Apple Pi Robotics

Swerve drive is a type of drivetrain where each wheel can rotate independently which allows for full holonomic motion. Previous designs had little to no documentation or testing procedures, and numerous failure points.

 

When I took over the design process I started with an FMEA on my team’s prior design to understand where it was failing and how I could improve. One of the main problems with the design was how slow it was to manufacture. The module was also significantly bulkier and heavier than it needed to be. Screws in tapped holes repeatedly came loose, the wheel diameter was very small which led to rapid wear, and use of chains to drive the wheel created significant backlash.

 

My first goal in designing the new modules was reducing the number of operations required to manufacture the modules. I replaced one of the bushings with a 3D printed part and the other bushing could be manufactured in house rather than relying on a sponsor. I removed over a dozen screws from the design, and replaced the majority of tapped holes with nylocks. 

 

To expedite the assembly and machining process I created a detailed machining and assembly guide. I highlighted critical parts of the manufacturing process, and outlined tests the machinist could perform to ensure the part is manufactured and assembled correctly.

 

I increased the wheel size from 2” to 4”, which allowed for a lower overall gear ratio and less wear on the wheels. I also replaced the module from gear and chain driven to belt driven which almost entirely eliminated backlash.

 

I wanted to make sure the knowledge I gained from redesigning the modules was not lost when I left the team. So I mentored younger students in the design and involved them in the assembly process. Because of my success, I was invited to present at the regional and world level to over 600 people on my design process.