Sautenich

Hi Everyone! We meet problem in our lab with printing quality with Ultimaker 3. Plastic PLA. We have already changed extruder, checked feed system, changed printing and feeding speed, but from time to time the problem comes back. Pls, look at the photos, maybe you have meet these problems before? What could you suggest in our case? What helped you with it? Thx in advance ;) Best, Sautenich