Leader/follower arm · 2025
Koch v1.1
A pair of arms: one leader you physically move by hand, one follower that mirrors it. Dynamixel XL430 servos give the leader real torque feedback, so teleoperation feels like the real thing instead of a mouse.
$400
Alexander Koch
6 (5 + gripper) DOF
Open source
Why it matters
Best teleoperation quality per dollar. The leader arm's torque feedback is what makes demonstration data good enough to train on.
Where it falls short
Two arms means double the BOM, double the calibration. Plastic-gear XL430s limit payload.
Read this if you plan to copy itThe parts below are the same classes of component at this platform scale — they are not the exact vendor parts. Use them to understand the architecture and to price a home-built equivalent.
What it is made of
| Subsystem | Comparable part | Price | Primary spec |
|---|---|---|---|
| Actuators | Dynamixel XL430-W250-T | $50 | 1.5 N·m @ 12 V |
| Structure | PA-CF printed structural parts | $40 | ~70 – 100 MPa (depends on print) |
| Power | Pololu D24V50F5 buck regulator | $20 | 6 – 38 V |
Software you would touch
LeRobot · Dynamixel SDK · Python