This is the joint actuator Unitree builds into its Z1 6-axis robot arm, supplied as a separate part for teams that run Z1 arms and need a replacement or a spare joint. It combines the motor with a harmonic reducer and an industrial-grade crossed roller bearing in a compact Φ65 × 52 mm housing weighing 405 g.
Unitree rates it at 33 N·m maximum torque with about 6 arcmin of backlash and a reduction ratio of 60 and above. A 15-bit encoder and a 1 kHz control frequency over RS-485 support the arm's force control, with a force-control accuracy of about 0.2 N·m. The motor reports torque, angle and angular velocity, and accepts torque, angle, angular velocity, stiffness and damping commands; 24 V is the recommended supply.
These joints give the Z1 its position-plus-force control and collision detection, and they also explain a trait Unitree is open about: because the reduction ratios are relatively low, the arm's position-control stiffness is low, and without an optimised control mode it can show position error and shake in motion. Which of the arm's six joints the part fits, whether it suits your Z1 Air or Z1 Pro, and the replacement procedure are confirmed in writing with your quotation.
Key Capabilities
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Harmonic Reducer, 60+ Ratio: A harmonic reducer with a reduction ratio of 60 and above runs on an industrial-grade crossed roller bearing.
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33 N·m Maximum Torque: Unitree rates the actuator at 33 N·m peak, with backlash of about 6 arcmin.
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Force Control to About 0.2 N·m: Torque, angle and angular-velocity feedback support the Z1's force control and collision detection.
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1 kHz Control over RS-485: Commands cover torque, angle, angular velocity, stiffness and damping at a 1 kHz control frequency.
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Compact 405 g Body: The Φ65 × 52 mm housing keeps the arm's joints light, with a recommended 24 V supply.
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Fit Confirmed Before Order: Joint position, arm version and replacement procedure are confirmed in writing with the quotation.
Buying through Robotix Market
This unit is sourced new through established distribution channels and ships worldwide with the full manufacturer warranty. Technical support is coordinated with the manufacturer's own service network. Deployment scope, configuration, and commissioning responsibilities are agreed as part of the quotation — on-site installation is not included in the product price.
