Quote Originally Posted by picclock View Post
The conventional method is to use deep groove ball races for the axial thrust at the ballscrew ends. This BK/BF system uses two races in which the outer part of the race is spaced apart and the inners compressed until they rotate with little axial movement. balls used in this way run on the edge of the grooves in the casing, which makes me unsettled. Using a thrust race for axial loads the ball is fully supported by the machined recess in the support washer, so a much larger area of contact is used.
The 'conventional' method should use angular contact bearings, not deep groove bearings, which are far more suited to the purpose than a standard thrust bearing.

A basic thrust bearing gives very little radial support, so unless they're housed and adjusted perfectly, when spun at any speed your shaft/ball screw will likely whip, resulting in the kind of issue you are attempting to avoid. Any play in an angular contact should be noticeable in backlash long before damage from whipping become an issue, unlike a basic thrust bearing.