Design and development of a low-cost open-source 3D printer and its single response optimization using polylactic acid (PLA) material

Abstract

Fused deposition modelling fabricates a 3D model from CAD data using a heated tip to extrude thermoplastic material onto a surface layer-by-layer. At present, there are number of commercial 3D printers available. Owing to the high cost, material restrictions and difficulty to study process parameters of commercial 3D printers, an open source 3D printer is designed and developed taking into consideration the cost analysis as well. Design of experiments (DOE) is used with an orthogonal array using three process parameters layer thickness, orientation Infill Orientation and temperature of extruder, to get tensile strength of the specimen. A standard specimen of ASTM D638 made up of PLA material is selected for analysis in 27 experiments where tensile testing is performed to calculate the tensile strength of each specimen. A probability distribution curve is drawn to ascertain the validity of the experiments where the results fall close to the mean value. Using the ANOVA approach and regression model a full quadratic equation is obtained and a graph is obtained which corroborates with the fact that although anisotropic deposition of material results in disparity of tensile strength, but the values fall within permissible limits. The results highlight that in case of PLA material as the layer thickness decreases, the tensile strength tends to increase. It is also to be noted that although layer thickness and orientation angle have been analysed extensively as process parameters compared to temperature the later within the selected range has shown certain inclination towards a typical value. The future scope is to analyse various other process parameters like raster width, raster angle, object orientation, feed rate, infill density, space filling, etc. to give a comprehensible outlook to the study of the process parameters in open source 3D printers using other polymers.