If you can make a way to flip your X axis frame so that the exposed ball screw mechanism will be at the back, it will save you tons of problems on the machine getting stuck or offset due to the dust debris from the wood, or the metal chips getting eaten by the ball screws and eventually will get stuck. as much as possible cover your ball screws from the direct exposure to saw dust or metal chips, if possible place your Y axis on top and the X axis flipped, I saw some commercial machines set-up this way, the guys that built those machines really knows how important it is to hide the ball screws from the dust debris, that makes their machines rock solid stable even on a thousand program loops