I can't seem to get my slic3r settings right for 100 or even 150 microns. I use the same settings for 450 down to 200 microns and all my prints come out great. At 150 or 100 microns, my external perimeters look pretty good. However, my infill is piling up and then the nozzle is bumping over it layer after layer. I tried to play around with the advanced settings but I don't really know what I am doing there. I did try to increase the speed of infill but that didn't seem to help.