DESIGN AND ANALYSIS OF A LOW COST FUSED DEPOSITION MODELLING MACHIINE

Abstract

There are many notable advantages associated with the use of Additive Manufacturing technology. However, the use of this technology for production of functional engineering components and prototypes is limited in Nigeria. This is majorly due to non-availability of Additive Manufacturing (AM) equipment, lack of exposure to the technology and high cost of importing the machines into the country. This phenomenon had brought about the need to locally develop a Fused Deposition Modelling (FDM) machine for the purpose of manufacturing in Nigeria. A comprehensive design analysis of an FDM machine was done. Stress analysis was carried out using finite element (FE) modelling tool in Autodesk Inventor Simulation package to determine the Von Mises stresses distribution, the displacement and the factor of safety. The simulation result indicated a maximum stress of 3.669 MPa on one of the machine stand. However, the maximum stress value obtained was found to be lower than the yield strength of the material selected for that part. Furthermore, a maximum displacement of 0.04096 mm was observed on one of the machine component. But the effect of the displacement was also considered negligible on the stability of the machine frame. The minimum factor of safety observed from the distribution is 12.537. The temperature distribution and the thermal stress analysis was done, using COMSOL Multi-physics to determine the adequacy of the heat conducting components for use in the FDM machine. The result indicated that a high temperature of 350 K – 385 K is distributed very close to the edges of the heat-bed, while a maximum temperature of 510 K – 530 K is distributed at the pointed end of the hot-end. The results also showed that the maximum thermal stress of about 1.5 x 10-7 N.m-2 is distributed along the diagonals of the heat-bed component, while a maximum thermal stress of 3.5 x 10-7 N.m- 2 is distributed along the length of the hot-end component. However, the maximum thermal stress value obtained in each case is lower than the yield strength of the material selected for the development of that part. Hence, the selected materials for the heat-bed and hot-end were considered suitable for use in the development of the FDM machine. The statics studies of the extruder beam for the FDM machine was carried out in order to determine the maximum deflection of the beam and to determine the suitability of the beam for the design. The maximum deflection was found to be 0.031mm, and was considered tolerable for the designed FDM machine. The estimated cost of developing the designed FDM machine is N 225,500.