Just wanted to thank Gunner for his excellant step by step essay on replacing spindle bearings on an old chucker I picked up.I have the bearings and about to install them but curious about some numbers I see on the spindle itself (8 and 3) next to the bearing location and the instructions from the bearing box sais to line up the #'s of maximum radial eccentricity of the bearings 180 degrees oppisate of the shaft and housing eccentricity. I am assuming these numbers on the spindle designate this although Gunner did not mention anything about the spindle or housing runnout.These numbers are in microns and I figure that translates to .000003 of an inch, the bearings are marked 2 and
3.Personally I have no concept of how this eccentricity is measured especially 50 years ago when this spindle was originally ground? This is the first time I have dealt with such precision bearings and would like to take my time and learn to do it right the first time. Thanks for any input on installing or how the hell someone measures to six decimal points. Jim