3D Printing Filament Grinding: What Causes It & How To Fix It

3D Printing Grinding Filament

(Image source: Anycubic official user group)

Filament grinding is a common issue in 3D printing. If the extruder motor of your printer emits a clicking sound, it indicates that the gears of the extruder are probably grinding or stripping your filament. Grinding marks and dents can be left on the surface of your filament, and filament debris may accumulate around the extruder. When this problem occurs, it's a sign that your extruder is becoming damaged and non-functional if not resolved promptly. But fixing it is not a tough nut to crack. Firstly, you need to clearly understand its causes, and then troubleshooting will be direct and straightforward.

What Causes 3D Printer Filament Grinding?

Filament Grinding

Inside the extruder, there are two gears that push against each other, and the filament passes through between them. In this case, the gear cogs can grip the filament and feed it to the hotend. However, when this force becomes excessive on the filament between the gears, it can lead to filament grinding issues. Additionally, neglecting to clean the nozzle and extruder that can result in the buildup of plastic residue, which can also contribute to print failures. The following five points may be the cause of filament grinding.

  • Extruder tension is too tight.
  • Printer nozzle is clogged.
  • Retraction settings are wrong.
  • Printing temperature is too low.
  • Printing speed is too fast.

How to Stop 3D Printer Filament Grinding

1. Loosen Extruder Gear Tension

Adjust Extruding Tension

The inappropriate extruder tension is often an overlooked quality issue, for example, excessive tension easily leads to filament grinding and breaking in feeder, while insufficient tension can result in under-extrusion problems. Adjusting it is simple, just rotate the screw or knob on the extruder to control the tightness of the spring and gear. You can find a detailed tutorial on how to calibrate extruder tension in this blog post.

2. Keep Your Printer Nozzle Clean

Clean 3D Printer Nozzle

Clogged nozzles often lead to terrible problems like filament grinding. If there is previous printing material residue inside the nozzle, the extruder's feeding rate may exceed the nozzle's working speed. This can result in difficulty pushing the filament through the extruder, so clicking noise and filament grinding may happen along the way. Keeping the nozzle clean is essential after printing every time, especially in the case of print failures. But this is not a challenging maintenance task. You can use a needle and brush to remove the debris from the nozzle. For detailed guidance, check this article on how to unclog a 3D printer nozzle.

3. Reduce Retraction Speed and Distance

Retraction Settings

The retraction settings in the slicer can significantly reduce 3D print stringing and oozing, but the wrong configuration can lead to 3D printing filament grinding. If you have activated these settings in the slicer, make sure the value you have dialed in is correct. When it is set too high, the extruder will pull back the filament from the hotend too aggressively, causing the extruder gear to repeatedly grind the filament. This requires you to inspect and test the retraction settings, and lower them if necessary.

4. Increase Hot-end Temperature

Print Temperature

There are various types of filaments, each with its own optimal temperature range requirements. For example, the most popular filament - PLA usually requires a hotend temperature between 180 and 220°C, while ABS typically requires a temperature between 230-250℃. Therefore, ensure that the printing temperature you configure is appropriate for the material you use. If the temperature is too low, it is advisable to increase the hotend temperature by 5-10℃ and try printing again.

5. Reduce Printing Speed

PLA clumping at extruder

If the print speed is too fast, the extruder motor can drive the gear to rotate rapidly, leading to grinding issues. Moreover, soft filaments are easily prone to get stuck into the extruder, and the filament not coming out of 3D printer will happen. It is recommended to set the print speed at a default speed from the printer manufacturer and see if the issue is resolved.