Manufacturing Technology 2026, 26(3):296-306 | DOI: 10.21062/mft.2026.026

3D Printing – Weight Optimization of FDM-Printed Components Using PLA and PETG

Alexandr Fales ORCID...¹, Vít Černohlávek ORCID...¹, Marcin Suszynski ORCID...², Jan Štěrba ORCID...¹, Patrik Balcar ORCID...¹, Marek Makúch ORCID...³, Pavel Houška ORCID...¹

¹ Faculty of Mechanical Engineering, J. E. Purkyne University in Usti nad Labem. Pasteurova 3334/7, 400 01 Usti nad Labem, Czech Republic

² Faculty of Mechanical Engineering, Poznan University of Technology, Poland

³ Faculty of Industrial Technologies in Púchov, Alexander Dubček University of Trenčín. Ivana Krasku 1809/34, 020 01 Púchov, Slovak Republic

Within the framework of my doctoral thesis, the selection of suitable FDM 3D printing parameters for the fabrication of parts for modular educational robotics kits is systematically analysed. The research encompasses both the choice of an appropriate 3D printer and the design and implementation of a series of experimental measurements and mechanical tests aimed at obtaining a sufficiently robust data set for determining the optimal combination of filament materials and printing parameters. These parameters are intended to ensure that the printed parts achieve the required dimensional, weight, and mechanical characteristics while minimizing the need for any subsequent processing (no post‑processing). Special attention is paid to the mechanical properties of the parts, in particular to their behaviour under bending (i.e., deflection), which is typical of the actual use of these components in robotic constructions. From an application-oriented perspective, the economic efficiency of 3D printing is also evaluated in comparison with the purchase of original parts. The key parameter in this research is the requirement to reduce the weight of the printed replica of a robotics kit component, which is directly related to filament consumption and indirectly to print time. Printing time is perceived by schools as a critical factor in terms of operating costs associated with energy consumption, nozzle wear, and potential maintenance costs. The research is situated in the context of educational robotics and the use of 3D printing in primary and secondary school settings. The integration of the complete workflow – from model design, through 3D printing and experimental testing, to the real-world deployment of the parts in robotic constructions with primary and secondary school pupils directly in class – represents a significant motivational factor for students and enables the practical implementation of STEM/STEAM/STREAM methodologies in education. The main technical criterion for the design of parts and the choice of printing parameters is to ensure “printability” without the need for solid infill of the internal volume. This makes it possible to meet the objective of reducing material costs through filament savings, reducing the weight of prints compared to fully infilled parts, and thereby reducing the overall weight of the robotic model’s structure, while at the same time shortening the printing time, which in turn lowers the costs of printing and operating the 3D printer. At the same time, the required dimensional accuracy, target component weight, and sufficient mechanical properties with respect to the intended loading must be maintained. Another requirement under consideration is the technological simplicity and robustness of the printing process, i.e., that the printing of the given parts is feasible even for beginners, with minimal need for intervention in the device settings. The selection of specific parts from the VEX GO and second‑generation VEX IQ robotics kits for analysis and printing was based on the results of previous research published in, which identified suitable components in terms of their mechanical loading, frequency of use, and potential for cost savings through the replacement of original parts with 3D‑printed components.

Keywords: 3D printing, PLA, PETG, Infill density, Educational robotics

Grants and funding:

This article was supported by the SGS grant of J. E. Purkyne University in Usti nad Labem, project No. UJEP‑SGS‑2025‑48‑001‑1, and by the project DigiLab SMART III – Ustecky kraj, registration number CZ.02.01.02/00/22_009/0004316, implemented within the OP JAK programme

Received: December 10, 2025; Revised: March 31, 2026; Accepted: April 20, 2026; Prepublished online: April 29, 2026; Published: June 29, 2026  Show citation