Looks pretty beefy.

Can't seem to see how the X axis is driven, would be nice if that was in the CAD. I'd also decoouple the X axis bearings from the gantry with an additional plate (I use the same setup you've drawn and adjusting the angle of the gantry and getting to the bearing blocks is a nightmare). Having another plate between the bearing blocks and the gantry extrusion will give you much more flexibility. Also be careful of how you attach the drive here; you want to be able to twist the gantry without forcing the ballnut to rotate too.

Oh and naming conventions seem a little off, just like mine is. Most CAD and CAM software treat X and Y as if you're looking at a graph. Decide where you want to stand when using the machine. Away and towards you should be Y. Left and right should be X. At the moment it sounds like you want to stand off to the side to use it. Eaiser to fix now then when it's built and all labelled up.