Influence of Print Orientation on Surface Roughness in Fused Deposition Modeling (FDM) Processes

Abstract

In the present paper, we address the influence of print orientation angle on surface roughness obtained in lateral walls in fused deposition modelling (FDM) processes. A geometrical model is defined that considers the shape of the filaments after deposition, in order to define a theoretical roughness profile, for a certain print orientation angle. Different angles were considered between 5° and 85°. Simulated arithmetical mean height of the roughness profile, Ra values, were calculated from the simulated profiles. The Ra simulated results were compared to the experimental results, which were carried out with cylindrical PLA (polylactic acid) samples. The simulated Ra values were similar to the experimental values, except for high angles above 80°, where experimental roughness decreased while simulated roughness was still high. Low print orientation angles show regular profiles with rounded peaks and sharp values. At a print orientation angle of 85°, the shape of the profile changes with respect to lower angles, showing a gap between adjacent peaks. At 90°, both simulated and experimental roughness values would be close to zero, because the measurement direction is parallel to the layer orientation. Other roughness parameters were also measured: maximum height of profile, Rz, kurtosis, Rku, skewness, Rsk, and mean width of the profile elements, Rsm. At high print orientation angles, Rz decreases, Rku shifts to positive, Rsk slightly increases, and Rsk decreases, showing the change in the shape of the roughness profiles.

Effect of Printing Parameters on Dimensional Error, Surface Roughness and Porosity of FFF Printed Parts with Grid Structure

“…The great influence of layer height on surface roughness of FDM printed parts has been reported by different authors [ 22 , 26 , 27 ]. In the present work, the lowest Ra value achieved in the lateral walls of the parts that were considered in the present research was around 3.9 µm when low layer height, low temperature and a high speed are selected.…”

Analysis of AM Parameters on Surface Roughness Obtained in PLA Parts Printed with FFF Technology

“…In addition, roughness is greatly influenced by the measurement direction. The higher the inclination of a wall is, the higher the theoretical value of the Ra parameter becomes [ 12 , 13 ]. Regarding other roughness parameters, in a previous study with PLA cylindrical parts, it was found that, as a general trend, slightly negative Rsk (skewness) values are obtained in lateral walls of printed parts, corresponding to slightly sharp valleys and rounded peaks.…”

How levelling and scan line corrections ruin roughness measurement and how to prevent it

“…In contrast to method-specific artefacts, e.g. tip convolution in the contact methods 26 that affect directly the statistical results across different scales 27 , 28 , effects related to finite area are universal. They would impact even ideal measurements in which the measured profile perfectly traces the surface topography.…”