Ball and socket system, upgraded with a quarter turn twist lock on each ball joint to greatly increase pullout strength. My idea is to create a ball and socket system that is not only 3d printable but extremly strong and will not pop apart easily. This would be suitable for things like an LED lamp arm or heavy duty alligator clip where you don't want the neck popping apart. My original project was posted on hackaday: https://hackaday.io/project/5739-locking-ball-and-socket-gooseneck-system Update 5/17/15 New STL files posted on 5/17/15 - should work much better on printers with larger layer height / lower resolution