Browsing by Subject "fused deposition modeling"
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Item 3D-Printable Electronics - Integration of SMD Placement and Wiring into the Slicing Process for FDM Fabrication(University of Texas at Austin, 2016) Wasserfall, Florens; Ahlers, Daniel; Hendrich, Norman; Zhang, JianweiSeveral approaches to the integration of wires and electronic components into almost every existing additive fabrication process have been successfully demonstrated by a number of research groups in the last years. While the pure mechanical process of generating conductive wires inside of a printed object has proved to be feasible, the design, integration, routing and generation of toolpaths is still a laborious manual task. In this paper, we present a novel approach to place and wire SMDs in a three-dimensional object, based on schematics generated by conventional PCB design tools such as CadSoft EAGLE. Routing wires in an object for FDM manufacturing requires certain knowledge about the printer’s properties to meet the extruder characteristics, avoid non-fillable regions and electric shorts. Correspondingly for the slicing of conductive wires, the software must respect appropriate channel widths, avoid interrupted traces and ensure proper endpoints serving as contact pads for the SMDs. To fulfill those requirements, we implemented the design and routing software as a native extension of an existing slicing software. The user works in a three-dimensional representation of the final extruder toolpath, augmented by the routing information. The actual computing step is executed at the layer level by manipulating the polygons which represent the two-dimensional object topology and toolpath for each single layer, allowing the routing algorithm to avoid the generation of nonprintable traces. We successfully designed and printed some test objects including a force-sensor prototype, demonstrating a significant improvement in the usability and efficiency over manual solutions.Item Additive Manufacturing of Carbon Fiber and Graphene – Polymer Composites using the technique of Fused Deposition Modelling(University of Texas at Austin, 2016) Girdis, Jordan; McCaffrey, Matthew; Proust, GwénaëlleAdding micro or nano-carbon reinforcements to polymers enhances their mechanical and electrical properties. In this paper, the effects of the addition of short carbon fibres (SCF) and graphene into acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) polymer to create composite filaments for fused deposition modelling (FDM) are investigated. After creating carbon polymer composite filaments, using a commercial 3D printer, samples were printed and tested for mechanical and electrical properties. The measured values for these composites were compared to those obtained for pure ABS and pure PLA. It was found that by using only 2% SCF it was possible to achieve a 22% increase in tensile strength with no significant impact on printability. With addition of graphene, PLA was made to be conductive. These results show the feasibility of developing new materials for 3D printing that will create structurally sound and conductive designs.Item Analyzing the Tensile, Compressive, and Flexural Properties of 3D Printed Abs P430 Plastic Based on Printing Orientation Using Fused Deposition Modeling(University of Texas at Austin, 2016) Hernandez, R.; Slaughter, D.; Whaley, D.; Tate, J.; Asiabanpour, B.To achieve the optimum functionality and mechanical properties in the AM-based parts, it is vital to fully characterize parts under static mechanical loadings (tension, compression, and flexure) that are built in different orientations. This research reports the results of the compression (ASTM standard D695), 4-point flexure (ASTM D790), and tensile (ASTM D 638 Type I) tests on the ABS plastic specimens that are designed according to the ASTM standards and are built in different orientations using the uPrint SE Plus 3D printer. This study examined the effects that printing 3D parts in different orientations (build angles) has on the mechanical properties of ABS P430 plastic. A total of 45 samples (15 tension, 15 compression, and 15 flexure) were printed in 5 orientations; 0 degrees in the XY plane, 45 degrees in the XY plane, 90 degrees in the XY plane, 45 degrees in the Z plane, and 90 degrees in the Z plane. The hypothesis was that the samples printed 0 degrees in the XY plane would be the strongest in compression and flexure, and also have the greatest modulus of elasticity. The samples printed 90 degrees in the XY plane were predicted to be the strongest in tension, having the largest tensile strength and lowest modulus of elasticity. The findings showed that printing 90 degrees in the XY plane resulted in the highest tensile strength compared to the other orientations, but not by a significant margin. Printing 0 degrees in the XY plane significantly increased the compressive and flexure strengths of the material compared to other orientations.Item Approaches to Geometric Data Analysis on Big Area Additively Manufactured (BAAM) Parts(University of Texas at Austin, 2016) Dreifus, G.D.; Jin, Y.; Ally, N.; Post, B.K.The promise of additive manufacturing is that a user can design and print complex geometries that are very difficult, if not impossible, to machine. The capabilities of 3D printing are restricted by a number of factors, including properties of the build material, time constraints, and geometric design restrictions. In this paper, a thorough accounting and study of the geometric restrictions that exist in the current iteration of additive manufacturing (AM) fused deposition modeling (FDM) technologies on a large scale are discussed. Offline and online methodologies for collecting data sets for qualitative analysis of large scale AM, in particular Oak Ridge National Laboratory’s (ORNL) big area additive manufacturing (BAAM) system, are summarized. In doing so, a survey of tools for designers and software developers is provided. In particular, strategies in which geometric data can be used as training sets for smarter AM technologies in the future are explained.Item Benchmarking Evaluation of an Open Source Fused Deposition Modeling Additive Manufacturing System(University of Texas at Austin, 2011) Johnson, W.M.; Rowell, M.; Deason, B.; Eubanks, M.The availability of more affordable open source Additive Manufacturing (AM) systems has lead to the increased awareness and use of AM technologies. However, further expansion will necessitate improved reliability and an increased understanding in the limitations of these systems. This paper will review previous benchmarking models, and present the development of a new benchmarking model and its application in the evaluation of an open source AM system based on fused deposition modeling (FDM). The proposed benchmarking model includes various geometric features to evaluate the AM system in terms of dimensional accuracy, thermal warpage, staircase effect, and geometric and dimensional tolerances.Item Capillary-Driven Flow in Open Microchannels Printed with Fused Deposition Modeling(University of Texas at Austin, 2015) Lade, Robert K. Jr; Hippchen, Erik J.; Rodgers, Luke; Macosko, Christopher; Francis, Lorraine F.The fundamentals of fluid flow in 3D printed, open microchannels created using fused deposition modeling (FDM) are explored. Printed microchannels are used in microfluidic devices and have potential applications in embedding electronics in plastic substrates. However, FDM parts possess rough surfaces, and in this study, surface topography is shown to have an important impact on flow behavior, causing the liquid to travel down the channel with a characteristic ‘pulsing’ movement. We also analyze the influence of print orientation on capillary flow, where microchannels printed in specific orientations are shown to exhibit different flow dynamics.Item Cleated Print Surface for Fused Deposition Modeling(University of Texas at Austin, 2016) Shafer, C.S.; Siddel, D.H.; Merriman, A.L.; Elliott, A.M.Fused Deposition Modeling (FDM) has become popular among Additive Manufacturing technologies due to its low cost, speed, and geometric scalability; however, the primitive nature of the FDM build surface fundamentally limits the utility of FDM in terms of reliability, autonomy, and material selection. Currently, FDM relies on adhesive forces between the first layer of a print and the build surface; depending on the materials involved, this adhesive bond may or may not be reliable. Thermal contraction between the build plate and build materials can break that bond, which causes warpage and delamination of the part from the build surface and subsequent failure of the part. Furthermore, with each print, the user must use tools or special maneuvering to separate the printed part from the build surface as well as retexture or replace the used build surface. In this paper we present a novel build platform that allows for a mechanical bond between the print and build surface by using dovetail-shaped features. The first layer of the print flows into the features and becomes mechanically captivated by the build platform. Once the print is completed, the platform is rolled or flexed open to release the part from the mechanical bond. This design not only lowers the risk of delamination during printing but also eliminates the need for a user to reset or replace the build surface between print jobs. The effectiveness of each geometry was determined by measuring the distance at the pinch point compared to the distance that the extrusion filled below the pinch point. The Captivation Ratio was measured to compare the different geometries tested and determine which direction of extrusion creates a better ratio.Item Comparison of Component Properties and Economic Efficiency of the Arburg Plastic Freeforming and Fused Deposition Modeling(University of Texas at Austin, 2021) Hecker, F.; Driediger, C.; Hirsch, A.; Moritzer, E.The additive manufacturing process Fused Deposition Modeling (FDM) is established in the industry for many years. A new, similar process to FDM is the Arburg Plastic Freeforming (APF). The main differences between both processes are the form of the starting material (FDM: Filaments, APF: Conventional granulate) and the material deposition during the layer formation (FDM: Melt strand, APF: fine molten droplets). Since the two processes can be used in similar applications, the aim of this study is to compare both processes in a holistic way. Furthermore, the advantages and disadvantages of the processes are to be highlighted. The systematic comparison between a Stratasys 400mc and the Freeformer 200-3X is divided into the areas of component properties, design limitations and economic efficiency. The material ABS-M30 (Stratasys) is used in both processes. The results show comparable component properties regarding mechanical and optical properties but also differences in design limitations and cost efficiency.Item A Comparison of Modeling Methods for Predicting the Elastic-Plastic Response of Additively Manufactured Honeycomb Structures(University of Texas at Austin, 2018) Sharma, Raghav; Le, Thao; Song, Jiaxu; Harms, Ethaniel; Sowa, Daniel; Grishin, Alex; Bhate, DhruvValid and accurate models describing the mechanical behavior of additively manufactured cellular materials are crucial to enabling their implementation in critical-to-function parts. Broadly speaking, the modeling approaches commonly used in the literature fall into three categories. Each of these differs in the level of discretization at which the cellular behavior is modeled: at the level of each material point, at the level of the unit cell or at the level of a connecting member that constitutes a unit cell. Each of these three approaches relies on different characterization techniques and the way in which the resulting data is leveraged in the development of the model. In this work, we critically examine all three modeling approaches using FEA and compare their accuracy in the prediction of the elastic and plastic behavior of experimentally characterized hexagonal honeycomb structures made with Fused Deposition Modeling, and discuss the pros and cons of each method.Item Compressive Response of Strut-Reinforced Kagome with Polyurethane Reinforcement(University of Texas at Austin, 2019) Gautam, Rinoj; Sridharan, Vijay Shankar; Teh, Wee Lee; Idapalapati, SridharLattice structures find immense application in lightweight structures for their high specific strength, modulus, and energy absorption. Strut-reinforced Kagome (SRK) structures provide better compressive performance compared to many existing lattice structures. In this study, the performance of acrylonitrile butadiene styrene (ABS) SRK lattice structures, fabricated by fused deposition modeling, under compression loading is investigated. Further, SRK structures were filled with different polyurethane in the empty space and their effect on the compressive performance was examined. The SRK structure demonstrated abrupt failure at the joints in the vicinity of face sheet, thereby reducing the energy absorption of the structure. The SRK with flexible foam (low-density polyurethane foam) had no significant effect on peak failure load and moduli, whereas energy absorption per unit mass was higher by 16.5%. The SRK with the rigid foam (high-density foam) displayed not only the better energy absorption per unit mass (116%) but also different failure behavior than SRK only.Item Considering Machine- and Process-Specific Influences to Create Custom-Built Specimens for the Fused Deposition Modeling Process(University of Texas at Austin, 2017) Schumacher, Christian; Schöppner, Volker; Guntermann, JonasCompared to conventional polymer processing technologies the material selection in the Fused Deposition Modelling (FDM) process is restricted. To expand the range of materials the requirements for the material properties and the semi-finished products (filaments) must be clarified. For this, a machine- and process-independent rating of the processability is necessary. The established standards for the tensile strength test apply to specimens with nearly isotropic mechanical properties. The FDM process generates anisotropic parts. The properties are mainly influenced by the machine quality and the data processing. It is not possible to test a material for FDM independently of the machine and the data processing. In this paper, machine and process-specific influences are investigated. Considering these influences, a custom-built specimen is created to test the tensile strength of the welding seams for polyamide 6. This procedure allows a machine- and process-independent rating of the processability in terms of tensile strength for different materials.Item Design for Additive Manufacturing of Kinematic Pairs(University of Texas at Austin, 2014) Pareek, Shrey; Sharma, Vaibhav; Rai, RahulWhile additive manufacturing processes are better suited for fabrication of parts with complex geometries, they face serious challenges whilst fabricating parts that require relative motion with respect to each other. The primary challenge in additive manufacturing of mechanisms is preventing the mating parts from bonding with each other during the fabrication process. In this paper the authors investigate design and additive fabrication of kinematic pairs that can move relative to each other. The paper outlines fabrication of kinematic pairs based on optimal clearance value for three basic lower order kinematic pairs, viz. revolute pair, prismatic pair, and cylindrical pair. Using empirical testing functional relationships between extractive force and clearance, and between moment and clearance have been developed. These functional relationships can be used by users to fabricate kinematic pairs using FDM based 3D printing processes. The efficacy of the proposed approach is demonstrated on 3D printed kinematic pairs and experimental validation studies.Item Design of Passive Dynamic Walking Robots for Additive Manufacture(University of Texas at Austin, 2015) Modica, F.; Stöckli, F.R.; Shea, K.Ongoing research in the direction of printable, non-assembly mechatronic systems give rise to the need for multi-material printing, including electronics. However, there are robotic systems that do not use electronic components and still exhibit complex dynamic behavior. Such passive dynamic systems have the potential to save energy and component cost in the field of robotics compared to actuated systems. Ongoing research in computational design synthesis of passive dynamic systems aims at automatically generating robotic configurations based on a given task. However, an automated design-to-fabrication process also requires a flexible fabrication method. Towards the goal of printing functional, non-assembly passive dynamic robots using Fused Deposition Modeling (FDM), this paper explores designing and fabricating passive walking robots and all necessary components using single material FDM. Two configurations of passive dynamic walkers are re-designed and fabricated in this paper. For one of them all components are printed in one job and only little assembly after printing is needed. However, the gait cycle of the second configuration is much more sensitive to small parametric changes and therefore more flexible prototyping is needed in order to allow adjusting of the robot after printing. Moreover, FDM printed robotic joints with sufficient smoothness and axial stiffness are required and a variety of different joint assemblies are designed and tested for the robot prototypes. Even though the most stable gait for the second robot is achieved using a metal bearing instead of the FDM printed ones, this is not necessary for the first robot example. The approach to prototyping with FDM presented in this paper allows achieving functionality through design iteration without incurring significant cost. To arrive at feasible solutions, a modular design approach allows to combine different joints, legs, feet and balancing weights and the connection points of the different elements are adjustable after printing, which makes it possible to shift the center of gravity and other variables of the robot.Item DETERMINATION AND COMPENSATION OF THE SHRINKAGE BEHAVIOR OF CYLINDRICAL ELEMENTS IN THE FDM PROCESS(University of Texas at Austin, 2023) Koers, T.; Magyar, B.Fused Deposition Modeling (FDM) is an additive manufacturing process to produce complex thermoplastic geometries layer by layer. The filament is melted in a nozzle, iteratively deposited, and then cools down. Due to the solidification process, the deposited filament strands deviate from their intended position due to shrinkage, resulting in significant geometric deviations in the final part. In terms of dimensional accuracy, there is a need for optimization, especially for local curved geometries in relation to the global part with higher nominal dimensions. The aim of this study is to investigate the size and shape deviations for cylindrical FDM elements and to compensate the expected deformations by using an in-house software with adaptive scaling factors in the x-y plane. Previous studies mainly focus on simple, non-curved objects, this study also considers the influence of curvature and global as well as local deviations on the final part.Item Development of a Low-Cost Parallel Kinematic Machine for Multi-Directional Additive Manufacturing(University of Texas at Austin, 2013) Song, Xuan; Pan, Yayue; Chen, YongMost additive manufacturing (AM) processes are layer-based with three linear motions in the X, Y and Z axes. However, there are drawbacks associated with such limited motions, e.g. non-conformal material properties, stair-stepping effect, and limitations on building-around-inserts. Such drawbacks will limit additive manufacturing to be used in more general applications. To enable 6-axis motions between a tool and a work piece, we investigate a Stewart mechanism and developed a low-cost prototype system for multi-directional additive manufacturing processes such as the Fused Deposition Modeling (FDM) and CNC Accumulation. The technical challenges in developing such an AM system are discussed including the hardware design, motion planning and modeling, platform constraint checking, tool motion simulation, and platform calibration. Several test cases are performed to illustrate the capability of the developed multi-directional additive manufacturing system.Item Discrete Element Modeling of Fused Deposition Modeling Process(University of Texas at Austin, 2021) Menezes, C.; Turner, C.Fused Deposition Modeling components show anisotropic material properties as a result of the difference in bonding strengths between inter- and intra-layer particles. This difference occurs due to temperature gradient of the deposited filaments which affects the filament adhesion as well as due to the presence of voids or other discontinuities in the printed object. Discrete Element Modelling (DEM) is a discontinuous methodology which follows the idea of treating filaments as discrete rigid particles with simplified geometries for calculating the thermal interactions between the particles. Models using this approach allow the investigators to correlate the adhesion effects between filaments based on experimental data which ultimately will allow for optimization of the relevant printing parameters.Item The Economics of Big Area Additive Manufacturing(University of Texas at Austin, 2016) Post, B.K.; Lind, R.F.; Lloyd, P.D.; Kunc, V.; Linhal, J.M.; Love, L.J.Case studies on the economics of Additive Manufacturing (AM) suggest that processing time is the dominant cost in manufacturing. Most additive processes have similar performance metrics: small part sizes, low production rates and expensive feedstocks. Big Area Additive Manufacturing is based on transitioning polymer extrusion technology from a wire to a pellet feedstock. Utilizing pellets significantly increases deposition speed and lowers material cost by utilizing low cost injection molding feedstock. The use of carbon fiber reinforced polymers eliminates the need for a heated chamber, significantly reducing machine power requirements and size constraints. We hypothesize that the increase in productivity coupled with decrease in feedstock and energy costs will enable AM to become more competitive with conventional manufacturing processes for many applications. As a test case, we compare the cost of using traditional fused deposition modeling (FDM) with BAAM for additively manufacturing composite tooling.Item The Effect of Cell Size and Surface Roughness on the Compressive Properties of ABS Lattice Structures Fabricated by Fused Deposition Modeling(University of Texas at Austin, 2019) Mason, L.; Leu, M.C.Researchers looking to improve the surface roughness of acrylonitrile butadiene styrene (ABS) parts fabricated by fused deposition modeling (FDM) have determined that acetone smoothing not only achieves improved surface roughness but increases compressive strength as well. However, the sensitivity of ABS parts to acetone smoothing has not been explored. In this study we investigated FDM-fabricated ABS lattice structures of various cell sizes subjected to cold acetone vapor smoothing to determine the combined effect of cell size and acetone smoothing on the compressive properties of the lattice structures. The acetone-smoothed specimens performed better than the as-built specimens in both compression modulus and maximum load, and there was a decrease in those compressive properties with decreasing cell size. The difference between as-built and acetone-smoothed specimens was found to increase with decreasing cell size for the maximum load.Item Effect of Porosity on Electrical Insulation and Heat Dissipation of Fused Deposition Modeling Parts Containing Embedded Wires(University of Texas at Austin, 2018) Billah, Kazi Md Masum; Coronel, Jose Luis Jr; Wicker, Ryan B.; Espalin, DavidWhile the effects of porosity on the mechanical strength of fused deposition modeling (FDM) parts have been thoroughly investigated, there exists a need for evaluating electrical and thermal properties. This work describes the method of determining the effect of porosity that resembles 3D printed electronics. In addition to mechanical strength, determination of desirable limit of electrical insulation and heat dissipation will allow the additive manufacturing community to fabricate power electronics components with reduced cost and improved performance. For experimentation, three different sets of coupons were fabricated using Polycarbonate (PC) thermoplastic with embedded bare copper wire. Characterization included high electrical stresses and thermal testing to determine the effect of porosity on insulation and heat dissipation, respectively. During electrical characterization, higher wire density resulted in reduced breakdown strength. In thermal test, the comparisons between as fabricated and heat-treated specimen showed that heat dissipation increased by an average of 30 % to 40 %.Item Effect of Sparse-Build Internal Structure on Performance of Fused Deposition Modeling Tools Under Pressure(University of Texas at Austin, 2016) Meng, S.; Mason, L.; Taylor, G.; Wang, X.; Leu, M.C.; Chandrashekhara, K.Two different approaches to design a sparse-build tool for fabrication by the fused deposition modeling (FDM) process are compared. One approach uses a 2D lattice structure and the other approach is inspired by topology optimization. Ultem 9085 is used as the material, and the amount of material used to build the tool is kept constant to ensure a fair comparison. A solid tool is also included in the comparison. The performance of the tool under uniform pressure is simulated using finite element analysis (FEA) and the accuracy of the FEA results is verified by comparing them with experimentally measured data for a similar tool. The build material, support material, build time, maximum displacement, and maximum von Mises stress are compared for the three build approaches, with an emphasis on the pros and cons of each sparse-build tool with regards to performance under uniform pressure and fabrication by FDM.
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