While building a smoke extraction system, I found some jointed arms that were originally meant for holding smartphones and tablets, and I wanted to re-purpose it for holding a 120mm fan connected to some ducting.
The arms ended with ball-and-socket joints, so I designed this simple fan holder bracket with a ball joint meant to fit into the socket on the salvaged arm. I used OpenSCAD, and added named variables for the fan size (default 120mm), bracket thickness, fan screw-hole diameter, and the diameter of the ball in the ball-and-socket joint.
It's easy to modify for 40mm fans and other sizes, and I've included two pre-rendered .stl files for 120mm and 40mm fans with 25mm and 19mm ball joints respectively.
The author hasn't provided the model origin yet.