Drawing occurs when tiny plastic threads remain on the 3D print. Usually, this is because when the nozzle is moved to a new position, the plastic comes out of the nozzle. Fortunately, in Cura, there are several settings that may help solve this problem. To solve the problem of wire drawing, the most common method is "back drawing". If the ejection is on, the wire in the nozzle will be pulled back after the extruder finishes printing one area of the model. When printing again, the plastic will be pushed back into the nozzle and extruded from the top of the nozzle. To confirm that rewinding is on, click "advanced rewinding"

The most important setting of pullback is the pullback distance. It determines how much plastic will be pulled back from the nozzle. Generally speaking, the more plastic is pulled back from the nozzle, the less prone it is to sag when the nozzle moves. The normal withdrawal length is set in the range of 6-10 mm. Specific also depends on the characteristics of consumables.

The next setup related to pumping back is the pumping speed. It determines the speed of wire pulling away from the nozzle. If the pumping back is too slow, the plastic will hang out of the nozzle and begin to leak before moving to a new position. If the withdrawal speed is too fast, the wire may be disconnected from the plastic in the nozzle, and even the rapid rotation of the driving gear may scrape off the surface of the wire. There is a range, the pumping effect is better, between 3600-6000 mm / min (60-100 mm / s). The most ideal value, according to the actual material you use. Therefore, you need to do experiments to determine whether different speeds reduce the amount of wire drawing.

If you've checked the pullback settings, the next most common cause of wire drawing problems is extruder temperature. If the temperature is too high, the plastic in the nozzle will become very viscous and flow out of the nozzle more easily. Then, if the temperature is too low, the plastic will remain hard and difficult to squeeze out of the nozzle. If you think your pumping setting is correct, but this problem occurs, try lowering the extruder temperature by 5 to 10 degrees. This will have a significant impact on the final print quality. The normal printing temperature of PLA is between 190-210. If the temperature is set too high, the melting ratio of consumables will cause that the pumping is not clean enough, so it is easy to draw. Therefore, the proper printing temperature setting of nozzle has a direct impact on the effect of printing model.

As we discussed above, drawing takes place in the extruder, moving between two different positions. During the movement, the plastic drops from the nozzle. The moving distance has a great influence on the production of wire drawing. The short travel is fast enough that there is no time for the plastic to fall back from the nozzle. Then, large distance movement is more likely to lead to wire drawing. This can't be changed in Cura（ Note: Fortunately, simplify 3D includes a very useful feature to make the mobile path as small as possible. The software is very intelligent, can automatically adjust the moving path, to ensure that the nozzle suspended moving distance is very small. In fact, most of the time, the software can find the right path to avoid moving far in the air. This means that there is no possibility of wire drawing because the nozzle is always over the solid plastic and does not move to the outside of the print. To use this feature, click the "Advanced tab" to turn on the "avoid moving out of contour" option. So if you are interested, you can expand and learn to use S3D. Of course, if you can, it will be more perfect. So if you are interested, you can learn how to use simplify3d by yourself.