A Particlely Nice Puzzle - XI

How many XI particles can occupy a small planer space?  Well, that all depends on the spin and orientation of each XI particle.

XI is a restricted opening 2D packing puzzle designed by Haym Hirsh and made by NothingYetDesigns.  The 2 openings in the top permit the XI and anti-XI particles to be injected within the frame.   The anti-XI particles are simply XI particles with a 180 degree spin.  Although the 2 openings conspire to suggest that both XI and anti-XI particles should be injected, it is not obvious how many of each is required or even if both types are needed.  Even if each anti-XI particle cancels out a XI particle as they bounce around and collide with each other, the odd number of particles suggests that the solution will eventually end up as a XI or anti-XI puzzle.  I leave it up to you to find out which.

Needless to say, the particles need to be added in a specific order and potentially rotated as they are entangled.  It’s nice that the top is clear so that you can see what you are doing.  Of course, you have to perform all those particle movements and rotations using the 2 openings.  Fiddly, but not that difficult.  However, if you regularly refer to your digits as sausages, you may find the physics of manipulating small particles more of a challenge.

XI is made with laser cut acrylic and has a nice heft to it.  The use of washers to elevate the clear top ensures that the 5 particles move nicely within the frame.  The puzzle information engraved on the top is also well done and useful for distinguishing the puzzle from other restricted opening 2D packing puzzles by Haym from NothingYetDesigns.

Going Postal - Letter Box

Your task - to stuff a Letter Box with letters until it is completely full.  Oh! - and there are 2664 assemblies.  And you can’t just shove them in, some have to be rotated while they are in the box.  You may even find yourself stuck and frustrated if you’re not careful.

All the letters that you will be stuffing in Letter Box are copies of the L tromino - 9 of them.  They all have to be inserted through the small slot.  When solved, the 9 L trominos will completely fill the Letter Box.

Letter Box, designed by Pit Khiam Goh, was made by Cubicdissection and released in December 2020.  The box is made from Walnut and each of the L trominos is made from a different exotic wood: Wenge, Canxan, Jatoba, Zebra, Bloodwood, Purple Heart, Katalox, Chakte Viga, and Ash.  It’s especially nice that each of the L tromino pieces is made from a single piece of wood.  In addition to the slot that permits the L trominos to pass, there are 2 additional holes that can be used to view and manipulate the pieces within the box.

There are many ways to tackle a puzzle.  Since this puzzle has 2664 assemblies, I wouldn’t recommend an exhaustive approach to try each one until you find one that works.  Even if you found a working assembly, it may not be obvious since the solution requires rotating pieces within the box.  For this puzzle, a better approach would be to start at the other end and envision how the pieces would be removed from the box.  How would the first piece come out?  Then with the first piece out, how would the second piece come out?  Using this approach, I was able to find a workable assembly and determine the rotations needed to solve Letter Box.  Not overly difficult but a very nice challenge.

Puzzling Preparation Purgatory – Helical Bits and Pieces

I recently had the opportunity to acquire some nice helical puzzles from one of the Two Brass Monkeys.  I’ve been eyeing these types of puzzles for years and finally acquired some when a set became available on Puzzle Paradise.  Included in the set were: HeLLical Burr, Oliver Twist, Twiddle Dee, Twiddle Dum, and Dodekastar (improved).  The first 4 were designed by Derek Bosch and are from his line of helical burrs, which he has been expanding over many years.  Although Dodekastar is not a helical burr, it is a great puzzle designed by Yavuz Demirhan and tweaked by the Two Brass Monkeys to be more difficult.  A nice little additional fidget puzzle was also included, which was the only puzzle to arrive already disassembled.

Puzzles arriving in their solved state is a sin and need to be disassembled into purgatory before being redeemed into a solved state.  Although a sinful puzzle and one that has been redeemed share the same outward appearance, deep down, you know the difference.  Every serious puzzle collector is able to scan their collection and weigh their sins against redemption.

Having received this batch of sinful puzzles, I quickly (or not so quickly) banished the puzzles to purgatory (a nice looking decorative bowl) for all eternity (the average amount of time it takes me to get around to solving puzzles).  Most were straight-forward, but one of the Twiddle twins (I really don’t know which is which), was a bit of a challenge.  I was also surprised to find out that Dodekastar was a challenge to take apart as well.  A lot of movement, but no obvious exit point.

Stay tuned for further updates on these puzzles as they are redeemed and take on their divine forms.

Puzzle Of A Year! – 20-22

20-22 is a level 22.02 puzzle announced on Twosday, 22.02.2022, by PuzzleWillBePlayed (PWBP).   It was designed by Stéphane Chomine and consists of 2 pieces that fit within a frame.  When solved, one side shows the numerals 20 and the other 22.

I always check out the new puzzles released on PWBP and this one caught my eye and interest.  I quickly printed a copy with a gray frame and red pieces.  One piece has a 2 on each side and the other has a 2 on one side and a 0 on the other.  Of course, the frame has some internal obstructions keeping the pieces from simply sliding in.  Must be a puzzle.

This puzzle embodies several qualities that facilitate the solving process.  The first is the level.   At 22 moves, you would expect it to be non-trivial but not too hard.  The second is that the piece with a 2 on each side is the same when you rotate it 180 degrees on any axis.  That means that you can’t possibly add this piece incorrectly.  You just need to figure out which side of the frame it belongs to.  Lastly, since the piece with the 0 can go in the frame in four different ways, there are only 4 assemblies to check.  With a little experimentation, the complete pas de deux is revealed as the pieces find their final resting place.

A special thanks to all the MPD’rs that unknowingly contributed to this post.

X-tra Protection – T Lock

Last week’s blog got me thinking about protection so I thought it might be time to circle back and cover T Lock, the second of Andrew Crowell’s 3D printed burr locks that I recently acquired.  It certainly has secured a well-deserved spot in my collection of enjoyable puzzles.

Like Side Lock (www.zenpuzzler.com/2022/01/put-it-to-side-lock.html), T lock has a main frame (for all you old programmers out there), a shackle, and 4 T pieces that are packed in the frame.  The pieces are nicely 3D printed in gray, red, and yellow.  Since it doesn’t have the fifth piece running side-to-side like Side Lock, I expected it to be slightly easier.  Of course, it turned out to be slightly harder.  T Lock requires 15 moves to remove the first piece compared to 19 moves for Side Lock, but T Lock requires a rotation, which gives it that boost in difficulty.  Recall that puzzle difficulty = cube root of total voxels * pieces * highest piece moves * log(10 + rotations * 100)  / 100.  {Factors to compensate for things like n-ary inflation have been dropped for simplicity.   Compensating factors for piece surface area have also been removed since they are a pain to compute.  However, for designers that needlessly increase voxel resolution, these factors should be added back in.}

I’d like to describe how easy the original disassembly was, but it was so long ago I can’t remember.  This became all too obvious as I worked to get it back together.  In fact, I forgot that a rotation was required, which really is the crux move of this puzzle.  Needless to say, accomplishing the solve was a challenge.

The frame has 3 impeding cubies attached inside to help you figure out where you can, or more appropriately, where you can’t, put pieces.  These cubies only permit the shackle to be inserted in one orientation, so you can also add the shackle to places where pieces can’t go.  With some work, you can then determine where the 4 T pieces go, although I admit to doubting this configuration many times and re-examining it.  Trying to get those 4 pieces in the frame took some effort.  Once I finally figured out which 2 pieces needed to go in first, I had a devil of a time trying to get them situated in the frame.  

Typical Crowell puzzle scenario – struggling to get 2 small pieces in a big open frame.  Been there many times.  This is where I spent most of the time in the assembly until I finally enjoyed the Aha moment that resulted in not just the first 2 pieces in the frame, but all 4.  

T Lock is difficult and very satisfying as an assembly puzzle.  Having done it several times now, although not as difficult as an assembly puzzle, attacking it as a disassembly puzzle is interesting as well.  You can get copies of T Lock on Andrew’s online store, ARC Puzzles.

Happy VD! – Broken Heart

It’s that time of year when love in the air and our thoughts turn to VD.  Yes, it’s time again to celebrate Valentine’s Day with your special loved one on 14 February.  To celebrate this special occasion, I ordered a love themed puzzle to share with my better half – Broken Heart by Techno Angels and Bozoou.

Broken Heart is a 2D packing puzzle from JIGSAWHOLIC, made with laser cut acrylic pieces and a plastic tray.  The puzzle arrives in a plastic bag, which states that the level of difficulty is 6 out of 10 and that the goal is to put all 19 pieces into the frame.  Seventeen of the pieces are black and two of them are red.  The matte finish on the black pieces looks fantastic!   

It also comes with a drawstring bag with the warning, “open after you solve the puzzle”, and feels like it contains another piece.  We all know what that means!  Having recently completed all three original Magic Puzzles, a morphing surprise was certainly expected.

In the true Valentine’s spirit, I solved the puzzle with my wife.  We both started putting puzzles pieces in the tray and in less than 5 minutes, we had all 19 pieces in the tray with an obvious piece missing.  Opening the drawstring bag, we took out the final piece and added it to the tray.  What gives?  Where’s the magic?  Where’s the Aha moment?

If you do enough puzzles, you realize that sometimes you just get lucky and stumble upon the solution right away and miss out on the brilliance of the puzzle.  So I spent some time examining the pieces to find what I had missed.  Unfortunately, I wasn’t smart enough to discover the genius behind this puzzle.  I’m currently under the impression that the Aha moment is to realize that you need the configuration that we discovered at the beginning.  There is a little effort to lead you away from this configuration, but there is an even greater pull to bring you towards it.  To be fair, the website does warn that 30% of the people are not going to experience the “twist”.  In the end, it’s a nicely made jigsaw puzzle that may help you score (some points) on Valentine’s Day.

If all you are looking for is a quickie on Valentine’s Day, a Broken Heart may be just what you deserve.

Wonderizing Puzzles – Benno’s TIC 2.0

As I was enjoying perusing through the myriad of beautiful puzzle photos on the Mechanical Puzzles Discord (MPD) server, I saw a particularly attractive puzzle made from several exotic woods.  Paduak, Redheart, Canarywood, Yellowheart, Maple, and Walnut comprised this intriguing puzzle made by George Syriaque.  The story behind the puzzle was as interesting as the puzzle itself.

George was fascinated by a puzzle designed by Benno de Grote called Favorite.  It is level 7 puzzle and George was interested in knowing if the complexity could be increased.  To scratch that itch, he shipped the design off to Andrew Crowell to pass it through his Magical Puzzle Wonderizer.  For those of you unfamiliar with the Andrew’s Wonderizer, it takes a plain puzzle design as input, breaks it down to its core puzzle DNA, injects complexity steroids, and reconstitutes its components into its new uber form.  So what would happen if you put in a design that was already great to begin with?  Would it strip out the elegance and produce a quotidian block of wood?  As it turns out, the Wonderizer took the level 7 puzzle and produced a level 16 puzzle with some added rotations sprinkled in, which was summarily named Benno's TIC 2.0.

For a long time now, George has been posting enticing photos of the puzzles that he has been making, whetting everyone’s appetite for more wooden puzzles.   Certainly not immune to that allure, as I gazed upon the photos of Benno’s TIC 2.0, I said to myself, “I’d love to give that puzzle a try”.  And then I moved on since they were not being produced.

Several weeks later, I received a package.  A package from my good friend George.  A package that contained a single cubic box.  The kind of nondesript white foldup box that puzzles sometimes come in.  Inside this box was, you guessed it – some foam wrapping!  Yes!!! Foam wrapping!   That's such a good sign!  And sure enough, protected by that foam wrapping was Benno’s TIC 2.0 that I saw on the MPD.  WOW!!!

Instead of drooling over pictures on the MPD, I now had one in hand.  TICs are my thing and…I can’t find the first move.  That first piece fits snuggly in the cube and took a couple of minutes to locate.  After a couple more moves, things start to open up and you may find that you are going in circles.   However, once you break out of that circle, pieces start emerging from the cube.

The dance required to separate the last 3 pieces was particularly nice.  Looks like it would be easy, feels like it’s impossible, and is greatly appreciated when you finally successfully traverse the correct path.  Need I say that the path is a bit twisted.

Reassembling the puzzle right after disassembly while all the moves are fresh in mind is easy.  It is much more interesting to leave it unassembled and tackle discovering the moves in reverse.

Since I don’t have a copy of the original Favorite design by Benno, I can’t comment on the differences between the original and the wonderized version.  I can say that the Benno’s TIC 2.0 is a great design and fun to solve.  Thank you George!  Thank you Andrew!  Thank you Benno!