Alexander Koch (original); v1.1 by Jess Moss (open source) Koch v1.1 Low-Cost Robot Arm (1)

~$477 DIY parts (pair)BOM totals: ~$199 for the leader arm and ~$278 for the follower (US), mostly Dynamixel servos. PartaBot sells kits.

AvailablePython from a laptopDynamixel servosLeRobotLeader–follower teleop

Possibly ≤ 1 weekShipping: Parts in days; assembly required. Parts are available from Robotis US and Amazon; assembled kits are sold by PartaBot (US).

Remote control: USB to a laptop; LeRobot's Python tools handle calibration, teleop, recording and policy rollout.

Koch v1.1 GitHub ↗Original low_cost_robot ↗

Overview

Alexander Koch's March 2024 low-cost arm was the first hardware LeRobot supported; v1.1 (July 2024) cleaned up the CAD, removed soldering and added a leader-arm platform. Dynamixel servos make it smoother but pricier than the SO-100/101, which has largely replaced it as the community default.

Specifications

Category	Robot arms · Desktop & hobby arms
Released	2024
Availability	Available
Programmability	Open source (hardware + software)
Best for	Ages 14+ (estimated)
Vision sensors	No vision sensors
Actuators	Smart servos (Dynamixel, Feetech…)
Audio	No audio
Compute type	Laptop / PC as the brain
Remote control	Python from a laptop
DOF	6 (5 joints + gripper)
Reach	Not published
Payload	Not published
Repeatability	Not published
Weight	Not published
Controller	None on the arm; serial servo driver board to a host PC over USB
Sensors	Servo position feedback (Robotis Dynamixel XL430 / XL330)
SDK	Hugging Face `lerobot` (Python); original repo includes Python scripts