To use, thread your headphones through the hole until the earpieces rub up against the winder. You can take it from here, I think.
Printed with a 0.4mm nozzle, 3 perimeters or 1.2mm walls. support for any angle over 50 degrees.
You'll need to scale to your needs. I chose 80mm length.
The code's pretty messy, but feel free to run this through customizer. I got lazy trying to match up what I'd set each variable to use. Also, sorry about the magic numbers :/