Abstract: The present invention is a pull-out distance arm for measuring both the diameter of a substantially circularly-shaped object and the distance of the plane of the circularly-shaped object from a fixed reference plane. The distance arm incorporates transducers that do not move when the arm is moved and, consequently, there is no movement in the wires connecting to the transducers, resulting in enhanced reliability.

Abstract: An apparatus for determining the imbalance in a rotating object has a drive means for rotating the object about an axis. Transducers measure the force of imbalance of the rotating object, with each transducer producing an electrical signal in response thereto. Electronic means receives the signals from the transducers and calculates the imbalance in the object. Drive means is directly coupled to the rotating object, such as a tire, with the drive means in the hub of the wheel on which the tire is mounted. Cantilever support means having a substantially planar surface provides support for the drive means onto the transducers in the frame of the apparatus.