Mill Table Tram Measurement

[Skypilot]

Greetings,

I have a South Bend Mill that I just finished tramming. The X-Axis had a deviation of .002" but the Y-Axis is off by .012" with the front being lower. How can I shim up the front to get it more level? Thanks in advance for your help.

 

[Uglydog]

I don't know how the South Bends are designed.
However, by moving the ram forward and back on my Cincinnati I can get a different reading.
Also, consider where you want to do most of your work relative to the column.

Daryl
MN

 

[Bob Korves]

First, did you tram with all axes locked? If not, try again. It is also a good idea to adjust all the gibs and retest before making any changes. If the droop continues, it is probably due to wear in the knee ways and the carriage, not in the head mounting. Shimming the head is a quick and dirty solution, but only addresses the symptoms, not the problems. If you shim the head so it matches the table, and the table is drooping because of knee or table problems, they you will end up with the Z axis of the spindle and the Z axis of the knee parallel to each other, but at an angle to the Z (and probably Y) slide ways. Simply put, when you raise the knee, it will also move sideways relative to the spindle. A quick fix on one axis can negatively effect other axes. Just a heads up to pay attention to how you approach any adjustment or repair, and consider how it will affect the geometry of the rest of the machine...

 

[4GSR]

From what I can remember, the South Bend mill, the head would only tilt right to left, it would not nod in or out. Not sure if a optional accessory was available to allow this or not on the mill. Also, the mill had a round ram. I'm sure there is wear on the knee where it attaches to the column and likewise on the saddle. The table probably has some amount of wear to the saddle, too. Check the gib on the knee where it attaches to the column, maybe enough slop causing the in-accuracy seen. Tighten the gib a little and see if that makes a difference! Don't tighten it too tight, may never get it loose again! Ken