---
title: "Robots and the actuators inside them"
description: "Which motor sits in each joint of real robot arms and legged robots, linked to actuator specs."
canonical: https://actuatorlist.com/robots
last-updated: 2026-11-01T14:05:43.000Z
---
# Robots and the actuators inside them

22 robots with the motor used in each joint, linked to the actuator spec sheet where the catalog has one. Use it to see which parts real builds rely on.

## Asimov 1 by Menlo Research

Open-source 1.2 m, 35 kg biped humanoid for whole-body control and locomotion research, sold as a DIY kit with full BOM, CAD and a MuJoCo sim on GitHub. Rated for 5 kg per arm.

- Brand: Menlo Research (Singapore)
- Type: Humanoid
- Degrees of freedom: 25
- Payload: 5 kg
- Height: 1.20 m
- Weight: 35 kg
- Price: $15,000 to $20,000
- Runtime: not published (Hot-swap 13S4P Li-ion pack)
- Actuators: bought off the shelf
- Published: CAD, URDF, SDK source, BOM
- Availability: pre-order (Batch 4 forming, $499 deposit)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Hip pitch + waist yaw | 3 | [ENCOS EC-A6416-P2-25](https://actuatorlist.com/actuators/encos-ec-a6416-p2-25) | 120 Nm |
| Hip roll + shoulder pitch | 4 | [ENCOS EC-A5013-H17-100](https://actuatorlist.com/actuators/encos-ec-a5013-h17-100) | 90 Nm |
| Hip yaw + shoulder yaw | 4 | [ENCOS EC-A3814-H14-107](https://actuatorlist.com/actuators/encos-ec-a3814-h14-107) | 60 Nm |
| Knee + shoulder roll | 4 | [ENCOS EC-A4315-P2-36](https://actuatorlist.com/actuators/encos-ec-a4315-p2-36) | 75 Nm |
| Ankle (parallel), elbow, wrist yaw, neck | 10 | [ENCOS EC-A4310-P2-36](https://actuatorlist.com/actuators/encos-ec-a4310-p2-36) | 36 Nm |

## G1 by Unitree Robotics

Compact 1.32 m, 35 kg humanoid with 23 joints (23 to 43 on the EDU version) driven by low-inertia internal-rotor PMSM joint motors. Unitree's spec sheet quotes a 90 N·m knee peak; its published URDF sets the knee and hip-roll limit at 139 N·m, which the joint map uses. About 2 hours of battery life.

- Brand: Unitree Robotics (China)
- Type: Humanoid
- Degrees of freedom: 23
- Payload: 2 kg
- Height: 1.32 m
- Arm reach: 450 mm
- Weight: 35 kg
- Price: $13,500 to $21,500
- Runtime: 2 h
- Actuators: designed in-house
- Published: CAD, URDF, SDK source
- Availability: shipping

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Hip pitch + hip yaw + waist yaw | 5 | Unitree Unitree N7520-14.3 | 88 Nm |
| Hip roll + knee | 4 | Unitree Unitree N7520-22.5 | 139 Nm |
| Shoulder, elbow, wrist roll | 10 | Unitree Unitree N5020-16 | 25 Nm |
| Ankle pitch + roll (parallel linkage) | 4 | Unitree Unitree N5020-16 | 25 Nm |

## H2 by Unitree Robotics

Full-size 1.82 m, 70 kg humanoid with 31 DOF, up to 360 N·m at the leg joints and a bionic head. Arms carry about 7 kg rated, 15 kg peak.

- Brand: Unitree Robotics (China)
- Type: Humanoid
- Degrees of freedom: 31
- Payload: 7 kg
- Height: 1.82 m
- Arm reach: 690 mm
- Weight: 70 kg
- Price: $29,900
- Runtime: 3 h
- Actuators: designed in-house
- Published: URDF, SDK source
- Availability: pre-order (Retailers quote phased 2026 deliveries)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Legs | 12 | Unitree H2 leg joint motor | 360 Nm |
| Arms | 14 | Unitree H2 arm joint motor | 120 Nm |

## NEO by 1X Technologies

Home humanoid with tendon-driven actuation, a soft lattice-polymer body and 22-DOF hands. Weighs 30 kg and carries 25 kg.

- Brand: 1X Technologies (United States)
- Type: Humanoid
- Degrees of freedom: 75
- Payload: 25 kg (whole body)
- Height: 1.68 m
- Weight: 30 kg
- Price: $20,000
- Runtime: 4 h
- Actuators: designed in-house
- Published: none
- Availability: pre-order ($200 deposit, US deliveries 2026)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Legs | 12 | 1X Technologies NEO body tendon drive | n/a |
| Spine | 2 | 1X Technologies NEO body tendon drive | n/a |
| Neck | 3 | 1X Technologies NEO body tendon drive | n/a |
| Shoulder + elbow | 8 | 1X Technologies NEO body tendon drive | n/a |
| Wrist | 6 | 1X Technologies NEO wrist tendon drive | 17.8 Nm |
| Hands (fingers + palm) | 44 | 1X Technologies NEO hand tendon drive | n/a |

## T1 by Booster Robotics

Developer humanoid, 1.18 m and about 30 kg, with 23 DOF (31 with grippers, 41 with dexterous hands) and up to 130 N·m peak joint torque. Won RoboCup 2025 AdultSize. Joint-map torques are the effort limits in Booster's published URDF, which does not name the motor models.

- Brand: Booster Robotics (China)
- Type: Humanoid
- Degrees of freedom: 23
- Payload: n/a
- Height: 1.18 m
- Arm reach: 450 mm
- Weight: 30 kg
- Price: $29,800 to $49,000
- Runtime: 2 h (About 2 h walking, 4 h standing; retailer figure)
- Published: URDF
- Availability: discontinued (Replaced by the T2)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Head (yaw, pitch) | 2 | Booster Robotics T1 head joint motor | 7 Nm |
| Shoulder + elbow | 8 | Booster Robotics T1 arm joint motor | 38.3 Nm |
| Waist yaw + hip roll + hip yaw | 5 | Booster Robotics T1 hip roll/yaw and waist joint motor | 68 Nm |
| Hip pitch | 2 | Booster Robotics T1 hip pitch joint motor | 98.8 Nm |
| Knee | 2 | Booster Robotics T1 knee joint motor | 130.5 Nm |
| Ankle pitch | 2 | Booster Robotics T1 ankle pitch joint motor | 73.1 Nm |
| Ankle roll | 2 | Booster Robotics T1 ankle roll joint motor | 17.2 Nm |

## K1 by Booster Robotics

Entry-level 95 cm, 19.5 kg humanoid with 22 DOF, sold in Geek, Education and Professional editions. Won RoboCup 2025 KidSize. Booster's product page quotes up to 60 N·m peak joint torque, but its published URDF sets higher effort limits (knee 112 N·m, hip pitch 68 N·m); the joint map uses the URDF limits, which do not name the motor models.

- Brand: Booster Robotics (China)
- Type: Humanoid
- Degrees of freedom: 22
- Payload: n/a
- Height: 0.95 m
- Weight: 19.50 kg
- Price: $4,999
- Runtime: 1.17 h (1 h 10 min on Edu and Pro; 20 min on the Geek edition)
- Actuators: designed in-house
- Published: URDF, SDK source
- Availability: shipping (Through distributors; direct by inquiry)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Head (yaw, pitch) | 2 | Booster Robotics K1 head joint motor | 6 Nm |
| Shoulder + elbow | 8 | Booster Robotics K1 arm joint motor | 14 Nm |
| Hip pitch | 2 | Booster Robotics K1 hip pitch joint motor | 68 Nm |
| Hip roll | 2 | Booster Robotics K1 hip roll joint motor | 43 Nm |
| Hip yaw + ankle pitch + ankle roll | 6 | Booster Robotics K1 hip yaw and ankle joint motor | 38.3 Nm |
| Knee | 2 | Booster Robotics K1 knee joint motor | 112 Nm |

## Reachy 2 by Pollen Robotics

Open-source bimanual humanoid on an omnidirectional base, height adjustable from 1.36 to 1.66 m. Two 7-DOF arms carry about 3 kg each and a 3-DOF neck aims the head, all driven by Pollen's own Orbita parallel joints: 2-axis units at shoulder and elbow, 3-axis units at wrist and neck. Pollen publishes no list price; about $70k is the figure reported at launch.

- Brand: Pollen Robotics (France)
- Type: Humanoid
- Degrees of freedom: 17
- Payload: 3 kg
- Height: 1.66 m
- Weight: 50 kg
- Price: $70,000
- Runtime: 8 h
- Actuators: designed in-house
- Published: URDF, SDK source
- Availability: quote only

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Shoulder + elbow (2 axes each) | 4 | Pollen Robotics Orbita 2D | 16.5 Nm |
| Wrist + neck (3 axes each) | 3 | Pollen Robotics Orbita 3D | 15 Nm |

## Reachy Mini by Pollen Robotics

Open-source desktop companion robot from Pollen and Hugging Face, sold as a kit. A Stewart platform of six servos gives the head 6 DOF, with body rotation and two antennas on top. $399 Lite runs from a computer over USB; $499 Wireless adds a Raspberry Pi CM4 and battery.

- Brand: Pollen Robotics (France)
- Type: Humanoid
- Degrees of freedom: 9
- Payload: n/a
- Height: 0.28 m
- Weight: 1.50 kg
- Price: $399 to $499
- Runtime: 4 h (Wireless has a 12.8 Wh pack rated 2 to 4 h depending on use; Lite runs on USB power)
- Actuators: bought off the shelf
- Published: URDF, SDK source
- Availability: shipping (Up to 90 days)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Head (Stewart platform, 6 DOF) | 6 | [Robotis (Dynamixel) XL330-M288-T](https://actuatorlist.com/actuators/dynamixel-xl330-m288-t) | 0.5 Nm |
| Body rotation | 1 | Robotis (Dynamixel) XC330-M288 (custom) | 0.9 Nm |
| Antennas | 2 | [Robotis (Dynamixel) XL330-M077-T](https://actuatorlist.com/actuators/dynamixel-xl330-m077-t) | 0.2 Nm |

## Manmaru YOR by ManmaruAI

Semi-humanoid for Physical AI research: two Seeed reBot Arm B601-DM arms (6 axes + gripper each, 767 mm reach, 1.5 kg payload) on the open-source YOR four-module swerve base. About $6,300 in parts to build from the published BOM and URDF, or about $12,700 assembled and tested. Seeed's BOM lists the Damiao motor mix per arm but not which joint gets which.

- Brand: ManmaruAI (Japan)
- Type: Humanoid
- Degrees of freedom: 14
- Payload: 1.5 kg
- Height: 0.84 m
- Arm reach: 767 mm
- Weight: n/a
- Price: $6,300 to $12,700
- Runtime: not published
- Actuators: bought off the shelf
- Published: URDF, BOM
- Availability: quote only (Assembled by quote; DIY from the public BOM)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Arm joints, higher torque (3 per arm) | 6 | [Damiao (DMBots) Damiao DM-J4340P-2EC](https://actuatorlist.com/actuators/damiao-dm-j4340p-2ec) | 27 Nm |
| Arm joints + gripper (4 per arm) | 8 | [Damiao (DMBots) Damiao DM-J4310-2EC](https://actuatorlist.com/actuators/damiao-dm-j4310-2ec) | 7 Nm |

## R1 by Unitree Robotics

Unitree R1 is a 1.23 m, roughly 29 kg entry-level humanoid sold from $4,900 (R1 AIR, 20 DOF) and $5,900 (R1, 26 DOF), with an R1 EDU edition of 26 to 40 DOF sold through sales. Joints use Unitree's own low-inertia internal-rotor PMSM actuators with crossed roller bearings and dual encoders. Unitree publishes R1 URDF models in unitree\_ros and R1 examples in the open unitree\_sdk2.

- Brand: Unitree Robotics (China)
- Type: Humanoid
- Degrees of freedom: 26
- Payload: 2 kg
- Height: 1.23 m
- Arm reach: 420 mm
- Weight: 29 kg
- Price: $5,900
- Runtime: 1 h (About 1 h per charge on all editions (R1 AIR, R1, R1 EDU); quick-release smart battery.)
- Actuators: designed in-house
- Published: URDF, SDK source
- Availability: shipping

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Hip pitch + roll + yaw | 6 | Unitree R1 60 N·m joint | 60 Nm |
| Knee | 2 | Unitree R1 60 N·m joint | 60 Nm |
| Ankle pitch + roll (linkage) | 4 | Unitree R1 ankle joint | 50 Nm |
| Waist roll + yaw | 2 | Unitree R1 60 N·m joint | 60 Nm |
| Shoulder pitch + roll | 4 | Unitree R1 60 N·m joint | 60 Nm |
| Shoulder yaw + elbow + wrist roll | 6 | Unitree R1 33 N·m joint | 33 Nm |
| Head pitch | 1 | Unitree R1 33 N·m joint | 33 Nm |
| Head yaw | 1 | Unitree R1 head yaw servo | 0.9 Nm |

## GR-3 by Fourier

Fourier GR-3 is a 165 cm, 71 kg care and companionship humanoid unveiled in August 2025, with a soft upholstered shell, 31 touch sensors, a four-microphone array and an LLM-driven interaction stack. It offers up to 55 DOF with optional 12-DoF dexterous hands, a 3 kg single-arm load, a 440 Nm maximum joint peak torque and about 3 hours of runtime. It is built on Fourier's own actuators and sold in GR-3, GR-3C and GR-3C Ultra configurations on quote.

- Brand: Fourier (China)
- Type: Humanoid
- Degrees of freedom: 55
- Payload: 3 kg
- Height: 1.65 m
- Weight: 71 kg
- Price: quote only
- Runtime: 3 h (Hot-swappable packs (702 Wh + 234 Wh); 55 DOF counts the optional 12-DoF hands, 43 with the basic hands)
- Actuators: designed in-house
- Published: none
- Availability: quote only

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Legs | 12 | Fourier GR-3 leg actuator | n/a |
| Waist | 3 | Fourier GR-3 upper-body actuator | n/a |
| Arms | 14 | Fourier GR-3 upper-body actuator | n/a |
| Neck | 2 | Fourier GR-3 upper-body actuator | n/a |
| Dexterous hands (optional) | 24 | Fourier GR-3 hand joint | n/a |

## Digit 5 by Agility Robotics

Digit 5 is Agility Robotics' fifth generation bipedal humanoid, unveiled September 15, 2026, for warehouse and manufacturing work alongside people without safety fencing. It stands 1.81 m, weighs 129 kg, lifts up to 22.7 kg (50 lb) repeatedly and reaches up to 2.2 m, with forward-facing legs driven by proprietary cycloidal actuators. A 90 minute battery recharges in 9 minutes, and the robot is sold by quote or as Robots-as-a-Service, with early access in H1 2027.

- Brand: Agility Robotics (United States)
- Type: Humanoid
- Degrees of freedom: n/a
- Payload: 22.7 kg (whole body)
- Height: 1.81 m
- Weight: 129 kg
- Price: quote only
- Runtime: 1.5 h (10:1 run-to-charge with a 9 min autonomous charge; no list price, reported S-4 terms are about $200k outright or $8,500/month RaaS)
- Actuators: designed in-house
- Published: none
- Availability: quote only (Early access expected H1 2027; general availability expected by end of 2027 (US, Canada, then EU and UK))

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Knee (rest of joint map unpublished) | 2 | Agility Robotics Digit 5 knee cycloidal actuator | n/a |

## YAM by i2RT Robotics

Low-cost 6-DOF manipulator built for imitation learning and teleoperation data collection. CNC 6061 billet frame, integrated cross-roller bearings, 95 mm patent-pending gripper.

- Brand: i2RT Robotics (China)
- Degrees of freedom: 6
- Payload: 2 kg
- Reach: 750 mm
- Weight: 5.02 kg
- Price: $2,999
- Runtime: mains-powered
- Actuators: bought off the shelf
- Published: URDF, SDK source
- Availability: shipping (20 business days)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Shoulder (J1-J3) | 3 | [Damiao (DMBots) Damiao DM-J4340-2EC](https://actuatorlist.com/actuators/damiao-dm-j4340-2ec) | 27 Nm |
| Elbow + wrist (J4-J6) | 3 | [Damiao (DMBots) Damiao DM-J4310-2EC](https://actuatorlist.com/actuators/damiao-dm-j4310-2ec) | 7 Nm |

## YAM Pro by i2RT Robotics

Same motor set and SDK as the base YAM; the control-law difference is a stiffer J4 position gain plus build refinements. Interchangeable with Standard and Ultra in the SDK.

- Brand: i2RT Robotics (China)
- Degrees of freedom: 6
- Payload: 3 kg
- Reach: 750 mm
- Weight: 5.06 kg
- Price: $3,499
- Runtime: mains-powered
- Actuators: bought off the shelf
- Published: URDF, SDK source
- Availability: shipping (20 business days)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Shoulder (J1-J3) | 3 | [Damiao (DMBots) Damiao DM-J4340-2EC](https://actuatorlist.com/actuators/damiao-dm-j4340-2ec) | 27 Nm |
| Elbow + wrist (J4-J6) | 3 | [Damiao (DMBots) Damiao DM-J4310-2EC](https://actuatorlist.com/actuators/damiao-dm-j4310-2ec) | 7 Nm |

## YAM Ultra 2 by i2RT Robotics

Enhanced build of the 6-DOF YAM with the same Damiao motor chain and SDK as Standard and Pro, tuned for higher-duty data collection.

- Brand: i2RT Robotics (China)
- Degrees of freedom: 6
- Payload: 4 kg
- Reach: 750 mm
- Weight: 5.30 kg
- Price: $4,299 to $4,399
- Runtime: mains-powered
- Actuators: bought off the shelf
- Published: URDF, SDK source
- Availability: shipping (20 business days)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Shoulder (J1-J3) | 3 | [Damiao (DMBots) Damiao DM-J4340-2EC](https://actuatorlist.com/actuators/damiao-dm-j4340-2ec) | 27 Nm |
| Elbow + wrist (J4-J6) | 3 | [Damiao (DMBots) Damiao DM-J4310-2EC](https://actuatorlist.com/actuators/damiao-dm-j4310-2ec) | 7 Nm |

## BIG YAM by i2RT Robotics

Heavier-payload 6-DOF variant. Uses DM6248 motors at the shoulders with substantially different control gains and a reversed joint 2; the only YAM whose SDK gains differ meaningfully from Standard.

- Brand: i2RT Robotics (China)
- Degrees of freedom: 6
- Payload: 4 kg
- Reach: 1100 mm
- Weight: 6.40 kg
- Price: $4,999
- Runtime: mains-powered
- Actuators: bought off the shelf
- Published: CAD, URDF, SDK source
- Availability: shipping (About 3 weeks)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Shoulder (J1-J2) | 2 | [Damiao (DMBots) Damiao DM-J6248-2EC](https://actuatorlist.com/actuators/damiao-dm-j6248p-2ec) | 97 Nm |
| Upper arm (J3-J4) | 2 | [Damiao (DMBots) Damiao DM-J4340-2EC](https://actuatorlist.com/actuators/damiao-dm-j4340-2ec) | 27 Nm |
| Wrist (J5-J6) | 2 | [Damiao (DMBots) Damiao DM-J4310-2EC](https://actuatorlist.com/actuators/damiao-dm-j4310-2ec) | 7 Nm |

## YAM 7 by i2RT Robotics

7-DOF member of the YAM family with an added redundant joint for richer wrist orientation. Unlike the rest of the family it runs on i2RT's own GF-series actuators rather than Damiao motors: GF62X48-10 at J1-J2, GF43X40-16 at J3-J4, GF43X40-10 at J5 and GF43X10-10 at J6-J7 and the gripper.

- Brand: i2RT Robotics (China)
- Degrees of freedom: 7
- Payload: 4 kg
- Reach: 803 mm
- Weight: 6.64 kg
- Price: $4,999 to $9,999
- Runtime: mains-powered
- Actuators: designed in-house
- Published: none
- Availability: shipping (About 30 days)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Shoulder (J1-J2) | 2 | i2RT Robotics GF62X48-10 | 95 Nm |
| Upper arm (J3-J4) | 2 | i2RT Robotics GF43X40-16 | 28 Nm |
| Forearm (J5) | 1 | i2RT Robotics GF43X40-10 | 23.5 Nm |
| Wrist (J6-J7) | 2 | i2RT Robotics GF43X10-10 | 7 Nm |

## YAM Leader by i2RT Robotics

Teleoperation leader arm: the operator backdrives it to puppeteer a follower YAM (GELLO-style). The SDK's leader mode drives a standard YAM arm config by default (DM4340 at J1-J3, DM4310 at J4-J6) with a teaching handle in place of the gripper.

- Brand: i2RT Robotics (China)
- Degrees of freedom: 6
- Payload: n/a
- Reach: n/a
- Weight: 4.60 kg
- Price: $2,999
- Runtime: mains-powered
- Actuators: bought off the shelf
- Published: URDF, SDK source
- Availability: shipping (20 business days)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Shoulder (J1-J3) | 3 | [Damiao (DMBots) Damiao DM-J4340-2EC](https://actuatorlist.com/actuators/damiao-dm-j4340-2ec) | 27 Nm |
| Elbow + wrist (J4-J6) | 3 | [Damiao (DMBots) Damiao DM-J4310-2EC](https://actuatorlist.com/actuators/damiao-dm-j4310-2ec) | 7 Nm |

## PiPER by AgileX Robotics

PiPER is a 4.2 kg desktop 6-DOF arm from AgileX Robotics with a 1.5 kg payload, 626 mm reach and ±0.1 mm repeatability, built on an aluminum alloy frame with an integrated controller. It runs on DC 24V and is controlled over CAN, with drag teaching, trajectory replay, an open-source Python SDK, ROS 1/ROS 2 drivers and URDF models for Gazebo and Isaac Sim. A two-finger gripper (0 to 70 mm stroke, 40 N rated clamping force) and a teach pendant are optional end effectors.

- Brand: AgileX Robotics (China)
- Degrees of freedom: 6
- Payload: 1.5 kg
- Reach: 626 mm
- Weight: 4.20 kg
- Price: $3,500
- Runtime: mains-powered
- Published: URDF, SDK source
- Availability: shipping

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Arm joints J1-J6 | 6 | AgileX Robotics PiPER joint module | n/a |

## SO-101 by TheRobotStudio

SO-101 is an open-source, 3D-printable arm designed by TheRobotStudio with Hugging Face as the successor to SO-100, with improved wiring and easier assembly. The follower arm uses six Feetech STS3215 serial bus servos (5 arm joints plus a gripper) at a 1:345 gear ratio and is usually paired with a leader arm for teleoperation and imitation learning in the LeRobot library. STEP and STL files, simulation models and a full bill of materials are published under Apache-2.0, and kits are sold by Seeed Studio, WowRobo, PartaBot and others.

- Brand: TheRobotStudio
- Degrees of freedom: 6
- Payload: n/a
- Reach: n/a
- Weight: n/a
- Price: $121.94 to $315.99
- Runtime: mains-powered
- Actuators: bought off the shelf
- Published: CAD, URDF, SDK source, BOM
- Availability: shipping

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Arm joints | 5 | [Feetech STS3215 C001 (7.4V, 1:345)](https://actuatorlist.com/actuators/feetech-sts3215-c001) | 1.9 Nm |
| Gripper | 1 | [Feetech STS3215 C001 (7.4V, 1:345)](https://actuatorlist.com/actuators/feetech-sts3215-c001) | 1.9 Nm |

## Stretch 3 by Hello Robot

Lightweight mobile manipulator: a 24.5 kg, 33 x 34 cm differential-drive base carries a 1.41 m mast with a lift, a telescoping arm reaching 0.52 m and a yaw-pitch-roll wrist, 7 manipulation DOF plus a compliant gripper and a pan-tilt head camera. Base wheels, lift and arm run on closed-loop steppers whose model Hello Robot does not name; wrist, gripper and head use Dynamixel servos. Listed at $24,950 until Stretch 4 took over in 2026.

- Brand: Hello Robot (United States)
- Degrees of freedom: 7
- Payload: 2 kg
- Reach: 520 mm
- Weight: 24.50 kg
- Price: $24,950
- Runtime: 5 h (2 to 5 h per charge: 5 h at light CPU load, 2 h at high CPU load)
- Actuators: bought off the shelf
- Published: URDF, SDK source
- Availability: discontinued (Replaced by Stretch 4)

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Base drive wheels | 2 | Hello Robot Stretch closed-loop stepper | n/a |
| Lift + telescoping arm | 2 | Hello Robot Stretch closed-loop stepper | n/a |
| Wrist yaw + head tilt | 2 | [Robotis (Dynamixel) XC430-W240-T](https://actuatorlist.com/actuators/dynamixel-xc430-w240-t) | 1.9 Nm |
| Wrist pitch | 1 | [Robotis (Dynamixel) XM540-W270-T](https://actuatorlist.com/actuators/dynamixel-xm540-w270-t) | 10.6 Nm |
| Wrist roll | 1 | [Robotis (Dynamixel) XM430-W350-T](https://actuatorlist.com/actuators/dynamixel-xm430-w350-t) | 4.1 Nm |
| Gripper + head pan | 2 | [Robotis (Dynamixel) XL430-W250-T](https://actuatorlist.com/actuators/dynamixel-xl430-w250-t) | 1.5 Nm |

## Franka Research 3 by Franka Robotics

FR3 is the 7-DOF, force-sensitive research arm from Franka Robotics, with a link-side torque sensor in every joint, 3 kg payload, 855 mm reach and under ±0.1 mm repeatability. The open-source libfranka and Franka Control Interface give 1 kHz joint torque, position and velocity control, with ROS 2 and MATLAB support. Joint torque limits from the datasheet are listed below; Franka does not name its motors. Franka sells on quote; the price is Vention's catalog listing.

- Brand: Franka Robotics (Germany)
- Degrees of freedom: 7
- Payload: 3 kg
- Reach: 855 mm
- Weight: 18.30 kg
- Price: $29,218.06
- Runtime: mains-powered
- Published: URDF, SDK source
- Availability: quote only

| Joint | Count | Motor | Peak torque |
| --- | --- | --- | --- |
| Shoulder + elbow (A1-A4) | 4 | Franka Robotics FR3 joint drive A1-A4 | 87 Nm |
| Wrist (A5-A7) | 3 | Franka Robotics FR3 joint drive A5-A7 | 12 Nm |