Design and Analysis of a Desktop Multi-Axis Hybrid Milling-Filament Extrusion CNC Machine Tool for Non-Metallic Materials

Abstract

Hybrid Manufacturing technologies enable the manufacturability and high manufacturing efficiency of innovative part designs comprising high complexity features which could not otherwise be manufactured in a single or a small number of steps. This study proposes the design of an industrial-grade low-cost fully automated multi-axis hybrid Additive and Subtractive CNC machine for non-metallic parts. It combines operations of a six-axis CNC machining center with a six-axis extrusion 3D printer with automated tool head change for processing parts made of polymer and special 3D printing materials (e.g., carbon fiber reinforced filaments). The design process includes static, dynamic and harmonic response Finite Element Analysis to optimize its structural strength and at the same time to reduce machine component costs down to a few thousand euros for all included components and subsystems, thus making it viable for industrial purposes. In investigated loading scenarios, analysis results show that at the brim of a 200 mm diameter round machine table, even at its most unfavorable angular positions, maximum deformation was no more than 0.24 mm, with a factor of safety in the magnitude of 10 to 20 while applying cutting force profiles with amplitudes up to 100 N, which exceedingly satisfies structural specifications for the proposed machine design operation.

Hybrid FFF/CNC: An open source hardware & software system

“…1 In research area, the combination of those technologies has been widely practiced [5] and the process is usually carried out using an existing platform (CNC) by mounting an extruder in place of a cutting tool [6] , [7] , [8] , [9] , [10] . However, papers can be found where multi-axis hybrid process is carried out using robots [11] , [12] , [13] , specific hybrid machines designs are proposed and made available [8] , [14] or where a 3D printer is directly used for hybrid purposes [15] . Some studies specifically dedicated to this discipline are starting to be published and address the various challenges raised by this new process: the integration of the fused layer modeling process into a CNC architecture designated for subtractive manufacturing [6] , methods to remedy the lack of inter-layer adhesion after machining phases [16] , the benefits in terms of productivity and the savings on raw materials [9] , the correlation between material deposition strategy and the machinability of the green part in 3D MIM-like printing [9] .…”

Hybrid Additive Manufacturing of Parts with Relatively Complex Geometry by 3D Printing in Segments with Uniform Thickness, Variable Height Per Radius, and Constant Filament Feed Rate

“…However, problems related to deformation and strength for products manufactured with these technologies remain unresolved [1,2,3,4,5,6,7,8,9,10] Numerically controlled machine tools, industrial robots have a geometry and accuracy far superior to those of a 3D printer, and in the case of 5-axis machines or robots, parts of greater complexity than 3-axis ones can be produced, with significantly reduced time and material consumption. [11 ,12, 13, 14].…”