A Novel Measuring Method of Circular Run-Out in any Direction

The difficulty of measuring the run-out of engine valve seat related to the centerline of the valve guide is the determination of the datum axis. A method that the gauge was fixed on the conical surface of the valve seat was chosen. One sensor on the conical surface of the gauge measured the run-out of the valve seat related to the centerline of the gauge. The sensors of the gauge on the guide rod measured the centerline of the valve guide. A novel mathematic model of measurement is established. The advantage of this method is that the method of least square circle is needn't. So it is more conveniently on some occasion.