ARC Robotics Competition
I joined five other students to design and build a 20 lb robot, about 0.6 by 0.6 m, for a competition that came down to picking up cubes and placing them precisely. My part was the two-degree-of-freedom wrist. It rolls continuously through 360 degrees on a slip ring and pitches 180 degrees, so the end effector has a full hemisphere to work in. To get there I iterated the gear train to cut backlash and stiffen it, added on-axis encoding for control, and built in hardstops and active cooling so a stalled motor wouldn't kill it mid-test.
The parts were mine end to end. I drew them to GD&T, cut them on the waterjet, milled and tapped them against a fixture plate, pressed the bearings in on the lathe and mill, and assembled the wrist by hand. The electronics mount I topology-optimized in nTop. Beyond the wrist, the robot ran slip rings on the turret yaw and wrist roll for continuous rotation, three passive omni-wheels for odometry, and a suction end effector.
