RobotEra STAR1 (3.6 m/s, 55-DoF + 12-DoF XHAND 1) & Kepler Forerunner K2 (8,000N Roller-Screw, 30kg Payload) Actuator Breakdown
Comparative humanoid engineering analysis of the RobotEra STAR1 (171cm, 65kg, 400 N·m rotary joints, 3.6 m/s outdoor sprint, and tendon-free 12-DoF XHAND 1) and the $30,000 Kepler Forerunner K2 (175cm, 75kg, 8,000N planetary roller-screw linear actuators and 30kg dual-arm payload).
⚡ Key Engineering & Supply-Chain Takeaways
- RobotEra STAR1 (171cm, 65kg, 55 DoF) combines 400 N·m peak-torque modular rotary actuators with 550 TOPS of onboard AI compute to sustain a documented 3.6 m/s (12.96 km/h) outdoor bipedal running speed.
- STAR1's dual XHAND 1 dexterous hands implement 12 fully independent direct-drive DoF (110N grip force) via internal gear linkages, eliminating cable/tendon creep.
- Kepler Forerunner K2 ($30,000, 175cm, 75kg, 52 DoF) uses custom 8,000N planetary roller-screw linear actuators to lift 15kg per arm (30kg combined) across 8-hour factory shifts.
🔬 Technical & Supply-Chain Specification Matrix
| RobotEra STAR1 ($55,000) | 171cm / 65.0kg / 55 DoF / 400 N·m Peak Torque / 3.6 m/s Outdoor Running Speed |
|---|---|
| STAR1 Hands & AI Compute | Dual 12-DoF Direct-Drive XHAND 1 (110N Grip) + 550 TOPS Onboard VLA Compute |
| Kepler Forerunner K2 ($30,000) | 175cm / 75.0kg / 52 DoF / 8,000N Planetary Roller-Screw Linear Actuators |
| Kepler K2 Payload & Shift Life | 15.0kg Single-Arm (30.0kg Dual-Arm) Payload + 11-DoF Tactile Hands + 8h Shift |
High-Speed Rotary Direct-Drive vs Planetary Roller-Screw Linear Actuation
Official specifications from RobotEra and Kepler Robotics highlight two distinct actuator topologies for full-size bipedal humanoids:
- RobotEra STAR1 (171cm, 65kg, 55 DoF): Uses 400 N·m rotary actuators and 550 TOPS of RL compute to reach 3.6 m/s outdoors while equipping dual 12-DoF direct-drive XHAND 1 hands.
- Kepler Forerunner K2 ($30,000, 175cm, 75kg, 52 DoF): Employs 8,000N planetary roller-screw linear actuators and 11-DoF 25-point tactile hands to lift 30kg bimanually over 8-hour industrial shifts.
🔗 Related AI Hardware in RECIWO Database
All 93 Devices →RobotEra STAR1 55-DoF High-Speed Bipedal Humanoid Robot
Full-size 171cm, 65kg general-purpose bipedal humanoid featuring 55 total Degrees of Freedom, 400 N·m peak joint torque actuators, 550 TOPS onboard AI compute, a documented 3.6 m/s outdoor running speed, and dual 12-DoF fully direct-driven XHAND 1 dexterous hands.
Kepler Forerunner K2 ("Bumblebee") 30kg-Payload Industrial Humanoid
Heavy-duty 175cm, 75kg industrial humanoid engineered with 52 Degrees of Freedom, proprietary 8,000N planetary roller-screw linear actuators, dual 11-DoF tactile dexterous hands (25 sensing points per fingertip), 30kg combined dual-arm payload, and 8-hour factory shift endurance.
Dobot Atom Straight-Knee Bimanual Humanoid Robot (ROM-1 VLA)
153cm, 62kg industrial and service humanoid featuring Dobot's Anthropomorphic Straight-Knee Walking System (42% lower gait energy consumption), ±0.05mm precision 7-DoF arms, 6-DoF dexterous hands, and 1,500 TOPS of ROM-1 VLA edge compute.
Unitree G1 Humanoid Robot (2026 Developer Edition)
Features 23 to 43 high-torque joint degrees of freedom, 3D LiDAR + depth vision perception, and end-to-end reinforcement learning & VLA manipulation policies.
📚 Related Deep-Dive Engineering Teardowns
Browse All 113 Articles →RobotEra STAR1 vs Kepler Forerunner K2 vs Unitree G1 Comparison: 3.6 m/s 55-DoF Biped vs 30kg Planetary Roller-Screw Humanoid
A technical specification and actuator architecture comparison of the RobotEra STAR1 ($55,000, 171cm 55-DoF bipedal humanoid with 3.6 m/s running speed, 400 N·m peak joint torque, and 12-DoF direct-drive XHAND 1), Kepler Forerunner K2 ($30,000, 175cm 52-DoF industrial humanoid with 8,000N planetary roller-screw linear actuators and 30kg dual-arm payload), and Dobot Atom ($27,500).
Dobot Atom vs Galbot G1 vs Unitree G1 Architecture Comparison: 42% Lower-Power Straight-Knee Gait vs Omnidirectional Wheeled VLA
A technical specification and kinematic comparison of the Dobot Atom ($27,500, 153cm straight-knee bipedal humanoid with ±0.05mm arm repeatability and 1,500 TOPS ROM-1 VLA compute), Galbot G1 ($38,000, 360-degree omnidirectional wheeled humanoid with 2.2m vertical reach and 12-DoF GraspVLA hands), and Unitree G1 ($16,000).
2026 Dexterous Robotic Hands Teardown: Tendon-Driven vs. Direct-Linkage & Tactile Array Skins
RECIWO Labs tested 6-DoF to 22-DoF anthropomorphic robotic hands across payload durability, Fingertip 3-axis Hall/piezoresistive tactile resolution, and VLA teleoperation reliability.
