Automated Extraction of 3D Printed Parts From Unfused PA12 Powder Using a One-Shot 3D Printed Compliant Gripper

Automated individual part extraction from powder based 3D printers has the potential to save time and cost compared with fully manual part extraction, or part sorting following automated bulk separation of parts and unfused powder. This work details the development of a novel one-shot 3D printed compliant gripping mechanism, able to extract individual solid parts from unfused PA12 powder. It was found that the unfused powder causes grip slip and instability as well as an increase in the perceived object width. A new toothed digit geometry was created, able to reduce the duration of the instability, and localised vibration was shown to eliminate the initial period of increased strain. A combination of toothed geometry and localised vibration showed a relative strain output on the gripper almost identical to that of the same grasp with no powder present. This allows individual solid parts to be extracted from unfused powder in a known pose, ready for automation of subsequent post-processing steps.