The open-source NEMA 17 servomotor integrates the motor, driver, motion controller, and encoder into a single compact unit.
The Gearotons M17 is an open-source servomotor designed to combine four components normally required for a motion axis: the motor, driver, motion controller, and encoder. The integrated design follows the standard NEMA 17 form factor, with no external driver or controller boards protruding from the motor. Gearotons says this reduces wiring and configuration work while keeping the system suitable for robotics, CNC machines, automation, scientific instruments, and 3D printers.
At the centre of the motor is an STMicroelectronics STM32G0 Arm Cortex-M0+ microcontroller. Position feedback comes from the built-in encoder, with a PID control loop operating at 32 kHz for closed-loop motion control. The motor can reach up to 560 RPM and is designed to provide a torque-to-weight ratio comparable to an equivalent stepper motor, while using less power during closed-loop operation.
The M17 family is available in four versions: M17-60, M17-48, M17-40, and M17-34. Rated torque ranges from 0.28 Nm on the M17-34 to 0.65 Nm on the M17-60, while the motor height varies from 33.5 mm to 59.7 mm. All four models use the same 42.2 × 42.2 mm NEMA 17 mounting footprint and a 5 mm shaft. They operate from a 12–24 V DC supply and include over-current, over-voltage, and over-temperature protection.
Communication is handled through RS-485 at 230400 baud, which also allows multiple motors to be connected on the same bus. Each motor has a factory-assigned 64-bit unique ID and can also be assigned a one-byte alias for shorter commands. The interface supports motion control, configuration, status monitoring and firmware updates, while host-side libraries are available for Python and Arduino. Raspberry Pi, Arduino, ESP32, Mac and PC systems can control the motors using an RS-485 adapter.
The M17 is being released as an open-source hardware and software platform, with firmware, software and PCB design files published on GitHub. Gearotons is positioning the motor for applications ranging from robotics and CNC equipment to automated test systems and education. With the motor, driver, controller and encoder integrated into one NEMA 17-compatible unit, the platform aims to simplify the construction of multi-axis machines while retaining a standard mechanical mounting format.
