## 3 Materials and Methods
### Inspection  
To ensure the device's conformity with the project specifications, rigorous metrological control was performed using a Hexagon RA-7312 3D measuring arm (Manufacturer: Hexagon Manufacturing Intelligence (a division of Hexagon AB), City: Stockholm (corporate headquarters of Hexagon AB), Country: Sweden). This coordinate measuring system, characterized by a precision of 5 \(\upmu\)m + L/40 mm (where L is the length in mm), with a maximum permissible error of 18 \(\upmu\)m, allowed for the precise evaluation of the device's dimensional and geometric characteristics.  
Figure 18 presents the experimental setup used for the control and validation of the support jaw.  
During this process, the relevant surfaces of the jaw were probed to determine the dimensional and positional deviations, which are critical for ensuring the correct positioning of the specimen during machining.  
Figure 19 illustrates the experimental setup for the control of the support jaw-specimen assembly.  
Figure 16: Clamping of the semi-finished product in the vice for the finishing operation of the profile.  
Figure 17: Machined support jaw, with screws mounted, ready for assembly.  
* Primary locating surface: The surface on which the semi-finished product is positioned, thus defining the machining angle of the specimen.
* Third locating surface: An auxiliary reference surface used in the measurement process.
* Cutting surface: The surface of the specimen resulting from face milling, whose roughness will be evaluated after machining with the barrel tool.
* Programming angle: The angle between the side and cutting surfaces, representing the programming angle of the cutter.
* Complementary angle to programming angle: The angle between the bottom and cutting surfaces, used for verifying angular deviations.
* The control was focused on the key surfaces of the support jaw, those that directly influence the precision of the specimen's positioning and, consequently, the programming angle of the barrel tool.
* The measured parameters included
* Surface flatness: The maximum deviation of each surface from the theoretical flatness, important for ensuring correct seating of the specimen and machining accuracy.  
Figure 19: Dimensional verification of the support jaw-specimen assembly.  
Figure 18: Control setup for the inspection of the support jaw.  
* Angular accuracy: The conformity of the machined angles with the designed nominal values, essential for adhering to the programming angle of the cutter.
* To ensure a correct interpretation of the results, a precise definition of the reference surfaces used in the measurements was made:
* Bottom: The base surface of the jaw parallel to the machine tool table plane.
* Side: The lateral surface of the jaw, perpendicular to the fixed jaw of the vice and the machine tool table. This surface defines the direction of the transverse feed and will be used as a reference for establishing the origin on the Y-axis during specimen machining.
* Top: The upper surface of the jaw, parallel to the machine tool table. This surface will serve as a reference for establishing the origin on the Z-axis.
* Secondary locating surface/Stationary Jaw: The surface that defines the direction of the longitudinal feed and will be used for establishing the origin on the X-axis.