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Wednesday, November 13, 2019

A New Spin on Puzzling - Tetra Spinner

Tetra Spinner by Yasuhiro Hashimoto and Mineyuki Uyematsu“That’s a novel take on packing tetrominoes”.  That was my initial thought when I saw Tetra Spinner while perusing the IPP39 Nob Yoshigahara Puzzle Design Competition entries.  I was intrigued and looking forward to trying it.

Tetra Spinner was designed by Yasuhiro Hashimoto and Mineyuki Uyematsu and was one of the top ten vote getters in the competition.  I got my chance to try it at the Rochester Puzzle Picnic (A Decade of Puzzling - RPP 2019).

It’s made from plexiglass and consists of a frame and all 5 tetrominoes (i.e., the free ones and not the extra 2 one-sided ones).  Tetrominoe is just a fancy name for a connected shape made from 4 squares in a plane.  Each of the tetrominoes in Tetra Spinner is a different color making it an eye catcher.  However, it’s the frame that gives this puzzle it’s unique appeal.  The frame is comprised of 3 layers of plexiglass.  The outer 2 layers are clear and bolted together through the center.  There is a spacer in the middle around the bolt to keep the two outer layers apart.  The middle layer has the same dimensions as the outer layer but most of the interior has been removed to make room for the tetrominoes.  The center layer can be moved and rotated around the middle but is restricted by the spacer holding the outer pieces.

The objective is to place the five tetrominoe pieces in the middle layer so that the middle layer is centered within the puzzle.  This requires that you move the white plexiglass frame as far as it will go so that you can add pieces to the empty areas that now hang outside the outer layers.  However, the more pieces that you add, the more difficult it is to move the frame of the middle layer.  This requires determining where the pieces need to go within the frame and the order that they need to be added.  Oh, and while you’re doing that, you need to determine how the pieces and frame need to be moved around to accomplish all that.

I didn’t find this puzzle difficult but it was fun to solve.  I didn’t include the photo of the puzzle in the solved state, since it would give away part of the solving process.  It would certainly give away the first piece that would be removed although this should become obvious rather quickly in the solving process.  Yes, that was a hint, but I’m sure you were already thinking about it.  It’s only cheating if you go back 2 sentences and reread it to understand it.

S,Z,J,and L Tetrominoes
S,Z,J,and L Tetrominoes
Before concluding, I feel compelled to explain the reference to free tetrominoes to save readers the embarrassment of getting caught leaving the puzzle store without paying for tetrominoe related puzzles.  There are 5 tetrominoes if you regard the pieces irrespective of orientation.  These are referred to as free tetrominoes.  There are 7 tetrominoe shapes if you are not allowed to turn them over.  These are referred to as one-sided tetrominoes.  The difference between the free tetrominoes and the one-sided tetrominoes is due to the 2 pieces that can be flipped over to provide a different shape; the S piece becomes the Z piece and the J piece becomes the L piece.

10 comments:

  1. So the middle piece doesn't just spin - it will slide until an edge (or a tetromino) hits the center post? Maybe a picture of the frame with the center bit extended would be good?

    Is this on sale anywhere?

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    1. You are correct in your description of how it moves. I would have liked to have had more pictures showing how the center layer moved but I don't own a copy of the puzzle and I didn't have the foresight to take more pictures when I played with it. By habit, I take a picture of a puzzle when I solve it and then another picture of the pieces after I take it apart. Unfortunately, since the solved puzzle picture is a big spoiler, I was only left with the one photo of the pieces that I could use.

      I haven't seen Tetra Spinner on sale anywhere, but the IPP puzzle design competition says: "Available ONLY in Japan at PUZZLE of MINE * WEB-SHOP". I wish you luck in your search and if I hear about it becoming available, I'll let you know.

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  2. how can we get it?

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    1. That's a good question and unfortunately, I don't have a good answer. The IPP puzzle design competition says: "Available ONLY in Japan at PUZZLE of MINE * WEB-SHOP", but I didn't see it listed on the site. If I hear about it becoming available, I'll add another comment with the details.

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  3. Many of the puzzles from ipp38 were supposed to be crafted later by MINE, but at the end: nothing. Hope the ipp39 puzzles will be made this time !!

    PS: don't hesitate to add my blog to the blog you follow if you like it :)

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    1. Tetra Spinner seems like a good candidate for production since it looks like it can be commercially produced at a reasonable cost. Maybe this one will have better luck than last year's entries.

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  4. I actually contacted Eric Fuller to find out if he could get permission to make Hajime Katsumoto's 5L Box. He had already contacted MINE about this puzzle and said his request was denied. Doesn't matter anyway, since Eric discontinued his Artisan Series puzzles and I can no longer afford his work.

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    1. This touches on the delicate subject of puzzle trafficking for profit that causes unrest within the puzzle community. It impacts business dealings between designers, craftsmen, and puzzle shops as well as interactions in the puzzle auctions. In most cases there is no foul committed by either party. There is only the understanding that a deal cannot be struck. The fact that Eric and MINE did not enter an agreement on the 5L box is not surprising, unusual, or an issue. It's just a simple business decision between 2 well-known and respected members of the community.

      I feel your frustration on not being able to financially support your habit in the way that you would like. I've recently had to severely trim my own puzzle budget and I'm always disappointed to see so many grand new designs come out that I'll never be able to acquire or even play with. However, I do have a significant backlog of unsolved puzzles and I hope that you have one as well.

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  5. Nice little puzzle! The objective just says "fit all the pieces in the frame", so it wasn't entirely clear to me that the middle frame also needs to be centered. But thinking about how to center the middle frame helped me solve the puzzle!

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  6. Thanks for pointing that out George. If the middle layer wasn't centered, the solution wouldn't be as elegant. Sorry that I couldn't provide a picture of the puzzle in the solved state. I thought it would provide too much information and spoil a large part of the solving process. I'm glad you liked the puzzle. It was a clever idea.

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