• 소성∙가공
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• 제14권3호
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• pp.187-199
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• 2005

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.536-539
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• 2002

The reverse engineering (RE) technology can quickly generate 3D point cloud data of an object by capturing the surface of a model using a 3D scanner. In the rapid prototyping (RP) technology, prototypes are rapidly produced from 3D CAD models in a layer-by-layer additive basis. In this paper, a physical human head shape is duplicated using a new RP process, the Transfer-type Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-ST), after the point cloud data of a human head shape measured from 3D SNX scanner are converted to STL file. From the duplicated human head shape, it has been shown that the VLM-ST process in connection with the 3D scanner is a fast and efficient process in that shapes with free surface, such as the human head shape, can be duplicated with ease. Considering the measurement time and the shape duplication time, the use of 3D SNX scanner and the VLM-ST process is expected to reduce the lead-time fur the development of new products in comparison with the other existing RE-RP connected manufacturing systems.

• 동력기계공학회지
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• 제6권2호
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• pp.54-59
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• 2002

The principle of the FDM(fused deposition modeling) process is based on the layer by layer manufacturing technology, like other RP(rapid prototyping) process. In the FDM process, each layer may have different shape. Therefore, the built model may have stairs shape on its surface. This stairs shape is one of the serious problems in the FDM process. Thus in this study, cube models and spherical models were fabricated by FDM process to investigate the influence of injection amount on surface roughness. Models with various road width were also built to investigate the influence of road width on surface roughness. Surface roughness of the models was measured and analyzed. The result obtained in this study are expected to help selecting the part build orientation for optimum surface roughness.

• 한국정밀공학회지
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• 제18권8호
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• pp.54-63
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• 2001

Rapid Prototyping(RP) techniques have their unique characteristics according to the working principles: stair-stepped surface of a part due to layer-by-layer stacking, low build speed caused by point-by-point or line-by-line solidification to build one layer, and additional posts processing to improve surface roughness, so high cost is required to introduce and to maintain the RP apparatus. The objective of this study is to develop a new RP process, Variable Lamination Manufacturing by using expandable polystyrene foam sheet as part material(VLM-S), and to design an apparatus for implementation of the process. So, the process parameters and design criterions of the apparatus were defined and the techniques were proposed to satisfy the design criterion. Based on the results, a knob-shape, pyramid shape. and a solid block were fabricated on the apparatus in which unit shape part(USP) was generated for building each layer.

• 한국정밀공학회지
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• 제18권8호
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• pp.64-70
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• 2001

In all the Rapid Prototyping (RP) techniques, the computer-aided design (CAD) model of a three-dimensional part is sliced into horizontal layers of uniform, but not necessarily constant, thickness in the building direction. Each cross- sectional layer is successively deposited and, at the same time, bonded onto the previous layer. The stacked layers form a physical part of the model. The objective of this study is to develop a software for automatic generation of unit shape part(USP) for a new RP process, Variable Lamination Manufacturing using the linear hotwire cutting technique and expandable polystyrene foam sheet as part material(VLM-S). In order to examine the applicability of the developed software to VLM-S, USPs of general three-dimensional shapes, such as an auto-shift lever knob and a pyramid shape were generated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.50-53
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• 2003

Most companies use technologies such as stereolithography, selective laser sintering, and fused deposition modeling to make parts for such small consumer products as telephones, heads, and shoes. The largest part that the existing RP systems can make is only 600 mm in length. Because most RP systems build parts by depositing, solidifying, or sintering material point-by-point, making larger objects takes a long time. and in many cases, large objects won't fit the build size. A new effective thick-layered RP process. Transfer type Variable Lamination Manufacturing using expandable polystyrene foam (VLM-ST) has been developed with thick layers and sloped surfaces. In this paper, a scaledown model of F16 Fighter with the length of 800 mm is rapidly fabricated using the VLM-ST process. In order to build a CAD model of F16 larger than 600 mm in length, the approach in VLM-ST is to build larger parts in multiple sub-parts and then glue them together. The fabricated result shows that the VLM-ST process employing thick layers and sloped surfaces is adequate for creating the real-sized large objects in the diverse fields such as automobiles, electric home appliances, electronics. and etc.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.771-774
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• 2000

RP techniques have inherent disadvantages caused by their working principles: stair-stepped surface of parts due to layer-by-layer stacking of layers, low build speed caused by line-by-line solidification to finish one layer, and post processing to improve surface finish, etc. The objective of this study is to propose a new RP technique, variable deposition manufacturing (VDM), which can make up for the disadvantages of the existing RP techniques, and to develop an apparatus to implement the technique. The proposed process can greatly reduce the building time and improve the surface finish of parts generated. The experiments are carried out to obtain the range of temperature of molten material to maintain its fluidity and to investigate the effect of gas cooling on the preservation of the slopes. Based on the results, some simple shapes such as a line-shape. an S-shape, and a circle-shape were fabricated from Ethylene Vinyl Acetatecopolymer (EVA). In order to examine the applicability of VDM to more general shapes, a tensile specimen and a yo-yo shape were manufactured by the proposed RP method using EVA material as the first trial approach. The present basic study has shown the possibility of a practicable utilization of the proposed VDM process to prototyping of a general three-dimensional shape.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.599-602
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• 2002

A novel rapid prototyping (RP) process, an automated transfer type variable lamination manufacturing process (Automated VLM-ST) has been developed. In Automated VLM-ST, a vacuum chuck and linear moving system transfer the plate type material with two pilot holes to the rotation stage. A four-axis synchronized hotwire cutter cuts the material twice to generate Automated Unit Shape Layer (AUSL) with the desired width, side slopes, length, and two reference shapes in accordance with CAD data. Each AUSL is stacked on the stacking plate with two pilot pins using the pilot holes in AUSL and the pilot pins. Subsequently, adhesive is supplied to the top surface of the stacked AUSL by a bonding roller and pressure is simultaneously applied to the bottom surface of the stacked AUSL. Finally, three-dimensional shapes are rapidly fabricated. This paper describes the procedure for generating the cutting path data (AUSL data) f3r automated VLM-ST. The method for the generation of the Automated Unit Shape Layer (AUSL) in Automated VLM-ST was practically applied and fabricated for a various shapes.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.1037-1041
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• 2001

Competitive power is rapidly manufacture product required consumers. Therefore, modern industry have changed from small item many production to many item small production, rapid production is necessary thing at the product development. Thus, rapid prototyping is appeared. If the graphic model was made by CAD, the production can be made in short term. That provide what the part was directly tested by the worker. It provide believable data. This study is Imfluence of Surface roughness on Rapid prototyping by FDM(Fused deposition modeling).

• 한국산학기술학회논문지
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• 제8권4호
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• pp.775-780
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• 2007

쾌속조형기술(Rapid Prototyping Technology)은 설계단계에 있는 3차원 모델을 시제품(Prototype)으로 다른 중간과정 없이 빠르게 생성하는 새로운 기술을 말한다. CAD 모델 데이터는 3차원 형상 시스템이지만 모니터 화면이나 문서로 출력할 때는 2차원으로 밖에 표시되지 않는다. 반면에 쾌속조형기술은 설계된 3차원 CAD 데이터를 2차원 단면 데이터로 변환한 후 RP(Rapid Prototyping)공정을 적용하여 순차적으로 적층해 감으로써 CAD 데이터와 같은 3차원 입체 형상을 제작하게 된다. 그러나 RP 시스템은 매우 가격이 비싸서 칫솔이나 완구 등과 같은 생활용품을 제작하는 중소기업에서는 구입하기 어려운 상황이다. 본 논문에서는 오픈소스를 사용하여 RP 기술을 구현함으로써 저렴한 가격으로 구매할 수 있는 RP 시스템을 개발하기 위한 3차원 제어시스템을 제안하였다.