Q6.Filament stringing or oozing

1.Insufficient retraction distance

The most important setting for retraction is the retraction distance, which determines how much filament is retracted from the nozzle during each retraction. Generally, the more filament that is retracted, the less likely stringing will occur. Most direct drive extruders require a retraction distance of 0.5-2.0mm, while some Bowden extruders may require a retraction distance of up to 15mm. If  filament stringing happens, please try increasing the retraction distance by 1mm at a time.

2.Slow retraction speed

The retraction speed is another important setting that determines how quickly the filament is retracted from the nozzle. If the retraction speed is too slow, the molten filament may still flow out of the nozzle. If the retraction speed is too fast, it may cause the molten filament to separate from the unmolten part or the extruder gear to chew up the filament. A retraction speed between 20-100mm/s is usually ideal and may require some experimentation to find the optimal speed.

3.High printing temperature

If both retraction settings are appropriate, the next most common cause of filament stringing is printing temperature being too high. At high temperatures, the filament inside the nozzle becomes very sticky and can easily ooze out. However, if the temperature is too low, the filament may be difficult to extrude. If filament stringing still occurs after checking the retraction distance and speed, try lowering the printing temperature by 5-10 degrees Celsius to see if it improves the issue.

4.Long travel moves

The distance between travel moves can also have a significant impact on filament stringing. Short travel moves may not provide enough time for the molten plastic to flow out of the nozzle, while long travel moves can easily cause stringing. Some slicing software may have settings that can help avoid long travel moves, which should be explored if filament stringing persists.