Design, Fabrication, and Qualification of a 3D Printed Metal Quadruped Body: Combination Hydraulic Manifold, Structure and Mechanical Interface

Additive manufacturing allows designers to make complex, efficient parts that are not achievable through conventional manufacturing techniques. Efficiencies are achieved by combining structural members, component interfaces, and hydraulic power distribution elements while eliminating redundant structural mass and volume. This paper documents the design, fabrication, inspection and testing of complex additively manufactured metal components. Parts utilizing AlSi10Mg aluminum alloy combine the roles of hydraulic manifold, mechanical interface, and core structure for a meso-scale quadruped robot. These parts allow Naval Research Laboratory (NRL) engineers to design and construct a highly capable quadruped robot that is both dynamic and lightweight. Metal parts were designed with computer aided design (CAD) and constructed using powder-bed direct laser metal sintering (DLMS). High-pressure hydraulic lines with internal fluid passageways were printed into the body assembly seamlessly creating a complex hydraulic manifold. After fabrication, a rigorous program involving post-processing, inspection, and destructive and non-destructive testing was performed to validate the design and manufacturing methods. The manifold has been approved for use and integrated on the quadruped, awaiting system level testing.