View Full Version : Square up mill head

11-09-2006, 06:49 AM
Here is how I square up a mill head after it has been tilted. I have done it this way for 35 years. It should only take 5 or 10 minutes to square up a mill with a little practice.

Last night the head was in this position milling a 25 degree angle. Squaring front to back (as shown) is slightly more difficult than square left to right. Squaring left to right is easier because the pivot has the same center as the spindle. As you can see squaring front to back the pivot and spindle do not have the same center.

Keep in mind squaring the head front to back is similar to using a level becuase both indicator readings with change in the same direction. The rear indicator reading changes at a smaller rate becuase it is closer to the pivot point. Sorry, the indicator face got washed out with to much light.

There was a .005" difference from the front to back. Adjust the head and then recheck with the indicator. If the condition worsened, you went the wrong direction. If the idicator runs out of travel or lifts off the table simply readjust the with the knee or the indicator itself.

Tighten the bolts equally and evenly and recheck for any changes in squareness.

Checking the right position. Less than a .0005" difference left to right and that is good enough for me.

Again, adjusting left to right is easy. When adjusting, split the total error in half and recheck. Continue untill you are satisfied. Don't be concerned over the indicator jumping across the "T-slots" as long as the spindle is rotated the same direction for each check. Rocking the spindle back and forth across a "t-slot" will result in eractic indicator readings.

Hope this is of interest,