Investigation on the Scale Factor applicable to ABS based FDM Additive Manufacturing

Fused deposition modelling (FDM) is an RP process that can automatically construct the physical models from computer aided design (CAD) data, usually layer by layer addition, without any tooling and fixture use. In this paper, the effect of six process parameters viz., bed temperature, nozzle temperature, print speed, infill, layer thickness and number of loops each at three level was studied on the dimensional accuracy and surface roughness of fused deposition modelling build parts. Design of Experiments was done using Taguchi method and an array of L27 was selected for experimental runs. Experimental results shows that the measured dimensions are always more than the CAD dimension along the Z-direction but dimensions along X and Y directions are less than the CAD dimension. Percentage deviations in each axis were found out and also surface roughness along top and vertical surface. Both the results are combined using Grey Relational Analysis for the optimization of the multi-response result. Suitable scale factors in each direction were found out and applied to the CAD dimensions to compensate for the dimensional deviations. This work is a part of an ongoing research on popularizing digital manufacturing in Indian precision casting industries. (c) 2017 Elsevier Ltd. All rights reserved.