Stringing in 3D Prints: What it is And How to Prevent it.
Prevent Stringing in 3D Prints: Image Source: howto3dprint.net
Stringing happens when the small plastic string is left behind on a 3D-printed model. Stringing is also known as oozing, whiskers, or hairy prints. When the extruder moves to the new location, plastic moves out from the extruder; this happens when the molten material accidentally leaks out from the nozzle onto the build area, affecting the print quality. This is called oozing, and it leads to the issue of 3D print stringing.
Fortunately, there are several settings of the 3D printer that help prevent the stringing in 3D prints. High-temperature filaments such as PETG and others like ABS and PLA also experience the stringing effect. This article discusses the various solution for reducing and eliminating the stringing problems. Simple slicer settings or some of the common steps can effectively mitigate the stringing issues.
Different Methods for Preventing Stringing in 3D Printing
1. Retraction Settings
There are many solutions for avoiding the stringing problem, but first, check the retraction setting. Retraction means pulling back the filament into the nozzle when the extruder finishes one part of the printing. After this, the extruder moves to the next location and starts printing again by pushing out the filament from the nozzle. For retraction settings, there is an option of “Edit Process Settings.”Click on that or click on the Extruder tab. This ensures the retraction option is enabled. Keep an eye on the retraction distance and speed!
Retraction Distance
Retraction distance: Image Source: 3dprinting.stackexchange.com
Retraction distance is the most important setting, which determines the amount of filament retracted from the nozzle. In general, if more filament is retracted from the nozzle, then there are fewer chances of oozing the nozzle while moving.
If you observe the stringing of the object, try increasing the retraction distance by 0.2 mm every time and recheck the printer's performance. Do this until you get the perfect result. Remember that you should not increase the stock retraction distance by 1 mm before contacting Tractus3D support. This retraction distance should not be set too large; otherwise, it will clog the nozzle.
Retraction Speed
Retraction speed determines the speed of the filament, which is retracting from the nozzle. If the retraction speed is too slow, the filament will slowly drip down from the nozzle. This causes the leaking of the nozzle before the extruder moves to the next part of printing. When the retraction speed is too fast, this causes the separation of the filament inside the nozzle.
Even the grinding of the filament pieces is possible through the driver gear's quick movement. Hence the best option of retraction speed for this is between 1200-6000 mm/min. In this range, retraction performs best. Many ideal values are possible depending on the material used. Different speeds for distinct materials can be found by changing the settings.
2. Set The Right Temperature
Another factor responsible for excessive stringing is the extruder temperature. If the temperature is too high, the filament inside the nozzle will be melted and thus leak out from the nozzle. When the temperature is too low, the filament remains in a solid state, making it difficult to extrude from the nozzle. Try different temperatures; start by decreasing the temperature by 5 degree Celsius each time. This will have an impact on the final print quality. “Edit Process Setting” has the option of Temperature Tab. Here you can edit the temperature by selecting the required temperature from the list.
3. Travel Movements
Stringing happens when the extruder moves between two different locations. During this time, the plastic material starts oozing out from the nozzle. The length of this travel movement can considerably impact the stringing of the object.
A higher length means there is enough time for the filament to ooze out of the nozzle. If the travel time is short, the movement will be quick enough, and there will be less time for the filament to ooze out from the nozzle. However, there are settings for reducing the distance of these movements.
There is software that can automatically adjust the travel distance of the nozzle such that it requires a very short distance to travel over an open space. In some cases, the software automatically finds the distance where the travel path is less or which can avoid the crossing of open space altogether. This ensures there is no possibility of creating a string, as the nozzle will always be on top of the solid plastic, and there is no need to travel outside that part. To activate this feature, click on the Advanced Tab and then enable the “Avoid crossing outline for travel movement” option.
4. Movement Speed
By increasing the movement speed of your 3D printer, you can reduce the amount of time the extruder will get to ooze out the filament while moving between the two points. By clicking on the movement speeds tab of your machine, you can verify the speed of your device.
The X/Y axis movement speed represents side-to-side movement speed. This is directly related to the time the extruder takes to move over the open air. If the machine can handle the higher speed, you may reduce the stringing between the parts by increasing this speed.
5. Thoroughly Cleaning the Nozzle Before Printing
If you are printing using the same type of filament for a long time, there are more chances of leaving filament residue inside the nozzle. This residue leads to the stringing problem in your object, as the filament strands will try to stick to the surface of your 3D printed part.
It is necessary to clean the nozzle of your 3D printer before printing to avoid this problem. It removes all the dirt and any previous filament residue from the nozzle. There are various methods available for cleaning your nozzle.
6. Keep the Filament Moisture-Free
Some filaments, such as PLA, absorb more moisture compared to the ABS filament. If moisture is present in the filament, it will turn into steam as the filament starts heating. This steam may get mixed with the plastic and thus increasing the chances of oozing out of the filament from the nozzle. Therefore stringing affects your 3D prints. Hence, it is necessary to keep your filament in a moisture-free environment, for example, a plastic box.
Best Software for Preparing 3D Models for 3D Printing: SelfCAD
With so many options for 3D printing software available, it can be difficult to decide which one is the best for you. Fortunately, we can recommend SelfCAD as the best 3D printing software for beginners and experienced users alike. SelfCAD is a powerful and easy-to-use 3D modeling software that offers a range of features and tools to create stunning 3D models that ready for 3D printing. You can use it to design, sculpt, render, and slice 3D models quickly and easily without the need for an additional software.
SelfCAD has a user-friendly interface, powerful modeling tools, and a variety of features that make it easy to create stunning 3D models. The online slicer of the software is easy to use and it supports a wide range of 3D printers, making it easy to get started with 3D printing.
If you have STL files that you would like to edit, you can also also import to SelfCAD and modify it based on your needs. For example, you can reduce the number of faces using the Simplify 3D tool as shown in the video below. You can also remove watermarks in a design easily without spending a lot of time, as shown below.
Conclusion
You may encounter many problems with your 3D printer, and stringing is one of them. A combination of proper slicer settings and the maintenance of the 3D printer can prevent it. If you are unable to find the root cause of the stringing problem in your 3D printer, then you can do the physical maintenance of your printer. Physical care means storing the filament in dry places, cleaning the nozzle, and adjusting the slicer settings. Even if these factors are not the cause of the stringing problem, maintaining them can surely improve the print quality of your future printing process.
Also, the default settings of the slicer need to be slightly changed, and no radical altercation is required to achieve the best results. Therefore, adjusting the print parameters within the slicer software gives complete control over the printing process and avoids stringing. The main parameters for controlling the stringing problems are retraction and temperature settings. Finally, it is crucial to notice that these problems, such as stringing, can be mitigated by post-processing techniques such as sanding off the 3D printed objects.
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