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In 3-axis milling, cutting force analysis represents one of the main methods to increase the quality and productivity of the process. In this context, cutting force shape gives information of both monitoring and prediction of the cutting process. However, the cutting force shape is not unique, and it changes according to the cutting strategy, tool geometry, and cutting parameters. This paper presents a comprehensive approach to predict and classify cutting force shapes in 3-axis milling operations. In detail, the proposed approach starts by classifying the cutting force shapes for a single fluted endmill (i.e., single flute force shape), and, considering how the single flute force shapes may overlap one another, it extends the classification to a general multiple-fluted endmill. Moreover, the method provides, through analytical equations, angles, and magnitude dimensionless parameters of each key point, describing each shape classified. Finally, the proposed approach was experimentally validated through several milling tests in different cutting conditions. [ABSTRACT FROM AUTHOR]

The turning of thin-walled components is a challenging process due to the flexibility of the parts. On one hand, static deflection due to the cutting forces causes geometrical and dimensional errors, while unstable vibration (i.e., chatter) could compromise surface quality. In this work, a method for fixturing optimization for thin-walled components in turning is proposed. Starting from workpiece geometry and toolpath, workpiece deflections and system dynamics are predicted by means of an efficient finite element modeling approach. By analyzing the different clamping configurations, a method to find the most effective solution to guarantee the required tolerances and stable cutting conditions is developed. The proposed method was tested as a case study, showing its application and achievable results. [ABSTRACT FROM AUTHOR]

The set-up of machining parameters for non-ferric materials such as wood and wood-based materials is not yet defined on a scientific basis. In this paper, a new rapid experimental method to assess the specific cutting coefficients when routing isotropic and orthotropic wood-based materials is presented. The method consists of routing, with different depths of cut, a given material previously machined to a round shape after having it fixed on a dynamometric platform able to measure the cutting forces. The execution of subsequent cuts using different depths of cut allows the calculation of the specific cutting coefficients. With the measurement being done during real routing operations, a method to remove machine vibrations was also developed. The specific cutting coefficients were computed for the whole set of grain orientations for orthotropic materials and as an average for isotropic ones. The aim of this paper is to present and validate the whole method by machining selected materials such as Polytetrafluoroethylene—PTFE (isotropic), Medium Density Fiberboard—MDF (isotropic), beech Laminate Veneer Lumber—LVL (orthotropic) and poplar LVL (orthotropic). The method and the proposed analysis have been shown to work very effectively and could be used for optimization and comparison between materials and processes. [ABSTRACT FROM AUTHOR]

• A method to identify depths of cut in 2.5-axis milling is proposed. • Normalized frequency spectrum of total cutting force is exploited. • The method does not require information about cutting direction or force coefficients. • Analytical equations to predict cutting force spectrum are provided. • The method could lay the ground for a force-based cutting parameters monitoring system. This paper presents a novel approach to identify both radial and axial depth of cut in 2.5-axis peripheral milling operations using cutting force signals analysed in the frequency domain (i.e., cutting force spectrum). In detail, the method exploits the normalized cutting force spectrum, which is directly obtained through dedicated analytical formulations, to estimate depths of cut. The proposed approach is promising and differs from previous works since it does require nor the cutting force coefficients or cutting force direction neither a dedicated instrumentation. The developed method was numerically and experimentally validated in different cutting conditions. The results obtained show that depths of cut are identifiable with a maximum absolute error less than 0.4 mm, proving that the proposed approach could be a solid foundation for a force based cutting condition monitoring system in peripheral milling. [ABSTRACT FROM AUTHOR]

In peripheral milling, surface accuracy is crucial for the quality of the machined components, and it is one of the reasons why milling is still essential in the manufacturing field. Nonetheless, both static phenomena, like tool deflections, and dynamic issues such as forced vibrations, impact on the accuracy of the components causing surface errors. In this context, the prediction of surface error is an important tool to guarantee surface accuracy and increase productivity at the same time. This paper presents a novel approach to predict surface location error in 2.5-axis peripheral milling operations considering the stiffness variation along the axial depth of cut. The proposed approach discretizes the endmill in small discs, and it evaluates analytically the cutting force along the cross-feed direction for each disc in the frequency domain. Then, tool dynamic stiffness, which is expressed in terms of frequency response function (FRF), is computed considering the stiffness variation along the tool axis. Finally, the presented approach couples the cutting forces with the tool stiffness, and it evaluates surface error along the tool axis. The method was experimentally tested in different conditions to verify its effectiveness and its limits. The results obtained show how static and dynamic aspects and stiffness variation contribute to surface errors in peripheral milling operations. [Display omitted] • Surface location error along the axial depth of cut in 2.5-axis milling is accurately predicted. • Analytical formulations for cutting forces in frequency domain are proposed. • A RCSA-based approach to predict tool FRF variation along the axial depth of cut is presented. • The proposed approach considers both forced vibrations and variation of the tool dynamic stiffness. • Accuracy of the method is proven by experimental validation on several milling tests. [ABSTRACT FROM AUTHOR]