Router Build number 2

[JAZZCNC]

How over built are we talking? the ability to take a full sheet of ply is worth something. If it wasn't the space restrictions I have I would be building a 8x4 machine in which case I guess I would be building the stronger gantry anyway.

Charlie You said cutting Aluminium to high surface finish, ply is different thing altogether. Your first design will quite happily cut ply but aluminium is different matter. The Stiffness required goes up quite lot and to have high quality surface finish it goes to another level. Anything you can do to lessen resonance will help with surface finish so long hollow flexi beams are best avoided.
This means using thick walled heavily braced and stiffened design which opens up complete new set of issues regards ballscrews,servo, controllers etc which get expensive quickly.

If your spaced limited look at building vertical. You'll get 8x4 in the same space as your First machine. Something along the longs lines of this which I'm building at minute thou for high end aluminium I'd change the design slightly and do away with gantry sides.