Investigation of parameters affecting the roughness and cylindricality of holes in PLA parts made of 3D printing by fused deposition modeling process using response surface method

In this paper, the effects of input parameters on the roughness and cylindricality of a hole were investigated using fused deposition modeling (FDM). The roughness and dimensional accuracy are very important for a 3D printed part. The investigated input parameters are injection speed, solid percentage, and layer thickness. The experiments were designed using the response surface method and 51 PLA samples were printed. To measure the roughness and dimensions of the manufactured products, a roughness-testing machine and a coordinate measuring machine (CMM) were used. The basis of this study is the comparison of roughness and deviation from the center to find the optimal set of the investigated parameters to achieve higher quality.The optimal levels of parameters for the minimum simultaneous roughness (0.016 mm) and cylindricality (5.98 microns) are a layer thickness of 0.1 mm, injection speed of 40 mm / s, and solidity percentage of 15% when the pattern is triangular. The results also suggest that the layer thickness has the strongest effect on the surface quality in comparison with the injection speed and percentage of solidity.