I just got a series 1 textron cnc, I yanked the electronics and now have it moving and running code. I ran a circular part and did a slow cleanup pass taking off .005 of material in a climbing direction at around 4ipm, material aluminum. Anyway, my little mill will give me a mirror finish when do this but my new series 1 chatters no matter what the speed of the spindle. Could this be the bearings in the quill and spindle? How would I check? FYI I have a kwik chuck, looks factory and I havn't figured out how to get it out.