Next, this article will specifically introduce how to eliminate the error of CNC machining spherical surface.
Causes of errors in CNC machining of spherical surfaces
When machining spherical surface and curved surface, due to improper adjustment, it is easy to produce shoulder, shovel back and so on. The main reasons are:
Caused by system gap
In the transmission pair of the equipment, there is a certain gap between the lead screw and the nut. With the increase of the operation time of the equipment, the gap gradually increases due to wear. Therefore, the corresponding gap compensation during the reverse movement is the main factor to overcome the shoulder on the machined surface. The clearance measurement usually adopts the dial gauge measurement method, which needs to control the error. However, it should be noted that the meter base and the meter rod should not extend too high or too long, because during the measurement process, due to the long cantilever, the meter base is easy to move under force, resulting in inaccurate counting and error in the compensation value.
Caused by improper tool selection
In cutting, the tool removes material through the main cutting edge. However, after the arc passes through the quadrant and the arc is tangent to the auxiliary cutting edge of the tool, the auxiliary cutting edge may participate in cutting. Therefore, when selecting or grinding tools, we must carefully consider the wedge angle of tools.
Caused by uneven machining allowance of workpiece
In the process of realizing the design performance of parts, whether the machining allowance of the surface to be machined is uniform is also an important reason for whether the formed surface can meet the design requirements, because the uneven machining allowance is easy to cause "reflection" error. Therefore, for parts with high surface shape requirements, the machining allowance should be as uniform as possible before forming, or the design requirements should be achieved by machining one more surface.
Elimination method of errors in CNC machining spherical surface
During the processing of sphere and surface, the sphere may be larger in the middle and smaller at both ends, or smaller in the middle and larger at both ends. At this time, the radius value of the sphere needs to be controlled. If it is large in the middle and small at both ends, you need to increase the radius slightly. If it is small in the middle and big at both ends, reduce the radius value. Try to control the ball error within 0.05mm.