Auto-assembled, not yet reviewed

PingTi Arm

Human-scale low-cost arm based on SO-100, LeRobot-compatible.

Reproducibility73/100Partial source coverage, unverifiedCADBOMWIREFWBUILDLICREPHow it is computed
PingTi Arm open-source 6-DoF robot arm, 3D render from PingTi_Arm_v3.urdf
main assembly 3D · PingTi_Arm_v3.urdf

About PingTi Arm

PingTi Arm is an open-source robotic arm built on the SO-100 design, with a 600 mm human-scale span and up to 500 g payload at full extension. It uses two STS3250 and six STS3215 serial-bus servos, works with LeRobot through the pingti_lerobot_bridge SDK, and supports a leader and follower setup with PingTi as the follower and an SO-100 as the leader. The BOM follows the upstream English table and adds the 12V 5A power supply listed in the Chinese table; it mixes USD and CNY prices, so no single USD total is given.

Licenses

Hardware
Apache-2.0
Software
Apache-2.0
Docs
Not published

Degrees of freedom

6 DoF arm 5gripper 1

Breakdown source

Serial armsource

How to build PingTi Arm

5 steps

Steps marked Motari summary condense the linked source; follow the source for exact instructions. Upstream step marks a step taken from the linked guide.

  1. Print the structural parts

    Print the link and gripper STLs from /stl_3d_printing; increase infill density for heavier payloads.

    Motari summarygithub.com/nomorewzx/PingTi-Arm/blob/main/docs/Assembe_tutor...

  2. Source the servos

    Acquire two STS3250 and six STS3215 servos per the BOM; reuse an existing SO-100 follower if you have one.

    Motari summarygithub.com/nomorewzx/PingTi-Arm/blob/main/docs/Assembe_tutor...

  3. Connect and configure the servos

    Connect a 12V power supply and the servos to the Feetech USB drive board as shown in the assembly tutorial, then set servo IDs 1 to 8 one servo at a time with LeRobot. The two STS3250 servos get IDs 2 and 3. Do this before assembling the links.

    Upstream stepgithub.com/nomorewzx/PingTi-Arm/blob/9108729b79bc3509642386b...

  4. Assemble the links

    Follow docs/Assembe_tutorial.md to bolt the printed links to the servo horns from the base up.

    Upstream stepgithub.com/nomorewzx/PingTi-Arm/blob/9108729b79bc3509642386b...

  5. Run LeRobot

    Use the pingti_lerobot_bridge SDK for teleoperation and data collection, pairing with an SO-100 leader.

    Upstream stepgithub.com/nomorewzx/PingTi-Arm/blob/9108729b79bc3509642386b...
Print time20 h
Assembly timenot published

Wiring, power and firmware are safety-relevant and shown for reference only. Check them against the source before building.

PingTi Arm bill of materials

6 rows

Cost to build

$261.09USDsource total
  • single PingTi arm: 2 STS3250, 6 STS3215, Feetech USB board, clamps, Dupont wire; excludes power supply and printed parts$261.09source total

In the source currency, as read on 2026-09-30. Not converted, and not checked against current vendor prices: none of these is a Motari-verified checkout total.

PingTi Arm parts, as the source lists them (read 2026-06-07). Prices are the source's, not checked against vendors.

PingTi Arm bill of materials
PartQtySpecSourceConfidence
STS3250 Servo12V, 50 kg.cm servos; both sit in the dual-servo shoulder joint (IDs 2 and 3)
2Feetech STS3250, 360-degree metal serial servo
Alibaba$73.89 eachnomorewzx/PingTi-Arm docs/BOM_List.md line 11
high
STS3215 Servo (12V, 30 kg.cm)12V serial-bus servos from the source BOM
6Feetech STS3215, 12V, 30 kg.cm
Alibaba$13.89 eachnomorewzx/PingTi-Arm docs/BOM_List.md line 12
high
Motor Control BoardFeetech USB bus servo board
1Feetech USB drive board
Alibaba$7.05nomorewzx/PingTi-Arm docs/BOM_List.md line 13
high
Table Clamp 2pcs6-inch table clamp pair
12-piece clamp set
Amazon$9.00nomorewzx/PingTi-Arm docs/BOM_List.md line 14
high
Dupont WireBreadboard jumper wire set
1assorted Dupont jumper wires
Amazon$6.98nomorewzx/PingTi-Arm docs/BOM_List.md line 15
high
Power Supply (12V5A)12V5A supply listed in the Chinese PingTi BOM
112V, 5A DC supply
Tmall / Taobao¥35.00nomorewzx/PingTi-Arm docs/BOM_List_CN.md line 11
high

Rows from the source's own parts list 23

docs/BOM_List_CN.md@9108729markdown

Source rowQtyPrice and vendorLine
STS3250 Servo (12V, 50kg.cm)
2
淘宝链接item.taobao.com464.00
L8
STS3215 Servo (12V, 30kg.cm)
6
淘宝链接item.taobao.com115.00
L9
总线舵机驱动板
1
淘宝链接item.taobao.com45.00
L10
电源 (12V5A)
1
淘宝链接detail.tmall.com35.00
L11
桌面夹(2支)
1
淘宝链接detail.tmall.com19.50
L12
杜邦线 Dupont Wire
1
淘宝链接detail.tmall.com2.35
L13
STS3215 Servo (7.4V, 19kg.cm)
6
淘宝链接item.taobao.com99.00
L20
舵机总线控制板
1
淘宝链接item.taobao.com24.00
L21

4 more rows in docs/BOM_List_CN.md

docs/BOM_List.md@9108729markdown

Source rowQtyPrice and vendorLine
STS3250 Servo
2
Alibabaalibaba.com$73.89
L11
STS3215 Servo (12V,30 kg.cm)
6
Alibabaalibaba.com$13.89
L12
Motor Control Board
1
AmazonAlibaba$7.05
L13
Table Clamp 2pcs
1
Amazonamazon.com$9.00
L14
Dupont Wire
1
Amazonamazon.com$6.98
L15
STS3215 Servo (7.V, 20kg.cm)
6
Alibabaalibaba.com$14
L30
Motor Control Board
1
Amazonamazon.com$11
L31
USB-C Cable 2 pcs
1
Amazonamazon.com$7
L32

3 more rows in docs/BOM_List.md

PingTi Arm source files

8 files

Files stay in the upstream repository under their own licenses; these links open them there. The 3D model on this page is Motari's conversion of the file named under Simulation.

PingTi Arm in simulation

Robot description files a simulator or CAD tool can load, linked at the commit they were found.

The 3D specimen on this page is converted from Simulation/PingTi_Arm_v3/urdf/PingTi_Arm_v3.urdf at 9108729.

Builds of PingTi Arm

0 reviewed

No reviewed builds of PingTi Arm yet.

A build log records the evidence (photos, a video, your repository), what the build cost, how long it took and what you changed. Each one is checked by Motari (until a maintainer claims this page) before it shows here, and reviewed builds count toward the reproducibility score.

Sources and provenance

Sources

Last push to nomorewzx/PingTi-Arm: 2025-12-08 (checked 2026-10-01)

Related links

How this page was made

Assembled from public sources on 2026-06-04, not yet reviewed by the maintainer. Each figure links to where it is stated; a value the sources do not state reads "not published". Last source review: 2026-06-07 nomorewzx/PingTi-Arm BOM_List.md.

Original files stay intact and separately licensed; Motari adds only the summary on this page. Maintainer? Request a correction or removal.

Badge for the README

Maintain PingTi Arm? Show its reproducibility score in the project's README. The badge links back to this page and updates with the score.

Badge: reproducibility 73/100

Markdown
[![Motari reproducibility score for PingTi Arm](https://motari.io/api/v1/badge/pingti-arm)](https://motari.io/r/pingti-arm)
HTML
<a href="https://motari.io/r/pingti-arm"><img src="https://motari.io/api/v1/badge/pingti-arm" alt="Motari reproducibility score for PingTi Arm" height="20"></a>

Not fully met yet: cad / mesh present (partial), wiring diagram (partial). The score is read from the project's own sources, so publishing what is missing is what raises it. A score of 90 or more needs a reviewed build. How the score is computed