## 3 Materials and Methods
### Device Design  
The device ensures a significantly higher rigidity of the semi-finished product compared to an additional axis attached to the CNC machine table or a manually operated dividing head. Such an axis can be purchased as an accessory for the CNC machine if it has been pre-equipped with an interface to drive additional axes. Tests already performed with an additional axis, or a manual dividing head have indicated a significant decrease in rigidity and a pronounced negative influence on the obtained Ra (surface roughness). \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Chemical Composition (AIMS 03-05-012 REV 1)**} & **Specific** & **Measured** \\  & **Value** & **Values** \\ \hline Si & Max 0.15 & 0.12 \\ Fe & Max 0.2 & 0.08 \\ Cu & 1.2–2.0 & 1.7 \\ Mn & Max 0.1 & 0.01 \\ Mg & 2.1–2.9 & 2.2 \\ Cr & 0.18–0.28 & 0.2 \\ Zn & 5.1–6.1 & 5.8 \\ Ti + Zr & Max 0.15 & 0.04 \\ Each & Max 0.05 & \\ Total & Max 0.15 & \\ Mechanical characteristics (AIMS 03-05-012 REV. 1) & Specific Value & Measured values \\ Tear resistance (MPa) & Min 540 & 597 \\
0.2\% Yield strength (MPa) & Min 480 & 545 \\ Elongation (\%) & Min 6 & 10 \\ Hardness HB & Y.P. & 165 \\ Electrical conductivity (MS/m) & & 21.6 \\ Elastic Modulus (MPa) & & 71,160 \\ Extruded thickness (mm) & & 3 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Chemical composition and mechanical characteristics of alloy 7175. Figure 2: Al7175 semi-finished product used to make the device. The device was designed with the purpose of ensuring the optimal orientation of the semi-finished product (specimen) in relation to the programming angle of the barrel tool and the movement axes of the 3-axis CNC machine tool. An essential criterion in the device's design was to ensure the rigid clamping of the semi-finished product during the machining process, to maintain stability and processing precision. Furthermore, the device was equipped with probing surfaces, integrated into the design to facilitate the precise definition of the device-specimen coordinate system, a system fundamental for the correct generation of the machining program. The correct positioning of the semi-finished product is critical for each programming angle of the barrel tools. To ensure this positioning, the device was designed with an interchangeable locating element, adaptable to the specific programming angle. This approach allows for the use of a single fixture body with different locating jaws; each precisely machined for a specific barrel tool programming angle. Thus, the device allows for the orientation of the semi-finished product in accordance with the programming angles of the cutters used in the tests, namely 18\({}^{\circ}\), 20\({}^{\circ}\), and 42.5\({}^{\circ}\). Figures 3-5 illustrate the 3D CAD models and assembly views of the device, highlighting the main components such as the vice, the jaw, and the specimen. These visual representations detail the assembly method of the components and the spatial relationships between them. Figure 3 presents a 3D CAD overview of the device, including the vice, the designed jaw, the specimen, and the barrel tool, with a programming angle of 42.5\({}^{\circ}\). Figure 4 provides a CAD detail of the locating jaw, a key component for positioning the specimen. It also indicates the locating, orienting, and supporting surfaces of the specimen, as well as the probing surfaces used during CAM programming. The listed surfaces are also important during the machining of the specimen by cutting. Figure 5 shows a 3D view of the assembled device, giving a clear perspective of the final configuration. Figure 3: Three-dimensional CAD assembly picture with view—designed trough—test specimen—barrel end-milling cutter (programming angle 42.5\({}^{\circ}\)). It is important to note that the initial models (Figure 1) underwent modifications during the manufacturing process, with the addition of fixing holes to enhance the rigidity of the assembly and ensure a solid attachment to the fixed jaw of the vice.