Sources
SO-ARM100 — Open-Source Robot Arm
2026-09-10T00:00:00Z
2026-09-10T00:00:00Z
robotics
robot-arm
open-source
3d-print
lerobot
SO-ARM100 — Standard Open Arm 100
An open-source 6-axis robot arm designed to work with Hugging Face's LeRobot framework. 3D-printable, uses standard hobby servos, costs about $100 to build yourself.
Specs
| Spec | Value |
|---|---|
| Axes | 6 (shoulder, elbow, wrist roll/pitch/yaw, gripper) |
| Reach | ~400mm |
| Actuators | Standard hobby servos (LD-1501MG or similar) |
| Control | USB/serial servo controller |
| Frame | 3D printed (PLA/PETG) — STL files on GitHub |
| Weight | ~1.5-2 kg |
| Software | LeRobot (Python, PyTorch) |
What you need to build one
- 3D printer — print the STL files from TheRobotStudio/SO-ARM100
- 6x hobby servos (LD-1501MG or equivalent, ~$8-12 each)
- Servo controller board (USB interface, ~$15-25)
- Power supply (5-6V for servos)
- Fasteners (M3 screws, nuts, standoffs)
- Optional: 3D printed parts can be ordered from AliExpress/Seeed Studio for ~$35
Build cost breakdown
| Item | Cost |
|---|---|
| 3D printed parts (DIY print) | ~$5 filament |
| 3D printed parts (ordered) | ~$35 |
| 6x LD-1501MG servos | ~$60 |
| Servo controller | ~$20 |
| Power supply + hardware | ~$15 |
| Total DIY | ~$100 |
| Total with printed parts ordered | ~$130 |
LeRobot integration
- Plug-and-play with LeRobot's unified Robot class interface
- Dual-arm teleoperation: build two (leader + follower) for data collection
- Train imitation learning policies (ACT, Diffusion) on collected demonstrations
- Deploy trained policy back to the arm
- Entire pipeline from one GitHub repo
Resources
- GitHub: STL files, BOM, build guide
- LeRobot docs — Install, collect, train, deploy
- Optional hardware: raised leader base, camera mounts, different grippers
Related
- SO-ARM101 — newer version with improved wiring, easier assembly
- LeRobot Framework — the software framework that runs these arms