Open-source robot · Apache-2.0
SO-101 robot arm
Six-axis desk robot arm made for teaching robots new skills. Its project publishes: printable parts, STEP files, parts list, assembly guide, and LeRobot software.
Independent open-source projects, not made by or affiliated with Infinomni.
Play it in your browser
Pose the arm or try a wave.
The real arm is usually driven by a second, hand-held leader arm, or by a policy trained on recorded demonstrations (LeRobot). Here there is no leader arm, no camera and no policy: it goes where its sliders put it.
Opens the arm in the playground, free and with no account. About 18 MB of model files download from jsDelivr.
Free print kit
23 printed pieces for one build, from 19 STL files (the extra files are alternatives and fit gauges). The files are the project’s own, unmodified and at their upstream paths, from TheRobotStudio/SO-ARM100 at 7629d2ad (The Robot Studio). The zip adds the licence, a NOTICE crediting the project, a README and SHA-256 sums.
2.2 MB · free, no account.
Parts list
This source inventory is frozen. Reviewed purchase links can be updated without changing the parts or quantities recorded here. The list is incomplete and does not verify printed fit, wiring, or physical operation.
One 7.4V C001 follower arm
| Part | Quantity |
|---|---|
| STS3215 Servo 7.4V, 1/345 gear (C001) | 6 |
| Motor Control Board | 1 |
| USB-C Cable 2 pcs | 2 |
| Power Supply | 1 |
| Table Clamp 2pcs | 2 |
| Screwdriver Set | 1 kit |
As the project lists it in README.md, captured 2026-10-03. See this list with reviewed buying links.
Follower and mixed-ratio leader arms
| Part | Quantity |
|---|---|
| STS3215 Servo 7.4V, 1/345 gear (C001) | 7 |
| STS3215 Servo 7.4V, 1/191 gear (C044) | 2 |
| STS3215 Servo 7.4V, 1/147 gear (C046) | 3 |
| Motor Control Board | 2 |
| USB-C Cable 2 pcs | 2 |
| Power Supply | 2 |
| Table Clamp 4pcs | 4 |
| Screwdriver Set | 1 kit |
As the project lists it in README.md, captured 2026-10-03. See this list with reviewed buying links.
Credits and licence
SO-101 by The Robot Studio; its simulation model by the MuJoCo Menagerie contributors. Licensed under the Apache License 2.0. The project’s files: TheRobotStudio/SO-ARM100.
The model in the simulator
MuJoCo Menagerie’s SO-101 model (robotstudio_so101), unmodified, at the playground’s pinned commit. Model source.
More open-source robots
- Open Duck Mini v2: Expressive little walking droid.
- LeKiwi: Three-wheel mobile robot with a printable arm.
- All of them in Infinomni’s robot list