Block-based inner support structure generation algorithm for 3D printing using fused deposition modeling

Among 3D printers, fused deposition modeling (FDM) printers are widely used because of their low cost and simplicity. However, long manufacturing time remains a major problem in such printers. The inner support structure is the primary cause of the long manufacturing time. Hence, we propose a new inner support structure generation algorithm to reduce the manufacturing time and the amount of material used to fill the interior of an object. In addition, the proposed algorithm ensures self-printability. The proposed algorithm uses three-dimensional block partitioning based on an extension of the conventional two-dimensional pattern method. These blocks are obtained by dividing a given object using arbitrary planes. The inner support structure can be redefined as a set of contact surfaces or cut faces between blocks. To minimize the inner support structure, the inner unit blocks are merged into a combined block. To eliminate flat roof points, the object is then divided such that each block has a minimal cut surface area. This splitting process ensures self-printability of the inner support structure. Using this splitting process, any model of complex shape can be stably stacked without a supplementary support structure for the inner support structure. By comparing with the conventional method, the proposed method is shown to considerably reduce manufacturing times and material waste.