Three Caterpillars

How many caterpillars does it take to make a butterfly?  No clue!  But apparently, it takes more than 1 to make a symmetric shape.

Three Caterpillars is a 2D symmetry puzzle designed by Alexander Magyarics.  You may never guess that it consists of 3 caterpillars that need to be arranged to make a symmetrical shape.  The type of symmetry is not specified.  And if that is not enough, each pair of pieces can be used to make a symmetric shape as well.  Four challenges for the price of one.

The pieces are 3D printed and the heads are a different color than the rest of the body so you know which way they are looking.  The colors have no relationship with the symmetry constraints unless I completely misjudged it.

The 3 challenges for making a symmetrical shape with 2 pieces are not that difficult and make for nice warm-up to the main challenge.  The 3-piece challenge is a bit more involved than the 2-piece challenges but I didn’t find it as tough as some of Alexander's other symmetry puzzles.

One Match Left

I recently had the opportunity to acquire some 3D printed hand-me-down puzzles from a kind soul on the Mechanical Puzzle Discord (MPD).  Among the nice selection of puzzles was a copy of One Match Left.

One Match Left is a 3D packing puzzle designed by Jorgos Anastasou.  It consists of 3 pieces that need to be packed within a cubic tube.  Both ends of the tube are open and there are 2 protruding obstructions on the inside that keep the pieces from simply falling out.  One is single voxel and the other is a double.  Two of the pieces look like burr pieces and the third is in the form of a match.  The version that I received was printed with extra attention to detail to make the match piece look like a match with a white body and black tip.

This puzzle is one of Jorgos’ easier puzzles and not difficult to solve.  Determining how the 2 burr pieces are oriented within the box and where the match goes is straight-forward and once you have that, putting them all within the tube is a quick process.  One Match Left is a great introduction for this type of puzzle and good warm-up for tackling more difficult puzzles of this type like 4 In Frame (Foreign Fame - 4 In Frame) or Wheel Lock (An Impediment to Rolling Along - Wheel Lock).

 

Gears

Not being much of a gearhead, I was a little apprehensive of tackling Gears designed by Hirokazu Iwasawa (Iwahiro).  It is a 2D restricted-opening packing puzzle made by Constantin Puzzles that Iwahiro used as his exchange puzzle at the 41st International Puzzle Part (IPP).  It consists of a frame with a hinged door on the side that can be opened to allow gears to pass through.  There are 9 gears in all.  2 of them are fixed in the center of opposite sides of the frame and can rotate freely.  The remaining 7 loose gears are the same size and have the same number of teeth as the fixed gears except for 1 that lacks teeth.  The frame also has a large opening in the clear acrylic top in the shape of an I to provide a means of manipulating the pieces when they are inside.  Lastly, there are a couple of pointy bits in the frame to throw a wrench in the gears.

The objective is to add all the gears to the frame and close the door.  I started to putter around with adding gears but it took a while to get the gears turning, in my brain that is.   It all starts out easy enough, but as more gears are added, they need to rotate as they pass through confined spaces eventually leading to gears disagreeing on which direction they should be rotating.

Shifting my brain into high gear, I finally settled on where the toothless wonder needed to be.  Of course I tried all the other places to rule them out for certain.  Even then it was not obvious to me how to proceed.  Eventually, I shifted gears and tried something a bit more complex that set the machine in motion and allowed the lid to close with all the gears inside.  A very nice AHA moment.

Holey 2D Symmetry, Batman – Rising Sun & LUV Potion

In a departure from the usual 2D Symmetry puzzles, I present Rising Sun and LUV Potion.  Not only do the pieces have to be arranged to make a symmetric shape but the holes in the pieces must support the symmetry as well.  Both puzzles were designed by Frederic Boucher and made by Nothing Yet Designs in acrylic.  And neither puzzle indicates the type of symmetry required to solve it. 

Rising Sun

Rising Sun consists of 2 pentominos and 1 tetromino, each with a circular hole through it.  I’m assuming that the holes are not simply decoration but there to single out a unique solution from multiple other potential solutions that may exist if the holes were not present.  However, I don’t recall finding any other symmetrical shapes disregarding the holes.  Although I didn’t find it too difficult, it was more challenging of the two.

LUV Potion

Similar to Rising Sun, LUV Potion consists of 2 pentomino pieces and 1 tetromino piece but the holes are shaped like hearts giving them directionality.  As with most 2D symmetry puzzles, the pieces don’t want to cooperate and seem downright unfriendly.  However, this is understandable since each lacks a heart.

Instead of making things more difficult, the directionality of the hearts provides additional information revealing the type of symmetry needed to solve this puzzle.  This turns out to be quite useful, making this puzzle one of the easier 2D symmetry challenges.  It’s not that difficult to find the solution among the many symmetrical shapes you can make disregarding the hearts.

I’m sure that it’s challenging to determine the optimal locations for each heart when designing the puzzle.  It would be interesting to see the 8 previous prototypes.

If you would like to get your own copies of Rising Sun or LUV Potion, Nothing Yet Designs has these puzzles available as well as other puzzles from Frederic Boucher and 2D symmetry puzzles from other designers.

No Problem Puzzles, Update #10

No Problem Puzzles provided over 100 amazing puzzles designs for the community between November 2020 and April 2023 until the tragic passing of Symen Hovinga on 7 April 2023.  Theo Geerinck, the other half of the No Problem Puzzles duo, decided to graciously allow the puzzle designs to be made available to the puzzle community for anyone to print their own copy to keep the legacy alive.  Mr BurrTools himself, Andreas Röver, is currently in the process of verifying and publishing the stl model files over the next several months.  These are being made available on the Printables site under the No Problem Puzzles collection.  Another contributor, Crab on Printables, has also tweaked some of the models to improve them.

This post continues the review of the No Problem Puzzles as the models are being released.  Since the last review (No Problem Puzzles, Update #9), more No Problem Puzzles have become available.  All level of difficulty ratings are from the puzzle descriptions and are on a scale of 1 to 5.

Drawbridge

Drawbridge is a 3D packing puzzle with 3 tetracube pieces that need to be packed within an articulated frame.  2 of the 3 tetracubes are identical.  The objective is to make a 2x2x3 cuboid with the 3 pieces pieces inside the frame, which is large enough to hold a 2x2x4 cuboid.  The frame consists of 2 joined parts consisting of a base and a top that can rock back and forth.  The frame has a lot of nice added detail to add character such as brick siding, decorative X-braces, and triangular patterned holes.

At a difficulty rating of 3, it makes for a nice challenge.  I tried various methods to insert the pieces past the tilting top until I landed on the correct one.  In hind-sight, the solution is more straight-forward than most of the ones I attempted.  Part of that was applying things I had seen in other puzzles but didn’t end up applying here.

Nest Box

Nest box consists of 5 polycubes that need to be packed within a box shaped like a bird house.  The house is complete with a perch, round doorway, cathedral ceiling, and a chimney. 

The only objective given is to pack the pieces within the box.  Even though this is a level 3 puzzle, I popped them in within minutes.  My rather inelegant solution lead me to believe that I was missing a constraint or two.  Considering that my solution had a piece stuck in the chimney, I decided to try finding a solution that had the chimney unoccupied.  And after some additional effort, I had them packed with the chimney unoccupied.  Was that the solution?  Maybe not since I used a rotation and I was beginning to suspect that if the word rotation is not used in the description then it’s not to be used.  Taking once last shot, I finally came up with a solution that packed the box with the chimney empty and without using rotations.  Whew!  BTW – the rotational solution was rather clever but difficult to undo.

Tumbler II

Tumbler II consists of 3 pieces that need to be packed in a 3x3x3 box with a bar across the middle of the open top that can rotate to each side.  And there are poke holes on all the other sides of the box including the bottom.  It has a difficulty level of 3.5.

I really should read the directions before solving these puzzles.  It requires no rotations and the 2 open rows on the top should be filled.  So much for tumbling the pieces in the tumbler.  The requirements removed some of the cool tumbling moves that I found.  In my defense, I have an expanding collection of these puzzles unsolved on my shelf and casually take them down to solve without going online and looking at the directions.  Perhaps I should consider writing the constraints down since the puzzle is really incomplete without them.

The solution to this one was nice and sneaky.  It took awhile before I groked the sneaky bit but after that it was quick going.

Slideshow

Slideshow is a level 3, 3D restricted packing puzzle with 4 pieces that need to be packed in a box with a sliding top.  However, the sliding top is at an angle and is not removable.  Unlike other puzzles, I knew exactly what to do here and proceeded to assemble the pieces where they needed to be.  Oddly enough, they couldn’t quite get there so I proceeded to tweak the assembly.  And I continued proceeding to proceed until I finally lighted upon a move that allowed me to further proceed.  At this point, I knew the movements needed to solve the puzzle but that’s only half the problem.  The other half is being able to accomplish those movements in a restricted space without access.  I’d like to point out that there are no poke holes in this puzzles since slideshows require darkness.  I finally manged to solve this one with my patented hopeful shaking technique.  But not to worry.  Unpacking is much easier than packing.



If you don’t have a 3D printer, you can obtain copies of No Problem Puzzles from Nothing Yet Designs based in the US or the PuzzleguyStore based in the EU.

Windows 2

Windows 2 is a 5x5x5 Turning Interlocking Cube (TIC) designed by Andrew Crowell.  This bicolor puzzle consists of 6 pieces that form a white shell around a blue 3x3x3 apparent cube in the center.  Each side of the white exterior has 4 windows that allow you see the blue core.

When I pulled Windows 2 out to work on it, I only meant to sit down with it for a couple of minutes to figure out where the pieces went.  However, I was having such a good time that I ended up solving it before getting up.  Rather a bittersweet finish since this was the last 5x5x5 TIC in my backlog.  Luckily for me, I think I still have some 4x4x4 TICs that got pushed further back into the back of the backlog.

Initially, Windows 2 reminded my of Templars Cross (A Spirited Journey – Templars Cross) with the corners still intact.  However, I found it quite a bit easier to solve.  The last 2 pieces weren’t nearly as difficult to get in place and pieces just seemed a bit more accessible for manipulating.  If you are planning on doing both (recommended), I’d suggest starting with Windows 2 as the warm-up.

If you want to print your own copy of Windows 2, the model files are available on ARC Puzzles as part of the second volume of 5x5x5 TICs.

RMF

RMF is a 3-piece 2D symmetry puzzle designed by Alexander Magyarics.  Each piece consists of 3 squares but 1 square of each piece has been cut in half diagonally and the halves have been separated.

The goal is to place the pieces together to make a shape that you can rotate, mirror, or flip and still end up with the same shape.  Only one of those operations is required but you are not told which one.  And there is only 1 solution.

You can try to devise a robust mathematical framework for analyzing these these types of puzzles but it’s really more fun to use them as fidget puzzles.  They’re perfect for zoom meetings.

This one didn’t take me as long to solve as some of Alexander’s other puzzles I recently blogged about but I still appreciate how devious the solution is.  Maybe something is sinking in.

I wasn’t sure where the name RMF came from but thankfully AI cleared it up for me:

The RMF symmetry puzzle is named after its designer, the puzzle inventor Alexander Magyarics.  The letters represent the initials of his first name (R... [Alexander is often known by his surname]) and the M and F indicating Magyarics Family or a similar personal arrangement.

If you are interested in acquiring a copy, RMF as well as many other 2D symmetry puzzles from Alexander and other designers are available at Nothing Yet Designs.