5 Ways How to Fix Over-Extrusion in Your 3D Prints

Over-extrusion is quite a common problem that you find 3D printer users experience, and it results in print imperfections and poor printing quality. I’ve experienced over-extrusion myself and I find some great ways to fix it.

Most people fix over-extrusion by decreasing their nozzle temperature, since it makes the melted filament less viscous or runny. Lowering your extrusion multiplier or decreasing the flow rate in your slicer also works quite well. Double check that your slicer has the correct filament diameter input.

There are some fairly quick fixes to solve the problem of over extrusion, as well as some more detailed solutions, so stay tuned to learn how to fix over extrusion.

Why Do You Have Over-Extrusion in Your 3D Prints?

We can tell from the term over-extrusion, that the printer would be extruding too much material, which could be ruining the quality of your prints. There are multiple reasons for over-extrusion, such as the dimensional inaccuracy and high flow rates.

Let’s get into the detail of certain factors which are causing over extrusion in the printer and causing the problem in the printing process.

  1. Print Temperature Too High
  2. Flow Rate Set Too High
  3. Incorrect Filament Diameter
  4. Problem with the Nozzle Size
  5. Mechanical Issue with Z-Axis

If the flow rate of the printer is too high, along with a high temperature, your whole project could go south and end up as nothing but a messy, low quality 3D print, all because of over-extrusion.

Now comes the main point, how to fix these issues.

How to Fix Over-Extrusion in 3D Prints

1. Lower the Printing Temperature to an Adequate Amount

Sometimes the simple fix of lowering your printing temperature works a treat for fixing over-extrusion. You don’t always have to get into some complicated solution and tinkering to solve this problem.

The higher your printing temperature, the more your filament will melt into a runny substance, so it has the ability to flow more freely out of the nozzle.

Once the filament starts flowing freely, it’s harder to control, and your layers can start getting uneven because of this over extrusion.

  • Control the temperature by lowering it in your slicer settings or directly on your 3D printer.
  • Adjust temperature gradually because if it gets too much lower, you can face under extrusion, which is another problem.
  • You should go by decreasing the temperature with intervals of 5°C
  • Every filament has a different level of ideal temperature; make sure you are doing trial and error.

2. Manage The Flow Rate/Extrusion Multiplier

Flow rate, also known as flow compensation is a measurement of the amount of material extruded, which is then multiplied by the given flow rate value.

In Cura, these are set in percentages, where the default is 100%.

If mistakenly you have set the flow rate too high, you will see that too much filament is flowing out in less time, which is causing issues in the layers, resulting in the over extrusion of the layers.

It can damage the dimensional preciseness of the prints, and you will see your upper layers have larger dimensions than the bottom layers.

The optimal flow rate can easily change when using a different roll of filament, even from the same brand because not all rolls of filament are made the same.

  • Use trial and error to test different flow rates with a test model
  • I would use intervals of 2.5% for your flow rate testing
  • It’s a good idea to use small models so you don’t use too much time or filament

3. Adjust the Diameter of the Filament in the Slicer Software

This is another problem of misjudgment, which means that if your slicer is getting the wrong filament diameter, it will start extruding the material at a higher rate leading to the same over extrusion problem.

It will cause more material loss to you, and the surface of the layers will also be inconsistent.

This isn’t a common issue since filament tolerance has definitely improved over time, but it’s still possible. In Cura, you can actually manually change the filament diameter to reflect a lower or higher measured diameter in your filament.

  • You can use a caliper to measure the width of the filament from different places
  • Verify whether the diameter differences are within a good tolerance (within 0.05mm)
  • After getting all the measurements you can take out the average to get the right diameter of the filament
  • When you get the average number, you can put it into the slicer software

To get to this screen, you can use the shortcut Ctrl + K or Settings > Extruder 1 > Material > Manage Materials. You’ll have to create a ‘Custom Material’ to be able to change this setting.

Cura Filament Diameter Settings - 3D Printerly

In all honesty, you are probably better off using a new, high quality roll of filament rather than printing successful models.

4. Getting the Size of the Nozzle Right

Many people often ignore this part, but I want you to pay close attention to this, as your material will be coming out of it.

The nozzle plays the most important part in the designing of the material, and the wrong nozzle size could disrupt the results of your 3D prints by over-extrusion.

Basically, the nozzle size affects the printer extrusion width of the print that you are getting.

  • Well, when it comes to 3D printing, you can easily change your nozzle depending on the type of printing you are performing.
  • You can see before printing the model whether you require a bigger nozzle or a smaller one.
  • The right nozzle will avoid over extrusion as an adequate amount of material will flow out of it.
  • Now, if you are not getting the right results with nozzles like 0.4mm, you can go for smaller nozzles.
  • For some 3D printers, you can use larger nozzles to avoid over extrusion.

5. Loosen the Rollers on Your Gantry

This is a less well-known solution that can cause over-extrusion usually in the bottom layers of your 3D prints. When the roller assembly on your 3D printer is too tight, there is only movement when enough pressure has built up to get it rolling.

The video below starts at 4:40 and shows the tightening of the roller assembly on a CR-10.

If you tightened this roller on the right side of the gantry too tightly  you want to loosen up the eccentric nut so, there isn’t slack behind it, and it rolls with a bit of firm pressure.

Your bottom layers can bind on the Z if the gantry roller is too tight against the rail on the opposite side of the lead screw. It snags until the Z axis is high enough to relieve tension on the wheel.

Overall, follow this troubleshooting guide to fix the problem of over-extrusion, and you will be fine throughout your printing process, but as advice, always keep your printer, extruder, and nozzle clean for better printing results.

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