Awesome Jgro!
And thanks - I might borrow your "outa - the - box" by being in the box for the Z axis!
I was just struggling on my design and your method may be my solution!
I like how you nested the bearings inside the rails! Helps keep your x-axis size by a bit. The rest of the rig is cool too! Nice sw image too.
Gud-on-ya-mate! (pronounce that "maight")

Jim!
mental note - lurking and doing -- not blabin' I'd better get back to the garage (that's pronounces gare-ig) and get some work done!