Offset Slices for Layered Manufacturing

2002 ◽  
Author(s):  
Prabhjot Singh ◽  
Debasish Dutta
Keyword(s):  
Layered Manufacturing ◽  
Thin Layers ◽  
Post Processing ◽  
Build Time ◽  
Solution Methodology ◽  
Dimensional Domain ◽  
Task Framework

Layered Manufacturing (LM) techniques build a part by adding thin layers of material. In this process overhangs need to be supported by sacrificial supports, resulting in an increase in the build time, wastage of material and requiring costly post-processing. Metal based LM machines with the capability to deposit material along multiple directions resolve most of the above problems. These machines have the capability to deposit non-planar slices. In this paper we study such slices and present a task framework for their use with multi-directional LM machines. A solution methodology is presented for the 2 dimensional domain which can be extended to 3 dimensions.

Offset Slices for Multidirection Layered Deposition

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Prabhjot Singh ◽  
Debasish Dutta
Keyword(s):  
Layered Manufacturing ◽  
Thin Layers ◽  
Post Processing ◽  
Build Time ◽  
Overhang Angle ◽  
Task Framework

Layered Manufacturing (LM) techniques build a part by adding thin layers of material. In this process, overhangs need to be supported by sacrificial supports, resulting in an increase in the build time, wastage of material, and costly post-processing. Metal-based LM machines with the capability to deposit material along multiple directions resolve most of the above problems. Importantly, these machines can deposit nonplanar slices. In this paper, we study such slices and present a task framework for their use with multidirectional layered deposition machines. The aim of the analysis is to identify part subvolumes that can be built using nonplanar slices for a process-dependent overhang angle. Solution methodologies for 2D, extruded parts, and general 3D parts are presented. Algorithms and illustrative example parts are included.

Multi-Direction Slicing for Layered Manufacturing

2001 ◽  
Vol 1 (2) ◽  
pp. 129-142 ◽  
Author(s):  
Prabhjot Singh ◽  
Debasish Dutta
Keyword(s):  
Surface Quality ◽  
Layered Manufacturing ◽  
Support Structure ◽  
Surface Accuracy ◽  
Build Time ◽  
Key Issues ◽  
Limited Surface ◽  
Task Framework

Parts made by Layered Manufacturing (LM) have a limited surface accuracy and their build time is often long due to the deposition of sacrificial support structure. However, LM machines with an ability to deposit along multiple directions can improve upon the surface quality and reduce the support volume. In this paper we analyze the problem of multi-direction slicing. This analysis addresses the questions: How much of a part should be made along a particular direction and why. The strategy used in multi-direction slicing is to progressively decompose the part into sub-volumes, each of which can be completely built along a certain direction. Key issues are identified and a task framework for multidirection slicing is proposed. Algorithms and implemented examples are presented.

Composition and Microstructure of Laser Cladding of 316 Stainless Steel

2011 ◽  
Vol 467-469 ◽  
pp. 2054-2059
Author(s):  
Kai Zhang ◽  
Miao Yan Li ◽  
Xin Min Zhang
Keyword(s):  
Stainless Steel ◽  
Laser Cladding ◽  
Layered Manufacturing ◽  
Rapid Manufacturing ◽  
Cad Model ◽  
Laser Metal Deposition ◽  
Post Processing ◽  
316 Stainless Steel ◽  
3D Cad ◽  
Manufacturing Techniques

Laser Metal Deposition Shaping (LMDS) is a Rapid Manufacturing (RM) process that can be classified under the area of layered manufacturing techniques, where parts are built in layers. Parts of any complexity can be built directly from the 3D CAD model without much human intervention and requires minimum post-processing. In fact, LMDS technique can be recognized as multilayer laser cladding. Accordingly, it is necessary to perform the elementary laser cladding experiments with common metal powder so as to better understand the LMDS process. Then the characteristics of microstructure, composition and phase of as-deposited clads were analyzed through SEM and XRD, as well as relative model. The results prove that the microstructure of 316 stainless steel deposits is composed of the slender dendrites growing epitaxially from the substrate, and the composition is uniform without obvious segregation. Besides, it can be deduced from XRD diagram that the microstructure is composed of mono-phase γ.

scholarly journals Design and Validation of Integrated Clamping Interfaces for Post-Processing and Robotic Handling in Additive Manufacturing

2021 ◽  
Author(s):  
Julian Ferchow ◽  
Dominik Kälin ◽  
Gokula Englberger ◽  
Marcel Schlüssel ◽  
Christoph Klahn ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Machining Process ◽  
Post Processing ◽  
Maximum Displacement ◽  
Build Time ◽  
Clean Interface ◽  
Tool Accessibility ◽  
Form Deviation ◽  
Metallic Parts ◽  
Subtractive Machining

Abstract Additive manufacturing (AM), particularly laser-based powder bed fusion of metals (LPBF), enables the fabrication of complex and customized metallic parts. However, 20–40% of the total manufacturing costs are usually attributed to post-processing steps. To reduce the costs of extensive post-processing, the process chain for AM parts has to be automated. Accordingly, robotic gripping and handling processes, as well as an efficient clamping for subtractive machining of AM parts, are key challenges. This study introduces and validates integrated bolts acting as a handling and clamping interface of AM parts. The bolts are integrated into the part design and manufactured in the same LPBF process. The bolts can be easily removed after the machining process using a wrench. This feasibility study investigates different bolt elements. The experiments and simulations conducted in the study show that a force of 250 N resulted in a maximum displacement of 12.5 µm. The milling results of the LPBF parts reveal a maximum roughness value, Ra, of 1.42 µm, which is comparable to that of a standard clamping system. After the bolt removal, a maximum residual height of 0.067 mm remains. Two case studies are conducted to analyze the form deviation, the effect of bolts on build time and material volume and to demonstrate the application of the bolts. Thus, the major contribution of this study is the design and the validation of standardized interfaces for robotic handling and clamping of complex AM parts. The novelties are a simple and clean interface removal, less material consumption, less support structure required and finally an achievement of a five-side tool accessibility by combining the interfaces with a three-jaw chuck.

Some Geometric Techniques to Reduce Build Time in LOM

2001 ◽  
Author(s):  
Pang King Wah ◽  
Ajay Joneja
Keyword(s):  
Layered Manufacturing ◽  
Manufacturing Technology ◽  
Rectangular Grid ◽  
Geometric Properties ◽  
Traditional Technique ◽  
Laminated Object Manufacturing ◽  
Build Time ◽  
Waste Removal ◽  
Geometric Techniques

Abstract We propose a new CAPP system for the layered manufacturing technology of LOM (laminated object manufacturing). The traditional technique of building wastes much effort and time in generation of rectangular grid patterns to the exterior of the model to facilitate waste removal. In the proposed approach, several geometric properties of the model are exploited to dramatically reduce the waste removal grids. This in turn leads to reduced build-time, with no effect on the build quality. An integrated CAPP system incorporating these ideas has been developed, and an example part is presented to show how the system performs.

Multi-Direction Slicing for Layered Manufacturing

2000 ◽  
Author(s):  
Prabhjot Singh ◽  
Debasish Dutta
Keyword(s):  
Surface Quality ◽  
Layered Manufacturing ◽  
Support Structure ◽  
Surface Accuracy ◽  
Build Time ◽  
Limited Surface

Abstract Parts made by Layered Manufacturing (LM) have a limited surface accuracy and their build time is often long due to the deposition of sacrificial support structure. However, LM machines with an ability to deposit along multiple directions can improve upon the surface quality and reduce the support volume. In this paper we consider multi-directional slicing, present algorithms and implemented examples.

Tolerance-Based Layer Setup Optimization for Layered Manufacturing

2010 ◽  
Author(s):  
Jack Szu-Shen Chen ◽  
Hsi-Yung Steve Feng
Keyword(s):  
Layer Thickness ◽  
Maximum Error ◽  
Layered Manufacturing ◽  
Design Model ◽  
Maximum Efficiency ◽  
Original Design ◽  
Allowable Deviation ◽  
Number Of Layers ◽  
Build Time ◽  
Model Geometry

This paper introduces a new tolerance-based method to generate the optimum layer setup required to build layered manufacturing (LM) end-user parts for maximized efficiency. To achieve this, the deviation between the final polished LM part geometry and the original design model are formulated and controlled. Maximized layer thicknesses are then realized through optimization of each layer position with respect to the design and final geometry and maximization of the allowable deviation for each layer, which consequently leads to minimization of the build time. Current LM layer setup methods do not take into account of the final part during layer setup generation, rendering layer thickness selection to operator-deemed-best. Without the ability to predict the final geometry and to optimize the layer setup accordingly, layer thickness selection is often overly conservative, causing more layers than necessary to be used. Since the LM build time increases exponentially with an increase in the number of layers, efficiency is greatly reduced with conservative layer setup. To achieve maximum efficiency, this paper proposes a new method based on error compensation and minimization to solve for the optimum layer setup necessary to allow the resulting final physical part to reliably approximate the design model geometry according to a user specified tolerance limit. Case studies have been performed in order to validate that the proposed method is able to minimize the number of layers for constructing an LM part while controlling the maximum error for tolerance conformance.

Pre-Processing of Heterogeneous Objects for Layered Manufacturing

2001 ◽  
Author(s):  
Ki-Hoon Shin ◽  
Debasish Dutta
Keyword(s):  
Tool Path ◽  
New Technology ◽  
Three Dimensional ◽  
Layered Manufacturing ◽  
Pattern Generation ◽  
Geometric Features ◽  
Adaptive Slicing ◽  
Heterogeneous Objects ◽  
Build Time ◽  
Material Information

Abstract Layered manufacturing (LM) is emerging as a new technology that enables fabrication of three dimensional heterogeneous objects (such as Multi-materials and Functionally Gradient Materials). The steps for fabricating heterogeneous objects include model representation and material process planning. This paper introduces a method for processing the material information. It includes pre-processing (discretization), orientation (build direction selection), and adaptive slicing of heterogeneous objects. The discretization process converts all material information inside a heterogeneous object to material features like geometric features, thus it makes it possible to determine build direction by estimating build time based on geometric features and material features. It also allows adaptive slicing of heterogeneous objects to minimize surface finish and material resolution error. In addition, tool path planning can be simplified to fill pattern generation. Examples are shown.

scholarly journals Design and validation of integrated clamping interfaces for post-processing and robotic handling in additive manufacturing

2021 ◽  
Author(s):  
Julian Ferchow ◽  
Dominik Kälin ◽  
Gokula Englberger ◽  
Marcel Schlüssel ◽  
Christoph Klahn ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Machining Process ◽  
Post Processing ◽  
Maximum Displacement ◽  
Build Time ◽  
Clean Interface ◽  
Tool Accessibility ◽  
Form Deviation ◽  
Metallic Parts ◽  
Subtractive Machining

AbstractAdditive manufacturing (AM), particularly laser-based powder bed fusion of metals (LPBF), enables the fabrication of complex and customized metallic parts. However, 20–40% of the total manufacturing costs are usually attributed to post-processing steps. To reduce the costs of extensive post-processing, the process chain for AM parts has to be automated. Accordingly, robotic gripping and handling processes, as well as an efficient clamping for subtractive machining of AM parts, are key challenges. This study introduces and validates integrated bolts acting as a handling and clamping interface of AM parts. The bolts are integrated into the part design and manufactured in the same LPBF process. The bolts can be easily removed after the machining process using a wrench. This feasibility study investigates different bolt elements. The experiments and simulations conducted in the study show that a force of 250 N resulted in a maximum displacement of 12.5 µm. The milling results of the LPBF parts reveal a maximum roughness value, Ra, of 1.42 µm, which is comparable to that of a standard clamping system. After the bolt removal, a maximum residual height of 0.067 mm remains. Two case studies are conducted to analyze the form deviation, the effect of bolts on build time, and material volume and to demonstrate the application of the bolts. Thus, the major contribution of this study is the design and the validation of standardized interfaces for robotic handling and clamping of complex AM parts. The novelties are a simple and clean interface removal, less material consumption, less support structure required, and finally an achievement of a five-side tool accessibility by combining the interfaces with a three-jaw chuck.

Fluid Mechanics of Slot Coating in Layered Manufacturing

2001 ◽  
Author(s):  
M. Haberer ◽  
G. Zak ◽  
C. B. Park ◽  
M. Paraschivoiu ◽  
B. Benhabib
Keyword(s):  
Fluid Mechanics ◽  
Cross Sections ◽  
Manufacturing System ◽  
Layered Composite ◽  
Layered Manufacturing ◽  
Thin Layers ◽  
Prototype System ◽  
Slot Coating ◽  
Parts Manufacturing ◽  
The Relationship

Abstract This paper addresses the fluid mechanics of the slot-coating process within the context of the layered manufacturing system. The investigation was carried out to assist with the design of a novel slot-coating-based liquid-layer-formation subsystem. This subsystem, when used as a part of a lithography-based Rapid Layered Composite parts Manufacturing (RLCM) system, successfully solves some of the difficulties encountered in the formation of thin layers from a highly viscous fibre-photopolymer composite liquid. In addition to an analytical model, the paper presents a numerical model based on a volume of fluid (VOF) algorithm. The algorithm allows (1) solution of non-steady-state problems, (2) tracking of the free surface of the fluid undergoing large deformations, and (3) easy modification of model’s domain to facilitate experimentation with coater geometry. Results from a set of simulated experiments are reported which show the relationship between the liquid coat height and several design and process parameters. Examination of cross-sections of test parts built on an RLCM prototype system confirmed the ability of the new coater design to form solid layers of good quality.

Sign in / Sign up

Export Citation Format

Share Document