This robot was designed for and competed in the RoboMaster North America 2024 1v1 tournament.

I was responsible for designing the gimbal with the shooting system and 3D printing all the parts for the robot. The purpose of the shooting system is to store and shoot a maximum of 200 rounds of 17mm plastic pellets near 30m/s. The gimbal is required to support the Yaw and Pitch movement of the shooting system.

Design Requirements:

1.      Lightweight and compact to allow the gimbal to turn faster and more accurately by the driver, reduce the stress on the motors, and make the fine-tuning work for the gimbal less challenging.

2.      Stable and Reliable pellet-feeding and flywheel system to eliminate jamming situations

3.      Strong Cover Plates to protect vulnerable components  (wires, ESCs, control boards) from highspeed incoming pellets from opponents.

4.      Cost-effective design and manufacture as the budget is limited for a first-year student team.

Design Highlights:

1.      Structural design: The main structure of the shooting systems and gimbal consists of 4 sheet metal plates connected by two symmetric CNC machined parts. Cutouts were made with the guidance of SolidWorks FEA simulation results to further reduce the weight without sacrificing strength. This design provides superior structural strength (withstood airline carry-on shipping twice with minimum protection) while staying lightweight and low-cost for manufacturing.

2.      Pellet Feeding System: Considering the geometry of the pellets and the motor used for indexing, the components of the pellet feeding system would be complex for traditional manufacturing methods, which would significantly limit design freedom. Therefore, the system was decided to be completely 3D printed. After numerous prototyping and testing, the shape of the indexer and container was selected. The final product was printed using PETG for surface smoothness, durability, and temperature resistance.

3.      Pitch Motor Placement: The motor selected for pitching movement is relatively heavy thus requiring to be placed low to the chassis and as close to the Yaw axial as possible. To achieve the goal, a multi-link structure was used to move the motor from the side of the pitch axial to the center of the Yaw movement without compromising the pitch range of motion.

4.      Cover Plates: The exteriors for the shooting system are 3D-printed parts using normal PLA materials. Still, with the correct structural design specifically for 3D printing and well-thought printing orientation, layers, and infill patterns, all the 3D-printed parts held up well against thousands of pellet shots during ten intense matches.

Originally, the cover plates for the chassis were designed to be 3D printed. However, for the ease of shipping, it was later pivoted to consist of several modular carbon fibre plates mounted by thumb screws for convenient access for testing and debugging. The lightweight chassis cover offered excellent protection for all the control boards, wires, and supercapacitors inside the chassis.