How to Fix the Issue of PETG Stringing
PETG Stringing: Image Source: howto3dprint.net
PETG Stringing - What is it?
Thermoplastic items may be accurately and affordably manufactured with FDM 3D printing. The FDM procedure entails melting a filament, extruding it from a nozzle, and depositing it in 2D layers.
Unfortunately, any machine that works with hot liquid plastic is likely to experience trouble from time to time. Stringing is one of these issues, which occurs when extra molten material seeps from the printer nozzle as it moves from one place to another. This leakage causes tiny plastic strands to collect across the building, occasionally rendering the part useless.
Stringing can happen with any kind of filament, but it is prevalent in PETG since it has a high melting point and needs an elevated nozzle temperature to flow and print well. On the other side, stringing is less likely to occur with high-viscosity materials.
How to Fix PETG Stringing?
1. Temperature of Nozzle
The temperature of Nozzle: Image Source: wevolver.com
Preventing PETG stringing begins with choosing the proper nozzle temperature for your PETG filament. It may take some time to figure out this method. Too much heat in your extruder causes the filament's viscosity to be too high. As a result, your extruder will produce more filament, resulting in stringing and blobs when the nozzle must move from one area of the print to another.
For printing with PETG filament, the average nozzle temperature range is between 210°C and 250°C. However, this will change based on your 3D printer and the brand of filament you're using. To be specific, check the suggested printing temperature ranges provided by the manufacturer. To determine which temperatures are ideal for your particular setup, we advise utilizing a temperature tower to verify the print quality at 5- to 10-degree intervals.
2. Retraction Distance
The retraction distance is yet another setting that needs to be tested before it is perfected. The length (in millimeters) that the filament is retracted into the nozzle by the extruder is known as the retraction distance. Less filament is retained each time the nozzle moves around the print bed. A low one causes greater stringing and extrusion than a high retraction distance.
Similar to retraction speed, you will need to experiment to determine the ideal retraction distance settings. Test prints can be used to gradually extend your retraction distance. Continue doing this until you noticeably see less stringing and globbing in your PETG 3D printing.
3. Print Rapidly
The print speed of a 3D printer describes how fast the print head moves during printing. Better print quality is typically achieved with slower printing speeds. This is possible because the printer has enough time to accurately extrude the material into the desired location. However, fast print speeds make it challenging for the 3D printer to extrude and put the melted filament precisely.
Besides, speeding up your print can be helpful if you're experiencing PETG stringing or blobbing problems. This is due to the fact that sluggish print speeds leave your extruder stationary for a longer period, giving your nozzle more opportunity to leak filament accidentally. The ideal printing speeds for PETG filament are typically between 40 and 60 mm/s.
3D print speed should not be your major concern for PETG stringing issues, so you should experiment with your settings until you find the ideal speed. While quick print speed may help with stringing, it might also lead to other issues.
When printing PETG, it is generally preferable to keep your print speed to no more than 60 mm/s. First, adjust your temperature and retraction settings; this usually results in the greatest benefits.
4. Combing
Combing: Image Source: reddit.com
Combing is a feature that lets you modify your extruder's travel patterns if at all feasible; it never crosses any open space. Your slicer software recalculates the extruder's motion when combing is enabled. The new route makes sure that it travels as little as possible of the paths outside of your actual print area.
Although it may extend the length of your print job, this method of avoiding PETG stringing works well. Combing can be a good solution if adjusting the retraction parameters, printing temperature, and speeds have not succeeded in reducing your stringing and blobs.
5. Coasting
You can also attempt coasting if you've tried the previous options and still have trouble with PETG stringing and blobbing. Coasting turns off the extruder motor just before the printer is ready to pass over space.
Any excess filament in the extruder that would often result in stringing will be used to complete the current print portion, according to the plan. Doing this will empty the extruder before the printer completes the print portion.
This might be effective if your stringing problem is severe, but it frequently results in a line of under-extrusion in specific regions of your print. This results in issues with the print's structure and appearance in that area. Because of this, it is not the best option for PETG stringing.
Coasting in Cura
Coasting in Cura is a great way to improve your print quality and speed. By disabling the retraction while the print head is moving, you can eliminate stringing and improve your print quality. This feature is available in Cura 2.6 and above.
To enable coasting, open the Cura settings dialog and navigate to the Extrusion tab. Check the box next to "Coast at end" and enter the amount of time you want the print head to move before retracting. The default value is 0.5 mm.
You can also enable coasting in the infill settings. This is useful for prints that have a lot of infill, such as objects with large voids. To enable coasting for infill, open the infill settings dialog and check the "Coast at end" box.
6. Speed of Retraction
Another crucial element in lowering PETG stringing in your 3D printing is your retraction settings. Retraction speed describes how quickly the extruder retracts the filament as it moves from one place to another. Since the extruder does not retract back quickly enough to stop filament flow, low retraction speed is typically to blame for oozing and stringing.
Your retraction should begin at a speed of 25mm/sec. The ideal retraction settings will change from 3D printer to 3D printer. To find the best settings for your machine, you'll need to do a little experimentation. Use a test print and gradually increase the retraction speed (2–5mm/sec) until you see a noticeable improvement.
7. Vertical Lift
The vertical lift function often referred to as a Z-hop in some slicers, separates the 3D print from the nozzle during retraction. This is accomplished by raising the print head (or lowering the build plate). Since the nozzle doesn't touch the print as it moves, this can help you prevent strings. This will avert any oozing filament from having a chance to anchor to one print area and ooze material to the adjacent print area.
Software for Preparing 3D Models
It's time to design your favorite designs before buying PETG filament. Determining which 3D modeling and printing software is best for you may take time and effort. A good example of an easy to use 3D design software that you can use to create your designs is SelfCAD.
With SelfCAD, you can create 3D models using the various tools like freehand drawing and sketching, 3D shape generators, and easy to use selection modes, . Experts and beginners can both benefit from the program, and it usually does not require weeks of hard work.
The software also comes with powerful 3D sculpting tools users can use to sculpt their designs and generate realistic 3D characters. If you would like to render your designs, SelfCAD also has an in-built 3D rendering software that you can use to generate realistic renders of your designs with ease.
SelfCAD also comes with an in-built slicer that you can use to generate the gcode that you will send to your 3D printer. You can also use it to concert STL to gcode.
Conclusion
Stringing is a typical issue with PETG 3D printing filament and can significantly lower the quality of your prints. The key to getting PETG prints with a smooth surface finish is finding out the proper 3D printer parameters. Each 3D printer and filament combination has its own particular requirements and settings.
If your PETG begins to string or glob, you can alter the printing temperature, retraction, and speed. Invest in high-quality PETG brands, such as Overture, to minimize extrusion problems. Remember to keep your 3D printer's nozzle clean and keep your filament dry when not in use.
Enjoy powerful modeling, rendering, and 3D printing tools without the steep learning curve.
Need to learn 3D modeling? Get started with interactive tutorials.