Wednesday, September 30, 2020

Digging Through Puzzles - Artefacts

ArtefactsFinding a specific puzzle in a heap of puzzles is a puzzle in itself. I’m sure that most puzzlers that have crossed the 1000+ threshold have a sophisticated puzzle database that can be used to identify, describe, and locate any puzzle within a heartbeat. My sophisticated system, refined over several decades of puzzle collecting, is a 2-bin approach. New puzzles go in one clear plastic tub and solved puzzles go in another. Once a tub is filled, another is started. Unfortunately, there are probably more new tubs than finished tubs at this point in time. Since the tubs are mostly chronological, finding a puzzle involves locating the tub from the era that the puzzle was acquired or solved. I had the opportunity to test this system when I saw that Cubicdissection may rerelease Artefacts and I decided to take it out for this post.

In 2015, Packmaster Frederic Boucher entered a 2D packing puzzle in the Nob Yoshigahara Puzzle Design Competition.  This packing conundrum consisted of 5 wooden pieces and a metal rod that had to be packed into a square frame.  Each of the wooden pieces is made from two 1x 1x2 blocks.  Of course, the difficulty with these pieces is that they were glued up all wrong and are shifted by half a unit.  

The following year, Cubicdissection released a run of Artefacts in October 2016.  The Walnut frame was completed with a Baltic Birch bottom and Maple spines.  Along with the pieces made from Chechen, the puzzle is very handsome.  The steel dowel is much heavier than the other pieces and the black color makes it blend in nicely with the rest of the puzzle.

Artefacts has 2 challenges: 1) Pack the frame with all the pieces with the rod laying on its side, and 2) Pack the frame with all the pieces with the rod standing up vertically from a hole in the center of the frame.  Two challenges for the price of one!

Artefacts - Challenge 1

The Cubicdissection site indicates that there are 3 ways to pack the pieces in the frame with the rod laying down.  3 Ways!  Seems like you would have to work real hard not to stumble upon one of those solutions.  However, you may find yourself spending quite a bit of time trying to put the 5 Chechen pieces in the fame only to discover that the rod doesn’t fit.

Once you get a feel for how the pieces work together, it shouldn’t take too long to find one of the solutions.  After the first one is found, you then have to decide whether to look for the others.  Personally, I’m a one and done type of solver and once the first one is found I consider it solved.  If it has hundreds of other solutions, I generally don’t feel obligated to hunt every one down.  However, in this case there were only 3 and I’d be embarrassed to admit to not finding them all.

Finding all 3 solutions took about 3 times longer than finding 1.  The second was a little faster and the third was a little slower.  Of course, you need to make sure that you are not finding the same solution over and over again.  To help you with that, I did notice that the steel rod was in a different place for all 3, so you can use that as a way to identify the different solutions.  Another interesting fact is that only one of the wooden pieces occupies the same position for all 3 solutions.  So no, you can’t just swap a couple of pieces and expect to find another solution.

Artefacts - Challenge 2

For the second challenge, you place the steel rod standing up in the hole in the center of the frame and then add the remaining 5 pieces.  Standing that steel dowel on end means that it occupies less than half the space it did laying down.  So, it should be easier, right?  Not so much.  This one is not as straight forward as the other challenge and has only 1 solution.  This challenge took about the same time as finding a solution for the first challenge.

The tolerances on this version of Artefacts from Cubicdissection are very exact.  The 3 solutions for the dowel laying down are fairly loose in the frame but the solution for the dowel standing on end is snug letting you know which solution drove the frame size.  The steel rod also fits snugly in the round hole and won’t fall out if the puzzle is tipped.

If your interested in acquiring a copy of the puzzle for your own, keep an eye on the Cubicdissection Upcoming page.

Artefacts - Unsolved

Wednesday, September 23, 2020

Energetic Puzzling - Reactor Nuclear Packing Puzzle


Reactor by CoreMods

It’s about to go critical! The plutonium rods have been improperly stored, and a radioactive disaster is only moments away! Worse yet, some of the rods have begun to glow red-hot with radioactive decay. You must pack all the rods flush in the container, while balancing the ambient radiation, so that it can be sealed and transported to a nearby containment facility.

This is the message that greets you when you open the Reactor Nuclear Packing Puzzle from CoreMods.  Not only do you need to solve the puzzle, but you need to do it quickly.  No dawdling with those glowing rods.

Reactor is a squat gray box with a solid yellow bottom and a yellow cover with an ionizing radiation trefoil symbol.  Hopefully, your mail carrier won’t open the package for inspection.  The cover just floats on top and although it stays in place once the pieces are correctly inserted, it would be nice if it didn’t move when it was empty as well.

Reactor Pieces

The reactor chamber consists of a 5x5 grid of cylindrical chambers for storing 25 radioactive rods.  All you have to do is pack the supplied 25 radioactive rods into the reactor chambers.  Of course, there are some complicating factors that confound what should be an easy process.  The first is that some of the rods are connected to each other and you have to figure out how to create a 5x5 grid with the 7 aggregated shapes.  The second is that the rods are not all the same length and the chambers are not all the same depth.  Each come in 3 sizes and to make it more difficult, they don’t match in number, so you need to put some shorter rods in deeper chambers.  If that wasn’t enough, there is an unseen element that further impacts potential solutions.

Reactor Alternate Pieces

In addition to the original 7 Reactor pieces, there is a second set of 8 pieces that can be packed within the same box.  The second set has a more fluid, rounded look to them compared to the rectangular appearance of the original set.  It looks like the rods have actually started to melt.

So where did I hear about this puzzle and why did I get it?  At the NYPP earlier this year (A Puzzle Party in the Big Apple - NYPP 2020), a good friend mentioned that he was a member of an online puzzle community that I might be interested in.  Later, he emailed me an invitation link that I used to join the Mechanical Puzzles Discord group.  At the time that I am writing this, there are currently 776 members.  This group has many puzzle related channels and discusses pizza, pets, polls, and sometimes even puzzles.  Occasionally, members participate in virtual gatherings that include multiple people working on the same puzzle, usually a puzzle developed by one of the group members.

CoreMods Business Card

The last gathering started out as a Reactor party and morphed into a full virtual puzzle party with Reactor as one component of it.  We were lucky to have the Reactor developer, CoreMods, in attendance.  It’s a bonus when the designer is available to provide the background story behind the creation of the puzzle as well as future potential updates and other potential offerings.  

I solved both Reactor challenges during the Mechanical Puzzle Discord gathering.  Although CoreMods indicated that the second set was harder, I found it to be the easier of the two.  One other member that had completed both also agreed that he found the second challenge easier as well.  Regardless, neither of the challenges is going to stump anyone for a long period of time.  They are very approachable and can be solved fairly quickly with a little experimentation.

CoreMods Business Card - Back

CoreMods indicated that he has 2 other sets of pieces under development that are more difficult than the available 2 sets and provided some overall details on what to expect, which I won’t reveal here.  You’ll just have to wait for them to be released.

CoreMods produces the Reactor Nuclear Packing Puzzle and additional challenges on his 3D printer and you can find them on his CoreMods Etsy Store when they are in stock.

If you are interested in checking out the Mechanical Puzzles Discord, you can use this Mechanical Puzzles Discord Invitation.

Wednesday, September 16, 2020

Happy 16th! - Sweet Sixteen

Sweet 16

Happy 16th to you!  Yes, today is the 16th of September and we are celebrating with Sweet Sixteen by Jack Krijnen.  Jack developed this unique level 16 burr in 2002 and Cubicdissection released a run in July 2013.  You may recall that I originally pulled this one out and solved it at the end of last year, mistakenly thinking that the puzzle was Happy New Year by Johan van de Konijnenberg, which was the subject of the Happy New Year! post.  Like Happy New Year, Sweet Sixteen is made from Maple (5 pieces), Cherry (4 pieces), and Walnut (2 pieces) and the pieces have a very small bevel on the ends and none along the length.  

Sweet 16 - Pieces in Pile

The puzzle is not difficult to take apart and you can quickly make a pile of pieces from the puzzle.  After the disassembly, I left the pieces to lounge around on a shelf for a while to allow any neural connections created from the disassembly to decay.  After the last gasp of the final associated neuron, I attacked the assembly.  In actuality, I’m sure that I’m deluding myself thinking that I’m still capable of making neural connectivity changes that will survive the time between one breath and another.  I was going to mention something else here but I can’t remember what it was.

I waited until I had a good block of time to solve this puzzle and then sat down to tackle this bad boy and was astonished to have it assembled in less than 1 hour.  I was able to break the assembly down into several smaller steps that led to logical progression of assembling the pieces.  Of course, I could have also have been assisted by an extra helping of luck.  Sweet Sixteen has 1 more piece than Happy New Year (11 vs. 10), but I found it slightly easier to solve.  It is the perfect introduction to higher level burrs with more than 6 pieces.

Sweet 16 - Pieces

The remainder of this blog contains some information on how I proceeded to solve the puzzle, which may be spoiler for those planning on solving this puzzle.  Normally, I don’t like to post anything that can remotely be considered a spoiler, but since this puzzle has been released more than 6 years ago, I’m guessing that most copies in the wild on collector’s shelves won’t mind.  If you are just preparing to pull this one off your own puzzle backlog, you may want to stop reading here until you’ve solved your own copy.

The first clue is a gift.  The pieces were made from 3 different types of wood that correlate to the orientation of the pieces.  I suspect that the solution would have been significantly more difficult without this information.

Since there were only 2 walnut pieces, I started with them.  There are only two ways that they can be put together and more information was needed before determining the correct one which would hopefully become apparent when experimenting how they could fit within the 4 cherry pieces.

Sweet 16 - 5 Holes

When adding the 4 cherry pieces to the 2 walnut pieces, I quickly realized that the combination of pieces needed to leave an opening for each of the 5 maple pieces that go through the puzzle.  It became evident that the cherry pieces had to be divided into 2 sets of pairs to acquire the 5 holes but not how the pairs were oriented with each other or the orientation of the walnut pieces inside.

The design of the 5 maple pieces provides clues to their location within the puzzle.  With some inspection, it can be determined which piece is the middle piece, which 2 pieces are sandwiched by the ends of the walnut pieces, and which pieces are at the end of the 4 cherry pieces.  With that information, it is possible to orient the cherry and walnut pieces to accommodate the 5 maple pieces.

Sweet 16 - Two More Pieces to Go

It’s easy to add the 3 maple pieces that go through the cherry pieces, leaving only the 2 maple pieces trapped by the ends of the walnut pieces.  Disassembling the puzzle to the point where the 2 pieces can be added is straight-forward and quick.  Only one other piece had to be temporarily removed and then added back in after.

And there you have it.  A little insight into one way to tackle this particular 11-piece burr.  Hopefully there is something that you can use to when solving these types of burrs in the future.

Wednesday, September 9, 2020

Apparently Packing Puzzles - Corner Cube, Edge Cube, Angle Cube

Corner Cube, Edge Cube, and Angle Cube by Andrew Crowell

The latest fad for packing puzzles is to pack a few puzzle pieces into a box with one or more restricted openings such that the box appears completely full.  Usually, the pieces dance around each other within the box to acquire their final resting position.  It is surprising how many moves some of them take to solve.

The 2 most popular sizes for these puzzles are 3x3x3 and 3x3x2.  The solved appearance, making it look like a complete cube (or squat cube) within a box, has led to these puzzles being referred to as Apparent Cube Puzzles.  

These types of puzzles are very approachable and a great way to introduce puzzles to non-puzzlers.  They are clever little conundrums that can be enjoyed without requiring a large intricate attack strategy.

Completely Fill The Opening Notice

Recently, I had the opportunity to play with 3 of these types of packing puzzles from Andrew Crowell: Corner Cube, Edge Cube, and Angle Cube.  All 3 were 3D printed by Andrew in a variety of colors. All the cubes are of the squat 3x3x2 format and each of the puzzles has the name nicely debossed on the outside.  Everything is perfectly sized so that the pieces move extremely well within the boxes.  Occasionally, a piece will rotate out of alignment, but this is easy to remedy and not a real problem.

There has been some debate recently on whether it is obvious that the box should look completely filled instead of simply getting all the pieces within the box.  For those that don’t apparently get it, Andrew has addressed this issue by providing the following message on the inside bottom of the box: COMPLETELY FILL THE OPENING.  I’m sure that this will be followed by photos of pieces crammed in the openings and hanging out at all sorts of angles.

Corner Cube

 Corner Cube Pieces






Corner Cube by Andrew Crowell

Corner Cube consists of a brown box and 4 yellow pieces.  The opening of the box is in the corner and is unusual in the fact that it is not an integral number of voxels (think of voxels as the cubies used to construct the pieces).  It is 1.5 voxels in each direction.  I hope you weren’t thinking that the extra half voxel in each direction was to help you get the pieces in.  It’s there to provide a larger area that needs to be filled by the apparent cube within.

The 4 pieces look rather innocuous with 2 of them being simple di-cubes.  Don’t let that fool you however.  It takes 8 moves to get the first piece out once it’s assembled.  The solving procedure is very satisfying, and as with many packing puzzles like this, there is a lot of box tilting to get the pieces to move where you want them.  And yes, there is a rotation involved.  I hope you weren’t surprised by that.

Edge Cube

 Edge Cube PIeces






Edge Cube was made with a dark green box and 5 black pieces.  With the 2 dark colors, the contrast isn’t as striking as the with the other 2 puzzles.  I think that swapping the dark green with the lighter green of the Angle Cube might be a better choice.  

Edge Cube by Andrew Crowell

Like Corner Cube, the opening is 1.5 voxels in each direction.  The difference is that it is on the edge instead of the corner.  Are you grokking the naming scheme yet?

This one took me the longest to figure out even though it is the easiest one to repeat.  I had a good idea early on what the first piece to be removed was but couldn’t find a way to make it work. I tried a couple of other assumptions but in the end, I went back to the first assumption and finally found out how to make it work.  There is a very nice movement required and once that is figured out, the rest falls into place.  And yes, rotations are required.

Angle Cube

Angle Cube Pieces







Angle Cube has a shiny light blue box with shiny gold pieces.  Don’t you just love the sound of that - A box full of gold pieces.  Is anyone else thinking that there should be a treasure chest puzzle available sometime in the future.  I have to say that the filament used to make the gold pieces is awesome!  They really stand out.

The box for Angle Cube is missing an entire edge.  But to make up for taking a piece of the bottom out, a 1x1 triangular wedge has been added back on to the top and bottom to provide an opening with an angle.

Angle Cube by Andrew CrowellOnly 3 pieces to pack in the box.  Should be easy!  However, 7 moves are needed to remove the first piece when they are all in the box.  At this point do you even have to wonder whether rotations are required?  Of course they are!  And this one has the most unusual use of rotations in the series so far.

In summary, Andrews’s Apparent Cubes are nicely designed and clever.  I highly recommend them.  As a puzzle designer myself, I appreciate the effort required to come up with a good design and, for the Andrew’s Apparent Cubes in particular, the design considerations concerning the shape of the box openings.  

Wednesday, September 2, 2020

I Had This Feeling That I Was Going To Like This Puzzle - MystTIC

MysTIC by Andrew Crowell

After having done so many of Andrew Crowell’s TIC puzzles, I’ve developed this sixth sense that lets me know that I will enjoy the solving process, and so far, it hasn’t been wrong.  The latest of these is Andrew’s puzzle, MysTIC.  

MysTIC is a 4x4x4 Turning Interlocking Cube (TIC) cube consisting of 5 pieces.  It is 3D printed with the 2 main frame pieces printed in red and the other 3 pieces in green.  The colors are really vivid and stand out nicely.  As with all of Andrew’s 3D printed TICs, the name is conveniently debossed on the outside of the puzzle.  Very handy when you have dozens of these puzzles and are looking for one.
Right off the bat, I like the fact that there are no filler pieces.  In fact, it takes 10 moves to remove the first piece from the completed cube.  And some of those moves require rotations.  However, since I received the puzzle unassembled, those 10 moves define the completing sequence.

When assembling MysTIC, you just know where the pieces need to go.  It’s spooky.  You also get the feeling that there are going to be rotations required to assemble the cube.  It always amazes me how I can just tell that a TIC is going to require rotations.

MysTIC PiecesIt’s quite obvious how the 2 frame pieces go together when all you have is the 2 frame pieces.  It’s altogether a different matter when you have to get them together with the other interlocking pieces getting in the way.  With a little bit of investigation and some rotational magic, you end up with most of a cube and 1 piece left to put in place.  If it’s the correct piece, you are 10 moves away from completing the challenge.  It it’s not, a little bit of meditation is in order.

I have to admit, it took me longer than I expected to add that last piece.  For some reason, I was just not getting it.  So what if it takes 10 moves to complete the cube when adding that last piece and that 2 of them are rotational moves.  It’s not that difficult and I was chagrined to have not seen it immediately before the chanting.

MysTIC is another great puzzle design from Andrew Crowell and sure to awaken the inner cosmic puzzler in you.

This is the 9th post of the monthly Andrew Crowell Rotations and Obstructions Series - Turning Interlocking Cubes (ACROSTIC).  You can find the prior posts of the series here:

January: Puzzling DNA - GeneTIC

February: TIC, TIC, TIC - PackTIC II

March: Green Beer ‘ill Cure What Ails Ya - BioTIC

April: The Proper Way to Solve a Puzzle - PedanTIC

May: Will This One Really Be Better Than The Others? - SkepTIC

June: Space, The Final Frontier - MagellanTIC

July: Hanging in Suspense - PackTIC V

August: Fantastic 20+ Move TIC with an 11 Move Non-TIC Alternate Solution - PatheTIC