{
 "id": "56-holes-on-curved-face",
 "name": "Holes on a cylindrical face",
 "description": "Cylinder r25 h40 (axis Z); two d6 radial blind holes 10 deep placed on the curved face at (25,0,20) and (0,25,20).",
 "exercises": [
  "hole_on_curved_face",
  "hole_blind"
 ],
 "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": "S1",
   "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": 25,
     "id": "c1"
    }
   ],
   "constraints": [],
   "dimensions": []
  },
  {
   "op": "extrude",
   "name": "Cyl",
   "operation": "new",
   "profiles": [
    {
     "sketch": "S1",
     "loops": [
      {
       "outer": true,
       "curves": [
        "c1"
       ]
      }
     ]
    }
   ],
   "extent": {
    "type": "distance",
    "distance": 40,
    "direction": "positive"
   },
   "result_bodies": [
    "Cyl"
   ]
  },
  {
   "op": "hole",
   "name": "Hole1",
   "hole_type": "simple",
   "face": {
    "type": "cylinder",
    "normal_at_point_on_face": [
     0.0,
     1.0,
     0.0
    ],
    "axis_origin": [
     0.0,
     0.0,
     0.0
    ],
    "axis": [
     0.0,
     0.0,
     1.0
    ],
    "point": [
     0.0,
     25.0,
     20.0
    ]
   },
   "position": [
    25,
    0,
    20
   ],
   "direction": "along the inward surface normal (radial, toward the axis)",
   "diameter": 6,
   "depth": 10,
   "tip_angle": 118,
   "extent": "distance"
  },
  {
   "op": "hole",
   "name": "Hole2",
   "hole_type": "simple",
   "face": {
    "type": "cylinder",
    "normal_at_point_on_face": [
     0.992773892,
     0.12,
     0.0
    ],
    "axis_origin": [
     0.0,
     0.0,
     0.0
    ],
    "axis": [
     0.0,
     0.0,
     1.0
    ],
    "point": [
     24.819347292,
     3.0,
     20.0
    ]
   },
   "position": [
    0,
    25,
    20
   ],
   "direction": "along the inward surface normal (radial, toward the axis)",
   "diameter": 6,
   "depth": 10,
   "tip_angle": 118,
   "extent": "distance"
  }
 ]
}