Frequently Asked Questions

important retraction settings as well as several other settings that
can be used to combat stringing, such as the extruder temperature
settings.
(1) Retraction distance
The most important retraction setting is the retraction
distance. This determines how much plastic is pulled out of the
nozzle. In general, the more plastic that is retracted from the
nozzle, the less likely the nozzle is to ooze while moving. Most
direct-drive extruders only require a retraction distance of 0.5-
2.0mm, while some Bowden extruders may require a retraction
distance as high as 15mm due to the longer distance between the
extruder drive gear and the heated nozzle. If you encounter
stringing with your prints, try increasing the retraction distance by
1mm and test again to see if the performance improves.
(2) Retraction speed
The next retraction setting that you should check is the
retraction speed. This determines how fast the filament is retracted
from the nozzle. If you retract too slowly, the plastic will slowly
ooze down through the nozzle and may start leaking before the
extruder is done moving to its new destination. If you retract too
quickly, the filament may separate from the hot plastic inside the
nozzle, or the quick movement of the drive gear may even grind
away pieces of your filament. There is usually a sweet spot
somewhere between 1200-6000 mm/min (20-100 mm/s) where
retraction performs best. Thankfully, Simplify3D has already
provided many pre-configured profiles that can give you a starting
point for what retraction speed works best, but the ideal value can