Earl Sigurd
Aluminum
- Joined
- Jun 6, 2013
- Location
- N59 W3 UK
I have a CVA lathe in the UK, same as a EE but with a gearbox drive and styling like a 60's housing scheme.
I have looked through the references to bearings on this site and have seen 15 angle for 10EE bearings.
The various mfs cats list bearing stiffness for different contact angles. However to summarise:
1) The max rotational speed for any is many times that needed, slightly lower for 25 degree a/c.
2) The radial stiffness of 15 degree is only slightly lower than 25, however:
3) The axial stiffness for 25 is usually at least twice that for 15.
4) The stiffness for all is increased with preload, at the expense of bearing life and max speed, still way above lathe speed.
So it would seem that a heavy preload and 25 degree a/c would be best, any comments?
As an aside, I used to have use of a UK made Bridgeport made by Adcock and Shipley in the UK, which had an extra heavy preload on the spindle bearings. There was a plate on the head saying " Run spindle every day". Could this have been to prevent brinelling of the races? Should we make sure to rotate all preloaded bearings on regular basis?
Many have bought machines that have been unused for years/decades. Does this knacker preloaded bearings?
I have looked through the references to bearings on this site and have seen 15 angle for 10EE bearings.
The various mfs cats list bearing stiffness for different contact angles. However to summarise:
1) The max rotational speed for any is many times that needed, slightly lower for 25 degree a/c.
2) The radial stiffness of 15 degree is only slightly lower than 25, however:
3) The axial stiffness for 25 is usually at least twice that for 15.
4) The stiffness for all is increased with preload, at the expense of bearing life and max speed, still way above lathe speed.
So it would seem that a heavy preload and 25 degree a/c would be best, any comments?
As an aside, I used to have use of a UK made Bridgeport made by Adcock and Shipley in the UK, which had an extra heavy preload on the spindle bearings. There was a plate on the head saying " Run spindle every day". Could this have been to prevent brinelling of the races? Should we make sure to rotate all preloaded bearings on regular basis?
Many have bought machines that have been unused for years/decades. Does this knacker preloaded bearings?