Today I stripped down the table of my mini mill, because the y-axis has always been particularly sloppy ever since I got it. And I figure I should start with a clean, dialed-in machine. After cleaning chips and wiping down the machine I took off the x-axis by spinning the table all the way to the right and then taking off the handle and key. By jamming the table left to right a few times I was able to free the outer bearing and remove the table. The last bearing I took off by placing a crescent wrench against the bearing and then tapping it with a rubber mallet. Now the Y axis is exposed and the culprit became immediately apparent: the nut on the leadscrew is free floating in a slot in the y-axis table and is supposed to be pinned in place by a screw which was loose. Screwing it down and tightening the handle, the slop was instantly gone. Great, but I proceeded to finish stripping it down to clean and oil. Once the table was off I discovered the column was not properly aligned:
I loosened the outer two bolts and took a half-turn off of the center bolt and was able to rotate the column to visual alignment - once I have the table rebuilt I'll use an indicator on a magnetic base to confirm proper alignment.
I cleaned off all of the packing grease I could find and rubbed everything down with an oily cloth and reassembled the y-axis. I tightened the screw which pins the leadscrew nut and tightened the nut on the handle to a comfortable tension and there was no visible play in the bed - of course once fully assembled I'll verify with an indicator.
Tomorrow night I'll assemble the x-axis and work on confirming things are nice, smooth and aligned.
