{
 "id": "59-enclosure-base",
 "name": "Enclosure base with bosses and ribs",
 "description": "100x60x30 box, vertical edges R6, shelled 2 (top open); 4 d8 screw bosses to z=26 with d3 holes 20 deep; a 2 mm rib along Y 10 tall.",
 "exercises": [
  "fillet",
  "shell",
  "extrude_join",
  "extrude_cut",
  "realistic"
 ],
 "units": {
  "length": "mm",
  "angle": "deg",
  "area": "mm2",
  "volume": "mm3"
 },
 "conventions": {
  "world": "right-handed; Z up. XY/XZ/YZ are the origin planes.",
  "sketch_frame": "sketch-local 2D coords; world = plane.origin + x*plane.x_dir + y*plane.y_dir (origin in mm). Profile 'loops' list sketch entity ids.",
  "point_refs": "'<id>.start' / '<id>.end' / '<id>.center' reuse (share) that existing sketch point; 'at' is its position when referenced.",
  "extrude_direction": "positive = along sketch plane normal unless stated",
  "selections": "selected faces/edges carry 'point': a world-space point on the face / the edge's parametric midpoint; pick the nearest face/edge to it."
 },
 "parameters": [],
 "features": [
  {
   "op": "sketch",
   "name": "Box_sketch",
   "plane": {
    "ref": "XY",
    "origin": [
     0.0,
     0.0,
     0.0
    ],
    "x_dir": [
     1.0,
     0.0,
     0.0
    ],
    "y_dir": [
     0.0,
     1.0,
     0.0
    ],
    "normal": [
     0.0,
     0.0,
     1.0
    ]
   },
   "entities": [
    {
     "type": "line",
     "start": {
      "at": [
       0,
       0
      ]
     },
     "end": {
      "at": [
       100,
       0
      ]
     },
     "id": "l1"
    },
    {
     "type": "line",
     "start": {
      "ref": "l1.end",
      "at": [
       100.0,
       0.0
      ]
     },
     "end": {
      "at": [
       100,
       60
      ]
     },
     "id": "l2"
    },
    {
     "type": "line",
     "start": {
      "ref": "l2.end",
      "at": [
       100.0,
       60.0
      ]
     },
     "end": {
      "at": [
       0,
       60
      ]
     },
     "id": "l3"
    },
    {
     "type": "line",
     "start": {
      "ref": "l3.end",
      "at": [
       0.0,
       60.0
      ]
     },
     "end": {
      "ref": "l1.start",
      "at": [
       0.0,
       0.0
      ]
     },
     "id": "l4"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "extrude",
   "name": "Box",
   "operation": "new",
   "profiles": [
    {
     "sketch": "Box_sketch",
     "loops": [
      {
       "outer": true,
       "curves": [
        "l1",
        "l2",
        "l3",
        "l4"
       ]
      }
     ]
    }
   ],
   "extent": {
    "type": "distance",
    "distance": 30,
    "direction": "positive"
   },
   "result_bodies": [
    "Enclosure"
   ]
  },
  {
   "op": "fillet",
   "name": "CornerFillet",
   "type": "constant_radius",
   "radius": 6,
   "tangent_chain": false,
   "edge_selection": "the 4 outer vertical edges",
   "edges": [
    {
     "type": "line",
     "start": [
      0.0,
      60.0,
      0.0
     ],
     "end": [
      0.0,
      60.0,
      30.0
     ],
     "point": [
      0.0,
      60.0,
      15.0
     ]
    },
    {
     "type": "line",
     "start": [
      100.0,
      60.0,
      0.0
     ],
     "end": [
      100.0,
      60.0,
      30.0
     ],
     "point": [
      100.0,
      60.0,
      15.0
     ]
    },
    {
     "type": "line",
     "start": [
      100.0,
      0.0,
      0.0
     ],
     "end": [
      100.0,
      0.0,
      30.0
     ],
     "point": [
      100.0,
      0.0,
      15.0
     ]
    },
    {
     "type": "line",
     "start": [
      0.0,
      0.0,
      0.0
     ],
     "end": [
      0.0,
      0.0,
      30.0
     ],
     "point": [
      0.0,
      0.0,
      15.0
     ]
    }
   ]
  },
  {
   "op": "shell",
   "name": "Shell1",
   "faces_removed": [
    {
     "type": "plane",
     "normal_at_point_on_face": [
      0.0,
      0.0,
      1.0
     ],
     "plane_normal_outward": [
      0.0,
      0.0,
      1.0
     ],
     "point": [
      50.0,
      30.0,
      30.0
     ]
    }
   ],
   "face_selection": "top face (z=30)",
   "inside_thickness": 2,
   "outside_thickness": 0,
   "tangent_chain": false
  },
  {
   "op": "construction_plane",
   "name": "Floor2",
   "method": "offset",
   "base": "XY",
   "offset": 2
  },
  {
   "op": "sketch",
   "name": "Bosses",
   "plane": {
    "ref": "construction plane Floor2 (inner floor, z=2)",
    "origin": [
     0.0,
     0.0,
     2.0
    ],
    "x_dir": [
     1.0,
     0.0,
     0.0
    ],
    "y_dir": [
     0.0,
     1.0,
     0.0
    ],
    "normal": [
     0.0,
     0.0,
     1.0
    ]
   },
   "entities": [
    {
     "type": "circle",
     "center": {
      "at": [
       8,
       8
      ]
     },
     "radius": 4,
     "id": "c1"
    },
    {
     "type": "circle",
     "center": {
      "at": [
       92,
       8
      ]
     },
     "radius": 4,
     "id": "c2"
    },
    {
     "type": "circle",
     "center": {
      "at": [
       8,
       52
      ]
     },
     "radius": 4,
     "id": "c3"
    },
    {
     "type": "circle",
     "center": {
      "at": [
       92,
       52
      ]
     },
     "radius": 4,
     "id": "c4"
    },
    {
     "type": "line",
     "start": {
      "at": [
       49,
       2
      ]
     },
     "end": {
      "at": [
       51,
       2
      ]
     },
     "id": "r1"
    },
    {
     "type": "line",
     "start": {
      "ref": "r1.end",
      "at": [
       51.0,
       2.0
      ]
     },
     "end": {
      "at": [
       51,
       58
      ]
     },
     "id": "r2"
    },
    {
     "type": "line",
     "start": {
      "ref": "r2.end",
      "at": [
       51.0,
       58.0
      ]
     },
     "end": {
      "at": [
       49,
       58
      ]
     },
     "id": "r3"
    },
    {
     "type": "line",
     "start": {
      "ref": "r3.end",
      "at": [
       49.0,
       58.0
      ]
     },
     "end": {
      "ref": "r1.start",
      "at": [
       49.0,
       2.0
      ]
     },
     "id": "r4"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "extrude",
   "name": "Bosses",
   "operation": "join",
   "profiles": [
    {
     "sketch": "Bosses",
     "loops": [
      {
       "outer": true,
       "curves": [
        "c1"
       ]
      }
     ]
    },
    {
     "sketch": "Bosses",
     "loops": [
      {
       "outer": true,
       "curves": [
        "c2"
       ]
      }
     ]
    },
    {
     "sketch": "Bosses",
     "loops": [
      {
       "outer": true,
       "curves": [
        "c3"
       ]
      }
     ]
    },
    {
     "sketch": "Bosses",
     "loops": [
      {
       "outer": true,
       "curves": [
        "c4"
       ]
      }
     ]
    }
   ],
   "extent": {
    "type": "distance",
    "distance": 24,
    "direction": "positive"
   },
   "result_bodies": [
    "Enclosure"
   ]
  },
  {
   "op": "extrude",
   "name": "Rib",
   "operation": "join",
   "profiles": [
    {
     "sketch": "Bosses",
     "loops": [
      {
       "outer": true,
       "curves": [
        "r1",
        "r2",
        "r3",
        "r4"
       ]
      }
     ]
    }
   ],
   "extent": {
    "type": "distance",
    "distance": 10,
    "direction": "positive"
   },
   "result_bodies": [
    "Enclosure"
   ]
  },
  {
   "op": "construction_plane",
   "name": "BossTop",
   "method": "offset",
   "base": "XY",
   "offset": 26
  },
  {
   "op": "sketch",
   "name": "ScrewHoles",
   "plane": {
    "ref": "construction plane BossTop (z=26)",
    "origin": [
     0.0,
     0.0,
     26.0
    ],
    "x_dir": [
     1.0,
     0.0,
     0.0
    ],
    "y_dir": [
     0.0,
     1.0,
     0.0
    ],
    "normal": [
     0.0,
     0.0,
     1.0
    ]
   },
   "entities": [
    {
     "type": "circle",
     "center": {
      "at": [
       8,
       8
      ]
     },
     "radius": 1.5,
     "id": "c1"
    },
    {
     "type": "circle",
     "center": {
      "at": [
       92,
       8
      ]
     },
     "radius": 1.5,
     "id": "c2"
    },
    {
     "type": "circle",
     "center": {
      "at": [
       8,
       52
      ]
     },
     "radius": 1.5,
     "id": "c3"
    },
    {
     "type": "circle",
     "center": {
      "at": [
       92,
       52
      ]
     },
     "radius": 1.5,
     "id": "c4"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "extrude",
   "name": "ScrewHoles",
   "operation": "cut",
   "profiles": [
    {
     "sketch": "ScrewHoles",
     "loops": [
      {
       "outer": true,
       "curves": [
        "c1"
       ]
      }
     ]
    },
    {
     "sketch": "ScrewHoles",
     "loops": [
      {
       "outer": true,
       "curves": [
        "c3"
       ]
      }
     ]
    },
    {
     "sketch": "ScrewHoles",
     "loops": [
      {
       "outer": true,
       "curves": [
        "c2"
       ]
      }
     ]
    },
    {
     "sketch": "ScrewHoles",
     "loops": [
      {
       "outer": true,
       "curves": [
        "c4"
       ]
      }
     ]
    }
   ],
   "extent": {
    "type": "distance",
    "distance": 20,
    "direction": "negative"
   },
   "result_bodies": [
    "Enclosure"
   ]
  }
 ]
}