Temperature of filament, accuracy of extruder calibration, top layer extrusion width, poor quality filament, poor z axis calibration, partially blocked nozzle, a damaged nozzle, too few top solid layers, too fast top layer speed. There are probably other factors but these are all worth experimenting with one at a time, start with extruder calibration and top layer speed.
Simon Khoury
Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions