Abstract: An apparatus and method for balancing a workpiece in which material is removed by advancing a drill, mill or the like into contact with the workpiece and thereafter removing material therefrom. A force transducer is coupled to the workpiece or tool holder to produce an electrical signal in response to the force resulting from contact between the tool and the workpiece to reliably and accurately indicate contact for zero depth reference of the material removing operation.

Abstract: A mass centering method and apparatus for ascertaining and marking the location of the axis of inertia of rough or premachined rotating article, allowing the marked axis to be used as a centerline in further processing in order to keep the remaining unbalance in the finished article as low as possible. The location of the axis of inertia is determined by an ordinary balancing method, and is then positioned relative to a center marking point, such as the centerline of a center drill, by only two revolving movements: one being a rotation of the article about its own axis of rotation, and the other being an eccentric rotation of the article about the axis of a supporting fixture. An appropriate combination of angle settings for both revolving movements allows the system to locate a theoretically unlimited number of marking points within a circular range of a predetermined diameter.