Surprisingly Difficult Puzzle




About: Making the most of things by making the most out of things.

This puzzle of interlocking hoops seems simple enough, but will leave most people scratching their heads.

There's no 'one weird trick' to solve it. This. Puzzle. Is. Hard.

Otherwise known as a Baguenaudier, Chinese Rings or a five pillars puzzle, this is a disentanglement puzzle in which a loop must be separated from the pillars.

I won't include the solution here, you will need to try it for yourself!

Step 1: Designing in Tinkercad

I used Tinkercad to make the design, which can be done using the basic shapes it provides.

After making one basketball hoop shape, you can copy and paste to keep the proportions the same, then adjust the height.

Use the ruler function to make sure the hoops are evenly spaced.

Once finished, export to an .stl fie for 3D printing.

Step 2: Preparing for 3D Printing

To prepare the .stl file for printing, load it into a slicing program like Cura.

This design requires a lot of support material for the floating rings, so make sure 'Generate support' or the equivalent is turned on.

I have attached the .stl file below so you can print it yourself.

Step 3: 3D Printing

The design took about 10 hours to print with the settings I used, most of which was the support material.

Remove this however you feel most comfortable (I prefer a screwdriver and a craft knife), but be careful of damaging the delicate posts or your hands.

Step 4: Finished!

Add a closed loop of string to the lowest hoop and you're ready to try out the puzzle!

Good luck and have fun.



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    17 Discussions

    wyndham carruth

    1 day ago

    yess, got it, i read the comments and realised it must be simple. had another look and it hit me like a train. cooool good instructable:)


    11 days ago

    Someone bought this same puzzle for me (made of wood) when i was little, and I actually solved it within ~30 min. I was addicted to puzzles at the time, so probably better than the average person, but I still think this puzzle is relatively simple. Anyways, still a fun puzzle, and the instructable is great!

    I think you can make the printing much more efficient if you just print the base with the poles on them, and separately print the rings with a partial hole in them to glue on the poles. Then you will save a lot of material printing it!

    2 replies

    Reply 11 days ago

    What I've found is when you give it to people, they thread the string through different hoops and pull on it expecting it to be free using just one move. Whereas it's actually about going through a process which takes logic and time. I think people who are into problem solving get on with this much better than most people.
    That is a great idea to save plastic! I will certainly do that next time and will amend the instructions if I find the time. Thank you!


    Reply 10 days ago

    Yeah, I can understand what you mean. In general, people that aren't used to thinking puzzles like these tend to look into 'intuitive' ways which usually lead to 'dead-ends'.


    11 days ago

    I have one made out of iron. I think that they are called Black Smith puzzles, or something like that. I won't tell you how to solve it either, but i will give you a hint. Think Tower of Hanoi. Puzzle people will know that puzzle.

    1 reply

    12 days ago

    I don't have a 3D printer, but love working with wood. I can see this made using circular curtain hangers and dowels with a wooden ball at the top of the largest dowel.


    14 days ago

    Wouldn’t it be much more robust if you made it out of steel and welded the loops on to posts and set them into plywood?

    3 replies

    Reply 14 days ago

    Yes, definitely. This more of project to get familiar with TinkerCad for me, but if you wanted a robust version that would be a great way to do it.


    Reply 13 days ago

    Yeh, I think I’ll try that in the absence on a 3D printer :-)


    Reply 12 days ago

    Same for me. I'll do it for Christmas gift.


    15 days ago

    just a standard step puzzle got to move the string up one level at a time


    19 days ago

    I was looking at it and realized how truly simple the solution really is. Very cool puzzle. Won't spoil it, but it looks like it would easily confuse a lot of people.