Initial Design Check Please

[JAZZCNC]

I went with the supported rails due to profile ones being out of my budget

Well if you haven't bought them already this is worth re-thinking. Profiled linear rails from china are now quite cheap and the difference isn't worth not using them.

yes they are 1605

Well this again is worth reconsidering. 5mm pitch is fine for harder materials like aluminium but does restrict the speed for cutting woods and plastics correctly. 10mm is a better balance and while more biased towards softer materials it's still gives more than capable resolution for aluminium.
If you connect to the screws with timing belts, which I suggest you do for resonance reasons, then it's an easy ratio change to increase resolution if you ever find your mostly cutting harder materials which need torque and resolution.

i went with that profile as it lined up nicely with the holes in the supported rail, making it easy to join the two.

Ok ye thought that may be case but layed flat like that weakens the material unless it's well supported from below which could be ok for the base if supported from below but the Gantry has is designed can't be so positioned like that so it will be weak in one direction. I'd think about using square rather than rectangle and beef it up a little, say 80x80 or 90x90, or go with "L" sahpe setup like I've posted on forum many times which is stiff in both directions.

With regards to mounting the bearing blocks to the gantry sides, do you mean by bolting a plate to the bottom of the gantry side and then the bearings to that, forming like an upside down T shape?

Something like this I knocked up to show both screws and gantry but with a little more bracing etc. There's many ways but sat on the bearings is strongest and easier to do.

Ok i will make the plate 20mm and remove the rear plate on the gantry. I saw the idea originally on the Sweetdream CNC which did seem like a good idea.

Argh but he's only used to taking Pics of UFO's and knows nothing about CNC.! . . Lol . . ( He's a mate not being rude.!!)