Effects of table position correction on 3D-printing accuracy and quality

BACKGROUND: This article discusses the impact of corrections that take into account the real position of the 3D printer table (its curved geometry) on the accuracy of the resulting products and the quality of their surface in the end direction. The main problem that is addressed in the study is that the actual geometry of the 3D printer table is curved (different from the plane). In this case, difficulties arise as with ensuring the fixation of the printed part on the table - when applying the first layers of filament, the model may be separated from the table. In addition, there is a factor of technological inheritance when the initial error of the table is copied to the product. This paper proposes an approach that makes it possible to obtain the real geometry of the table at the stage of pre-setting the printer and make adjustments to the control program in order to improve the surface quality and accuracy of the resulting parts. AIM: this study consists in the development and implementation of a methodological approach to eliminating the effect of the geometric error of the 3D printer table on the dimensional accuracy and surface quality of additive products. METHODS: As the main process equipment, printers were used that print products with material supply through the extruder nozzle. The model for calculating the geometric parameters of the table and the magnitude of corrections is based on linear algebra and the least squares method. Table point coordinates were obtained using a contact type sensor integrated into the printer head. Measurement of surface roughness of products was carried out on a profiler, and dimensions - using a micrometer. RESULTS: Based on the least squares method, a mathematical model was developed that approximates the plane of the 3D printer table taking into account the real curvature that was measured by the sensor. Software has been developed that allows calculating the amount of nozzle position corrections during printing, which are entered into the control program at the setup stage. Studies of the sizes of the resulting products have shown that the use of corrections makes it possible to increase the accuracy by 2-3% and improve the surface roughness of parts from Ra12.5 to Ra5.0 microns. The stability of the printing process by accuracy parameters using Shewhart diagrams was also analyzed. CONCLUSION: Studies show that the use of a methodological approach, which consists in calculating and introducing corrections that take into account the actual position of the printer table, makes it possible to significantly increase the accuracy of dimensions and improve the surface quality of the resulting parts.