Eventorbot! Open source 3D printer. Simple with less materials. Frame is made of a single 4′ long, 2 1/2″ square tube (16 gauge/1.5mm/.0598″ thick, cost: less then $20.00). With the design there is less plastic parts, stronger structure, all wires are hidden, and a more appealing/finish look. (…)
The unit is supposed to resemble a robotic arm with hydraulic tubes. It was designed for prints to be less affected by vibrations. With the 1 solid frame, any vibrations of any axis will cause the other axis to move with it. For example: If the X axis causes a slight vibration/1mm movement to the right, the Z and Y axis will also move that 1mm to the right. This will result in a better print as everything will remain squared.
The Thingiverse page (linked to above) has all the STLs you need to print your own, supplemented by the usual hardware — look for the parts list on RepRap.org.