Unitree J288 Brushless Digital Servo

Unitree J288 (Model: YS-342026-J288) is a high-performance brushless digital servo motor and actuator module developed by Unitree Robotics (Model: YS-342026-J288) specifically tailored for embodied intelligence, robotic joints, and dexterous hands.

It serves as the heavy-duty, upgraded counterpart to the entry-level plastic S288 model, replacing plastic components with steel gears and an aluminum alloy housing to drastically improve structural impact resistance, life cycle, and heat dissipation.

Unitree YS-342026-J288 Digital Servo Actuator Specifications:

Mechanical & Physical Specifications
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- Dimensions (W x H x D): 20 mm x 34 mm x 26 mm
- Weight: 35.0 g
- Housing Material: Anodized aluminum alloy shell
- Gear Train Material: Toughened steel gears
- Gear Ratio: 288.35:1 (Spur gear design)

Performance & Electrical Specifications
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- Input Voltage: 6.4V – 25.2V (Recommended: 25.2V)
- Maximum Speed: 35.0 rad/s (~334 rpm) @ 25.2V
- Maximum (Stall) Torque (Same Direction): 0.5 Nm (when external torque matches rotational speed direction)
- Maximum (Stall) Torque (Opposite Direction): 1.5 Nm (when external torque opposes rotational direction)
- Torque Constant: 0.554 Nm/A
- No-load Current: 0.45A @ 25.2V (0.27A @ 12V)
- Maximum Line Current: 1.92A

Communication & Control
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- Physical Interface: TTL level multi-point bus (Single-wire half-duplex asynchronous serial)
- Communication Protocol: Unitree Custom Protocol (8-bit, 1 stop bit, No Parity)
- Baud Rate: 6,000,000 bps
- Bus Capacity: Support for Address IDs 0–14 on a single master bus
- Operating Modes: Hybrid control mode supporting simultaneous Torque, Angle (8192 discrete steps), Velocity, Stiffness (Kp), and Damping (Kd) tuning
- Feedback Tracking: Dual 15-bit absolute encoders tracking both the internal rotor end and the external output end
- Telemetry Feedback: Streams real-time rotor torque, rotor angle, output angle, angular velocity, temperature, bus voltage, and error flags

Safety & Environmental
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- Operating Temperature: -20°C to +90°C
- Hardware Protection: Enhanced passive heat dissipation via aluminum shell; automatic driver board throttle/shutdown upon crossing thermal protection thresholds