Apparatus and methods are disclosed that are useful for robotic gantry systems that are lightweight while at the same time offering rigidity or stiffness for implementation in Contour Crafting construction and material delivery techniques. The present disclosure is directed to robotic gantry system and material transport apparatus that use of very light structural members that have sufficient compressive strength, but which may otherwise be weak in the presence of bending forces, in conjunction with cables that provide stiffness against bending. Use of such cables provides needed tension while at the same time allowing the robotic gantry system to be very light compared to solid structures, e.g., those with I-beams, etc. Material delivery systems including passive articulated arms are also disclosed.