Hi everyone!!

I have just changed the stock bearings of my Sieg X2 mill for angular sealed ones. (7206-B-2RS). As I have disassembled the head of the mill, I need to align the spindle cast of the head with the cast that connects to the collumn.

So I've set-up the Rollie's Dad method for aligning the spindle with the collumn. I put the needle of the indicator right under the 14mm lenght rod, 12mm diameter, to first align the Y (spindle tilted away or closer to the collumn)

My mill and my measurements are in mms.

In the near Collet part of the measurument, I zeroed in the indicator the middle value, so I have the -0.02 -> 0 -> +0.02. (So the sum of both divided by two, to get the mean, is zero).

The positive values mean that the spindle runout is going closer to the collumn (pressing the needle) and the negative value means that the spindle is tilting away from the collumn). Am I right so far?

In the far end of the 12mm rod, I all positive values. I have 0 -> 0.045 -> 0.09, so the mean value is 0.045.

So taking both mean values, I have 0.045mm of tilting closer to the collumn (downwards as my setup is mounted parallel to the bench) in more or less 14mm of rod lenght.

So far my assumptions are right?

But now, how do I improve it? The desirable result to achieve would be to get for instance, the same -0.02 -> 0 -> +0.02 in the closer part of the collet and -0.045 -> 0 -> +0.045 in the far end? So both deviations are equal up and down? Is this what this adjust is about?

So I should shim between the two casts in order to "lift" the spindle a bit?

Thanks for reading and I'd appreciate any help in understanding this .. theory...

Regards, Rodrigo