---
title: "MyActuator RMD-X8-120 specs"
description: "Integrated Joint actuator from MyActuator (China). Peak torque 120 Nm, rated 43 Nm, weight 1400 g, torque density 85.7 Nm/kg, price $645."
canonical: https://actuatorlist.com/actuators/myactuator-rmd-x8-120
last-updated: 2026-11-01T14:05:43.000Z
---
# RMD-X8-120 by MyActuator

> Integrated Joint actuator from MyActuator (China). Peak torque 120 Nm, rated 43 Nm, weight 1400 g, torque density 85.7 Nm/kg, price $645.

## Specifications

| Spec | Value |
| --- | --- |
| Category | Integrated Joint |
| Peak torque | 120 Nm |
| Rated torque | 43 Nm |
| Max speed | 127 rpm |
| Gear ratio | 20:1 |
| Weight | 1400 g |
| Torque density | 85.7 Nm/kg |
| Price | $645 |
| Price per Nm | $5.4 |
| Backdrivable | no |
| Backlash | n/a |
| Voltage | 24-48 V |
| Peak current | n/a |
| Communication | CAN, EtherCAT |
| Control modes | position, velocity, torque |
| Encoder | dual 18-bit magnetic |
| Integrated driver | yes |
| Availability | in production |
| Data status | Catalog headline specs spot-checked: confirm revision |

## Size a joint

- [Motor torque calculator](/tools/motor-torque-calculator?solve=power&t=43&n=127): **572 W** of shaft power at its rated 43 N·m and 127 rpm.
- [Robot arm torque calculator](/tools/robot-arm-torque-calculator?L=0.4,0.35,0.12&m=1.2,0.8,0.3&a=1.4,0.5,0&p=2): **35.5 N·m** at the shoulder with its 1400 g at the elbow of a 2 kg-payload arm.
- [Humanoid robot actuators](/guides/humanoid-robot-actuators#hip): **6 of 7 joints** within its rated torque, up to the hip at 41.2 N·m.

## Use cases

- robot arm
- humanoid joint
- agv

## Notes

High-torque, large-hollow-bore planetary joint for arm base/humanoid joints. RMD-X8-P20-120: 120 N.m peak, 43 N.m rated, 127 rpm rated speed, 574 W, 1.40 kg per OpenELAB/RobotShop. Actual reduction ~19.6:1 (nominal 20:1). One reseller lists 110 N.m peak. EtherCAT and CAN driver variants.

## Sources

- [https://www.robotshop.com/products/myactuator-myactuator-brushless-dc-motor-rmd-x8-120-ethercat-large-torque-120nm-robot-joint-module-large-hollow-planetary-reduction-torque](https://www.robotshop.com/products/myactuator-myactuator-brushless-dc-motor-rmd-x8-120-ethercat-large-torque-120nm-robot-joint-module-large-hollow-planetary-reduction-torque)
- [https://www.dingsmotionusa.com/rmd-x8-120](https://www.dingsmotionusa.com/rmd-x8-120)
- [https://openelab.io/products/myactuator-rmd-x8-p20-actuator](https://openelab.io/products/myactuator-rmd-x8-p20-actuator)

## Similar Integrated Joint actuators

- [EC-A4315-P2-36 (ENCOS)](https://actuatorlist.com/actuators/encos-ec-a4315-p2-36): 154.6 Nm/kg
- [EC-A6416-P2-25 (ENCOS)](https://actuatorlist.com/actuators/encos-ec-a6416-p2-25): 149.1 Nm/kg
- [DM-J6248P-2EC (DAMIAO (DMBots))](https://actuatorlist.com/actuators/damiao-dm-j6248p-2ec): 147 Nm/kg
- [EC-A4310-P2-36 (ENCOS)](https://actuatorlist.com/actuators/encos-ec-a4310-p2-36): 94.2 Nm/kg
- [RobStride 04 (RobStride)](https://actuatorlist.com/actuators/robstride-04): 84.5 Nm/kg

## Catalog comparisons

Catalog specifications and source caveats, not compatibility recommendations.

- [EC-A4315-P2-36 vs RMD-X8-120](/comparisons/encos-ec-a4315-p2-36-vs-myactuator-rmd-x8-120)
- [EC-A6416-P2-25 vs RMD-X8-120](/comparisons/encos-ec-a6416-p2-25-vs-myactuator-rmd-x8-120)
- [RMD-X8-120 vs RobStride 04](/comparisons/myactuator-rmd-x8-120-vs-robstride-04)

[Browse actuator comparisons](/compare).

## Machine-readable

- JSON: https://actuatorlist.com/api/v1/actuators/myactuator-rmd-x8-120
- Catalog index for agents: https://actuatorlist.com/llms.txt