Hello,
I have huge trouble to have something nice on overhang even simple ones. I try to print a bolt and nut and i land with this crappy result. I try to slow down, redo a full calibration and so on, tighten the belt. I have still the issue.
Are you following the recommendations of the designer?
The parts are easy to print without support but they need a layer height of 0.12mm or smaller. Otherwise the outside of the thread flanks is not supported by the underlying layer. Besides that I recommend 3 walls, 4 to 5 tops & bottoms and 15% infill.
I’m referring to the screw thread; it has too much overhang. It seems the designer recommends specific parameters for the print. Did you follow their recommendations?