I am brand new to the art of 3D Printing. Just received my new printer "SUNLU-FDM-S8" Using the cura slicer software that came with the unit. My first print job was a practice model provided with the software package. I used all the settings they described in the into setup guide. The final print you see pimples both inside and outside of the model. They are not air bubbles, so not sure what setting I would need to adjust. Help thoughts from the gurus out their in Forum Land?...