In 3D printing, over-extrusion is a common issue. However, if not addressed on time, 3D printer over-extrusion will not only increase printing costs and material waste, but result in incorrect dimensions and appearance, and compromise the quality of the prints.

In this case, it is important to know what causes 3D printing over-extrusion and how to fix it. In this article, we'll delve into the root causes and provide workable solutions to help you achieve better results in 3D printing.

What Is 3D Printing over-extrusion?

over-extrusion in 3D printing refers to an excessive amount of filament emitted from the 3D printer nozzle onto the build bed. This issue typically has something to do with improper settings of parameters in 3D printers, such as printing temperature and speed.

Despite its common occurrence, over-extrusion often comes with problems like oozing, blobs, stringing, and jams, impacting the size and quality of the printed object. It is worth noting that almost all 3D printers encounter this issue, which is not tied to specific hardware or filament.

What Causes 3D Printing Over-Extrusion?

As mentioned earlier, the 3D printing setup is the primary cause when it comes to over-extrusion of 3D printers. In specific terms, however, three potential printing parameters can directly lead to this issue.

Excessive Printing Temperature

If the temperature setting of the 3D printer is too high for the filament you are using, it can cause the filament to melt too quickly. In this case, the nozzle can lose control over the flow rate, leading to filament oozing from the nozzle. 

Improper Filament Diameter

If the filament diameter is smaller than that of the print nozzle, the filament will be extruded too quickly from the nozzle, causing 3D printing over-extrusion. Similarly, if the filament diameter is set up in the slicer incorrectly, it can also result in an improper flow rate and over-extrusion.

Incorrect Flow Rate Calibration

Flow rate denotes the quantity of material extruded per second, determined by factors of print speed, nozzle size, and layer height. Excessive flow rate settings can cause an overload of filament passing through the nozzle, causing over extruding in 3D printers.

How to Fix Over-Extrusion 3D Printing?

Now that we understand the association between 3D printer over-extrusion and printing temperature, filament diameter, and flow rate, it is possible to employ targeted remedies. Hence, this part has compiled some workable fixes. Check them all and try to avoid repetitive occurrences of this issue.

Adjust Extrusion Multiplier

The extrusion multiplier setting controls the filament flow rate. Currently, most slicers default the extrusion multiplier to 100% (or 1). To address over-extrusion, you can gradually decrease this value by 2.5% to 5% increments.

However, considering the material and setting variations in each print, you can also measure the filament to determine the extrusion multiplier. Start by measuring 120 millimeters along the filament from the nozzle top and mark this length. Then, the 3D printer will be set to extrude 100 millimeters of filament. After that, measure the remaining filament to the marked line, and calculate the filament used. If the 3D printer extrudes 104 millimeters instead of 100 millimeters, you need to reduce the extrusion multiplier by 4%.

Lower Print Temperature

To address 3D print over-extrusion, it's essential to lower and determine the appropriate temperature. However, the optimal printing temperature can vary depending on the type of filament being used. You can refer to the common filament below:

• For PLA filament: 190°C ~ 220°C
• For ABS filament: 230°C ~ 260°C
• For PETG filament: 210°C ~ 250°C

It's generally suggested to reduce the printing temperature in 5°C increments and ensure not to decrease it excessively, as this may result in under-extrusion, leading to insufficient material flow.

Calibrate Filament Diameter

The common filament diameters are 1.75 mm, 2.85 mm, and 3 mm. If the actual diameter during printing is thinner than the specifications, it can be beneficial to manually check the filament diameter.

Take a digital caliper to measure the filament diameter at five different points and calculate the average. Then, enter this measured value into the filament settings in the printer software to calibrate the printing diameter.

Replace Worn Nozzle

Keeping the nozzle clean and in good condition is beneficial to avoid 3D printing over-extrusion. However, if the current nozzle begins to wear, it is advisable to replace it promptly. With prolonged use, the worn nozzle diameter increases and can cause a higher filament output during printing. This will aggravate the occurrence of over-extrusion.

You can find more information in our guide to replacing 3D printer nozzles.

Set Proper Nozzle Diameter

The standard aperture of a 3D printer nozzle is 0.4 mm, and the nozzle can be replaced with different sizes. In general, the nozzle diameter can range from a minimum of 0.1 mm to a maximum of 2 mm. However, the choice of nozzle diameter needs to be considered in line with the filament diameter to ensure smooth and non-squeezed extrusion. 

Change a 3D Printer

If the above methods fail to resolve the 3D printing over-extrusion, you may need to think about whether the existing 3D printer is outdated or faulty and requires a new one. When selecting a new 3D printer, it is important to consider precision and stability to minimize occurrences of over-extrusion.

The AnkerMake M5 3D Printer and AnkerMake M5C 3D Printer are good choices, both known for their high precision, capable of printing details with accuracy up to 0.1 millimeters. Furthermore, the extrusion flows of both models are 35 mm³/s and 24 mm³/s respectively, falling within the moderate extrusion speed range. This can help you reduce the likelihood of over-extrusion in 3D printing to a certain extent.

Conclusion

Now, you are familiar with the definition and causes of the 3D printer over-extrusion, as well as the solutions. But prevention remains the best course of action. Opting for a high-performance 3D printer and meticulously adjusting print parameters each time can significantly reduce the occurrence of over-extrusion in 3D printing. If, however, you're still experiencing other problems with 3D printing, you can find more troubleshooting tips and solutions in our common issues guide.

FAQs about 3D Printer Over Extrusion

How to fix over-extrusion on the first layers?

In addition to the previously mentioned fixes, such as adjusting print temperature, calibrating filament diameter, and modifying the extrusion multiplier, it's important to ensure proper bed leveling. This will facilitate smooth filament adhesion and help address over-extrusion issues on the first layers.

Can printer hardware contribute to over-extrusion?

Yes, hardware issues in the printer can contribute to over-extrusion. Problems of extruder wear, poor extruder design, or loose components will cause inconsistent extrusion.

Furthermore, uneven print beds, improperly calibrated nozzles, or unstable printer structures can also lead to over-extrusion.

What are the symptoms of 3D printer over-extrusion?

Over-extrusion examples include:

• Excess material bulging on print surfaces;
• Poor dimensional accuracy;
• Layers that appear squished or overlapping;
• Blobs on outer walls;
• Print lines appear wider than they should be;

What is the difference between under-extrusion and over-extrusion 3D printing?

Under-extrusion occurs when a 3D printer fails to extrude enough filament, leading to weak, incomplete, or brittle prints with gaps or missing layers. Over-extrusion happens when too much filament is extruded, causing blobs, stringing, or rough surfaces.