Following on from my query about this I picked up a cheap 5HP 3 phase
400-440v inverter. Wired it in to the "real" output of the Transwave transformer (ie single phase 415volt-ish). Looped the 3rd phase into this. Runs fine until I try to run the lathe at top speed, at which point it indicates an over current fault. The conclusion is that a 5HP inverter wired in this way isn't up to the job of a fully loaded 3HP motor in a CVA lathe - which is really what Rob said in the original post. A 7.5-10HP 3 phase 400-440 volt inverter should do the job - just need to find one cheaply.Charles