Chaz - I expect you've fixed the "servo error" issue by now, but I've also been setting up a 3-axis mill system for a mate (project on hold pending him getting some mechanical bits sorted) and had all the SZGH kit configured on his coffee table for testing. I found exactly the same problem until all three servos were connected. I was a bit worried when I tried with just one and kept getting errors... Seems like a nice bit of kit, though.

Looking forward to seeing this lathe project progress - good luck!