2024 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2024): Special Session: Multi-Axis and Robotic-Enabled Additive Manufacturing
Program Organizers: Joseph Beaman, University of Texas at Austin
Monday 1:30 PM
August 12, 2024
Room: 412
Location: Hilton Austin
Session Chair: Joseph Kubalak, Virginia Tech
1:30 PM
Robotic Convergent Manufacturing of Large Format Structures: James McNeil1; Michael Carney1; Dennis Harwig1; Stacey Smith1; Travis Peterson1; 1EWI
Robotic convergent manufacturing combines additive, subtractive, and transformative processes to drive digital manufacturing of complex part features. This project developed arc DED build procedures using a large format hybrid 11-axis robotic gantry and a smaller 9-axis system. The systems have a wide range of capability, including: arc-DED GMA-P welding systems, robotic finishing and machining, and laser-powder DED. Developing proper workflows, process procedures, and the supporting process controls necessary to demonstrate full scale builds can be challenging within these systems. However, the capabilities that can be brought to one part without further tooling and setup provides unique capabilities for developing and printing additively manufactured parts. Videos and demonstrations of builds and workflows will be provided for a variety of part features and material types. Convergent manufacturing provides a unique way forward for agile reconfiguration of robotic systems for use in repair and additive manufacturing.
1:50 PM
Aluminum Wire Arc Additive Manufacturing Weld Parameters and Path Improvement: Hutchison Peter1; Kamren Sargent1; Joshua Penney1; Tony Schmitz1; 1University of Tennessee, Knoxville
Wire arc additive manufacturing (WAAM) is commonly used for low volume production and repair of metal parts due to its reduced time and cost compared to casting. The selection of appropriate weld parameters is required to ensure fusion between beads, reduce porosity, and decrease defects. Additionally, path adjustments affect the heat distribution within each layer and the part dimensional accuracy. Gas metal arc welding (GMAW) tests were conducted with a KUKA KR 50 R2500 robot equipped with a Fronius welder to determine parameters for cold metal transfer (CMT) welding of 4943 aluminum. Using the CMT 1368 Adv (v1.2.0) synergic line, sufficient fusion between beads and weld quality was observed. Slicing programs were made in Rhinoceros7 and were used to modify the welding path so that dimensional inaccuracies from thermal gradients were reduced. WAAM of large aluminum components provides efficient production of complex parts for commercial and defense applications.
2:10 PM
Design of a Convergent Electroslag Additive Manufacturing (ESAM) System: Adam Stevens1; Paritosh Mhatre1; Dave Hebble2; Luke Pinion1; Alex Roschli1; Jesse Heineman1; Rangasayee Kannan1; Peeyush Nandwana1; Soumya Nag1; Sarah Graham1; Charles Savage1; Tom Richardson2; Daniel Allford2; Brian Post1; 1Oak Ridge National Laboratory; 2Arc Specialties
Electroslag strip cladding is under investigation as a method for high-productivity metal additive manufacturing. Due to the presence of a molten slag layer, adaptation of electroslag strip cladding to electroslag additive manufacturing (ESAM) requires development of methods for defining and containing the slag layer during solidification. This presentation covers initial convergent (multi-process) experiments exploring the use of gas tungsten arc welding perimeter beads to contain the ESAM slag layer in an additive process and includes mechanical and microstructural characterization of same. The design of an automated multi-robot system for convergent arc-ESAM is then presented along with projected performance metrics.
2:50 PM
Pros and Cons of Industrial Robotics in Additive Manufacturing: Michael Geuy1; Lance Streuber1; Yifei Li1; Ilya Kovalenko1; Jay Martin1; 1The Pennsylvania State University
Advances in non-planar, multi-axis, and continuous-fiber inlay in material extrusion additive manufacturing increasingly demand active nozzle orientation control. Industrial articulated robot arms are commonly implemented for repetitive manufacturing tasks and these arms are becoming a common choice of motion platform for additive manufacturing given their ubiquity and flexibility. Here we explore the pragmatic benefits and challenges of using industrial robotic arms for extrusion additive manufacturing. While robotic arms from established manufacturers are highly capable, recent offerings are more easily integrated and safer, while providing the same or improved capabilities as the more traditional models.
3:10 PM Break
3:40 PM
Fused Deposition Modeling Using Orthogonally Configured Cartesian Printheads: Hadi Noori1; Joshua Short1; Ben Warner1; Gavin Shepherd1; Duron Scruggs1; Laura Southard1; He Bai1; Reza Azarfam1; Soroosh Farsiani1; 1Oklahoma State University
A multi-axis extrusion-based 3D printer was developed with two printheads configured orthogonally, adding counter-gravity printing capability. Process settings, including layer height and print speed, could be customized for each printhead. Printheads could be controlled independently to manufacture products with customized spatial properties. The CAD models of products were sliced into at least two segments to prevent collision between printheads and designs. The primary printhead needed to start to create a part of the design as a substrate for the secondary printhead, which stated its action when enough space was provided for its motion. Subsequently, the primary printhead could continue constructing on a part built by the secondary printhead.The printheads were utilized to manufacture three-point bending samples comprising two longitudinal segments bonded in their thickness direction. The results showed that the segment configuration with respect to the loading direction can significantly influence flexural strength and crack initiation.
4:00 PM
Large-Scale, Conveyor Belt-Assisted Robotic Additive Manufacturing: System Design and Toolpath Planning: Joseph Kubalak1; Nathaniel Root1; Katie Dingler1; Alex Ryan1; Brook Kennedy1; Christopher Williams1; 1Virginia Tech
The design of gantry-based additive manufacturing (AM) platforms defines the maximum build volume; printed parts must always be smaller than the gantry, making AM of large components challenging. However, by using a conveyor belt as the print surface, the build volume is extended infinitely along one axis by conveying previously-printed geometry out of the working envelope. Further, pairing the conveyor belt with a six-axis robotic arm provides additional flexibility to tailor the layering orientation throughout the build. This presentation discusses the design of a conveyor belt-assisted robotic AM system and explores the effects of different toolpathing strategies for fabricating parts that exceed the robot arm's reach. First, we present a novel toolpath planning algorithm that enables printing on a continuously moving belt. Second, we discuss effects of discontinuous, multi-planar printing of part sections on final mechanical properties. A comparative analysis of the methods' throughput, dimensional accuracy, and performance is offered.
4:20 PM
Extending Beyond Gantry Direct Ink Write Printing Using Robotics: Robert Lahaie1; James Hardin2; Anesia Auguste2; 1UES, inc; 2Air Force Research Laboratory
Direct ink write (DIW) is a commonly used technique in polymer additive manufacturing, where filaments of material are deposited to build 3D structures. The development of desktop robotic arms have enabled the capability for conformal and support free printing within the DIW field; However, the research on the effects of printing with a robotic arm vs a gantry system on the material properties is limited. We investigated the effects of DIW with a robotic arm on the printability and material properties of an anisotropic material as compared to a gantry system. Using a carbon fiber epoxy composite ink, samples were mechanically tested, 3D scanned to investigate geometrical accuracies, and CT scanned to analyze fiber alignment to elucidate the role of nozzle orientation, kinematics, and gravity on the material properties. This research will provide insight into deposition technique effects on material properties, providing a better understanding of printing onto complex surfaces.
4:40 PM
Algorithm to Generate Toolpaths for Printing on Non-developable Surfaces: David Trauernicht1; Steve Barnes1; Dave Keicher1; Denis Cormier1; 1Rochester Institute of Technology
Printing 2D features (e.g., circuits, antennas, or images) onto non-developable surfaces requires that the 2D feature distorts to some degree. UV mapping typically segments the surface, flattens it, maps the feature onto the segments, then reconstructs the surface. Continuity of features across boundaries of the segments can be a challenge. An algorithm will be described that does not segment the surface, but instead uses minimization of distances in a plane versus distances along the curved surface to distort the 2D feature as little as possible. The algorithm for remapping the 2D coordinates to new 3D coordinates for printing onto the surface will be described. Wrapping of the printed features around a surface using a user-defined preferred axis will also be described. Triangulation of the STL surface can present challenges when printing depending on the printing technique. A method of smoothing the surface via local curvature estimation will be discussed.
5:00 PM
Exploring Trace Geometry on Angular Surfaces with Drone-based 3D Printing: Alex Pan1; Jacob Garifalis1; Suyog Ghungrad1; Azadeh Haghighi1; 1University of Illinois Chicago
Additive manufacturing using flying mobile robots is still in its infancy yet offers tremendous potential for enhancing print flexibility. The aerial maneuver capability of 3D printing flying robots makes them extremely beneficial for the in-situ repair of large-scale structures, such as bridges, and for accessing areas typically beyond the reach of static or z-constrained robotic additive manufacturing solutions. Although successful prints have been demonstrated with 3D printing flying robots, the dimensional accuracy of the print is still unclear. The lack of this knowledge limits the potential of aerial 3D printers. This work presents an experimental approach to explore the deposited trace geometry of an aerial drone-based 3D printer with conformal printing capabilities over angular surfaces. A design of experiments approach is adopted to study the effect of various parameters such as angle of the print surface, angle of extrusion nozzle and extrusion pressure on the accuracy of print.