I have a old (1943) bridgeport M-head I have owned since 1985. It has worked OK until I had a boring head stuck and tried hitting the drawbar top with a brass mallet to get it out and then a wedge between spindle bottom and the boring head to remove it. Ever since it would get a harmonic chatter when boring that was not there before as well as leaving a rough finish when flycutting. I always had slop between the pulley splines and the spindle but it did not seem to cause issues with the surface finish. After reading thru these forums it seems when the spindle bearings are worn issues like I am having will occur. I purchased all 6 bearings for the spindle and pulley assembly as well as a NOS MT@ spindle with the drive splines/pulley top with those retaining nuts and funny lockrings. I took apart the spindle today and all 4 spindle bearings were common 5205/c3 bearings. The new spindle bearings I bought were a NSK matched set of 7205 ctynsul p4 abec7 for the spindle bottom and upper bearings of 6205 C3. The angular 7205 bearings have a sidways v scribed on the outer race which i am guessing is the shape of the races. I have the folowing questions.
1) which way do I install the bearings or does it not matter the bearings also have a radius on the edge of the outer race on one side if that means anything. Both bearings came as a set in one box.
2) the original spacers appear to there is the preload set by them? Is one supposed to be a different width from the other?
3) when assembling the bearings on the spindle the 7205 I will press on by the inner race so as to put no side pressure on the bearings.
4) installing the top nut will squeeze the races in place between the spacers (upper bearings also have a inner and outer spacer. Is there a torque value for it or just tighten real good till a locking prong will fit in one of the 4 slots?
1) which way do I install the bearings or does it not matter the bearings also have a radius on the edge of the outer race on one side if that means anything. Both bearings came as a set in one box.
2) the original spacers appear to there is the preload set by them? Is one supposed to be a different width from the other?
3) when assembling the bearings on the spindle the 7205 I will press on by the inner race so as to put no side pressure on the bearings.
4) installing the top nut will squeeze the races in place between the spacers (upper bearings also have a inner and outer spacer. Is there a torque value for it or just tighten real good till a locking prong will fit in one of the 4 slots?