I'm trying to tune my still quite new Ultimaker 2 and am using this quite tricky item for it: https://www.thingiverse.com/make:61855 .
So far I've tried lowering speed, playing with different layer heights, slightly lowering the temperature, using support, and disabling "Combine Everything Type-A".
Plastic: Faberdashery black PLA. Printing at 210. 50mm/sec.
What I am seeing at all settings is ugliness on the front right sight of the print. I'm not sure whether this is a printer issue or a cura/slicing issue.
Picture of left side: http://damad.be/joost/attic/priv/um2_c_left.jpg
Picture of right side: http://damad.be/joost/attic/priv/um2_c_right.jpg
Do you have an idea what might be going wrong here? The left side clearly shows that the UM2 can print this properly without support, the right side on the other hand looks really ugly.