Open source Mini humanoids & bipeds
ToddlerBot 2.0
A 0.56 m open-source humanoid from Stanford with 30 active DoF, almost entirely 3D-printed and driven by Dynamixel servos — built for ML data collection and loco-manipulation research.
- Type
- Mini humanoid
- DoF
- 30
- Height
- 0.56 m
- Weight
- 3.4 kg
- BOM cost
- ≈ US$5,727.94 (2XC)
- Structure
- PLA-CF + PLA
- 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
ToddlerBot was developed at Stanford by Haochen Shi, C. Karen Liu, Shuran Song and colleagues as a low-cost, easy-to-repair ML platform — a broken part can be reprinted the same day.
Version 2.0 (August 2025) comes in a default 2XC build and a stronger 2XM build. The team publishes an assembly manual, PCB files, RL training and diffusion-policy code.
Key specifications
| Actuators | ROBOTIS Dynamixel: 2XC430, 2XL430, XC330, XC430, XM430 (2XM adds XM430-W350) |
|---|---|
| DoF layout | 7 per arm, 6 per leg, 2 waist, 2 neck |
| Computer | NVIDIA Jetson Orin NX 16GB (Orin Nano works on a budget) |
| Sensors | 2 × fisheye USB cameras, BNO085 IMU, speaker |
| Cost | 2XC $5,727.94; 2XM $7,293.56 (tools excluded) |
Bill of materials
Total US$5,727.94 (default 2XC, tools excluded); the 2XM build is about US$7,293.56. Pre-assembled kit, optional gripper, tools and extras are listed below and not counted.
| Part | Model / spec | Qty | Unit | Subtotal | Supplier |
|---|---|---|---|---|---|
| Essentials | |||||
| DYNAMIXEL 2XC430-W250-T | DYNAMIXEL 2XC430-W250-T - ROBOTIS | 2 | $298.89 | $597.78 | robotis.us ↗ |
| DYNAMIXEL 2XL430-W250-T | DYNAMIXEL 2XL430-W250-T - ROBOTIS | 6 | $149.39 | $896.34 | robotis.us ↗ |
| DYNAMIXEL XC330-T288-T | DYNAMIXEL XC330-T288-T - ROBOTIS | 6 | $103.39 | $620.34 | robotis.us ↗ |
| DYNAMIXEL XC430-T240BB-T | DYNAMIXEL XC430-T240BB-T - ROBOTIS | 4 | $137.89 | $551.56 | robotis.us ↗ |
| DYNAMIXEL XM430-W210-T | DYNAMIXEL XM430-W210-T - ROBOTIS | 4 | $310.39 | $1,241.56 | robotis.us ↗ |
| DYNAMIXEL XM430-W350-T | DYNAMIXEL XM430-W350-T - ROBOTIS | 0 | $310.39 | $0.00 | robotis.us ↗ |
| DYNAMIXEL HN11-I101 Set | HN11-I101 Set - ROBOTIS | 10 | $8.05 | $80.50 | robotis.us ↗ |
| DYNAMIXEL HN12-I101 Set | HN12-I101 Set - ROBOTIS | 4 | $20.47 | $81.88 | robotis.us ↗ |
| Jetson Orin NX 16G | NVIDIA® Jetson Orin™ NX 16GB AI Device - reComputer J4012 | 1 | $955.00 | $955.00 | seeedstudio.com ↗ |
| M.2 CB375NF Wifi Card | Amazon.com: AW-CB375NF Wireless NIC, 2.4G/5GHz Dual-Band WiFi 5 Supports BLE, NGFF (M.2 … | 1 | $18.36 | $18.36 | amazon.com ↗ |
| WiFi Antenna | Amazon.com: WiFi 6E Antenna IPX MHF4 Tri-Band 6GHz 5GHz 2.4GHz Internal Laptop Wi-Fi Ant… | 1 | $9.49 | $9.49 | amazon.com ↗ |
| FIsheye Camera | Amazon.com: Arducam 1080P Low Light WDR Ultra Wide Angle USB Camera Module for Computer,… | 2 | $49.99 | $99.98 | amazon.com ↗ |
| Phone Speaker | 1 | $5.99 | $5.99 | amazon.com ↗ | |
| Speaker Driver | Amazon.com: HiLetgo 3pcs M38 Wireless Bluetooth MP3 Audio Receiver Board BLT 4.2 mp3 Los… | 1 | $7.99 | $7.99 | amazon.com ↗ |
| BNO085 IMU | Adafruit 9-DOF Orientation IMU Fusion Breakout - BNO085 (BNO080) [STEMMA QT / Qwiic] : I… | 1 | $24.95 | $24.95 | adafruit.com ↗ |
| M2*6 Pre-coated Screws | 200 | $0.01 | $1.80 | e.tb.cn ↗ | |
| M2 Screw Kit | Amazon.com: Kadrick 304 Stainless Steel Screws,660 Pcs M2 Screw Assortment,Button Head S… | 2 | $8.99 | $17.98 | amazon.com ↗ |
| M2.5 Screw Kit | 705 Pieces M2.5 Screws Nuts Washers Set Black, Sutemribor M2.5 x 4/6/8/10/12/16/20mm But… | 1 | $9.99 | $9.99 | amazon.com ↗ |
| M3 Flat Head Screw Kit | 565 Pieces M3 Screws Nuts Washers Set Black, Sutemribor M3 x 5/6/8/10/12/16/20mm Counter… | 1 | $9.99 | $9.99 | amazon.com ↗ |
| M3*8 Set Screw | 50 Pcs M3x8mm Metric 304 Stainless Steel Hex Socket Set Flat Point Grub Screws Silver To… | 1 | $6.99 | $6.99 | amazon.com ↗ |
| M3*10 Set Screw | 50 Pcs M3x10mm Metric 304 Stainless Steel Hex Socket Set Flat Point Grub Screws Silver T… | 1 | $6.99 | $6.99 | amazon.com ↗ |
| M4 Screw Kit | iexcell 675 Pcs M4 x 6/8/10/12/16/20/25/30/35/40 Alloy Steel 10.9 Grade Hex Socket Butto… | 1 | $22.38 | $22.38 | amazon.com ↗ |
| M4 Long Screw Kit | iexcell 50 Pcs M4 x 40/45/50/55/60mm Thread Pitch 0.7 mm Stainless Steel 304 Hex Socket … | 1 | $9.58 | $9.58 | amazon.com ↗ |
| M3 and M4 Lock Nuts Kit | 182 Pieces 304 Stainless Steel Lock Nuts | 1 | $7.98 | $7.98 | amazon.com ↗ |
| Vibra-TITE 213 Threadlocker | Amazon.com: Vibra-TITE 213 VC-3 Threadmate Threadlocker, -65 to 165 Degree F, 5mL Tube, … | 1 | $6.55 | $6.55 | amazon.com ↗ |
| Bearing 683 10pcs | uxcell 683-2RS Deep Groove Ball Bearing 3x7x3mm Double Sealed ABEC-3 Bearings 10-Pack: A… | 1 | $11.96 | $11.96 | amazon.com ↗ |
| Bearing 684 10pcs | 684ZZ Bearing 4X9X4 mm ABEC-5 (10 PCS) Miniature 684Z Ball Bearings 684 ZZ 618/4ZZ Hobby… | 2 | $7.99 | $15.98 | amazon.com ↗ |
| Bearing AXK0414 | 1Pcs Plane Thrust Needle Roller Bearing AXK0414 0515 0619 0821 1024 1226 1528 1730 2035 … | 30 | $1.48 | $44.40 | aliexpress.us ↗ |
| Bushing 3*5*5 10pcs | uxcell Sleeve Bearings 3mm Bore x 5mm OD x 5mm Length Plain Bearings Wrapped Oilless Bus… | 1 | $5.99 | $5.99 | amazon.com ↗ |
| 5mm Rubber Tape | 1 | $16.99 | $16.99 | amazon.com ↗ | |
| Step Down Power Converter 12V 4.5A | Pololu - 12V, 4.5A Step-Down Voltage Regulator D36V50F12 | 2 | $34.95 | $69.90 | pololu.com ↗ |
| USB to Mirco USB Cable 0.5 Feet | 1 | $5.98 | $5.98 | amazon.com ↗ | |
| USB to Mirco USB Cable 1.5 Feet | 1 | $8.99 | $8.99 | amazon.com ↗ | |
| USB Hub Port Splitter | 1 | $6.98 | $6.98 | amazon.com ↗ | |
| Jumper Wire | 1 | $6.98 | $6.98 | amazon.com ↗ | |
| JST EH Cable | 10 | $0.38 | $3.82 | digikey.com ↗ | |
| JST EH Housing | 25 | $0.05 | $1.17 | digikey.com ↗ | |
| 5 Pairs of XT30 Male and Female Plugs | 1 | $9.99 | $9.99 | amazon.com ↗ | |
| XT30 to XT60 Male Female 4 pcs | 1 | $8.99 | $8.99 | amazon.com ↗ | |
| Barrel Jack Connector | 1 | $9.49 | $9.49 | amazon.com ↗ | |
| Rocker Switch 5 pcs | 1 | $5.99 | $5.99 | amazon.com ↗ | |
| 2000 mAh Lipo Battery | 1 | $49.99 | $49.99 | ||
| Lipo Battery Voltage Tester | 1 | $12.95 | $12.95 | amazon.com ↗ | |
| Lipo Battery Balance Charger | 1 | $31.99 | $31.99 | ||
| 14 AWG Power Extension Cable | 1 | $17.49 | $17.49 | amazon.com ↗ | |
| PLA-CF 1KG | 2 | $34.99 | $69.98 | us.store.bambulab.com ↗ | |
| PLA 1KG | 1 | $19.99 | $19.99 | us.store.bambulab.com ↗ | |
| Total | $5,727.94 | ||||
Optional items, tools and reference items (not counted)
| Part | Model / spec | Qty | Unit | Subtotal | Supplier |
|---|---|---|---|---|---|
| Essentials | |||||
| ToddlerBot 2.0 Fully Assembled | 1 | $4,299.00 | $4,299.00 | shop.wowrobo.com ↗ | |
| DYNAMIXEL XC330-T288-T | DYNAMIXEL XC330-T288-T - ROBOTIS | 2 | $103.39 | $206.78 | robotis.us ↗ |
| Tools | |||||
| Bambu Lab X1-Carbon Combo 3D Printer | 1 | $1,449.00 | $1,449.00 | ||
| Bambu Smooth PEI Plate | 1 | $37.99 | $37.99 | us.store.bambulab.com ↗ | |
| Liquid Glue for Build Plate | 1 | $16.99 | $16.99 | us.store.bambulab.com ↗ | |
| Anti-vibration Foot | 1 | $10.99 | $10.99 | ||
| 30V 10A Power Supply | 1 | $119.99 | $119.99 | amazon.com ↗ | |
| Banana Plug Cables | 1 | $9.99 | $9.99 | amazon.com ↗ | |
| Screwdriver Kit | 1 | $64.99 | $64.99 | amazon.com ↗ | |
| Precision Screwdriver Kit | 1 | $29.99 | $29.99 | amazon.com ↗ | |
| Allen Key Set | 1 | $6.95 | $6.95 | amazon.com ↗ | |
| Pliers | 1 | $32.35 | $32.35 | amazon.com ↗ | |
| Caliper Digital | 1 | $29.98 | $29.98 | amazon.com ↗ | |
| Double Sided Tape | 1 | $9.99 | $9.99 | amazon.com ↗ | |
| Automatic Wire Stripper | 1 | $9.99 | $9.99 | amazon.com ↗ | |
| Soldering Tweezer | 1 | $5.99 | $5.99 | amazon.com ↗ | |
| Soldering Brass | 1 | $11.97 | $11.97 | amazon.com ↗ | |
| Soldering Station | 1 | $69.99 | $69.99 | amazon.com ↗ | |
| Black Silicone Repair Mat | 1 | $8.53 | $8.53 | amazon.com ↗ | |
| Heat Shrink Tube | 1 | $6.99 | $6.99 | amazon.com ↗ | |
| Heat Shrink Butt Connectors 100 pcs | 1 | $9.49 | $9.49 | amazon.com ↗ | |
| Helping Hands Soldering | 1 | $23.99 | $23.99 | amazon.com ↗ | |
| 60/40 Tin Lead Solder Wire | 1 | $9.99 | $9.99 | amazon.com ↗ | |
| Additional Features | |||||
| 20 Set 4040 Connector | 1 | $24.99 | $24.99 | amazon.com ↗ | |
| 4040 Aluminum Extrusion 500mm | 1 | $55.99 | $55.99 | amazon.com ↗ | |
| M5 T-Nuts Screws Kit 200pcs | 1 | $13.99 | $13.99 | amazon.com ↗ | |
| 2020 Aluminum Extrusion 100mm | 1 | $18.99 | $18.99 | amazon.com ↗ | |
| DYNAMIXEL 2XL430-W250-T | 6 | $129.90 | $779.40 | robotis.us ↗ | |
| DYNAMIXEL XC430-T240BB-T | 2 | $119.99 | $239.98 | robotis.us ↗ | |
| Dynamixel U2D2 USB Comm Module | 1 | $32.10 | $32.10 | robotis.us ↗ | |
| Dynamixel U2D2 Power Hub Board Set | 1 | $19.00 | $19.00 | robotis.us ↗ | |
| Breadboard Kit | 1 | $6.99 | $6.99 | amazon.com ↗ | |
| LilyGo T-Display S3 | 1 | $27.50 | $27.50 | amazon.com ↗ | |
| Round Force Sensitive Resistor (FSR) | 2 | $4.46 | $8.92 | adafruit.com ↗ | |
| Resistor Kit | 1 | $9.99 | $9.99 | amazon.com ↗ | |
| E stop Switch | 1 | $6.99 | $6.99 | amazon.com ↗ | |
| Rog Ally X | 1 | $900.00 | $900.00 | bestbuy.com ↗ | |
| 21700 Cell | 6 | $8.49 | $50.94 | ||
| 21700 Battery Holder | 1 | $12.99 | $12.99 | amazon.com ↗ | |
| JST XH balancing plug | 1 | $16.99 | $16.99 | amazon.com ↗ | |
| Portable Bench Clamp | 1 | $26.98 | $26.98 | amazon.com ↗ | |
| Total | $5,727.94 | ||||
3D printing & fabrication
- Materials: 2 kg Bambu PLA-CF (carbon-fibre PLA) + 1 kg PLA Basic.
- The team prints on a Bambu X1-Carbon, about 10 hours per plate; orientation and settings matter for strength.
- Official plates (19 each for 2XC / 2XM) are on MakerWorld (sign-in required); parts can also be exported from Onshape.
Official MakerWorld plate list (19 each for 2XC / 2XM, 38 in total)
The print files themselves need a MakerWorld sign-in: 2XC ↗ · 2XM ↗ · Download the plate list (.csv)
| Build | # | Plate | Filament | Hours | Settings |
|---|---|---|---|---|---|
| 2XC | 1 | Arm | PLA-CF 94 g / 31.75 m | 4.14 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 2 | Arm2 | PLA-CF 94 g / 31.75 m | 4.14 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 3 | Leg_L | PLA-CF 120 g / 40.77 m | 4.72 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 4 | Leg_R | PLA-CF 120 g / 40.83 m | 4.72 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 5 | Torso | PLA-CF 312 g / 106.17 m | 9.95 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 6 | Safety Stand | PLA 60 g / 18.85 m | 1.55 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 7 | SysID | PLA 211 g / 66.46 m | 5.52 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 8 | Calibratior1 | PLA 298 g / 98.33 m | 8.36 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 9 | Teleop | PLA 353 g / 116.37 m | 6.86 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 10 | Torso+Head+Neck parts | PLA-CF 61 g / 20.48 m | 3.09 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 11 | Head cover | PLA-CF 70 g / 23.77 m | 3.94 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 12 | Calibrator2 | PLA 165 g / 54.39 m | 4.38 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 13 | Waist | PLA-CF 86 g / 28.98 m | 3.8 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 14 | Gripper | PLA-CF 197 g / 66.91 m | 8.88 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 15 | Foot without Rubber | PLA-CF 34 g / 11.37 m | 1.13 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 16 | Palm with TPU | TPU 62 g / 20.68 m | 5.07 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 17 | Foot with Rubber | PLA-CF 27 g / 8.92 m | 0.96 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 18 | Palm with Rubber | PLA-CF 42 g / 14.09 m | 1.39 | 0.2mm layer, 6 walls, 25% infill |
| 2XC | 19 | PLA 3 g / 0.77 m；PLA-CF 28 g / 9.27 m | 1.01 | 0.2mm layer, 6 walls, 25% infill | |
| 2XM | 1 | Arm | PLA-CF 94 g / 31.75 m | 4.14 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 2 | Arm2 | PLA-CF 94 g / 31.75 m | 4.14 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 3 | Leg_L | PLA-CF 136 g / 46.12 m | 5.33 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 4 | Leg_R | PLA-CF 136 g / 46.14 m | 5.34 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 5 | Torso | PLA-CF 275 g / 93.39 m | 8.37 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 6 | Safety Stand | PLA 60 g / 18.84 m | 1.56 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 7 | SysID | PLA 212 g / 66.46 m | 5.53 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 8 | Calibratior1 | PLA 299 g / 98.33 m | 8.36 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 9 | Teleop | PLA 345 g / 113.58 m | 6.34 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 10 | Torso+Head+Neck parts | PLA-CF 58 g / 19.63 m | 2.93 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 11 | Head cover | PLA-CF 70 g / 23.66 m | 3.91 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 12 | Calibrator2 | PLA 165 g / 54.39 m | 4.38 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 13 | Waist | PLA-CF 81 g / 27.52 m | 3.54 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 14 | Gripper | PLA-CF 188 g / 63.88 m | 8.33 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 15 | Foot without Rubber | PLA-CF 34 g / 11.37 m | 1.16 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 16 | Palm with TPU | TPU 61 g / 20.17 m | 4.88 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 17 | Foot with Rubber | PLA-CF 27 g / 8.92 m | 0.97 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 18 | Palm with Rubber | PLA-CF 40 g / 13.39 m | 1.24 | 0.2mm layer, 6 walls, 25% infill |
| 2XM | 19 | Front cover | PLA 3 g / 0.80 m；PLA-CF 28 g / 9.27 m | 1.02 | 0.2mm layer, 6 walls, 25% infill |
CAD, code & papers
Get the large files — CAD, STL, STEP and code — straight from the original project:
- Project page ↗toddlerbot.github.io
- Documentation ↗hshi74.github.io
- GitHub ↗github.com
- CAD (Onshape) ↗cad.onshape.com
- 3D print files 2XC (MakerWorld) ↗makerworld.com
- 3D print files 2XM (MakerWorld) ↗makerworld.com
- Paper arXiv:2502.00893 ↗arxiv.org
- Demo video ↗youtu.be
License
Code and docs MIT; mechanical design (Onshape, STL) CC BY-NC-SA 4.0.
Image credits
- Image 1: Haochen Shi et al., ToddlerBot authors (Stanford TML) · design CC BY-NC-SA 4.0 — source ↗
- Image 2: Haochen Shi et al., ToddlerBot authors (Stanford TML) · CC BY-NC-SA — source ↗
- Image 3: Haochen Shi et al., ToddlerBot authors (Stanford TML) · CC BY-NC-SA — source ↗
- Image 4: Haochen Shi et al., ToddlerBot authors (Stanford TML) · design CC BY-NC-SA 4.0 — source ↗
- Image 5: Haochen Shi et al., ToddlerBot authors (Stanford TML) · design CC BY-NC-SA 4.0 — source ↗
- Image 6: Haochen Shi et al., ToddlerBot authors (Stanford TML) · design CC BY-NC-SA 4.0 — source ↗
Source: Images and data: Stanford ToddlerBot project (website, docs, GitHub and arXiv:2502.00893). Code and docs MIT; mechanical design CC BY-NC-SA 4.0. This site is not affiliated with the original project.
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.
02 — Related robots
