On several models that have horizontal or near horizontal overhang I am getting an odd pattern of single threads, even with support (See picture - center of Guantlet). The horizontal area over the overhang is VERY rough. It seems like the way S3D handles this situation is not the best. I have tried several settings with little impact.
The model I am using to illustrate this is the "Gauntlet" from here: http://www.thingiverse.com/thing:596966, from the e-nable initiative. The first picture uses the "built in" supports, but using S3D supports was about the same. Note the "wiggle" pattern and that even on the same layer there is not enough plastic to cover the holes.
I reprinted this model with a process just for these layers using 100 outline shells so there is no infill, I also reduced speed about 25%. This uses S3D supports.
It is now much better (not ideal, but better), indicating some kind of infill problem. Perhaps the s3D algorithm could be improved for this kind of situation. If there are suggestions to make it better without a new (and very slow) process, please post!
Using: Makergear-M2, V4 Hot end. Simplify 3.01