Needs custom circuit boards, machined parts and a tethered PC, and has not been updated since 2022.
Bolt is a small research biped from the Open Dynamic Robot Initiative (Max Planck Institute and NYU) with three torque-controlled brushless joints per leg and passive ankles. It shares the 3D-printed actuator modules and custom driver electronics of the Solo quadruped, weighs about 1.3 kg, and is used for studying dynamic walking control.
At a glance
| Parts cost | $4,700 (2022) builder · Material cost reported by one builder in the US in 2022. The project gives no figure source ↗ |
|---|---|
| Difficulty | 5/5 Expert · Custom PCBs, machined and modified parts, an expensive industrial IMU and a tethered real-time control stack. |
| Build time | Not stated |
| Tools needed | 3D printer (body and actuator shells), soldering and fine electronics work, a lathe or ordered parts for encoder code-wheel modification, machined shafts per the actuator docs |
| Motors | 6 brushless actuator modules (T-Motor Antigravity 4004 motors; belt reduction unconfirmed) |
| Controller | ODRI Master Board plus Micro Driver boards, tethered over Ethernet to an external real-time PC |
| Sensors | Lord Microstrain 3DM-CX5-25 IMU, optical encoders, optional foot contact switches |
| Published | ✓ Parts list✓ CAD/STL✓ Assembly guide✓ Wiring✓ Software✗ Video GitHub Markdown docs with photos, STEP/FreeCAD/SolidWorks CAD, separate driver repos; discussion on odri.discourse.group |
| Activity | Last update 2022-09-06 · 1,481 GitHub stars · ODRI Discourse forum, 258 forks of the shared hardware repo (most activity is on the Solo quadruped) |
| Kits | PAL Robotics offered Solo kits (no Bolt kit confirmed) |
Licenses
| Design files | BSD-3-Clause source ↗ |
|---|---|
| Code | BSD-3-Clause source ↗ |
| Documentation | BSD-3-Clause (docs are Markdown in the same repo) source ↗ |
Builder notes
Practical points from the project's issue tracker, forum and docs, each linked to its source.
- The maintainers say ODRI robots are research platforms that are not optimized for cost, and that the IMU is the single most expensive part. One builder put the Bolt materials at about $4,700 in the US in 2022. source ↗
- The encoder code wheel has an aluminum collar that the team removes on a lathe with a parting-off tool, so a lathe or a machine-shop order is effectively required. source ↗
- Bolt has no hip-yaw joint, so it cannot control its heading directly and relies on line-contact feet to resist yaw. It is also powered and controlled through a tether cable. source ↗
- A builder reported that the foot-contact sensor schematic used resistor values that kept it from ever triggering, so the current schematic should be checked against that issue before ordering boards. source ↗
Other bipeds plans
- Otto DIY · $60–$70 · difficulty 1/5
- Open Duck Mini v2 · $400 · difficulty 3/5