Door Hanger for BodyMed Shoulder Pulley

My coworker has to do a certain kind of arm stretch to help with recovery from shoulder surgery.

They provided a pulley system for these excercizes which is designed to go over a door, with the barrel holding tight against the top of the door and door frame when closed.

He didn't want to close the door in his office, he wanted to hang it over an open door - and duct tape was insufficient to keep it up there.

This OpenSCAD design allows you adjust for the door thickness and gap between