Well here we go again, start another build

[routercnc]

Hi D-Man,

I assume at that size you are looking to cut wood, not metal?

I also guess this is an initial layout to see how it might work because there is clearly a lot to add. The bed I assume would also be aluminium box sections running between the 2 end plates? Even for wood you need a reasonable support to reduce vibration.

The raised legs and gantry sides dropped down look like you are considering a cross beam underneath for a single X drive in the centre? If this is the case then at this span it is not advised due to racking problems. 600mm width is considered the general switching point from single to twin.

If you are going twin X then I would extend the end plates to have additional material to allow you to mount steppers, bearing blocks etc. You can either go further out and run the ballscrews down the outside, or go up and run the ballscrews directly above the supported X rails (clearance hole required in gantry to clear ballscrew). Going above the rails is a bit stiffer and would be my preference (direct connection to gantry rather than bracket off the side), but would get more dust/swarf from cutting if no extraction used.

I think by 'Z axis' you also mean the 'Y' as that is not yet drawn also. Can you afford 1000mm profile rail for Y? Used sets go for £150-£200 on e-bay e.g. 'fa-system'. You can put the rails top and bottom and have a semi-wrap around Y axis leaving you to put the ballscrew on the top, or behind (although not favoured by some). This keeps the Y axis close to the gantry.

The standard Y/Z axis is usually a pair of 20mm plates, recessed to take bearing blocks, etc. The front plate can be tapped to take your spindle mount, and the rear plate then fixes to the Y bearings via small intermediate blocks bolted at either end perpendicular to the main plate.