#Quasi-direct drive (12)

The Complete Robot Joint Module Selection Guide: Harmonic, Planetary, RV, Cycloidal & Quasi-Direct Drive — Vendor Research and Configurations by Robot Weight Class

How should robot joint modules actually be selected? Drawing on 200+ joint-module/reducer entries in the RobotWorld knowledge base, product research on leading vendors (Harmonic Drive, Nabtesco, Leaderdrive, Laifual, Leadshine, EYOBOT, ZeroErr, JIECANG, CubeMars, ENCOS), and item-by-item verification of the supply chains behind Tesla, Unitree, UBTECH, AgiBot and Fourier, this guide systematically compares harmonic, planetary, RV, cycloidal and quasi-direct-drive (QDD) transmission routes on performance and cost, provides a torque-tier product cheat-sheet (0.5-200 N·m) and full configuration recipes by robot weight class (small <=25kg / mid 30-55kg / large 60-100kg), plus a practical pitfall-avoidance playbook.

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Joint modulesHarmonic reducersPlanetary reducersQuasi-direct driveHumanoid robots

RobStride EduLite 05 Quasi-Direct-Drive Joint Module

EduLite 05 entry-level quasi-direct-drive joint module for developers and education: 6N·m peak / 1.8N·m rated torque, 9:1 ratio, 242g, powder-metallurgy gears and dual magnetic encoders at just ￥299, ideal for teaching, research and DIY robots.

COMPONENT

Joint modulesIntegrated jointsQuasi-direct drivePlanetary reductionFOC

RobStride RobStride 06 Quasi-Direct-Drive Joint Module

RobStride 06 mid-torque quasi-direct-drive joint module: 36N·m peak / 11N·m rated torque, 9:1 ratio, 621g, 88×88×49mm. FOC drive, dual magnetic encoders and closed-loop thermal control, for humanoid elbow/knee and quadruped hip joints.

COMPONENT

Joint modulesIntegrated jointsQuasi-direct drivePlanetary reductionFOC

RobStride RobStride 05 Quasi-Direct-Drive Joint Module

RobStride 05 compact quasi-direct-drive joint module: 5.5N·m peak / 1.6N·m rated torque, 7.75:1 ratio, only 191g, 46×46×44mm. FOC drive with closed-loop thermal control, for humanoid wrist/ankle joints, small quadrupeds and exoskeletons.

COMPONENT

Joint modulesIntegrated jointsQuasi-direct drivePlanetary reductionFOC

RobStride RobStride 04 Quasi-Direct-Drive Joint Module

RobStride 04 flagship high-torque quasi-direct-drive joint module: 120N·m peak / 40N·m rated torque, 9:1 ratio, 1420g, torque density 85.71N·m/kg, 700W rated power, dual 14-bit magnetic encoders, CE certified. Ideal for humanoid hip/knee joints.

COMPONENT

Joint modulesIntegrated jointsQuasi-direct drivePlanetary reductionFOC

RobStride RobStride 03 Quasi-Direct-Drive Joint Module

RobStride 03 high-torque quasi-direct-drive joint module: 60N·m peak / 20N·m rated torque, 9:1 ratio, 880g, torque density 66.67N·m/kg, 380W rated power, dual magnetic encoders. Suited for humanoid shoulder/waist/hip joints.

COMPONENT

Joint modulesIntegrated jointsQuasi-direct drivePlanetary reductionFOC

RobStride RobStride 02 Quasi-Direct-Drive Joint Module

RobStride 02 dual-encoder quasi-direct-drive joint module: driver, motor, planetary reducer and dual magnetic encoders in one, 17N·m peak / 6N·m rated torque, 7.75:1 ratio, 405g. Dual encoders enable output-side absolute position closed-loop control for humanoid limbs and cobots.

COMPONENT

Joint modulesIntegrated jointsQuasi-direct drivePlanetary reductionFOC

RobStride RobStride 02 IP67 Quasi-Direct-Drive Joint Module

RobStride 02 IP67 quasi-direct-drive joint module with full dust/water protection: 17N·m peak / 6N·m rated torque, 7.75:1 ratio, 490g, 60×60×27mm, dual magnetic encoders. Built for outdoor quadrupeds and rugged deployments, 48V supply.

COMPONENT

Joint modulesIntegrated jointsQuasi-direct drivePlanetary reductionFOC

RobStride RobStride 01 Quasi-Direct-Drive Joint Module

RobStride 01 quasi-direct-drive joint module integrating driver, motor, planetary reducer and encoder: 17N·m peak / 6N·m rated torque, 7.75:1 ratio, 380g, torque density 44.73N·m/kg, 170W rated output, IP52 (IP67 customizable), with tuning software and dev examples.

COMPONENT

Joint modulesIntegrated jointsQuasi-direct drivePlanetary reductionFOC

RobStride RobStride 00 Quasi-Direct-Drive Joint Module

RobStride 00 quasi-direct-drive integrated joint module: motor + planetary reducer + driver in one, 14N·m peak / 5N·m rated torque, 10:1 ratio, only 310g, 57×57×51mm. FOC drive with dual magnetic encoders, 48V rated voltage, for quadruped/humanoid robot joints, robotic arms and exoskeletons.

COMPONENT

Joint modulesIntegrated jointsQuasi-direct drivePlanetary reductionFOC

PHYBOT PhyArc Quasi-Direct-Drive Integrated Cycloidal Joint Module Series

PHYBOT's new-generation PhyArc quasi-direct-drive integrated cycloidal joint modules come in six sizes (47/68/78/95/102/150) with in-house torque motors, cycloidal reduction and dual encoders in a hollow-shaft design; peak torque 12-590 N.m, peak torque density up to 244 N.m/kg, repeatability better than 1 arc-minute, and inertia+damping compensation surviving over 5x instantaneous overload impacts; shipped with SDK, interface board and dev kits for humanoid and other robotics scenarios.

COMPONENT

Joint modulesCycloidal reducersQuasi-direct driveIntegrated jointsDongyi Technology

Humanoid

PNDbotics Adam Humanoid Robot

Bionik

HumanoidBionik