# Optimized One-Click Development for Topology- Optimized Structures +
## 4 Discussion  
The objective of this article was to show the competitiveness of \"one-click\" developed TO prototypes in comparison to more conventional approaches. Therefore, finite spheres are used to add manufacturing constraints during the optimization. Since using an absolute strictness in preventing manufacturing conflicts may not always be expedient, it is reasonable to control the manufacturing constraints within certain limits. The final chosen settings are based on numerical convergence behavior and also on the common practice in AM. Hence, it is assumed that the settings in Table 3 show a good mixture of numerical convergence behavior and increased manufacturability of the design proposal. It is important to emphasize here that while in AM support structures can be tolerated, undercuts in casting processes are non-tolerable. It is further shown in Table 4 that the chosen settings lead to the configuration with the least printing time and also requires the least material in production.  
Nevertheless, the trade-off of the relative volumes between the final STL volume and the needed plastic volume in production is important to mention. This trade-off is an effect of using shelled parts, as it is standard in fused filament fabrication. Hence, methods as presented in [20], which consider shelled AM parts directly for TO, must be the subject of future work. Summing up, in terms of manufacturability, the one-click optimization method leads to design proposals (MaSmo), which are better suited for AM than the other configurations.  
The used test setup in Figure 10 is an abstracted critical load case for the presented application example. Due to this fact, the chosen setup is qualified to evaluate the various configurations' mechanical performances. Regarding the testing results in Figure 16, it is important to stress that the MaSmo configuration was the least noisy. In addition, MaSmo and redesigned are comparable and both better than smoothed in terms of maximal forces. Since the used TO approach is a hybrid optimization for stiffness and strength, it is assumed that TO configurations can bear about 75% of the reference's maximum force, which is met quite accurately by MaSmo and redesigned with 74% of the maximum force. In terms of stiffness, compared in Figure 21, the \"one-click\" optimized MaSmo configuration shows the best result, which corresponds to 52% of reference's stiffness.  
These results assume that the presented \"one-click\" optimization approach is competitive to conventional TO with redesign of the design proposals, as it achieves comparable results for the maximum force and slightly better results for the part stiffness. Therefore, the developed approach allows the manufacture of topologically optimized prototypes in AM directly with a minimum of needed user inputs and is a nearly fully automated design process for the rapid production of prototypes. Since only solid parts are considered, it is an essential objective of future work to integrate graded porosity in combination with unit cells or triple periodic minimalized surface structures as shown in [25] into the \"one-click\" optimization approach in order to be more sophisticated towards AM. In addition, an improvement in the post-processing of the TO results using techniques like support vector regression [28] can further enhance the framework's usability.