Printing small gear

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 ?

inaki.

Try using the fan.

We made these using Slic3r and Pronterface. Fan helped immensely.
We also used the Fine ABS setting supplied by Lulzbot. Infill was set pretty high too.

We tweaked back the first layer height so it wouldn’t squish out so much too.

We’ve been printing a few months now with a gear we printed.

Also, print a plate of multiple ones may let it cool better, if you aren’t using a fan.