Збірник наукових праць

DOI: https://doi.org/10.32515/2664-262X.2025.12(43).2.117-122

Assessment of The Stability of the Axial Positioning of the End Face of a Long Cylindrical Workpiece During Automatic Feeding in a Machine Tool

Dmytro Yaniuk

About the Authors

Dmytro Yaniuk, PhD Student in Applied Mechanics and Mechatronics, Lutsk National Technical University, Lutsk, Ukraine, ORCID: https://orcid.org/0009-0002-9633-0620, e-mail: yanyuk_10719366@lutsk-ntu.com.ua.

Abstract

The aim of the work is to develop a unified methodology for assessing the accuracy of the axial position of the end face after automatic feeding on lathes, which allows for the correct calculation of the probability of falling within the tolerance window based on process data. It also makes it possible to agree on key metrics (μ, σ, Pok, Cpk) and rules for their application, and to determine acceptance thresholds for technological solutions. The paper formulates a production problem for mass processing. Four scenarios for the result of feeding are proposed: without undercutting; with a small allowance; with a large allowance; underfeeding (critical defect). The value Δ is introduced as the deviation from the plane Z=0 and T as half of the bilateral tolerance. A parametric assessment of the axial position accuracy of the bar blank end face is given, and the positioning process capability index Cpk = (T−|μ|)/(3σ) and its interpretation are specified. Cpk thresholds (1.00; 1.33; 1.67; ≥2.00) and their relationship to defectiveness are established for quick decision-making. The methodology provides a metrologically correct and reproducible assessment of the axial position of the end face after automatic feeding, suitable for daily operation. This contributes to the achievement of a targeted reduction in displacement and scatter (μ, σ), which reduces the need for trimming and the associated material and energy costs. The result is a methodology that provides a reproducible assessment of the axial position of the end face after automatic feeding. Controlled reduction of μ and σ reduces the need for undercutting and resource costs. The Cpk thresholds allow comparing bar feeding machines and making decisions on the feasibility of certain engineering actions. In general, the results obtained make it possible to implement automatic process control measures and further expansion.

Keywords

cutting machining, position accuracy model, machining strategy, machining parameters, machining optimization, machine subsystems, spindle unit clamping

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References

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Citations

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