Thanks Jazz. I will change the design to incorporate the twin screws with belts in my next drawing. I could change the motor to whatever you recommend though, it doesn't have to stay at a Nema 34?

The frame for the Z axis is just a starting point, the actual Z will mount to the box section but wont be relying solely on the box. It will be a solid construction all round and will cut every material possible. The main material I will be cutting will be 6082 aluminium so the stiffness will hopefully provide me with a great finish on the cutting surface, rather than the opportunity of mounting a monster spindle. i will stick to the 2.2Kw items most people use.

I know it may be overkill, but I think it will be great to have the best machine you can build and afford, rather than something you know you could have improved and done better on, that would just bug me.

If there are any other changes I need to make, please comment.

Thanks as always for the quick replies, really appreciate it!