Hi all,

Im looking at building a 1250mm x 1250mm x 300mm (cutting capacity) cnc router / miller from scratch. Will be cutting the usual MDF, ply and occasionally aluminium.

ive read through millions of posts on the forum (very useful!) but I still have a few questions before I get started on the CAD model.

as the x axis will be fairly long I am undecided whether to have 2 ball screws or one and this leads on to the next question 1 stepper motor or two. I think the two ball screws will be beneficial but if I use two steppers is it easy to get them in sync (via a slave) or would it be better to power the ball screws via 1 motor all linked by belt drive or should I just go for the 1 balls crew in the centre and power off 1 motor?

next question is the controller. As times are moving on is it best to go with USB connection or parallel, again pros and cons for both with the parallel port being tried and tested and most popular or to go with USB as it will probably go down that route in the future and I will be able to connect my laptop to it.
i don't mind going parallel and mach3 but would be good to connect via laptop.

also generally what size aluminium extrusion do people typically use, would 80 x 40 be too lightweight for the size of the router?

Is there much difference in accuracy and life span between flat supported rails and round supported rails and are the ones sold on eBay from honk kong etc ok or is it best to go with UK suppliers?

finally, may need a few parts machined and more advice so any help would be appreciated.

Will get some images up of the concept model one these few queries have been answered so feel free to give your input.

cheers,

Dan