Wednesday, July 29, 2020

Starting With The Seed Of An Idea - Begonia

Begonia by Yavuz Demirhan

Begonia PiecesBack in 2012, when puzzlers were puzzlers and packing puzzles were packing puzzles and not those new-fangled hoity-toity 3-piece pack jobs where you have to rotate your piece where the sun don’t shine, a seed of an idea bloomed in the corner of Yavuz Demirhan’s mind.  This seed eventually grew into our 3 dimensional reality with 3 petals.  Each 4x4 petal occupied its own plane of existence except for where the planes met.  Yavuz divided the 3 petals into 8 pieces, 4 planer and 4 non-planer, and left only the seed in place within the frame of reference.  He named his creation, Begonia.  And it was good!

Cubicdissection released Begonia in 2013 and did an excellent job in making these puzzles from Walnut and Rosewood.  The Walnut frame is solidly built and has the same thickness as the Rosewood pieces.  It also has Rosewood splines that add a nice touch.  However, the splines are very subtle and tend to blend in with the rest of the frame depending on the lighting.  All the external edges of the frame are slightly beveled to give them a nice feel.  All the pieces are beveled as well and move nicely within the frame, which is very important if you end up moving them for hours like I did.

Last Piece Doesn't FitThe objective of Begonia is to fill the 36 empty spaces within the open frame with the 8 pieces comprised of 36 cubies.  This is easier said than done.  I found myself doing the same things over and over while trying to avoid performing a completely boring brute force search.  I compromised and selected one of the planer pieces to always start with and checking all the ways that it could lie within the plane.  There are 2 main facts that I used to recognize futile attempts.  The 4 non-planer pieces have to be placed where the planes meet and the 3 empty spaces furthest from the inner corner have to be occupied by planer pieces.

I wish I could say that I used some brilliant deductive reasoning to discover the solution to this puzzle, but that’s just wishful thinking.  If the objective was to put 7 pieces in and have the remaining space match one of the already placed pieces instead of the 8th one I was holding, I think I found all of those solutions.

Begonia 3x3x4 ChallengeWhat makes Begonia so difficult is that there is a single solution and many ways to insert 7 pieces without getting the last one in.  Just for fun, I plugged it into BurrTools and found that there are 50,023 ways to put in 7 pieces without getting the last one in.  That made me feel a little better that it ONLY took me a couple of days to find the solution.

If you find yourself getting frustrated while trying to find the solution to Begonia, you could always back off and find one of the 2811 ways to build a 3x3x4 rectangular parallelepiped.  It’s much easier.  You may even be tempted to find all 2811 solutions before finding the sole solution to Begonia.

For the record, I do like those new-fangled hoity-toity 3-piece pack jobs and I’ve enjoyed solving many of them over the years.

Wednesday, July 22, 2020

The Bane of All Cubes - Cubane

Cubane by Masumi Ohno

As if the bane of all cubes wasn’t enough, Cubicdissection has announced that they are looking to release Cubane II in the near future pending the development of a successful prototype.  This got me thinking that maybe I should solve Cubane I, or just Cubane as it was called when released, before the second one comes out.

Cubane was designed by Masumi Ohno and released by Cubicdissection in 2015.  It was available in 3 different wood combinations and the one that I have is made with Shedua and Bloodwood.  A version made from Wenge and Padauk was entered in the 2015 Nob Yoshigahara Puzzle Design Competition, although that version was not as well-made as the one from Cubicdissection.

Cubane PiecesThe puzzle consists of two pieces: a frame and a shuttle.  The objective is the remove the shuttle from frame.  There is a well identified starting point that aligns a magnet on the shuttle with a magnet on the frame to keep it in place until you start.  The 2 sides of the shuttle are held together by a dowel on one side, while the other side has a larger dowel that sticks out but does not span the distance between the 2 sides of the shuttle.  The sides of the frame have cuts in them to let the smaller dowel pass through, notches that permit the larger dowel to pass through, and rounded edges that allow the shuttle to be rotated by 90 degrees.  Each edge of the frame supports up to 5 of these mechanisms.  The exit point is easy to identify since it is a combination of a cut and a notch that allows both ends of the shuttle to pass.

With the frame cut in 4 places, you may think that it might be flimsy.  However, Cubicdissection has taken great pains to make solid joints to avoid that from happening.  It would be possible to make a fifth cut, but that may be pushing it.

Cubane Close UpWith 12 edges on the frame and 16 ways that the shuttle can reside on each edge, there are 96 possible states that Cubane can be in (+1 for when the shuttle is removed).  Of course, not all states can be reached, making the number of obtainable states smaller.  I didn’t make a state map, but none is really needed and it doesn’t take long to solve.

Is it really the bane of all cubes?  Nah!  But it's really clever and fun to fiddle with.  The first few minutes of the puzzle are the best.  This is where you explore the different ways the shuttle can move and pass between the edges.  I won’t include any spoilers here on the different ways that may occur, but it is very clever.

I’m looking forward to seeing what new features Cubane II will offer.  The fifth edge cut?  Octagonal edges?  45-degree rotations?  Cross-bars?  Oh my!

Wednesday, July 15, 2020

A Pox On You - Pox Box

Pox Box by Yavuz Demirhan

Pox Box PiecesWhat better time to pull out and play with the Pox Box than during a pandemic.  Why not open up a box with such a label?  How much worse can it get?  Pandora would be proud.

Maybe the word pox has some benign meaning that I’m not familiar with and to be fair, I decided to look it up.  I found 2 definitions for pox in the Mirriam-Webster dictionary: 1) A virus disease characterized by pustules or eruptions, and 2) A disastrous evil: plague, curse.  I’m not sure which of these 2 lovely definitions inspired the name of this puzzle, but it didn’t seem to be as bad as the name implied.

Pox Box Piece on
Top of Pox Box Box
Contrary to what you would think from the name, this beautiful puzzle is fairly innocuous.  It was designed by Yavuz Demirhan and made by Cubicdissection.  It consists of a box made from heavily pockmarked Birdseye Maple and 4 Sapele pieces that erupt like pustules from the face of the box (work with me here, I’m really trying to justify the name of this puzzle).  The Birdseye maple used for this puzzle is spectacular.  The splines that were added around the box are very nicely implemented using concave rounded bottoms.  The extra work done to add a veneered piece of wood to the tops of the pieces looks fantastic.  It hides the joinery that is normally visible on these types of pieces.

Birdseye Maple with Sapele SplinesYes, it’s a puzzle with a box and even has box in the name.  No, it’s not a puzzle box.  It’s a packing puzzle, so the objective is the remove the pieces and put them back in.  Although Pox Box has a level of 7.14.7, it is not difficult.  You’ll notice that as you take the pieces out, they all have the same shape.  That certainly makes things easier.  Not only that, but you will quickly realize that the pieces can only reside in the box in one orientation.  Wow!  The only thing that you have to do is find the order to put the pieces into place.

When the box is finally empty, you can see that there is a shape glued to each side of the box to frustrate the movement of the pieces.  I’ll refer to them as frustrations.  You will notice that they are securely glued to the inside of the box and you can’t take them with you.

Pox Box Alternate SolutionIn less than 2 minutes of fiddling, I had all 4 pieces in, except one of the pieces was slightly off and couldn’t be put in place.  It may look close to solved, but it’s not.  I took all the pieces out and then experimented with how each would be able to move given the frustrations and how the other pieces would block movements.  After a reasonably quick analysis, it was fairly simple to get them back into their proper locations.

If you are new to this type of puzzle and want to give one a try, this is a great one to start with.  Don’t let the name scare you off.

Wednesday, July 8, 2020

Hanging in Suspense - PackTIC V

PackTIC V by Andrew CrowellRecently, while I was on the phone, I pulled out the pieces of PackTIC V to keep my hands busy.  Does anyone hold a phone to their ear anymore?  Before I hung up, I had a complete 4x4x4 cube sitting on the table next to me.  Needless to say, I found this one easy and much easier than the other ACROSTIC puzzles that are rated as difficult.

Is PackTIC V really easy?  That’s not as easy to declare as you would think.  There is a tendency to equate the amount of time it takes to solve a puzzle with how difficult it is.  If you do enough of these, probabilistically, you’re eventually going to get lucky on making initial guesses for piece placements.  Many puzzlers have quickly solved a puzzle and declared it to be trivial only to be challenged in subsequent attempts.  Of course, the more puzzles you do, the luckier you are, and I’ve done quite a few of these TICs.

PackTIC V Pieces on a Tensegrity StructurePackTIC V was designed by Andrew Crowell and my version was 3D printed by Andrew.  It consists of 6 navy blue pieces that have to be inserted within a gray frame to make a cube with no visible voids on the exterior.  6 pieces is a lot for this type of puzzle and usually makes finding where the 6 pieces belong within the frame the major challenge.  However, for PackTIC V, I discovered where the pieces went rather quickly.

The predominant effort of solving this puzzle is getting the first 3 pieces in the frame.  The 4th piece requires a small rotation to place it in the frame and the remaining 2 are filler pieces that can be added or removed in a single move.

PackTIC V and Tensegrity StructureInserting any 2 of the first 3 pieces within the frame is trivial and when adding the 3rd, the other 2 always seem to get in the way.  Getting them in place requires determining the correct order of insertion and the rotations required to accomplish it.  All 3 pieces need to be rotated in the process.  Unlike some of the other ACROSSTIC puzzles, the rotations for PackTIC V are not that complex.  However, I did benefit by having thin fingers to accomplish one of them.  If you have a small version of this puzzle and large hands, beware.  Finding and executing this rotation is the hardest part of the solve and hidden pretty well.

The stand used to display the PackTIC V pieces is a tensegrity structure.  These have become popular lately as self-quarantining people are looking for things to do.  This one was made from STDs (yes, that’s standard tongue depressors) and string.  A side effect of the current pandemic will be a plethora of these homemade tensegrity structures.

This is the 7th post of the monthly Andrew Crowell Rotations and Obstructions Series - Turning Interlocking Cubes (ACROSTIC).  You can find the prior posts of the series here:

Wednesday, July 1, 2020

A Fantastic Puzzle, Believe It or Not - RIPley

RIPley by Andrew CrowellAndrew Crowell has been generating many hard-to-believe puzzle designs requiring elaborate rotations.  He started out with Turning Interlocking Cubes (TICs) and then migrated his rotational magic to Rotating Interlocking Boards (RIBs) and Rotating Interlocking Plates (RIPs).  RIPley is one of the first in the RIP series.

This particular copy of RIPley was made by Brian Menold at Wood Wonders and looks beautiful in Redheart with the double Maple splines.  Absolutely stunning and a great display piece!  Nothing is going to break those pieces apart.  I also didn’t realize until after I had the puzzle together that some of the pieces were pegged as well as splined.  Amazing!

For a board/plate burr, RIPley is not that difficult.  Please keep in mind that this is in reference to board/plate burrs.  If you haven’t done one before, it’s plenty difficult.  Having just worked on some others recently, I was able to put the unassembled pieces together in a single sitting.  In fact, I used this as a break from working on another one of Andrew’s RIPs.

RIPley PiecesRIPley consists of 6 plates that are comprised of 3 pairs of pieces.  Each pair is a different size, which greatly reduces the complexity.  In addition, one of the pairs has identical pieces, further reducing the complexity.  Two of the pairs have pieces that are parallel to each other but separated by a space, and the final pair has the pieces adjacent to each other.  It is trivial to determine the spacing between each pair from the pieces that they fit into.

The solution process was accompanied by the standard, well let’s try this - no that’s not right, recursive procedure.  It’s pretty easy to get 5 pieces together, whereupon you realize that getting the last piece in will take longer than getting the first 5 together - and that last piece you’re holding is almost certainly not the last piece that needs to go in (which it wasn’t).

Although BurrTools will not be able to solve this particular puzzle, there are not a lot of rotations required to solve it.  However, the required rotations come with a brilliant AHA moment sure to make you smile.  To get the full effect of the AHA moment, I recommend getting RIPley unassembled.