An acoustic guitar capo. It works pretty fine and is easy to print. There are four printed parts and two commercial parts. The spring is from the AnetA8 leveling system, a really common spring, so you can get it in your nearest 3D Printer store. The other one is a short M3 bolt.

The assembly is easy, you put the P2 part inside the P1, matching the holes, then pass the pin through it and close the other end with the washer and the bolt. Finally, add the spring.

If the pin does not work for you, you can replace it with a M6 bolt and nut. My printer was not working really well for this print, so the tolerances that i used in the design may not work for you.

I glued rubber of a bike tire tube in the surfaces that touch the guitar.