Optimizing fused deposition modelling: the impact of geometrical slicing parameters on mechanical properties

This comprehensive study explores the intricate world of 3D printing, with a focus on Fused Deposition Modelling (FDM). It sheds light on the critical factors that influence the quality and mechanical properties of 3D printed objects. Using an optical microscope with 40X magnification, the shapes of the printed beads is correlated to specific slicing parameters, resulting in a 2D parametric model. This mathematical model, derived from real samples, serves as a tool to predict general mechanical behaviour, bridging the gap between theory and practice in FDM printing. The study begins by emphasising the importance of geometric parameters such as layer height, line width and filament tolerance on the final printed bead geometry and the resulting theoretical effect on mechanical properties. The introduction of VPratio parameter (ratio between the area of the voids and the area occupied by printed material) allows the quantification of the variation of geometric slicing parameters on the improvement or reduction of mechanical properties. The study also addresses the effect of overhang and the role of filament diameter tolerances. The research continues with the introduction of 3D FEM (Finite Element Analysis) models based on the RVE (Representative Volume Element) to verify the results obtained from the 2D model and to analyse other aspects that affect mechanical properties and not directly observable with the 2D model. The study also proposes a model for the examination of 3D printed infill structures, introducing also an innovative methodology called “double RVE” which speeds up the calculation of mechanical properties and is also more computationally efficient. Finally, the limitations of the RVE model are shown and a so-called Hybrid RVE-based model is created to overcome the limitations and inaccuracy of the conventional RVE model and homogenization procedure on some printed geometries

3D printed custom gas cam for race bike application using Progrip® lock on grips mod.708

Background: The “drive by wire” mechanism for managing the throttle is not applied to every modern motorcycle, but it is often managed through a steel wire. Here, there is a cam on the throttle control. Its shape allows the throttle opening to be faster or slower and its angle of rotation, required for full opening, to be greater or less. The maximum angle a rider's wrist can withstand depends on numerous musculoskeletal mobility factors, often limited by falls or surgery. Methods: Using a Progrip knob with interchangeable cams allows the customization of a special cam profile, to ensure the best engine response to throttle rotation and ergonomics for the rider. The use of FEA software and lattice structures, allows to realize a lightweight and efficient design, targeted for fabrication with additive manufacturing technologies. Results: The cam was manufactured by exploiting MSLA technology. Finally, a dimensional inspection procedure was performed before assembly. The main result is to have obtained a lighter and cheaper component than the original. Conclusions: This study has allowed the design of a mechanical component consisting of innovative shape, light weight, and ergonomics. Furthermore, it demonstrates the effectiveness in the use of lattice structures to enable weight optimization of a component while minimizing the increase in its compliance

Reverse Engineering of a Racing Motorbike Connecting Rod

The following scientific paper aims to analyze in detail the methodology for reverse engineering of a racing motorcycle connecting rod. The objective is to start with a product available on the market as a spare part, reconstruct its CAD model with a high standard of accuracy, then proceed with lightening modifications to arrive at a new, improved design. The innovative aspect of the procedure lies in the fact that in order to ensure accuracy on the order of a tenth of a millimeter during reconstruction, it was decided to use a FARO articulated arm laser to scan the component’s outer surface. By taking advantage of appropriate redesign CAD software (Geomagic Design X), a reconstruction can proceed within the high standard of accuracy imposed. In conclusion, the modifications made through material removal allow an improvement in product efficiency, ensuring high performance

An Innovative Ford Sedan with Enhanced Stylistic Design Engineering (SDE) via Augmented Reality and Additive Manufacturing

The design of an E segment, executive, midsize sedan car was chosen to fill a gap in the market of the Ford brand and to achieve the goal of innovation looking towards the future. Ford has not owned an E-segment flagship sports sedan for years, since the historic 1960s Falcon. Starting from the latter assumption and considering that the major car manufacturers are currently investing heavily in E-segment cars, it is important to design a new model, which has been called the Eagle. This model proposed here is to fill the gap between Ford and other companies that are already producing sport cars for the electric sector and to complete Ford’s proposal. The presented methodology is based on SDE, on which many design tools are implemented, such as Quality Function Deployment (QFD), Benchmarking (BM), and Top Flop Analysis (TPA). A market analysis follows in order to identify the major competitors and their key characteristics considering style and technology. The results are used to design an innovative car. Based on the most developed stylistic trends, the vehicle is first sketched and then drawn in the 2D and 3D environments for prototyping. This result leads to the possibility of 3D printing the actual model as a maquette using the Fused Deposition Modelling (FDM) technology and testing it in different configurations in Augmented Reality (AR). These two final applications unveil the possibilities of Industry 4.0 as enrichment for SDE and in general rapid prototyping