The article examines the influence of 3D printing speed and layer thickness on the accuracy of functional dimensions of a part-eight wall prism with 5 holes-one in the centre and 4 in the periphery. For printing the samples, ABS material was used, which is one of the main materials for the production of machines and parts. A portal measuring machine with the highest accuracy was used to effectively perform the task of measuring deviations from the size of the sample. Due to the large volume of experimental results, they were averaged to minimize error and processed using statistical processing software. An accurate regression model was obtained and the printing parameters were optimized.