Hi All, I am now working on a Cincinnati Sabre 750, Model ERH and am starting disassembly for service of the X-Axis ballscrew. X-Axis started making a loud "scratchy" sound when using rapid or high feedrates. At slower rates, say, 30 IPM, the sound has a periodic characteristic which occurs apparently at 1 point of every ballscrew revolution. This leads me to suspect that the thrust and/or support bearings are failing.

Oddly, with the way covers off, it sounds as though the sound originates from the ballscrew nut - perhaps there is conducted vibration from the bearings to the nut?

I don't feel roughness when rotating the ballscrew by hand, though there is some drag - rotating the ballscrew via the bolt at the support bearing using an allen wrench, fingers on the short end of the wrench - rotates with some difficulty.

In disassembly, how are the taper pins in the thrust bearing housing and the ball nut removed? Each has a threaded hole - would I screw in a bolt to push it out, or would I use a slide hammer? Also, how to immobilize the ballscrew when removing the bolt in the ballscrew at the far end or support bearing - clamp the removed ballscrew in a vise (with padding of course)?

Thanks,

Drew