Thanks for your reply Doddy. Any machine I buy would be for hobby use in brass, steel and occasionally, aluminium. The largest envelope (if that is the right word) that I can see at the moment is 9"in X 9"in X 3"in and that is an aluminium job that would be difficult on my present manual machines.
I am learning to use Fusion 360 for modelling and have just started to have a look at the CAM features.
I have no background in cnc work having been a Quality Engineer/Quality Manager in the aerospace industry for most of my working life.
Brian