Originally Posted by chktm
It seems like not only the pockets can vary but also the outside diameter of the Chinese bearings causing a similar thing. I try and find the most slop free and tightest fitting for the gyro. They are cheap as and when cleaned and lubed correctly last a long time and run a lot quieter.
As I mentioned earlier I enlisted some help from an aircraft engineer who very simply explained the problem with Chinese bearings
They are producing very big numbers at very competitive pricing so something has to suffer
Material is one but then tolerances are another and in the higher priced bearings that is what you are paying for .
If you are on good terms with a LHS and they have some stock it may be productive if you measured up the outer sizes and selected the better ones
If you have two sets of large allowed tolerances and the flywheel bore is at the max allowed and bearing the minimum that does not help
Bearing failure is hard to tie down but if the issue is pushed and replacement is offered the cost is considerably less than having to maintain closer tolerances .
I think the same applies to the CNC flywheels where I would say many people live with the noise unaware of the cause
Vibration is a bearing killer so the off balance advances bearings failure and it is presumed water ingress is blamed and so they are replaced non the wiser unless they read about it in a forum such as this