Drill-press Table Squaring, High Precision

[Paul Alciatore]

The way a machinist trams a table like that is with a dial indicator on an L shaped arm. It is swept around in a circle, like your probe. That will get you down to 1/1000" or even less.

But before going to that much trouble, you may want to check out just how flat your table is. You may be chasing hills and valleys. Most drill press tables have a milled top surface. That is only the roughest finish in metal work. I have a milling machine with a ground table top and it still has hills and valleys of about 0.001" or more. Yes, it is a Chinese import. In situations like that brake rotors are often used on top of the table to average out those peaks. New brake rotors are very flat and the two faces are very parallel.

And before doing that it is a good idea to stone the table to remove any raised edges at any marks that may be present. Just a few strokes with a flat stone will do. Don't over do it.