For those who have a mill you know tramming can be a time consuming pain in the Ass. For minimll owners there is an ez solution called the EZ TRAM.
It comes with a Base and Shank piece that are precision ground flat and parallel to .0003” over entire surface
You place the base on the mill table and the mount the top to the spindle with a collet.
You then loosen the column and lower the head onto the base and tighten lightly.
You can slip a feeler guage or piece of paper between the head and base and lower head on top of it tightly. What you are looking for is equal tension by pulling the paper out. If one side slips and one side is tight you tap over the colum a hair until the paper is sandwiched equally tight all around the circumference.
Once that is done you tighten the colum and now the colum is perfectly square to the table.
The process takes only about 5 minutes.
It can be purchased from little machine shop and the accuracy and speed of set up is worth the cost.