Cartesian XYZ machines with frames made of extruded aluminum, T-Slot, Makerslide, and more. See http://reprap.org/wiki/Category:Aluminum. Previously named "Extruded Aluminum"
What pattern did you use for the MDF print deck? I am building the Wilson Ii which is an i3 mk3 clone but I cant find the drawing for the print deck
Could you link me to the drawing you used?