5 Best Ways to Fix a Clogged Extruder Nozzle & Prevention


Clogged Extruder Nozzle - 3D Printerly

3D printers really are great, but the problems that you can run into aren’t so much. One of these problems is the 3D printer extruder nozzle getting jammed or clogged up. It’s an issue that can be resolved easily so I’m going to share that with you guys in this neat post.

As you know, there are several different types of 3D printers meaning that there are going to be different ways for you to unclog a jammed nozzle. I’ve generalized some of these methods so that they can be used in most cases.

The best method to fix a clogged extruder nozzle is to use a probe such as a thin steel or brass wire that will fit up your nozzle to push any blockages through the nozzle. A combination of heat and force should dislodge foreign material from an extruder nozzle.

This method will work in a lot of cases, but you may need to combine it with more methods to get the results you want. Keep reading to find out how to do these methods efficiently.

1. Heating Up Extruder Nozzle An Extra 5-10°C

The simple, and most easy fix for unclogging a jammed extruder nozzle is to heat up your hotend to a higher temperature than you usually do for your desired material.

You want to heat it around 5-10°C higher to start with and after it’s at the desired temperature, try to push your filament through the extruder nozzle by hand from the top of the printer.

Filament can become quite soft meaning it may not unclog the jam which leads into the second way of unclogging a jammed extruder of using a hard, thin object to get rid of built up material and foreign objects such as dust.

This works best for jams which haven’t built up over time as so are weaker and not hardened to the inner extruder. Many times a clog will require a simple fix and you can go about printing as usual.

2. Probing Nozzle with Thin, Hard Material

As described above, using a hard, thin object to dislodge any clogs that prevent extruding is a great way to solve this issue. Foreign materials can really build up inside the nozzle so I advise to do this a few times to make sure you have everything removed. After the materials are unclogged, you should be able to extrude material adequately.

A material you want to use for should be something that is durable and strong. Some people recommend a guitar string or a piece of wire from a wired brush. As long as it fits through the nozzle and isn’t soft or too harsh, it should work fine without damaging the inner nozzle. It’s a fairly simple process of just trying to dislodge some hardened materials such as PLA or ABS, whatever you have been printing with.

A better recommendation here would be a manual micro-drill set. This one from Amazon will do the trick, it’s a multipurpose, 20 set drill with anti-slip properties and made of hardened steel.

When you think about the inside of an extruder nozzle, it’s got many nooks and crannies and may be difficult to unclog most of the jammed material with just a thin wire. You don’t want your extruded strands to be coming out at an angle because of uneven friction inside a dirty nozzle.

A micro-drill will work very well here and they are not only very useful, but very affordable.

It makes sense to get specialised tools for this so you are prepared for these issues in the future.

SIQUK has a sweet 3D Printer Nozzle Cleaning Kit with 30 pieces, along with 2 tweezers, a cleaning cloth and a neat little toolbox. This is more of a day to day maintenance kit so it’s a good purchase for any 3D printer user.

It’s a great little tool that you can use to clean your blocked 3D printer extruder nozzles. Simply heat your printer up, reverse the filament out, then run it to it’s full heat while putting the appropriate size needle into the nozzle. It should clean it out pretty easily.

This is best done as a routine rather than letting your nozzle get seriously blocked. With serious blockages it may require more than this kit, but if you use it regularly you can prevent these jams.

3. Cold Pull Method with Filament

The cold pull method is another way to unclog your extruder nozzle. The idea is simple, you pull a specific filament from the nozzle at a certain temperature which keeps the materials inside in one piece. It’s important to balance the temperature so it’s not too cool that it doesn’t allow the plastic to stretch enough to pull away from the nozzle, and not too warm that it’s in a molten state.

A guide on this has been written here, and explains the cold pull method in detail.

This cold pull technique is better done with a thermoplastic material that has a higher thermal transition property, meaning that PLA doesn’t work that great, but ABS much better. Nylon 618/645 works efficiently due to having the ideal flexibility, strength and low friction.


Cold Pull Temperatures

ABS – 160-180°C

PLA 80-100°C

Nylon 618/645 – 140°C


The cold pull technique has been successfully done with both ABS (this was the best material to use for a long time, with a cold-pull temperature of about 160-180°C) and PLA (much more difficult due to its thermal transition properties, but a cold-pull temperature of 80-100°C will sometimes work), but Nylon from Taulman (pull temperature of 140°C) is far easier and more reliable to use for this purpose due to its strength, flexibility, and low friction.

Steps for this method:

  1. Dislodge as much plastic as you can using a probe and a cold pull with ABS or PLA.
  2. Heat your nozzle to 240°C so it can melt the Nylon and push the filament in
  3. Extrude the Nylon slowly
  4. Once Nylon comes out the tip, begin cooling nozzle to pull temperature (140°C)

Depending on what happens with the Nylon that comes out from the extruder, you may have to repeat the dislodge process with the thin metal wire because some hardened material can be quite stubborn. When you have all the hardened material unclogged, you should be fine to push all the old material build up with the Nylon pull.

A good thing about this method is you will know if it’s successful due to indications on the Nylon material. If it comes out rough and discolored, it means there is still residue inside the nozzle.
If this happens you’ll just want to clip off the end of the material and repeat the process until the Nylon comes out mostly white.
Here is a great video describing the process.

4. Remove and Clean the Blocked Extruder Nozzle (ABS)

One method a person has used to clean a blocked extruder nozzle is using acetone, a torch and thin wire.

Steps for this method:

  1. Remove your nozzle from the 3D printer and soak it in acetone for roughly 15 minutes to clean out dirt.
  2. Use a soft cloth to clean the nozzle after soaking
  3. Use a stone or a brick and put the nozzle on top, then use a torch to heat up the nozzle for around a minute. It should be very hot
  4. Pick the nozzle up with tweezers and use thin wire to clear the hole in the nozzle. Copper wire worked well for this method.

You should be able to disassemble your extruder nozzle but you want to make sure it doesn’t void any warranty that you may have. Depending on what printer you have, there should be guides out there to help you get to this stage.

After heating up the nozzle and removing the leftover material inside, you just simply reinstall your nozzle and retest it by printing as usual.

It is a somewhat long process, but it’s the difference between getting your prints coming out successfully or going through more failed prints.

Many times, since manufacturers aim to save on costs of producing 3D printers, they may get cheaper, low quality parts which don’t do the best job. This is why people will replace their extruders with higher quality ones straight away, to avoid many of these common problems.

The nozzle that I recommend is the SIQUK 22 Piece Nozzle Set from Amazon, made of high quality brass material and has great user ratings.

5. Preventing your Nozzle From Getting Clogged

This is a bit of a sneaky one as it isn’t necessarily a way to unclog a jammed extruder, but it definitely is a method to stop it happening in the future!

Prevention is the best method to avoid having to repeat this process over and over again. Once we know what causes these jams, we can work towards making sure it doesn’t happen nearly as often.

There are a many things which are known to create these jams:

  • Nozzle height when extruding
  • Temperature not being at the right level
  • Tension issues such as when spool is running out
  • Incorrect calibration with bed levels
  • Moisture in filament

Nozzle Height

Having your nozzle at the correct height is very important in how the printing process will end up.

When your nozzle is too close to the print surface, your filament will regress away from surface which will cause upward pressure, jamming the nozzle.

On the other hand, when your nozzle is too far, the material will be extruded far from the surface meaning the filament won’t have good adhesion to the surface layer.

Temperature

As mentioned throughout this post, temperature settings are a big factor in preventing your nozzle from getting clogged.

Different filaments require different temperatures, even the same filaments but of different types/brands such as PLA vs PLA+ can have differences in the optimal temperature for printing.

This mainly comes down to trying out the recommended temperature, then depending on your results, adjusting the temperature in a trial and error fashion until you get the successful prints you desire.

When your nozzles aren’t at the best temperature for a material, it tends to cause clogs. This is because filament won’t be at a soft enough level to extrude through the nozzle or it’s at a level where the rate at which the material extrudes is not quick enough to release it through without cooling down too quickly.

Having your extruder at a temperature too high is unlikely to result in clogging but it can result in filament extruding at low quality.

One user actually had jamming issues with PLA and they raised the temperature to extrude PLA at 220°C. The filament loaded alright, but would jam in the hot end after a few layers. This happened because the material would get partly melted higher than where it was supposed to, then when extruded, it cooled down too quickly to the point where it hardens the filament in the tube.

When the material feeds faster through the extruder nozzle, it causes a jam. In this case, the user lowered their extruder temperature to 180°C and it solved the issue. Even though it’s against what people would usually advise it did help because of the initial cause of the problem. So it can take some trial and error to get correct but you’ll get there with time.

Tension Issues

A good solution which you can actually print yourself is the infamous TUSH (The Ultimate Spool Holder). It is a known fix to reduce tension from your filament and has over 100k downloads from 3D printer users. The TUSH is a bearings-based spool holder which reduces jerking motions and extrusion inconsistencies. Many users note that the improvement resulted in much fewer failed prints, as first layer adhesion increased.

If you want one that’s been professionally manufactured for the job, this Spool Holder from Creker is a great choice. It provides the perfect tension for your filament to feed properly to your 3D printer. This spool holder is very durable and has an almost friction-less surface which allows for filament to unspool freely.

It’s a good option because it has a universal use since some spools of filament vary in size and shape.

Certain changes can occur with a 3D printer over time which results in tension issues arising with your spool filament. Getting to the end of a spool of filament makes the tension feed tighter and increases the pressure of it feeding to your printer. Once this happens your printer will have to work harder to fight against this tension while extruding the same amount of plastic.

This is likely to give you negative results with prints.

You want to make sure that the materials that you are loading into your printer is done correctly, and with very little tension. When it is mounted and can spin without hindrance, you’ll know that tension issues won’t be affecting your prints, and will reduce the instance of your extruder nozzle getting clogged up.

3D printers vary in their design so there will be different ways to load up your filaments. Having a spool holder is a great addition to combat any variation in filament tension.

Incorrect Calibration

To get the best results from your 3D printer it is essential that you have the correct calibration. Calibration is what makes sure that all your prints come out in a similar fashion each and every time.

3D printers have different calibration methods, some being manual and others being controlled automatically with software. Over time, print beds made of some materials such as metal can start to warp and bend, which effects the accuracy of where material is extruded.

The automatic calibration methods are the most effective because they operate while you print, and can still print accurately, even with uneven bed surfaces.

Below is a video showing how effective automatic calibration methods are.

Regular calibration can identify and solve this issue, and is especially useful when preventing jams.

MatterHackers put together a useful guide on setting up automatic print levelling, which works with most 3D printers out there. It is just six easy steps so I recommend getting this set up as soon as you can.

Making sure your calibration is perfect is something you don’t want to be worrying about every time your starting a new print. When it’s done correctly, it should prevent your prints getting clogged for this specific reason which should reduce your overall occurrence of jammed extruder nozzles.

Moisture in Filament

Humidity or moisture can affect filaments of all types, and have an impact not only on print quality, but the presence of clogging in the nozzle. 

Moisture can cause many issues in filament such as:

  • Increased fragility
  • Expansion of material
  • Filament degradation
  • Brittle and easily broken
  • Requiring higher temperatures for extrusion

If you have materials left in your printer while it’s idle, this can result in the material getting stuck because they will absorb water and expand, clogging the extruder up. When this material is heated up again, it produces gaps within the filament which turns into a thick substance which clogs the nozzle. 

Some materials have a higher instance of this happening due to their increased ability to absorb water such as nylon.

Materials which have high-resistance to water absorption are PETG, CPE and HG100 which can be exposed to water for long periods of time without issues.

3D printer users have mentioned solutions to this being airtight storage of filaments, with some kind of desiccant to absorb moisture in the air. Others have even put their filament in the oven on a low heat for some time to heat the moisture out of the material.

Heat Creep Issues

One issue that people sometimes run into when their nozzles quickly get clogged up is from heat creep. This is a phenomenon where heat creeps up the hotend, where it’s not supposed to, then softens up the filament in the chamber which easily jams up the filament path.

It can be caused by incorrect settings or a poor hardware setup which causes your filament to swell up.

The best solution here is to reduce the heat from transferring to this location. Even though high temperatures are going to add to this issue, there is more of an underlying cause that needs to be fixed. It can also be from print speeds and rertaction distance.

I would advise tuning up these settings:

  • Lower your 3D printing temperature
  • Reduce your retraction distance
  • Increase your print speed

You are more likely to experience heat creep if you have an all-metal hotend because the heat break shielding doesn’t do a great job reducing the heat transfer.

Make sure your grub screws are on tight, because they can loosen up over time with all the 3D printing vibrations.

Depending on your setup, you might have to buy a new hotend to fix this issue. If you have a fairly good extruder and changing the settings work, then you should be fine, but if not, it’s probably time for a change.

A high quality hotend that should solve this issue is the Sovol Creality Hotend. This awesome deal comes with Capricorn PTFE Tubing, x3 Silicone Covers & x3 0.4mm Nozzles. It is an MK8 Hotend Kit which aims to give you authentic 3D printing quality

Soemtimes upgrading your fan can do the trick, so I would recommend getting the Noctua NF-A4x10 FLX Fan. This is a well-respected, quiet yet high-performance fan that works well with 3D printers.

 

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