I've designed this corner gusset in order to fix the clothes hanging bar (20mm diameter) because of the weight of some clothes, the bar managed to tilt and the whole hanger was about to fall down.
As you can easily see, there's a difference between the CAD model and the printed model, because I've printed the 1st version than for the 2nd version I've tried to make the model a little bit light-weight, because my printer made v.1.0 in about 11h11min @ 0.2mm layer height, which is crazy.
Anyways, the printed gussets are attached to the bars using zip ties(5mm wide type).
Hope you'll find this useful. Good luck!