With the X-axis just about complete, I started work on the table and the cross piece that will connect the two X-axis linear bearings. I cut the 1/2" aluminum plate with my table saw and a nice carbide blade. It took about 6 passes with the blade slightly higher each time until the cut was complete. This worked extremely well, but my cut wasn't exactly square. I think a radial arm saw might produce a more square cut, but the table saw was all that I had, so it had to do. Next time I'll try cutting the plate with a carbide blade in my skill saw and a square rip fence clamped to the plate.
Here you can see the cross member which will connect the two X-axis LB's. This setup slides extremely well and is quite rigid.
Checking the base plate for flatness revealed a .010 dip near the center of the plate. One of the drawbacks of using the surplus plate from Blue Collar Supply is that the plates are sheared. This results in warping which is nearly impossible to correct. I looked through at least 25 plates before I found the flatest one that I could.
Another shot showing how the cross member is going to attach to the LB's.