As an undergraduate researcher in Pieter Abbeel's Robot Learning Lab, I worked on Blue, a 7-degree-of-freedom low-cost robotic arm. The project is designed to bring robotics closer to home and into research labs across the world with a projected cost of $5000.
Since June 2017, a total of 13 individuals have contributed to the project, designing the robot from the ground up, resulting in a paper! The only off-the-shelf components are the brushless motors, making the cost of the robot dependent on our component design decisions.
Over the years, I've worn many hats in the group. My primary role was maintaining the motor controller boards which have turned into a stand-alone open source project.