No matter what we do, we need a standard so that we can do things well, especially when it comes to precision parts machining. According to my understanding, on a lathe, the rotary motion of the workpiece and the linear or curved motion of the tool are used to change the shape and size of the blank and machine it to meet the requirements of the drawing.
Ordinary machine tools are increasingly difficult to meet the needs of processing fine parts. CNC fine parts machining mainly includes ultra-fine turning, mirror grinding and grinding.
The primary condition of CNC fine parts machining is the accuracy of its process benchmark, the benchmark on the mechanical drawings are indicated by a specific benchmark symbol with a circle in capital letters A, B, C, D, etc.. When the datum symbol is aligned with the face and the extension of the face or the scale boundary of the face, it indicates that the face is the datum. When the datum symbol is aligned with a scale line, it is based on the centerline of the solid indicated by the scale. The process accuracy mentioned above is a more abstract term.
Mounting datum refers to the precision used to determine the orientation of a part in a component or product during mounting. The measurement datum refers to the specification used to measure the scale and orientation of the machined surface when the part is inspected. The positioning datum is the datum used to position the workpiece in the machine tool or fixture during machining. the process datum of CNC fine parts machining is the condition to ensure the production of high quality parts.
