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Integrated robot joint actuator

RobStride 03 (RS03) integrated robot joint actuator

Quasi-direct-drive joint actuator with a 9:1 reduction giving 20 Nm rated and 60 Nm peak at 48 V, 200 rpm no-load, 14-bit absolute encoder and CAN 2.0 at 1 Mbps, in an 880 g package.

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  2. 2Performance
  3. 3Environment
  4. 4Volumes
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What are you specifying?

Select everything you need. A motor, drive and gearbox can be specified together as one axis.

1 selected: Gearbox or harmonic drive

Key specifications

Voltage (max)60 V
Temperature-20–50 °C
Data / busCAN 2.0 (1 Mbps, extended frame)
Rated torque (max)20 Nm
Peak torque (max)60 Nm
Speed (max)200 rpm
Rated speed180 rpm
Supply24–60 VDC (48 V rated)
Feedback14-bit single-turn absolute encoder
Continuous current (max)13 A
Peak current (max)43 A
Ratio9–9:1
Resolution (max)14 bit
Weight880 g
InsulationClass B

Summarised in our own words from Beijing Lingzu Times Technology Co., Ltd. (RobStride Dynamics)'s published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1

Notes on this data

From the RS03 user manual. The manual's parameter table lists GearRatio 64, which conflicts with the 9:1 ratio stated in section 1.4.5; 9:1 used here, confirm with the maker. Currents are phase current peaks. RobStride 01, 04, 05 and 06 exist but their pages are script-rendered and could not be read.

Specify Motion is not affiliated with Beijing Lingzu Times Technology Co., Ltd. (RobStride Dynamics). RobStride and RobStride 03 (RS03) are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.

RobStride 03 (RS03) replacement and alternative options

Use these supply-network options as a starting point for an engineering check. We can also help source the original RobStride part. Published series figures do not establish an exact-model or drop-in replacement: confirm ratings, fit, interfaces and approvals for your application.

Planetary gearbox

Wanshsin WSH

Limited published data: 3 figures compared

High-rigidity Wanshsin inline planetary with three backlash classes down to super-precision, for machine tools, automation and AGVs.

Published maximumRobStride 03 (RS03)WSH
Peak torque60 Nm7,200 Nm meets or exceeds
Rated torque20 Nm2,400 Nm meets or exceeds
Speed200 rpm6,000 rpm meets or exceeds
Spiral bevel gearbox

Wanshsin WSHR

Limited published data: 3 figures compared

Right-angle version of the high-rigidity WSH, with a spiral bevel stage and ratios up to 200:1.

Published maximumRobStride 03 (RS03)WSHR
Peak torque60 Nm4,200 Nm meets or exceeds
Rated torque20 Nm1,400 Nm meets or exceeds
Speed200 rpm6,000 rpm meets or exceeds
Planetary gearbox

Wanshsin WTH

Limited published data: 3 figures compared

Wanshsin inline planetary designed for high radial loads, offered in three precision classes.

Published maximumRobStride 03 (RS03)WTH
Peak torque60 Nm6,150 Nm meets or exceeds
Rated torque20 Nm2,050 Nm meets or exceeds
Speed200 rpm6,000 rpm meets or exceeds

Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.

Typical applications

Legged robotsHumanoid robotsLightweight automation

What an integrated robot joint actuator is

An integrated robot joint actuator packages a brushless motor, a reduction gear, encoders, a servo drive and often a brake or torque sensor into one module that bolts in as a robot joint. Gearing may be planetary, strain-wave or cycloidal. Many are designed for legged robots, humanoids and cobots, with low gear ratios or quasi-direct drive to keep the joint back-drivable and responsive. Communication is typically over CAN or EtherCAT, with position, velocity and torque control modes.

When engineers choose an integrated robot joint actuator

Choose an integrated joint actuator to build robots faster with fewer parts, especially legged, humanoid, exoskeleton and collaborative robots. Back-drivable versions suit force control and impacts. The trade-offs are torque density, precision and industrial qualification: low-ratio designs trade output torque for transparency, and some units are aimed at research rather than production duty. For industrial arms with heavy duty cycles, a dedicated harmonic actuator or motor and gear set may be better.

How to specify the RobStride 03 (RS03)

Send these with your enquiry and an engineer can confirm the right RobStride 03 (RS03) variant or an equivalent:

  • Peak and continuous output torque (Nm)
  • Output speed (rpm)
  • Gear type and ratio
  • Back-drivability and torque sensing
  • Supply voltage (V DC)
  • Communication interface and control modes
  • Mass and size (kg, mm)

Common mistakes to avoid

  • Using peak torque as continuous torque
  • Ignoring thermal limits in legged robots
  • Overlooking bus bandwidth with many joints
  • Assuming research-grade units meet industrial life requirements

RobStride 03 (RS03): frequently asked questions

Can you help replace RobStride 03 (RS03) or source the original?

Send the full model code, quantity and required date. Our engineers can check original-part availability and assess suitable alternatives, including supply-network options where appropriate. We confirm compatibility and any changes needed before recommending a replacement.

What is the RobStride 03 (RS03)?

Quasi-direct-drive joint actuator with a 9:1 reduction giving 20 Nm rated and 60 Nm peak at 48 V, 200 rpm no-load, 14-bit absolute encoder and CAN 2.0 at 1 Mbps, in an 880 g package. Published series figures include voltage 60 V, temperature -20 °C, temperature 50 °C, rated torque 20 Nm. It is made by Beijing Lingzu Times Technology Co., Ltd. (RobStride Dynamics); Specify Motion can help source it or propose an equivalent.

Who makes the RobStride 03 (RS03)?

The RobStride 03 (RS03) is made by RobStride (Beijing Lingzu Times Technology Co., Ltd. (RobStride Dynamics)) and is listed here for engineers comparing options. Specify Motion is not affiliated with Beijing Lingzu Times Technology Co., Ltd. (RobStride Dynamics); brand names are used only to identify the product.

What is the voltage of the RobStride 03 (RS03)?

The published series maximum voltage is 60 V. Individual models and sizes in the RobStride 03 (RS03) range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.

Is there an alternative to the RobStride 03 (RS03)?

We can assess suitable replacement options. On published figures, Wanshsin WSH and Wanshsin WSHR are options to assess from our supply network. An engineer confirms the fit against your application before recommending anything.

What is a quasi-direct-drive actuator?

A quasi-direct-drive actuator uses a high-torque motor with a low gear ratio, typically below about 10:1, so the joint is back-drivable and responds quickly to external forces. This suits legged robots and force control. The trade-off is lower output torque than high-ratio joints of similar size.

Why integrate the drive in a robot joint actuator?

Integrating the drive reduces cabling and lets each joint communicate over a shared bus, which simplifies robot design. It also allows the drive to sit close to the motor, improving control. The trade-off is that heat from both motor and drive must be managed inside the joint.

Further reading: How to select a harmonic actuator · Frameless motor sizing robot joints · Gearboxes and harmonic drives

Other integrated robot joint actuator series

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