Over-extrusion (blobby, rough, oversized)
Too much plastic comes out: surfaces look lumpy, top layers are rough and parts come out slightly too big.
Also described as too much filament, blobby, lumpy surface, rough top, parts too big, overextrusion, bulging walls
Try these in order
Most likely and quickest to check first. Change one thing at a time so you know what fixed it.
Flow rate too high
- Calibrate the flow rate (extrusion multiplier) for each filament, usually between 90 and 100%.
- Check the filament diameter setting matches the filament.
Extruder steps per mm too high
- Mark 120 mm of filament above the extruder, extrude 100 mm, and measure what's left. Correct the steps per mm if it's off by more than a couple of millimetres.
Temperature too high
- Lower the nozzle temperature by 5 °C at a time, or print a temperature tower.