Design for manufacturing of surface to improve accuracy

Title: Design for manufacturing of surfaces to improve accuracy in Fused Deposition Modeling

Authors and full affiliations: Alberto Boschetto, Luana Bottini, Department of Mechanical and Aerospace Engineering, University of Rome La Sapienza, Via Eudossiana 18, 00184 Rome, Italy .

Keywords: Fused Deposition Modeling; Accuracy improvement; Design for manufacturing .

Purpose: The aim of this work is the development of a virtual model preprocessing in order to compensate for the deterministic behavior found in the Fused Decomposition Modeling.

Methodology: The idea, in order to compensate the deterministic dimensional deviation introduced during the physical fabrication, is to offset this starting surface by considering a sphere R in radius around the generic point P. The offset surface is generated as the envelope of all the spheres centered in each point of the surface. This mathematical operation corresponds to the displacement by R of the point P along the normal . Starting from the equation of a generic point of the offset surface by doing various calculations, which are found in the whole article, we arrive at the final formulation . The application of this equation to all the surface points allows obtaining a deformed model that permits to compensate the deviations introduced by the physical fabrication. Then the abovementioned methodology has been applied to three case studies: a cylinder, a spherical joint and a fan blade.

Benefits: With this method it’s no necessary to fabricate artifact and perform measurement in order to gain the model information and it can be directly used before CAM environment.

Findings: All the components have been defined by mathematical formulations and fabricated before and after the application of the methodology. The performed dimensional measurements pointed out a marked reduction of the dimensional deviations after the DFM: both for simple and complex geometries the pre-processing of the virtual model permitted to obtain dimensional values very close to nominal ones.

Grafical Abstract:

Full reference: Alberto Boschetto, Luana Bottini, Selective Laser Melting of a 1U CubeSat structure. Design for Additive Manufacturing and assembly, Robotics and Computer-Integrated Manufacturing , Volume 37, February 2016, Pages 103-114.

Link: https://www.sciencedirect.com/science/article/abs/pii/S0736584515000848