My Brother CS6000i manual does not mention oiling at all, except to say one should not get oil on some specific part. A solution in this forum only refers to having to take the plastic covers off before oiling. So... is this machine supposed to be oil-free? If not, is there a guide with specific places to oil on it (after removing the plastic outer cases)? Thanks in advance.

Sewing Machines - Brother - CS6000i Computerized Sewing Machine