# Surface Quality Evaluation in the Milling Process Using a Ball Nose End Mill
## 5 Conclusions  
The research aimed to present the effect of finishing strategy on surface topography, surface roughness, and variations in machining curved surfaces. The choice of the specimen shape was based on the wide occurrence of such surface areas in the machining of injection molds and other shape tools where it is necessary to achieve the required quality and accuracy of production with respect to the future shape of the product. Three strategies were evaluated--Constant Z, spiral, and spiral circle, whose paths were programmed in the CAM system SolidCAM. The material used for the experiments was the aluminum alloy AlCu4 Mg. The evaluation of surface topography and surface roughness was carried out at three different specimen locations selected to significantly change the effective diameter of the tool on which the tool comes into contact with the machined surface. The results showed changes in the monitored parameters due to a change in the effective diameter of the cutting tool as well as the influence of the strategy used. To produce specimens with corresponding shapes in terms of topography, the Constant Z strategy is the most suitable, in which uniform tool paths were achieved over the whole height of the specimen. From the experiments carried out, the spiral with discontinuous circle-shaped tool-paths appears to be the most advantageous strategy. Due to the large variation of conditions when machining 3D surfaces, it should be noted that changing the conditions can cause a change in the results. Machining 3D surfaces is a very specific matter with many influencing factors. Only the gradual discovery of the regularities of this process leads to knowledge on the basis of which generally valid conclusions can be formulated. The conclusions presented added to the already-known findings and are helpful for technologists/CNC programmers when planning the technology for the production of similar surfaces. One limitation of the study was the sample size used in the experiment. Since larger dimensions are experienced in the machining of molds and some shaped surfaces, this paper offers only a part of the further research that needs to be conducted to better understand any impact on the machining of these shapes. The following outlines are offered for further study in this area:  
1. Shape surface decomposition focused on a deeper understanding of the influence of milling strategies on surface topography. 2. To compare the machining efficiency when using three-axis and five-axis machining due to changing tool-workpiece contact, resulting in a change in effective tool diameter. This should show better surface properties not only in the case of topography but also in the case of roughness parameters or surface deviations. 3. In the case of five-axis machining, there is an opportunity to investigate the effectiveness of the tilt angle of the tool and thus specify the ideal angle for machining shaped surfaces in five-axis machining with respect to the dimensional and shape accuracy of the part. 4. One further possibility of the study is to change the milling method and use ascending instead of descending milling. 5. Similarly, a topic for further study could be to compare the effectiveness of the overhang length of the tool in the cutting process when machining shaped surfaces, where tool stiffness, cutting forces, and, therefore, tool deflection in contact with the workpiece would be evaluated. Another study could analyze the type of chuck on the precision of production because, in practice, different types are used due to the shape and precision of the part we want to achieve. Comparing conventional strategies with milling strategies known as HSM (High-Speed Machining) is also of importance in the field of mold and surface forming. Conceptualization, J.V. ; methodology, J.V., P.I. and M.D. ; validation, J.V. and M.D. ; formal analysis, J.V. and L.K. ; investigation, J.V. ; resources, J.V. ; writing--original draft preparation, J.V. ; writing--review and editing, J.V. and L.K. ; visualization, J.V. ; J.B. and L.K.