Edge quality in fused deposition modeling: I. Definition and analysis

Abstract

Purpose-To discuss the problem of the geometric accuracy of edges in parts manufactured by the FDM process, as a preliminary step for an experimental investigation. Design/methodology/approach-Three geometric variables (inclination, included and incidence angle) were defined for an edge. The influence of each variable on the geometric errors was explained with reference to specific causes related to physical phenomena and process constraints. Findings-Occurrence conditions for all causes were determined and visualized in a process map, which was also developed into a software procedure for the diagnosis of quality issues on digital models of the parts. Research limitations/implications-The process map was developed by only empirical considerations and does not allow to predict the amount of geometric errors. In the second part of the paper, experimental tests will help to extend and validate the prediction criteria. Practical implications-As demonstrated by an example, the results allow to predict the occurrence of visible defects on the edges of a part before manufacturing it with a given build orientation. Originality/value-In literature, the geometric accuracy of additively manufactured parts is only related to surface features. The paper shows that the quality of edges depends on additional variables and causes to be carefully controlled by process choices.

Fused deposition modelling: a review

“…Results showed a close relationship between surface finish, with build direction. Armillotta and Cavallaro (2017) proposed an empirical model to forecast the existence of visible imperfections on the edges of a part before manufacturing it with a given build orientation (Armillotta et al , 2017a). Alsoufi and Elsayed (2017) investigated the influence of factors on the surface finish of parts made up of PLA+ material and found that layer height and nozzle diameter were significant in terms of part surface roughness.…”

Review and New Aspects in Combining Multipoint Moulding and Additive Manufacturing

“…Therefore, the positioning of the component in the building space is an important process parameter regarding to the surface quality of the finished part, as all edges of the part that are not oriented parallel or perpendicular to the building platform, will show a more or less pronounced staircase effect [30]. ARMILLOTTA et al [75], therefore, develop an improved calculation model to predict the surface quality more precise, depending on the position of the component in the building space. This model can be used to reduce the staircase effect and improve the surface quality.…”

Hatching for 3D prints: Line-based halftoning for dual extrusion fused deposition modeling

“…These artifacts cannot be well described with existing quality metrics for FDM, like (global) geometric accuracy and/or surface roughness (i.e. [21,22]), both which do not capture the effect of the geometric variation on the perceived gray scale. Even though the sagging of vertical surfaces is employed within the range of 0.2 mm, we found the human eye can easily detect these inaccuracies, especially in regions with a uniform gray scale.…”