Selective laser melting of a 1U cubesat structure. Design for additive manufacturing and assembly

The aerospace industry has used Additive Manufacturing (AM) since its beginnings in the ‘80s. But in the last decade, new advancements in these technologies have led applications to proliferate moving from the prototyping to the direct part manufacturing, rapid tooling, and repairing. AM is a completely new manufacturing process if compared to the conventional subtracting methods. This technology has deeply influenced product design and assembly in the aerospace sector, becoming a strategic technology throughout the entire supply chain. AM enables easy integration of design change. It has the capability to build virtually any shape, and at least as importantly it allows complex features integration and part count reduction, greatly simplifying the product final assembly. These advantages can be addressed to the production of small satellites constellations, made by up to some hundreds of satellites, finding an optimum compromise between customization and modularization needs. The present work shows a re-design of the structural sub-system of a CubeSat from the nanosatellite class. Specifically, a 1U CubeSat design has been developed taking into account the consolidation of parts, integrating the features into more complex elements, reducing and/or avoiding the assembly issues, ignoring the constraints imposed by conventional processes while considering AM built related factors. A new 1U CubeSat composed of two already-assembled parts has been fabricated by the Selective Laser Melting (SLM) technology. Particular care has been taken for new features, e.g. the clearance and the shape of the hinge and the snap joint matching SLM specific constraints such as support structures design and removal planning, part orientation in the building platform, and hollowing out for powder removal. The obtained results point out AM as a key technology allowing for a drastic reduction of the part count for a complex mechanical system, as a small satellite structure is. Nevertheless, the technology built related factors must be taken into account in a Design for Additive Manufacturing (DFAM) approach. This paper shows the importance and the effectiveness of considering them in the designing phase.