Undersides of unsupported geometry are rough, drooping, or curled upward into the nozzle path.
curling overhangsbridges fallingrough undersides
Ordered by how often each is actually responsible, not by how interesting it is. Work down the list.
Raise the fan — except on ABS/ASA, where more cooling causes layer splitting instead. Those materials trade overhang quality for structural integrity, and integrity wins.
Run a temperature tower and read the overhang band as a secondary criterion.
Slow bridge and overhang speed so each line has time to solidify before the next lands on it.
Reduce bridge flow, and verify the flow multiplier.
Calibration step: Calibrate flow ratio / extrusion multiplier →