Koch v1.1
Low-cost open-source arm with five joints plus a gripper, built from ROBOTIS Dynamixel XL430 and XL330 servos. Koch v1.1 is Jess Moss's revision of Alexander Koch's original design to make assembly easier. LeRobot supports it natively as a leader/follower pair.
open hardware · Apache-2.0 (Koch v1.1 repo); MIT (original low_cost_robot repo)LeRobot native since 0.3.2verified 2026-10-24aka Koch arm, Koch v1.1, low_cost_robot, Low-Cost Robot Arm, koch_follower, koch_leader
Policies on Koch v1.1 7 with evidence · 1 unknown
| Policy | State | Tier | Verified | Detail |
|---|---|---|---|---|
| ACT Imitation | works | T1 · upstream documented | 2026-10-24 1d ago | |
| Diffusion Policy Imitation | partial | T3 · community reported | 2026-10-24 1d ago | Training evidenced by public checkpoint(s); on-robot inference not documented by a primary source. |
| OpenVLA VLA | partial | T3 · community reported | 2026-10-24 1d ago | Training evidenced by public checkpoint(s); on-robot inference not documented by a primary source. |
| π0-FAST VLA | partial | T3 · community reported | 2026-10-24 1d ago | Training evidenced by public checkpoint(s); on-robot inference not documented by a primary source. |
| π0 VLA | partial | T3 · community reported | 2026-10-24 1d ago | Training evidenced by public checkpoint(s); on-robot inference not documented by a primary source. |
| π0.5 VLA | partial | T3 · community reported | 2026-10-24 1d ago | Training evidenced by public checkpoint(s); on-robot inference not documented by a primary source. |
| SmolVLA VLA | partial | T3 · community reported | 2026-10-24 1d ago | Training evidenced by public checkpoint(s); on-robot inference not documented by a primary source. |
No verified evidence, but both are available in LeRobot (ecosystem context): EO-1, Evo-1, Fast-WAM, GR00T N1.7, HIL-SERL, LingBot-VA, MolmoAct2, Multitask DiT, TD-MPC, VLA-JEPA, VQ-BeT, WALL-OSS, X-VLA.
Not yet verified: OpenVLA-OFT. Have evidence?
Specifications
- Degrees of freedom
- 5 (Six motors per follower: shoulder_pan, shoulder_lift, elbow_flex, wrist_flex, wrist_roll + gripper.)src
- Arms
- 1
- Actuators
- Follower: 2x Dynamixel XL430-W250 (shoulder) + 4x XL330-M288. Leader (v1.1 BOM): 6x Dynamixel XL330-M077-T.src
- Price (USD)
- $278–$477 (Self-sourced parts cost from the Koch v1.1 README (US links): follower arm $278, leader arm $199, so $477 for the pair. Excludes 3D printing.)src
- BOM / build
- github.com/jess-moss/koch-v1-1
- Homepage
- github.com/jess-moss/koch-v1-1
- Supported sensors
- RGB, single camera, RGB, two cameras (wrist + overview), RGB, three or more cameras, Intel RealSense depth
- Teleoperation
- Koch leader arm (koch_leader)
LeRobot's Koch docs link to the v1.1 repo (jess-moss/koch-v1-1) for sourcing and assembly. Before the v0.3 hardware API redesign, main also had a koch_bimanual type. Bimanual Koch is not registered in v0.6.1.
Framework support
Sources
- T1 · upstream documentedofficial-docssource 2026-08-03verified 2026-10-24 (1d ago)lerobot 0.6.1
LeRobot README lists Koch among natively supported hardware.
“SO100, LeKiwi, Koch, HopeJR, OMX, EarthRover, Reachy2, Gamepads, Keyboards, Phones, OpenARM, Unitree G1, reBot B601.”
https://github.com/huggingface/lerobot/blob/v0.6.1/README.md - T1 · upstream documentedofficial-docssource 2026-08-03verified 2026-10-24 (1d ago)lerobot 0.6.1
LeRobot Koch v1.1 guide; points to the jess-moss/koch-v1-1 README for sourcing.
“Follow the sourcing and assembling instructions provided in this [README](https://github.com/jess-moss/koch-v1-1).”
https://github.com/huggingface/lerobot/blob/v0.6.1/docs/source/koch.mdx - T1 · upstream documentedsource-codesource 2026-08-03verified 2026-10-24 (1d ago)lerobot 0.6.1
Registers the koch_follower robot type.
“@RobotConfig.register_subclass("koch_follower")”
https://github.com/huggingface/lerobot/blob/v0.6.1/src/lerobot/robots/koch_follower/config_koch_follower.py - T1 · upstream documentedsource-codesource 2026-08-03verified 2026-10-24 (1d ago)lerobot 0.6.1
Follower motor map: xl430-w250 for shoulder pan/lift, xl330-m288 for the rest including gripper.
“"shoulder_lift": Motor(2, "xl430-w250", norm_mode_body), "elbow_flex": Motor(3, "xl330-m288", norm_mode_body),”
https://github.com/huggingface/lerobot/blob/v0.6.1/src/lerobot/robots/koch_follower/koch_follower.py - T1 · upstream documentedsource-codesource 2025-08-01verified 2026-10-24 (1d ago)lerobot 0.3.2
koch_follower already registered at v0.3.2 (first tagged release).
“@RobotConfig.register_subclass("koch_follower")”
https://github.com/huggingface/lerobot/blob/v0.3.2/src/lerobot/robots/koch_follower/config_koch_follower.py - T1 · upstream documentedvendor-docsverified 2026-10-24 (1d ago)
Koch v1.1 BOM: leader total $199 (6x XL330-M077-T), follower total $278.
“| Total | | $278 |”
https://github.com/jess-moss/koch-v1-1/blob/1a553e1fa7d5404b51bbd83b99b0f7eba54888e0/README.md - T1 · upstream documentedvendor-docsverified 2026-10-24 (1d ago)
Original design uses XL430 for the first two joints and XL330 elsewhere.
“This robot arm uses Dynamixel XL430 and Dynamixel XL330 servo motors. The XL430 motors are almost twice as strong and are used for the first two joints.”
https://github.com/AlexanderKoch-Koch/low_cost_robot/blob/0602b0c1e6a67d8f6ab96f81d1378639018d98af/README.md