# Development Workflow for Manifolds and Fluid Components Based on Laser Powder Bed Fusion
## 2 Methodology Development
If the position of an installation space for a hydraulic component was specified as variable in the analysis of functional surfaces, its position in the AM design shall regard the following three aspects. Its position within the hydraulic logic, the assembly and accessibility with the required tools, and finally an efficient nesting of the valves, sensors, and motor. There are several software solutions [22] available, which create two-dimensional nesting solutions for a set of defined geometries. For a re-design, it is important to question existing component positions, as conventional manufacturing constraints may have lost relevance through AM. Once these elements are positioned, the orientation of the part within the build space of the LPBF system is to be chosen. This decision has a fundamental influence on the design of subsequent geometries, the manufacturing quality of the part, the necessary amount of support material, and finally, the economic efficiency of the build job. After the technical feasibility of the selected orientation is proven by a manufacturing simulation, a preliminary economic assessment is conducted in task seven. The outcome of this decision sequence is often a compromise of minimum manufacturing time, best manufacturing quality, mechanical properties, necessary support material, and manufacturing costs [17]. It shall therefore be repeated iteratively until the best compromise for the given boundary conditions is found. Additionally, if no such compromise can be found, the decision knot at this early stage of the development process prevents the usage of further resources on unpromising concepts and questions the suitability of AM for the specific project [5]. As the main elements are usually standardized installation spaces and threads, the DfAM potential lies mainly in the design of the hydraulic interconnection of the installation spaces. The channel diameter is to be selected according to the present fluid flow of the application [23]. Circular channels with a diameter greater than 7 mm require internal support structure [16; 18; 24]. As the complex channel design makes these structures inaccessible, they must be avoided. Multiple studies provide restrictive design guidelines for non-circular channel cross-sections [16; 18; 25]. Additionally, an appropriate wall thickness must be selected, which resists high, cyclic pressure load over the complete lifetime as specified in the requirements list [16; 26; 27; 28]. The design complexity enables channels that can be designed conformal to existing walls and installation spaces, sharing a single wall, and saving thereby AM-material and manufacturing process time. Through this design flexibility, the size of a manifold is not limited by the channel layout anymore. As most functional surfaces require a high surface quality and geometric precision, they must be post-processed with subtractive processes [18]. In task nine, the necessary machining offset, registration features, and clamping positions are added to the geometry to enable precise machining. Again, these features shall be designed according to restrictive design guidelines presented in the literature [25; 29]. Further, referencing strategies for subtractive operations on defined registration points shall be established at this point. All geometric elements designed in tasks five to nine serve a specific function. Even though these elements are designed under consideration of restrictive DfAM guidelines and the chosen orientation, the geometric complexity requires compromises in the usage of support for certain elements. However, it is a major intention of DfAM to minimize the usage of supports, as they require extensive manual labor for their removal [25]. Consequently, most of the necessary support structures shall be replaced by design elements, for example, thin walls, which are not removed and serve as additional stiffening elements. Support-critical areas are identified by build-preparation software [30] and then replaced by geometric elements in the design software iteratively.