Rubik's cube: Difference between revisions

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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
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: <code>x R' U R' D2 R U' R' D2 R2</code> or <code>l' U R' D2 R U' R' D2 R2</code> (using <code>x R'</code> &rarr; <code>l'</code>)
* 1 good corner (FL), clockwise: <code>x R' U R' D2 R U' R' D2 R2</code> or <code>l' U R' D2 R U' R' D2 R2</code> (using <code>x R'</code> &rarr; <code>l'</code>). My old fingertrick was {{blue|left thumb on F center, left index/middle/ring fingers on back, right thumb on U face, right index under RBD corner. First U done with right index, then D2 done with left ring+middle or left little+ring, then U' done with right thumb, like for the sledgehammer}}. This fingertrick is not adviced, instead train on using the {{blue|left index to do the U' move}} [https://www.youtube.com/watch?v=-YrtxKcg7m0].
* 1 good corner (FL), anti-clockwise: <code>x R2' D2 R U R' D2 R U' R</code> <code>l' R' D2 R U R' D2 R U' R</code> ({{blue|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}}.
* 1 good corner (FL), anti-clockwise: <code>x R2' D2 R U R' D2 R U' R</code> <code>l' R' D2 R U R' D2 R U' R</code> ({{blue|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
* no good corner: do either of algorithm above, then you will have a good corner

Revision as of 20:39, 9 January 2015

This page is a stub.

Links

Official
Guides & Wiki
Buy guides, solutions, (new) how to improve...
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
Insert a connected pair in wrong slot to get out a corner with white sticker to prepare next slot.
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

More apps can be found at [2].

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. Only drawback is that times are saved in the browser local storage. 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)
  • CCT (CALCubeTimer), in java, from here (discontinued, use Prisma Puzzle Timer instead)
    • Show scramble view, optimal cross solve algo...
  • Prisma Puzzle Timer (PPT), in java, from here (include graphs, history...]
    • Including (partial) scramble view, graphs, tips with optimal cross algo...

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

Acronyms:

LH
Left-hand
RH
Right-hand
SH
Sledgehammer

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)

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

Tutorials

F2L

See Rubik F2L.

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' (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 (right thumb on B face, right index on FRD corner, ready for 1st U, then R U' R with RH, U' with right thumb)
  • 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'). My old fingertrick was left thumb on F center, left index/middle/ring fingers on back, right thumb on U face, right index under RBD corner. First U done with right index, then D2 done with left ring+middle or left little+ring, then U' done with right thumb, like for the sledgehammer. This fingertrick is not adviced, instead train on using the left index to do the U' move [3].
  • 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

Finger Tricks

  • D2 move
Use the ring and major finger. To work well, hold the cube with index and thumb such that ring and major hits the left (or right) side of the D face almost vertically. For instance, using the left hand, the index must hold both the LBU corner and LB edge, and possibly a bit the center back face and BU edge. See this video.

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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