Diy cnc milling machine 50mm facemill

Face milling on steel. Only 1 carbide insert on a facemill, so facemiling or fly cutting. ae 46mm ap 0.2mm, feed 100mm/min spindle speed 860rpm. After test i noticed that my ballnut of Z axis was loosed by it self. Ballnut has thread connection to Z carriage, it causes that surface quality that is visible at the end of video.
+