Method and apparatus for machining crankshafts

A crankshaft is machined by first securing it in first and second radially displaceable grippers of first and second holders rotatable about a common grinding axis and orienting the workpiece axis coaxial with the grinding axis. Then the crankshaft is released from the first gripper, and the second holder is rotated to align the first crankpin radially with the grinding axis. Subsequently the crankshaft is regripped by the first gripper and released by the second gripper and the second holder is rotated relative to the crankshaft until the second holder is aligned with its displacement direction lying in a common plane with the grinding axis and the displacement direction of the first gripper. Finally, both the grippers are shifted parallel to each other in their displacement directions to center the first crankpin on the grinding axis, and the crankshaft is about the grinding axis while machining the first crankpin.