A method for manufacturing a contoured hole, the hole being manufactured in a wall, the wall comprising a first, a second surface, and a wall thickness between the wall first and second surface. The comprises manufacturing a first non-penetrating hole extending from the first surface and into the wall, wherein a distal end of the first hole is located within the wall such that the first hole does not penetrate the wall second surface, and manufacturing a through hole, wherein the through hole is fluidly connected with first hole and penetrates the wall second surface.

A spindle assembly for machining a cast workpiece includes a fixture that provides rotational movement to the workpiece around a fixture axis. A first spindle provides rotational movement to a cutting tool around a first spindle axis and a second spindle provides rotational movement to a second cutting tool around a second spindle axis. The first spindle axis and the second spindle axis are transverse to the fixture axis. The fixture is disposed between the first spindle and the second spindle. The pivotal movement of the fixture provides access to opposite sides of the workpiece to the first spindle and the second spindle enabling the cutting tools to simultaneously cut opposing sides of the workpiece. The first cutting tool and the second cutting tool are replaceable by a third cutting tool and a fourth cutting tool to cut an alternative or different aperture into the workpiece.

A spindle assembly for machining a cast workpiece includes a fixture that provides rotational movement to the workpiece around a fixture axis. A first spindle provides rotational movement to a cutting tool around a first spindle axis and a second spindle provides rotational movement to a second cutting tool around a second spindle axis. The first spindle axis and the second spindle axis are transverse to the fixture axis. The fixture is disposed between the first spindle and the second spindle. The pivotal movement of the fixture provides access to opposite sides of the workpiece to the first spindle and the second spindle enabling the cutting tools to simultaneously cut opposing sides of the workpiece. The first cutting tool and the second cutting tool are replaceable by a third cutting tool and a fourth cutting tool to cut an alternative or different aperture into the workpiece.