How to detect the accuracy of CNC lathes

The CNC lathe refers to the position accuracy achieved by each coordinate axis under the control of the CNC device. In the detection of the accuracy of the CNC lathe, the inverse error of the linear motion can be used for detection. The technicians of our company summarized this process:

The reverse error of the linear motion of the CNC lathe is also called the loss of momentum. It includes the reverse dead zone of the drive part “such as servo motor, servo hydraulic motor and stepping motor” on the coordinate axis feed transmission chain, and the equipment A comprehensive reflection of errors such as backlash and elastic deformation of the motion transmission pair. The greater the error, the lower the equipment positioning accuracy and repeat positioning accuracy. The detection method of reverse error is to move a distance in the forward or reverse direction in advance within the stroke of the measured coordinate axis and use the stop position as the reference, and then give a certain movement command value in the same direction to make it move a certain distance , And then the device moves the same distance in the opposite direction to measure the difference between the stop position and the reference position. Perform multiple measurements at the three positions near the midpoint and both ends of the equipment stroke “generally 7 times”, find the average value at each position, and take the maximum value of the average value as the reverse error value. Linear motion positioning accuracy is generally carried out under no-load conditions on the CNC lathe and worktable.

According to the national standard and the ISO standard stipulated by the International Organization for Standardization, the inspection of CNC lathes should be subject to laser measurement. In the absence of a laser interferometer, it is also possible for general users to use a standard scale with an optical reading microscope for comparative measurement. However, the accuracy of the measuring instrument must be 1-2 levels higher than the measured accuracy. In order to reflect all the errors in the multiple positioning of the equipment, the ISC standard stipulates that each positioning point is calculated based on the five measurement data to calculate the average value and dispersion, and the dispersion belt constitutes the positioning point dispersion band.