@JohnHaine, the larger Denford lathes used induction motors with a KEB VFD, not to be confused with a KB-Electronics DC drive.

The issue I had, was the motor wasn't rated at 50Hz (I want to say it was something seemingly random like 63Hz - I thought I still had a photo of it, but I can't find it).
A standard VFD will by default be set to provide the rated voltage at 50Hz, however I was never sure whether the motor on the cyclone should have that point set to the rated speed, or the standard 50Hz.