A comprehensive support-free slicing method library for variable posture additive manufacturing

Support-free slicing technology plays a critical role in additive manufacturing by reducing costs and simplifying post-processing. However, due to the complexity of geometric features, existing support-free slicing strategies often lack the necessary universality in industry. This paper proposes a method library comprising six basic support-free slicing methods to enhance the applicability and computational efficiency. The general methods in the library include facet-based methods and voxel-based methods, the former facilitates rapid slicing, while the latter enables the re-decomposition of complex structural parts. For parts that cannot be covered by general methods, customized methods are developed. These include constructing a support bridge for multi-direction slicing of overhanging regions in an arch model and extracting the optimal central axis for internal channels to achieve precise channel decomposition. Additionally, the methods in the library can be flexibly combined. By recognizing surface features and incorporating manual intervention, models can be decomposed into multiple sub-models, with the most computationally efficient method is matched to each sub-model. The layers and tool-paths of each sub-model are generated by the optimal method. Four typical models are deposited without any support in a five-axis printer to verify the feasibility of the proposed methods.