Actuators & Motion

Feetech

The $20 bus servo inside every SO-101 follower arm.

Stall torque

19.5 kg·cm @ 7.4 V

Gearing

1:345 metal

Encoder

12-bit magnetic

Interface

Serial bus

Feetech

Leader-arm gearing for SO-101 teleop pairs.

Stall torque

19.5 kg·cm @ 7.4 V

Gearing

1:191 metal

Encoder

12-bit magnetic

Interface

Serial bus

Damiao

Open-source QDD joint module for custom robot arms.

Torque

4 N·m rated / 10 peak

Gearing

10:1 planetary

Encoders

Dual

Interface

CAN, MIT mode

ODrive

Precision FOC controller with manufacturer support.

Channels

1

Voltage

12–50.5 V

Control

FOC, CAN / USB

Firmware

Open API

Damiao

40:1 sibling for knees, hips and exoskeleton joints.

Gearing

40:1

Encoders

Dual

Interface

CAN, MIT mode

Variant

+$20 cross-roller (P)

Damiao

80 mm-class QDD for quadruped legs.

Frame

80 mm class

Gearing

6:1

Encoders

Dual

Interface

CAN

RobStride

QDD joint module with 60 N·m peak torque.

Torque

60 N·m peak

Gearing

9:1

Density

66.7 N·m/kg

Interface

CAN

RobStride

QDD joint module with 120 N·m peak torque.

Torque

120 N·m peak

Gearing

9:1

Density

85.7 N·m/kg

Interface

CAN

Unitree

The Go-series joint motor, sold as a component.

Torque

23.7 N·m peak

Gearing

6.33:1

Encoder

Dual

Interface

RS485

CubeMars

Widely used QDD joint module for robotics research.

Torque

8.3 N·m rated / 24.8 peak

KV

100

Protocol

MIT / CAN

Series

AK

CubeMars

22 N·m peak joint module for legged robots.

Torque

22 N·m peak

KV

100

Protocol

MIT / CAN

Series

AK

Leaderdrive

China's largest harmonic maker: MOQ 1 through us, English datasheets.

Sizes

14 / 17 / 20 / 25

Accuracy

Arc-second class

MOQ

1 unit (via us)

Docs

English datasheets