Is your 3D printer extruder clicking? Here is how to fix it

FDM 3D printing is certainly not a silent process: it is perfectly normal for your 3D printer to whirr and even buzz as the printhead moves and filament is extruded onto the build plate. In fact, desktop 3D printers can produce up to 50 decibels of sound when in operation—similar to the amount of noise a relatively quiet fridge produces.[1] However, if you start to notice clicking sounds that seem to be interrupting the regular hum of your machine, then you could be dealing with a problem.

Unfortunately, if your 3D printer extruder starts to make a clicking noise, it’s not just your ears that will be bothered. Clicking is indicative of a bigger problem, which can compromise the quality of your 3D prints. A clicking extruder can be a sign of filament extrusion inconsistencies, such as under extrusion or a clogged nozzle.

What causes extruder skipping and clicking

The first step to fixing a clicking extruder is to figure out what’s causing it. In general, the extruder will start clicking or skipping if the extruder gears—which are responsible for feeding the filament into the hot end—struggle to do their job. The clicking noise itself comes from the stepper motor, which has to use greater force to turn the gears, and then compensates for the added force and subsequent pressure by skipping back. 

There are several culprits that can cause extruder gear issues. We’ll take you through the main ones and how to solve each one.

Low temperature

Temperature plays a huge role in the 3D printing process: setting the print temperature too high can make the filament melt too quickly, causing issues like oozing and stringing. If the print temperature is too low, the filament won’t melt at a sufficient rate, which can lead to nozzle clogs. If the nozzle becomes clogged, the printer extruder will struggle to feed the filament through, which can ultimately lead to skipping. 

Fortunately, there is an easy fix for this problem: all you have to do is gradually raise the print temperature—by about 5 °C—until the filament starts to flow more smoothly. It is also important to remember that each type of filament has an optimal print temperature. So if you’re working with ABS after having printed PLA, you’ll need to adjust the print settings accordingly. 

Recommended reading: ABS print temperature considerations

Low nozzle position

When temperature doesn’t seem to be the issue but you are still experiencing extruder clicking from a partially clogged nozzle, nozzle height could be the reason. If the nozzle is positioned too close to the print bed, the filament won’t extrude onto the build surface properly because the nozzle will effectively be squishing it. Not only does this cause under extrusion for your prints, it also causes nozzle jams because the melted filament sticks to the outside of the nozzle. 

If you notice the combination of a clicking extruder and filament buildup on the outside of the nozzle, your best bet is to level your 3D printer bed. Some 3D printers have automatic bed leveling, but for those with manual machines, the easiest way to level your bed is to use a standard sheet of paper. Move the nozzle to one corner of the build plate and place a piece of paper under it, lower the nozzle until it just touches the paper (the paper won’t slide out, but will be able to move). Repeat this for every corner of the build surface. 

Clean your nozzle inside and out to ensure a consistent filament feed rate and minimize the risk of clicking.

Nozzle blockage

If your 3D printer has become clogged for whatever reason, it can cause extruder clicking. If this happens, you will have to find the source of the blockage—such as adjusting the temperature—but you will also have to unclog the nozzle. If you’re dealing with a partial clog (i.e. some filament is still flowing through), you can use a cleaning filament to remove the clog or a wire brush to clean filament buildup from the surface of the nozzle. 

If the nozzle is showing signs of a full clog, there are a few techniques that help to remove the blockage. You can insert a thin wire or needle (smaller than the diameter of your nozzle) into the heated nozzle to break up the filament. This will allow the debris to flow out and clear the block. 

Another popular method to unclog a 3D printer nozzle is the cold pull. To do the cold pull, heat up the 3D printer extruder (to between 200-250 °C depending on the filament) and push a length of filament into the print head. You’ll then let the print head cool until the filament is solidified. After that, reheat the 3D printer to a lower temperature (115°C) and when it reaches 90 °C, rapidly yank the filament out of the extruder. The filament should have bonded with the buildup and been pulled out along with the filament.

Recommended reading: How to Clean 3D Printer Nozzles and Prevent Clogs

PTFE tubing failure

Bowden tube 3D printers rely on a PTFE tube to direct and feed filament into the print head. When the tubing system is working correctly, the filament should move through the tube seamlessly, without any friction. Extrusion problems can arise, however, if there is too much friction inside the bowden tube. 

There are a couple things that can be causing this friction. For one, a bowden tube that is too small for the filament diameter. In general, the bowden tube should be just marginally larger in diameter than your filament: you want it to move smoothly through the tube, but you also don’t want too much space for the filament to flex and bend. Secondly, any debris that builds up inside the tube, such as dust, can increase the friction. This can slow the filament down and create a buildup of pressure in the extrusion mechanism, leading to clicking. 

To ensure that the bowden tube is not causing any extrusion issues, clean it regularly by removing it from the 3D printer and pushing a small piece of cotton or sponge through the length of it using filament. If that doesn’t solve the friction problem, and your bowden tube appears to be dented or bent, you can always replace the tube.

Recommended reading: Direct Drive vs Bowden Extruder for 3D Printing

Friction build up inside a bowden tube can slow filament down, causing stepper motors to overcompensate and skip.

    Extruder spring tension

In the FDM 3D printing process, filament is propelled through the extruder with the help of either a single gear or dual gears. The movement of the gears is powered by a stepper motor, but the extruder also relies on a certain degree of tension to ensure that the gears make contact with and grip the filament in order to feed it into the printhead at a reliable pace. This tension is created by the extruder spring.

If the extruder spring tension is too high, the gear teeth will press into the filament too much, causing filament deformation. The high tension can also impede the feed rate of the filament, which in turn causes the stepper motor to exert more force and even start to skip. The skipping motor is what creates the clicking sound in your extruder.

If the tension of the spring is too low, the extruder gears won’t sufficiently grip the filament, which will require the extruder to use greater force to feed the filament into the printhead. The added friction can lead to problems like filament degradation and grinding noises. [2] All that to say, finding the correct degree of tension for your extruder spring is vital to achieving the highest quality prints. On most 3D printers, spring tension can be adjusted using a screw or knob. You can always start by loosening the tension completely and gradually tightening it until clicking stops.

    Idler wheel too tight

This troubleshooting is applicable to single-gear extruders. The idler wheel, or idler roller, is a round bearing that helps to guide the filament along the single gear into the printhead. If the idler wheel is tightened too much, the result will be similar to high spring tension: the gear will start to crush the filament, which can lead to extrusion troubles and stepper motor skipping. 

You can tell your extruder’s idler wheel is well calibrated by checking the thermoplastic filament as it is threaded through. Small gear tooth marks on the filament’s surface are a good sign: they show the gears are making sufficient grip to move the filament at pace. If you notice any crushing or deformed filament, loosen the idler wheel tension slightly. This can help reduce the risk of clicking and failed prints.

    Faulty extruder motor

Another possible cause for extruder clicking is the stepper motor. If the stepper motor is poorly calibrated or is not connected to a reliable power source, it can result in filament feeding inconsistencies and, consequently, clicking. This issue is rarer than the aforementioned ones, so try adjusting your settings before making major hardware changes.

If you suspect a faulty stepper motor is behind your 3D printer problems, first check the motor’s wiring to make sure nothing is out of place. You might have to replace your printer’s motor if there are wiring problems. If you notice your stepper motor is overheating, adding a heat sink can help to mitigate the build up of heat and prolong the life of the motor. You can buy adhesive heat sinks to stick directly onto the extrusion mechanism. It’s worth bearing in mind that a heat sink will add weight to the extruder. In direct drive systems, this means your 3D printer’s motor will require more force to move the printhead across the build platform.

Key Takeaways

Clicking noises from your 3D printer should be reason for concern. The noises indicate that something is amiss or not properly calibrated. Luckily most causes of extruder clicking have a straightforward solution. Here’s what we covered in this troubleshooting piece:

• One of the most common causes of extruder clicking is related to temperature settings. If the print temperature is too low, unmelted filament will start to clog the nozzle and prevent consistent filament feeding. Increase the print temperature gradually to see if it helps.

• Leveling the print bed and ensuring proper calibration can minimize the risks of nozzle jams and help solve extruder skipping. 

• If there is too much friction in your printer’s bowden tube, the stepper motor will have to exert more force to feed filament into the printhead. Clean the bowden tube frequently or replace it if it becomes dented.

• Finding the optimal extruder spring tension and idler wheel tightness can promote a more consistent filament feed rate, which in turn reduces the risk of clicking, because the filament will keep up with the stepper motor.

• Stepper motor failure is a rarer occurrence but can create clicking noises. If this is the case, you may have to replace your extruder’s stepper motor, or the extruder overall.

References

[1] “What Is 50 Decibels Compared To Other dB”. Decibel Pro. [ Accessed February 2023] https://decibelpro.app/blog/what-is-50-decibels/ 

[2] “How to Set Extruder Tension”. CNC Kitchen. May 7, 2022. [Accessed February 2023] https://www.cnckitchen.com/blog/how-to-set-extruder-tension