Design help etc required with DIY CNC Router Design / Build

[Jonathan]

on the short axis with supported rails not too sure here - as there are torque and vertical loads from the z-axis carriage and router to account for - the top bearing carries vertical and torque and the bottom bearing carries the torque loading only

You can resolve the forces and moments on the bearings, I did it here:

http://www.mycncuk.com/forums/showth...inear-bearings-...

But it doesn't really achieve much except for deriving the obvious (space the bearings out as far as you can afford to, and minimise overhang) and showing what I said in my previous post.

I got the order changed

Excellent - what did you change it to?