Lol, thanks all, my fault that I didn't mention the frame supports are temporary, and are being used for construction at this stage only.

when I take it home to the workshop, I intend mounting one end of it to the unused end of my workbench which is welded steel frame and bolted to the wall and floor. I have to do this as space is stupidly tight which is why I'm not making a bigger CNC.

the front legs will be on the floor and can be braced and bolted down as needed.

Once I have a rough idea of the job, I like to design as I build, if it don't work then lesson learnt, change it, weld a bit on, cut a bit off and move on :)

as said, a carriage made on the lines of one of my carriages will work I think, will need an extra bearing or two but I think it will work.

am I correct in my assumptions that reduction gearing is a good idea on the stepper drives? I was working on 3:1 for each axis but I'm not 100% convinced yet. My motors are 3Nm 4.2A Nema 23's.

dave