A low-cost mobile manipulator that mounts an SO-101 arm on a three-wheel omni-drive base with stacked 3D-printed plates. It runs on a Raspberry Pi 5 and is controlled through Hugging Face's LeRobot software for teleoperation and imitation-learning data collection. It was developed by SIGRobotics at UIUC with Hugging Face.
At a glance
| Parts cost | $480 project · Stated by the project for the full 12V robot including the arm, excluding 3D printing. The base alone is about $250 source ↗ |
|---|---|
| Difficulty | 2/5 Easy · Printed parts and plug-in servo boards with no soldering, but LeRobot setup and calibration take some Python familiarity. |
| Build time | About 34 hours of printing plus about 2 hours of assembly (assumes the SO-101 arm is already built) source ↗ |
| Tools needed | 3D printer (about 34 h of PLA, some parts need supports), screwdrivers, table clamps, no soldering |
| Motors | Feetech STS3215 12V serial bus servos (3 for omni wheels, 6 per arm); Dynamixel XL430 variant available |
| Controller | Raspberry Pi 5 + Waveshare serial servo driver board; laptop for teleop/training |
| Sensors | 2 USB RGB cameras (front and wrist) |
| Published | ✓ Parts list✓ CAD/STL✓ Assembly guide✓ Wiring✓ Software✗ Video GitHub markdown (parts list, 3D printing, assembly) + Fusion 360 web CAD + Hugging Face LeRobot docs + Discord |
| Activity | Last update 2026-08-05 · 1,449 GitHub stars · LeRobot Discord (channel mobile-so100-arm); 158 GitHub forks |
| Kits | Full kits from Seeed Studio and others (e.g. WowRobo) |
Licenses
| Design files | Apache-2.0 (repo-wide LICENSE.txt; STLs and URDF in the same repo) source ↗ |
|---|---|
| Code | Apache-2.0 source ↗ |
| Documentation | Apache-2.0 (repo-wide; no separate docs license) source ↗ |
Builder notes
Practical points from the project's issue tracker, forum and docs, each linked to its source.
- The EU 12V battery in the parts list originally had different terminals and dimensions than the US one and didn't fit the printed mount. A separate EU battery mount STL was added. source ↗
- The EU parts list still links a 3A 12V-to-5V converter where a 5A part is intended (issue open). source ↗
- A 2026 proposal, closed without merging, argued that even a nominal 5V 5A converter may not give a Raspberry Pi 5 its full power budget unless the supply and cable signal 5A capability over USB-C. source ↗
- The base servos are the same STS3215 used in the arm. The pricier listing only adds a Feetech controller board that LeKiwi doesn't use. source ↗
- One builder's arm jittered at rest on the mobile base, and halving the P gain on the first motor (32 to 16) calmed it. source ↗
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