No Force Required – Gentle Interlock

It’s the season.  If you’re from Jersey, juno what I’m talkin bout.  And puzzlers will soon be reaping their own bountiful harvest of packages brimming with wonderful new acquisitions.  Last week was the momentous conjunction of events in the puzzleverse – Baxterweb, Cubicdissection Marketplace, Puzzle Paradise, and Mega Free Giveaways on the Mechanical Puzzle Discord (MPD).

The free giveaways on MPD have taken a life of their own and provide a means of repurposing homemade personal use copies of puzzles that would be impolite to sell.  Many are 3D printed and there has recently been a wave of some realized via LEGO.

Today’s puzzle is Gentle Interlock designed by Junichi Yananose from Pluredro.  Junichi has many more buyers than puzzles, resulting in his puzzles selling out in minutes or even seconds when they are released.  And he rarely has a second release of a puzzle since he is always working on the next design.  So he does his best at discouraging people from buying his puzzles.  In the case of Gentle Interlock, although there were prototypes of level 10 and 11, Junichi opted for the design with the lowest level - 6.  In his defense, he opted for this design stating that it had better playability.  As brilliant as all Junichi’s designs are, I took a gentle pass.

Fast forward to this year’s New York Puzzle Party (More PPing in the Big Apple – NYPP 2025)  where someone brought a copy of Gentle Interlock that gently tickled my brain and reminded me of this puzzle and how much I like burrs.  With that thought worming it’s way through my wormy mind, I eventually got around to pulling one from the replicator.

Gentle Interlock initially looks like a typical 6 piece burr but on closer inspection one end of each piece appears to be twice as large as expected.  This pushes the pieces away from the center thus providing more space to add bits where the sun don’t shine.  It also adds a nice bit of confusion since it orients what you may consider the center-facing side of the piece towards the side or even away from the center.

Since this puzzle was extracted from the replicator, it arrived unassembled.  Perfect!  The assembly is not trivial and it took me some time to work out where all the pieces needed to go and then how to assemble them.  Junichi certainly hit the playability goal he was aiming for.  However, I’m left wondering what the higher level designs would have been like.

Gentle Interlock was a fun puzzle and maybe one day, it will end up in a free bundle on MPD.

In Mint Condition – Dr. Bell's Curiously Warped Mints

Dr. Bell’s mind is jam packed with mind-blowing packings.  Why, sometimes he’s imagined as many as 6 impossible things before breakfast.  His warped sense of humor has now brought us a minty fresh take on edge beveled cube packing.

Dr. Bell's Curiously Warped Mints was developed by George Bell and used as his exchange puzzle for the 41st International Puzzle Part (IPP).  Each of the 6 pieces is 3d printed in a different color and comprised of 4 warped edge-beveled cubes.  The objective is to artfully cram all the pieces within an accompanying tin.  The type of tin that you would expect to find a nice assortment of mints to enjoy.  However, you are not expected to enjoy these mints.  The tin explicitly warns to not eat them.  So then why are they made with yummy colors like grape, blueberry, raspberry, lemon, lime, and licorice?

To get you started, some of the pieces are already in the tin and you only have to add the remaining 2.  Of course, I dutifully took all the pieces out and separated them before starting on my journey of 1000 missteps.

Being warped always seems like it should make things easier but it always feels like the opposite.  Examining the pieces, I noticed some interesting clues that I filed for possible later use and proceeded on without them.

The first step in these types of packing puzzles is to determine what type of packing structure is required, i.e., how the web cubes are oriented.  I struggled a while working on a packing orientation that would allow the cover to go on.  Then I unfortunately discovered something significant.  I was proud.  Or I should say the puzzle was proud of the lip of the tin.  I thought that this was a problem until I finally realized that when you placed the lid on, it did not rest on the top lip of the tin and providing a little additional space.  And after considerable effort I was able to pack all the pieces except 1.

It turns out that what I thought was a problem that wasn’t a problem was a problem.  Eventually I reread the goal and it said that the cover has to be screwed down, which screwed the packing approach that I was trying to accomplish.  I hadn’t even realized that the lid was resting on threads.  I now had nothing to be proud about.  Dejected,  I went back to the drawing board mumbling to myself, screw it ... screw it … screw it.

I eventually discovered another packing structure with a lower profile that would allow the cover to be screwed shut.  I also made heavy use of the clues that I had remarked on earlier.  At one point, I had a 3 subassemblies that looked like they would go together to solve the puzzle but would require coordinate motion to accomplish that.  Of course it would require coordinate motion coming from Dr. Bell.  However no matter how hard I tried, I was not dexterous enough to get everything lined up and moving like I wanted it to.  Curiouser and curiouser!  I eventually convinced myself that they would not go together using coordinate motion.  I was so close to victory, I could almost taste it.  Stepping back a bit, a minor tweak allowed me to assemble the pieces within the tin and screw it.

Once all the pieces are assembled, it truly resembles a tin of mints that are all stuck together and won’t come apart as if they were one giant enticing gobstopper.

It’s a clever puzzle and by the time I finally solved it I have to say that I ended up licking it.  Thanks Dr. Bell.

A Solid Challenge? – NotchedTIC

ARC TICs are extremely cool puzzles and most of the ones that I have solved have been 4x4x4 cubes.  One notable exception being MagellanTIC (Space, The Final Frontier - MagellanTIC), which is a 5x5x5 apparent cube and an awesome experience.  And now we have NotchedTIC, which is a non-apparent cube.

There’s just something so satisfying about solving a Turning Interlocking Cube (TIC).  However, it’s been a while since I’ve tackled a TIC by Andrew Crowell, aka ARC Puzzles {https://arcpuzzles.com}.  In 2020, I reviewed a different TIC by Andrew each month, with December’s being CagedTIC 1 (Ending With a Beginning - CagedTIC 1).  That post also had the links to the other 11 TIC posts for that year.  Although there were more ARC TIC posts, they weren’t as frequent and eventually trailed off.  How did that happen?  Well sometimes I get easily distracted. SQUIRREL!!!  Squirrel? Squirrel squirrel squirrelsquirrelsquirrel…

NotchedTIC is a 3D printed 6-piece 5x5x5 TIC designed by Andrew Crowell.  It gets it’s name from each edge having a missing voxel in the center.  And the puzzle arrived disassembled, which is my preference for attacking most burr puzzles.

The pieces to this puzzle fell into place fairly quickly.  Piece placement was obvious and pieces were able to be added 1 at a time with backtracking where needed to add a new piece.  Assembling the puzzle takes 28 moves with about a dozen of them required to add the last piece.  Along the way, 2 rotations are required but you don’t need to worry as they are not complex and obvious when needed.  In fact when taking the puzzle apart, the rotations will execute by themselves as pieces scramble to evacuate the TIC infested region.

I would classify NotchedTIC as more fun than challenging for experienced puzzlers.

Although I bought my copy second hand, you can buy the 3D Printable STL files for NotchedTIC and 5 other 5x5x5 TICs as part of a 6-puzzle set from Andrew’s site, ARC Puzzles.