I'm getting strange results with small cylindrical parts. I've posted details to the Lulzbot Taz forums which can be read here: https://forum.lulzbot.com/viewtopic.php?f=36&t=2949
"I'm testing the limitations of small part printing and have a weird issue. My extruder begins to drag through layers. It seems like the outside perimeter is extruding too much, building up, and causing the drag. I can print larger parts with no issue - so I don't think it's hardware... I'm using a 0.5mm and have tried 0.18 and 0.25 layer heights (both with 0.6mm width) - no difference. I'm using S3D for slicing and have tried 0% infill (just perimeter) and 100% infill, but S3D doesn't perform the infill lines - it skips them."
Attached is the STL if anyone is interested in trying to reproduce.