Session Sheet - 2026 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2026): Modeling (CAD, Scan Patterns, Contouring, Slicing, etc.)

2026 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2026): Modeling (CAD, Scan Patterns, Contouring, Slicing, etc.)
Program Organizers: David Leigh, University of Texas at Austin

Tuesday 10:00 AM
August 4, 2026
Room: Brazos
Location: AT&T Center

10:00 AM
Print-Planning Using Edge-Weights and Streamlines for Close Alignment of Toolpaths to Objective-Informed Vector Fields: Joseph McKee¹; Ian Rybak¹; Joshua Green¹; ¹University of Texas at El Paso
    Toolpaths in additive manufacturing can strongly affect surface texture, mechanical performance, conductivity, and more. Previous work closely aligned toolpaths to a target vector field as generated by a Hamiltonian path solver running on a lattice pattern developed from a Delauney mesh with weights of edges based on misalignment to the vector field. Though improved over standard infill patterns, the best aligned edge for any node in the graph could be misaligned by up to 30 degrees. This study assigns node locations using streamlines derived from the target vector field providing increased alignment of edges available for the solver. This graph enabled increased resultant path alignment as demonstrated by tailoring toolpaths to imitate brush strokes using vector fields derived from artwork. These methods improve both the alignment of edges available for path selection and the mean edge-weight throughout, supporting objective-informed toolpaths to address additive manufacturing challenges.

10:20 AM
Adapted S³/S⁴ Deformation Slicing for Support-Free 3-Axis FDM: Joshua Nti¹; Michael Tucker²; Michael Wüthrich³; ¹Ashesi University; ²ETH Zurich; ³ZHAW (Zurich University of Applied Sciences)
    Support-free fabrication on conventional 3-axis FDM systems remains challenging because fixed nozzle orientation limits feasible overhang deposition. The S³/S⁴ non-planar slicing pipelines enable support-free additive manufacturing by deforming a model into a printable geometry, slicing it in the deformed state, and mapping the toolpaths back to the original shape. However, because the original framework was developed for multi-axis systems, it cannot be applied directly to conventional 3-axis FDM. This work adapts the pipeline for Cartesian 3-axis printing. Tetrahedralization, volumetric deformation, and slicing in deformed space were carried over from S³/S⁴ with minor modifications, while inverse toolpath reconstruction required major development, and the overhang-handling strategy was reformulated through constrained rotation-field propagation and distance-dependent rotation limits compatible with 3-axis manufacturability. Results show that the adapted pipeline can generate printable non-planar toolpaths for three benchmark geometries, but breaks down in overhang regions bounded by multiple supported edges, demonstrating both its promise and limitations.

10:40 AM
Residual Stress-Informed Slicing Optimization for Multi-Laser Powder Bed Fusion: Ronnie Frank Pires Stone¹; Tianyu Gao²; Rongxuan Wang²; Zhenghui Sha¹; ¹University of Texas at Austin; ²Auburn University
    Multi-laser powder bed fusion (ML-PBF) is an established additive manufacturing technology adopted in industrial applications due to its capability to fabricate complex geometries with high precision. However, predicting the quality of manufactured parts remains a significant challenge, particularly for emerging material systems such as advanced metals and ceramics that require new process characterization. The difficulty arises from the complex thermo-mechanical physics governing the process, where localized melting and sintering between laser scan tracks strongly influence residual stress formation and final part integrity. Accurately simulating residual stress evolution and the effects of multi-laser path strategies is computationally expensive, limiting the practicality of high-fidelity approaches for design optimization and process planning. In this work, we present an optimization framework based on a lightweight computational model for residual stress prediction in ML-PBF. We demonstrate that the proposed framework achieves strong agreement with physical experiments while offering significant computational advantages compared to state-of-the-art methods.

11:00 AM
Temperature Gradient Mechanism-Based Approach to Reduce Warpage in Overhang Regions Using Beam Shaping in Laser-Based Powder Bed Fusion of AlSi10Mg at High Layer Thickness: David Zentgraf¹; Jonathan Utsch¹; Holger Merschroth¹; ¹TU Darmstadt
    High layer thickness and beam shaping yield the potential to boost productivity in laser-based powder bed fusion of metals (PBF-LB/M). However, residual stresses present a major challenge limiting the application of additive manufacturing. In low-angle overhang regions residual stresses can cause in-situ displacement leading to dimensional deviations and even process termination due to recoater collision. The temperature gradient mechanism (TGM) is often used to explain the development of anisotropic residual stresses based on the high temperature gradients developing in the surroundings of the processing zone. This study investigates the influence of process parameters and scan direction on the dimensional deviations of overhang regions made of AlSi10Mg. Therefore, process parameters are analysed regarding laser return time, melt pool dimensions as influencing factors for temperature gradient and overhang deviation. The findings indicate that a suitable selection of process parameters and scan direction yield the potential to significantly reduce warpage in overhang regions.