# Influence of Ball-End Milling Strategy on the Accuracy and Roughness of Free Form Surfaces
## 1 Introduction
It lists the advantages of 5-axis milling over (3 + 2)-axis milling, which include increased milling accuracy, shortened cutting time, extended tool life, increased functional surface properties of the machined surface, and reduced and better orientation of the cutting forces. When comparing the machining accuracy in 3-axis, (3 + 2)-axis, and 5-axis milling, the highest accuracy was achieved in 5-axis simultaneous milling. The (3 + 2)-axis milling yielded more favorable surface roughness values. The comparison was performed on a sample with a shaped surface made of aluminum alloy EN AW 6060. A zig zag (linear) strategy with conventional and climb milling and different tool axis angles was used. The predicted residual material in the CAM system for the group of samples processed using 5-axis milling corresponds closest to the actual residual material. These results are valid for CAM systems. Similar comparisons indicate the quality of computational algorithms used in CAM systems. Ref. [5] compares 3- and 5-axis milling in machining basic geometric shapes: ball, cylinder, and pyramid. It is stated that both milling methods achieve almost the same shape deviations, but the deviations achieved by 5-axis milling are smaller and the quality of the machined surface is better. Linear and spiral strategies were employed. A mathematical model for predicting the roughness of a milled surface is defined in [6]. The authors state that after finishing operations with ball-end mills, milled surfaces present two types of inequalities: cusps caused by the cutting width (ae) and scallops caused by the feed per tooth (fz). [PERSON] et al. [7] describe a virtual machine model that is usable not only in simulations of milling processes, but also for accurate determination of milling time and surface condition after machining. This model makes it possible to influence the accuracy, quality, and productivity of machining by setting the interpolator. Surface properties are a significant measure of the quality of the finished component because they affect properties such as the dimensional accuracy, friction coefficient, wear, post-processing requirements, appearance, and cost. Deviations from the required shapes or dimensions are caused by machining-tool errors, improper workpiece clamping and deformation, and worn or improperly clamped tools. The surface roughness is one of the primary requirements for the design of engineering products. It is a widely used product-quality indicator and is usually measured when a component is already machined [8]. Authors present a series of mathematical models for determining the surface roughness (R\({}_{\mathrm{z}}\)) for commonly used shape-milling methods (vertical, push, pull, oblique, oblique push, and oblique pull) and determines the influence of the milling method on the resulting surface roughness in ball-end milling. Aluminum alloy EN AW 7075-T6 was selected as a workpiece material. The quality of a surface produced by milling also depends on technological parameters, such as cutting conditions and coolants. The evaluation of three cooling methods when machining aluminum alloy EN AW 6061 is described in [9]. The authors conclude that the MQL cooling technique can be used as a better alternative to the dry or flood cooling method. The machining of freeform surfaces is generally associated with the concept of machining strategy. The milling strategy used depends on the relative positions of the cutting tool and workpiece, as well as the kinematics of the cutting tool during operation. There is increasing emphasis on product quality and process efficiency, which indicates that the industry requires high-efficiency machining strategies for machining freeform surfaces. Therefore, strategies must satisfy the growing demand for surface accuracy and integrity, shorter machining times, and reduced cutting forces. Reference [10] defined a simulation and optimization system based on body modelling integrated with a CAD/CAM system.