when you tram the machine. ideally your looking for your mill table to be flat first. once its flat. then you want to adjust the column to the table. this is usually done with shims between the column and the base where it attaches. i would not assume that the column and base are perpendicular to start with, as all floors have unevenness and you may have to adjust your shimming to get them within acceptable parameters. i have my ih column trammed to within .0002 while sweeping a 14" circle on the table. next you want to check that the quill is perpendicular in its travels to the table. and this is adjusted by shimming underneath the head, between the head mounting plate and the head.