Bolt

Based on published sources · Not tested by us · Sources checked 2026-09-30

Overview

A six-actuator research biped with passive ankles, tethered power/data and no active yaw control. [S001]

Bolt's documented body has two legs with three active degrees of freedom each and a passive ankle joint. There is no active leg-rotation axis, so the design documentation says yaw cannot be controlled directly. Its line-contact feet help stabilize that orientation. This is a specific constraint when choosing a locomotion experiment, rather than a general-purpose humanoid configuration. [S005]

Official website · Source code

Specifications

Detail	Description
Type	Biped with three active axes per leg and a passive ankle Reported by source [S005] [S006] [S007] [S008] [S009] [S011] [S013] · Checked 2026-09-30
Intended users	Legged robotics laboratories; Builders with precision assembly and embedded-control experience Editorial assessment [S001] · Checked 2026-09-30
Assembly	Prepare precision actuator cores and printed shells, assemble selected leg/body modules, wire custom electronics, then calibrate. Reported by source [S005] [S006] [S007] [S008] [S009] [S011] [S013] · Checked 2026-09-30
Calibration	Measure per-joint index-to-zero offsets with printed fixtures; roughly align legs at startup; repeat offset measurement after actuator repair or replacement. Reported by source [S005] [S006] [S007] [S008] [S009] [S011] [S013] · Checked 2026-09-30
Operating system	Not known
Computer needed	External real-time control computer; master-board SDK requires a direct Ethernet interface or compatible raw-wireless interface Reported by source [S005] [S006] [S007] [S008] [S009] [S011] [S013] · Checked 2026-09-30

Assembly and use

The small body is only part of the experimental setup

The hardware guide describes an interface wire carrying power and Ethernet, a Master Board, three Micro Driver boards and an IMU. It also offers body-top variants with Vicon marker mounts; those markers are optional and only relevant to a motion-capture setup. The pictured standing robot is explicitly described as held by a string. Neither that photograph nor the preserved CAD establishes unsupported standing in our own tests. [S005]

Each leg is a custom assembly using the shared brushless actuator cores. The core combines an optical encoder and two belt-reduction stages. A supplier encoder-kit route can replace machining and shaft preparation, but the documented build still needs fitting, threaded inserts, wiring and actuator assembly. Current sourcing and an exact delivered budget have not been checked. [S005] [S007] [S008]

Include calibration and programming equipment

The shared calibration guide includes a biped-specific printed fixture. At startup the joint angles are unknown; the procedure uses rough manual alignment, encoder-index search and previously measured offsets. Repairing or replacing an actuator requires measuring the affected offset again. That is recurring maintenance work to measure during a build trial. [S006]

The separately preserved Master Board release includes firmware and an SDK, but it is not a complete matched biped controller. Its documented host connection uses a dedicated Ethernet interface or specially supported raw wireless communication, and the reviewed flashing instructions specify ESP-IDF 3.x compatibility, using an installer from 4.0.1 before rolling back to commit 8d1a9c0. They also require a USB-to-serial programming arrangement with accessible RTS/DTR signals and reset circuitry. The Micro Drivers use a separate XDS100V2 JTAG emulator and adapter cable. The robot, host, motor-driver firmware and chosen control program must therefore be versioned together before a reproduction claim. [S009] [S011] [S012] [S013]

The mechanical and Micro Driver documentation carries BSD-3-Clause terms, while the Master Board has BSD-2-Clause terms. Purchased parts and other control dependencies still need separate checks. No assembly, balance control, calibration or support workload was tested here. [S003] [S011]

Cost

No current, complete configuration-specific build cost has been established for this profile.

Source files and licenses

Available project sources support research coverage; complete build and commercial qualification remain separate.

Layer	Availability / license
mechanical design	available · BSD-3-Clause Hardware repository scope; separately hosted boards and purchased components retain their own terms. [S003] [S005] [S009]
electronics	available · BSD-3-Clause Hardware repository scope; separately hosted boards and purchased components retain their own terms. [S003] [S005] [S009]
firmware	available · BSD-2-Clause Master Board repository only; not a complete robot control/dependency pack. [S011] [S012] [S013]
software	available · BSD-2-Clause Master Board repository only; not a complete robot control/dependency pack. [S011] [S012] [S013]
documentation	available · BSD-3-Clause Hardware repository scope; separately hosted boards and purchased components retain their own terms. [S003] [S005] [S009]

No particular learned controller or dataset selected in this hardware review.

References

Links identify the documentation and revisions used in this profile. Access dates record when each source was retrieved.

S001 · open-dynamic-robot-initiative / project contributors
Upstream project overview
Accessed 2026-09-30 · README.md
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S002 · open-dynamic-robot-initiative / project contributors
Repository revision and release metadata
Accessed 2026-09-30 · 66af1522b4fba0ec4a1d7790e66f5e4652208d30
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S003 · open-dynamic-robot-initiative / project contributors
Repository license
Accessed 2026-09-30 · LICENSE
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S004 · open-dynamic-robot-initiative / project contributors
Pinned repository artifact inventory
Accessed 2026-09-30 · 66af1522b4fba0ec4a1d7790e66f5e4652208d30 archive file inventory
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S009 · open-dynamic-robot-initiative / project contributors
electronics/micro_driver_electronics/README.md
Accessed 2026-09-30 · electronics/micro_driver_electronics/README.md
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S007 · open-dynamic-robot-initiative / project contributors
mechanics/actuator_module_v1/actuator_module_v1.1.md
Accessed 2026-09-30 · mechanics/actuator_module_v1/actuator_module_v1.1.md
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S008 · open-dynamic-robot-initiative / project contributors
mechanics/actuator_module_v1/details/details_tools.md
Accessed 2026-09-30 · mechanics/actuator_module_v1/details/details_tools.md
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S005 · open-dynamic-robot-initiative / project contributors
mechanics/biped_6dof_v1/README.md
Accessed 2026-09-30 · mechanics/biped_6dof_v1/README.md
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S006 · open-dynamic-robot-initiative / project contributors
mechanics/general/robot_calibration.md
Accessed 2026-09-30 · mechanics/general/robot_calibration.md
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S011 · open-dynamic-robot-initiative / project contributors
Master Board release and license
Accessed 2026-09-30 · README and LICENSE at ab2c7173e9d57a99ef8bf2fca430fa376c6cc4b4
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S012 · open-dynamic-robot-initiative / project contributors
firmware/README.md
Accessed 2026-09-30 · firmware/README.md
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.
S013 · open-dynamic-robot-initiative / project contributors
sdk/master_board_sdk/README.md
Accessed 2026-09-30 · sdk/master_board_sdk/README.md
Source notes
Source text inspected for the cited scoped claims; see profile claim notes.

Research and review details

Source research only; no installation, physical build or performance test performed. No affiliate links added.

Profile edited 2026-09-30 · Sources checked 2026-09-30 · Next review target 2026-10-30

Combined hardware and software repository revision: 66af1522b4fb · Activity recorded 2022-09-06 [S002]

Correction guidance · Discussion is not enabled · Profile format 0.5.0-draft.1

Change history

September 29, 2026 — First research profile published.