Pages

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.

Wednesday, November 6, 2019

Yanked My Chain - Chain Store

Chain Store by Goh Pit Khiam


Sometimes a puzzle just yanks your chain, which is exactly what happened with Chain Store.

One of the joys of attending the International Puzzle Party is spending time playing with the entries in the Nob Yoshigahara Puzzle Design Competition.  This is a puzzling wonderland full of all sorts of new designs for a wide variety of puzzle types.  There is something for everyone and I try to spend as much time as possible in the design competition room socializing with other puzzlers doing the same.

One entry in the IPP36 Nob Yoshigahara Puzzle Design Competition was Chain store, designed by Goh Pit Khiam.  It was made by master craftsman Tom Lensch and won the Jury Honorable Mention award.

Chain Store by Goh Pit Khiam - Chain Partially InsertedI looked at it and said to myself, how difficult could it be to put a 5-link chain in a box?  Apparently, 5 links are plenty sufficient to provide all sorts of awkward positioning to frustrate the packing process.  The links are 4x6 allowing the width of the link to just fit inside another link.  And then what about the box?  Do the links go in orthogonally or do they end up at an angle?  I spent a lot of time hypothesizing how the links would sit within the box and then trying to orient the links in the direction that I needed.  It turns out that turning links made from square material takes more forethought and planning than links made from cylindrical stock.  In the end, it took more of an effort than I could muster in the design competition room.

Now I have a question for you.  Would you rather buy a puzzle that you have already solved or that puzzle that you didn’t quit manage to solve?  Personally, I tend to buy puzzles that I haven’t solved.  Once I’ve solve a puzzle, I’ve basically scratched that itch.  Of course, some puzzles are so brilliant you need to acquire a copy even after solving them to occasionally wonder at and show others.  Case in point is Stumbling Blocks also by Goh Pit Khiam, and a top 10 vote getter in the IPP36 design competition.  I solved Stumbling Blocks very quickly but the movement is so spectacular, I needed to acquire a copy.

Chain Store by Goh Pit Khiam - Chain Mostly InsertedWhen I saw Tom Lensch at the following Rochester Puzzle Picnic, I made sure to acquire a copy of Chain Store as well as Stumbling Blocks.  After returning home, I played with Chain Store attempting to get all 5 of those links inside the box without peaking over the lip at the top.  I had heard that an earlier version of the box was slightly bigger and that it allowed an alternate solution.  While I was working on Chain Store, there were several times that I wished that I had the original box.

At some point, the chain was sufficiently yanked to turn the light bulb on and I managed to stuff those stubborn links into that wee little box.  Once I discovered the required orientation for the links, I found that there is an elegant way to crumple up the chain to pack in the box.

I really liked this puzzle and if you are interested in acquiring a copy, Cubicdissection is planning on releasing a run in the near future.

Chain Store by Goh Pit Khiam - Tom Lensch Logo


Wednesday, October 30, 2019

Off With Her Head! Part 2 - Skull

Woo with Skull




Skull by BePuzzledNot long ago, I reviewed Guillotine, which posed the threat: Off With Her Head!  This review picks up where that one left off and addresses the aftermath of the successful execution of that task. 


It’s frightening how many pieces there are to this crushed Skull - 48 in total.  It’s almost like a puzzle!  In the post on Puzzle Complexity, the number of pieces was offered as a potential indicator of difficulty.  However, a counter example of jigsaw puzzles was offered as a case where the level of difficulty may not increase exponentially with piece count.  This is the case with the Skull puzzle, where you can determine from examining the pieces that it is essentially a 3D jigsaw puzzle.  Not only is it a 3D jigsaw puzzle, but all the pieces are edge pieces.  Armed with this information, I figured that this would be a piece of cake and jumped right into the pile.  This is how all horror movies start - bright smiles and lot of optimism!

Skull Pieces
In no time at all, I had discovered the key piece.  This was largely accomplished by the fact that it had “KEY” stamped on it.  However, I was haunted by the thought that I didn’t know what to do with it as I was assembling the puzzle.  I failed to notice that the back of the box had “Skull Assembly Hints” that indicated exactly what needed to be done with the key piece.  My recommendation is to try to avoid the hint and discover it yourself.  You’ll certainly figure it out in less time than I did.


Skull Key PieceThe fact that the pieces are clear with no drawings or patterns means that you are putting the pieces together by shape and being a skull, there are no easily recognizable ear, eye, or nose shapes to look for.  I also avoided looking at the picture on the box for any clues.  Yes, it was bit intimidating to find a starting point amongst all those ghostly pieces.  In the end, I ended up working from both ends and ended with sandwiching the 2 end assemblies together. Once I had the process underway, it was not that difficult to construct the Skull.

Flaming Skull
It should come as no surprise that the Skull has quite a bit of empty space between where the ears should be when fully assembled.  You could add something inside … like … maybe … a small battery and some LEDs and/or a little sound generator?  What would Chinny do? 


Skull is one of the Original 3D Crystal Puzzles from BePuzzled and has a difficulty rating of 2 out of 3.  It is available from Puzzle Master in black like I have or red.  Double check your order before buying or you may end up with something you didn’t expect like me when I tried to purchase a Puzzle Skill.

Happy Halloween and take some time to enjoy a spooky puzzle!

Wednesday, October 23, 2019

Molnar Scores Again! - Hat Trick

Hat Trick PiecesA hat trick in sports is a reference to 3 of something.  When I was a kid, my folks used to watch hockey, so I was brought up to recognize a hat trick as 3 goals scored by a player in a game.  Other sports have similar definitions of a hat trick.  I’m sticking with hockey since Hat Trick, the puzzle, obviously has 6 hockey sticks (one for each player on a hockey team) with a goal - of packing them all in the restricted opening box.

Hat trick was designed by Laszlo Molnar and entered in the IPP39 Nob Yoshigahara Puzzle Design Competition where it was one of the top 10 vote getters.  When the competition entries were originally announced, I was intrigued by this puzzle and attempted to solve this puzzle as a mental exercise without having a physical copy.  I finally encountered a copy at the Rochester Puzzle Picnic (A Decade of Puzzling - RPP 2019).  Brian Menold from Wood Wonders brought several copies to RPP in a variety of different woods.  They were so beautiful, I ended up taking one with an Orange Agate box and Redheart pieces home with me.  I particularly like the look of the Redheart corners on the Orange Agate box.

So, what is Hat Trick all about?  It consists 6 hockey sticks or if you prefer, you can just think of them as L shaped pieces that are 3x2x1.  These hockey sticks can be stored in the accompanying box that has an interior space of 2x3x4.  The only problem is that someone made the opening in the storage box too small to simply dump the hockey sticks in.  It only has a small T-shaped opening in the top.  This type of faulty craftsmanship turns an easy job into a complex process, or what we fondly call: a puzzle.

Hat Trick by Laszlo MolnarOnce I had a physical copy, I was able to verify the solution that I had envisioned when viewing the puzzle competition design entry listing.  The solving process for this puzzle is fairly straight-forward.  Since this is a fully packed restricted opening box with 6 identical pieces, it is obvious where the last piece in (or first piece out) is located.  With that information, there aren’t too many 2x3x4 assemblies left to check.  It becomes obvious early on that rotations are required to insert and manipulate the pieces.  Understanding the possible rotations that can be made is the key to achieving the required assembly.

Compared to other recent packing puzzle designs, I found this one to be on the easier side.  It would make a nice challenge for a new puzzler.  The key movement required to orient the pieces is clever and provides a very nice Aha moment.

Hat Trick is currently sold out on Wood Wonders but it’s possible that it may show up again.

Wednesday, October 16, 2019

Uns@lv*bl# F!&#ing O$j@ct - Cast UFO

Cast UFO by Vesa Timonen



Cast UFO BoxEvery once in a while, something shows up out of nowhere and descends upon the unsuspecting world.  This was the case with Cast UFO, and when it landed, it made a big impact.

Cast UFO was designed by Vesa Timonen.  I know this because Vesa’s name is the only thing that I can read on the back of the Hanayama Huzzle box.  UFO is a sphere trapped within a frame, somewhat reminiscent of Cast Marble ().  The frame looks like it needs to slide apart to be separated, but the internal sphere, which can be seen through the hole in the top and bottom, is in the way.  The sphere can be rotated within the frame and it appears that the sphere is divided into quarters.  The orientation of the quarters can also be changed by rotating any half of the sphere along either cutting plane.  Although each of the quarters looks the same, peering into the cracks reveals that the quarters are not simple wedges and that there is some fancy geometry going on that allows the rotations but doesn’t seem to allow it to come apart.  Maybe it’s a puzzle.

Cast UFO PiecesI played with this one on and off for quite a while.  After a month, I was having serious doubts about being able to solve it.  For the longest time, it was like the fidget spinner on my kitchen table – something to twirl every once in a while without getting anywhere.  Along the way, I was comforted by the thought that the sphere has an infinite number of possible orientations within the cube and that there was no way to identify them since the quarters all look the same.  At one point, I almost decided to use a marker to be able to identify the pieces, but decided not to in the end.  Warning – using stickers would be a realllllly bad idea.

I started out with what I thought was a reasonable approach to solving it but I wasn’t getting anywhere.  Thinking about it some more, I came up with 2 other approaches to disassembling the puzzle.  Alternating between the 3 approaches, I finally managed to get it apart.  Once I had it all apart my first reaction was relief for finally getting apart.  This was quickly followed by the horrifying experience of noticing identifying numbers on the inside of the sphere pieces, which I failed to notice when taking it apart.  I now had 6 pieces staring back at me with no indication of how they were originally oriented.  The good news is that once you take UFO apart, it is rather easy to determine how the pieces should be oriented and put back together.  However, even knowing the solution, it’s still an effort to take apart.

Cast UFO Piece NumberingSo why does everyone hate this puzzle so much.  It’s rare that a puzzle receives negative reviews and this one seems to be attracting them.  It’s not that it’s a bad design.  It’s a brilliant design.  The problem with this puzzle is in the packaging.  That’s right, it’s not the puzzle but the box that it came in.  It was the presentation that did this puzzle in.  Right on the front of the box, it was declared that this puzzle was 4 stars out of 6 in difficulty.  So we all put on our 4 star hats and took our 4 star game out to solve this tough nut.  But we came unprepared to the game and we felt mislead and cheated.  Had the puzzle been given a 6-star rating, puzzlers would have enjoyed it more even though some would have declared that it was too easy to justify a level 6.  Folks that normally avoid the most difficult puzzles in the series would have been steered clear of this trap.  Even 5 stars might have appeased everyone.

Let’s get back to the design.  I’ve already mentioned that it’s brilliant and it is.  It was obviously designed to be difficult and it certainly succeeded.  Once you take it apart, you can appreciate Vesa’s genius for creating these types of puzzles.  This puzzle has very tight tolerances and you have to have everything lined up just right to start the disassembly.  I’ve seen at least one reference on the Internet that indicated that a pre-production version, was used for testing.  This version most likely had bigger tolerances, which would have made it easier to disassemble, resulting in the easier rating.

I will mention that there is a significant clue that I completely failed to notice that would have been a great help in the beginning.

I bought my version of Cast UFO from Puzzle Master and if the more difficult Hanayama puzzles appeal to you, you can get a copy here.

Wednesday, October 9, 2019

Just Plain Mean - Split Cube 2


Split Cube 2 by Andrew CrowellAntigravity, EM wave theory, and centrifugal force computations were just some of the techniques I employed to solve this beautiful little puzzle, but don’t let her looks fool you, she’s a beast!  You can’t see what’s going on in her head and that’s the problem.  It’s a blind solving process.  However, it’s obvious that she has some loose marbles rolling around in her head.

Before Andrew Crowell started providing those wonderful TIC designs for the puzzle community, he developed a few other puzzle series based on the 4x4x4 cubic dissection.  Normally with a 4x4x4 cubic dissection, you have up to 64 cubes (4 layers of 4x4 cubes) where the puzzle design specifies which cubes are removed and which of the remaining cubes are glued to each other.  Not satisfied with this Andrew decided that some of the internal cubes should be round and replaced them with marbles.  This helps the internal pieces move without getting stuck.  You will appreciate this, until you don’t, and then you’ll be cursing it.  Now take this nice puzzle that I just described and add one more additional feature and she becomes the frustrating hair-pulling demoness called Split Cube 2.  Keep in mind that none of the features of this puzzle are meant to help you, they are ALL designed to hurt you.  Andrew mentioned to me that he was tempted to call this series Just Plain Mean.

I have to confess that before I met up with Andrew’s puzzles, I had no desire to spend time on a “blind” solution process.  However, I really love these puzzles and found them quite challenging as well as enjoyable.

Split Cube 2 by Andrew Crowell (Prototype)I received Split Cube 2 from Andrew as a prototype that he wanted feedback on.  Andrew’s comment to me was: My goal was to make very tough/frustrating puzzles, because a few people asked for something more difficult, but these might be too tough to be enjoyable ...  I assuaged Andrew’s fears by informing him that these are the types of puzzles that the puzzle community eats for breakfast.  There’s a lot of fiber in wood.

What Andrew calls a prototype, is what I aspire to make someday.  The prototype is beautifully made with Purpleheart, Padauk, Walnut, and Maple.  When I was done, I liked Split Cube 2 so much that I got a second copy in the final wood selections of Tigerwood and Purpleheart rather than give the prototype up.  Both copies have the edges of the cube beveled but the edges of the individual pieces are not beveled, which looks fantastic on this puzzle and provides no clues as to which cubes are connected to each other.

Split Cube 2 PiecesAs part of the review process, I timed myself to provide the first benchmark on how long it takes to solve.  It took me 1 hour and 45 minutes to completely disassemble the puzzle.  If you would like that broken down into stages: it took 1 hour and 40 minutes to get the first marble out and 5 minutes to completely take her apart.  With puzzle boxes, you know you are done with the solution when you find the designer’s Hanko (stamped signature).  It would be nice if future versions of this puzzle revealed the Hanko when the last 2 pieces are separated to let you know you are done.

This is a difficult puzzle and normally I wouldn’t have solved it that fast.  There were 2 things working in my favor.  The first is that I was timing myself and therefore very focused and moving faster than normal.  The second is that I had already solved Split Cube 1 as well as the 4 Exolution puzzles, that gave me some idea of what to expect in this puzzle.  Most of the time is spent experimenting with the cube to get some kind of feedback that helps generate a mental map of the internals and how the framing pieces are constructed.  With the mental map, you can hypothesize how she would come apart and the moves required to accomplish it.  And finally, you test the hypothesis to find out it doesn’t work and start all over again, and again, and again…

I like Split Cube 2 because she’s Just Plain Mean.  This puzzle has teeth and once you get her apart, you will see exactly where the teeth (OK, tooth) are and you can put it back together without this tooth to make it a very attractive and fun beginner level puzzle.  If you want to challenge somebody, you can leave it in.

So here is my confession.  Yes, I can get her open and I can even do it relatively quickly.  However, my solving process for this particular puzzle is extremely unusual and I’ve failed to come up with a straight-forward method for solving it.  If you find one, I’d be interested in hearing about it.

I highly recommend this puzzle and if you are up for a challenge, you should get one.  Cubicdissection is currently planning on releasing a run of these in the near future.

Split Cube 2 Puzzles by Andrew Crowell

Wednesday, October 2, 2019

Providing Solutions, A Slippery Slope - Cast Slider (Redacted)



Hanayama Cast Slider by Vesa Timonen
My regular Hanayama pusher inquired if I wanted a copy of Cast Slider and I declined.    I felt that a puzzle with 3 stars from Hanayama would not provide enough of a challenge to be that interesting.  I’ve made it a point to collect all the Hanayama puzzles that are 4 stars and higher.  It’s not that I don’t own any easier Hanayama cast puzzles.  I have a copy of Cast Loop, which is 1 star.  It may not be difficult, but I like the movement and it’s a good puzzle to hand to a new puzzler.

My first Hanayama puzzle was Cast Enigma (6 stars), which started me on this path.  As I get older, the numbers seem to be skewing to the left.  I’m thinking that maybe I should reevaluate my abilities and collect puzzles that are 3 stars and higher.  Anyone that has been beaten up by Cast UFO (4 stars) recently can certainly sympathize.

When recently purchasing some puzzles from Puzzle Master to support a puzzle challenge (Puzzle-A-Month Challenge), I decided to add Cast Slider to the cart and give it a try.  I took it with me to the barber and solved it while waiting to get my hair cut.

Cast Slider was designed by Vesa Timonen and consists of 3 pieces, the 2 sliders and a central hub piece that they slide on.  Each slider consists of two flat sides that are connected on each end by a large pin.  One side is extended with a grove that the hub’s pin runs along.  The hub’s pin extends out of both sides of the hub to interact with each slider.  The hub also has a slots cut in it to allow the slider’s pin’s to travel along it.

Here is a blow by blow description of the heart-pounding disassembly process, slightly redacted to preserve against spoilage.   Of course, the person responsible for the redaction is ██████████.

When handling this puzzle, it is apparent early on that the only available move is to █████████████ releasing █████████████████████████  and then Boom! Things start to  █████████████████████████████████ until the sliders flop around, hanging loose by one end on the hub.  Although it looks like they might be able to come off, they just can’t seem to get past the hub’s pin.


After some experimentation, it becomes obvious that █████████████████ are █████████████████████.  With a little further experimentation, it becomes apparent that you need to ██████████████████████ and ████████████████████████, ██████████████████████ is infinity squared bigger than infinity? ████████████████████. ████████████████████████ won’t get you anywhere but ██████████████████████████████████ will █████████████████████ allowing you to ████████████████████████ for the climactic ending where you can ████████████████████████ like magic.  Indeed, if you practiced this enough, you could make it look like a magic trick.

Hanayama Cast Slider PiecesAs you can see from the solution description, this puzzle is not that difficult but has some interesting moves.  Assembling the puzzle would be more of a challenge than disassembly if you haven’t gone through the disassembly process.  However, I consider Slider a disassembly puzzle and wouldn’t recommend starting with the assembly.  I was able to do this puzzle in a few minutes, but I have handed it to others who have found it more challenging than I did.

If you are interested in getting your own copy, you can get Cast Slider from Puzzle Master here.  If you get stuck, just follow the directions in the solution above.

P.S. I gave the puzzle to my wife to work on after she read the solution above and she's still not talking to me.  Great puzzle!