Open-source robot arms
Robot arms you can build, from low-cost arms driven by serial bus servos to stepper-driven desktop arms, plus bimanual arm workcells.
The atlas lists 18 open-source robot arms. 9 publish a URDF or MJCF model for simulation. 9 publish a build cost; the US-dollar figures run from $122 for SO-101 (follower arm only) to $20k for ALOHA (tutorial BOM total; additional power and cable items listed separately). 15 carry a hardware license that permits commercial use, and 3 are licensed for non-commercial use only. The most-starred source repository here is SO-101's, with 7.6k GitHub stars.
Compare the robot arms
Sorted by reproducibility score. A cost is the figure the source publishes, in its own currency, with its basis and what it covers.
| Robot | Cost | DoF | Hardware license | Sim model | Score |
|---|---|---|---|---|---|
| Koch v1.1ManipulatorDormant | $477source total, leader and follower arms | 6 | Apache-2.0Commercial use OK | none published | 89 |
| OpenArmManipulator | not published | 8 | CERN-OHL-S-2.0Commercial use OK | URDF | 89 |
| Seeed reBot-DevArmManipulator | not published | 7 | CERN-OHL-W-2.0Commercial use OK | none published | 83 |
| SO-101Manipulator | $122source total, follower arm only | 6 | Apache-2.0Commercial use OK | URDF | 83 |
| SO-ARM100 / SO-ARM101 (Standard Open Arm)ManipulatorDeprecated | $123source total, follower arm only | 6 | Apache-2.0Commercial use OK | URDF | 83 |
| SmallRobotArm (Skyentific)ManipulatorDormant | not published | 6 | GPL-3.0Commercial use OK | none published | 80 |
| ThorManipulator | €350source total, hardware components, excluding the 3D printer | 6 | CC-BY-SA-4.0Commercial use OK | URDF | 80 |
| Seeed reCamera GimbalPan-tilt gimbal | not published | 2 | Apache-2.0Commercial use OK | none published | 75 |
| PAROL6 Desktop Robot ArmManipulator | €2.4kvendor kit, PAROL6 kit, all parts except 3D printed parts and power supply | 6 | GPL-3.0Commercial use OK | URDF | 73 |
| PingTi ArmManipulator | $261source total, single PingTi arm: 2 STS3250, 6 STS3215, Feetech USB board, clamps, Dupont wire; excludes power supply and printed parts | 6 | Apache-2.0Commercial use OK | URDF | 73 |
| BCN3D MoveoManipulatorDormant | not published | 6 | MITCommercial use OK | none published | 65 |
| ROBOTIS OpenManipulator-XManipulator | $1.6kvendor kit, RM-X52-TNM kit (5 XM430-W350-T, frames, cables, tools); excludes SMPS, U2D2/OpenCR, base plate | 5 | CC-BY-4.0Commercial use OK | URDF | 65 |
| ALOHABimanualDormant | $20ksource total, tutorial BOM total; additional power and cable items listed separately | 14 | MITCommercial use OK | none published | 63 |
| Pedro 2.0Manipulator | not published | 4 | Apache-2.0Commercial use OK | none published | 63 |
| AR4 (Annin Robotics)Manipulator | not published | 6 | Annin Robotics Open Source Non-Commercial License 1.1Non-commercial | URDF | 60 |
| Moss v1 Robot ArmsManipulatorDeprecated | $288source total, two-arm leader and follower set, README US prices, excludes printing | 6 | Apache-2.0Commercial use OK | none published | 57 |
| ArduinobotManipulator | not published | 4 | CC-BY-NC-4.0Non-commercial | URDF | 20 |
| MOTUSManipulatorDormant | not published | 6 | CC-BY-NC-SA-4.0Non-commercial | none published | 13 |
Robot arms in 3D
Renders come from each project's own source files; a card says so when there is no model yet.
Side-by-side comparisons
Cost, DoF, actuators, simulation models, license and every score criterion, with the robots drawn to scale. Pick your own with the Compare button on each card.
Parts these robot arms use
From the robots' bills of materials: how many of the robots above list each part.