Auto-assembled, not yet reviewed

openDog V3

James Bruton's third-gen brushless quadruped with cycloidal drives and ODrive control.

Dormant. No upstream changes for two years or more. It may still build, but parts, firmware and docs may have drifted.

Last push to XRobots/openDogV3: 2023-03-19 (GitHub, checked 2026-10-01).

Repository activity

Reproducibility68/100Partial source coverage, unverifiedCADBOMWIREFWBUILDLICREPHow it is computed
openDog V3 open-source 12-DoF robot dog, 3D render from openDog V3.zip
main assembly 3D · openDog V3.zip

About openDog V3

openDog V3 is the third generation of James Bruton's open-source quadruped. Each of the 12 joints uses a brushless motor with a 3D-printed cycloidal drive, driven by ODrive controllers with AS5047P absolute encoders. The repo ships a zipped main STEP assembly, additional component CAD, Arduino control code and a BOM.ods spreadsheet listing motors, belts, carbon-fiber tube, electronics, batteries, bearings, fasteners, nylon washers and spacers with quantities and example suppliers. The 3D view is the main CAD assembly from CAD/openDog V3.zip.

Licenses

Hardware
MIT
Software
MIT
Docs
Not published

Degrees of freedom

12 DoF legs 12

Breakdown source

Quadrupedsource

How to build openDog V3

5 steps

Steps marked Motari summary condense the linked source; follow the source for exact instructions.

  1. Print the cycloidal drives and frame

    Print all parts in PLA from the STEP CAD. Larger parts: around 15% infill, 3 perimeters, 0.3 mm layers. Smaller parts such as the cycloidal drive internals: 4 perimeters and up to 30 to 40% infill.

    Motari summarygithub.com/XRobots/openDogV3

  2. Build the cycloidal actuators

    Assemble each of the 12 cycloidal drives around a 9225 90 KV brushless motor using the BOM bearings, steel pins, washers and spacers, and fit one AS5047P encoder per motor. The knees are driven by HTD 5M belts.

    Motari summarygithub.com/XRobots/openDogV3

  3. Wire the ODrives

    In the ODrive tool, configure the AS5047 encoders for absolute position mode and run the offset calibration per the ODrive documentation. The ODriveInit.ino routine then sets the current limit and closed loop control.

    Motari summarygithub.com/XRobots/openDogV3

  4. Cast the feet

    Use the provided foot mould CAD and 25A Shore platinum-cure silicone over carbon-fibre tubes.

    Motari summarygithub.com/XRobots/openDogV3

  5. Flash, calibrate, and walk

    Upload openDogV3.ino with kinematics, calibrate joint zeros, then run the IK and gait modes from the remote.

    Motari summarygithub.com/XRobots/openDogV3
Print timenot published
Assembly timenot published

Wiring, power and firmware are safety-relevant and shown for reference only. Check them against the source before building.

openDog V3 bill of materials

10 rows

Cost to build

The sources do not publish a cost total. The rows below are what they list, without a sum.

openDog V3 parts, as the source lists them. Prices are the source's, not checked against vendors.

openDog V3 bill of materials
PartQtySpecSourceConfidence
9225 90 KV brushless motorsGeneral Parts / Motor row
12Turnigy Multistar 9225 90 KV or EaglePower 8308 stator / 9225 can 90 KV motors
example suppliers from the project's BOMprice not listedBOM.ods in XRobots/openDogV3 at commit 537aa0d
high
HTD 5M 630 mm knee drive beltsGeneral Parts / Belts row
4HTD 5M pitch, 630 mm length timing belts for knee drives
example suppliers from the project's BOMprice not listedBOM.ods in XRobots/openDogV3 at commit 537aa0d
high
28 mm OD carbon fiber tubeGeneral Parts / Carbon Fiber tube row
428 mm outer diameter, at least 1 mm wall; four 1 m lengths cut to CAD dimensions
example suppliers from the project's BOMprice not listedBOM.ods in XRobots/openDogV3 at commit 537aa0d
high
ODrive 3.6 BLDC motor driversElectronics row
6ODrive 3.6 dual-axis BLDC motor drivers; source note says 2 per axis
ODrive Robotics / supplier from the project's BOMprice not listedBOM.ods in XRobots/openDogV3 at commit 537aa0d
high
AMS AS5047P motor encodersElectronics row
12AS5047P absolute magnetic motor encoders, one per axis
Digi-Key / supplier from the project's BOMprice not listedBOM.ods in XRobots/openDogV3 at commit 537aa0d
high
Dog and remote microcontrollersElectronics rows
2Teensy 4.1 for the robot and Teensy LC for the remote
example suppliers from the project's BOMprice not listedBOM.ods in XRobots/openDogV3 at commit 537aa0d
high
Dog and remote electronics setElectronics rows
15V regulator, MPU6050 IMU, NRF24L01 radios, D-range connectors, switches, volt meters, LCD, encoder cable, joysticks, toggles and momentary switches
example suppliers from the project's BOMprice not listedBOM.ods in XRobots/openDogV3 at commit 537aa0d
high
Main and electronics batteriesBatteries rows
26S high-drain LiPo main battery and 2S small electronics battery
example suppliers from the project's BOMprice not listedBOM.ods in XRobots/openDogV3 at commit 537aa0d
high
Cycloidal drive bearing setBearings rows
1384 internal 12x4x4 mm bearings, 36 cam/cap 32x20x7 mm bearings, 24 top/bottom 85x65x10 mm bearings, plus thin-wall, knee, and knee-idler bearings
example suppliers from the project's BOMprice not listedBOM.ods in XRobots/openDogV3 at commit 537aa0d
high
Cycloidal drive pin and fastener setSteel bar, Nuts & Bolts, Nylon rows
14 mm steel bar pins; M4/M3 motor, cam, output, case, axis, and leg fasteners; nylon washers and 4 mm ID spacers
example suppliers from the project's BOMprice not listedBOM.ods in XRobots/openDogV3 at commit 537aa0d
high

Rows from the source's own parts list 9

BOM.ods@537aa0dods

Source rowQtyPrice and vendorLine
BOM.ods scope and columns
raw.githubusercontent.comno price listed
L1
9225 90 KV brushless motors
12
aliexpress.comno price listed
L1
HTD 5M 630 mm knee drive belts
4
beltingonline.comno price listed
L1
28 mm OD carbon fiber tube
4
ebay.co.ukno price listed
L1
ODrive and encoder electronics
6 ODrive, 12 encoders, 1 Teensy 4.1, 1 Teensy LC
odriverobotics.comdigikey.co.ukno price listed
L1
Dog and remote electronics set
assorted electronics quantities listed in ODS
source-listed example suppliersno price listed
L1
Main and electronics batteries
1 main battery, 1 electronics battery
hobbyking.comno price listed
L1
Cycloidal drive bearing set
384 + 36 + 24 + 8 + 8 + 16 bearing quantities
AliExpress / Simply Bearings example suppliersno price listed
L1

1 more rows in BOM.ods

openDog V3 source files

9 files

Files stay in the upstream repository under their own licenses; these links open them there. The 3D model on this page is Motari's conversion of the file named under Simulation.

openDog V3 in simulation

Robot description files a simulator or CAD tool can load, linked at the commit they were found.

No URDF, MJCF, SDF, USD or Onshape model has been found in the sources.

The 3D specimen on this page is converted from CAD/openDog V3.zip at 537aa0d.

Builds of openDog V3

0 reviewed

No reviewed builds of openDog V3 yet.

A build log records the evidence (photos, a video, your repository), what the build cost, how long it took and what you changed. Each one is checked by Motari (until a maintainer claims this page) before it shows here, and reviewed builds count toward the reproducibility score.

Sources and provenance

Sources

Last push to XRobots/openDogV3: 2023-03-19 (checked 2026-10-01)

Related links

How this page was made

Assembled from public sources on 2026-06-04, not yet reviewed by the maintainer. Each figure links to where it is stated; a value the sources do not state reads "not published". Last source review: source BOM.ods 537aa0d.

Original files stay intact and separately licensed; Motari adds only the summary on this page. Maintainer? Request a correction or removal.

Badge for the README

Maintain openDog V3? Show its reproducibility score in the project's README. The badge links back to this page and updates with the score.

Badge: reproducibility 68/100

Markdown
[![Motari reproducibility score for openDog V3](https://motari.io/api/v1/badge/opendog-v3)](https://motari.io/r/opendog-v3)
HTML
<a href="https://motari.io/r/opendog-v3"><img src="https://motari.io/api/v1/badge/opendog-v3" alt="Motari reproducibility score for openDog V3" height="20"></a>

Not fully met yet: wiring diagram, build instructions (partial). The score is read from the project's own sources, so publishing what is missing is what raises it. A score of 90 or more needs a reviewed build. How the score is computed