Designed a simple modular desk clamp for over the ear headphones. First attachment is the headphone hook, very simple. More attachments on the way. I recommend printing the stem foot at a higher infill such as 30-50% and using supports for the small overhangs on the main body.
(UPDATED) Shaved the threads on the nut and the stem foot so the tolerances are not as tight. Added to the file downloads for more user options!