I followed the link to CNCzone and read a little about the machine. It is built almost identical to the one that I built for myself. Mine can cut 30"X33" and is 4-axis. One problem that stands out, and is the same as my machine and that is that the ball screws are not protected from dust and debris. So far I've had no problems but a few years ago when Jim, MC2, who knows CNC better than most know the palms of their hand, was in town. He stopped by and looked the machine over and quickly acted shocked to see that the screws and rails had no protection. I got the impression that he considered it imperative to protect these components from dust.
I built mine from surplus aluminum and mostly used industrial components that I purchased on e-bay. I built the controller using compuserve drivers and am using a 75 volt, 7.5 amp power supply. Since building the machine around 2002 or 2003 I've only had 2 problems. One driver went bad so I replaced with a Geko driver and i had one thrust bearing pre-loaded to tightly and I had to replace.
Dick