High-torque humanoid hip and knee joints
quasi-direct-drive actuator: 40 N·m rated / 120 N·m peak at 9:1, 200 rpm no-load at 48 V, 1420 g, Ø120 × 52.2 mm.
Engineering inference
RobStride
RobStride 04 QDD Actuator
RobStride 04 is the largest RobStride quasi-direct-drive joint: 40 N·m rated (at 100 rpm) and 120 N·m peak through a 9:1 reducer, 200 rpm no-load at 48 V, 27 A rated / 90 A peak phase current, 2.1 N·m/Arms torque constant, 14-bit absolute encoder, CAN 2.0 at 1 Mbps (RobStride, CANopen, MIT protocols). 24–60 V, 1420 g, Ø120 × 52.2 mm.
RS04Development boardPrice$295.00www.roboticscenter.ai · preorder
Buy at www.roboticscenter.ai Overview
Motor essentials
Facts about the complete product. Unknown values remain open design questions.
- Rated voltage
- 48 V
- No-load speed
- 200 RPM
- Gear reduction
- 9:1
- Encoder
- 14-bit absolute
A good fit for
Guidance to help you shortlist. The basis is shown for each recommendation.
Robotics and motor control
CAN 2.0 at 1 Mbps with RobStride private, CANopen and MIT protocols; operation (MIT-style), current, speed and two position modes; 14-bit absolute encoder.
Engineering inferenceNo-load speed, rated performance and stall limits describe different operating points. A stall specification is not a continuous operating rating.
3D model & CAD
3D model & CAD files
Generated from the datasheet's dimensioned drawing and measured against it. Download the STEP to check fit in your own enclosure.
- Envelope (L × W × H)
- 120 × 120 × 52.2 mm
- Verification
- generated
- Envelope complete
- Yes
Torque & control
Torque, speed and control
What the joint can deliver and how the controller talks to it.
- Type
- QDD
- Rated / peak torque
- 40 / 120 N·m
- No-load speed
- 200 rpm
- Encoder
- 14-bit absolute
- Control
- CAN · operation control (MIT-style), current, speed, position (PP), position (CSP)
| Connector | Type |
|---|---|
| power | XT30APW-M power (mates XT30UW-F, AMASS) |
| can | GH1.25-2PWT CAN (mates GH1.25-T) |
| swd | SWD download port (SWDIO, SWCLK, 3V3, GND) |
Rated torque is continuous; peak torque is short-duration. Values with two figures (e.g. 24/48 V) are per supply voltage.
Specifications
Motor performance
No-load, rated-load and stall figures retain their separate test conditions.
- Rated voltage
- 48 V
- No-load speed
- 200 RPM
- Continuous rated torque
- 40 N·m
- Rated-load speed
- 100 RPM
- Rated current
- 27 A
Stall torque and current are not continuous ratings. Check the duty cycle and starting load when choosing the driver and power supply.
Thermal limits by level
Product operating conditions, chip ambient ratings, package case limits and junction maxima remain separate.
Motor body
- Product operating range
- -20 to 50 °C
Mechanical dimensions
Reported product dimensions may exclude protruding components. Unknown height does not establish a complete clearance envelope.
- Length
- 120 mm
- Width
- 120 mm
- Reported height / thickness
- 52.2 mm
Attached generated geometry is an approximate envelope. A generated outline does not establish an electrically verified PCB footprint.
Board connectors
| ID / type | Pins | Pitch | Notes |
|---|---|---|---|
| powerXT30APW-M power (mates XT30UW-F, AMASS) | 2 | Unknown | — |
| canGH1.25-2PWT CAN (mates GH1.25-T) | 2 | Unknown | — |
| swdSWD download port (SWDIO, SWCLK, 3V3, GND) | 4 | Unknown | — |
Complete structured record
Every available field, including details beyond the summaries. Null means the value has not been established.
Sourcing & files
Supplier offers
US / USD is the target market. Observed price and stock are separate from a delivery quote.
www.roboticscenter.ai
US · USD
$295.00Minimum quantity unknown
- Observed stock
- preorder
- Checked
- Oct 17, 2026, 07:01 AM UTC
- Delivery estimate
- Not quoted
This observation is stale or has no verified check time. Recheck with the supplier.
Visit supplier (opens in a new tab)Delivery depends on quantity, postal code and shipping method. A dispatch statement such as “ship today” is not an arrival estimate.
Design files and references
Each source keeps its own verification status. Confirm the part revision and file contents before using it in a design.
Datasheet (opens in a new tab)
Manufacturer reference
RobStride 04 QDD actuator — product render, output face (Robotics Center) (opens in a new tab)
Unverified reference
inspected: round black RS04 housing, output face with a ring of small holes and a silver output hub; matches the p10 outline (Ø120 round body, no ears). Retailer image → unverified.
STEP (generated from datasheet drawing) — link unavailable
Generated asset
cad_check passed
Generated envelope geometry may also exist for this record. It does not replace manufacturer CAD or a verified electrical land pattern.
Source evidence
Document provenance, retrieval dates and the field groups supported by each source.
Supports: spec.constraints.electrical.supply_voltage_nominal_v, spec.constraints.thermal.operating_temp_max_c, spec.constraints.thermal.operating_temp_min_c, spec.geometry.body_diameter_mm, spec.geometry.body_length_mm, spec.geometry.cad.bbox.height_mm, spec.geometry.cad.bbox.length_mm, spec.geometry.cad.bbox.width_mm, spec.geometry.cad.envelope_complete, spec.geometry.cad.mesh_path, spec.geometry.cad.step_path, spec.geometry.cad.verification, spec.geometry.dimensions.height_mm, spec.geometry.dimensions.length_mm, spec.geometry.dimensions.width_mm, spec.geometry.other.weight_g, spec.provides.actuator_type, spec.provides.control_interface, spec.provides.control_modes, spec.provides.encoder, spec.provides.encoder_bits, spec.provides.features, spec.provides.gear_ratio, spec.provides.integrated_driver, spec.provides.kt_nm_per_a, spec.provides.motor_type, spec.provides.no_load_speed_rpm, spec.provides.other.insulation_class, spec.provides.other.pole_pairs, spec.provides.peak_torque_nm, spec.provides.rated_speed_rpm, spec.provides.rated_torque_nm, spec.usage.connectors, spec.usage.pinout, spec.usage.pinout_complete, spec.usage.requirements.other.peak_current_a, spec.usage.requirements.rated_current_a, spec.usage.requirements.rated_voltage_v
sha256 6782bf105cf4cc945142e65356bd7a21a9fc007b008ec3616307956030d72b31
Supports: offers
FAQ
RobStride 04 QDD Actuator questions
How much does the RobStride 04 QDD Actuator cost?
From $295 at www.roboticscenter.ai. Prices are observed unit prices before tax and shipping.
What are the RobStride 04 QDD Actuator dimensions?
120 × 120 × 52.2 mm. A STEP model is available for enclosure fit checks.
Where does this RobStride 04 QDD Actuator data come from?
Every value in this record is traced to a source — 2 documents including the board and chip datasheets — with the page and table cited per value. Unknowns are left explicit, never guessed.