Asimov 1 open-source 25-DoF humanoid robot, 3D render from asimov_1.urdf, the project's simulation model

Asimov 1

Menlo Research's 1.2 m, 25-DoF open-source humanoid, sold as a DIY kit.

Start the build

What it is

Asimov 1 is a 1.2 m, 35 kg bipedal humanoid from Menlo Research with 25 powered joints: 6 per leg (a parallel RSU ankle driven by two actuators), 5 per arm, a waist yaw and a 2-DoF neck, driven by five EC-A actuator models, a Radxa CM5 motion-control board, a Raspberry Pi 5 head computer and a 13S4P lithium-ion pack. The repository holds per-part STEP files for seven subassemblies (7075 aluminium, MJF PA12, 316L and off-the-shelf parts) with bearing, thread and heat-insert drawings, a full-body STEP assembly of about 369 MB stored in Git LFS, KiCad sources for the motion-control, power-distribution and Raspberry Pi HAT boards plus an EasyEDA Pro head board, cable lists, and a MuJoCo MJCF and URDF with 25 STL meshes in which the neck joints are fixed. Hardware is CERN-OHL-S-2.0 and software GPL-2.0, but the repo contains almost no software: firmware images are shared on request, locomotion training code is in menloresearch/cyclotron (BSD-3-Clause, formerly isaac_asimov), and the full BOM is gated behind a request form. Menlo's Python menlo-sdk (Apache-2.0, published on PyPI) drives the robot from a host computer. Menlo sells the unassembled DIY kit for $20,000 and estimates a 20-hour build, with a step-by-step manual on docs.menlo.ai. It succeeds the legs-only Asimov v0.

Licenses

Hardware
CERN-OHL-S-2.0
Software
GPL-2.0
Docs
Not published

Degrees of freedom

25 DoF arms 10legs 12neck 2waist 1

Breakdown source

Bipedal humanoidParallel ankleFull bodysource

Auto-assembled, not yet reviewed

Source record

Sources
1.2k stars, last push 2026-09-28
HW license
CERN-OHL-S-2.0
Cost
$20,000vendor kit, Asimov 1 DIY Kit, unassembled (Batch 4); order with a 499 USD deposit; final price may vary by destination country based on tariffs and shipping
Lifecycle
Active
Engine
v3.1.1
Checked
Model
asimov_1.urdf@35ae7b3the project's simulation model in menloresearch/asimov-1, not its build CADrendered 2026-10-02
Envelope
424 × 1254 × 257 mmas in the simulation model, default pose

Maintain Asimov 1? Claim this page to correct it.

Parts and cost

12 rows

Cost to build

$20,000USDvendor kit
  • Asimov 1 DIY Kit, unassembled (Batch 4); order with a 499 USD deposit; final price may vary by destination country based on tariffs and shipping$20,000vendor kit

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.

Asimov 1 parts, as the source lists them. Prices are the source's, not checked against vendors.

Asimov 1 bill of materials
PartQtySpecSourceConfidence
Asimov 1 DIY KitOfficial vendor kit, shipped unassembled; the full itemized BOM is only available through a request form
1All BOM components, power supply and cabling, spare parts, edge, motion-control, network and power-distribution boards, camera, IMUs, mic, speaker; tools, hands, lidar, 360 camera and 4G/5G modules not included
Menlo Research$20,000 DIY kit price with a $499 deposit; final price may vary by destination countrymenlo.ai order page (Batch 4) and menloresearch/asimov-1 README.md lines 50 and 55-62
high
EC-A6416-P2-25 actuatorHip pitch (x2) and waist yaw
340 Nm rated, 120 Nm peak
EC-A series; the asimov-v0 README names Encos as maker of these modelsincluded in DIY kit; separate price not listeddocs.menlo.ai Asimov 1 mechanical system tour, actuator table
high
EC-A5013-H17-100 actuatorHip roll (x2) and shoulder pitch (x2)
430 Nm rated, 90 Nm peak
EC-A series; the asimov-v0 README names Encos as maker of these modelsincluded in DIY kit; separate price not listeddocs.menlo.ai Asimov 1 mechanical system tour, actuator table
high
EC-A3814-H14-107 actuatorHip yaw (x2) and shoulder yaw (x2)
420 Nm rated, 60 Nm peak
EC-A series; the asimov-v0 README names Encos as maker of these modelsincluded in DIY kit; separate price not listeddocs.menlo.ai Asimov 1 mechanical system tour, actuator table
high
EC-A4315-P2-36 actuatorKnee (x2) and shoulder roll (x2)
425 Nm rated, 75 Nm peak
EC-A series; the asimov-v0 README names Encos as maker of these modelsincluded in DIY kit; separate price not listeddocs.menlo.ai Asimov 1 mechanical system tour, actuator table
high
EC-A4310-P2-36 actuatorParallel-ankle A and B (x4), elbow (x2), wrist yaw (x2) and neck yaw/pitch (x2)
1012 Nm rated, 36 Nm peak; ankle A/B joint figures differ through the linkage
EC-A series; the asimov-v0 README names Encos as maker of these modelsincluded in DIY kit; separate price not listeddocs.menlo.ai Asimov 1 mechanical system tour, actuator table
high
Robot Processing Unit (RPU)Radxa CM5 on the Menlo motion-control carrier board with a Power Distribution Board stacked above; KiCad sources in the repo
1Radxa CM5; LSM6DSV IMU; 6 SPI-CAN ports, 2 USB 2.0, 1 Gbps Ethernet, I2C; XT90 (2+2) power input
Menlo design; Radxa CM5 moduleincluded in DIY kit; separate price not listedmenloresearch/asimov-1 electrical/README.md and docs.menlo.ai Asimov 1 electrical system tour
high
Head Compute UnitMedia, networking and edge services computer in the head
1Raspberry Pi 5 with Head Board (buck converters, audio IC) and Media HAT (button, LED, buzzer)
Raspberry Pi; Menlo boardsincluded in DIY kit; separate price not listedmenloresearch/asimov-1 electrical/README.md and docs.menlo.ai Asimov 1 electrical system tour
high
Battery packLithium-ion pack with protection circuit module
113S4P INR18650, 46.8 V nominal, 10.5 Ah typical, 491.4 Wh, about 2 kg
Menlo DIY kit contentsincluded in DIY kit; separate price not listeddocs.menlo.ai Asimov 1 electrical system tour, battery table
high
Sensors and media setHead and torso sensing and audio
12 MP monocular camera, 6-axis IMU, stereo microphone array, 10 W 4 ohm speaker
Menlo DIY kit contentsincluded in DIY kit; separate price not listedmenloresearch/asimov-1 README.md lines 32-33 and docs.menlo.ai Asimov 1 electrical system tour
high
Actuator cable setPre-made XT30 (2+2) leads; some joins are soldered or WAGO-spliced after assembly
32XT30 (2+2) female leads, 100 to 600 mm
Menlo DIY kit contentsincluded in DIY kit; separate price not listedmenloresearch/asimov-1 electrical/wiring/motor-wires.csv lines 2-33
high
Fabricated and off-the-shelf part filesPer-part STEP files across 7 subassemblies; per-part quantities are in the gated BOM, not in the repo
143 7075 aluminium, 37 MJF PA12 and 18 316L part files plus 67 off-the-shelf part models
fabricate from repo STEP files or buy the DIY kitincluded in DIY kit; separate price not listedmenloresearch/asimov-1 mechanical/ASV1 tree at commit 35ae7b3
high

Rows from the source's own parts list 10

README.md@35ae7b3markdown

Source rowQtyPrice and vendorLine
Asimov 1 DIY Kit
1
Menlo Research$20,000
L50
DIY kit hardware contents
vendor not listedno price listed
L59
DIY kit compute contents
vendor not listedno price listed
L60
DIY kit sensor contents
vendor not listedno price listed
L61

Asimov 1 mechanical system tour, actuator tablehtml

Source rowQtyPrice and vendorLine
EC-A6416-P2-25
3 (counted from the per-ID actuator table on the same page)
vendor not listedno price listed
L31
EC-A5013-H17-100
4 (counted from the per-ID actuator table on the same page)
vendor not listedno price listed
L31
EC-A3814-H14-107
4 (counted from the per-ID actuator table on the same page)
vendor not listedno price listed
L31
EC-A4315-P2-36
4 (counted from the per-ID actuator table on the same page)
vendor not listedno price listed
L31
EC-A4310-P2-36
10 (counted from the per-ID actuator table on the same page)
vendor not listedno price listed
L31

Asimov 1 order pagehtml

Source rowQtyPrice and vendorLine
Asimov 1 DIY Kit (Batch 4)
1
Menlo Research$20,000
L1

How to build

6 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. Sort the kit by module

    Set out labelled trays for the left leg, right leg, pelvis, left arm, right arm, torso and head, keeping left and right parts apart, and check each module against the manual checklist before building.

    Upstream stepdocs.menlo.ai/asimov/1/build/assembly-preparations

  2. Prepare battery and electronics

    Fit the battery into its enclosure with the charge port and switch, set up the Head Compute Unit and the RPU, then flash the Raspberry Pi 5 with Raspberry Pi Imager and the Radxa CM5 over USB-C in MaskROM mode, using images Menlo shares on request.

    Motari summarydocs.menlo.ai/asimov/1/build/assembly-preparations/software-...

  3. Program actuator IDs

    In Asimov Manager, connect one actuator at a time to the setup connector and write the ID from its sticker (1 to 25); never program with the harness connected. Menlo allows about an hour and a half.

    Upstream stepdocs.menlo.ai/asimov/1/build/assembly-preparations/assign-ac...

  4. Assemble legs, pelvis, arms and torso

    Build each leg (14 steps), the pelvis (9), each arm (14) and the torso with head, battery and covers (10), checking fit dry before applying threadlocker to bolts.

    Motari summarydocs.menlo.ai/asimov/1/build/assembly-steps

  5. Finish and check the assembly

    Confirm both legs are on the pelvis, both arms on the torso, the head and RPU installed, covers secured, no cable trapped, and the battery connected to the RPU with the robot still powered off and supported.

    Upstream stepdocs.menlo.ai/asimov/1/build/assembly-steps/finish-assembly

  6. Calibrate actuators and first start

    With the firmware stopped and the robot supported, run the Liveness Check so all 25 actuators answer without faults, record zero positions at the home pose, then continue to First Start.

    Upstream stepdocs.menlo.ai/asimov/1/operate/setup/calibrate-actuators
Print timenot published
Assembly time20 h

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

How reproducible

How confidently this design builds into a working robot, from what its sources publish: each criterion's points, quality tier and evidence.

80/100Strong source coverage, unverified

Engine v3.1.1 at 35ae7b3, 2 items reviewed by hand

How this score is computed

Files and sim

14 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.

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 sim-model/urdf/asimov_1.urdf at 35ae7b3, the project's simulation model in menloresearch/asimov-1, not its build CAD.

Builds

0 reviewed

No reviewed builds of Asimov 1 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

Where the facts come from

Last push to menloresearch/asimov-1: 2026-09-28 (checked 2026-10-02)

Related links

How this page was made

Assembled from public sources on 2026-09-30, 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: 2026-09-30 menloresearch/asimov-1@35ae7b3 README, HARDWARE-LICENSE.txt, SOFTWARE-LICENSE.txt, tree.

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 Asimov 1? 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 Asimov 1](https://motari.io/api/v1/badge/asimov-1)](https://motari.io/r/asimov-1)
HTML
<a href="https://motari.io/r/asimov-1"><img src="https://motari.io/api/v1/badge/asimov-1" alt="Motari reproducibility score for Asimov 1" 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