OK, so will whipping still be an issue with 2no. 1610 screws at 1500mm long - as they will still both sag? Jonathan have you drilled your housings with a holesaw? if so can you recommend a make, I bought some makita ones a while back and they are rubbish.

Also what are the implications when buying drivers if you are going to add another stepper into the mix later? (I was thinking of getting the electronics from http://www.diycnc.co.uk by the way)

I do want to be able to cut more than just ply! everything from aluminium/ply/mdf for furniture making to paper/card with a drag knife for architectural model making/graphics. not sure if I am being unrealistic as I am sure one machine can't properly fit all tasks?

Apologies for all the questions!

Joe