SLS Parts Give Student Competitors an Edge

There’s little doubt student design competitions are a training ground for next-generation engineers. Tasked with highly complex tasks, the student teams bring their innovation chops and the latest design tools to bear on problem-solving, taking their learned experiences to industry and paving the way for the mainstreaming of technologies like 3D printing.

A student team at the University of Applied Sciences Northwestern Switzerland FHNW is no exception. The team of nine Bachelor students from three fields of study worked for a year building a model Mars rover and optimizing key parts for 3D printing. Their reward: Placing 6^th in the European Rover Challenge (ERC) out of 19 teams hailing from all over Europe and being the only newcomer ranked in the top 10.

The ERC is an international robotics competition where academic teams from around the world present their mobile robot designs and compete against other teams based on real European Space Agency (ESA) and NASA missions. The competition takes place on an artificial Martian track, directly derived from the surface of Red Planet. For this year’s competition, the newly-formed FHNW team focused specifically on the drivetrain and manipulator functions (robotic arm and gripper) as those components were essential to completing the four tasks specified by the competition. The tasks included navigation, probing, maintenance, and science.

The team opted for additive manufacturing because of the complexity of the parts and the wide range of available materials that could be used, according to Nadine Richard, a fifth semester mechanical engineering student in charge of the gripper on the project. The team opted to use the Fused Deposition Modeling (FDM) printers available at the university to produce the tires, to make them as hollow as possible, as well as for the mast used to mount cameras and antennas.

Because of the high-level requirements of the gripper, the team wanted a 3D printing technology that was more robust. Specifically, the gripper needed to be highly durable, able to withstand forces from all directions, as well as extremely light because of the location of its center of gravity.  The team opted to use selective laser sintering (SLS) technology from Sintratec. The main advantages of the SLS technology were the lack of support structures, incredible accuracy, and robustness, Richard says. The team printed the parts using PA12 materials on the Sintratec S2 printer.

“With SLS prototypes you can really test the functions of the part,” she explains. “The laser sintered parts are not just for prototyping, but can be tested and used in their function without any restrictions.”

Sintratec was a natural partner as their close proximity enabled the team to get design advice as well as pick up the parts themselves from the company’s Experience Center. Now, post competition and soon ready to join the workforce, Richard expects to tap the advantages of SLS technology in any of her future robotics design endeavors.

“The whole rover project was getting a looking glass into different and new technologies we didn’t know,” she says. “It was really amazing.”

Watch this video for more on how the FHNW students built a functional Mars rover with SLS 3D printed parts on board.