Spindle with ball bearing

[MEguy]

Does anyone know how to figure out the concentricity of a ball bearing Spindle when it spins at high rpm?? I know cap gauge is a good approach ....... but you guys might have an better idea. Thanks.

 

[janderson2]

Some of the disc drive houses require balancing.
There is a specific machine that does this, can't recall the name, but it's German and very tempermental