Our project was the ARLISS competition project, more specifically the second part of the project where the vehicle must survive a drop and drive to a known location over rough desert terrain. We interviewed our professor, Dr. Potter, who had previous experience with the project to understand what was required in our design. The project started with creating concept ideas and deciding on one, which initially was an airplane to avoid designing a landing mechanism and having to drive over rough terrain. However, this design proved to have too many flaws and was scrapped. The new design was a small rover with a single motor and a oneway bearing with a parachute attached. Most of the parts in this design were 3D printed, save for the axle, parachute, battery, steel rod supports, and the oneway bearing. This design choice greatly reduced the overall weight of the design, giving us room to add extra components if necessary. Our initial prototype used PLA filament for the wheels and had the parachute in the center of the axle. This caused the parachute to not open up entirely when the rover was dropped. The battery also shifted during the drop, changing the center of gravity and making the rover fall on its wheel at an angle, causing the axle to be damaged. After these results, we redesigned the rover by focusing on the wheels, axle, the parachute, and brackets holding the battery. We designed the brackets to hold the battery at the rover’s center of gravity. Since we had extra weight to spare, we changed the axle from aluminum to steel to improve the strength of the rover. A second parachute attachment was added and the parachute attachments were moved to the ends of the axle to allow the parachute to open up more. The wheels were changed from PLA material to TPE to make the wheels more flexible and able to absorb more of the impact when the rover lands on the ground. When re-testing our final prototype, the rover was able to transverse over more rough terrain. The rover was also able to survive multiple drops without any significant damage and was able to operate after being dropped.
Mechanical Engineering Design Project (MEMS 411)
Bailey, Preston; Stelwagon, Zach; Reynolds, Cal; and Hardy, James, "Group S- ARLISS Project" (2019). Mechanical Engineering Design Project Class. 113.