After upgrading my KMG to direct drive, I was left with the prospect of having to purchase another VFD (the old motore/controller was a DC setup). My pal Steve Kelly shared with me how to wire two 3 phase motors into a single VFD.... saving me about $400 versus having to purchase a new VFD.
I've created a new webpage on my site about how I did it......
http://www.caffreyknives.net/1_VFD_2_Motors.html
I'm not an electrician, but am comfortable with electricity and wiring.....but I'm certainly no expert. All I know is that it worked for me, with the setup I used. If your setup is different then what I used, I doubt I'd be able to give you an pinpoint information, or answer specific questions.