On 2013-04-09, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
fired this volley in :

1.5kw? as in 2 hp? Seems excessive for drilling .020 inch diameter
holes in pcb's. Milling .001 inch copper sheet isn't a major job
either.
Maybe 1/4 hp would be adequate, surely 1/2 hp?


It would be, but with 2HP, I can also do high-speed milling of tougher
materials, and the difference in cost between a 0.5KW spindle and a 1.5KW
version is about $30.

I have not seen one in the 30Krpm range... most metal bearings get weak
in the knees at those speeds, and most inverter drives top out at 400Hz,
which is the rated input for these at 24Krpm.

What I heard about those spindles is that they are junk. But they may
be cheap enough to just try out.

i