Friday, May 31, 2013

Mill: Solid Column Upgrade

The tilting column's mechanism sucks. It's a pain adjusting with any precision since you need to use a big wrench and high torque. It's also hangs off the back of the table which greatly reduces it's rigidity. Finally, it can easily go out of X alignment without you knowing it. For those reasons I upgraded to the Little Machine Shop solid column:

It has a column with thicker walls than stock with bolts via four bolts to the bed. It's much superior. You have to use shims to adjust both X and Y alignment. You can view the two adjustment separately, and simply sum the shim on the shared corner. For example, if you need 0.001" of shims on the front of the column and 0.002" of shims on the right of the column, then the left back corner wouldn't have any shims, the left front corner would have a 0.001" shim, the left right corner would have a 0.002" shim, and the right front corner would have a 0.004" shim.

I upgraded the mounting bolts to grade 12.9 M8x40 socket head cap screws which are 5mm longer and have more thread engagement. I used a torque wrench to tighten the bolts to make my readings consistent between adjustments, using 16.5 ft/lbs (200 in/lbs) with silver anti-sieze on the threads.

 In the above picture you can just see the end of a foil shim sticking out between the base and column.


  1. Hi Zoltan. I have an older X2 mill and am considering this upgrade. Does this increase the Y travel? Thanks, Alan.