What Causes Ender 3 (Pro/V2) Over-Extrusion? (How to Fix?)

There is no doubt that over-extrusion is one of the most commonly encountered issues in 3D printing, causing many annoying symptoms such as stringing and blobbing, oozing, nozzle jam, bad surface quality, and many more, ruining the printing process.

Despite being the most popular 3D printer on the market right now, Creality’s Ender 3 isn’t clear of the over-extrusion issues either, as no matter the quality, any wrongly configured 3D printer can easily suffer from over-extrusion problems.

Today, we will explore the factors that can cause the Ender 3 to over-extrude and find out ways to solve the over-extrusion problem as quickly and efficiently as possible.

So, what causes the Ender 3 to over-extrude?

Here is a list of the things that can cause the Ender 3 to over-extrude:

  • Too high print temperature
  • Misconfiguration of filament diameter
  • Misconfiguration of nozzle size
  • Miscalibration of extruder (steps per mm)
  • Too high flow rate (extrusion multiplier)

In the upcoming sections, we will analyze the factors that can cause the Ender 3 to over-extrude in more detail, discuss the potential solutions you can apply to fix the over-extrusion issue, and look at some of the signs that indicate your Ender 3 may be over-extruding.

What Causes Ender 3 (Pro/V2) Over-Extrusion?

As the factors that can cause the Ender 3 to over-extrude are plentiful, we believe that analyzing them individually in detail, including the other symptoms they create, will be most helpful to identify the one that is actually causing the problem.

Print Temperature Too High

Print temperature is one of the easiest things to get wrong, making it the most likely cause behind your Ender 3 over-extruding plastic.

When the print temperature is too high, the filament melts more than it should in an optimal scenario, which prevents the nozzle of your Ender 3 from controlling the flow.

In such a case, you will also observe signs such as:

Misconfigured Filament Diameter

While rare, misconfiguration of the filament diameter value is a surefire way to cause your Ender 3 to over-extrude.

When the filament diameter value you put into your slicer settings is lower than the actual diameter of the filament you use, your Ender 3 will extrude more filament than it should, causing over-extrusion.

In the case of a misconfigured filament diameter, you will observe signs such as:

  • Poor surface quality
  • Extruder clogging
  • Dimensional inaccuracies

Misconfigured Nozzle Size

Even though the misconfiguration of the nozzle size value is rare, as it’s not a value that frequently sees change, it can easily cause your Ender 3 to over-extrude.

When the nozzle size setting in the slicer is higher than the actual size of your printer’s nozzle, your Ender 3 will extrude more filament than it should and cause over-extrusion.

With a misconfigured nozzle size value, you will also observe signs such as:

  • Poor surface quality
  • Extruder clogging
  • Dimensional inaccuracies

Miscalibrated Extruder (Steps per mm)

Even though extruder calibration isn’t a topic that comes up often, over-extrusion can also happen due to the miscalibration of your Ender 3’s extruder.

When the steps per millimeter value of the extruder is higher than it should be, your Ender 3 will end up extruding more plastic due to the steppers pushing out filament through the nozzle.

With a miscalibrated extruder, you can notice signs such as:

  • Dimensional inaccuracies
  • Poor surface quality

Flow Rate (Extrusion Multiplier) Too High

As the flow rate is the parameter that directly controls the amount of plastic that comes out of the extruder, there is no denying that it can cause under or over-extrusion quite easily.

When the flow rate (extrusion multiplier) setting is too high, your Ender 3 will end up over-extruding due to the slicer instructing the printer to extrude more plastic than optimal.

With a flow rate value that is too high, you will also observe signs such as:

  • Extruder clogging
  • Inconsistent (too large) layers

How to Fix Ender 3 (Pro/V2) Over-Extrusion?

While fixing the Ender 3 over-extrusion problem should be simple once you pinpoint the root cause, it’s not always easy to do so.

If you haven’t been able to find out what may be causing the over-extrusion problem in your case, here is a step-by-step guide that you can follow, which will provide fixes for all the possible factors that can contribute to over-extrusion.

  1. Decrease the print temperature. We highly recommend setting the print temperature to the value the filament manufacturer recommends. If that is not available, going with the lower end of the optimal print temperature value range for the filament type you use should also do the job.
  2. Re-configure the filament diameter value. Ensure that you’re using the correct filament diameter value in the settings of your slicer by measuring your filament with calipers and double-checking the value.
  3. Re-configure the nozzle size value. Ensure that the nozzle size value you use in your slicer’s settings is equal to the size of your nozzle, specifically if you frequently change nozzles.
  4. Calibrate the extruder. While it’s a factor that we often overlook, there is no denying that the steps per millimeter value plays a vital role in the rate of extrusion.
  5. Decrease the extrusion multiplier (flow rate). While the flow rate is the least likely culprit, incrementally reducing the value by small amounts can prove to be helpful at times.

Aside from correctly configuring the settings that may be wrong, here are some slicer features you can activate to combat the issue of your Ender 3 over-extruding in some cases:

  1. Enable retraction. Enabling retraction reduces the chance of over-extrusion significantly by pulling the filament back during travel moves, which should especially come in handy if you’re facing symptoms of stringing and blobbing.
  2. Enable the coasting feature. Coasting is a feature that turns the extruder feed off slightly before the printer completes a line, causing the printer to use the oozing plastic to finish it instead. If you’re facing over-extrusion issues near the end of a print line, coasting can come in handy.

We highly recommend following the guide in order and running test prints after each step to see whether the problem is still going on or not.

What Are the Signs of Ender 3 (Pro/V2) Over-Extrusion?

As over-extrusion can present itself in the form of many symptoms, a vital part of fixing the issue is making sure that the problem actually is over-extrusion; and not something else.

Below are the signs you should be observing if your Ender 3 is indeed over-extruding:

  • Oozing and blobbing
  • Stringing
  • Dimensional inaccuracies on the model in both width and height
  • Drooping layers, especially on the upper parts of the model
  • Nozzle jam
  • Overall loss of surface quality

While facing only one or two of these issues could also mean that a different issue is troubling your prints, observing the majority of them points to over-extrusion being the problem in most scenarios.

Ender 3 (Pro/V2) Over-Extrusion on First Layers – What to Do?

As the process of printing the first layer of a model is quite different than printing the rest, experiencing over-extrusion on the first layer, but not the rest, is highly likely.

If your Ender 3 is over-extruding on the first layer but not the rest of the print, we recommend incrementally lowering the first layer print temperature and the first layer flow rate (extrusion multiplier) while running a series of test prints.

As issues with the filament diameter, extrusion calibration, or nozzle size would cause signs of over-extrusion to show up all over the model, parameters that may require specific configuration for the first layer, such as print temperature and flow rate, are the most likely culprits.

Wrapping Up

Due to the many different factors that can cause the problem, over-extrusion can be a real headache to deal with, no matter which printer or filament type you use.

To quickly recap, let’s take a look at the things that can cause your Ender 3 to over-extrude one more time:

  • Using a print temperature that is too high
  • Misconfiguring the filament diameter
  • Misconfiguring the nozzle size
  • Miscalibrating the extruder steps per millimeter
  • Using a flow rate that is too high

More often than not, going over the elements above and ensuring that everything is correctly configured should fix your problem and bring the extrusion rate of your Ender 3 to optimal levels.

Happy printing!