Using the 40mm x 40mm aluminum extrusion I found in my studio, I was able to put together quite a solid frame for the printer using some brackets from the 80/20 eBay store. I went with metal brackets because I wanted a printer that was solid and reliable. I do not want to have to worry about a 3d printed part cracking while the machine is operating; plus they wont melt at the standard 3d printer temperatures.
For the z-axis I used Misumi 1515 extrusion I had in my parts bin. 2 beams on either side spaced 8 inches apart should provide enough support and guidance for the z axis.
A piece of 1/8″ hardboard makes up the middle platform between the print chamber and the storage cabinet on the bottom. The electronics will be mounted to the bottom of this hardboard in the final version.