Mechanical strength of chunk-based printed parts for cooperative 3D printing

Cooperative 3D printing is an emerging technology that envisions a large number of mobile 3D printing robots working cooperatively to finish a print job. To support the cooperative 3D printing, we have developed a chunk-based printing approach. In chunk-based printing, the workpiece is first divided into small chunks and then the chunks are allocated to an army of robots for printing. Although the chunk-based printing has demonstrated its capability in speeding up the printing process and scaling up the printing size, the bond strength at chunk joint is still unclear. The lack of this knowledge limits the potentials of the chunk-based printing. To this end, we assess the tensile strength of chunk-printed parts and compare their strength against those normally printed by traditional layer-based 3D printing. We first identify the parameters associated with chunk-based printing, such as the chunk slope angle and the chunk overlapping depth, which can directly influence the bond strength. Then, the design of experiment is performed based on different combinations of these parameters. Based on the experimental results, we conclude that the existence of chunk joint will not weaken the strength for the chunk-based printed parts under the proper selection of chunk-based printing parameters. The results therefore prove the validity of the chunk-based printing and provides the fundamental knowledge support for the chunk-based cooperative 3D printing of the future.