






ToddlerBot
About this program
ToddlerBot is a low-cost, open-source humanoid robot platform designed for scalable policy learning and research in robotics and AI. Standing approximately 50cm tall and weighing around 2.5kg, it features 23 Dynamixel servo motors (XC330 or XM430 series), a Jetson Orin NX compute module, custom TTL power PCB, stereo depth camera, and 6-axis IMU. The codebase covers low-level control, reinforcement learning training with MuJoCo/MJX, diffusion policy training, and real-world deployment. Two variants are available: toddlerbot_2xc (budget-friendly, XC330 motors) and toddlerbot_2xm (stronger, XM430 motors). Supported capabilities include bipedal walking, whole-body locomotion over obstacles, keyframe animation playback, VR teleoperation, and loco-manipulation.
Attribution
Author: Haochen Shi, Weizhuo Wang, Shuran Song, C. Karen Liu (Stanford) License: Code: MIT · Hardware design (STL/CAD): CC BY-NC-SA 4.0 Source: https://github.com/hshi74/toddlerbot Papers: ToddlerBot (2025) · Locomotion Beyond Feet (2026) CAD: Onshape · MakerWorld
Printing
⚠️ This Print All set is incomplete and not yet build-ready. ToddlerBot is a 23-DOF humanoid that needs roughly 50 printed structural parts, but this list currently holds only 12 — and those 12 are _visual meshes auto-imported from the robot’s URDF/simulation description, not the official print files. The set is also left/right asymmetric (e.g. left_ankle_pitch, left_elbow_roll, left_gripper, left_shoulder_pitch are present with no right-side counterparts), so it cannot build a complete robot as-is.
Where the real print files live: the ToddlerBot authors distribute the printable parts as a ready-to-slice 3MF release on MakerWorld (makerworld.com/en/models/1733983) and as editable CAD on Onshape — both linked in the Attribution section above. The upstream GitHub repo (hshi74/toddlerbot) contains only MuJoCo _visual/_collision simulation meshes organized by servo/config variant (toddlerbot_2xc, toddlerbot_2xm, gripper/palm options), not a clean printable STL set, so a faithful set can’t simply be pulled from git.
To build one: download the MakerWorld 3MF release for your chosen variant — toddlerbot_2xc (budget XC330 motors) or toddlerbot_2xm (stronger XM430 motors) — and print on a BambuLab-class printer using the included orientations/profiles (part strength depends on correct orientation). Most limb/link parts come in mirrored left/right pairs.
The 12 meshes here are kept as a structural reference/preview only. (Catalog note: this is a known gap — the importer pulled sim meshes instead of the MakerWorld print set; see the related platform issue about importer mesh filtering.)
🖨 Print Files (12)
torso_visual.stl
pelvis_link_visual.stl
left_hip_pitch_link_visual.stl
left_knee_link_visual.stl
left_ankle_pitch_link_visual.stl
right_hip_pitch_link_visual.stl
Required Hardware
| Item | Qty | Notes |
|---|---|---|
| Dynamixel XC330-M288-T (or XM430-W350-T) | 23 | Main servo actuators; XC330 for budget, XM430 for performance |
| Jetson Orin NX 8GB (or 16GB) | 1 | Main compute module |
| Custom TTL Power PCB v8 | 1 | PCB files in repo docs/_static |
| 4S 2200mAh LiPo Battery | 1 | 14.8V nominal |
| U2D2 USB-to-TTL adapter | 1 | For Dynamixel communication |
| OAK-D Lite Stereo Camera | 1 | Depth + stereo vision |
| 6-axis IMU (e.g., Bosch BNO085) | 1 | Attitude estimation |
| M2 / M3 / M4 screws & heat-set inserts | ~200+ | Various lengths; see assembly manual |
| 3D-printed structural parts | ~50 | PLA-CF recommended; plates on MakerWorld |
| Voltage tester display | 1 | Battery monitoring |
| E-Stop button | 1 | Safety cutoff for motors |
| Bambu X1C or compatible 3D printer | 1 | Recommended for tolerances |
| Electric screwdriver | 1 | Needed for M2/M3/M4 assembly |
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