you do not need external motion controllers/cards etc to run full size machines...
I have VMC with 15kW spindle and 2,5kW DC brush servos in X and Y, Z axis I have 5Kw servomotor but drives I use are only able deliver about 4kW power.
For now all of these are running from paraller port and Koyo DL06 PLC.
This setup I have been running 4433 hours ( just checked from maintenans hours) with better reliability than many new cheap commercial machine!
To run these big servos you need commercial drives, not hobby size or quality,
OK Gecko is industrial quality but small power use only...
big or small depeds who you ask, in some commercial applications less than 10 kW per axis is small =)
I use Copley Controls drive "Xenus XTL" witch can be used to drive AC or DC brushless or brush motors..
http://www.copleycontrols.com/Motion/Products/Drives/Digital/index.htmlThese drives accept directly step/dir or analog commands and accept 110/220V AC power as power supply... no need capacitors etc..
One neat feature is double encoder loop whera you can use encoder signal from motor for tight PID loop and secondary encoder signal from linear scale for accurate position loop....
ok these are lot more expensive... about 800 euros each, but... THE POWER!! =)
Regards Mika