How to judge the accuracy of CNC machine tools?

Introduction

In the manufacturing process of CNC machine tools, precision is a key indicator to measure product quality, which is directly related to the processing performance and service life of the machine tools. As a manufacturer of CNC machine tool accessories, the precision of our CNC machines must be strictly controlled in every link, from design and development to production and manufacturing, and then to final inspection. The following aspects are about how to judge machining accuracy.

1. Positioning of the test piece in a vertical machining center

The test piece should be located in the middle of the X stroke and placed along the Y and Z axes at an appropriate position suitable for the positioning of the test piece and the fixture and the tool length.

2. Fixing of the test piece

The test piece should be conveniently mounted on a dedicated fixture to achieve maximum stability of the tool and fixture. The mounting surfaces of the fixture and the test piece should be flat.

The parallelism of the test piece mounting surface and the fixture clamping surface should be checked. A suitable clamping method should be used so that the tool can penetrate and machine the full length of the center hole. It is recommended to use countersunk screws to fix the test piece to avoid interference between the tool and the screw. Other equivalent methods can also be used. The total height of the test piece depends on the selected fixing method.

3. Material, tool and cutting parameters of the test piece

The material, cutting tool and cutting parameters of the test piece are as follows:

(1)Cutting speed: cast iron parts are about 50m/min; aluminum parts are about 300m/min.

(2)Feed rate: about (0.05~0.10)mm/tooth.

(3)Cutting depth: the radial cutting depth of all milling processes should be 0.2mm.

4. Dimensions of the test piece

If the test piece is cut several times, the outer dimensions are reduced and the hole diameter is increased. When used for acceptance inspection, it is recommended to use the final contour processing test piece size consistent with that specified in this standard to accurately reflect the cutting accuracy of the machining center. The test piece can be used repeatedly in the cutting test, and its specifications should be kept within ±10% of the characteristic dimensions given in this standard. When the test piece is used again, a thin layer of cutting should be performed before a new fine cutting test to clean all surfaces before testing.

Conclusion

As a manufacturer of CNC machine tool accessories, the accuracy of CNC machine tools is directly related to the quality of our products. The products we deliver to customers must have excellent accuracy performance. Only by constantly pursuing the improvement of accuracy can we win the trust and recognition of customers.