3D Print Stringing: What causes and how to fix it?

Do you ever find that your 3D prints don't always turn out perfect? Are they plagued by 3D print stringing or other imperfections, no matter how many times you re-calibrate and tweak the settings? Then this blog post is for you!

In this article, we'll discuss what causes stringing in 3D printing, and most importantly – how to fix stringing 3D printers so that your prints come out sleek and professional every single time.

So whether you're just starting with a 3D printer or are an experienced user looking for more advice and tricks on the wonderful world of 3D printing, read on to learn everything about reducing stringing in your finished products.

What causes stringing in 3D printing?

If you’ve ever watched a 3D printer in action, you may have noticed small strings of plastic extruding out from the nozzle, this phenomenon is called stringing.

There are several factors that can contribute to stringing in 3D printing, including:

• Extruder temperature: If the extruder temperature is too high, it can cause the filament to melt excessively and ooze out of the nozzle. This can be particularly problematic with materials like ABS and nylon, which have a higher melting point.
• Retraction settings: Stringing can also be caused by insufficient retraction settings. Retraction is the process of pulling the filament back into the extruder to prevent ooze. If the retraction distance is set too low, or if the retraction speed is set too slow, it can cause the filament to continue oozing out of the nozzle and form strings.
• Nozzle size: Using a nozzle with a larger diameter can also cause stringing, as it allows for more filament to be extruded at once.
• Print speed: Higher print speeds can also cause stringing, as the filament has less time to solidify before being extruded again.
• Cooling: Some materials string more when cooling is poor, like the low-quality cooling of the print head.

To reduce stringing, you can try adjusting the extruder temperature, retraction settings, print speed, and nozzle size, or adding a cooling fan to the print head to help the filament solidify more quickly. Experimenting with different settings and observing the results can help you find the best combination of settings for your printer and filament.

How to fix stringing 3D printer?

To help you understand how to fix this issue and keep your prints looking their best, let’s dive into it.

Adjust the temperature of your 3D printer

3D printing stringing can occur when the filament is too warm and starts to melt before it's supposed to, which causes it to droop and leave strings behind. In this case, you can try decreasing the temperature of the hot end (the part of the printer where the filament is heated and extruded) by a few degrees and see if that helps.

You also can adjust the temperature of the bed if your printer has a heated bed, if the bed is too hot it can also cause the filament to droop and produce stringing.

However, if the filament is too cool, it can be more difficult to extrude and can cause the nozzle to clog, resulting in poor-quality prints or even a complete failure to print. In this case, you might need to increase the temperature of the hot end.

It's also worth checking the cooling system of your printer and making sure that it's working properly. If the cooling system is not working as it should, it can cause the filament to cool too quickly, which can also lead to stringing.

Keep in mind that the optimal temperature settings may vary depending on the specific filament you are using, so it may take some experimentation to find the settings that work best for your setup. These are the commonly recommended temperatures for some of the most common filaments:

• PLA: 180-220 °C
• ABS: 200-250 °C (90-100 °C print bed)
• PET: 215-235 °C
• TPE: 210-240 °C (20-70 °C print bed)
• PVA: 160-190 °C (60 °C print bed)
• TPU: 230-250 °C (60 °C print bed)

Adjusting your retraction speed and distance settings

When adjusting the retraction settings on a 3D printer, there are a few factors to consider.

• Retraction distance refers to the amount of filament that is pulled back into the extruder when the printer moves from one location to another without extruding.

When setting the retraction distance, you'll want to make sure that you're not pulling back too much filament, as this can lead to stringing or oozing, which can leave unwanted filaments on your printed object. Conversely, if you don't retract the filament far enough, the filament can drool out of the nozzle, again resulting in stringing or oozing.

The best retraction distance can vary depending on the filament that you're using and the details of your print. For example, you might need to use a larger retraction distance when printing with a flexible filament than when printing with a rigid filament. However, typically retraction distances between 0.5-1mm are a good starting point.

• Retraction speed, on the other hand, refers to the speed at which the filament is pulled back into the extruder.

When setting the retraction speed, you'll want to make sure that you're pulling the filament back quickly enough to prevent oozing, but not so quickly that the filament is torn or jammed in the extruder. The best retraction speed will depend on your printer and the filament you're using, but typically speeds between 20-40mm/s are a good starting point.

Clean the Nozzle Before Printing

Cleaning the nozzle of your 3D printer before starting a print can help ensure that the filament is extruding correctly and that the print quality is as high as possible.

Here are a few methods to clean the nozzle of your 3D printer:

• Cold pull method: This method involves heating the nozzle to the temperature at which the filament you're using melts, then using a piece of the same filament to push through any debris that may be clogging the nozzle. Once the filament is extruded, allow it to cool, and then use a pair of pliers to pull it out. The debris will come out with the filament.
• Needle method: This method involves using a thin, stiff wire (like a needle) to manually clear out any debris that may be clogging the nozzle. Be careful not to damage the nozzle or scratch the internal walls of the hotend.
• Chemical method: Use special cleaning solutions like Acetone, alcohol, or even some detergents. However, it's important to note that some filaments may react to certain chemicals, it's recommended to check with the filament manufacturer or do a test on a small piece before using it.

3D print stringing test model

When you tried the solutions above, you can 3D print this model to verify bridging parameters. Download free now!

High-Quality 3D print setting to prevent the stringing 3d printing

Choosing a best 3D printing software can help you to prevent 3D printer stringing. If you are a Creality 3D printer user, it's highly recommended to use Creality Cloud. It offers the best default setting for your 3D printers.

Conclusion

All in all, reducing stringing on 3D printers requires some trial-and-error as well as careful attention both to temperature and retraction settings. With some experimentation, though, anyone should be able to find an ideal combination that ensures their prints come out looking great every time!

For those who are new to 3D printing or just having trouble getting rid of pesky strings, hopefully, this article has provided insight into why they occur and how they can be prevented--so happy printing!