An open-source BLDC motor test bed utilizing ESC telemetry for cost-effective educational laboratories

Hands-on motor characterization is essential in engineering education, but commercial dynamometers often exceed USD 15,000. This paper presents an open-source BLDC motor test bed that reduces cost by combining off-the-shelf e-bike components, ESC-native telemetry, an ESP32 controller, and a floating-caliper torque measurement mechanism. The Votol EM-50 ESC provides voltage, current, speed, and temperature telemetry, reducing the need for external electrical instrumentation, while a low-cost load cell and HX711 amplifier measure braking torque through a calibrated lever arm. Beyond hardware implementation, the platform integrates experimental validation with a dq-axis-based BLDC motor model to support interpretation of speed response, torque estimation, and transmission losses. Validation showed electrical measurement errors below 3%, torque error below 5%, expanded torque uncertainty below 0.5%, and model-versus-experiment speed-response agreement with an RMSE of 14.8 rpm. The complete system costs USD 370-488 and is supported by open firmware, wiring diagrams, bill of materials, experimental data, assembly documentation, and supplementary videos archived on Zenodo and GitHub.