When going on a milling machine for the first time, its always good practice to check the position of the
machines head. The head can be adjusted in a angular fashion both forward and back from the user and
from the left and right. Therefor the cutting tool may not be perpendicular to the part when you first get on
the machine.

To indicate the machine, a dial test indicator is generally used along with a Indi-Col holder to hold the
indicator as its being indicated. Just as indicating the vice the indicator is attached to the spindle, however
in this case the spindle is not locked as you need to rotate the indicator to hit the 4 points created by the
way the head can be adjusted.

When indicating, some use a ground plate instead of the milling machine table, some use a large bearing
race, while others take a honing stone to check the table for burrs and indicate directly off the table. What
ever the method there are probably more different methods then I can write here. Myself I use the honing
stone check and indicate the table to eliminate the possibility of compounding errors of other methods.


As you can see the indicator holder (Indi-Col) holds the indicator on the smaller part of the spindle while
allowing you adjustment to indicate the table. Although the bolt loosening and tightening method to get
the head to align seems to take a while when you first do it, over time the method becomes easier to do.

Indicating the head doesn't take a long time compared to the time it will take to rework or completely
remake the work that was scrapped because the head was a couple of degrees off and you didn't see it.

Dimitrios Simitas