There are 4 reasons for the problem:

1. Insufficient pumping distance

A: The most important setting in retraction is the retraction distance, which determines how much plastic is drawn back from the nozzle during retraction. Normally, the more plastic that is drawn back from the nozzle, the less noticeable the drawing condition will be. Most proximity extrusion systems only require a drawback distance of 0.5-2.0mm, but some bowden extruders require a drawback distance of 15mm due to the distance of the extrusion wheel from the nozzle. If your printer has the phenomenon of pulling, try to increase every 1mm to test the pullback distance.

2. Pumpback speed is too slow

A: Another important setting in pumping is the pumping speed, which determines how fast the consumables are pumped away. If the drawback speed is too slow, the melted consumables will still flow out of the nozzle. If the drawback speed is too fast, there is a risk that the unmelted part of the consumable will separate from the melted part, or that the extruder wheel may bite off a piece of consumable. There is usually an excellent retraction speed between 20-100mm/s, which requires several attempts.

3. Printing temperature is too high

A: After checking the above two items, the next most common cause is high temperature of the extrusion head. If the temperature is too high, the consumables inside the nozzle will become very sticky and flow out of the nozzle easily, but if the temperature is too low the consumables are harder to extrude. If you are sure that the pumping distance and the pumping speed are appropriate, and you are still experiencing pulling, you can try to lower the temperature of the extrusion head by 5-10 degrees Celsius. This will give a noticeable improvement.

4. Excessive distance between traverses

A: The distance between the traversing will also have a great influence on the drawing, short distance movement, the melted plastic does not have enough time to flow out of the nozzle, but the long distance movement is very easy to produce the drawing phenomenon, some slicing software has relevant settings to avoid long distance movement, we can turn on those options.