There’s no such thing as a ‘pristine’ environment when it comes to 3D printing. Inevitably, some form of clog will eventually form in the nozzle of your machine. Filament-based printing isn’t without its advantages, but slowdowns like this are one thing you’ll have to navigate. On this page, we’ll explore how to unclog the printer nozzle on your 3D printer.
We’ll cover the main causes of the most common blockages and how best to overcome them.
How to Unclog a 3D Printer Nozzle – Video Guide
If you learn best by video or are pressed for time, this 7-minute video guide from Thomas Sanladerer is well worth a look.
It covers the basics of cleaning out your printer’s nozzle and some of the most common things you’ll have to look out for.
What Causes Blockages in Your 3D Printer Nozzle?
Before you can fix your machine, you’ll need to understand what’s actually blocked it. It’s said that an touch of prevention is worth days of cure… and this is no different.
So, although you’re probably here because you’re looking for the solution to a blocked nozzle right now – come back here (or read it now) to make sure you don’ have to go through this again next time.
Lack of Proper Maintenance
Perhaps the most common – and easily avoided – cause of 3D printer clogs is a lack of proper maintenance.
Every time you switch filaments, reposition elements, or open up your machine you should make a point of cleaning out any old filament or debris that’s been left behind.
This can be as simple as gently brushing down with a wire brush.
Sure, it takes a little time but failing to maintain your printer will eventually lead to blockages, headaches, and (if you’re me) a lot of cursing.
Dust Plugs
In general, it’s best to use your printer in an environment that’s as close to ‘dust-free’ as possible. This is rarely practical, though.
When dust forms on the surface of an old or dirty filament you can get what’s known as a ‘dust plug’ forming.
And yes, it’s exactly what it sounds like. A “plug” of dust that will quickly jam up your printer’s nozzle, grind your projects to a standstill, and – you guessed it – lead to a lot of cursing.
Filament Stripping
Depending on your specific setup, the nature of your extruder gear, and which filament you’re using, bits of your filament may be getting stripped – or gouged – by your equipment.
Without enough material for the extruder gear to “bite” into the gear is left like car tires in mud… spinning but not doing anything useful.
It’s easy enough to fix (see below) but if you’re having this happen often it might mean the temperature is off and is either weakening the filament too early or not melting it fast enough and it’s jamming.
Clogged 3D Printer Nozzle Home Diagnostics – The Basics
So, how do you go about figuring out if your machine is blocked and why?
You learn how to diagnose it like a scientist. Or a car mechanic.
Either way, once you know how to run diagnostics at home, cleaning and fixing your printer becomes much easier.
The first step is to manually push the filament through and pay attention to how it behaves.
Follow these basic steps:
- Disengage your extruder gear
- Choose a filament and manually push it through
- Pay attention to how it behaves
Notice lots of resistance? Is the filament curling? Not coming through at all?
If you said yes, your nozzle is probably clogged.
Remember that it shouldn’t take much force at all to push the filament through so there’s no need to force things here.
Missing Layers
If when printing your designs, you notice that several layers appear to be missing, this could be caused by a clogged printer nozzle.
Be sure to double-check that you’re using the right filament diameter. Also, use calipers to be sure the listed diameter (usually 1.75mm) is the actual diameter or it could be throwing off your e-steps – possibly causing incomplete prints.
Missing First Layer
If you notice that the first layer of your designs fail to print, this could also be a sign that your printer’s nozzle is clogged. Other potential causes of missing first layers could be your extruder or level bed so be sure to give these a once over too.
Intermittent Extrusion
One of the most obvious signs that something is blocked is how consistently your filament is leaving your nozzle. If it seems to slow down and then suddenly ‘burst’ out again, you almost certainly have a nozzle clog.
The good news is that the process for clearing things up again is relatively straightforward.
Unclogging a 3D Printer Nozzle – What You May Need
We run through five different options for unclogging your nozzle below. You won’t need all of the items listed below, but you might need a combination of a few of them:
- A brass wire brush (avoid harder metals as this can scratch your machine)
- A clean, lint-free cloth
- Alcohol wipes
- A thin, long needle (an acupuncture needle or guitar string can work great, avoid drill bits because they break too easily and are hard enough that they can easily damage your nozzle)
- A blowtorch
- A wrench kit that’s compatible with your machine (usually socket and crescent wrench, at a bare minimum)
- Cleaning filament
- Acetone
Your Options
We explore how to unclog 3D printer nozzles below. Keep in mind that it’s best to start small and then build your way up to the more intrusive methods when you actually need them. The more hands-on a method is, the higher the likelihood is that you’ll damage your printer!
Option One – ‘The Wipe’
While your nozzle is still hot, wipe it down thoroughly with either an alcohol wipe or damp cloth. In some cases, the resulting steam will be enough to dislodge anything that was causing a blockage in your 3D printer’s nozzle.
The high alcohol content of certain wipes can also help clear up any lingering grime and unwanted debris.
Try ‘the wipe’ method first. It’s easy, fast, and it can often be all you need to get things running smoothly again.
If you had no luck with this option, move on to the next options.
Option Two – ‘The Stab’
You’ll be using a long, thin needle for this method. Heat your printer to the right temperature for the last filament you used. Gently insert the needle and pull it back and forth a few times.
Don’t use a drill bit! Some guides online will suggest that but it can easily damage your printer.
The goal here isn’t to dislodge the blockage; you’re just trying to break things up so that they clear on their own.
Be aware that this method isn’t appropriate for 3D printers with more delicate, thinner nozzles, proceed with caution, and skip this method if you’re unsure.
Option Three – Cleaning Filament
There are a number of cleaning filaments on the market that are designed to clear clogs from your printer’s nozzle. When used regularly, they can even help prevent new blockages from forming.
Be sure to choose a cleaning filament that’s the right diameter for your printer’s nozzle. Follow the specific guidance from your manufacturer on how to use your new filament.
In most cases, it’s possible to ‘print’ a small amount of cleaning filament through your nozzle at a printing temperature, cool your printer down so that the filament solidifies, and finally pull the solid lump of material out to unclog your machine.
Option Four – Disassembly
It’s sometimes necessary to just completely remove your nozzle and take out the blockages manually. The specific process involved here will depend on your make and model of printer.
In general, however, you’ll be using wrenches to take your machine apart.
Follow these basic steps when working:
- Set your printer’s temperature to the right level for the last filament you used. You’ll need to heat the filament so it’s soft enough to release the nozzle.
- Hold onto your heater block using a wrench while you remove your nozzle using another wrench
- Take all the necessary precautions to avoid burning yourself!
- The clogged filament can now be removed manually with the right chemicals or with enough heat
ABS filament dissolves very readily in acetone. Other filaments can be carefully heated with a blowtorch to help loosen and remove them. Don’t apply heat directly to your nozzle as you might melt that too!
Option Five – ‘The Brush’
It’s important to use a brass brush here and avoid harder metals that could damage your printer.
Gently brush away old filament from your nozzle using circular motions. Much like ‘the wipe’ method described above, this can often be all that’s needed to get things up and running again.
The ‘Last Resort’
In the vast majority of cases, this option won’t be necessary at all. In extreme cases where your nozzle has been blocked beyond repair, the best course of action is sometimes to simply replace or upgrade your existing hardware.
A newer, more premium nozzle may even come with anti-clogging features that make it far less likely that you’ll have to deal with unwanted debris in your machine. Starting fresh with a new nozzle can be an opportunity to start maintaining your machine properly.
By using cleaning filament from time to time, regularly clearing debris from your nozzle, and keeping an eye on the overall performance of your machine, you’ll stand a much better chance of keeping everything as it should be.
Final Thoughts
We hope you’ve found our suggestions on this page helpful. Remember to start with less intrusive methods first and build up from there. We recommend starting with ‘the wipe’ and ‘the brush’ approaches outlined above.
Only progress to using needles and blowtorches if it’s necessary to clear blockages from your printer.
Whichever approach you choose, we hope it helps to keep things running smoothly for many years to come. Happy printing!
