Problem

Our client, Bob, a quadriplegic individual, desired a way to independently participate in dart throwing, a recreational activity traditionally reliant on manual dexterity and precise control. Due to his limited mobility, Bob needed a robust, reliable, and user-friendly mechanical system that could safely and accurately replicate the dart-throwing motion, enabling him to participate actively in this engaging pastime.

Design

Our final mechanical design featured a custom 3D-printed grip controlled by a compact servo motor, allowing for reliable dart holding and release. A rotating arm powered by a stepper motor provided consistent throwing motions. Precise aiming capabilities were achieved using a two-axis gimbal system employing two high-precision stepper motors, all securely mounted on an adaptable 80/20 aluminum frame. The integration of an Arduino Mega microcontroller enabled responsive control of all mechanical components via inputs from a PlayStation controller to mirror an adaptive controller.

Testing

Iterative testing was integral to our development process. Extensive trials were conducted to refine parameters such as arm rotation speed, grip release timing, and gimbal positioning. By systematically adjusting these variables, we optimized the dart’s trajectory, improved accuracy, and ensured reliability across repeated uses. Through this rigorous testing process, we continually improved both the mechanical performance and electronic responsiveness of the system.

Results

The final device successfully achieved all initial design goals. Our system delivered darts at a speed of 19 feet per second with consistent accuracy and precision. It also met the critical usability goal, enabling Bob to independently complete three dart throws in under three minutes. Beyond meeting project specifications, this experience significantly expanded my personal skill set, enhancing my proficiency in coding, electronic wiring, microcontroller integration, and collaborative engineering design.