Koch v1.1 Teleop Arm

Koch v1.1 is a low-cost, open-source 6-DOF 3D-printed robot arm pair engineered for imitation-learning research. A lightweight leader arm acts as the human interface; a stronger follower arm replicates the motion in the real world. Both limbs are printed from PLA/PLA+ on a consumer FDM printer, snap together without special tooling, and are driven by Dynamixel XL-series servos (XL430 for high-torque joints, XL330 for the wrist). A single Waveshare USB-C servo bus board streams commands from any laptop or SBC, so the whole rig can be built and controlled for ≈ $600 in parts. The project ships with out of the box with HuggingFace’s LeRobot framework: record kinesthetic demonstrations, store them in a public dataset, and train vision-based policies with a few CLI commands. Because trajectories are saved in the standard LeRobot format, they can be shared on the HuggingFace Hub and re-used by the community—turning every build into a potential data contribution. Creator Jess Moss publishes the CAD, BOM, and firmware under the permissive MIT license, encouraging remixing and redistribution. The design is intentionally modular: joints are identical mirrored segments, servo horns are printable, and the gripper can be swapped for a low-cost vacuum cup or a custom end-effector. If you want an entry point into real-world imitation learning that you can build in a weekend and expand indefinitely, Koch v1.1 is it.

Printing

Koch v1.1 is a teleoperation pair: you print BOTH a leader arm (the lightweight handheld controller) and a follower arm (the stronger arm that mirrors your motion). All parts below are print-one-each — there are no duplicates, mirrors, or alternates in this set. PLA/PLA+ on a consumer FDM printer; ~297 cm³ total filament.

Follower arm — print one each (7):

• Follower_Base
• Follower_Shoulder_Rotation
• Follower_Shoulder_To_Elbow
• Follower_Elbow_To_Wrist
• Follower_Elbow_To_Wrist_Extension
• Follower_Gripper_Static_Part
• Follower_Gripper_Moving_Part

Leader arm — print one each (7):

• Leader_Base
• Leader_Platform
• Leader_Shoulder_To_Elbow
• Leader_Elbow_To_Wrist
• Leader_Elbow_To_Wrist_Extension
• Leader_Gripper_Handle
• Leader_Gripper_Trigger

Servo frame adapter (1): fpx330.stl is the Robotis FPX330-S101 servo frame part used in the chain — print one.

Servos (not printed): Follower uses 2× Dynamixel XL430-W250-T (base/shoulder) + 4× XL330-M288-T (elbow/wrist/gripper); Leader uses 6× XL330-M077-T. Driven by a single Waveshare serial bus servo board.

Optional extras (not included here): The upstream repo also has two decorative branding plates (HuggingFace_Block, LeRobot_Block) that are purely cosmetic and not part of the functional arm — left out intentionally. Add them only if you want the branded base plate.