Summary

An classic brain teaser that will challenge you until you get that insight and think: "It's obvious! Why didn't I think of this before???"

Objective: separate the two arms without breaking them :-)

PS: for those who know it: this is a great Theory of Constraints (TOC) puzzle.

Instructions

Print 2 pieces, cut 4 small diameter (mine were 2.9mm) metal rods (trimmed steel nails, for instance) around 2cm long. Put one in each side making sure they have one end exactly in the inner hole limit. Put a piece of filament in the other extreme and glue it. Trimm the excess filament after glue is dry. Repeat for the other side. Metal rods should slide easily and freely.

Remember to do 2 pieces like so and then insert one on the other and after shaking it a little bit try to separate both :-)

UPDATE: see the PDF for a graphical illustration of the assembly instructions. Happy puzzling :-)

Good luck!

PS: if it is not clear let me know and I'll try to illustrate the assembly a bit more.

Holistic Puzzle, can you solve it?