A few days ago I saw a puzzle that I recognized: a rope threaded through a large loop and a ring, with some large discs and beads. The puzzle is quite common; you have probably seen it. It is sometimes called the “Oliver Ring” puzzle, but I’m not sure what is the most common name or where it comes from.
I decided I wanted to have this puzzle, so I designed the parts in FreeCAD:
Then, I printed it on my 3D printer:
The puzzle worked well even though I didn’t know exactly which parts would need to fit inside the big loop for it to work. I used the image on this page as reference when designing the parts: rope puzzles. The ring part could have been much better – the first few layers of the print turned out pretty ugly. I might print a new ring, but otherwise I’m very happy with this small project.