--- title: "MyActuator RMD-X8 Pro V2 (1:9) specs" description: "Integrated Joint actuator from MyActuator (China). Peak torque 25 Nm, rated 13 Nm, weight 710 g, torque density 35.2 Nm/kg, price $557.24." canonical: https://actuatorlist.com/actuators/myactuator-rmd-x8-pro-v2 last-updated: 2026-11-01T14:05:43.000Z --- # RMD-X8 Pro V2 (1:9) by MyActuator > Integrated Joint actuator from MyActuator (China). Peak torque 25 Nm, rated 13 Nm, weight 710 g, torque density 35.2 Nm/kg, price $557.24. ## Specifications | Spec | Value | | --- | --- | | Category | Integrated Joint | | Peak torque | 25 Nm | | Rated torque | 13 Nm: Revision conflict: retained 13 N·m legacy rating; current X8-25 documents specify 10 N·m. Applicability unconfirmed. | | Max speed | 160 rpm: Revision conflict: retained 160 rpm legacy no-load value; current curve lists 254.3 rpm at 48.14 V. Applicability unconfirmed. | | Gear ratio | 9:1 | | Weight | 710 g | | Torque density | 35.2 Nm/kg: Revision scope: density is peak torque / mass (25 N·m / 0.710 kg). Current peak and mass agree; the 13-to-10 N·m rated-torque conflict does not change this density. Confirm installed revision. | | Price | $557.24 | | Price per Nm | $22.3 | | Backdrivable | n/a | | Backlash | n/a | | Voltage | 24-48 V: Revision conflict: retained 24–48 V legacy range; current actuator sheet specifies 48 V. Driver range is not actuator rating. | | Peak current | n/a | | Communication | CAN, RS-485 | | Control modes | position, velocity, torque | | Encoder | 18-bit magnetic: Revision conflict: current 240814 sheet says 16-bit, while 241227 manual says 18 bits. Confirm installed revision; resolution is not accuracy. | | Integrated driver | yes | | Availability | in production | | Data status | Revision conflict: unresolved | ## Size a joint - [Motor torque calculator](/tools/motor-torque-calculator?solve=power&t=13&n=160): **218 W** of shaft power at its rated 13 N·m and 160 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=0.71,0.5,0&p=2): **32.8 N·m** at the shoulder with its 710 g at the elbow of a 2 kg-payload arm. ## Use cases - robot arm - quadruped leg - exoskeleton ## Notes Popular arm/leg joint module. Peak 25 N.m and rated 13 N.m per RobotShop/MyActuator; nominal ~122 rpm, ~160 rpm no-load at 48 V. Net weight 710 g per manufacturer/factory listings. Priced at $557.24 on RobotShop (USD). ## Engineering evidence **Revision scope:** RMD-X8-Pro 1:9 V2 / current X8-25 alias; unchanged winding/driver/firmware not established - Current X8-25 documents rate 10 N·m / 125 W / 110 rpm versus legacy 13 N·m / 166 W / 122 rpm and 160 rpm no-load. Catalog fields are retained, not revalidated. - Current sheet says 48 V; legacy says 24–48 V. IP54 and brake are customization options, not established standard-unit features. Document review, not bench validation. ### Efficiency **Evidence: manufacturer.** Current X8-25 curve prints 80.8%, 7.19 N·m, 242.0 rpm, 47.99 V, 4.676 A, 224.36 W input and 181.30 W output; source arithmetic discrepancy: torque × angular speed gives 182.21 W and 81.21% of printed input, not the printed output/efficiency. **Scope / unknowns:** Printed values are retained, not corrected; not a coherent verified operating point. Current characteristic sweep only; applicability to the legacy catalog unit is unconfirmed. Electrical metering location, driver/cable loss boundary, thermal state, dwell and uncertainty are unspecified; not a verified bus-to-output map or continuous-duty guarantee. **Source locators:** - [X8-25 product archive](https://www.myactuator.com/_files/archives/cab28a_85824a1893de4b058080c363664a1c9f.zip): 240814 product parameter PDF p1, Motor Characteristic Curve summary/table - [X Series V2 manual archive](https://www.myactuator.com/_files/archives/cab28a_82abda57fa5a4db1b99e86d416ba2e94.zip): X Series-V2 Product Manual-241227.pdf, PDF p5 / printed E-11/12, characteristic curve ### Thermal duty **Evidence: manufacturer.** Current rated-torque footnote specifies 24 °C ambient, no other heat dissipation, rated speed and 60 °C rise to thermal equilibrium. **Scope / unknowns:** Applies to current 10 N·m / 110 rpm, not the legacy 13 N·m rating without confirmation. Sensor location, fixture conduction, equilibrium criterion, repeated peak duty and recovery remain unknown. **Source locators:** - [X Series V2 manual archive](https://www.myactuator.com/_files/archives/cab28a_82abda57fa5a4db1b99e86d416ba2e94.zip): X Series-V2 Product Manual-241227.pdf, PDF p5 / E-11/12, rated-torque footnote ### Precision **Evidence: manufacturer.** 240814 sheet says 16-bit input encoder; 241227 manual/current page say 18 bits. Current backlash is 10 arcmin versus legacy 5 arcmin. **Scope / unknowns:** Installed revision remains unresolved. Encoder resolution/backlash do not establish loaded output accuracy or bidirectional repeatability; those remain unknown. **Source locators:** - [X8-25 product archive](https://www.myactuator.com/_files/archives/cab28a_85824a1893de4b058080c363664a1c9f.zip): 240814 product parameter PDF p1, encoder/backlash table - [X Series V2 manual archive](https://www.myactuator.com/_files/archives/cab28a_82abda57fa5a4db1b99e86d416ba2e94.zip): X Series-V2 Product Manual-241227.pdf, PDF p5, encoder/backlash table - [Legacy manufacturer manual (RobotShop mirror)](https://cdn.robotshop.com/media/M/Mya/RBC-Mya-19/pdf/RMD-X%20V2%20Series%20Product%20Manual.pdf): PDF p9 / printed pp15–16, X8-Pro V2 1:9, item A00085; revision date unresolved ### Modeling **Evidence: manufacturer.** Official X8-25 archive contains drawings and AP214 STEP geometry whose HEADER identifies RMD-X8pro-P9 V2.step, exported by SolidWorks 2020. **Scope / unknowns:** Geometry/tabulated inertia are not identified friction, compliance, control delay or validated sim2real dynamics. Driver V3 / protocol V4.2 cover does not establish compatibility with the catalog MC-X-300-O hardware/firmware; calibrated model remains unknown. **Source locators:** - [X8-25 product archive](https://www.myactuator.com/_files/archives/cab28a_85824a1893de4b058080c363664a1c9f.zip): Archive drawing/STEP members; RMD-X8pro-P9 V2.step HEADER, 2023-12-27 - [Driver/protocol archive](https://www.myactuator.com/_files/archives/cab28a_82abda57fa5a4db1b99e86d416ba2e94.zip): MC driver manual V3.0 cover; protocol PDF p1, Applicable driver V3 / Version V4.2 / 2024.05 ## Sources - [https://www.robotshop.com/products/my-actuator-rmd-x8-pro-v2-can-bus-bldc-actuator-w-19-reduction-mc-x-300-o-driver](https://www.robotshop.com/products/my-actuator-rmd-x8-pro-v2-can-bus-bldc-actuator-w-19-reduction-mc-x-300-o-driver) - [https://www.myactuator.com/x8-25-details](https://www.myactuator.com/x8-25-details) - [https://www.alibaba.com/product-detail/RMD-X8-pro-1-9-V2\_1600294507504.html](https://www.alibaba.com/product-detail/RMD-X8-pro-1-9-V2_1600294507504.html) ## 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 - [RMD-X8-120 (MyActuator)](https://actuatorlist.com/actuators/myactuator-rmd-x8-120): 85.7 Nm/kg ## Catalog comparisons Catalog specifications and source caveats, not compatibility recommendations. - [EC-A4310-P2-36 vs RMD-X8 Pro V2 (1:9)](/comparisons/encos-ec-a4310-p2-36-vs-myactuator-rmd-x8-pro-v2) - [MG5010E-i36 V3 vs RMD-X8 Pro V2 (1:9)](/comparisons/lkmtech-mg5010e-i36-v3-vs-myactuator-rmd-x8-pro-v2) - [RMD-X8 Pro V2 (1:9) vs GIM6010-36 (48V)](/comparisons/myactuator-rmd-x8-pro-v2-vs-steadywin-gim6010-36) [Browse actuator comparisons](/compare). ## Machine-readable - JSON: https://actuatorlist.com/api/v1/actuators/myactuator-rmd-x8-pro-v2 - Catalog index for agents: https://actuatorlist.com/llms.txt