Chinese 300W DC spindle - is the spindle shaft grounded?

[m_c]

A steel ball bearing isn't guaranteed to conduct, as even a thin layer of grease will act as an insulator

[HankMcSpank]

As an aside, does anyone know (or can check) if a typical chinese water cooled 800W spindle, has electrical continuity from its outer metal casing to its shaft?

[Kn8]

Hi I have just checked my 800W water cooled spindle for continuity between the outer case & the shaft rotating the shaft by hand the resistance measured varies between 2 & 7 ohms

[HankMcSpank]

If anyone else has a spare 300W spindle & associated mount (perhaps you've upgraded to water cooled spindle etc), then please shoot me a PM cos I need one more :-)

[fifa]

Spinle can be easy grounded also during operation. Add the axial brush in the top...

kr