Over extrusion is when your 3D printer extrudes too much material, and it can result in parts that have dimensional inaccuracies, oozing blobs, drooping layers, and strings. If you are experiencing any of these symptoms, then you are likely dealing with an over extrusion issue.
Do not worry though, this issue is common in all filament and printer brands.
But what causes over extrusion? Some common causes of over extrusion include:
- Extrusion multiplier settings being off
- Too high of a print temperature
- Too high of a flow rate
- Incorrect filament diameter
- Incorrect nozzle size
How do we fix over extrusion? The good news is, is that there are plenty of ways to fix the issue, which we have highlighted below.
Adjust your extrusion multiplier settings
The extrusion multiplier controls the amount of filament coming out of the nozzle. You can usually tell if the over extrusion is due to the extrusion multiplier if you are seeing frequent nozzle jams or large layers.
To fix the extrusion multiplier, reset it by going into the filament settings in your slicer software. The default setting is 1, but you can adjust it anywhere between 0.9 and 1.1 (depending on your filament type).
You should also be able to edit your extrusion multiplier settings directly from your printer menu. The values in the printer menu will range from 90 to 100, but you can adjust the value to suit your needs.
- Adjust your extrusion multiplier settings. Do not make any drastic changes. Instead work in intervals of around 2.5%, and observe how it changes your final print.
When your print temperature is too high, it causes more filament to melt at a faster rate. This leads to over-melted filament flowing uncontrollably out of your printer nozzle, which can cause low quality prints.
When the filament is too hot, the material can “blob out.” Lowering the printer temperature can help to control the amount of printer material that is coming out and allows the material to form more precise layers; however, don’t let the temperature get too low because that can lead to under extrusion.
- Lower your printer temperature. Be careful not to lower the temperature too quickly; instead, lower it by about 5°C at a time.
Lower your flow rate
Too high of a flow rate can wreak the dimensional precision of your print because the upper layers will have larger dimensions than the bottom layers.
Lowering the flow rate is best accomplished through trial and error because the ideal flow rate will need to be determined for each filament. This involves picking a model and printing it with different flow rates until your find the best result.
- Lower your flow rate. It is advised that you lower the flow rate in intervals of 5%.
Determine the correct filament diameter
If you have the wrong filament diameter set in your slicer, the printer will extrude the filament at a higher rate, which leads to over extrusion. Some of the standard filament diameters are 1.75, 2.85, and 3mm.
Determine the correct nozzle size
The good news with nozzles is that they are easily interchangeable. The standard nozzle size is 0.4mm, and these are ideal for most projects. If you are not getting the correct results with your current nozzle, try a smaller nozzle to help bring out more intricate details of your design without facing any over extrusion.
- If you are experiencing over extrusion with your current nozzle, try switching the nozzle out for a different one and print again.
Over extrusion may be a common problem, but it is still an unwanted one. Over extrusion can cause your parts to print with oozing blobs, droopy layers, and strings. This issue is caused by a variety of items such as too high of a print temperature, but a few simple fixes can get you back on track and printing in no time.