The table is going to be fixed but I have left room for sacrificial packing on the workspace to build it up if need be. The point about widening the bearing spacings was on my to do list and has now been done. The z axis question im not quite sure I understand what you mean. Here are a few more pics to show exactly how it is in its entirety. I have yet to put a lot of holes and strengthening brackets on but I can do that as I go along with the build. I will be moving onto building the z axis next week :)

Z AXIS DOWN

Z AXIS UP

Y Bearings and rails

Side View