Printed PaulSat

grabcad

This entry is based on a designer's extensive experience in creating CubeSat frames, including working on ESTCube-1, Estonia's first satellite still in orbit. They also designed their company's CubeSat structure product line. Their practical experience assembling real CubeSats and conducting space qualification tests provides valuable know-how. The designer notes that many other CubeSat structure designs have been inspired by the Pumpkin CubeSat Kit, but more elegant and mass-efficient alternatives are possible. The proposed design removes stack beams and standoffs between subsystems, instead using on-demand 3D printing to manufacture corner slots with minimal margins to hold PCBs in place. A solar panel will securely fasten the PCBs to prevent them from sliding out. A detailed description of the design is available under files. Key benefits of this design include a single-part structure, Helicoil reinforced solar panel mounting holes for easy attachment and removal of side panels, compatibility with current manufacturing technologies, a low mass (54 grams for a 1U aluminum structure), use of non-problematic materials (aluminium), ease of modification, integrated deployment switch and separation spring, scalability up to 12U depending on the configuration, conformity to CubeSat Specification and launcher requirements. To create this structure, designers should model the CubeSat using 3D modelling software, connect subsystems with common PC104 connectors or a separate back-plate motherboard, modify distances between corner slots as needed, send the model to on-demand additive manufacturing, assemble PCB stacks outside the frame, attach solar panels and antennas using screws or compliant mechanisms, insert the PCB stack into the frame from a designated side, connect cables during insertion, and finally attach the last remaining solar panel. Aluminium AlSi10Mg with Direct Metal Laser Sintering (DMLS) is chosen for its advantages in radiation protection and self-supporting nature of DMLS build chambers. Despite limitations on print size due to common 3D printers, new EOS M400 printers can accommodate up to 27U CubeSats. Aluminium meets all environmental requirements, thermal and outgassing standards, as well as CubeSat and dispenser requirements. Future improvements may include compliant mechanism solar panels, which would require the ability to print different materials with DMLS/SLS. The deployment switch and separation spring could also be attached during printing by pausing the process and resuming later. Stack 3D models are from GomSpace and CubeSpace.