The use of CNC machine tools has become increasingly widespread in the machinery industry. Ensuring the accuracy of these machines is a crucial step during both acceptance and operation. The precision of CNC machine tools—specifically, repeatability, positioning accuracy, and axis reversal—is central to their overall performance. On January 1, 1990, the State Bureau of Technical Supervision officially issued the standard for evaluating the position of numerically controlled machine tools: GB10931-89, titled "Evaluation Method of Positional Accuracy of Digitally Controlled Machine Tools." This document clearly defines terminology, formulas, and measurement methods. However, it does not specify strict limits on the instruments used for measuring positional accuracy. Currently, several instruments are used to assess positional accuracy, such as laser interferometers, precision line scales with reading microscopes, reference step gauges, and lever dial gauges (or electronic micrometers). Among these, the method using a dial gauge ranks second only to the laser interferometer. However, this approach can be costly, and its step size may not fully align with the requirements outlined in GB10931-89. Therefore, the cost and performance do not always match well. When companies receive imported CNC equipment, they often create a gauge similar to the step gauge based on its characteristics. This is called a standard step gauge, and its structure is shown in the figure. The pitch of the quasi-step gauge is adjusted according to actual needs but must meet the standards set by GB10931-89. The holes at both ends are not only for manufacturing purposes but also for fixing the CNC lathe between the headstock and tailstock. Plane N is designed for easy placement on the CNC machine tool table. During the manufacturing process, multiple aging treatments should be performed, and cold treatment is recommended to minimize residual stress and improve dimensional stability. After completion, the distance between adjacent sides (measured to 0.001mm) is recorded using high-resolution instruments like a tool microscope, and the values are engraved on the corresponding positions of the gauge. If possible, using a coordinate measuring machine to measure the distances between adjacent faces would be even more accurate. To test the CNC lathe using a quasi-step gauge, the fixture is placed between the headstock and tailstock, and the lever dial gauge is mounted on the tool holder, positioned close to the gauge. The distance between the end faces is input into the numerical control system, and the program is ready for testing. When testing coordinate position accuracy, the quasi-step gauge is placed on the tool post with its plane parallel to the feed direction. The lever dial gauge can be mounted on the bed, and the test can begin. For X and Y-axis measurements, the quasi-step gauge is placed on the workbench, and the lever dial gauge is mounted on the spindle. When measuring coordinates, the quasi-step gauge’s plane is fixed to the workbench using a square ruler. The lever dial indicator is then placed on the spindle, and the rest of the steps follow the same procedure as for the CNC lathe. [Image: Self-made quasi-step distance structure chart] The quasi-step gauge has a simple design and is easy to manufacture, making it ideal for in-house production in factories. It can be used to test various CNC equipment, including lathes, machining centers, and milling machines. The distance between adjacent end faces can be customized based on the specific needs of the enterprise. Additionally, the measured spacing between the end faces does not have to be an integer. According to Paragraph 5.4 of the "Evaluation Method," the target position Pj = (J-1)t + r, where J is the target position number, t is the pitch (an integer not equal to a multiple of the drive screw lead), and r is any decimal value. Thus, the spacing of the measuring surface on the gauge meets the requirements of the "Evaluation Method."

Clear Tape

Clear Packing Tape,Transparent Tape,Clear Bopp Packing Tape,Clear Sealing Tape

Dongguan Guanhong Packing Industry Co., Ltd. , https://www.tapegh.com