2,642 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 little star of the *Galactic Starcruiser* walkabout experience and several Disney+ trailers). Designed by **Antoine Pirrone (apirrone)**, Open Duck Mini scales that silhouette down to about **35 cm tall** and lets you build one for a few hundred dollars in parts. ## What it is A walking, head-tilting, antenna-twitching little biped with serious character. Under the cute exterior it's a legitimate RL-trained biped: - Legs trained in Isaac Gym, sim-to-real transferred to physical hardware - Standing-up-from-fall policy with demonstrated perturbation robustness - Sim2Sim pipeline through Mujoco for validation before hardware deployment - Head + antennas add expressiveness on top of the locomotion stack ## Hardware - **Servos**: Dynamixel XC330-M288-T across all joints (upgraded from XL330 for torque headroom on landing impacts) - **IMU**: BNO055 9-axis for base orientation estimate - **Compute**: an onboard board (RPi-class or similar SBC) running the learned policy - **Battery**: small LiPo in the cage, hot-swappable ## What you can do with it - **Run the pretrained walking policy** straight from the repo — step the robot around, send it forward/turn commands over the orobot cloud surface. - **Collect your own episodes** — use the remote surface here as the operator input for demos. - **Research biped RL** — swap in your own PPO / SAC training runs; the Mujoco and Isaac scenes are all published. - **Character animation** — antenna and head servos give it genuine personality for demos, events, or as a companion prop. ## Printed parts (canonical set shipped with this program) - `head`, `body_part` — shell and torso - `hip_left_roll_to_pitch`, `hip_right_roll_to_pitch` — hip assemblies - `renfort_leg` — leg reinforcement - `axis_to_axis`, `block_to_axis` — joint linkages - `foot` — contact surface - `cage_top`, `cage_bottom`, `cage_back` — internal electronics cage - `antenna`, `antenna_tip` — head antennas The full repo includes ~130 STLs covering wiring routing, battery variants, and community mods (see Jaime's v2 mods and Justin's "Park Head" variant in the upstream `print/mods/` tree). ## Attribution & license - Designer: **Antoine Pirrone** (apirrone) - Upstream: https://github.com/apirrone/Open_Duck_Mini - License: **Apache 2.0** - Related: Duck community mods + variants under `print/mods/` in the upstream repo ## Links - Upstream: https://github.com/apirrone/Open_Duck_Mini - Training code: https://github.com/apirrone/Open_Duck_Mini_Runtime - BDX inspiration: Disney's Galactic Starcruiser droid --- ## Install Notes The orobot `start` action runs the MuJoCo **simulation training script** (`v2_rl_walk_mujoco.py`), not the physical robot deployment. The actual walking firmware for the physical duck lives in a separate repository: [apirrone/Open_Duck_Mini_Runtime](https://github.com/apirrone/Open_Duck_Mini_Runtime). To run on hardware, clone the Runtime repo separately, deploy to a Raspberry Pi Zero 2W, and update the `start` action in this Program's editor to point at the Runtime's main script.
Category: Humanoids
| Part | Qty | Unit Price | Total | Notes | |------|-----|------------|-------|-------| | 18650 cell | 2 | €1.75 | €3.50 | | | 18650 cell holder | 1 | €4.99 | €4.99 | | | 2S BMS | 1 | €8.40 | €8.40 | | | 5V regulator | 1 | €24.78 | €24.78 | | | IMU | 1 | €48.30 | €48.30 | Expensive — consider cheaper alternative | | Raspberry Pi Zero 2W | 1 | €26.08 | €26.08 | Onboard compute | | Micro USB cable | 2 | €9.99 | €19.98 | | | XC-330-M288-T servo | 10 | €110.40 | €1,104.00 | Legs — upgraded from XL-330 for power | | XL-330-M288-T servo | 3 | €45.76 | €137.28 | | | U2D2 (Dynamixel USB adapter) | 1 | €56.16 | €56.16 | Can substitute cheaper alternative | | U2D2 power hub | 1 | €23.34 | €23.34 | | | M3 heat-set inserts | 1 pack | €5.99 | €5.99 | | | Force resistive sensors | 2 packs | €9.20 | €18.40 | 4 total needed (2 per foot) | | 90° micro USB adapter | 1 | €7.69 | €7.69 | | | Small power switch | 1 | €7.49 | €7.49 | 1 needed from pack | | USB-C charger | 1 | €9.99 | €9.99 | 1 needed from pack | | 9g servo | 1 pack | €9.99 | €9.99 | 2 needed; pack of 3 | | PLA filament | — | — | — | Standard PLA for structural parts | | TPU filament | — | — | — | Flexible material for feet | | **Total** | | | **~€1,516** | |