scholarly journals An Architecture for Hybrid Manufacturing Combining 3D Printing and CNC Machining

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Marcel Müller ◽  
Elmar Wings

Additive manufacturing is one of the key technologies of the 21st century. Additive manufacturing processes are often combined with subtractive manufacturing processes to create hybrid manufacturing because it is useful for manufacturing complex parts, for example, 3D printed sensor systems. Currently, several CNC machines are required for hybrid manufacturing: one machine is required for additive manufacturing and one is required for subtractive manufacturing. Disadvantages of conventional hybrid manufacturing methods are presented. Hybrid manufacturing with one CNC machine offers many advantages. It enables manufacturing of parts with higher accuracy, less production time, and lower costs. Using the example of fused layer modeling (FLM), we present a general approach for the integration of additive manufacturing processes into a numerical control for machine tools. The resulting CNC architecture is presented and its functionality is demonstrated. Its application is beyond the scope of this paper.

Author(s):  
Haris Ali Khan ◽  
Toyosi Ademujimi

Abstract This study unearths a novel approach utilizing conventional subtractive manufacturing technology (5-axis CNC milling center) to realize additively manufactured complex geometries without employing support structures. The proposed approach was based on benefiting from the precision and accuracy of subtractive manufacturing while leveraging the freedom of design of additive manufacturing (AM) process. The desired objectives were achieved in a three-stepped methodology where initially the CNC machine was modified to adapt the 3D printing protocols while in the second step, additional hardware was retrofitted on the conventional CNC machine making it compatible to print 3D parts. A “geometric subsection” approach was adopted as the third step where the desired printed part was divided in different subsections based on the overhang angles and the rotational axes of the CNC machine was then utilized in a manner to eliminate the need for support structures. The manufactured AM part can then be post-processed employing the same machining platform. The proposed approach thereby also served as a next step in evolution of done-in-one processes by printing near-net shape components through additive manufacturing and then promptly acquiring the net shape through subtractive manufacturing techniques.


2018 ◽  
Vol 18 (4) ◽  
pp. 5-24 ◽  
Author(s):  
Wit GRZESIK

This review paper highlights the hybrid manufacturing processes which integrate the additive and subtractive processes performing on one hybrid platform consisting of the LMD (laser metal deposition) unit and CNC machine tools. In particular, some important rules and advantages as well as technological potentials of the integration of different AM technique and finishing CNC machining operations are discussed and overviewed. Some representative examples such as formation of difficult features around the part periphery, deposition of functional layers and coatings and repair of high-value parts in aerospace industry are provided. Some conclusions and future trends in the implementation of hybrid processes are outlined.


2021 ◽  
Vol 111 (06) ◽  
pp. 363-367
Author(s):  
Lukas Langer ◽  
Matthias Schmitt ◽  
Georg Schlick ◽  
Johannes Schilp

Die additive Fertigung ermöglicht komplexe Geometrien und individualisierte Bauteile. Die hohen Material- und Fertigungskosten können ein Hindernis für einen wirtschaftlichen Einsatz sein. In der hybriden additiven Fertigung werden die Vorteile konventioneller sowie additiver Fertigungsverfahren kombiniert. Für eine weitere Steigerung der Wirtschaftlichkeit und Effizienz werden nichtwertschöpfende Schritte der Prozesskette identifiziert und Automatisierungsansätze entwickelt.   Additive manufacturing enables complex geometries and individualized components. However, high material and manufacturing costs can be a hindrance for economical use. Hybrid additive manufacturing combines the advantages of conventional with additive manufacturing processes. For a further increase in profitability and efficiency, non-value-adding steps in the process chain are identified and automation approaches developed.


2019 ◽  
Vol 31 (1) ◽  
pp. 124-144 ◽  
Author(s):  
Danielle Strong ◽  
Michael Kay ◽  
Thomas Wakefield ◽  
Issariya Sirichakwal ◽  
Brett Conner ◽  
...  

Purpose Although the adoption of metal additive manufacturing (AM) for production has continuously grown, in-house access to production grade metal AM systems for small and medium enterprises (SMEs) is a major challenge due to costs of acquiring metal AM systems, specifically powder bed fusion AM. On the other hand, AM technology in directed energy deposition (DED) has been evolving in both: processing capabilities and adaptable configuration for integration within existing traditional machines that are available in most SME manufacturing facilities, e.g. computer numerical control (CNC) machining centers. Integrating DED with conventional processes such as machining and grinding into Hybrid AM is well suited for remanufacturing of metal parts. The paper aims to discuss these issues. Design/methodology/approach Classical facility location models are employed to understand the effects of SMEs adopting DED systems to offer remanufacturing services. This study identifies strategically located counties in the USA to advance hybrid AM for reverse logistics using North American Industry Classification System (NAICS) data on geographical data, demand, fixed and transportation costs. A case study is also implemented to explore its implications on remanufacturing of high-value parts on the reverse logistics supply chain using an aerospace part and NAICS data on aircraft maintenance, repair and overhaul facilities. Findings The results identify the candidate counties, their allocations, allocated demand and total costs. Offering AM remanufacturing services to traditional manufacturers decreases costs for SMEs in the supply chain by minimizing expensive new part replacement. The hubs also benefit from hybrid AM to repair their own parts and tools. Originality/value This research provides a unique analysis on reverse logistics through hybrid AM focused on remanufacturing rather than manufacturing. Facility location using real data is used to obtain results and offers insights into integrating AM for often overlooked aspect of remanufacturing. The study shows that SMEs can participate in the evolving AM economy through remanufacturing services using significantly lower investment costs.


Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 457 ◽  
Author(s):  
Philipp Sauerbier ◽  
James Anderson ◽  
Douglas Gardner

Recent advances in large-scale thermoplastic additive manufacturing (AM), using fused deposition modelling (FDM), have shown that the technology can effectively produce large aerospace tools with common feed stocks, costing 2.3 $/kg, such as a 20% carbon-filled acrylonitrile butadiene styrene (ABS). Large-scale additive manufacturing machines have build-volumes in the range of cubic meters and use commercially available pellet feedstock thermoplastics, which are significantly cheaper (5–10 $/kg) than the filament feedstocks for desktop 3D printers (20–50 $/kg). Additionally, large-scale AM machines have a higher material throughput on the order of 50 kg/h. This enables the cost-efficient tool production for several industries. Large-scale 3D-printed tooling will be computerized numerical control (CNC)-machined and -coated, to provide a surface suitable for demolding the composite parts. This paper outlines research undertaken to review and improve the adhesion of the coating systems to large, low-cost AM composite tooling, for marine or infrastructure composite applications. Lower cost tooling systems typically have a lower dimensional accuracy and thermal operating requirements than might be required for aerospace tooling. As such, they can use lower cost commodity grade thermoplastics. The polymer systems explored in the study included polypropylene (PP), styrene-maleic anhydride (SMA), and polylactic acid (PLA). Bio-based filler materials were used to reduce cost and increase the strength and stiffness of the material. Fillers used in the study included wood flour, at 30% by weight and spray-dried cellulose nano-fibrils, at 20% by weight. Applicable adhesion of the coating was achieved with PP, after surface treatment, and untreated SMA and PLA showed desirable coating adhesion results. PLA wood-filled composites offered the best properties for the desired application and, furthermore, they have environment-friendly advantages.


Author(s):  
Nathan Decker ◽  
Qiang Huang

Abstract While additive manufacturing has seen tremendous growth in recent years, a number of challenges remain, including the presence of substantial geometric differences between a three dimensional (3D) printed part, and the shape that was intended. There are a number of approaches for addressing this issue, including statistical models that seek to account for errors caused by the geometry of the object being printed. Currently, these models are largely unable to account for errors generated in freeform 3D shapes. This paper proposes a new approach using machine learning with a set of predictors based on the geometric properties of the triangular mesh file used for printing. A direct advantage of this method is the simplicity with which it can describe important properties of a 3D shape and allow for predictive modeling of dimensional inaccuracies for complex parts. To evaluate the efficacy of this approach, a sample dataset of 3D printed objects and their corresponding deviations was generated. This dataset was used to train a random forest machine learning model and generate predictions of deviation for a new object. These predicted deviations were found to compare favorably to the actual deviations, demonstrating the potential of this approach for applications in error prediction and compensation.


Author(s):  
Christiane Beyer ◽  
Dustin Figueroa

Additive manufacturing (AM) enables time and cost savings in the product development process. It has great potential in the manufacturing of lighter parts or tools by the embedding of cellular/lattice structures that consume less material while still distributing the necessary strength. Less weight and less material consumption can lead to enormous energy and cost savings. Although AM has come a long way over the past 25–30 years since the first technology was invented, the design of parts and tools that capitalize on the technology do not yet encompass its full potential. Designing for AM requires departing from traditional design guidelines and adopting new design considerations and thought structures. Where previous manufacturing techniques (computer numerical control (CNC) machining, casting, etc.) often necessitated solid parts, AM allows for complex parts with cellular and lattice structure implementation. The lattice structure geometry can be manipulated to deliver the level of performance required of the part. The development and research of different cell and lattice structures for lightweight design is of significant interest for realizing the full potential of AM technologies. The research not only includes analysis of existing software tools to design and optimize cell structures, but it also involves design consideration of different unit cell structures. This paper gives a solid foundation of an experimental analysis of additive manufactured parts with diverse unit cell structures in compression and flexural tests. Although the research also includes theoretical finite element analysis (FEA) of the models, the results are not considered here. As an introduction, the paper briefly explains the basics of stress and strain relationship and summarizes the test procedure and methods. The tests concentrate primarily on the analysis of 3D printed polymer parts manufactured using PolyJet technology. The results show the behavior of test specimens with different cell structures under compression and bending load. However, the research has been extended and is still ongoing with an analysis of selective laser melted test specimens in aluminum alloy AlSi10Mg.


2020 ◽  
Vol 6 (2) ◽  
pp. 029-033
Author(s):  
Herick Henci Agrisa

This paper discusses the pre and process of running a computer numerical control machine (CNC) using computer-aided design (CAD) software commonly used to design products to be produced and computer-aided manufacture (CAM) software used to control machines during the manufacturing process. Some types of CNC machines in general, namely CNC lathe machine and CNC milling machine. The history of the development of the CNC Machine was begun in 1952 by John Pearseon of the Massachusetts Institute of Technology on behalf of the United States Air Force, which aims to make complicated special workpieces. In addition, this paper also discusses the basic numerical code types used in CNC machines.


Author(s):  
Marwan Khalid ◽  
Qingjin Peng

Abstract Additive Manufacturing (AM) offers many advantages to make objects compared to traditional subtractive manufacturing, for example, complex geometries can be easily fabricated, and light weight parts can be formed while maintaining the parts strength for the low carbon footprint, low material consumption and waste. But there are areas for AM to improve in sustainability, reliability, productivity, robustness, material diversity and part quality. Life cycle assessment (LCA) studies have identified that the AM printing stage has a big impact on the life cycle sustainability (LCS) of 3D printed products. AM building parameters can be properly selected to control the LCS. This research explores the optimal AM process parameters to reduce the process energy and material consumption. Investigated parameters include the printing layer height, number of shells, material infilling percentage, infilling type and building orientation. Design of experiments (DOE) approach and statistical analysis tools are used to find optimal parameter settings for sustainable AM. Models formulated in this research can be easily extended to other additive manufacturing processes.


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