3D Printing Stringing | Easy Solutions

3D Printing Stringing

Stringing in 3D printing occurs when melted plastic oozes from the printer nozzle during a travel move and solidifies on the printed parts, resulting in thin strands of plastic that resemble cobwebs or hair.

Ideally, the nozzle should not deposit plastic during a travel move, but in practice, molten plastic often leaks onto unintended areas, causing stringing.

One of the primary causes of stringing in FDM printers is incorrect retraction settings, which fail to pull the plastic back into the nozzle when it moves to a new location. Another cause is setting the hot end temperature too high, which can cause excessive melting and oozing of plastic. Even materials like PETG, which require high temperatures for melting, are notorious for stringing. PLA and ABS can also experience stringing issues.

PETG Stringing can also be an issue for a lot of printing enthusiasts out there, but I think I got you guys covered as well.

This article aims to discuss the factors that cause stringing in 3D printing and suggest practical solutions to eliminate this problem.

Whether you are a beginner or an experienced user, this article will provide helpful advice and techniques to help you consistently minimize stringing and produce high-quality prints.

Keep reading to discover how to reduce 3D Print stringing.

Allow Retraction 

When a 3D printer travels between two printed parts during a print, it may leave unwanted plastic in between. To prevent this, it is essential to use the retraction setting. This feature pulls the filament back slightly with the feeder to avoid any plastic leakage from the nozzle during travel moves.

The retraction setting is typically enabled by default in Cura, but double-checking is advisable to ensure it is on. You can verify this by checking the Layers view in Cura, where small dark blue vertical lines represent the retractions in the print. To further minimize stringing, you can adjust the retraction length or speed.

However, even with retraction enabled, tiny plastic strands can still appear where they are not wanted. Keep reading to discover additional methods for reducing stringing in your prints.

Retraction Distance

The most crucial retraction setting is the retraction distance, which governs how far the filament is pulled back. Typically, a longer retraction distance reduces the chances of encountering 3D printer stringing. However, retracting too far may cause the filament to be unavailable in the hot end during printing.

The retraction distance required may vary depending on the type of extruder you are using. For instance, a Bowden setup’s extruder will typically require a higher retraction distance due to the long distance between the nozzle and the drive gear.

You may need to conduct test prints to determine the appropriate retraction distance. You can try using a retraction test print, which prints quickly and uses minimal filament.

Retraction Speed 

The retraction speed is responsible for how quickly the filament is pulled back. A faster retraction speed indicates a lower possibility of 3D printer stringing because the filament is retracted before it starts to ooze. However, retracting too quickly may cause the filament to disconnect from the other part inside the nozzle, leading to nozzle jams or incomplete filament deposition.

Therefore, it is essential to find the optimal retraction speed that lies between slow and fast. The sweet spot may vary depending on the printing material, and you may need to perform several test prints to determine the perfect retraction speed.

If you’re still unsure, Simplify3D can be a helpful tool. This software includes pre-configured profiles that provide an excellent starting point for the best retraction speed.

Filament Drying 

To avoid 3D printing stringing, ensuring that the printing material is in optimal condition is essential. Filament that has absorbed moisture can lead to several issues, such as nozzle jams, weak parts, under-extrusion, blobs, and stringing.

When the filament absorbs moisture, it can result in stringing because the moisture trapped in the material evaporates inside the printer nozzle, increasing pressure that pushes out the molten plastic in undesired locations.

To prevent this problem, storing the filament in an airtight container with a desiccant is crucial. Additionally, the filament can be dried using a dedicated filament dryer, a food dehydrator, or an oven.

Keeping the Nozzle in Good Shape

Stringing in 3D printing can also be caused by a clogged nozzle. Over time, material buildup or residue may obstruct the FDM printer nozzle, leading to poor performance of the hotend.

To avoid this, regularly removing residue from the nozzle is necessary. Different tools can be used to unclog the nozzle, including a brass wire brush, a needle, a heat gun, or a specialized cleaning filament. In addition, immersing the nozzle in acetone can remove any ABS residue.

Adjust the Print Temperature 

Filament that is too runny can cause 3D printer stringing. To combat this issue, you can lower the temperature in the hotend to reduce the amount of melting. However, it’s essential to strike a balance between preventing stringing and maintaining proper material flow. Using too low of a temperature can cause under-extrusion.

Adjust the print temperature in increments of 5 °C until you find the ideal temperature for your print.

Here are the commonly suggested temperatures for some of the most frequently used filaments:

Material Printing Temperature (°C)
Print Bed Temperature (°C)
PLA 180-220 N/A
ABS 200-250 90-100
PET 215-235 N/A
TPE 210-240 20-70
PVA 160-190 60
TPU 230-250 60

Modify the Print Speed

Adjusting printer speed settings is a valuable technique to prevent 3D printer stringing. Two key parameters that can be adjusted are print speed, which affects the speed at which material is deposited, and travel speed, which determines the speed at which the printhead moves over empty space.

Print speed does not significantly impact stringing but is closely tied to print temperature. Higher print speeds require higher temperatures to melt the material quickly enough. Therefore, your maximum print speed may also be reduced if you have already reduced your print temperature to prevent stringing.

Travel speed, on the other hand, is a more relevant speed setting for preventing stringing. Slow travel speeds increase the likelihood of stringing because the printhead has more time to dangle an oozing nozzle over the parts below.

By increasing travel speed, the nozzle spends less time moving through open space and has fewer chances to drip excess material onto the printed parts.

Go For Advanced Cura Settings

Some advanced Cura settings can be used to minimize stringing for 3D models or materials that are prone to this issue, such as thin-walled models made from PETG.

  • By decreasing the “Max Comb Distance With No Retract” setting, stringing can be greatly reduced. However, this may increase print time and potentially degrade top surface quality in some cases. As a compromise, a maximum comb distance of 8 mm is recommended for Ultimaker PETG.
  • Disabling the “Fill small gaps” setting can also reduce the number of travel moves and consequently decrease stringing. However, it is important to carefully review the print preview, as this may also remove essential features from the top surface and impact the object’s mechanical properties.

With the right settings, minimizing the amount of stringing is possible.

Stringing 3D Printing | Lets Fix It For Once and For All


The Conclusion

To sum up, 3D printing stringing can affect the quality of prints and cause material waste. However, proper temperature, retraction, speed settings, appropriate filament selection, and regular nozzle cleaning can prevent or minimize it. By implementing these techniques, 3D printing enthusiasts can achieve high-quality prints with minimal stringing, resulting in successful and efficient production.

Thanks for reading. Have a lovely day.

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