What Causes Filament to Curl Out of the Nozzle? (Solved!)

As there are so many distinct components of the 3D printer working together to consistently push the filament out of the nozzle in the correct way, there are also many things that can go wrong during the filament’s journey between the spool and the tip of the nozzle as a result.

What makes matters worse is the severe unfavorable impact of a potential problem in the movement of the filament, as, depending on the scenario, it can lead to a wide variety of issues ranging from difficulties with layer adhesion to reduced visual quality.

In today’s article, our topic will be the problem of the filament curling out of the nozzle, in particular, which is an undesired way for the filament to come out of the nozzle due to the adverse effects it has on the quality of your 3D printed models, compared to the correct way of coming out straight.

So, what can cause the filament to curl out of the nozzle instead of coming out straight?

Below, you can find the most common reasons that can cause the filament to curl out of the nozzle:

  • Partial clogging of the nozzle
  • The usage of a too low first layer print temperature value
  • Printing with a bed that is not correctly leveled
  • The use of a Z offset value that is too high
  • Printing with a bed that is not clean

In the following sections, we will be analyzing each of the factors that can cause the filament to curl out of the nozzle in more detail, find out how to fix the issue of the filament curling out of the nozzle in an efficient way, and finally, go through the signs that may appear on your prints as a result of the filament curling out of the nozzle.

What Causes Filament to Curl Out of the Nozzle?

Since there are a few distinct factors that can prevent the filament from coming out correctly and cause it to curl instead, it’s not very possible for us to tell you what exactly is causing the problem in your case, meaning that you will need to conduct some detective work to get to the bottom of the issue.

Here are the factors that can cause the filament to curl out of the nozzle instead of moving out in a straight path, along with descriptions that clarify the reasoning:

  • The nozzle is partially clogged. When the nozzle is partially clogged, the filament will be met with some resistance as it tries to make its way out of the nozzle, which can result in it sticking to the source of the clog.
  • The first layer print temperature is too low. In cases where the first layer print temperature is too low, the filament won’t be able to reach a state where it’s sufficiently melted to flow out of the nozzle freely, which will result in it curling upwards as it’s pushed outside.
  • The print bed is not correctly leveled. A print bed that isn’t correctly leveled can cause the gap between the nozzle and the bed to be too large for particular areas of the print, which can cause the filament to curl back upwards due to it being unable to come into contact with the print bed.
  • The Z offset value is too high. Similar to a bed that isn’t level, the usage of a Z offset value that is too high will cause the nozzle gap to be more significant than optimal, potentially creating a scenario where the filament is unable to reach the print bed as it comes out of the nozzle.
  • The print bed is not clean. When the print bed is not clean, the strength of adhesion between it and the plastic will naturally weaken, which creates a situation where the filament becomes more likely to adhere to the nozzle rather than the print bed.

How to Fix the Issue of Filament Curling Out of the Nozzle?

As fixing the issue of the filament curling out of the nozzle is primarily about finding the culprit causing the problem in your case and applying the necessary fix, a trial and error process that involves going through the potential solutions will most likely be required.

Below are the solutions we recommend applying to fix the issue of filament curling out of the nozzle, with each solution corresponding to a potential culprit behind the problem:

  • Unclog the nozzle. Even though there are plenty of different ways to unclog a nozzle, our first recommendation would be to apply the cold pull process, which should efficiently resolve partial clogs that aren’t too severe. In cases where the cold pull method is not successful, cleaning the nozzle with a needle or complete disassembly and thorough cleaning with a solvent can be necessary.
  • Increase the first layer print temperature. Setting the first layer print temperature to a value roughly 10 degrees higher than the standard print temperature should be sufficient to ensure that the filament gets warm enough during the printing of the first layer.
  • Ensure that the print bed is correctly leveled. While bed leveling is an incredibly deep topic with plenty of different ways to go about it, carefully applying the paper method should do the job in almost every case.
  • Re-adjust the Z offset value to correct the nozzle gap. Similar to the process of bed leveling, you can also use the paper method to adjust the Z offset value and ensure that the nozzle gap isn’t too large. For best results, we highly recommend leveling the bed before adjusting the Z offset.
  • Clean the print bed. Even though the exact process of cleaning the print bed depends on the material you’re using, the aim is to ensure that the bed does not have any dust, dirt, or grease. As a result, touching the bed or placing any external items on it is something you will need to avoid once you’re done with the cleaning process.

What Are the Signs That Show Filament is Curling Out of the Nozzle?

As it may be difficult to notice whether the filament is curling out of the nozzle or coming out the intended way at first glance, the best strategy to find out whether you’re experiencing this issue is to look for the signs that may indicate that the problem is indeed occurring.

The best time to find out whether you’re facing the issue of filament curling out of the nozzle is during the printing of the first layer, where you can directly observe that the filament is refusing to stick to the print bed and curling upwards to stick to the nozzle instead.

When watching the printing of the first layer, paying attention to whether the filament makes some contact with the print bed and curls back up or does not even come into contact with the print bed at all and ends up sticking to the nozzle instead can be extremely helpful to find the root cause that’s creating the problem in your case.

Wrapping Up

While filament curling out of the nozzle can seem harmless at first glance, it’s actually a problem that can cause a significant loss of visual quality on your 3D printed models and, as a result, one that you should resolve as soon as possible.

To quickly recap, both maintenance-related issues, such as a clogged nozzle or a dirty print bed, and configuration-related issues, such as the usage of a low first layer print temperature, and a misadjusted nozzle gap stemming from a bed that isn’t correctly leveled or the use of a Z offset value that is not optimized, can create the issue of filament curling out of the nozzle.

As solving this issue practically comes down to ensuring that your 3D printer is maintained and configured well, with no actions requiring a high level of technical expertise, it should be a straightforward fix that won’t take much of your time and effort.

Happy printing!