PingTi Arm is an open-source, human-scale robotic arm built for affordability and compatibility with the SO-ARM100 ecosystem. Its name comes from the Chinese "平替" (píng tì), meaning "affordable substitute" — the arm delivers human arm proportions at a fraction of typical robot arm costs. Designed to be fully compatible with Hugging Face's LeRobot framework, PingTi Arm supports teleoperation, imitation learning data collection, and policy deployment out of the box via the pingti_lerobot_bridge SDK. **Key specs:** - **Reach:** 600mm arm span (excluding end effector) - **Payload:** Up to 500g at full extension - **Joints:** 6 DOF: base yaw, dual-motor shoulder pitch, elbow pitch, wrist pitch, wrist roll + gripper - **Servos:** STS3215 Feetech serial bus smart servos (same family as SO-ARM100) - **Build cost:** ~$261 single arm | ~$390 leader-follower pair - **SO-100 upgrade path:** If you already own an SO-100 arm (12V, 30kg.cm variant), you only need 2 additional servos + a USB drive board (~$157) to assemble PingTi - **Simulation:** Full URDF and collision meshes included for MuJoCo/Isaac Sim **Why human-scale?** Most low-cost robot arms (SO-100, Koch v1) are tabletop-scale. PingTi Arm's 600mm span covers real desktop-manipulation tasks — grasping objects at the edge of a table, pouring, stacking — that shorter arms can't reach without repositioning. **LeRobot integration:** Connect PingTi Arm as a follower in a leader-follower teleoperation setup using SO-100 as leader. Record demonstrations, train ACT or Diffusion Policy, and deploy. The pingti_lerobot_bridge repo provides all the calibration and control scripts. Hardware and software licensed under Apache 2.0. Original design by nomorewzx — https://github.com/nomorewzx/PingTi-Arm
Category: Arm Robots
| Qty | Part | Notes | |-----|------|-------| | 1 | **Human arm scale**: 600mm arm span (excluding the end effector). | - | | 1 | **Reasonable payload**: Supports up to 500g at maximum arm span. | - | | 1 | **Support setting up Leader-Follower arms** you can setup a pair of Leader-Follower arm using PingTi Arm as follower arm and SO-100 as leader arm | - | | 1 | - A single PingTi arm costs ~ USD 261, | - | | 1 | - A Lead-Follower setup costs ~ USD 390. | - | | 1 | - If you already own an SO-100 follower arm (12V, 30kg.cm servos), you only need 2 additional servos and a USB drive board (~$157) to assemble the PingTi arm. | - | | 1 | [3D Printing](./docs/3d_print.md) | - | | 1 | I strongly recommend you to start with [SO-100](https://github.com/TheRobotStudio/SO-ARM100) and come to PingTi Arm if you are interested in: | - | | 1 | As stated before, if you assemble SO-100 with the `12V 30KG.cm` servos, you only need buy 2 more servos and 1 more USB control board to onboard PingTi arm. There is no waste of money | - | | 1 | Avoid sudden movement and stop with heavy payload (e.g. 500g) | - | | 1 | [SO-100](https://github.com/TheRobotStudio/SO-ARM100) | - |