Accuracies of 3D printers with hard and soft materials

Purpose This study aims to systemically evaluate morphological printing errors between computer-aided design (CAD) and reference models fabricated using two different three-dimensional printing (3DP) technologies with hard and soft materials. Design/methodology/approach The reference models were designed to ensure simpler and more accurate measurements than those obtained from actual kidney simulators. Three reference models, i.e. cube, dumbbell and simplified kidney, were manufactured using photopolymer jetting (PolyJet) with soft and hard materials and multi-jet printing (MJP) with hard materials. Each reference model was repeatably measured five times using digital calipers for each length. These values were compared with those obtained using CAD. Findings The results demonstrate that the cube models with the hard material of MJP and hard and soft materials of PolyJet were smaller (p= 0.022, 0.015 and 0.057, respectively). The dumbbell model with the hard material of MJP was smaller (p= 0.029) and that with the soft material of PolyJet was larger (p= 0.020). However, the dumbbell with the hard material of PolyJet generated low errors (p= 0.065). Finally, the simplified kidney models with the hard material of MJP and soft materials of PolyJet were smaller (p= 0.093 and 0.021) and that with the hard material of PolyJet was opposite to the former models (p= 0.043). Originality/value This study, to the best of authors' knowledge, is the first to determine the accuracy between CAD and reference models fabricated using two different 3DP technologies with multi-materials. Thus, it serves references for surgical applications as simulators and guides that require accuracy.