{
 "id": "11-circular-pattern-flange",
 "name": "Flange with circular hole pattern",
 "description": "Annulus OD100 / ID30 extruded 10; d=10 hole at (40,0) cut through; circular pattern x6 over 360 about Z.",
 "exercises": [
  "extrude",
  "annulus_profile",
  "extrude_cut",
  "circular_pattern"
 ],
 "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": "FlangeSketch",
   "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": [
       0,
       0
      ]
     },
     "radius": 50,
     "id": "c_out"
    },
    {
     "type": "circle",
     "center": {
      "ref": "c_out.center",
      "at": [
       0.0,
       0.0
      ]
     },
     "radius": 15,
     "id": "c_in"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "extrude",
   "name": "Flange",
   "operation": "new",
   "profiles": [
    {
     "sketch": "FlangeSketch",
     "loops": [
      {
       "outer": true,
       "curves": [
        "c_out"
       ]
      },
      {
       "outer": false,
       "curves": [
        "c_in"
       ]
      }
     ]
    }
   ],
   "extent": {
    "type": "distance",
    "distance": 10,
    "direction": "positive"
   },
   "result_bodies": [
    "Flange"
   ]
  },
  {
   "op": "sketch",
   "name": "HoleSketch",
   "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": [
       40,
       0
      ]
     },
     "radius": 5,
     "id": "c1"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "extrude",
   "name": "Hole1",
   "operation": "cut",
   "profiles": [
    {
     "sketch": "HoleSketch",
     "loops": [
      {
       "outer": true,
       "curves": [
        "c1"
       ]
      }
     ]
    }
   ],
   "extent": {
    "type": "through_all",
    "direction": "positive"
   },
   "result_bodies": [
    "Flange"
   ]
  },
  {
   "op": "circular_pattern",
   "name": "CircPattern1",
   "pattern_of": "features",
   "features": [
    "Hole1"
   ],
   "axis": {
    "ref": "world Z axis",
    "origin": [
     0,
     0,
     0
    ],
    "dir": [
     0,
     0,
     1
    ]
   },
   "count": 6,
   "total_angle": 360,
   "symmetric": false
  }
 ]
}