Analysis of the product defect risk caused by the workpiece position error at the installation in a prism

The paper considers issues of assessing the risk of a product defect due to unacceptable errors in positioning surfaces during machining and caused by deviations in the dimensions of workpieces and sample used in setting up the device. Based on analyzing the published studies devoted to the workpiece positioning errors, the need was revealed to expand approaches to determining the risk of product defects by conducting machine experiments to simulate the contact between workpieces and device mounting elements, as well as to consider the joint quality indicators distribution in analyzing the position deviations. The task was set and an example of risk assessment is provided based on analytical calculation of the workpiece limiting positions, as well as the solid-state computer simulation of the technological system elements contact for the case of processing the tee-type part in a CNC milling operation on a machining center with the vertical spindle axis. Based on the results of solving the problem, examples of recommendations are provided for modifying the technological solution aimed at reducing the risk of product defects.