We have been prototyping several different versions of quad-rotor frames build using rapid prototyping machines. We have built and tested a range of different designs using different materials. We are trying to optimize the durability and stiffness of the frame, while also keeping the weight low and the ease of assembly and manufacturing as simple as possible. The mechanical structure by folding allows for very high strength and mechanical simplicity due to small numbers of moving parts and three dimensional structures. We are trying to integrate the circuit board and sensors and wires into the same 2-dimensional production process before the frame is folded. The goal is to produce all of the functionally important aspects of a robot in one process allowing for quick and accurate customization and design while allowing for very easy production and assembly.
This is the prototype frame illustrating the new two-layer composite assembly.
These are our earlier attempts at making folded quadrotors, without rigid elements. The picture on the right shows a quad design (without control electronics) that was later sucessfully flown. The frame itself weighs only about 4 grams. The picture on the right is the two dimensional design file of this quad before folding (red represents through-cuts and blue represents perforation lines to facilitate folding).