Quote Originally Posted by qwertyjon View Post
Can anyone point out any obvious faults before I carry on?
Yes I can point out a few things. The gantry is a little flimsy with just one piece of 90x90 but worse is the connection to the X axis bearings. Relying just on the bolts in profile won't be enough and it will need much more bracing than that other wise you'll get resonance and chatter at the cutter.
I would increase the plate thickness on the ballnut mounts and bearing plates.

Presume those Angle brackets are just for stiffening and your not relying on them to hold profile together, if you are they won't be good enough.

To be honest I would re-think the gantry single profile piece and beef it up a little.