"Tramming" or Aligning a
 Bridgeport Type Milling Head

        1) Place the machine spindle about an inch in from the back table edge.

        2) Using a bent rod, or an indicator holder like the  1st Word , set the indicator
            anywhere from 6" to 8" out from the spindle center.

        3) Use 1-2-3 blocks, or a similar gage block to slide under the indicator for the reading.

        4) Tighten the knee-lock clamp on the saddle.*

        5) Adjust the swivel head in the X-axis to get zero readings at 
            positions #1 and #2. ( at about 1" in from the table edge )
            This will roughly align the head in the X-axis.**

        6) Now swing the indicator to the #3 position, and adjust the knuckle joint
            in the Y-axis to get zero readings at positions #1 and #3. 

        7) At this point the head is aligned quite close. Now go back and check
            positions #1 and #2, and adjust if necessary. Then check #1 and #3 again
            and adjust if needed.

        8) When all (3) positions read zero, (or within a total of .001) the head is 
            aligned in both axes.

            Note:
            With the indicator at the #3 position, loosen the knee-lock clamp and check
            the indicator reading. If the reading drops .003 or more, it's time to snug up
            the gib on the knee ways.
            ( but it's always a good practice to tighten the knee-lock clamp when machining high
            accuracy cuts )

             Note:
            When adjusting the swivel and knuckle, leave a little tension on the clamping bolts.
            This will help prevent the head from moving when you fully tighten these bolts.