How to build ODRI Open Robot Actuator Hardware (Solo / Bolt)
12-DoF four-legged robot dog · Expert
The Open Dynamic Robot Initiative's BSD-3 actuator: two T-Motor 4004 motors, a two-stage belt drive, an AEDT-9810 encoder and BLMC micro-driver electronics.
Research-grade: machining, motor drivers and control theory.
Our estimate, part-time
No total is published
BSD-3-Clause
What is ODRI Open Robot Actuator Hardware (Solo / Bolt)?
The Open Dynamic Robot Initiative (ODRI) designed one torque-controllable actuator module and built its legged robots, Solo and Bolt, from it.
Each module pairs T-Motor Antigravity 4004 300 kV brushless motors with a two-stage Synchroflex AT3 timing-belt reduction. A Broadcom AEDT-9810 optical encoder reads a PWB codewheel.
The repo publishes STEP and STL files, drawings, micro-driver electronics, wiring images and assembly docs under BSD-3-Clause. Suppliers are listed but there's no total cost.
ODRI Open Robot Actuator Hardware (Solo / Bolt) specifications
- Motor
- T-Motor Antigravity 4004 300 kV
- Transmission
- 2-stage AT3 timing belt
- Encoder
- AEDT-9810 + 625 CPR codewheel
- License
- BSD-3-Clause
Figures as published by the project. See Sources below.
Bill of materials
| Part | Qty | Notes |
|---|---|---|
| T-Motor Antigravity 4004 300 kV | — | Two motors per leg module |
| Broadcom AEDT-9810-Z00 encoder | 1 per motor | |
| PWB 625 CPR codewheel | 1 per motor | |
| Synchroflex AT3 belts (150 mm × 4 mm, 201 mm × 6 mm) | 2 | |
| 61705 2RS stainless bearing | 2 | |
| Machined and printed pulleys and shafts | — |
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 Not published as a ballpark. Start at the project repository.
Tools you'll need
- Lathe or machining service
- FDM/SLA printer
- Belt tension gauge
- Soldering iron
Step-by-step build overview
Electronics & wiring overview
Each micro-driver board runs two motors. Drivers connect to the ODRI master board over SPI, and the master board connects to the PC over Ethernet.
Software
The project ships its own firmware and control code. See the repository for setup.
Driver firmware and the master-board stack are in the sibling ODRI repositories.
Tips from the bench
- ☕ Codewheel runout ruins encoder readings, so check it carefully.
ODRI Open Robot Actuator Hardware (Solo / Bolt) FAQ
Which robots use this actuator?
Solo-8, Solo-12 and Bolt.
Sources
- GitHub repository: open-dynamic-robot-initiative/open_robot_actuator_hardware
- Paper (arXiv 1910.00093)
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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