Puzzled 2: Curvy Rhombohedron Skewb

Showing posts with label Curvy Rhombohedron Skewb. Show all posts

Thursday, October 6, 2022

Old Treasures and Blasts From The Past

I posted this Skewb Collection a couple days ago on Craigslist.

Dino Skewb, Ultimate Skewb, Curvy Rhombohedron, Squished Skewb.

Apple//e Software

Calendar Maker was a program I wrote to print out calendars on a dot matrix printer for Dad. He was really into birhtday calendars.

I had a program published on Softdisk! Loose Change. They totally reworked the graphics and I didn't even feel like it was mine any more, but the idea was mine for sure. When I taught algebra at FLCS we had some word problems that gave a given amount of money made from an known number of coins. The object was to use two equations with two unknowns to figure out how many of each coin there is. I had left a problem on the board one day and after school Rory, when he was 12 give or take, quickly figured it out in his head, no algebra required. I started giving him problems like this for fun and programmed a computer game for him based on these problems.

IO Silver was a game we liked published by Beagle Bros. Software in 1984. All I remember is using 4 keys on the keyboard to make the little guy run around the screen collecting things.

The Rory and Raymond disks were... hmmm... I seem to recall making a game disk for each boy. When you booted it up it ran a math practice thing or something that they had to pass in order to get to the fun games. I think that is how it worked.

Loderunner. Ahhh. Loderunner. How many hours I spent playing the 150 levels and making levels of my own. A quick online search uncovered an online version so I can play the Apple //e version on my Chromebook! Lode Runner Web Game

Dino Eggs. One of the games that came on Softdisk. I think we played it quite a bit but I have no recollection of the details. Good news. Some guy made a video on YouTube. Dino Eggs And in the description there is a comment by the original creator and a link to his story about making the game.

Super Boulder Dash. Did it come from Softdisk too? Don't recall. It was fun and engaging enough to have and keep but I do not remember it either. Again, it can be found on YouTube.

Championship Lode Runner. This added another 50 levels to the original 150. I was so pleased that I could pass them all I documented it on the label.

AppleWorks 4. Oh oh oh. AppleWorks on the //e. Fond memories.

Math Blaster. This was the best version of Math Blaster in my opinion. The Mac version did not appeal to me at all. I loved the Apple //e Math Blaster game. Rory was the Math Blaster Champion.

The Beagle Bros. !!! I had quite a collection of their software for the Apple //e.

I learned about Fractals on an Apple //e. Oh yeah. Green monitor. Relatively slow processor. I would start one before I went home for the day and hope it would be finished by the morning. But I was fascinated by the math behind the graphics.

If I remember correctly Myst was for the //e, DuelTris was for the Apple 2gs, and obviously the book was written for Mac users. I think I completed Myst. DuelTris was a fun 2-player form of Tetris. And the book was very influential in teaching me how to take advantage of the Mac word processor instead of trying to type on the computer as if it was simply a typewriter.

In 2003 the boys and I made up a new Frisbee Golf game on our home course of 15 "holes". We called them holes even though they were really trees, rocks, a ditch, and a swingset. Over the years we played a lot of Frisbee Golf. And for the most part we used normal Frisbees, not the new fangled disc golf discs. Sometimes we played each person against the others. Usually we played teams. Sometimes one team against another, but usually the team was all of us. We were seeing how low a score we could get. At one point in our history of Frisbee Golf games we played Speed Frisbee. I'd time the game on my wristwatch and we would play as a team, usually Rory and I throwing and Raymond blocking to keep the Frisbees as close to the holes as possible. We would combine the times and scores to get the final score. I kept track in a little notebook. But in 2003 we made up a new game. How many throws does it take to get all ones? Our bests:

Ro & I: 66 on September 6, 2003

Rory, Robert & I: 54 on October 21, 2003

Raymond & I: 62 on October 8, 2004

Rory & Raymond: 38 on August 4, 2007

As far as I know we haven't tried since.

Monday, February 17, 2014

Curvy Rhombohedron Skewb

The first couple solves I just started putting pieces together that looked like they needed to be put together. Eventually a 3-cycle or a twist or two needed to be done to finish up and I drew from my Skewb Family Arsenal of Algorithms (I just made that up).

But then Kevin asked how I solve the Skewb, so I got out the Skewb Cube and solved it. Then the Tetrahedral Skewb. Then the Squished Skewb. Then I intentionally tried to use the same strategy to solve the Curvy Rhombo Skewb.

Documented Scramble #1: DNF
After getting the first 8 pieces solved, leaving only 6 to go, the thing still looked scrambled! After using a setup move and the 3-cycle to place 2 of the 6 pieces, and not being able to see how to undo the simple setup move, I decided that although it is possible to solve in the same way, a more intuitive approach would be better.

Documented Scramble #2:
After solving the yellow layer, including the green and purple triangle center pieces, one twist of the black layer was needed to solve the 3 remaining triangle center pieces. That left the 3 remaining edges out of place and the remaining corner twisted. After using Double-EPS to place the edges instead of the pure 3-cycle, both of the diagonally opposite corner pieces needed twisted. I don't think it is possible to twist them together, so I twisted each one with a triangle using an algorithm that hadn't been used in any of the previous posts' solves. I will not even attempt to type it out.

So it turns out I not only demonstrated the algorithm. I also showed what happens when unexpected results happen, and one way to solve mysteries! :D

Documented Scramble #3:
Very difficult to get the yellow layer this time. The first several times I tried it this way it seemed almost trivial to get a layer solved. But this time, either it was a different scramble, or my mind wasn't in sync with the puzzle as before. This can be a problem when solving intuitively rather than with a systematic strategy. I ended up using Triple-EPS a couple times to swap pieces into place on the yellow layer.

After solving most of the black layer as described in #2, once again I ended up with the 2 small corners twisted. Two lessons to learn. First, if I would use the same steps as I do with other Skewb puzzles, I wouldn't have this problem at the end. So is it worth it to work through a more visually challenging solve at the beginning to make the endgame go more smoothly?

Secondly, it dawned on me that one conclusion I made in #2 above is incorrect. I said "I don't think it is possible to twist them together," because one is in the corner role and the other in the center role (thinking of the Tetrahedral Skewb). But what did I learn in the video above? I can twist 1 corner and 3 triangles, in the unshapeshifted puzzle, and 2 of the triangles are centers! So I can twist a corner and a center together! Yay!

In conclusion... well, is it ever really concluded? Let's just say that after several more solves I have decided that at this point I rather like solving it using the same basic approach taken with the other Skewb Family puzzles. That is, get the 2 small corners and the 6 triangles first. This only takes a few simple twists. Maybe 1 EPS. So with half a dozen twists or less more than half the puzzle is solved! Then 3-cycle the 6 big pieces home.

If a corner needs twisted without disturbing triangles, up twist down replace up twist-the-other-way down go-back works well and is pretty simple. Let's see.

Bottom line though, with this puzzle, as with any puzzle, there is no right or wrong, easy or hard, better or worse, way to solve it. I may decide on a favorite way to solve it tonight, but 6 months from now pick it up and take a whole different approach. I suppose I should demonstrate the Preferred Method applied to this one, so

Documented Scramble #4:

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Rubik's Cube Books

I got my first Rubik's Cube in the early nineteen eighties. The only way I could solve it was to take it apart and put it back together solved. Until, that is, I got some little books that explained sequences of moves that could be used to put pieces where you want them without messing up what was already in place.

The Simple Solution To Rubik's Cube
by James G. Nourse
Notes on Rubik's Magic Cube
by David Singmaster
Solve That Crazy, Mixed-up Cube Puzzle
by Don Frederick.

I think I put together my own strategy using bits and pieces gleaned from all three books. Eventually I lost interest and forgot how to complete the cube, forgot I had those books, and lost track of the cubes.

Mark Jeays' Working Corner Method

http://jeays.net/rubiks.htm

In 2007 my interest in Rubik's Cube was rekindled when I watched the movie The Pursuit of Happyness. Marae found my 1980s cube for me and I tried to solve it. Huh-uh. I could do part of it, but not the last layer. Looking online I found various tutorials. Mark Jeays included YouTube videos with his Solution 2. This method worked for me and although I no longer use it in its entirety, nor could I, as I have forgotten the yellow edges sequences, I still find the basic working corner technique helpful, and use a slightly modified version of his corner twisting technique at times.

In the summer of 2014 we packed 30 or so puzzles and flew to visit Raymond and Fam in the Czech Republic. Breann, who had learned this method and no other, made some comment about bubururu or something like that, and it piqued my curiosity. What were those algorithms, and how similar are they to the EPS technique I use now when using a working corner? So I looked them up. Actually, the three algorithms were for dealing with the two last edges solved, which either needed to be swapped, or flipped, or swapped and flipped. The swapper is very similar to the one I have learned and used since, but I actually like it better in one sense, with a slight modification.

To swap UR and FR without flipping:

U' R U' R' U' R U' R' U'

To swap and flip UR and FR:

F' U' F U' F' U' F U2

To flip UR and FR:

F' U F U' R U' R' U

Will I actually learn and use these? Probably not. But I like them. :)

There is a slightly different implementation of the Working Corner Method. Arnaud van Galen calls it the Keyhole Method. I like his demonstration better than the one I originally learned. It just dawned on me why he is able to get away with doing it the way he does. He goes ahead and finishes the F2L before going to the last layer, unlike the way Jeays uses the working corner (keyhole) to also get the last layer. Since I no longer use the working corner to get the last layer, I should implement Arnaud's technique.

Jasmine's Scalable Method

http://peter.stillhq.com/jasmine/rubikscubesolution.html

This was the next method I learned. For awhile the idea of speed cubing appealed to me. This promised to be a good beginner's method for those that wanted to go on to faster method's later. Now that I know what I know, I wouldn't recommend this method if your goal is to be able to consistently solve the cube in less than 30 seconds. Rubik's Speedsolver Champion Leyan Lo presents a beginner's method that I like the looks of although I've never learned it. I have recently watched Arnaud van Galen's complete beginner's method video series and recommend them. Gilles Roux presents a beginners' method that is very close to one of my favorite ways of solving the cube. The simplicity and comprehensibility make this method a good place to start if you want to understand the Rubik's Cube. Also, if you are interested in speedcubing you should check out this YouTube video.

After trying for months to get under a minute with both Jasmine's Method and the Corner's First Method—and failing, I finally decided to quit trying and just enjoy cubing at a nice slow pace.

Don't get me wrong. Jasmine's Method has its merits. The sequences for orienting the last layer edges and corners, and permuting the last layer edges are still in my arsenal of useful algorithms.

Adam Cheyer's Corners First Method

Philip Marshall's Ultimate Solution

http://helm.lu/cube/MarshallPhilipp/
After learning to solve the cube corners first, what is next? An Edges First Method! This was a very difficult tutorial to follow, but once I got it, it was my favorite way to solve the cube for awhile. It uses only a few algorithms, and when you are finished solving the cube you feel like you've solved the puzzle, not just used memorized sequences to unscramble it.

Gilles Roux presents a beginners' method that could be used to solve the cube edges first. The simplicity and comprehensibility make this method a good place to start if you want to understand the Rubik's Cube. His technique is much easier to follow than Marshall's.