Smart Effector hook

This hook is designed to hold the Smart Effector in a Think3DPrint3D Kossel XL Plus if it is too heavy to stay on its position after turning the printer off.
Since this is the case after [mounting big fans to the Smart Effector](https://www.thingiverse.com/thing:2909853 "Smart Effector mounts for large fans"), I designed this hook.
You need two M10 screws as counter weight in order for the hook to stay "open" by itself. When the Smart Effector is in home position you can press the hook down an