Agility Robotics cycloidal actuator
The cycloidal actuator is Agility Robotics' proprietary drive technology used in the Digit 5 humanoid, unveiled on September 15, 2026. According to the company, a new leg design powered by cycloidal actuator technology is engineered to withstand repetitive lifting and lets Digit 5 repeatedly lift up to 50 lb (about 22.7 kg) — 40% more payload than Digit 4.
Digit 5 abandons the bird-like, backward-bending knees for more human-like legs optimized for lifting heavy loads and for frequently getting up and kneeling (with knee padding). The robot is designed, developed and assembled in the U.S. (RoboFab, Salem, Oregon). Note: Agility publicly ties cycloidal actuators to durability under repetitive lifting; it has not disclosed torque, power, gear ratio, actuator count, or whether cycloidal drives are also used in the arms. Digit 5 remains in development (early access H1 2027, general availability by end of 2027).
Classification
Cycloidal actuator · serves as: Actuator, Joint Actuation, Gear Reduction.
Which group Agility Robotics cycloidal actuator belongs to and how it is built
A cycloidal actuator is a drive unit combining a motor with a cycloidal drive, in which a cycloidal disc rolls against a ring of pins to deliver a high reduction ratio in a compact housing. The design provides high torque, high stiffness and resistance to shock loads, which is why it is used in robot joints that must repeatedly lift heavy masses.
Relations
Robots in which Agility Robotics cycloidal actuator is or can be used
