A new hope: Epoxy granite and steel.

[hardenum]

These are AC Servo's not DC steppers so inductance doesn't play such a large part in the performance as your using mains AC voltages so pushing volts/current through them isn't a problem, it's the rotor inertia you are more concerned with when it comes to Servo's.

Duly noted.

That sounds like a heavy build!
But you are missing some crucial informations: what would be the working area and what do you plan to make with it??

Target build volume 320(Y)640(X)180(Z). Primarily aluminium(AW-6060 / AW-6082 / AW-2007/ AW-1050A/ AW-5754/ AW-5083/ AW-7075), occasionally mild steel. Mostly sheet metal, sometimes a mold for silicone injection(low pressure).

Check out CTB servo in China. They make nice spindle servos, but they are quite bulky.

Thanks for the tip, I found one that I like. https://ctbservo.com/product/servo-s...75x175x360-mm/

I'm really not an EE guy, despite many attempts. What's the deal with Rated Speed and Max Speed.

Does this mean I can run any servo over it's Rated Speed or are "spindle motors" a different motor type that allows it?
ie. synchronous for positioning, asynchronous for spindle? Or can I take a eg. an oversized servo and use it to drive the spindle cartridge?