## 2 Materials and Methods
To commence, the flowmeter's rotor was disassembled and coated with \"AESUB-SPRAY-Black\" (produced by AESUB, located in Recklinghausen, Germany), as shown in Figure 3. This temporary coating transforms glossy surfaces into matte ones that do not reflect light. Such a procedure is necessary because 3D scanners with structured light technology cannot effectively scan glossy surfaces. Approximately 2 to 4 h after the application, which allows sufficient time for the 3D scanning of the rotor, the matte layer, with a minimal thickness of 5-20 \(\upmu\)m, sublimates. Consequently, the coated component requires no further cleaning processes. Following the application of the thin matte coating to the rotor, it was subjected to 3D scanning using the \"EinScan-SP V2\" scanner, manufactured by SHINING 3D, headquartered in Hangzhou, China, as depicted in Figure 4. This scanner generates a virtual point cloud, spatially arranged, which approximates the geometry [35] of the rotor. Figure 3: Coating with “AESUB SPRAY Black”. The 3D scanning of the rotor was conducted in two distinct positions to enable comprehensive coverage of all surfaces. Subsequently, the two resulting geometries were aligned and transformed into a surface 3D model in \"stl\" format, as depicted in Figure 5.  
The \"stl\" format model resulting from the 3D scanning was imported into the parametric 3D modeling software \"SOLIDWORKS 2023 SP 1.0.\" Within this software, various virtual measurements, as depicted in Figure 6, were performed, measurements that would be physically unattainable. Figure 4: The 3D scanning of the flowmeter rotor. Figure 5: The alignment of the rotor geometries and the resulting 3D model in “stl” format. With the precise dimensions of the rotor, obtained through physical and virtual measurements (lengths, diameters, and angles), an accurate 3D model of the rotor was meticulously created in \"SOLIDWORKS.\" This model, as showcased in Figure 7 from various angles and cross-sections, illustrates how space was intentionally allocated for the incorporation of magnets and the shaft, ensuring their permanent integration into the rotor. Figure 8 demonstrates how the precise \"stl\" model resulting from the 3D modeling in \"SOLIDWORKS\" faithfully replicates the geometry of the accurate 3D model. By importing the precise \"stl\" model into \"PrusaSlicer v 2.6.0\" (the slicer software for the 3D printer Prusa SLIS), support structures were added to the model and converted into machine code. Figure 9 illustrates how support was manually applied to the rotor, with a high-density configuration to prevent deformation during the printing process [36] (Figure 10). This step, the conversion into machine code within the 3D printer's slicer software, is a critical one and necessitates careful planning during the creation of the accurate 3D model. The orientation of the part must ensure that no voids are formed due to internal cavities during printing, and additional support must be provided for the initial layers of the printed component. Figure 6: Virtual measurements of the rotor’s geometry in “SOLIDWORKS”. Figure 7: The precise 3D model of the rotor and a cross-section through it. To address the challenge of local deformation at support junctions in parts printed using MSLA technology, several effective strategies can be applied. Among these, the authors resorted to optimizing support structures by minimizing their contact points with the printed part, using appropriate support structures to alleviate stress concentration, adjusting the print orientation and placement to strategically position support contact points, varying support thickness at critical junctions, implementing adaptive algorithms to dynamically adjust support structures based on part geometry, and employing post-processing techniques like sanding or polishing to smoothen affected areas. These combined strategies tailored to the specific part's requirements successfully mitigate local deformation at support junctions, enhancing the quality of parts produced through MSLA technology.