Rafter hangar

This ultra-simple hook system has been slick to hang things from the rafters of my shed.  I'm releasing the source code (under Creative Commons - Attribution - Noncommercial License) so anyone can modify it.  The loop idea has proven to be extremely strong, even in PLA, due to the extrusion orientation.  The hook will be the weak point.

Anyone could design this in a short time but it may be interesting for someone who wishes to see what a parametric FreeCAD project looks like.

Exported in STEP only because I couldn't be bothered.  Source available, for those who wish any other format.

I used PLA, no support, and melted it out at best possible speed with semi-moist filament.  For the hook, I used 4 top layers, 4 bottom layers, 4 perimeters.