In 2003, I built a CNC router to allow me to accurately cut snowboard cores, bases, and mold parts. The cutting area is 2′ x 7’1″, with 5″ of travel in the Z axis (you end up with less due to the length of the cutter, though.) The frame is made of structural aluminum. Each axis moves on steel linear slides, and the plates that make up the mount for the Z axis are 3/4″ aluminum. There are 3 stepper motors powered and controlled by a controller in the grey box above the machine.
The controller receives the program, or manual commands, from a small dedicated computer on a shelf nearby. The machine is programmed with industry standard “G-codes." These are generated from either a commercial CAD/CAM system, or from my own snowboard-specific CAM system called MonkeyCAM.
I had originally hoped it might be suitable for cutting aluminum as well, but it’s really only good for wood and plastics, which is just fine since I primarily use it for snowboard construction and other random woodworking projects.