I am cleaning up and retrofitting an older Pratt & Whitney CNC tap/drill machine.
They used THK HSR 25A recirculating ball linear bearings for X, Y & Z. X and Y feel smooth. The Z bearings feel a bit rough and "tight", even after cleaning. They don't bind, but just don't feel nearly as smooth as X and Y. Is this a problem?
Some questions that come to mind:
- Is it normal for linear bearings to not feel perfectly smooth, perhaps being OK if they feel a bit tight to the untrained newbie?
- With the large load from the massive 5HP spindle motor and spindle assembly, have these bearings worn out and require replacing? Should I just put it back together and see how it works and address this if they heat up or make noise?
- Is ball replacement a possible fix (easy boys...)? Or is it a waste of time without regrinding the rails and/or bearing carriers?
Thanks in advance for any advice you can lend.
Scott
They used THK HSR 25A recirculating ball linear bearings for X, Y & Z. X and Y feel smooth. The Z bearings feel a bit rough and "tight", even after cleaning. They don't bind, but just don't feel nearly as smooth as X and Y. Is this a problem?
Some questions that come to mind:
- Is it normal for linear bearings to not feel perfectly smooth, perhaps being OK if they feel a bit tight to the untrained newbie?
- With the large load from the massive 5HP spindle motor and spindle assembly, have these bearings worn out and require replacing? Should I just put it back together and see how it works and address this if they heat up or make noise?
- Is ball replacement a possible fix (easy boys...)? Or is it a waste of time without regrinding the rails and/or bearing carriers?
Thanks in advance for any advice you can lend.
Scott