Over-extrusion happens when the printer pushes out more filament than needed, leading to bulging walls, rough surfaces, and dimensional inaccuracy. Prints may appear blobby or have excess material squeezing out from layers.
Common Causes
- Flow rate too high — The extrusion multiplier exceeds 100% without proper calibration
- Incorrect e-steps — Extruder steps/mm is calibrated too high
- Filament diameter mismatch — Slicer expects thinner filament than what is loaded
- Nozzle temperature too high — Excess heat reduces filament viscosity causing overflow
- Print speed too slow — Slow movements allow extra material to accumulate
Recommended Fixes
- Calibrate extruder e-steps by measuring a 100mm extrusion and adjusting accordingly
- Reduce flow rate or extrusion multiplier by 2-5% increments
- Verify filament diameter with calipers at multiple points along the spool
- Lower nozzle temperature by 5-10°C
- Increase print speed slightly to reduce material buildup per segment
- Use a slicer flow calibration test print (e.g., single-wall cube) for fine-tuning