2023 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2023): Process Development: Hybrid and Convergent Processes- Robotics and Hybrid Polymer-metal Processes
Program Organizers: Joseph Beaman, University of Texas at Austin
Monday 1:30 PM
August 14, 2023
Room: 404
Location: Hilton Austin
Session Chair: Zhenghui Sha, University of Texas at Austin
1:30 PM Cancelled
High-precision Camera-based Auto-calibration System for Cooperative 3D Printing: Charith Nanayakkara Ratnayake1; Wenchao Zhou1; Zhenghui Sha2; Ali Ugur3; 1University of Arkansas; 2The University of Texas at Austin; 3Yildiz Technical University
Cooperative 3D printing (C3DP) is an emerging technology that addresses the scalability in size and printing speed in conventional 3D printers by employing multiple 3D printers working together. Accurate positioning and aligning between printers are critical for the success and quality of C3DP. In this study, we have developed a camera-based auto-calibration system for C3DP, which enables more precise and efficient printer calibration. The auto-calibration system utilizes computer vision with a camera that reads ArUco markers placed at known positions on the print bed. With the camera readings, the system accurately calibrates the kinematic parameters of the printers, ensuring the agreement between different printers on the markers' positions thereby spatially aligning them for C3DP. Our results show that this method significantly improves the calibration accuracy, achieving precision beyond 100 microns. In conclusion, the system provides confident printer alignment in C3DP, enhancing the overall efficiency and reliability of the C3DP process.
1:50 PM
Time-optimal Path Planning for Heterogeneous Robots in Swarm Manufacturing: Ronnie Stone1; Junmin Wang1; Zhenghui Sha1; 1University of Texas at Austin
Autonomous mobile robots (AMRs) are gaining popularity in advanced manufacturing. Continuous advances in robotics path planning and the need for increased automation in manufacturing processes have caused a rising demand for integrating AMRs into modern factories. The success of this integration is critical to swarm manufacturing (SM), a new paradigm that employs multiple heterogeneous AMRs to perform a wide range of manufacturing tasks. However, path planning in SM poses unique challenges that must be addressed. Much of the literature on path planning operates under two major assumptions: the environment is static, and the robot's shape is approximated as a center of mass. These assumptions do not hold in SM, where the environment is dynamic, and the robot's orientation could impact the manufacturing task. In this paper, we propose a new methodology to find time-optimal paths in dynamic environments while explicitly considering the shape of AMRs and the obstacles surrounding them.
2:10 PM
Physical Validation of Job Placement Optimization in Cooperative 3D Printing: Cole Mensch1; Wenchao Zhou2; Zhenghui Sha1; 1University of Texas at Austin; 2University of Arkansas
Cooperative 3D printing (C3DP) is an emerging technology designed to overcome the limitations of traditional 3D printing, including speed and scalability. C3DP achieves this by partitioning prints into smaller jobs, e.g., chunks or line segments at each layer, and assigning them to a team of mobile 3D printers that work cooperatively in parallel. Our prior work established a framework for optimizing job placement by connecting geometric partitioning algorithms with path planning and scheduling algorithms. However, this framework was not physically validated. In this paper, we present the first physical validation of the job placement algorithm by chunking and printing two objects using the proposed algorithm. The objects used in the test cases vary in size and complexity, from a small and simple object to a large object with intricate geometry. We demonstrate that our optimized placement algorithm provides results comparable to the physical C3DP system, providing a significant step forward in the practical implementation of C3DP technology.
2:30 PM
Exploring a Supervisory Control System Using ROS2 and IoT Sensors: Matthew Roach1; Josh Penny1; Bradley Jared1; 1University of Tennessee, Knoxville
Whether collecting data from process monitoring sensors or controlling a system of multiple actuators and electrical systems, a powerful supervisory control system must be developed for additive manufacturing (AM) systems. The Robot Operating System version 2 (ROS2) is a set of software libraries that can be used to control robotics systems and has tools for sensor value publishing. This research project is exploring the use of computational nodes connected to process monitoring sensors and robotic or electrical systems to allow for a more in-depth knowledge of the system health and process as well as open the possibilities of process control. These nodes can be connected and controlled by the ROS2 architecture. Work will be discussed exploring the reliability and speed of common AM processes and sensors such as robot controllers and thermal monitoring.
2:50 PM
Lost-PLA Casting Process Development Using Material Extrusion with Low-density PLA: Mohammad Alshaikh Ali1; Orkhan Huseynov1; Ismail Fidan1; Fred Vondra1; 1Tennessee Tech University
The goal of this research is to develop a baseline procedure for lost-PLA casting process of aluminum. Traditional Manufacturing techniques and Smart Manufacturing techniques have their advantages and disadvantages. Integrating the traditional and modern aspects of manufacturing enhances the capabilities of manufacturing. Low-weight PLA is used in a Material Extrusion (MEX) machine to fabricate sacrificial patterns for an aluminum lost-casting process. Different process parameters are tested for both the MEX and casting processes. The MEX process parameters tested are: infill pattern, shell count, top/bottom layers, and print orientation. The MEX process parameter investigation allows to draw conclusions to establish a standard for which parameters are ideal for the casting process. The casting process parameters considered are: aluminum temperature, ceramic coating, and sprue size. The preliminary studies show that this casting process is successful in producing dimensionally accurate aluminum parts by a direct-pour casting process using the suggested MEX process parameters.
3:10 PM Break
3:40 PM
In-situ Electrical Resistance Measurements for Soldering Studies in Hybrid AM: Alexander Pustinger1; Joselin Corral1; Arianna Villegas1; David Espalin2; 1University of Texas at El Paso; 2UTEP - W.M. Keck Center for 3D Innovation
The convergence of additive manufacturing (AM) along with multiple applicable technologies has been shown to augment the functionality of printed parts such that mechanical, electrical, and electromagnetic functions can, for example, reside within the same part. This work used an electrical connector commonly used in satellites to demonstrate a hybrid AM approach by embedding the connector, ultrasonically embedding wires, and laser soldering. The connector was a six-pin Easy-on FFC/FPC connector with a fine pitch and leads of 200-micron width. Resistance measurements were carried out during laser soldering, application of insulation material, and encapsulation with thermoplastic extruded at high temperatures (> 300⁰C). The measurements were made to observe the impact of 1) a laser power profile and 2) thermal input from the extrusion nozzle and heated build environment for diagnostics of low yield or performance. Additionally, temperature history data was collected to coincide with resistance measurements.
4:00 PM
Hybrid Metalized Polymer Core (HMPC), Initial Concept and Design of Lightweight Additively Manufactured Hardware: Shaun Whetten1; Charles Rose1; Michael Kracum1; Jacob Mahaffey1; David Saiz1; Joseph Padilla1; Levi Van Bastian1; John Cochrane1; Raymond Puckett1; Brian Hutsel1; 1Sandia National Labs
Sandia National Laboratories (SNL) builds and maintains some of the world’s most complex testbeds which are reliant on advanced hardware. Given one of the main thrusts at SNL is stockpile stewardship, production of these testbeds is both paramount and incredibly difficult. Traditionally hardware has been designed and manufactured with the classical reductive processes yielding undesirably large amounts of waste material. Further, some hardware cannot be classically machined, and hardware overall is becoming increasingly complex. Given this, we present initial concept design and results of our additively manufactured (AM) Hybrid Metalized Polymer Core (HMPC) concept hardware. Our hybrid design approach is rooted in AM and well suited for mass optimized (lightweight) applications and dramatically increases geometric possibilities. Current research includes directly replacing mission critical hardware for pulsed power applications. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525
4:20 PM
Hybrid Metalized Polymer Core (HMPC) Initial Results of Prototype Mass Optimized Pulsed Power Hardware: Charles Rose1; Shaun Whetten1; Michael Kracum1; Jacob Mahaffey1; David Saiz1; Joseph Padilla1; Levi Van Bastian1; John Cochrane1; Raymond Puckett1; Brian Hutsel1; 1Sandia National Labs
Stockpile stewardship, being one of the main thrusts of Sandia National Laboratories(SNL), requires the worlds most advanced test beds which rely on accurate and predictive models of high energy and density environments. Generation of these extreme environments is incredibly difficult and traditional reductive manufacturing limitations must be overcome. Given this, we present initial results of our additively manufactured Hybrid Metalized Polymer Core (HMPC) mass optimized concept hardware fired on the Mykonos accelerator at SNL. Initial results show no obvious power flow differences given an apples-to-apples comparison of like kind shot conditions and hardware topology propagating > 400 kV at > 600 kA while maintaining a ~ 3X mass reduction. Further work is necessary, but we report HMPC power flow hardware works as intended and is believed to be a viable candidate for next generation pulsed power (NGPP). SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525
4:40 PM
Development of Multimaterial Additive Manufacturing Systems for the Embedded Electronics: Carson Vath1; Kazi Md Masum Billah2; Guhaprasanna Manogharan1; 1SHAPE Lab; 2University of Houston
Hybrid manufacturing for integrating different material systems/structures within additively manufactured structures is of growing interest to the AM community. Current wire deposition system in thermoplastic substrates uses thermal energy to embed the wire which in general leads to surface damage and loss the part integrity. This research develops a wire embedding tool that is designed to embed wire in a photocurable thermoset. Thermoset is relatively stable and does not require heat for implanting wire. This method will have relatively more rapid production rate as the extrusion process can be conducted without any interruptions.
5:00 PM
State-of-the-art Cyber-enabled Physical and Digital Systems Deployed in Distributed Digital Factory Using Additive and Subtractive Manufacturing Systems: Open, Scalable, and Secure Framework: Ranjit Joy1; Sung-Heng Wu1; Usman Tariq1; Sriram Praneeth Isanaka1; Asad Malik1; Muhammad Arif Mahmood1; Frank Liou1; 1Missouri University of Science and Technology
A distributed digital factory (DDF) integrates physical and digital systems, leveraging additive manufacturing (AM) and subtractive manufacturing (SM), to enable the dispersed production of components. Existing work focuses on digital twins, AM and SM systems and some security aspects. Nevertheless, a holistic view of integrating devices with dynamic provisions to invoke digital twins has limited supporting research. This paper will detail cyber-physical and digital systems deployed in DDFs. The components of cyber systems, including AM & SM equipment, sensors, communication protocols, and monitoring software, are covered. Challenges associated with the design and deployment of DDFs, such as security, scalability, and interoperability, are detailed. The assessment emphasizes an open framework for DDF development, allowing system integration from vendors & participants across diverse locations and capabilities. The article also examines the significance of a scalable and secure framework for the implementation of DDFs, which ensures the dependability and availability of on-demand manufacturing.