L...). Support for 'favorite' flag, adding new category and new algorithms.
Simply a big page with all solving algorithms, clear and well-designed. Must have.

PC

  • TNoodle
    • Official WCA's scrambler, showing final cube state. Include a very nice timer application. Download TNoodle: 
    git clone https://github.com/cubing/tnoodle.git

./tmt graph --description                 # To get a list of available target
    Timer
    Timer application is only available up to v0.8.7.
    git checkout v0.8.7
./tmt make dist timer
sudo cp -r timer/dist /usr/local/bin/tnoodle-timer
chromium-browser /usr/local/bin/tnoodle-timer/tnt.html           # To start the javascript timer

    In old version, timer is available as a .jar file. For instance: 

    git checkout v0.7.14
vi tmt
# Comment line with
#                args += [ '-Werror' ]
./tmt make dist timer
java -jar timer/dist/TNoodleTimer.jar 
# Then visit http://127.0.0.1:8080/tnt/ or http://127.0.1.1:8080/tnt/ (or possibly port 2014)
    • Data for the javascript tnoodle-timer is stored in chromium local storage:
    On the disk
    ~/.config/chromium/Default/Local Storage
  __0.localstorage
  __0.localstorage-journal
  chrome-extension_pafkbggdmjlpgkdkcbjmhmfcdpncadgh_0.localstorage
  chrome-extension_pafkbggdmjlpgkdkcbjmhmfcdpncadgh_0.localstorage-journal
    Or better, in chromium, open developer tools by pressing F12,then
    • Export timing data — Go to Console tab, then type localStorage.sessions to get the content of the array, and save the results.
    • Import timing data — Go tot Console tab, then type localStorage.sessions="XXX" where the XXX is replaced by the result saved previously, but with all double-quotes escaped. These can be escaped for instance with
    sed 's/"/\\"/g" sessions.txt > sessions-escaped.txt
    Sessions data is also available in the Ressources tab, but long values get truncated, and hence this is not suitable method for import / export.
    • To install tnt in lighttpd (example on lacie-cloudbox):
    vi /etc/lighttpd/lighttpd.conf
    Add the lines
    ## Added for rubik's WCA official scrambler / timer
alias.url += ("/tnt" => "/opt/local/tnoodle-timer/tnt.html" )
    Copy all files to /opt/local/tnoodle-timer/
    Then open browser at http://lacie-cloudbox/tnt/ (Firefox or chromium works best it seems, Opera only works via file: access)
    Other TNoodle apps
    • BLD
    • scrambler
  • qqtimer (the most used timer it seems) (qqTimer on GitHub)

Notation

  • Cube rotation x, same as R but whole cube
  • Cube rotation y, same as U but whole cube
  • Cube rotation z, same as F but whole cube

Sequences

We call a move a permutation on the cube that can be done in a single movement. This can be the rotation of a face by 90° or 180°, but also rotation of a middle layer, two layers, or the whole cube. Each move has a dedicated letter, with a prime indicating the reverse movement.

A sequence is a small serie of moves that is frequently used to build up more complete algorithms. Typically these sequences are done very rapidly. Fast algorithms are those that link several sequences with an easy transition (no re-gripping, cube rotation, etc).

The inverse of a sequence is the sequence that cancel the effect of that sequence. We use prime to denote that sequence.

A mirror sequence if the L-R symmetric sequence (i.e. F changes to F', R changes to L', etc)

Sledgehammer
  • Right: F R' F' R (prime: R' F R F')
  • Left: F' L F L' (prime: L F' L' F)
Note: If we do this sequence with the right-hand (after cube rotation y'), we get y' R' F R F, which is the same as Right prime.
Overshoot
  • U' R' F R
Sexy move
  • Direct: R U R' U' (prime: U R U' R')

Tutorials

F2L

Source: Tutoriel : Résoudre les F2L intuitivement

The principle is to always fall back in one of the 4 basic cases. A basic case is one that requires only 3 moves to solve:

  • Case /R1/: R U' R' and case /L1/: L' U L (mirror)
Pair next to each other, horizontal and left (right) of target slot.
  • Case /R2/: R U R' and case /L2/: L' U' L (mirror)
Corner above target slot, edge on UB. Corner white sticker facing right (left), front sticker same as edge up sticker.


Notes:

  • Always put the corner above the slot, and solve from the right side first, then switch to left if necessary.
  • In algorithm below, whitespaces indicate that we reached a basic case.
  • We can always replace U2 R U' R' with U sledgeR'.
  • Case solve are coded for fast reference. (R2, BR) means we want to get a basic case /R2/ by bringing the corner above BR corner. (R2, BR, rot) means we aim at obtaining a /R2/ case by using the BR corner, but this time with rotation of the corner; this means that the corner is moved above the BR corner not using a U move (followed by R ... R' that would preserve orientation of the corner), but with a R moves that changes orientation of the edge. So rot indicates that the solves change the F2L family.

There are 3 F2L families: sticker UP, sticker FRONT, and sticker RIGHT.

White sticker UP

  • Edge on 2L:
  • (2L1) Case 1, edge wrong (matching corner color): we simply get the pair out, then reinsert R U2' R' y U2 (L' U L) (or my variant: R U2' R' U' F R' F' R')
  • (2L2) Case 2, edge correct (not matching corner): sexy sexy sexy.
  • Edge on LL, not touching: we get a basic base by (i) bring edge to its color, (ii) raise empty slot, (iii) bring corner above the edge, then (iv) turn back slot. All cases below are identical.
  • (LLBU1) Edge on BU, case 1: U R U2' R' R' F R F'
  • (LLBU2) Edge on BU, case 2: y U2' L' U' L L F' L' F
  • (LLLU1) Edge on LU, case 1: U2 R U R' R' F R F'
  • (LLLU2) Edge on LU, case 2: y U' L' U2 L L F' L' F
  • Edge on LL, touching:
  • (LLRU1) Edge on RU, side color not matching (R2, BR, rot): create a /R2/ case by using BR corner with R move, and U2, R U2' R' U' (R U R').
  • (LLRU2) Edge on RU, side color matching (LLBU2, BR): fall-back to case (LLBU1) using BR corner with U' then R, U' R U' R' U' y L' U' L (L F' L' F).
  • (LLFU1) Edge on FU, side color not matching (L2, FL, rot): create a /L2/ case by using BL corner with y L' move, and U2, y L' U2 L U (L' U' L) y'.
  • (LLFU2) Edge on FU, side color matching (LLLU1, FL): idem, fall-back using BL corner (with y U then L' ), y U L' U L U y' R U R' (R' F R F').

White sticker FRONT

  • Edge on 2LL:
  • Case 1, edge correct (R1, BR): goal is to get a /R1/ using BR corner, U' R U' R' U2 R U' R'.
  • Case 2, edge wrong (L2, BR): goal is to get a /L2/ using BR corner, U' R U R' U y L' U' L.
  • Edge on LL, non-adjacent
  • Case 1, same U color, edge BU (R1, BR): Goal is to get a /R1/ using BR corner, U' R U R' U2 R U' R'
Idem for edge LU (R1, BR): U' R U2 R' U2 R U' R'
  • Case 2, different U color, edge BU (L2, BR): Because U color are different, goal is to get a /L2/ case here using BR corner: y U L' U' L U' L' U' L (or U' R U' R' U y L' U' L).
For edge LU, this time we directly have a /L2/ (L2): y L' U' L
  • Edge on LL, adjacent on RU
  • Case 1, same U color (R1): we have directly a basic case /R1/, U R U' R'.
  • Case 2, different U color (L2, BR): so we want to get a /L2/, using BR corner: U' R U2 R' U y L' U' L.
  • Edge on LL, adjacent on FU
  • Case 1, same U color (R2, FL, rot): we use FL corner to get a /R2/ : y L' U L U2' y' R U R'
  • Case 2, different U color (R2, FL): we use FL corner to get a /L2/: y U L' U L U' L' U' L

White sticker RIGHT

  • Edge on 2LL 2LL:
  • Case 1, edge correct (L1, FL): mirror of above, get a /L1/ using FL corner, and U then L' move: y U L' U L U2' L' U L y'.
  • Case 2, edge wrong (R2, FL): mirror of above, get a /R2/ case using FL corner, and U then L' move: y U L' U' L y' U' R U R'
  • Edge on LL, non-adjacent
  • Case 1, same U color, edge BU (L1, FL): Here the best is to solve FR then send it to BR y' U R' U' R U' U' R' U R y (alt: y' U R' U' R U' y F R' F' R or y U L' U' L U' L F' L' F y').
idem for edge LU (L1, FL): y' U R' U2 R U' U' R' U R y (alt: y U L' U2 L U' L F' L' F y').
  • Case 2, different U color, edge LU (R2, BR): we need to shift our edge by a single U move: U' R U R' U R U R'
For edge BU (R2): this time we directly get a /R2/: R U R'
  • Edge on LL, adjacent on RU
  • Case 1, same U color (L2, BR, rot): we get a /L2/ case using BR corner and R U' move, R U' R' U2 y L' U' L y'
  • Case 2, different U color (R2, BR): we get a /R2/ case using BR corner and U' R move, U' R U' R' U R U R'
  • Edge on LL, adjacent on FU
  • Case 1, same U color (L1): we directly have a basic case /L1/, L' U L
  • Case 2, different U color (R2, FL): so we want to get a /R2/ case. We can with FL corner, y' U R' U2 R y U' R U R' (or y U L' U2 L U' y' R U R')

Some shortcuts

  • Corner FBR, white sticker on BOTTOM:
Known case from beginner method. Bring matching edge on UP face, on its matching face, then
  • If matching face FRONT: U R U' R' F R' F' R (this move is called le belge)
  • If matching face RIGHT: y U' L' U L F' L F L'

For other sticker positon, we use the sexy move variants:

  • If edge UP face is FRONT face → use either double sexy (if white RIGHT) or sexy' (if white FRONT).
  • If edge UP face is RIGHT face → do a y, then use double sexyL (if white LEFT) or sexyL' (if white FRONT).

Sexysexy.png Solved with sexy sexy

SexyLsexyL.png Solved with y sexyL sexyL y'

Sexypsexyp.png Solved with sexy' sexy'

SexyLpsexyLp.png Solved with y sexyL' sexyL' y'


Otherwise, an alternative solution is:

  • Corner FBR, white sticker on FRONT:
If corner RIGHT sticker matches edge UP sticker:
  • Move edge to RIGHT on its matching face, then R U' R' R' F R F'
(better than y L' U2 L y' R U2 R').
Else, corner BOTTOM sticker matches edge UP sticker:
  • Move edge to BACK, then R U' R' y L' U' L y'
  • Corner FBR, white sticker on RIGHT:
If corner FRONT sticker matches edge UP sticker:
  • move edge to LEFT, then L' U L y' R U R')
Else, corner BOTTOM sticker matches edge UP sticker:
  • Move edge to FRONT on its matching face, then R U R' U' F R' F' R

Fridrich simplified

Source: Rubik's cube : Méthode intermédiaire (fridrich simplifiée)

4 steps:

  • Cross
  • F2L
  • 2-look OLL
  • 2-look PLL

For F2L, see tutorial above.

For 2-look OLL, first do the cross:

  • Line shape: F sexy F' (F' with the thumb)
  • L shape: f sexy f' (f' with the thumb)
  • no shape: do 1st then 2nd algorithm

Then we do one of the 7 OLL "cross" algorithms. The cases are denoted by the position of yellow sticker for each corner, starting from FL, the FR, BR and BL corner. So UFRB means the yellow sticker facing upward for the left-front corner, facing front for the right-front corner, facing right for the right-back corner, and facing back for the left-back corner.

  • UFRB: R U R' U R U2 R'
  • FRUL: R U2 R' U' R U' R' (inverse of UFRB)
  • FFUU: R2 D R' U2 R D' R' U2 R' (D and D' ideally by pulling then pushing with left-hand finger)
  • LRUU: x' R U R' D R U' R' D' (idem) (x' R → l, so l U R' D R U' R' D') (or variant UFBR: l' U' L U R U' r' F)
  • URUB: x' R U' R' D R U R' D' (idem) (x' R → l, so l U' R' D R U R' D')
  • FFBB: F sexy sexy sexy F'
  • LFBL: R U2 R2' U' R2 U' R2 U2 R

For 2-look PLL, like for the 2-OLL, we first do the cross, then the corners. For the cross, turn the U face until 1 edge is good, and place it at F slot, and look how the other edges must be permuted.

  • All edges are ok: congratulations ;-)
  • clockwise: R' U R' U' R' U' R' U R U R2' (do R' U R' U' with right index under BRD corner, then R' U' R' U with right index next to FRD corner)
  • anti-clockwise: R2' U' R' U' R U R U R U' R
  • 2 edge ok: do either of algorithm above, and retry.

Then look at the corners. If one corner is good, turn the cube such that it is at FL slot, and look how the other corners must be permuted

  • 1 good corner (FL), clockwise: x R' U R' D2 R U' R' D2 R2 or l' U R' D2 R U' R' D2 R2 (using x R' → l')
  • 1 good corner (FL), anti-clockwise: x R2' D2 R U R' D2 R U' R l' R' D2 R U R' D2 R U' R (best grip: left thumb on D face, right thumb on F face, left ring finger to prepare the D2 / D2, right index to prepare the U.
  • no good corner: do either of algorithm above, then you will have a good corner

Algorithms

PLL - swap 2 edges
  • R U R' U R U2 R' U

Solution

We use notations from https://github.com/chrishunt/rubiks-cube:

  • R, means turn Right face clockwise
  • R' or r, means turn Right face counter-clockwise
  • R2, means turn Right face twice.
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