Open Duck Mini
✓ Links verified Aug 31, 2026
Sign up to InstallAbout this program
3,406 stars on GitHub.
Open Duck Mini — Bipedal BDX Droid Replica
Source: https://github.com/apirrone/Open_Duck_Mini
A miniature bipedal character robot inspired by Disney's BDX droid — the small two-legged star of the Galactic Starcruiser walkabout experience. Standing roughly 42 cm tall with its legs extended, Open Duck Mini v2 recreates the droid's expressive, duck-like gait in a fully open-source design that targets a complete bill of materials under $400.
The mechanical design is authored in Onshape and simulated in MuJoCo, with locomotion trained end-to-end through reinforcement learning. The project has put heavy work into sim-to-real transfer, publishing trained ONNX walking policies that run on the robot itself. The onboard runtime executes those policies on a Raspberry Pi Zero 2 W, and the training stack is moving to MuJoCo Playground alongside a reference-motion generator for imitation learning.
Planned "expression" features — LED eyes, a camera, a speaker and a microphone — extend the base walker into a fuller character robot and can be added after the build. The project is documented as it evolves (print guide, assembly guide, and a community Tnkr build guide), backed by an active Discord community, and sponsored by Hugging Face and Pollen Robotics.
🖨 Print Files (33)
head.stl
body_part.stl
foot.stl
cage_top.stl
cage_bottom.stl
cage_back.stl
antenna.stl
antenna_tip.stl
hip_left_roll_to_pitch.stl
hip_right_roll_to_pitch.stl
renfort_leg.stl
axis_to_axis.stl
Required Hardware
| Item | Qty | Unit Cost (USD) | Total (USD) | Notes |
|---|---|---|---|---|
| Feetech STS3215 serial bus servo (7.4V, 19.5 kg·cm) | 14 | $23 | $318 | Leg & neck joints — Amazon 6-pack ×2 + Amazon 2-pack — ~$14/ea if sourced via AliExpress/Alibaba |
| 9 g micro servo (SG90 / FS90) | 2 | $4 | $8 | Antennae / accessory motion — Amazon search |
| Waveshare bus-servo adapter board | 1 | $12 | $12 | Half-duplex serial bus driver for STS3215 — Amazon |
| Raspberry Pi Zero 2 W | 1 | $18 | $18 | Compute — PiShop.us ($17.25, in stock) — Amazon only stocks $80+ kits |
| MicroSD card 32 GB (U3, High Endurance) | 1 | $23 | $23 | Boot — SanDisk High Endurance 32GB |
| BNO055 IMU module (I²C) | 1 | $16 | $16 | Body orientation — Amazon (GY-BNO055) — cheaper clones on AliExpress |
| Molicel INR18650-P30B 3000 mAh cell | 2 | $7 | $14 | High-discharge for servo bus — nkon.nl (frequently out of stock — any high-drain 18650 pair works) |
| 2S 18650 battery holder (with leads) | 1 | $6 | $6 | Amazon |
| 2S Li-ion BMS (6A balance) | 1 | $10 | $10 | Cell protection — Amazon |
| 5V UBEC regulator (8A) | 1 | $19 | $19 | 5V rail for Pi — Amazon (FEICHAO UBEC) / Amazon search |
| Latching power switch (illuminated) | 1 | $5 | $5 | Amazon search |
| USB-C 2-cell Li-ion charger module (TP4056-class for 2S) | 1 | $11 | $11 | Battery charging — Amazon |
| 2.1 mm DC barrel jack (panel-mount) | 2 | $2 | $4 | Amazon 6-pack |
| XT30 connector pairs | 4 | $1 | $4 | Servo-bus power — Amazon 20-pair pack |
| SS-10 microswitch (foot contact) | 4 | $1 | $4 | Ground-contact detection — Amazon search |
| 608ZZ ball bearing (8×22×7) | 3 | $2 | $6 | Hip pivot — Amazon 10-pack $5 |
| M3 heat-set threaded inserts (100-pack) | 1 | $7 | $7 | Amazon search |
| Spiral cable sheath / split-loom (3 m, 6 mm) | 1 | $10 | $10 | Wire management — Amazon search |
Explore similar robots












B