If you're adjusting for a different desk height, make sure the height matches the gap on the inside of the upper vertical wall (the one in contact with the desk border) instead of the thinner gap, once you add the headsets it will bend a little bit and pull the thinner gap wider (depending on print strength and headset weight).
Since the design is flat and a bit "hingy", I suggest using about 30% infill, my first print was 10% and it bent too much on the weight of the headset. I don't think you should use more than 30% either, because you need the clamp to widen a little bit to the desk height, but I haven't printed it over 30% so you can let me know in the comments.
Headset_Hanger.blend | 927.6KB | |
Headset_Hanger.stl | 43.3KB |