xrobots/opendog · spec sheet
James openDog V3 specs
Large 3D-printed hobby quadruped using brushless motors with ODrive controllers and printed cycloidal gearboxes; CAD, code and BOM are published.
Class
Quadruped
Status
Orphaned
Availability
DIY build
Country
United Kingdom
Level
L1 Compiled
01
Media
none on recordNo licensed media on record for James openDog V3 yet. We only show our own renders from public URDF/MJCF, Wikimedia Commons files with their exact license, images from the robot’s own open repositories, and the maker’s official videos. No press images are hotlinked. Have an openly licensed image or an official video? Send it with the correction form.
02
Specifications
2/12 fields sourced| Heightspecs.heightCm | unsourced |
|---|---|
| Massspecs.massKg | unsourced |
| Degrees of freedomspecs.dof | unsourced |
| Payloadspecs.payloadKg | unsourced |
| Top speedspecs.speedMps | unsourced |
| Runtimespecs.runtimeMin | unsourced |
| Battery capacityspecs.batteryWh | unsourced |
| Pricespecs.priceUsd | unsourcedNo total in the repo: BOM.ods has no prices. A ~$2000 figure circulates but is not stated in the repo. |
| Actuatorsspecs.actuators | Brushless motors + ODrive, 3D-printed cycloidal drives, AS5047 encoders |
| Computespecs.compute | unsourced |
| Sensorsspecs.sensors | unsourced |
| Year introducedyear | 2021 |
| Licenselicense.hw / .sw / .docs | Hardware: MITSoftware: MIT |
Note · One-person YouTube project; repo last pushed Mar 2023. City omitted (not public on GitHub). BOM.ods lists parts and links but no prices.
70 / 100Open hardware
| Artifact | Public | Weight | Points |
|---|---|---|---|
| CADopenness.cad | yes | 25 | 25 |
| Bill of materialsopenness.bom | yes | 20 | 20 |
| Sim model (URDF/MJCF)openness.sim | no | 20 | 0 |
| Firmwareopenness.firmware | yes | 15 | 15 |
| Softwareopenness.software | yes | 10 | 10 |
| Trained policiesopenness.policies | no | 10 | 0 |
| score = Σ weight × public | 70 | ||
BOM lines
44
Parts (qty)
1,794
Priced BOM
—
Fab parts
12
Print time
—
Material
—
Build steps
14
Est. assembly
—
Safety steps
4
Vendors
12
BOM by category · USD from priced lines
| Category | Lines | Qty | USD |
|---|---|---|---|
| Fasteners | 10 | 536 | — |
| Structure | 9 | 616 | — |
| Electronics | 6 | 20 | — |
| Power | 6 | 7 | — |
| Other | 4 | 578 | — |
| Sensors | 3 | 15 | — |
| Cabling | 3 | 8 | — |
| Compute | 2 | 2 | — |
| Actuators | 1 | 12 | — |
Offers in CN · GLOBAL · US from 12 vendors
Subsystems · assembly groups
| Group | Steps | Min | Safety |
|---|---|---|---|
| Preparation | 1 | — | — |
| Fabrication | 2 | — | — |
| Drives | 2 | — | — |
| Legs | 2 | — | — |
| Electronics | 2 | — | 1 |
| Bring-up | 4 | — | 3 |
| Remote | 1 | — | — |
Fabrication: FDM print ×12
Firmware
- Targets
- Teensy 4.1 (openDogV3.ino, Arduino/Teensyduino), Teensy LC (Remote.ino), ODrive v3.6 x6 (stock firmware, configured with odrivetool)
- Repo
- github.com/XRobots/openDogV3
- Calibrate
- Per ODrive axis: motor calibration, AS5047P absolute SPI setup (`encoder.config.mode = ENCODER_MODE_SPI_ABS_AMS`, `cpr = 2**14`, CS pin), `AXIS_STATE_ENCODER_OFFSET_CALIBRATION`, `pre_calibrated = True`, save; vel_limit and vel_limit_tolerance = math.inf. Then tune the offSetXY constants in openDogV3.ino until menu mode 3 puts every joint at 45 degrees.
- Notes
- Teensy talks to ODrives over ASCII serial (Serial1-6, 115200) with the ODriveArduino library; remote link is NRF24L01 (addresses '00001'/'00002'). Code/openDogV3_experimental_stability adds MPU6050 IMU feedback. No ROS, URDF or simulation is published.
Caveats · stated by the package
- No written assembly instructions: the build is only shown in the YouTube playlist. The drive, leg and body steps here only restate BOM notes and code; sequence and fits must come from the videos and the STEP assembly.
- No STL set: printable parts must be exported from the STEP files. Only the cycloidal internals and foot mould have their own files.
- BOM.ods has no prices. The only price is a note ('$70 for 400' small bearings); the robots.ts '~$2000' figure is not in the repo. Most links are UK retailers (eBay UK, Amazon UK, CEF, Simply Bearings) or AliExpress; eBay/AliExpress listings expire.
- Three Cool Components links (Teensy 4.1, Teensy LC, MPU6050) returned 404 on 2026-09-25. PJRC lists Teensy LC as discontinued and not recommended for new designs.
- Links point at ODrive's 'latest' docs, which now cover the newer ODrive firmware; openDog uses ODrive v3.6 with the 0.5.x odrivetool API. Motor pole pairs, current limits other than the 20 A set in code, and ODrive config files are not published.
- BOM inconsistencies: leg screws '18 per leg' but 56 listed; the remote code drives a 20x4 LCD but only one (16x2) LCD is listed; the remote battery is not listed; the CAD shows 2020 aluminium extrusion (stand) that is not in the BOM; knee pulleys and wiring/connectors for the high-current side are not listed.
- The author says the BOM is 'probably complete'. The repo was last updated March 2023; robots.ts marks the project orphaned.
- No torque values, print times or filament totals are published.
Package xrobots/opendog@0.1.0 · upstream XRobots/openDogV3@537aa0db8539bf255b072e4a1d7da38d08084ba8 (2023-03-19); BOM.ods, CAD/*.stp (assembly STEP exported 2022-03-20) and Code/ as of that commit; build videos in the linked YouTube playlist (not transcribed) · 12 package sources
05
Models, repositories, links
4 links- Repogithub.com/XRobots/openDogV3github.com
- SiteXRobots.co.ukxrobots.co.uk
- Docsgithub.com/XRobots/openDogV3github.com
- Videoyoutube.com/playlist?list=PLpwJoq86vov8uTgd8_WNgBHFpDYemO-OJyoutube.com
06
Videos
3 tagged · 0 from the maker's channel07
News and papers
0 stories · 0 papersNews mentioning openDog V3
The news feed is not reachable right now; this page regenerates every 30 minutes.
Papers using openDog V3
The papers feed is not reachable right now; this page regenerates every 30 minutes.
08
Sources
last checked 2026-09-25- [1]openDogV3 repo (MIT, BOM)github.com/XRobots/openDogV3checked 2026-09-24
- [2]openDogV3 BOM.ods (no prices)github.com/XRobots/openDogV3/blob/main/BOM.odschecked 2026-09-25
- [3]Hackaday: openDog V3 (Dec 2021)hackaday.com/2021/12/18/opendog-version-3-is-ready-to-go-walkies/checked 2026-09-24
- [4]3D Printing Industry: V3 development3dprintingindustry.com/news/james-bruton-begins-work-on-v3-of-his-open-source-3d-printed-robotic-dog-196644/checked 2026-09-24
09
Suggest a correction
10
Related
Nearest by size (height, mass)
Needs a sourced height or mass before size neighbours can be computed.
11
Cite this page
humanoidrobots.systems. “James openDog V3 specs.” Hyperspawn, data revision 2026-10-08. https://humanoidrobots.systems/xrobots/opendog
Machine-readable: /data.json (record xrobots/opendog).