Hey xyzer, If your CNC has a lot of sensitive electronics then a rotary converter should do the trick, chose one that has advanced voltage regulation to protect computers and etc. Alternatively run the electronics off the 240 volt side of things by swapping out the transformer. I had a unit when I was in the UK made by a company called AmericanRotary, I bought it second hand for around £500 and it ran my spindle moulder and industrial band saw. It never let me down and when I emigrated to Australia I sold it for £500 so it cost me nothing. The only other piece of advice is that all this sort of equipment gets hot and has cooling vents, not ideal in a joinery shop full of fine dust particles. Either position it in a clean area or blow it out regularly with low pressure air.
Bob