Open source Mini humanoids & bipeds
Zeroth-01 Bot (K-Scale)
An ultra-low-cost, hackable 3D-printed mini humanoid from the K-Scale Labs community: 16 Feetech bus servos, about US$347 in electronics, with end-to-end sim-to-real RL.
- Type
- Mini humanoid
- DoF
- 16
- Servos
- Feetech STS3250 × 16
- Controller
- Milk-V Duo S
- BOM cost
- ≈ US$347 (electronics)
- Status
- K-Scale closed in Nov 2025; project open-sourced
- Open hardware and open code
- Full bill of materials with supplier links
- Direct links to the original CAD, code and papers
01 — Project details
Overview, BOM and resources
Overview
Zeroth-01 (formerly MicroStompy) is the K-Scale Labs community’s entry-level humanoid — “BOM starts at $350”. Printed parts plus 16 bus servos, with a camera, microphone and round display for vision and voice.
K-Scale Labs ceased operations in November 2025 and open-sourced all K-Bot and Zeroth Bot hardware and software (hardware CERN-OHL-S-2.0, software MIT). The old docs site is offline; GitHub is now the source of truth.
Key specifications
| Servos | 16 × Feetech STS3250 50 kg bus servos (STS3215 is too slow, no longer recommended) |
|---|---|
| Controller | Milk-V Duo S + Waveshare bus-servo adapter |
| Sensors | Adafruit 9-DoF IMU, Milk-V camera, microphone, 3 W speaker, RP2040 round LCD |
| Software | kos-zbot (robot OS), ksim-gym-zbot (RL training) |
Bill of materials
Electronics total ≈ US$347 (servos at historical price; current price varies by seller). Fasteners and prints are unpriced in the official BOM.
| Part | Model / spec | Qty | Unit | Subtotal | Supplier |
|---|---|---|---|---|---|
| Electronics | |||||
| STS3250 50KG Serial Bus Servo | 16 | $13.89 | $222.24 | aliexpress.us ↗ | |
| Milk-V | 1 | $10.00 | $10.00 | milkv.io ↗ | |
| Waveshare Bus Servo Adapter | 1 | $7.00 | $7.00 | waveshare.com ↗ | |
| RP2040 MCU Board | 1 | $16.00 | $16.00 | waveshare.com ↗ | |
| 9-DOF IMU | 1 | $29.95 | $29.95 | adafruit.com ↗ | |
| Milk-V CAM-GC2083 | 1 | $4.00 | $4.00 | arace.tech ↗ | |
| RC Lipos | 1 | $33.00 | $33.00 | amazon.com ↗ | |
| 12V to 5V, 3 amp capacity (may need connectors) | 1 | $3.00 | $3.00 | digikey.com ↗ | |
| Electret Microphone | 1 | $6.00 | $6.00 | amazon.com ↗ | |
| 3 Watt Speaker | 1 | $8.00 | $8.00 | amazon.com ↗ | |
| LM386 Mono Audio Amplifier | 1 | $8.00 | $8.00 | amazon.com ↗ | |
| Total | $347.19 | ||||
Optional items, tools and reference items (not counted)
| Part | Model / spec | Qty | Unit | Subtotal | Supplier |
|---|---|---|---|---|---|
| Fasteners | |||||
| Button Head Cap Screw | M3 x 10 mm | 14 | |||
| Button Head Cap Screw | M3 x 4.5 mm | 129 | |||
| Button Head Cap Screw | M2 x 5 mm | 80 | |||
| Socket Head Cap Screw | M2 x 5 mm | 12 | |||
| Heat-Set Insert | M3 | 13 | |||
| Heat-Set Insert | M2 | 14 | |||
| M3x12 screw + nut | M3 x 12 | 4 | |||
| Structural | |||||
| 3D-printed parts (see STL pack) | see print pack | ||||
| Total | $347.19 | ||||
3D printing & fabrication
- Official settings (Bambu): 0.16 mm layers, 5 walls, tree supports; filament is not specified — PLA or PETG both work.
- The official print pack has 22 STLs and a Bambu .3mf plate (hands, elbows, shoulders, head, neck, torso, hips, knees, ankles, feet).
CAD, code & papers
Get the large files — CAD, STL, STEP and code — straight from the original project:
- GitHub zeroth-bot ↗github.com
- Releases (URDF, CAD) ↗github.com
- Docs source (incl. STL) ↗github.com
- Custom PCBs ↗github.com
- Robot software kos-zbot ↗github.com
- RL training ksim-gym-zbot ↗github.com
- CAD (Onshape) ↗cad.onshape.com
License
The zeroth-bot repository currently carries only an MIT license (the README says MIT too). K-Scale’s November 2025 shutdown announcement says hardware is released under CERN-OHL-S-2.0 and software under MIT, but no CERN-OHL-S file has been added to the repository yet — follow the repository files and keep attribution.
Image credits
- Image 1: Zeroth Robotics / K-Scale Labs · repo MIT — source ↗
- Image 2: Zeroth Robotics / K-Scale Labs · repo MIT — source ↗
- Image 3: Zeroth Robotics / K-Scale Labs · repo MIT — source ↗
- Image 4: Zeroth Robotics / K-Scale Labs · repo MIT — source ↗
- Image 5: Zeroth Robotics / K-Scale Labs · repo MIT — source ↗
- Image 6: Zeroth Robotics / K-Scale Labs · repo MIT — source ↗
Source: Images and data: Zeroth Robotics / K-Scale Labs community (GitHub zeroth-robotics, kscalelabs). Repository code MIT; on shutting down K-Scale announced the hardware under CERN-OHL-S-2.0. This site is not affiliated with the original project.
Show original text (中文)
项目概况
Zeroth-01（原名 MicroStompy）是 K-Scale Labs 社区做的入门级人形机器人，官方口号是“BOM 起步价 350 美元”。全身打印件加 16 个总线舵机，配摄像头、麦克风和圆形屏幕，可以跑视觉和语音。
K-Scale Labs 已于 2025 年 11 月停止运营，并宣布把 K-Bot 和 Zeroth Bot 的软硬件全部开源（硬件 CERN-OHL-S-2.0，软件 MIT）。原文档站已下线，资料以 GitHub 仓库为准。
关键参数
| 舵机 | 16 × Feetech STS3250 50 kg 总线舵机（STS3215 速度不够，不再推荐） |
|---|---|
| 主控 | Milk-V Duo S + Waveshare 总线舵机转接板 |
| 传感器 | Adafruit 9 轴 IMU、Milk-V 摄像头、麦克风、3 W 喇叭、RP2040 圆形屏 |
| 软件 | kos-zbot（机器人系统）、ksim-gym-zbot（强化学习） |
物料清单 BOM
电子件合计约 USD 347（舵机按历史价，现价随卖家浮动）；紧固件和打印件官方没有标价。
| 零件 | 型号 / 规格 | 数量 | 单价 | 小计 | 购买链接 |
|---|---|---|---|---|---|
| Electronics | |||||
| STS3250 50KG Serial Bus Servo | 16 | $13.89 | $222.24 | aliexpress.us ↗ | |
| Milk-V | 1 | $10.00 | $10.00 | milkv.io ↗ | |
| Waveshare Bus Servo Adapter | 1 | $7.00 | $7.00 | waveshare.com ↗ | |
| RP2040 MCU Board | 1 | $16.00 | $16.00 | waveshare.com ↗ | |
| 9-DOF IMU | 1 | $29.95 | $29.95 | adafruit.com ↗ | |
| Milk-V CAM-GC2083 | 1 | $4.00 | $4.00 | arace.tech ↗ | |
| RC Lipos | 1 | $33.00 | $33.00 | amazon.com ↗ | |
| 12V to 5V, 3 amp capacity (may need connectors) | 1 | $3.00 | $3.00 | digikey.com ↗ | |
| Electret Microphone | 1 | $6.00 | $6.00 | amazon.com ↗ | |
| 3 Watt Speaker | 1 | $8.00 | $8.00 | amazon.com ↗ | |
| LM386 Mono Audio Amplifier | 1 | $8.00 | $8.00 | amazon.com ↗ | |
| 合计 | $347.19 | ||||
可选件、工具与参考条目（不计入合计）
| 零件 | 型号 / 规格 | 数量 | 单价 | 小计 | 购买链接 |
|---|---|---|---|---|---|
| Fasteners | |||||
| Button Head Cap Screw | M3 x 10 mm | 14 | |||
| Button Head Cap Screw | M3 x 4.5 mm | 129 | |||
| Button Head Cap Screw | M2 x 5 mm | 80 | |||
| Socket Head Cap Screw | M2 x 5 mm | 12 | |||
| Heat-Set Insert | M3 | 13 | |||
| Heat-Set Insert | M2 | 14 | |||
| M3x12 screw + nut | M3 x 12 | 4 | |||
| Structural | |||||
| 3D 打印件（见 STL 包） | 见 02_3D打印材料 | ||||
| 合计 | $347.19 | ||||
3D 打印与制造
- 官方参数（Bambu）：层高 0.16 mm、5 圈墙、树状支撑；耗材官方未指定，PLA / PETG 均可。
- 官方打印包含 22 个 STL 和一份 Bambu 打印板 .3mf（手、肘、肩、头、颈、躯干、髋、膝、踝、脚）。
图纸、程序与论文
大文件（CAD、STL、STEP、代码仓库）请直接从原项目获取：
- GitHub zeroth-bot ↗github.com
- 发布页（URDF、CAD） ↗github.com
- 文档源文件（含 STL） ↗github.com
- 定制电路板 ↗github.com
- 机器人系统 kos-zbot ↗github.com
- 强化学习 ksim-gym-zbot ↗github.com
- CAD（Onshape） ↗cad.onshape.com
开源协议
zeroth-bot 仓库目前只有 MIT 许可（README 同样写 MIT）。K-Scale 2025-11 关停声明说硬件按 CERN-OHL-S-2.0、软件按 MIT 开源，但仓库里还没有 CERN-OHL-S 硬件许可文件；使用前以仓库文件为准并保留署名。
图片来源与授权
- 图 1：Zeroth Robotics / K-Scale Labs · 仓库 MIT — 来源 ↗
- 图 2：Zeroth Robotics / K-Scale Labs · 仓库 MIT — 来源 ↗
- 图 3：Zeroth Robotics / K-Scale Labs · 仓库 MIT — 来源 ↗
- 图 4：Zeroth Robotics / K-Scale Labs · 仓库 MIT — 来源 ↗
- 图 5：Zeroth Robotics / K-Scale Labs · 仓库 MIT — 来源 ↗
- 图 6：Zeroth Robotics / K-Scale Labs · 仓库 MIT — 来源 ↗
Get the parts
Where to get the parts
Every line in the BOM links to the supplier the original team used. Need help sourcing parts or 3D-printing the structure? Tell us which robot you are building.
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