When marking through holes to locate drilling holes in the y and z angles, make sure you mark the outside, not the inside, or the measurements won't be right! Nearly got that all wrong.

I've been looking at http://www.reprap.org/bin/view/Main/McWire_Cartesian_Bot_1_2 to work out where to attach the y-rails to the x-stage, and two pictures show them in very different places. I have plumped for centring the rail across the stage to see if that works.

Here is a diagram of the y-rails:


I have also chosen where to put the fixed side bearings, or PTFE disks in my case, and will experiment with springs and the swinging brackets. I'll put up the x-stage diagram when it's decided.