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S.A.R.C.A.S.M: Slightly Annoying Rubik's Cube Automatic Solving Machine

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Re: S.A.R.C.A.S.M: Slightly Annoying Rubik's Cube Automatic Solving Machine

#41

Post by vindar79 »

ewalk153 wrote: post #35
vindar79 wrote: post #34

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...

Can you post the STL files for the shell and Arms? Great project.

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.

Re: S.A.R.C.A.S.M: Slightly Annoying Rubik's Cube Automatic Solving Machine

#42

Post by vindar79 »

scrollaway wrote: post #36
vindar79 wrote: post #34

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...

> 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.

hehe, it was indeed a major motivation :-)

Re: S.A.R.C.A.S.M: Slightly Annoying Rubik's Cube Automatic Solving Machine

#43

Post by ramses0 »

vindar79 wrote: post #34

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...

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!

Re: S.A.R.C.A.S.M: Slightly Annoying Rubik's Cube Automatic Solving Machine

#45

Post by cellular »

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?

Re: S.A.R.C.A.S.M: Slightly Annoying Rubik's Cube Automatic Solving Machine

#46

Post by branon »

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.

Re: S.A.R.C.A.S.M: Slightly Annoying Rubik's Cube Automatic Solving Machine

#47

Post by Tempest1981 »

teiferer wrote: post #31
hammock wrote: post #10

Earlier quoted context omitted.

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

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?

They probably meant millisecond

Re: S.A.R.C.A.S.M: Slightly Annoying Rubik's Cube Automatic Solving Machine

#48

Post by rokicki »

cellular wrote: post #45

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?

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

Re: S.A.R.C.A.S.M: Slightly Annoying Rubik's Cube Automatic Solving Machine

#50

Post by JonathanMerklin »

cellular wrote: post #45

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?

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

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