Auto-assembled, not yet reviewed

OpenMower

Open-hardware brain that upgrades cheap robot mowers to RTK-GPS autonomy.

Reproducibility60/100Partial source coverage, unverifiedCADBOMWIREFWBUILDLICREPHow it is computed
No 3D model yet
No ready source-derived model
OpenMower retrofits a commercial robot mower, and no 3D model of the mower is published. The only open CAD is the mainboard KiCad project in xtech/hw-openmower-yardforce.
No 3D model generated yet

About OpenMower

OpenMower is an open-hardware project that retrofits compatible off-the-shelf robotic mowers, especially YardForce and SUMEC-class machines, with a custom OpenMower hardware kit, RTK GPS and open firmware for centimeter-accurate mowing without a perimeter wire. The docs list the required mower, the OpenMower hardware kit, rover GPS, Raspberry Pi CM4 and optional base-station parts; the repository README says the current docs estimate is about EUR 700, excluding the donor mower and the RTK base station. No 3D model of the mower or the retrofit is published. The mainboard hardware lives in the xtech/hw-openmower-* repositories under CC BY 4.0.

Licenses

Hardware
CC-BY-4.0
Software
GPL or MIT, per repository
Docs
CC-BY-NC-SA-4.0NC

Degrees of freedom

2 DoF

No per-group breakdown has been sourced yet.

Robotic mowersource

How to build OpenMower

5 steps

Steps marked Motari summary condense the linked source; follow the source for exact instructions. Upstream step marks a step taken from the linked guide.

  1. Get a compatible mower

    Source a supported off-the-shelf mower (YardForce / SUMEC-class) per the openmower.de compatibility checklist.

    Upstream stepgithub.com/ClemensElflein/OpenMower/blob/715b3ddc75202e321a1...

  2. Build the mainboard

    Fabricate or order the OpenMower mainboard PCB and gather the RTK GPS and parts from the shopping list.

    Upstream stepopenmower.de/latest/docs/knowledge-base/getting-started/shop...

  3. Retrofit the electronics

    Disassemble the mower, remove the stock mainboard and fit the OpenMower mainboard in its place, reconnecting the mower's connectors and mounting the GPS antenna holder per the robot-specific guide.

    Motari summaryopenmower.de/latest/docs/getting-started

  4. Flash firmware and software

    Flash the open firmware and install the Raspberry Pi software stack.

    Motari summaryopenmower.de/latest/docs/getting-started

  5. Set up RTK and mow

    Set up RTK corrections from your own base station or an NTRIP service, configure the parameters, then record your mowing areas and start mowing.

    Motari summaryopenmower.de/latest/docs/getting-started
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.

OpenMower bill of materials

6 rows

Cost to build

€700EURestimate
  • shopping list estimate excluding the donor mower and RTK base station€700estimate

In the source currency, as read on 2026-09-30. Not converted, and not checked against current vendor prices: none of these is a Motari-verified checkout total.

OpenMower parts, as the source lists them (read 2026-06-07). Prices are the source's, not checked against vendors.

OpenMower bill of materials
PartQtySpecSourceConfidence
Compatible robot mowerDonor mower to modify; YardForce Classic 500(B) is the best-supported documented target
1YardForce Classic 500(B) or compatible mower
Amazon link from the project's BOM / compatible mower vendorprice not listedopenmower.de shopping-list line 20; getting-started lines 69-71; compatible-mowers lines 11-20
high
OpenMower hardware kitElectronics mounted inside robot and charging station; v2 hardware contact is listed via Discord
1Core Board, model-specific Carrier Board, 3x xESC motor-controller boards
OpenMower community / @Apehaenger on Discord; v1 Vermut shop listedprice not listedopenmower.de shopping-list line 21; getting-started lines 73-83
high
RTK GPS rover receiver and antennaRobot positioning system; rover GPS mounted on the mower
1Ardusimple RTK2B GPS + antenna; UM9XX alternatives noted
ArduSimple / alternative UM9XX vendorsprice not listedopenmower.de shopping-list line 22; getting-started lines 86-90
high
Raspberry Pi Compute Module 4 with WiFiRuns the ROS navigation stack on the robot
1CM4 with WiFi, 2GB+ RAM for runtime, 4GB+ for development, 16GB+ storage
RPi Locator / Raspberry Pi resellersprice not listedopenmower.de shopping-list line 23; architecture lines 20-24
high
microSD cardRequired only for Raspberry Pi CM4 Lite builds
116GB minimum, 32GB recommended
Amazon link from the project's BOM or local hardware storeprice not listedopenmower.de shopping-list line 24
high
Optional RTK base station kitOnly needed when no external NTRIP correction service is available
0Raspberry Pi + SD card + power supply, Ardusimple RTK2B GPS + antenna
Raspberry Pi / ArduSimpleprice not listedopenmower.de shopping-list lines 30-41; architecture lines 34-36
high

Rows from the source's own parts list 12

README.md@715b3ddmarkdown

Source rowQtyPrice and vendorLine
OpenMower docs cost scope
about EUR 700 excluding mower and RTK base station
vendor not listed~EUR 700 excluding mower and RTK base station
L71

content/en/docs/Knowledge-Base/shopping-list/index.md@dd61a27markdown

Source rowQtyPrice and vendorLine
OpenMower required robot parts
mower x1; hardware kit x1; RTK rover x1; CM4 x1; microSD x1
vendor not listedno price listed
L16
OpenMower donor mower row
1
vendor not listedno price listed
L20
OpenMower hardware kit row
1
vendor not listedno price listed
L21
OpenMower RTK rover row
1
vendor not listedno price listed
L22
OpenMower CM4 row
1
vendor not listedno price listed
L23
OpenMower storage and optional USB accessories
microSD x1; optional accessories x0
vendor not listedno price listed
L24
OpenMower optional RTK base station
base station bundle x1 optional
vendor not listedno price listed
L30

content/en/docs/Knowledge-Base/compatible-mowers/index.md@dd61a27markdown

Source rowQtyPrice and vendorLine
OpenMower YardForce compatibility
compatible mower family
vendor not listedno price listed
L11
OpenMower SABO John Deere compatibility
compatible mower family
vendor not listedno price listed
L28
OpenMower universal board compatibility
universal board option
vendor not listedno price listed
L57

content/en/docs/Knowledge-Base/architecture/index.md@dd61a27markdown

Source rowQtyPrice and vendorLine
OpenMower system architecture hardware roles
CM4, xCore, RTK base station
vendor not listedno price listed
L20

OpenMower source files

5 files

Files stay in the upstream repository under their own licenses; these links open them there.

OpenMower 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.

No 3D model has been generated from the project's files yet.

Builds of OpenMower

0 reviewed

No reviewed builds of OpenMower 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 ClemensElflein/OpenMower: 2026-09-03 (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: 2026-06-07 OpenMower docs shopping list.

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

Badge: reproducibility 60/100

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

Not fully met yet: cad / mesh present, bom evidence (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