First time build - Steel Frame CNC Router

[examorph]

I made a few changes to the gantry sides as suggested:
Attachment 17174Attachment 17173Attachment 17175Attachment 17176Attachment 17177
Side plate is 10mm thick steel welded to gantry box section. Clearance between the frame and gantry sides is 10mm, so need to be sure that bolts which go into the ball nut bracket are only M5 so that the head doesn't stick out too far.

Images of X Axis carriage support plate also attached, thought it might be easier for access if I followed other designs on this forum and had bolts running into the side. If you think the 4 bolt square pattern on top face would be better, I could probably cut a slot in the gantry base 'L' to get access to them and have it that way instead?
If holes seem to close on the support plate, would it be worth going with the smaller width type carriages (without the flange) on the X also?

One thing I haven't really thought out yet for the frame is the bed. Will look back through some build logs and see how others have been doing it and get something up for comment soon.