This study presents an experimental analysis of the dynamic behavior of 3D-printed rotors. The rotors are manufactured using fused deposition modeling (FDM) with ABS material at varying infill densities of 25%, 50%, and 100%, as well as different raster angles of \(0^\circ \) and \(45^\circ \) . The printed rotors are mounted on a test rig, where their dynamic behavior (including vibration amplitude and frequency response) is measured under various operating conditions, specifically changing rotational speeds and different unbalance positions. The experimental results indicate that shafts printed with 100% infill density exhibit behavior similar to that of shafts machined from solid ABS bars. However, as the infill density decreases to 25% and 50%, harmonics at 2 \(\times \Omega \) and 3 \(\times \Omega \) emerge in the vibration frequency spectrum. This effect is further accentuated at a raster angle of \(45^\circ \) . Additionally, the critical speeds of the rotor decrease by an average of 10% as infill density is reduced. These findings are attributed to the increased anisotropy of the shafts resulting from lower infill densities during the manufacturing process.
