A typical indication for a this problem are gaps between the layers. This can be caused by partial under extrusion or by partial or completely skipped layers.
If you recognize that the extruder sometimes has a hard time to push the Filament trough the hotend, it´s maybe because your nozzle is to cold, try to rise the temperature by 5-10 degrees so that the plastic flows easier.
All FDM 3D printers use a small drive gear which grabs the filament and presses it against a bearing or another drive gear. This drive gear has sharp teeth that allow it to grip the filament. If the filament is unable to move, the drive gear keeps spinning and it can grind away enough plastic from the filament so that there is nothing left for the gear teeth to grab on to.
If this happens on your printer, you will usually see lots of small plastic chippings from the filament that have been shredded away. You may also notice that the extruder motor is spinning, but the filament is not being pushed in the hot end.
To solve this problem, you can try:
- to increase the nozzle temperature by 5-10 degrees so that the plastic flows easier.
- to change the printing speed, if the extruder tries to push the filament faster trough the nozzle than the hot end can melt it. Reduce it by 30% to see if the problem is resolved.
If the extruder slipped, make sure that the drive gear of the extruder is clean, because the plastic shreds can fill in the teeth of the drive gear. If this happens it is more likely that the drive gear slips again.
The most common filament diameters are 1.75 mm and 2.85 mm but there exist many more. But these measurements have different tolerances which can vary from 0.01 mm to 0.1 mm.
So, make sure you measure your Filament with a calliper on 4 to 5 points on the first meters and calculate the average diameter, before you use it.(Sum of measurements divided my number of measurements)
Use the calculated result, to set either the filament diameter or the extrusion multiplier to the correct value.
The most common method is to set the filament diameter to the standard measurement (1.75 mm, 2.85 mm etc.) and change the amount of extruded material over the extrusion multiplier.
(Attention: The extrusion multiplier is the percentage of extrusion for the specific diameter.)
Below you will find screenshots showing where to change the settings on Simplify3D, Cura and Slic3r.
To repair the print file might be necessary, if the you detect missing layers in the object. They can be caused by a damaged or incomplete file. There are a few options in your slicer program you can choose to repair these problems – see below: