[HN Gopher] S.A.R.C.A.S.M: Slightly Annoying Rubik's Cube Automa...
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S.A.R.C.A.S.M: Slightly Annoying Rubik's Cube Automatic Solving
Machine
Author : chris_overseas
Score : 260 points
Date : 2025-10-31 23:03 UTC (23 hours ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| derac wrote:
| The aesthetics of this are great. Nice job.
|
| Demo: https://youtube.com/shorts/Xer4mPZZH8E
| boneitis wrote:
| This is absolutely the most charming thing I've seen in a hot
| minute.
|
| For anyone also thoroughly enchanted like me, there is an
| additional, longer demo:
|
| https://www.youtube.com/watch?v=WV52RtuWXk0
|
| Living in software land, I do wonder how hard is the
| undertaking to build one of my own.
|
| As a hobbyist cuber, this project reeks of icebreaking
| potential for the rest of the times I'm not actively solving --
| leave it on my desk next to a cube... random coworker walks by,
| sees and grabs the cube, shuffles it, and chucks it into the
| SARCASM machine, enjoys a minute of novelty, ????, profit!
| wilg wrote:
| It's a cool project, but also they're really underselling the
| amount of work put in to make it annoying.
| chris_overseas wrote:
| There's a lot more detail describing the project in a couple of
| forum posts here:
| https://forum.pjrc.com/index.php?threads/sarcasm-an-over-eng...
| shmeeed wrote:
| This is a hot contender for the Most Awesome Thing I Saw On The
| Internet In 2025. Incredible work!
| stavros wrote:
| This is fantastic, how did it not get confused by the blue logo
| on the cube in the video?
| trenchpilgrim wrote:
| Western cubes always have white opposite yellow. Japanese cubes
| always have white opposite blue. (The center piece on each side
| can be considered "fixed" relative to all moves.)
| stavros wrote:
| Ahh right, I forgot the center piece defines the face color,
| thanks.
| nneonneo wrote:
| Related - there's a Guinness record for the fastest Rubik's cube
| solving robot; it stands at 103 _milliseconds_ :
|
| https://www.youtube.com/shorts/ue2gZ2vxs48
|
| https://engineering.purdue.edu/ECE/News/2025/purdue-ece-stud...
| hammock wrote:
| Robotic solver is more of a physical problem than a mental one.
| A photo of the cube from top and bottom corners and you can
| solve it in a nanosecond
| teiferer wrote:
| First, you still need to optimize the solution to fit the
| constraints of mechanical solving. It needs to be as few
| moves as possible, some of them are parallelizable, etc. Not
| a trivial problem.
|
| Second, nanosecond? You know that a GHz CPU does a single
| clock tick in one nanosecond, right?
| rossant wrote:
| Maybe there's a new instruction we don't know about in
| modern CPUs, like RUBIK_SOLVE or something.
| SwiftyBug wrote:
| I mean, we've had RUN_DOOM for many years now, so why
| not?
| Tempest1981 wrote:
| They probably meant millisecond
| adrianN wrote:
| I wonder how many cubes they exploded in the making of that
| robot
| hermitcrab wrote:
| Impressive and a bit mad.
| xiaoyu2006 wrote:
| I think you built a rubik cube solving machine just to show-case
| your acronym ;-) Super cool work.
| teunlao wrote:
| SARCASM: the only acronym worth building hardware for
| noman-land wrote:
| I want an automatic scrambling machine, not an automatic solving
| machine. Two cubes. While you're solving one, the other one is
| being scrambled. Cubers spend _way_ more time scrambling than
| solving. Scrambling is the annoying part that needs automating.
| dullcrisp wrote:
| Can't you just run the solving machine in reverse?
| noman-land wrote:
| You can but it doesn't need to be smart at all. It doesn't
| need cameras. It's a much simpler machine.
| boneitis wrote:
| Funny enough, that (e: the shuffle function mentioned in
| original thread post, just realized my awkward comment
| placement) sounds like a very reasonable stretch
| goal/feature add-on, although I'm not sure this particular
| machine could shuffle quickly enough for speedcuber types.
| rplnt wrote:
| It needs to be somewhat smart, if you want to track your
| scrambles and times. But yes, it doesn't need cameras if it
| trusts you.
| schiffern wrote:
| Yeah, it's just a software change to the existing machine. If
| you generate a target scrambled state it's literally the
| solver algorithm in reverse too.
|
| It would be neat if it offered to scramble when you insert an
| already solved cube (demoed in the video), and maybe have
| options for the amount of randomness.
|
| Is there an unbiased scrambling (or random generation)
| algorithm, or is it enough to just generate N random moves?
| schiffern wrote:
| To answer my own question, competitive cubing uses unbiased
| randomization algorithms.[0] To minimize scrambling time,
| it could fairly generate a random configuration and then
| optimally scramble the cube in ~18 moves.[1]
|
| TL;DR fair scrambling is exactly as fast (same throughout)
| as solving random cubes! Neat.
|
| [0] https://www.cubelelo.com/blogs/cubing/how-to-scramble-
| a-rubi...
|
| [1] https://en.wikipedia.org/wiki/Optimal_solutions_for_the
| _Rubi...
| LVB wrote:
| I'm completely not in this space but your comment had me
| wondering: are there digital cube faces? That is, a real
| physical cube but with faces that can instantly be set to a
| given color?
| sunnybeetroot wrote:
| This is a great question! Doesn't seem like it'd be hard to
| make if it doesn't already exist
| apple1417 wrote:
| They exist, but one of the problems is they're not
| particularly good cubes. While it might help you learn the
| basics, not being able to handle it like a speedcube means
| they're probably not going to help you get faster.
|
| https://m.youtube.com/watch?v=l-TWH5W-1fw
|
| https://exmarscube.com/product/ex-mars-ai-robot-cube/
|
| That being said, while looking up those links, I found out
| that, since I got out of the hobby, smart cubes have become a
| thing, and are made by real speedcube manufacturers.
|
| https://www.gancube.com/products/gan-356-i-carry-smart-
| magic...
|
| This is an easier problem to solve. I'm not sure if you have
| to solve it first or if it can identify pieces on power up,
| but after that it's just tracking rotations, which can be
| done from the (fixed position) centres alone. But if an
| actual speedcube manufacturer can already fit those
| electronics in without comprising performance, I can't
| imagine it's that much harder to fit some addressable LEDs on
| some slip-ring-esque connections. Must just not be much of a
| market.
| alejo wrote:
| This is in my mind the hardest part as well.
|
| I can solve the cube with the regular "easy" 3-layer approach,
| but I'd like to solve it faster.
|
| The issue is that the techniques for fast solving require to
| learn many different patterns to get to the right solution
| fast.
|
| I don't know really how ppl that solve it fast accomplish
| getting to that level, but to me it would be amazing if i could
| just set the cube in know scrambled states that let me practice
| and memorize specific algorithms repeatedly until I learn them.
|
| The problem is that I don't know enough yet to distinguish
| which are those initial states, let alone setting the cube in
| that state, so something that could set it up for me to
| practice would be amazing
| 0x264 wrote:
| > I don't know really how ppl that solve it fast accomplish
| getting to that level
|
| Just like everything else in life, they do it really slow and
| with lots and lots and lots of errors at first, but (and this
| is where the magic happens) keep doing it, training hours a
| day or their entire week ends, for years.
| rplnt wrote:
| At least until a certain level, scrambling (according to a
| given "algorithm") is a good way to practice moves. It
| shouldn't take much longer than a solution either, you are not
| solving the cube in under 30 moves. And if you don't care about
| the scramble it's even faster. So I don't think the "way more
| time" is entirely accurate. It may feel like it though.
| optimiz3 wrote:
| Impressive work. Curious to how many hours of labor what the
| development path was. Several man-years possibly?
| dugidugout wrote:
| The screen ui aestetic and audio (specifically the dubbing)
| remind me of the silver case series, may be a total reach, nice
| touches none the less!
|
| https://en.wikipedia.org/wiki/The_Silver_Case
| watson wrote:
| This is one of the best arguments for purchasing a 3D printer
| metalman wrote:
| whats the point? rubicubes are for hoomans got one when I was 12,
| solved the next day, couldn't tell you how,got better, got fast,
| got bored, never touched one again. but this much....not knowing
| and solving as an unconsious process is likely to be the
| advantage or to put it another way, knowing is limmiting and
| constrains doing. hooman thing.right
| vindar79 wrote:
| Hi all. I just found this thread. I'm the creator of SARCASM.
| Thanks to the OP for sharing. I spent many hours on this build
| but it was a lot of fun. I'm happy to see that others are
| enjoying it also :-)
|
| If you're interested in the technical side, I wrote detailed
| posts on the hardware and software on the Teensy forum:
| https://forum.pjrc.com/index.php?threads/sarcasm-an-over-eng...
| ewalk153 wrote:
| Can you post the STL files for the shell and Arms?
|
| Great project.
| vindar79 wrote:
| Sure. I will add them on github later today. The repo is
| currently in a very messy state. I would like to clean it and
| provide detailled assembly steps but I have to much work
| currently. Hopefully I can do this in a couple of months.
| vindar79 wrote:
| Done. Added stl files to the repo.
| scrollaway wrote:
| > _I 'm the creator of SARCASM._
|
| Glad I'm not the only one who sometimes justifies spending time
| on project purely because of the name I can give to them.
| vindar79 wrote:
| hehe, it was indeed a major motivation :-)
| ramses0 wrote:
| This makes me want to teleport it back to the 1920s, enclose it
| in glass and charge people a nickel to use it! You'd be rich!
| hermitcrab wrote:
| Very cool. I remember being the first kid at school to have a
| Rubiks cube, in the 70s (I read about it in Omni magazine). I
| had no idea how to solve it. I sent off for a booklet about
| solving it. I got back a booklet about group theory, far beyond
| my teenage brain.
| ugh123 wrote:
| I think this is an amazing all around build combining the
| physical mechanics for solving (a relatively understood problem
| in rubik's robot solving scene) but along with the graphics
| integration and some real personality from the bot avatar that
| gave me quite a few laughs. Well done!
| shmeeed wrote:
| I love how you approached the problem and perfectioned the
| "product" in all aspects. There's so many playful details that
| could easily go unnoticed! You're impressively resourceful, and
| one can tell this was a work of love.
|
| I wish I could buy something like it as a DIY set, just to own
| it, admire it, show it to people, and have everybody be in awe
| of your work. What a time to be alive that stuff like this is
| in reach of a sufficiently dedicated hobbyist!
| aEJ04Izw5HYm wrote:
| The personality of creator really shines through in the software.
| Douglas Adams would be pleased, I hope loads of hackers will be
| inspired to make more 'Adamsian' robots.
| moffkalast wrote:
| I'm looking forward to more genuine people personalities from
| Unsirious Cybernetics.
| zkmon wrote:
| Solving a cube has two parts, determining the moves and making
| the moves. For humans these two activities happen mostly in
| parallel. For robots, moves were already determined before the
| start. So the time taken is merely all about speed of move
| making.
| klaudioz wrote:
| Cool!!, I've created this one 16 years ago:
| https://www.youtube.com/watch?v=bkWLQZgi9uE
|
| I can see very similar movements this robot is doing compared to
| my old robot. I really like the screen outputs of it.
| cellular wrote:
| This looks like a good place to ask HN:
|
| I've started with a solved cube, then turned 2 sides sharing an
| edge, alternatively (same direction) expecting the cube to get
| messed up but then returning to its solved state.
|
| It never got solved! Maybe i didn't do it enough (i did it
| hundreds of times i think). Has anyone got an explanation?
| rokicki wrote:
| It should take 105 repetitions:
|
| https://alpha.twizzle.net/explore/?alg=%28U+R%29105
|
| Unless by "same direction" you mean "opposite direction", in
| which case 63 works:
|
| https://alpha.twizzle.net/explore/?alg=%28U+R%27%2963
| JonathanMerklin wrote:
| The cyclic group generated by e.g. RU has order 105 (so 210
| total turns or 105 of each side, alternated). If you have some
| math know-how, check out [1]. If you don't, take my word for
| it: when I was a teenager playing around with cubes, I once had
| a similar experience trying to do the same thing you did - when
| I went relatively quickly it never returned to the solved
| state, but when I was very deliberate about each turn, I got
| the 105 result (not by counting back then, but by rough time
| estimate given the figure I just looked up). Both you and I
| probably accidentally threw in one or more double-turns (like a
| U2) in there, or undercounted and gave up well before the cycle
| had completed (I, too, had thought I'd made "hundreds" of
| moves).
|
| [1] https://faculty.etsu.edu/gardnerr/4127/algebra-club/rubik-
| ta... - slide 41
| branon wrote:
| Pedantic pet peeve: it'd be S.A.R.C.A.S.M. or SARCASM but not
| S.A.R.C.A.S.M
|
| You are missing the last full stop, unless your project is
| actually meant to be called "S.A.R.C.A.S. M"
|
| An initialism either uses full stops after all letters or none of
| them.
| slug wrote:
| I built a cubotino a few years ago, similar mechanism, see
| https://github.com/AndreaFavero71/cubotino
|
| Uses a rpi 2 w, works well, can solve and scramble 3x3x3 cubes,
| using just 2 servo motors.
| bolangi wrote:
| So does that make the developer a sarcasmaholic?
|
| https://www.youtube.com/watch?v=JcOfFeKXcd4
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(page generated 2025-11-01 23:01 UTC)