Investigation of influence of printing modes on the quality of 6-PSS FDM 3D printed thin-walled parts

Abstract

A 6-prismatic-spherical-spherical (6-PSS) parallel 3D printer with six degrees of freedom was introduced. The motion planning and control method of 6-PSS parallel 3D printer is proposed. The effects of vertical and variable-angle printing modes on the surface quality, porosities, and tensile strengths of printed specimens were investigated. Thin-walled specimens with oblique angles of 0°, 10°, 20°, and 30° were printed in vertical printing mode and variable-angle printing mode. In order to reveal the relationship between the printing mode and the quality of printed parts, the surface roughness and angle errors of the specimens were analyzed by the digital microscope, the internal defects of the specimens were analyzed by the micro-X-ray 3D imaging system, and the tensile strength of the specimens was tested. The results show that the surface roughness of the specimens increased with the increase of the angle. The surface roughness and angle errors of specimens printed in the vertical printing mode were significantly higher than those of specimens printed in the variable-angle mode. For the specimens printed in the two printing modes, the porosity of specimens increased and the tensile strength decreased with the increase of the oblique angle. For the specimens with the same oblique angle, the specimens printed by the variable-angle mode have smaller porosity and higher tensile strength. A ship-shaped thin-walled part was successfully printed on a cylindrical surface, indicating that the real-time variable-angle printing mode of the 6-PSS parallel 3D printer was very flexible.

Keywords

• 3D printing
• FDM
• 6-Prismatic–spherical–spherical
• Thin-walled parts
• Tensile strength