Lots of folks are having issues with printing with filaments like ABS.
I also have been printing with ABS and from the begining I used the dryer to dry the filament before starting to print.
Basically I want the moisture lever to be below 20%.
But, as the filament comes directly from the dryer, it takes a long route to the printer. And, if I leave the filament in place, as I will start printing another project the next day, the result is a print job where the first layers are not as smooth as the later layers. Obviously this is caused because the filament that is still in the lines to the printer is not being dryed by the dryer and hence does not loose the moisture it has gathered over night.
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So basically I do need to retract the filament if I don't know how long it will take before I will start the next project to print in ABS.
Same goes for any other hygroscopic filament