Hi,

I'm wondering why most non gantry mills are using spindle cartridge type with either gear/belt instead of running self-contained spindle. I mostly see self-contained spindle being used in router mill.

I understand traditional milling requires lower RPM but what about high speed machining? Can I strap a high speed self contained spindle (20-40k RPM) to my mill and do HSM?

Why isn't this done often?