{
  "specimen": {
    "robot": "ROBOTIS OP3",
    "dex_id": "#010",
    "imported_via": "robot_descriptions 3.3.0 (Python package), module robot_descriptions.op3_mj_description",
    "source": {
      "repo": "https://github.com/deepmind/mujoco_menagerie",
      "commit": "feadf76d42f8a2162426f7d226a3b539556b3bf5",
      "mjcf": "robotis_op3/op3.xml",
      "package": "robotis_op3",
      "license": "Apache-2.0",
      "license_evidence": "LICENSE file in the robotis_op3 directory of the upstream repo: 'Apache License'; Version 2.0, January 2004; the repo root LICENSE carries the same text under the section \"License for contents in the directory 'robotis_op3/'\"",
      "retrieved": "2026-10-29"
    },
    "facts": {
      "robot_name_in_mjcf": "robotis_op3",
      "body_count": 21,
      "bodies_with_inertial": 21,
      "joint_count": 21,
      "joints_by_type": {
        "free": 1,
        "hinge": 20
      },
      "actuator_count": 20,
      "degrees_of_freedom": 20,
      "total_mass_kg": 3.14747,
      "root_body_mass_kg": 1.34928,
      "fact_source": "Parsed from the MJCF at the pinned upstream commit: body/inertial elements under <worldbody>, joint elements (the <default> class stub excluded), the root body's <freejoint/> and the <actuator> list."
    },
    "annotation_note": "This entry arrived by import, not by hand: the description was downloaded by robot_descriptions (module op3_mj_description) from DeepMind's MuJoCo Menagerie, a curated mirror of manufacturers' models; the facts above were parsed out of its robotis_op3 MJCF. Nothing here was gated — importing a description is not a verdict.",
    "honesty": [
      "The Menagerie README calls this a 'simplified' description of the OP3, and it is treated as one: its inertial total is 3.147 kg, below the e-Manual's ~3.5 kg (without the skin cover) for the physical robot. The entry keeps the e-Manual figure; the model's figure is recorded here, with the difference stated, not smoothed over.",
      "The model's 20 hinge joints and 20 position actuators agree with the OP3's 20 Dynamixel servos and the e-Manual's 20-DOF layout.",
      "Gate status stays NOT_GATED: the motion gate grades wheeled ground robots, and no walking gate exists yet.",
      "The parts kit stays undefined (kit: null in catalog/parts-kits.json): the kit generator builds wheeled kits from a spec's wheel block, and this robot has no wheels.",
      "ROBOTIS's own OP3 repositories carry the same Apache-2.0 license (checked against ROBOTIS-GIT/ROBOTIS-OP3's root LICENSE during this import); the license recorded above is the one read from the Menagerie files themselves.",
      "The MJCF tree is not vendored into this repo — the manifest pins the upstream repo, commit and MJCF path."
    ]
  }
}