Been re-working the gantry a touch...

Its now a 40x200mm ITM profile vs the 160mm before... in addition to that, I reasoned that given that I was having to put 20mm spacers on the carriages to bring them in line with the ballscrew block, I may as well put that material into the gantry strength instead and raise the rails themselves out by 20mm... to that end I've designed a 20mm thick plate that will be mounted to the profile, then the rails will attach to the plate... the centre will be machined out to accommodate the motor mount and ballscrew bearing block.

The back is 12mm plate, and the top and bottom covers I figure may as well be made structural, so they are now mostly comprised of 4mm plate and will be screwed into the profile top/bottom, which I figure should help a little to reduce any deflection from forces in the Y-Axis.

Should be fairly strong?