I am printing this one:
herringbone_small_gear-1.1-highres.stl (from Lulzbot ftp)
It prints well on all sides except the back side (the side that looks to the back of the printer). There the gear threads look fuzzy and dirty. The part is not usable at all.
I have repeated the print two times with identical results.
I am using Simplify3D TAZ 4 default profile, ABS, with no FAN.
What can be wrong ?