Robots & Kits

SO-101 arm

A desktop 5+1 DOF arm, the successor to SO-100, with parts from about USD 110. Open hardware with a published bill of materials — the most literal use of 'open source' at this price point: you can source the parts and change the structure yourself, and its limits are stated just as plainly.

Blueprints

Blueprints · B

A USD 110 arm: why SO-101 is the one to build first

At the low end this is the most literal use of "open source": you can buy the parts, change the structure and replace …

SO-101 arm · Feetech STS series servos · LeRobot · 2026-09-28

Software

Software · A

LeRobot: turning "collect data, then make it move" into scripts

Apache 2.0, Python, and currently the shortest path from nothing to a moving robot on the hobbyist side. The barrier i…

LeRobot · SO-101 arm · LeRobot Humanoid · 2026-09-28

Hardware

Hardware · B

A 20 kg-cm servo: measured under what conditions?

Servos often account for more than half the bill of materials of a desktop robot, and their headline number is the lea…

Feetech STS series servos · SO-101 arm · 2026-09-28

Claim Check

Claim Check · B

"Open source" — which layer is actually open?

The most common phrase on a spec sheet, and in DIY circles it is read as "I can repair it, modify it and replicate it"…

Unitree G1 · SO-101 arm · LeRobot Humanoid · Dynamixel and the ROBOTIS ecosystem · 2026-09-28

Claim Check · B

More degrees of freedom is better — the most popular claim, and the easiest to falsify

Degrees of freedom is the easiest number to compare on a spec sheet and the easiest to charge more for. It is also the…

Unitree G1 · SO-101 arm · LeRobot Humanoid · 2026-09-28