How to build Asimov 1
25-DoF humanoid robot · Expert
Asimov 1 is a 1.2 m, 35 kg open-source humanoid from Menlo Research with 25 joints, EC-A actuators, a Radxa CM5 controller and a $20,000 DIY kit.
Research-grade: machining, motor drivers and control theory.
Our estimate, part-time
$20,000 for the unassembled DIY kit (Menlo listing); self-sourcing cost is not published
CERN-OHL-S-2.0
What is Asimov 1?
Asimov 1 is Menlo Research's open humanoid: 1.2 m tall, about 35 kg, with 25 powered joints. Each leg has six, including a parallel ankle worked by two actuators; each arm has five; and there's a waist yaw plus a two-axis neck.
Menlo publishes nearly everything: per-part STEP files for seven subassemblies in 7075 aluminium, MJF PA12 and 316L steel, KiCad sources for the motion-control, power and Pi HAT boards, cable lists, and a MuJoCo model. The hardware is CERN-OHL-S-2.0, a strongly reciprocal licence.
You can fabricate parts yourself from the files or buy the unassembled DIY kit, which Menlo lists at $20,000 with a $499 deposit.
Asimov 1 specifications
- Height / mass
- ≈1.2 m / ≈35 kg
- DoF
- 25 (12 legs, 10 arms, 1 waist, 2 neck)
- Actuators
- Five EC-A series models, 12–40 Nm rated
- Compute
- Radxa CM5 motion board + Raspberry Pi 5 head
- Battery
- 13S4P 18650, 46.8 V nominal
Figures as published by the project. See Sources below.
Bill of materials
| Part | Qty | Notes |
|---|---|---|
| EC-A6416 / 5013 / 3814 / 4315 / 4310 actuators | 25 total | |
| Robot Processing Unit (Radxa CM5 carrier with IMU and 6 SPI-CAN ports) | 1 | |
| Raspberry Pi 5 with head board | 1 | |
| 13S4P INR18650 battery pack with protection | 1 | |
| Camera, IMU, stereo audio | — | Head and torso sensing |
| Aluminium, PA12 and steel fabricated parts | — | From the repo's STEP files |
Where's the full bill of materials?
The full BOM, with exact quantities and vendors, lives in the project's own files. Prices change often, so treat $20,000 as a ballpark from the project. Start at the project repository.
Tools you'll need
- Metric hex and torque drivers
- Soldering iron for XT30 joins
- Labelled parts trays
- A PC with MuJoCo for testing
Step-by-step build overview
Electronics & wiring overview
The motion-control board talks to actuators over six SPI-to-CAN channels, and the head Pi handles media and networking. Actuator power runs over XT30 (2+2) leads from the 46.8 V pack.
Software
A MuJoCo MJCF and URDF are in the repo for simulation and policy work. Board firmware is published alongside the KiCad sources.
Tips from the bench
- ☕ The full STEP assembly is about 369 MB in Git LFS, so install git-lfs before cloning.
- ☕ Check the release notes before ordering parts; fabricated files change between batches.
Asimov 1 FAQ
How much does Asimov 1 cost?
Menlo lists the unassembled DIY kit at $20,000. A self-sourced build cost isn't published.
How tall is Asimov 1?
About 1.2 m, weighing roughly 35 kg.
What license is it under?
Hardware is CERN-OHL-S-2.0, which requires derived hardware to stay open.
Sources
Written by Bots n' Beans from the project's own documentation. Check the sources for the latest revision before you buy parts.
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