This is a short demo to show you an advanced 3d printing technique for printing lightweight strutures for an rc aeroplane. The same technique can be used for printing robotic parts that have to be lightweight to reduce costs for strong motors and the amount of plastic used for printing.
The magic is to reduce the printed part to only print its inner structure- no top, no bottom, no vertical shells. These parts are replaced by glueing lightweight materils on this 3d printed structure like Japanese paper oder thin plastic foil used in the kitchen. This can be sprayed or painted to stabilize the structure.