Derived design with a trapped nut.
Blog posting:
marcuswolschon.blogspot.de/2012/11/gopro-to-nerf-gun-connector.html
License is CC-BY-NC-SA
So you may make one yourself and improve the design but not sell the design or made parts.
I'm trying to design things that serve a practical purpose.Mostly film making gear and parts for CNC machines.For my designs I try to also publish* the original file (usually Alibre/Geomagic)* technical drawings with dimensionsy...