The Brain Teaser: Full Solution

This is part 6. After the fold I show the complete solution for assembling The Brain Teaser.

The Brain Teaser: Assembly hint

This is part 5. After the fold I reveal one hint -- the blind spot that initially prevented me from assembling the puzzle given the manufacturer's solution.

The Brain Teaser: The manufacturer's solution

This is part 4. After the fold, I show the solution provided with the puzzle. If you also received the puzzle in its original packaging, you should already have this solution page.

Disassembling The Brain Teaser

This is part 3. After the fold, I show how to finish disassembling the puzzle.

Unlocking "The Brain Teaser" puzzle

This post is part 2 of several posts documenting the solution to the ECO Game Brain Teaser puzzle. For the benefit of anyone who only wants hints, in this post and the following most of the post will be 'after the fold'.

The ECO Game "Brain Teaser REMUE-MÉNINGES" wooden puzzle

Update: If you arrived here via a web search, you might want to see all posts about the puzzle. Click on this link to see the brief form of all six posts in reverse order, showing this post last and the final complete solution first. Don't worry if you are only looking for hints, the brief form of the posts don't reveal any solutions. I've written the posts such that you should be able to get only the hints you are looking for, when you are ready for them.

This is part 1 of six parts.

Santa left a fun wooden puzzle in my stocking this year. Whatever packaging the puzzle was in was recycled with all of the other packaging and wrapping paper that accumulated that morning. All I have now is the puzzle itself, and small slip of paper that has the solution to the puzzle. That slip of paper identifies the puzzle as The Brain Teaser / REMUE-MÉNINGES, with brand names ECO GAME and Relaxus. It provides the domain name www.relaxus.com, but I have searched that site and could not find any links to the puzzle. I conjecture that Relaxus is only the U.S. distributor and that the original manufacturer is French. If anybody reading this knows more details please leave a comment.

The puzzle looks like this:

Only one view of the puzzle is shown above but you should be able to get clear picture of the overall structure from the one view because of its many symmetries. There are three rectangular blocks with square cross sections that form a natural set of xyz axes. Rotate the puzzle 90 degrees about any of the three axes and you get the same shape.

This puzzle (like others in the genre) is two puzzles in one. First, you have to solve how to disassemble the puzzle. Then, you have to solve how to reassemble it. Disassembly is by no means trivial, but I was able to figure it out after a couple minutes. There is one trick to unlock the puzzle and then it almost falls apart. When I had figured out the trick, I impulsively decided to quickly disassemble the puzzle completely without making any attempt to understand the topology. My thought was that I wanted to tackle the second puzzle without 'cheating'. In the back of my mind I knew that if I got stuck, I could just use the solution page.

Later that day I sat down and spent about 20 minutes trying to solve the puzzle. It became clear that it wasn't going to be easy. I set it aside, and then spent another 20 minutes later in the evening, and then again the next day. I explained to my 5 year old daughter that for some problems I need to tackle them over several days and let my brain work on the problem while I sleep. By the morning of December 27th, I had 'slept on' the puzzle for a couple nights, but was still basically stuck. I debated with myself whether to give it another couple days, but decided to give in and take a peek at the solution page.

It turned out the solution page was pretty skimpy. I spent a few minutes trying to follow the instructions only to find myself reaching a dead end where the instructions seemed to be wrong. It took me another 10-15 minutes of head-scratching to figure out what was missing from the instructions that allowed me to go astray. During that time I did a quick web search and didn't find any links to hints or solutions. Since I have a little spare time this week I decided document the solution. I will attempt to structure this documentation so that anyone who is just looking for hints can get them without being exposed to the complete solution. After the fold for this post I'll provide one hint for anyone who hasn't figured out how to disassemble the puzzle.