Unitree Robotics · YS-342026-J288
Brushless Digital Servo J288
A compact metal-geared brushless servo with dual absolute encoders and high-speed serial control.
Available from Unitree Robotics. Price and stock are controlled by Unitree.
Product
What it is.
The J288 integrates a brushless high-speed motor, 288.35:1 spur gearbox, control board, temperature sensing, and dual absolute encoders in a 35 g aluminum-alloy package. It is intended for compact robot joints, dexterous hands, education, and rapid robotics development.
Specifications
Manufacturer-published, with the source attached.
Published J288 figures, kept distinct from Actuat measurements and design targets.
- Maximum stall torque
- 1.5N·mMFR
- Maximum no-load speed
- 35 rad/s @ 25.2 V / 16.5 rad/s @ 12 VMFR
- Input voltage
- 6.4 – 25.2VMFR
- Dimensions (W × H × D)
- 20 × 34 × 26mmMFR
- Weight
- 35gMFR
- Baud rate
- 6,000,000bpsMFR
Full specification table22
- Confirmed— A locked architectural decision
- Measured— From hardware, with stated conditions
- Simulated— Model output, not a specification
- Estimated— Calculated, not measured
- Manufacturer published— Third-party data, not independently verified
- Design target— Engineered toward
- Under evaluation— Options still open
- TBD— Not yet defined
Configuration
- Motor type
- Brushless motor
- Manufacturer published
- Gear type
- Spur gear
- Manufacturer published
- Gear material
- Steel
- Manufacturer published
- Shell material
- Aluminum alloy
- Manufacturer published
- Gear ratio
- 288.35:1
- Manufacturer published
- Dimensions (W × H × D)
- 20 × 34 × 26mm
- Manufacturer published
- Weight
- 35g
- Manufacturer published
Electrical
- Input voltage
- 6.4 – 25.2V
- Manufacturer published
Unitree lists 25.2 V as the recommended and maximum input for J288.
- No-load current
- 0.45 A @ 25.2 V / 0.27 A @ 12 V
- Manufacturer published
- Standby current
- 0.026 A @ 25.2 V / 0.05 A @ 12 V
- Manufacturer published
Performance
- Maximum no-load speed
- 35 rad/s @ 25.2 V / 16.5 rad/s @ 12 V
- Manufacturer published
Approximately 334 rpm at 25.2 V and 157 rpm at 12 V.
- Torque constant
- 0.554N·m/A
- Manufacturer published
- Maximum stall torque
- 1.5N·m
- Manufacturer published
Published for torque opposite to the direction of rotational speed.
- Operating temperature protection
- −20 °C minimum; 90 °C board / 120 °C winding shutdown
- Manufacturer published
Control and communication
- Position sensors
- Dual absolute encoders, rotor and output
- Manufacturer published
- Rotor encoder resolution
- 15bit
- Manufacturer published
- Baud rate
- 6,000,000bps
- Manufacturer published
- Protocol
- Unitree custom protocol
- Manufacturer published
Half-duplex asynchronous serial: 8 data bits, 1 stop bit, no parity.
- Physical connection
- TTL-level multi-point bus
- Manufacturer published
- Device ID range
- 0 – 14
- Manufacturer published
- Control mode
- Hybrid control
- Manufacturer published
Rotor torque, angle, angular velocity, stiffness, and damping commands.
- Feedback
- Torque, rotor/output angle, velocity, temperature, voltage, error status
- Manufacturer published
Applications
Where it fits.
Robot joints
Compact actuation with position, velocity, and torque feedback.
Dexterous hands
Small, backdrivable drives for tightly packaged mechanisms.
Research and education
Instrumented hardware for controls, mechatronics, and embodied AI.
Robot competitions
Integrated motion hardware for fast prototype cycles.
Building something that needs to move well?
Tell us what the machine has to do.