Auto-assembled, not yet reviewed

K-Scale K-Bot

Open-source full-size modular humanoid from K-Scale Labs, which shut down in November 2025.

Defunct. The organization behind this robot has shut down; expect no support, parts or updates.

K-Scale Labs shut down in November 2025 and refunded preorders.

Lifecycle source

Reproducibility80/100Strong source coverage, unverifiedCADBOMWIREFWBUILDLICREPHow it is computed
K-Scale K-Bot open-source 20-DoF humanoid robot, 3D render from robot.mjcf
main assembly 3D · robot.mjcf

About K-Scale K-Bot

K-Bot is an open-source humanoid robot from K-Scale Labs aimed at making capable humanoids accessible. It is built from COTS components on a 48V CAN-bus actuator architecture with a modular, repairable design: hands swap via a lens-mount interface, the head detaches, and the whole robot presents largely as a single USB device. The repository publishes the mechanical CAD (Onshape), electrical design docs, and a software stack split across submodules for the operating system (kos-kbot), simulation (ksim-kbot), and inference (kbot-inference). K-Scale Labs shut down in November 2025 and refunded preorders, so no developer kit is sold; the repositories remain public.

Licenses

Hardware
CERN-OHL-S-2.0
Software
GPL-3.0per the README; the LICENSE file is MIT
Docs
Not published

Degrees of freedom

20 DoF RS00 2RS02 6RS03 8RS04 4

Breakdown source

Humanoidsource

How to build K-Scale K-Bot

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. Review the CAD and docs

    Study the Onshape CAD and the K-Bot mechanical and electrical pages, BOM spreadsheet, assembly guide and wiring PDF in the kscalelabs/docs repository (docs.kscale.dev no longer resolves).

    Motari summarygithub.com/kscalelabs/docs/tree/master/docs/robots/k-bot

  2. Source actuators and parts

    K-Scale Labs shut down in November 2025, so no developer kit is sold. Order the parts in the BOM spreadsheet, including 20 Robstride actuators (2 RS00, 6 RS02, 8 RS03, 4 RS04), and have the fabricated parts CNC machined from the Onshape files.

    Motari summarygithub.com/kscalelabs/docs/tree/master/docs/robots/k-bot

  3. Assemble the modular body

    Build the modular frame; hands attach via the lens-mount interface and head detaches for easy repair/upgrade.

    Upstream stepgithub.com/kscalelabs/kbot/blob/76aba70e3372fecf3583ed6dbe5f...

  4. Set up the Raspberry Pi

    Flash Raspberry Pi OS (64-bit) for the Raspberry Pi 5, then install the robstride, firmware and kbot_deployment repositories and download the policies.

    Upstream stepgithub.com/kscalelabs/docs/blob/d4ca00ddc760197661d66495d079...

  5. Calibrate and run policies

    Set up the CAN interfaces, scan for all 20 actuators, zero them with the robstride tool, then run the standing and walking policies from kbot_deployment (public alpha).

    Motari summarygithub.com/kscalelabs/docs/tree/master/docs/robots/k-bot
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.

K-Scale K-Bot bill of materials

11 rows

Cost to build

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

K-Scale K-Bot parts, as the source lists them. Prices are the source's, not checked against vendors.

K-Scale K-Bot bill of materials
PartQtySpecSourceConfidence
Robstride RS00 actuator setSmall K-Bot actuators from the docs actuator table.
25 Nm rated, 14 Nm peak for 10 seconds, 0.31 kg, 10:1 gear ratio
Robstrideprice not listedK-Scale docs actuator table
high
Robstride RS02 actuator setArm and ankle class actuators from the docs actuator table.
66 Nm rated, 17 Nm peak for 10 seconds, 0.38 kg, 7.75:1 gear ratio
Robstrideprice not listedK-Scale docs actuator table
high
Robstride RS03 actuator setShoulder/hip class actuators from the docs actuator table.
820 Nm rated, 60 Nm peak for 10 seconds, 0.88 kg, 9:1 gear ratio
Robstrideprice not listedK-Scale docs actuator table
high
Robstride RS04 actuator setHighest-torque hip/knee class actuators from the docs actuator table.
440 Nm rated, 120 Nm peak for 10 seconds, 1.42 kg, 9:1 gear ratio
Robstrideprice not listedK-Scale docs actuator table
high
Torso fabricated parts setKD-B torso fabricated hardware summarized from the public BOM spreadsheet.
10CNC/fabricated torso subsystem parts; details in Kbot_BOM.xlsx and Onshape public release
fabrication you sourceprice not listedK-Scale docs BOM spreadsheet and fabricated parts zip
med
Arm fabricated parts setKD-C arm fabricated hardware summarized from the public BOM spreadsheet.
18CNC/fabricated arm subsystem parts; details in Kbot_BOM.xlsx and Onshape public release
fabrication you sourceprice not listedK-Scale docs BOM spreadsheet and fabricated parts zip
med
Leg fabricated parts setKD-D leg and foot fabricated hardware summarized from the public BOM spreadsheet.
44CNC/fabricated leg/foot subsystem parts; details in Kbot_BOM.xlsx and Onshape public release
fabrication you sourceprice not listedK-Scale docs BOM spreadsheet and fabricated parts zip
med
Head fabricated parts setKD-E head fabricated hardware summarized from the public BOM spreadsheet.
7Head subsystem fabricated parts; details in Kbot_BOM.xlsx and Onshape public release
fabrication you sourceprice not listedK-Scale docs BOM spreadsheet and fabricated parts zip
med
Battery enclosure fabricated parts setKD-F battery enclosure fabricated hardware summarized from the public BOM spreadsheet.
9Battery enclosure subsystem fabricated parts; details in Kbot_BOM.xlsx and Onshape public release
fabrication you sourceprice not listedK-Scale docs BOM spreadsheet and fabricated parts zip
med
12 Ah NCM battery pack with BMSDocs specify the current K-Bot battery chemistry, capacity, cell voltage and BMS current protection.
112 Ah NCM pack, 4 V cells, BMS current protection limit 50 A; pack space 135 x 180 x 65 mm
battery pack you sourceprice not listedK-Scale docs battery section
high
Powerboard and 48 V + CAN wiring systemElectrical docs describe main fused battery connector, powerboard requirements, CAN/power links and Raspberry Pi 5 power header.
180 A fused main battery connector, BMS wires, power button, e-stop, power resistor, 48 V + CAN lines, 24 V lines/header, Pi 5 buck converter
K-Scale / builder wiring harnessprice not listedK-Scale electrical docs overview
med

Rows from the source's own parts list 6

docs/robots/k-bot/mechanical.md@d4ca00dmarkdown

Source rowQtyPrice and vendorLine
K-Bot BOM spreadsheet and fabricated parts source
BOM spreadsheet plus fabricated subsystem counts summarized in Motari rows
K-Scale docs / Onshape public releaseno price listed
L16
K-Bot Robstride actuator set
RS00 x2; RS02 x6; RS03 x8; RS04 x4
Robstrideno price listed
L37
12 Ah NCM battery pack with BMS
one battery pack
builder-sourced battery packno price listed
L64

docs/robots/k-bot/electrical.md@d4ca00dmarkdown

Source rowQtyPrice and vendorLine
K-Bot powerboard and wiring harness
one robot wiring/power system
K-Scale electrical docsno price listed
L18

.gitmodules@76aba70gitmodules

Source rowQtyPrice and vendorLine
kbot to ksim-kbot submodule link
K-Scale kbot repositoryno price listed
L4

.gitmodules@e7681a1gitmodules

Source rowQtyPrice and vendorLine
ksim-kbot to kscale-assets submodule link
K-Scale ksim-kbot repositoryno price listed
L1

K-Scale K-Bot source files

6 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.

K-Scale K-Bot in simulation

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

The 3D specimen on this page is converted from kbot-v2/robot.mjcf at 4aa9ff9.

Builds of K-Scale K-Bot

0 reviewed

No reviewed builds of K-Scale K-Bot 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 kscalelabs/kbot: 2025-11-07 (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-reviewed 2026-06-08.

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

Badge: reproducibility 80/100

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

Not fully met yet: 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