"Henge", 3 Axis Cnc, Fixed Gantry, Moving Table

[Greeny]

Hi,

I have previously had designs on building a cnc, but various stuff cropped up & diverted me, so they never got past the design stage.
I'm hoping to re-boot with a smaller, simpler design that i have been researching for quite a few months.

I am immediately breaking the rules as over the years I have collected various mechanical components and I have designed a machine around what I have “in stock”
I know is the wrong way to do it, but that's just the way it is with this one, cos i'm too tight to chuck owt away!

I want to build a Fixed Gantry, Moving Table Cnc. The working area will be constrained (by the parts i have) to 350 x 350mm x 200mm(Z).
Mainly for cutting Aluminium, but also wood & composites such as fibreglass.

Parts & Materials I already have :
6x 20mm Misumi linear rails 580mm long
3x 16mm, 5mm pitch NSK ballscrews with a travel of 350mm
6mtr 200 x 75 steel C-Section
The C-Section is parallel flange and is sturdy stuff (6mm thick with 12mm thick sides)which weighs in at about 23kg /mtr
I realise box section is better & stiffer, but i got 6 metres of this stuff super cheap ages ago & i'm sick of falling over it!

Here are some basic renders of the initial design done with my first steps in fusion 360 (which is a great program)
I have not gone into great detail in the cad as I don't think it's worth rendering every last detail, just the general outlines. The cad is excellent for finding interference parts & testing movement etc.

Construction of the frame will be tack welding, then lots of drilling & bolting, with brackets where needed. I only have basic hand tools & a drill press, and very little mechanical experience.
The orange plates are 10 or 12mm ground steel gauge plate & the white parts Aluminium tooling plate. The red indicates the cutting area.

The Ballscrews are 5mm pitch so I'm planning on ditching the motor mounts & using belts & pulleys to gear 1:2 on X&Y , at the moment I have Z at 1:1
Motors will probably be 3 or 4Nm Nema23 and AM882 drives
2.2kw Chinese water cooled spindle & VFD.

I'm planning to do Axis alignment on the Y plate using epoxy putty & location pins. Then bolting.

Any comments, criticism, suggestions or ideas gratefully accepted.
Cheers.