Thanks for all your opinions,
I haven't replied sooner as I've been busy most evenings doing some prices for jobs and reading a book I picked up on the subject. As to the use of wood, it seems that the consensus is not to go near it and I guess it is obviously not as strong as metal but can a new one be bought or built by someone else as you suggested for my budget of £4000( electronics, and all necessary software incl.)

Anyone up for the project, 8x4 three axis with a short Z axis, London based would be better. In the meantime I've got to book myself in to a CAD course.

Garvan