Hi,
I have a General 25-100 10" swing midi lathe and its about 2 years old. I have just become aware that at about 3000 rpm and above the headstock bearings make an intermittent but sill rather coninuous popping chirp ( but not very high pitched ) racing sound. I have run the motor with out the belt and it is quiet, so its not the motor. When you rotate the headstock spindle by hand you can somewhat hear the bearings make noise but it is neither a rough or high pitched sound. It just sounds like the bearings are dry or something ( they are permanetly sealed bearings ). As I have more recently been using the lathe at higher speeds I do not know it this is an old or new problem. There doesnt seem to be any play in the spindle. Any suggestions if the bearings need to be replaced?