It’s Simple Karma – Bram’s Hinged Cube

A long time ago in a land far away, an emerging puzzle designer attended an International Puzzle Party (IPP) with a collection of new puzzle designs.  Ensconced in a nook of the hotel lobby, this puzzle master wannabe commandeered a table to artfully arrange his new creations for attendees to play with - much to their delight. At one point, someone asked if a puzzle was difficult and after no considerable reflection whatsoever, the hapless designer pronounced that the puzzle was easy.  This seemingly innocuous response would come to haunt this young ignorant but well-intentioned individual for many years.  Watching that unsuspecting victim struggle over an extended period of time to save face made a lasting impression.  However, it was a lesson well-learned.  Puzzles are not easy or hard but one may be easier than another.  A puzzle that may be easy for one puzzler may be difficult for another.  Everyone gets inexplicably bogged down on an occasional puzzle.  There are many different types of puzzles and some puzzlers are naturally better at some types than others.

Fast forward to now where I am delighted to find myself struggling on a puzzle that others on the Mechanical Puzzle Discord (MPD) have declared SIMPLE!  This puzzle is Bram's Hinged Cube - not to be confused with the Hinged Cube designed by James Storer that made the rounds at last year’s IPP.

Nope!

Bram's Hinged Cube was designed by ... wait for it ... BRAM!!!  Bram Cohen that is.  It consists of 8 cubes that are connected with hinges so that they can be folded into a single 2x2x2 cube.  Bram said the solution is hard but various MPD members have countered that it is easy.  Personally, although it looks like it should be easy, I found it quite a challenge.

I solved James Storer's cube at IPP last year and found it a very enjoyable challenge.  And I jumped at the chance to try Bram's Hinged Cube when it became available this year.  After having solved both, I would consider Bram' s version more difficult although both are excellent.

With Bram's Hinged Cube, there was an easier solution but it was rendered invalid with the addition of faux hinges that attempt to occupy the same space in the easier assembly.  This leaves only the more difficult configuration as the only solution.  To be honest, it took me quite a while to determine how the connected cubes could occupy the 2x2x2 space in any configuration much less a second more obscure one.

Hot Off The Press!

After finding the faux solution multiple times, I finally manged to figure out where the cubes had to go.  Then I finally manged to find a folding sequence where it was not necessary to strain the hinges providing me with the solved 2x2x2 cube.  Then I finally managed to unfold it back to the starting position.  You would think that this last bit is a no-brainer shake-the-cube-back-out process but it’s not.  Of course, I even found myself forgetting where the cubes had to go in the middle of the folding process and had to start back at the beginning again.

Bram has generously made the puzzle available on Printables for anyone who would like to 3D printed copy of their own.  The stl file was created by Brian Pletcher as a print-in-place model.  One MPD member recommended using tree supports with the angle threshold set to 20 degrees and I found this to work amazingly well.  Print-in-place models still seem like magic!  You can download the stl file here - Bram' s Hinged Cube.