Robstride 01
The part that made cheap humanoids possible. A BLDC with a low-ratio planetary reducer and an integrated FOC driver speaking CAN, priced like a hobby servo and behaving like a robot joint.
The role it plays
An actuator turns electrical power into motion. The useful unit is never the motor alone — it is motor + reduction + encoder + driver loop, and most of the engineering is in the last three. The number that decides a design is continuous torque at the joint, not the peak figure on the datasheet. Peaks last milliseconds; gravity lasts all day.
Typical use: Quadruped legs, humanoid hips/knees, direct-drive arms.
What the numbers actually mean
The headline figure is 14 N·m (peak torque), with ~5 N·m continuous as the next most load-bearing number (rated torque). At $130 in the actuators tier it sits in the mid range: enough money that you should plan the mounting and wiring before ordering, but not so much that one mistake ends the project.
How it compares
Same subsystem, closest alternatives. The primary spec column is usually the one that decides it.
| Part | Price | Primary spec | Second spec |
|---|---|---|---|
| Robstride 01Quasi-direct-drive | $130 | 14 N·m | ~5 N·m continuous |
| Feetech STS3215Serial-bus servo | $17 | 30 kg·cm (2.94 N·m) @ 7.4 V | ~0.222 s / 60° |
| Feetech SCS0009Micro serial servo | $8 | 9 kg·cm (0.88 N·m) @ 6 V | ~0.1 s / 60° |
| Dynamixel XL430-W250-TSmart servo | $50 | 1.5 N·m @ 12 V | 59 rpm @ 12 V |
| Dynamixel XM430-W350-TSmart servo | $260 | 4.1 N·m @ 12 V | 46 rpm @ 12 V |
Where it shows up
Platforms in this atlas that use something in this class: Unitree Go2, Unitree G1, Boston Dynamics Spot.