The article describes a method for calculating the motion trajectory of a turning tool on a numerically controlled machine to compensate elastic strain when processing a raw part. When sharpening rotary bodies with low rigidity, elastic strain occurs under the action of the cutting force Py, that has a negative impact on the accuracy of the machined surface. As a result, a fault appears in the barrel-shaped and saddle-shaped form, or a combination of these faults, depending on the rigidity of the machine and its individual parts. Based on a mathematical model of elastic strain with a constant cutting depth, this fault had been determined, which was subsequently compensated by the use of a modified trajectory. Thus, when processing, the required diameter is obtained with minimal defects, which in turn will have a positive impact on the reduction of the processing steps of the entire detail, as well as the reduction of mold defect and improving the quality of part process.