Ferdinando Vitolo

Flatness, circularity and cylindricity errors in 3D printed models associated to size and position on the working plane

The purpose of this paper is to assess the main effects on the geometric errors in terms of flatness, circularity and cylindricity based on the size of the printed benchmarks and according to the position of the working plane of the 3D printer. Three benchmark models of different sizes, with a parallelepiped and cylinder shape placed in five different positions on the working plane are considered. The sizes of models are chosen from the Renard series R40. Benchmark models are fabricated in ABS (Acrylonitrile Butadiene Styrene) using Zortrax M200 3D printer. A sample of five parts for each geometric category, as defined from the R40 geometric series of numbers, is printed close to each corner of the plate, and in the plate center position. Absolute Digimatic Height Gauge 0-450mm with an accuracy of ±0.03mm by Mitutoyo is used to perform all measurements: flatness on box faces, and circularity/cylindricity on cylinders. Results show that the best performances, in terms of form accuracy, are reached in the area center printable while they decrease with the sample size. Being quality a critical factor for a successful industrial application of the AM processes, the results discussed in this paper can provide the AM community with additional scientific data useful to understand how to improve the quality of parts which may be obtained through new generations of 3D printer.

A Digital Pattern Approach to the Design of an Automotive Power Window by means of Object-Oriented Modelling

The paper deals with a digital pattern (DP) approach to the design of an automotive power window, using object-oriented modelling. Therefore, the paper faces the designing of a mechatronic system by using an integrated approach to product development. Then, Dymola/Modelica environment is used as a tool of a decision support system that makes possible the DP approach. The paper briefly sum up the results of simulations related to a power window system characterized by a double bowden sliding mechanism. Finally, the paper highlights the parameters that could be easily integrated in a graphical user interface, aimed to reduce both the development time of new power window system and to increase the accuracy of design activities.

A Digital Pattern Approach to 3D CAD Modelling of Automotive Car Door Assembly by Using Directed Graphs

The present paper deals with methods for product development aimed to support designing activities and to re-use company know-how. The work is addressed to complex products i.e. products characterized by several components and dependencies among them. Then, the paper presents both the methodological approach and the application to the 3D CAD modelling of an automotive car door assembly. The work uses directed graphs and a series of algorithms to provide a Graphical User Interface (GUI) able to support a designer by reducing the development time of new car door assemblies and increasing the accuracy of the design activities. According to a digital pattern approach, the GUI is used to determine the set of changes to 3D CAD models that typically occur in the automotive field, during the development of new car door assemblies.