I have a CNC3040 from eBay and it works great. It has got me on the learning curve and given the confidence to try to make my own machine now :)

So I have a few questions if I may:


1) What are the pros and cons of ball-screw vs. lead-screw?

2) How important is supported rail vs. unsupported? I plan to build a machine that will have a 120cm x 60cm cutting area.

3) What factors dictate the max. speed of a machine? Is it the motors or the drivers, and how can I estimate the speed I'll get?

Thanks!