Altprint Program for Additive Planning by Extrusion: Application in PRUSA Architecture Equipment, Evaluation of Functional Parts Under Cyclic Loading, and Redesign of an Assistive Device with Codivilla Spring

• Grant number: 25/04996-0
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: June 30, 2025
• End date: October 29, 2025
• Field of knowledge: Engineering - Mechanical Engineering - Manufacturing Processes
• Principal Investigator: Zilda de Castro Silveira
• Grantee: Ricardo Henrique Dias
• Supervisor: Jorge Lino Alves
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: Universidade do Porto (UP), Portugal
• Associated to the scholarship: 23/11404-7 - Development and implementation of continuous path for 3D printing based on variable strands width filling, BP.IC

Abstract

This project, part of the BEPE-Fapesp internship with an expected duration of four months, aims to share expertise in the broad field of Additive Manufacturing between the research groups of Lab 3D, from the Department of Mechanical Engineering at the São Carlos School of Engineering, University of São Paulo, and the LDPS (Laboratory for Product and Service Development) research group at FEUP (Faculty of Engineering, University of Porto). Within two research lines, Additive Planning and Design for Additive Manufacturing, the activities to be developed at LDPS-FEUP will include: a) adapting the Altprint program for equipment with a PRUSA direct-drive architecture, which is widely used in Europe; b) designing a geometry aimed at evaluating cyclic loading conditions to assess the flexible beams generated by the Altprint program; c) preparing, conducting, and analyzing the results of cyclic loading tests on this geometry using customized equipment (MultiTest 2.5-dv); d) refining the design of an assistive device (orthosis with a Codivilla spring) and performing anatomical digitization using the Artec Eva 3D scanner. The additive manufacturing of functional parts, whether for replacement purposes or not, requires reproducibility and reliability as key design attributes. Variations in the stiffness (or flexibility) of parts manufactured using additive techniques arise from research involving functional gradients, topological optimization, or multimaterial use. This project follows an alternative research approach in additive planning: controlled variation of rheological parameters and extrusion-based additive process parameters directly within the slicing and printing software. This approach enables the generation of a one-dimensional set of beams within geometries, allowing for localized and user-defined flexibility. Thus, the main objective of this project is to expand the range of desktop 3D printing architectures supported by the Altprint program. To achieve this, printed beam sets in flexible regions will undergo cyclic loading tests using a customized continuous-trajectory geometry made from a commercial polymer-based filament (PLA - Polylactic Acid). Following this, the maximum number of cycles until the failure of the first beams will be estimated. This procedure will enhance the redesign robustness of the Codivilla Spring assistive device, while the use of LDPS-FEUP's professional 3D scanner will generate an anatomical geometry to be manufactured upon the researcher's return to Brazil, marking the completion of the Scientific Initiation project.Keywords: Additive Manufacturing, Fused Filament Fabrication, FDM, Functional Parts, Dynamic Loadings, Stiffness Variation, Open Software.