I have started off by designing the base platform. The base platform uses heavy duty gauge 80mm aluminum extrusions. I particularly like this extrusion because their walls are 4mm thick, and they are fully supported to the center core, this adds a lot of strength to the extrusion. I am attaching a cross section of the extrusion.



I also designed the platform with the rails being supported by the extrusion (rails sitting on the extrusion), and to hanging to the side supported by screws. The platform footprint is about 60" x 60" with 2 beams along the y-axis and 3 beams across the x-axis which I believe is sufficient enough to mill aluminum plates between 1/2" - 1" for my needs.