1. Rule of thirds.
The three-point method can be used to measure the roundness error of the outer circle or the inner circle with a large edge shape error . When measuring, you need to put the workpiece to be measured in the V-shaped block, and then rotate the workpiece in the V-shaped block for one cycle, and then you can read the large indicator value and the small indicator value from the micrometer, which is half of the difference between the two indicator values It is the roundness error of the outer circle of the workpiece to be measured.
2. Rotation axis method.
The roundness meter is a measuring tool for measuring the roundness tolerance of the piston rod by the rotating shaft method. The system has two forms: sensor rotation and table rotation. During the test, the circle track formed by one revolution of the shaft in the precision shaft system can be compared with the measured circle. The difference in the radius of the circle is converted into an electric signal by the electric length measuring sensor. After the circuit board is processed and the computer calculates, the roundness error can be displayed on the monitor, or the contour of the measured circle can be recorded by the recorder.
3. Two-point method.
The precision piston rod two-point measurement method is mainly suitable for measuring the roundness tolerance of the outer circle or the inner circle with uniform edge shape error. When measuring, you can use a micrometer and a comparator to measure, and then take half of the diameter difference on a certain section of the measured circle as the roundness error of the section.
4. Coordinate method.
In general, the coordinate measurement method needs to be measured on a coordinate measuring machine. In the measurement process, firstly, the coordinate values ??x and y of several points on the measured circle are measured according to the rectangular coordinate system selected in advance, and then the roundness tolerance is calculated by the electronic computer according to the selected roundness error evaluation method.
https://www.xhychromerod.com/