INFLUENCE OF PRESS-FIT DIMENSIONS ON REPEATED ASSEMBLY OF BALL BEARINGS INTO 3D PRINTED HOUSINGS

Abstract

This study investigates the mechanical behaviour of 3D printed PET-G housings designed to accommodate steel 6000-2RS ball bearings, a common component in hobbyist and rapid prototyping applications. Two housing variants were manufactured using identical printing parameters and material, differing only in internal diameter—undersized by 0.2 mm and 0.1 mm, respectively, since it is impossible to include tolerances in this form of additive manufacturing. The goal was to simulate interference fits and assess how repeated assembly and disassembly cycles affect fit integrity and material deformation. Each bearing was press-fitted into its respective housing and removed across five consecutive cycles using a texture analyser, an advanced device capable of applying and precisely measuring forces up to 5000 N. Insertion and removal forces were recorded throughout the experiment. Dimensional measurements of the housings were taken both before and following the cycles to evaluate permanent deformation or loss of tolerance. The results highlight differences in required assembly and disassembly forces between the two under-sizing approaches, providing practical insights for design tolerances in 3D printed assemblies where repeated mechanical interfacing is expected. These findings contribute to best practices in additive manufacturing design for mechanical fit components.