{
 "id": "60-pipe-flange",
 "name": "Weld-neck pipe flange",
 "description": "Revolved flange (bore d50, flange OD150 x16, tapered neck to z=50); 8 x d14 bolt holes on PCD120; bore top edge chamfer 2; neck root fillet R4.",
 "exercises": [
  "revolve",
  "extrude_cut",
  "circular_pattern",
  "chamfer",
  "fillet",
  "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": "Profile",
   "plane": {
    "ref": "XZ",
    "origin": [
     0.0,
     0.0,
     0.0
    ],
    "x_dir": [
     1.0,
     0.0,
     0.0
    ],
    "y_dir": [
     0.0,
     0.0,
     -1.0
    ],
    "normal": [
     0.0,
     1.0,
     0.0
    ]
   },
   "entities": [
    {
     "type": "line",
     "start": {
      "at": [
       25.0,
       0.0
      ]
     },
     "end": {
      "at": [
       75.0,
       0.0
      ]
     },
     "id": "l1"
    },
    {
     "type": "line",
     "start": {
      "ref": "l1.end",
      "at": [
       75.0,
       0.0
      ]
     },
     "end": {
      "at": [
       75.0,
       -16.0
      ]
     },
     "id": "l2"
    },
    {
     "type": "line",
     "start": {
      "ref": "l2.end",
      "at": [
       75.0,
       -16.0
      ]
     },
     "end": {
      "at": [
       40.0,
       -16.0
      ]
     },
     "id": "l3"
    },
    {
     "type": "line",
     "start": {
      "ref": "l3.end",
      "at": [
       40.0,
       -16.0
      ]
     },
     "end": {
      "at": [
       37.0,
       -50.0
      ]
     },
     "id": "l4"
    },
    {
     "type": "line",
     "start": {
      "ref": "l4.end",
      "at": [
       37.0,
       -50.0
      ]
     },
     "end": {
      "at": [
       25.0,
       -50.0
      ]
     },
     "id": "l5"
    },
    {
     "type": "line",
     "start": {
      "ref": "l5.end",
      "at": [
       25.0,
       -50.0
      ]
     },
     "end": {
      "ref": "l1.start",
      "at": [
       25.0,
       0.0
      ]
     },
     "id": "l6"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "revolve",
   "name": "Revolve1",
   "operation": "new",
   "profile": {
    "sketch": "Profile",
    "loops": [
     {
      "outer": true,
      "curves": [
       "l1",
       "l2",
       "l3",
       "l4",
       "l5",
       "l6"
      ]
     }
    ]
   },
   "axis": {
    "ref": "world Z axis",
    "origin": [
     0,
     0,
     0
    ],
    "dir": [
     0,
     0,
     1
    ]
   },
   "angle": 360,
   "result_bodies": [
    "Flange"
   ]
  },
  {
   "op": "sketch",
   "name": "BoltHole",
   "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": "circle",
     "center": {
      "at": [
       60,
       0
      ]
     },
     "radius": 7,
     "id": "c1"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "extrude",
   "name": "BoltHole",
   "operation": "cut",
   "profiles": [
    {
     "sketch": "BoltHole",
     "loops": [
      {
       "outer": true,
       "curves": [
        "c1"
       ]
      }
     ]
    }
   ],
   "extent": {
    "type": "through_all",
    "direction": "positive"
   },
   "result_bodies": [
    "Flange"
   ]
  },
  {
   "op": "circular_pattern",
   "name": "BoltPattern",
   "pattern_of": "features",
   "features": [
    "BoltHole (1)"
   ],
   "axis": {
    "ref": "world Z axis",
    "origin": [
     0,
     0,
     0
    ],
    "dir": [
     0,
     0,
     1
    ]
   },
   "count": 8,
   "total_angle": 360,
   "symmetric": false
  },
  {
   "op": "chamfer",
   "name": "BoreChamfer",
   "type": "equal_distance",
   "distance": 2,
   "tangent_chain": false,
   "edge_selection": "bore circle r=25 at z=50 (top of neck)",
   "edges": [
    {
     "type": "circle",
     "start": [
      25.0,
      0.0,
      50.0
     ],
     "end": [
      25.0,
      0.0,
      50.0
     ],
     "center": [
      0.0,
      0.0,
      50.0
     ],
     "axis": [
      0.0,
      0.0,
      1.0
     ],
     "point": [
      -25.0,
      0.0,
      50.0
     ]
    }
   ]
  },
  {
   "op": "fillet",
   "name": "NeckFillet",
   "type": "constant_radius",
   "radius": 4,
   "tangent_chain": false,
   "edge_selection": "circle r=40 at z=16 (neck meets flange face, concave)",
   "edges": [
    {
     "type": "circle",
     "start": [
      40.0,
      0.0,
      16.0
     ],
     "end": [
      40.0,
      0.0,
      16.0
     ],
     "center": [
      0.0,
      0.0,
      16.0
     ],
     "axis": [
      0.0,
      0.0,
      1.0
     ],
     "point": [
      -40.0,
      0.0,
      16.0
     ]
    }
   ]
  }
 ]
}