Cura is one of the best slicing software used in 3D printing for hobbyists and professionals alike. With an easy-to-use interface, compatibility with different printers, and many premium features, it’s the go-to slicing software for 3D printing enthusiasts worldwide. However, often over extrusion can happen in your 3D printer when using Cura, resulting in low-quality prints.
Here are five ways to fix over extrusion in Cura:
- Adjust the print temperature.
- Correct the filament diameter.
- Adjust the extrusion multiplier’s flow rate.
- Adjust the nozzle size.
- Use a different filament.
This article will discuss the above fixes in detail. It will also guide you on what causes over extrusion in 3D print and how to diagnose the problem’s source. Finally, we’ll answer common queries solving printing problems like blobs and under extrusion.
1. Adjust the Print Temperature
Every filament has an optimal print temperature. This temperature is associated with the melting point of the filament and allows it to be molded accurately.
Setting the temperature too high may cause the filament to melt faster, resulting in more liquid escaping from the printer nozzle.
To adjust the printing temperature in Cura, make sure to follow the ideal filament temperature.
- TPU should be printed at a temperature of 220-250°C (428-482°F)
- PLA should be printed at 190-220°C (374-428°F).
With such differences in the printing temperature for both materials, you should carefully adjust the temperature before printing.
Most 3D printers allow you to adjust the printing temperature on the control panel, but you can also use the Cura software to do so. Setting the temperature in Cura will override the manual setting and adjust the temperature command in the GCode file. So, if your printer isn’t getting the right setting, adjust it in Cura instead.
2. Correct the Filament Diameter
Another cause of over extrusion is a filament diameter that mismatches the slicer’s diameter settings. This causes the material to flow through, resulting in blobs or spills.
There are two ways to correct the filament diameter:
- The first way is to measure and adjust the diameter settings on the printer manually. This method is tedious and is only useful for checking whether the filament’s diameter is correct. If the printing specifications and filament diameter match, you shouldn’t have any problems.
- If there’s a mismatch in the printing settings and filament diameter, you can adjust the diameter settings in Cura. To do so:
- Create a “custom material” under the materials section in the Cura software.
- You’ll see a few adjustment options, including filament weight, density, and cost.
- Input the diameter that you want to print at and save the settings.
With so many different filament qualities available in the market, it’s becoming more common for a filament diameter to be a bit thicker or thinner than required. So, as a precaution, always measure the filament diameter before printing, especially if you’re using a new brand.
3. Adjust the Extrusion Multiplier’s Flow Rate
The flow rate of the extrusion multiplier is crucial for determining how much material flows through the nozzle at any given point. Setting this rate too high will cause over extrusion, resulting in more material flowing out at any time frame.
Luckily, you can easily fix this over extrusion caused by the wrong multiplier setting by inputting the right flow rate into Cura software.
The perfect range to set the extrusion rate in Cura is 90-110%. Still, you can adjust it lower or higher depending on the material. However, by default, Cura has the setting at 100%, so you’ll have to change the extrusion rate manually.
Here are the steps to take to adjust the extrusion multiplier flow rate in Cura:
- Open the custom settings in the Cura software.
- Under “setting visibility,” select “expert settings.”
- Select the initial layer flow in the material settings.
- Decrease the flow rate by 2.5-5% gradually until you reach the perfect extrusion setting.
To achieve the ideal extrusion multiplier setting, you’ll have to go through a trial-and-error process whenever you print with a different filament.
In most cases, the perfect extrusion setting will be off by a few percentage points, so you should get close to the perfect setting after an attempt or two.
However, this fix is usually used when there is slight dimensional inaccuracy. If you’re experiencing blobs or spaghetti-type errors, then you’ll have to try a different method.
4. Adjust the Nozzle Size
The diameter of the 3D printer nozzle can affect the speed and quantity of material that comes out when printing. In addition, different filaments require different nozzle sizes, which is why you should change the nozzles, especially if you’re printing with multiple filament types.
The ideal nozzle size for most plastic filaments has a diameter of 0.4mm (0.016in). But, if you’re using a special material or want to print at a higher temperature, you’ll need to use a smaller nozzle.
Finding the right nozzle is a matter of experience and skill. Still, your printing results will drastically improve once you understand which nozzles are right for different materials.
When changing the nozzle, you’ll have the choice between brass, iron, stainless steel, or even ruby-tipped.
Most home 3D printers come with brass nozzles, but if you’re printing abrasive material, then you could opt for a better quality nozzle.
Here are some of the best printing nozzles available on Amazon:
- Micro Swiss MK8 Nozzle Pack: This set of nozzles contains all the nozzles you’ll need to improve your printing from 0.2mm to 0.8mm (0.008in to 0.031in). Made by Micro Swiss, it will fit most 3D printer models.
- Micro Swiss M2 Nozzle: This nozzle comes in the standard size of 0.4mm (0.016in), is made from hardened steel with nickel plating, and contains a limited lifetime warranty. This nozzle can print most filament types without getting damaged, making it perfect for all 3D printing applications.
- Wusteg 3D printer Nozzle Kit: This kit has everything you need for printing with multiple filaments. It contains 20 brass nozzles and five stainless steel nozzles of different sizes ranging from 0.2mm to 0.6mm (0.008in to 0.024in) for the ultimate 3D printing experience. It also comes with an extruder cleaner and tweezers to help you keep your nozzles clean.
5. Use a Different Filament
Sometimes, regardless of how much you tweak the settings in Cura, you’ll still struggle with extrusion. So, if none of the other fixes work to correct over extrusion in your prints, it could be because of low-quality filament.
With so many different filament brands available, many may have different diameters than advertised. This may result in getting the wrong setting in Cura or cause you to use the wrong nozzle size.
Low-quality filaments may also have different melting points and cause you to set the temperature too low or high.
Always choose a reliable filament brand and measure the diameter of your filaments if you’re going to use a different filament brand. The top three filament brands that you can rely on for high-quality prints are:
However, if you’ve found a brand that doesn’t cause over extrusion, you should stick with it.
How To Tell if You See Over Extrusion
Over extrusion is when a 3D printer releases too much material from the nozzle. As a result, it will release blotches of plastic in irregular bursts, resulting in low-quality print models.
Over extrusion may result in inaccurate prints, blobs, or even 3D print “spaghetti.”
Luckily, it’s easy to identify in most cases, but it will persist until the root cause of the problem is resolved.
Here are some indicators that you have an over extrusion problem:
You’ll See Blobs Pushing Out of the Nozzle
This is the worst form of over extrusion and may even result in the “blob of death.” Blobs indicate that the extrusion settings require immediate correction.
Heated plastic can be dangerous and may damage the printing bed, so if the filament is oozing out of the printer in a “blob” form, stop printing immediately and look for the right fix.
In severe cases, the “blob of death” may cause damage to the printer or even fire if not checked in time.
The Filament Will Look Like Spaghetti
Spaghetti is another form of over extrusion where the material will ooze out of the nozzle in the form of a stringy mess, resembling spaghetti.
Spaghetti prints are less common than blobs but still mean that your prints are wasted.
This problem is almost always caused by a printing temperature that’s too high, so try fixing it by reducing the print temperature settings.
The Print Will Not Look As Expected
Dimensional inaccuracy is another issue caused by over extrusion. It often results in larger prints than the specified dimensions caused by the additional liquid oozing out of the nozzle.
It may vary from a slightly larger print to completely inaccurate prints.
The Printer May Jam and Stop Completely
Over extrusion can cause printer jams in certain cases. When your printer jams, it’s usually caused by the liquid oozing out of the nozzle and then suddenly cooling down.
If you notice any of these issues, stop printing until the problem is fixed.
Some of these problems aren’t significant issues and may only cause imperfections. However, a minor issue in 3D printing may get worse over time, so it’s better to fix the problem immediately.
What Level Should My Extrusion Multiplier Be?
The extrusion multiplier lever is best left at the default setting, which in Cura is usually 100. This is the standard rate at which the filament will flow through the nozzle. However, if you need to adjust it for unique materials, don’t go below 90 and over 140.
How Do I Know if My Printer Is Over Extruding?
You’ll know if your printer is over extruding if it releases too much filament in the form of a blob or lines or if it causes irregular prints with dimensional inaccuracy. In most cases, it will result in consistent irregular or low-quality prints.
How Do I Know if My Printer Is Under Extruding?
Under extrusion happens when the printer releases less material than needed or slows the filament release rate. Under extrusion can cause gaps in the layers of your prints and can result in the nozzle getting blocked. In some cases, it will result in air bubbles in the material and weaker prints.
Under extrusion is usually caused by printing at a lower temperature than recommended, so make sure to adjust the Cura settings according to the filament range.
What’s the Best Fix for Over Extrusion in 3D Printing?
The best way to fix over extrusion in 3D printing is to adjust the extrusion flow rate in Cura. Most mistakes happen when printing with different materials without changing the settings to fit the new material.
Check the extrusion settings and adjust the flow rate according to the filament material requirements. You can also adjust the print temperature and use different filaments. Remember that these solutions won’t work if the extrusion flow settings aren’t correct.
Will Printing at a Higher Temperature Cause Over Extrusion?
Printing at a higher temperature than the recommended printing range of each material may cause over extrusion. However, this value will differ for every printing material, so check each material’s setting before printing.
Try lowering the print temperature slightly if you’re still experiencing over extrusion after adjusting the print settings.
Over extrusion in 3D printing can cause material wastage and even cause the printer to get stuck. It’s usually caused by having the wrong extrusion flow rate, too large nozzle size, or printing at a higher than recommended temperature.
Low-quality filaments or a faulty printer can also cause it.
The best way to fix over extrusion in Cura is to correctly set the extrusion multiplier’s flow rate or adjust the nozzle size. You can also change the filament diameter settings or use a better quality filament.
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I started 3D printing since 2013 and have learned a lot since then. Because of this I want to share my knowledge of what I have learned in the past years with the community. Currently I own 2 Bambulab X1 Carbon, Prusa SL1S and a Prusa MK3S+. Hope you learn something from my blog after my years of experience in 3D printing.