As I continue to build my machine I often find myself looking through keling's website dreaming about the next cool thing I need to buy for my CNC.

Recently I have noticed that Keling sells some really neat, water cooled spindles and VFD's to control them....(very cool)...but I have also noticed an item they call a "Milling Machine Spindle". The outer case looks just like one of the larger stepper motors, but it appears to be used in place of the spindle/vfd combo. I did see that the spindle requires it's own driver, must be similar to a VFD????

So what is the difference? Why would you choose one over the other?