It is difficult to process a sphere with a complete shape on a common machine tool. Use the dividing head and the top plus two turning tools to operate, but only half a sphere can be processed. Only with CNC milling machine can it be done accurately. Spherical milling cutter is used for envelope forming.

As we know, when CNC lathe processes a sphere, its arc trajectory is completed by the arc interpolation function of two linear coordinates (x, z). As long as we pay attention to the error of NC positioning accuracy of these two linear coordinates (x, z), we can control the roundness of arc trajectory of arc interpolation.

It should also be noted that the circular interpolation of CNC lathe is completed by the simultaneous movement of X and Y linear coordinates, and the movement of X coordinate has a reversing process, which will make the reverse clearance error of coordinates affect the circular trajectory, thus affecting the roundness of the machined sphere.

Alas, this kind of question is difficult for financial personnel to answer in the financial column. Fortunately, I used to be a worker.