Key Takeaways

  • Untangle mid-print: Move the spool closer to the feeder, pull the slack back, and feed the spool through the knot. Or use the ‘change filament’ option to pause the print.
  • Re-spool the filament: Unroll the filament from the spool and carefully reroll it so it’s tight and non-overlapping. Use a filament respooler or an electric drill to speed up the process.
  • Prevent tangling: Keep the filament tight and secure on the spool, place it close to the extruder, and store it vertically. Use a filament guide or clip to avoid slack and jumping.
  • Fix printing issues: Check for clogged nozzle, warped prints, poor layer adhesion, and filament damage caused by tangled filament. Adjust layer height, print temperature, flow rate, and nozzle size accordingly.

Tangled filament is one of the most frustrating problems any 3D printing enthusiast can encounter. It wastes material, leads to poor quality or failed prints, and can even be dangerous if left unchecked.


In this guide, I’ll explain what causes 3D printer filament to tangle, all the common causes and solutions, and filament storage advice to avoid knots in the first place.

After my step-by-step untangle instructions, we’ll also weigh up how a filament guide can help you save time and money – and teach you how to print your own at home!

What Causes Knotted Filament?

It’s practically impossible for filament spools to come out of the factory knotted due to how they’re initially spooled.

So long as it’s kept straight during the spooling process, which all reputable manufacturers are careful to do, a fresh spool will never tangle while being packaged.

Filament knotting is actually caused by owners allowing their filament to become loose by accidentally failing to keep the filament suitably tense on the spool. And it’s a very common problem even amongst 3D printing veterans.

If this is allowed to happen, some rings of the loose filament will begin to widen and shift sideways over to a tightly coiled part of the filament, becoming tangles. This is similar to how improperly stored Christmas lights or earphone cables will tangle if left too loose, and those of you who know that pain will know how important it is to untangle filament.

Once a filament spool has tangled, it can take a while for the knot to become tight and “lock up”, so you may not notice the problem until well into your print.

How to Untangle Filament Spool Mid-Print

If you notice a tangled filament spool mid-print, you’ll need to learn to deal with it immediately to avoid wasting your filament and ending up with a failed print.

The first thing to do is unmount the spool and move it closer to the feeder entrance, giving you some slack to play with. Be sure to do this carefully, making sure you aren’t at risk of touching any moving or hot parts of your printer.

You can then pull the slack back through the knot to create a big enough loop to feed the spool through. It’s the same principle as if you’d stopped the print and removed the filament altogether, except you’re treating the spool as the filament end.

Once untangled, simply place it back on the spool holder and ensure that it’s not moving too freely to cause it to happen again. Keep an eye on the filament feeding for a little while to make sure the problem has been solved.

If your printer is equipped with a tuning menu, you may be able to access a ‘change filament’ option designed to print one project with multiple filaments. This will halt the print safely and give you the chance to untangle the filament without worrying about timing.

Alternatively, you can also reduce the print speed to slow down extrusion and buy yourself more time, making untangling the filament both easier and safer to manage.

How to Reroll Your Filament Tangle-Free

One of the easiest fixes for tangled filament is simply unrolling the filament from the spool and carefully rerolling it so it’s tight and non-overlapping. It may take a lot of time, and even be tedious, but it’s a simple and effective way to make sure your filament isn’t tangled or indeed going to tangle anytime soon.

We have included a visual demonstration along with step-by-step instructions below.

To re-spool your knotted filament like the above video, simply follow these easy steps:

  • Unload the filament from the printer (if necessary)
  • Unravel the filament (the entire spool if needed) until you’ve found the tangle
  • Rewind the spool carefully, making sure it’s tight and straight without overlapping itself
  • Secure the filament to the spool with a strong clip, or reload it onto your 3D printer

In essence, rerolling your filament to remove tangles is as simple as manually winding a vacuum cleaner cord. Simply straighten the filament out and rewind it carefully back.

However, this will be very time-consuming if you have larger filament spools. If this is the case, you may benefit from a filament respooler to save you both time and effort. Alternatively, you can also use an electric drill on a low setting to rotate the spool holder for you.

Consequences of Tangles in Filament Spools

Filament tangles in 3D printing can cause costly failures and hardware damage, impacting time, resources, and productivity. In professional or academic settings, this can cause missed deadlines and hurt your margins.


Particularly small tangles may not lead directly to failed prints, but they can cause the printer to over-exert itself while extruding. This will lead to small, maybe even imperceptible, vibrations while printing, which will warp prints and even completely ruin them.

Warped 3D Print Knotted Filament

The most common issues with 3D printer vibrations are ghosting and ringing. And while there are a few ways to fix these, ensuring your filament is free from knots and tangles is a good way to avoid the issue altogether.

If left unchecked, these vibrations will cause moving parts to overexert and even clash together, causing potentially irreparable (and expensive) damage to your hardware.

Clogged Nozzle

Knotted filament won’t go through the extruder in the smooth line it was designed to. This leads to melted filament bunching up in the extruder and eventually clogging the nozzle.

Clogged Nozzle

Clogged nozzles lead to a host of further issues like warped prints, poor layer adhesion, and even damage to the extruder itself. If you run into such problems or hear a clicking sound during the printing process, then your nozzle is likely clogged, and that could be because of entangled filament.

Damaged Filament

Another issue caused by tangled filament not properly extruding is the filament itself becoming damaged. If it’s not fed through the extruder smoothly, it will scrape against both the feeding system and the extruder will be unable to pull it efficiently.

Damaged Filament

This effectively leads to the filament being ‘eaten’ by the pulley, damaging it on the way through and out, severely impacting the print. This not only wastes filament, but also costs valuable time and will lead to you needing to start the print from scratch.

Common Causes of Filament Tangles

Filament Spool Not Spinning

Like any spooled material, 3D printer filament needs to be able to spin easily for smooth feeding and extruding. If the filament doesn’t roll off the spool as easily as it should, then it will begin to overlap, bunch, and eventually tangle.

The most common cause of this is incorrect or inefficient filament placement, causing it to loosen. If the filament is set in an awkward position or too far from the printer, the increase in tension needed for feeding can cause the filament to bend, which will heighten the risk of tangling.

3D Print Filament Feeder

A simple fix for this is to place the filament as close to the extruder as possible.

You can also use a filament guide, which is an extra holder for your filament to make sure it feeds into your 3D printer smoothly and efficiently. They’re a great way to add an extra safety measure against tangling, and they help avoid other issues like clogging too.

The best part is, you don’t even have to buy a filament guide because you can always print one yourself!

Loose Spool

Filament can also become loose purely because of the spool holder itself.

Filament spool holders bought from reputable manufacturers will almost always be perfectly fine. But if you’ve reused a spool holder or have found yourself using one with low rolling resistance, then it could end up spinning too fast for your printer’s speed setting to keep up with, leading to increased slack.

It’s worth noting that this is also a risk with spool holders that use bearings, this is because it lowers the friction and can lead to the spool spinning too quickly, making the filament ‘jump’ off the holder.

Loose Filament Spool

Fortunately, you can easily fix this simply by restraining the filament and ensuring an ideal amount of tension to reduce slack, similar to how people would manually feed thread through a spinning wheel so it stayed tight.

Be careful if you’re doing this mid-print, however, as tugging too much on the filament will strain and potentially damage your printer’s feeding system.

The goal here is to essentially increase tightness and friction, but only in slight increments.

How to Prevent Filament Tangles

The best way to fix the issue is to stop it from happening in the first place.

Before Printing

While tangled filament straight from the production line is rare, it’s still good to look out for. Depending on the filament, it will either be fastened through a hole in the spool itself or secured with tape.

When you begin to unravel your new filament, be sure to keep a tight hold on the end to maintain the tension and keep it tight enough. This will help avoid giving too much slack, which is the main cause of tangles and knots.

After Printing

Once you’ve finished with your filament for that print, make sure you store it correctly. Pull the filament tight around the spool so there’s no slack before refixing it, using either the guide hole in the spool or a filament clip. This will stop the spool from unraveling when not in use and tangle over time.

If you must store on its side, at least make sure the filament is tightly secured. 

Storing your filament vertically is a good idea as an extra precaution. This will prevent the spool from tangling if there is still any slack in the roll.

Printable Accessories to Prevent Filament Tangles

As well as purely manual fixes, there is a wide array of tools you can print at home to prevent your filament from becoming knotted or tangled.

Dragon Clip

The Dragon Clip, named for its shape, is one of the easiest solutions to filament tangling, both to print and to use. Using only 1.75mm of filament, it’s the perfect solution to your feeding and tangling issues, helping you get just enough slack regardless of the kind of filament you’re using.

Dragon Clip for 3D Printer Filament Universal

It achieves this by having a wide ‘neck’ that’s designed to hold filament of just about any thickness or fragility, making it an ideal universal filament clip and a great fix to tangling due to excess slack off the spool.

Anti-Tangle Filament Spool Holder

  • Download: Thingiverse
  • Designer: Ryan_Ghosh
  • Price: Free

The anti-tangle filament spool holder is designed to prevent the filament ‘jumping’, reducing the risk of too much slack forming as the filament is fed to the printer. This helps significantly reduce the risk of tangles and looks pretty stylish while doing it.

Filament Winder 3D Print

This holder can manage up to 90mm spools, meaning you should be fine with almost any standard filament you’re using. The link above includes instructions, tips, and extra equipment you’ll need, so it’s perfect for any beginners out there who are struggling with tangled filament and need an easy (but creative) way to prevent them.

Filament Clamp

  • Download: Printables
  • Designer: camolito
  • Price: Free
  • Compatible with: 1.75mm filaments

This designer was just as sick of their filaments tangling while in storage as the rest of us, and made this very simple filament clip for any 1.75mm material.

Universal Clip for 3D Printer Filament

The simple design holds the filament in place while not in use, preventing any slack or overlapping happening over time and ensuring the spools remain tangle-free.

This quick and easy solution can even be modified to hold different-sized filaments.

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