BXI-85 Joint Actuator: 40 N·m Rated, 150 N·m Peak Torque

The BXI-85 is the high-torque flagship of the BXI joint actuator family. It is the joint that lets Ludu 3 squat, jump and climb — and it is available as a standalone module for your own robot.

Specifications

Built for high-load joints

BXI-85 is designed for the most demanding positions on a humanoid or legged robot: thigh and knee joints, the waist, and heavy-payload arm shoulders. In Ludu 3 it serves as the knee actuator, where 150 N·m of peak torque supports dynamic squatting, jumping and cushioned landings.

Hollow wiring and dual encoders

A 10 mm hollow shaft routes power and signal cables through the joint center — no external cable loops to snag, and a clean silhouette for consumer-facing designs. Inside, dual encoders (magnetic + inductive) and a cross-roller bearing deliver accurate, compliant torque control under the MIT protocol.

One family, one protocol

BXI-85 shares its CAN FD MIT-protocol interface with BXI-70 and BXI-50, so a complete robot can mix all three sizes on the same bus. Our roadmap adds five new BXI models in Q4 2026, extending peak torque up to 320 N·m.