Puzzle nút vòng 3D (3D Ring Knot Puzzle)

Anoter puzzle-piece my grandfather used to craft out of wood. Sadly, I don't know where this design is from, and i'm not really sure what to call it.

You'll need one “O”, and two “C” parts.

Solution:

I made the models in Fusion360. The drawing is entirely based on User Parameters:

STEP file is also included.