Thanks for the reply Doddy - lots of food for thought.

Hope you don't mind if I follow up your replies with a couple of extra questions?

4. Could you pass some details of this solution - I have been looking at AndyUK's router build and considering copying what has been done there mainly due to the exceptional schematic he's put up - albeit with some down-speccing in a couple of areas, I don't think I'll be needing anywhere near the amps he's using, although if I'm going to be going 4th axis then I might need it all or close to it, I'll have to finalise my sums.

5. Did you use the existing bearings at the ends of the table for mounting your ball screws / did you upgrade the bearings to something like opposing taper bearings - the X2.7 might be better as it's a later machine but my X3 has quite horrible bearing races and was expecting to make new plates for mounting BK/BF12 mounts - still to do the CAD model for the XY table, been learning Fusion 360 with Lars... Having said that I could get the ball screw stepper end threaded by the supplier (Fred at BST perhaps) and thread the stepper shaft coupling to suit the end of the ball screw and adjust that way and use better bearings in the existing plates

6. Coming to the conclusion that you are spot on about this, time to jump in

Thanks again,

Geoff