Machining error refers to the deviation degree of the actual geometric parameters from the design ideal value. The smaller the machining error, the higher the machining accuracy. Let's first look at the categories of machining errors.
1. Dimensional error
It is the deviation degree of the actual size of the part from the ideal size after processing. The ideal dimension refers to the average value of the maximum and minimum limit dimensions marked on the drawing, that is, the center value of the dimensional tolerance zone.
2. Shape error
It refers to the difference (or deviation degree) between the actual surface shape of the processed part and its ideal shape, such as roundness and straightness.
3. Position error
It refers to the difference (or deviation degree) between the surface, axis or symmetry plane of the processed part and its ideal position, such as axial degree and positional degree.
4. Surface micro unevenness
The apparent geometric error on the machined part surface, which is composed of small spacing and peaks and valleys. The micro unevenness of part surface is expressed by the evaluation parameter value of surface roughness. Machining error is caused by many error factors in the process system. Such as the principle error of machining method, workpiece clamping and positioning error, fixture and tool manufacturing error and wear, machine tool manufacturing, installation error and wear, machine tool and tool error, force, thermal deformation and friction vibration during cutting, as well as geometric error of blank and measurement error during machining.
