I have an OpenBuild 1510 belt-driven that I just assembled and tested after some initial electrical problems. My issue with the Z-axis is that there seems to be an inordinately small amount of travel between the bottom of the Z-axis and the work piece. For example, there is about 1/2" of the lead screw protruding from the bottom of the z-axis carriage that limits the movement of the router assembly. More importantly, at the z-axis highest point it trips the limit switch and there is barely enough room to put a bit into the router. That means that the router bit will not even clear the work when you proceed to the setup phase because the bottom of the z-axis carriage trips the limit switch again. Will switching the direction of movement solve that problem?