{
  "patch_version": "1.0",
  "target_model": "lcd25_harmonic_reducer",
  "intent": "Add a coaxial keyed output shaft without authoring a placement transform.",
  "operations": [
    {
      "op": "add_parameter",
      "id": "output_shaft_diameter",
      "value": {
        "kind": "length",
        "value": 14.0,
        "unit": "mm",
        "editable": true,
        "bounds": [10.0, 20.0],
        "status": "specified",
        "description": "Output shaft journal diameter."
      }
    },
    {
      "op": "add_parameter",
      "id": "output_shaft_length",
      "value": {
        "kind": "length",
        "value": 45.0,
        "unit": "mm",
        "editable": true,
        "bounds": [25.0, 80.0],
        "status": "specified",
        "description": "Usable shaft extension measured from the output mounting face."
      }
    },
    {
      "op": "add_component",
      "value": {
        "id": "output_shaft",
        "role": "external_torque_shaft",
        "archetype": "stepped_keyed_shaft",
        "lifecycle": "optional",
        "generation": {
          "strategy": "semantic_feature_program",
          "family": "stepped_output_shaft",
          "parameter_bindings": {
            "journal_diameter": "output_shaft_diameter",
            "extension_length": "output_shaft_length",
            "mating_bore": "output_bore_diameter"
          }
        },
        "interfaces": [
          {
            "id": "shaft_axis",
            "type": "axis",
            "construction": "primary_axis"
          },
          {
            "id": "mounting_shoulder",
            "type": "plane",
            "construction": "rear_axial_face"
          },
          {
            "id": "flange_fit",
            "type": "shaft_seat",
            "construction": "outer_cylindrical_surface",
            "parameter_refs": ["output_shaft_diameter"]
          },
          {
            "id": "torque_drive",
            "type": "torque_interface",
            "construction": "generated_feature",
            "qualifiers": ["key_or_spline_selected_by_load"]
          },
          {
            "id": "external_shaft_end",
            "type": "plane",
            "construction": "front_axial_face"
          }
        ],
        "material_class": "alloy_steel",
        "tags": ["rotating", "output", "public_interface"]
      }
    },
    {
      "op": "add_relation",
      "value": {
        "id": "output_shaft_centering",
        "type": "coaxial",
        "a": "output_flange.rotation_axis",
        "b": "output_shaft.shaft_axis",
        "intent": "Center the new shaft on the solved output axis.",
        "mobility": "fixed"
      }
    },
    {
      "op": "add_relation",
      "value": {
        "id": "output_shaft_seating",
        "type": "face_mate",
        "a": "output_flange.external_mount_face",
        "b": "output_shaft.mounting_shoulder",
        "intent": "Locate the shaft shoulder from the output flange mounting face.",
        "value": 0.0,
        "tolerance": 0.01,
        "mobility": "fixed"
      }
    },
    {
      "op": "add_relation",
      "value": {
        "id": "output_shaft_fit",
        "type": "insert",
        "a": "output_flange.output_bore",
        "b": "output_shaft.flange_fit",
        "intent": "Fit the shaft journal into the output flange bore.",
        "tolerance": 0.01,
        "mobility": "fixed"
      }
    },
    {
      "op": "add_relation",
      "value": {
        "id": "output_shaft_torque_lock",
        "type": "torque_lock",
        "a": "output_flange.output_bore",
        "b": "output_shaft.torque_drive",
        "intent": "Transfer output torque through a keyed or splined interface.",
        "mobility": "fixed"
      }
    },
    {
      "op": "add_rigid_group_member",
      "group": "output_group",
      "component": "output_shaft"
    },
    {
      "op": "add_preserved_interface",
      "value": "output_shaft.external_shaft_end"
    }
  ]
}