Decision basis for multi-directional path planning for post-processing reduction in material extrusion

Reducing support structures in Material Extrusion (ME) of Additive Manufacturing enables lowered post-processing efforts and enhanced use in industrial applications. This study provides a decision basis for multi-directional path planning strategy to print parts on multi-axis printers without the use of support structures. Research solutions for different limitations of ME systems are examined. The combination of Flat and Curved Layer Slicing, Adaptive Slicing, Load-Capable Path Planning and Multi-Axis Slicing enables printing a multi-directional demonstrator part. The part’s build structure consists of form elements (features) with varying build directions depending on the transition areas between them. A proof-of-concept on a three-axis printer shows the ability of a multi-directional printing method for multi-axis printer systems. Interfaces between features require print parameter adjustment to obtain the desired mechanical properties. Tensile tests are performed to evaluate the mechanical load capacity at connecting areas between features of standard specimens. Geometrically complex parts (3D) are printed in conventional ME systems without support and improved characteristics through the multi-feature path planning strategy. Each feature is printed according to geometrically determined requirements representing a successful proof-of-concept. Results show that further testing is required for the effects of mechanical resistance at connection areas. Adaption of the path planning strategy is needed to reduce occurring defects.