If you’ve been experiencing that not enough filament is being extruded through the nozzle during printing, which results in print objects with unexpected holes or missing layers, it’s most likely due to one of two things:
A) The filament gear. If your printer’s filament gear (which pulls the filament string into the printer) is dirty, worn or mounted incorrectly, it can lead to under-extrusion. Look at the first half of our instructional video to see if your filament gear could be the reason for the under-extrusion you’re experiencing.
B) The nozzle. It is most likely the filament gear that is causing the issue – so do NOT start cleaning the nozzle before you have tried to change the filament gear. It is rather complicated to clean the nozzle and incorrect assembly can make the problem worse. If you have changed the filament gear, checked that the system is assembled correctly and there is no leftover filament in the extruder system, but there is still not coming enough filament our of the printer then continue to follow the second half of this video. Follow the video carefully and make sure to assemble the system exactly as in the video.