High speed spindles on conventional mills?

[alanambrose]

Hi,

I saw recently clough42 put a router-style high-speed spindle on a conventional (but diy CNCed) mill, which surprised me.

I should probably understand the engineering dynamics involved but can someone enlighten me on the general physics envelope of high rigidity conventional mills with say speeds up to 2K rpm and heavy tooling compared to low-rigidity router-style with speeds to 25K rpm and small tooling.

Is 'router-style' a way of getting horsepower into the work with low rigidity or what? Why don't all mills have high speed spindles? etc etc etc.

TIA, Alan