• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.759-762
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• 2000

Rapid Prototyping (RP) techniques have their unique characteristics according to the working principles: stair-stepped surface of parts due to layer-by-layer stacking, low build speed caused by line-by-line solidification to build one layer, and additional post processing to improve surface roughness, so it is required very high cost to introduce and to maintain RP apparatus. The objective of this study is to develop and design a new RP process, Variable Lamination Manufacturing using expandable polystyrene foam sheet as part material (VLM-S), which can make up for the disadvantage of existing techniques, and to develop an apparatus to implement the process. In order to examine the possibility of practical utilization of the proposed VLM-S process for prototyping of a general three-dimensional shape, an auto-shift lever knob and a pyramid shape were fabricated.

• Journal of the Korean Society for Precision Engineering
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• 제21권10호
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• pp.188-195
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• 2004

In this paper, we fabricated fluidic devices like micro-channel, pump, mixer and particular gas separator with the technology of stereolithouaphy using RP(rapid-prototyping). The fabricated fluidic devices are expected to be applied to develop Lab-on-a chip type liquid analyzer. Stereolithography technology seems effective for fabricating MEMS(Micro Electro Mechanical System) with complicated structure because it makes three dimensional fabrication possible but, exclusive devices are needed to be developed fur fabricating even more microscopic MEMS structure.

• Korean Journal of Computational Design and Engineering
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• 제6권1호
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• pp.48-58
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• 2001

One of the biggest problems of rapid prototyping(RP) technologies lies in their standard file format for CAD data exchange. Current methods using the de facto industry standard 'STL'have at times resulted in problems such as accuracy, redundancy, and integrity. In this paper we propose a STEP based data exchange framework for rapid prototyping systems. In this paradigm of data exchange, STEP models can be imported and converted into faceted B-rep. solid models for visualization and 2-D layer data for RP. Also an STL model, on the other hand, can be converted into a faceted B-rep. STEP model and exported as a new data exchange model with RP information.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.753-756
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• 2005

Rapid prototyping (RP) technologies are mainly performed by layered manufacturing (LM) process which manufactures 3D physical objects by depositing 2D sections in a direction. Thus, deformations are apt to occur in overhanging area of the RP processed part. Also, excessive adhesion between part and platform of the RP apparatus is generated. In order to prevent these problems, most of the RP technologies adopt support structure. Main element to support a part in the support structure is strand. In actual field, however, the number of strand is determined by the software operating reference guide or RP system operator's experience. In this paper, a methodology to determine the optimal strand spacing is presented through experiments and measurements for the SL part deformation by change of strand spacing and part weight in the support structure of the stereolithography.

• Journal of the Korean Society of Manufacturing Process Engineers
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• 제11권3호
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• pp.146-153
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• 2012

RP system which is widely used to reduce the time of product development is to resolve the problem of cutting work. It is a method using laminated thin films to produce many forms. The RP equipment used for this experiment is FDM system. This can produce 3D model with using 3D CAD designed file within a relatively short time. Not only this, this system also through 3D file preparation, 3D product manufacture, removal support these 3 step operating process can easily produce goods, but product can be different from original design. This research has been conducted to minimize this error. To apply to the circular product made a circular specimen and measured several times with 3D scanner and find out average 99.622% of accuracy. This result is applied to RP system, and with this changed design produced a specimen, and found out the accuracy is increased to 99.958%. If this is applied to circular products, we can produce more precise products with less process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.767-770
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• 2000

A novel process is newly developed for building RP(Rapid Prototyping) parts using a sheet lamination technique. The build process of existing sheet lamination type RP machines consists of the following steps : feeding, lamination and cutting. In this process, the laminated part of an object is often scratched by a cutter or damaged by a laser beam due to the cutting operation preceded by lamination, In addition, decubing of the unused portion from the laminated block is difficult. In the new process, cutting operation is performed before lamination. The cutting operation takes place while a paper sheet is firmly attached on the plate using electrostatic force. Then liquid glue is applied to the calculated region of the given contour for lamination. The process aims to manufacture a $2k RP machine, what we call the Freeform Mater I, that can use A4 or latter-size used papers. A prototype machine that demonstrates the design concept is built and further research issues are discussed.

• Journal of Welding and Joining
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• 제23권2호
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• pp.47-51
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• 2005

Rapid Prototyping (RP) technology has helped successfully to reduce time and costs since first emerged in 1986. Recently, RP using functional materials like as metal have been researched. However RP using molten metal and brazing material have been struggling to resolve several drawbacks, such as dimensional inaccuracy, poor surface finish and post finishing because occurring shrinkage and warpage at cooling. So, the purpose of this study is to develop a new RP technique using sheet metal and projection welding for reducing several drawbacks in occurring RP using molten metal. And optimum process variables were determined using desist of experiment(DOE).

• Journal of the Korean Society for Precision Engineering
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• 제25권11호
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• pp.126-133
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• 2008

Rapid Prototyping (RP) has been widely used for rapid development of prototypes in various industrial fields. In recent years, a new requirement in RP industry has issued so as to directly manufacture a functional prototype which has enough mechanical properties to be used as a functional part. The RP prototype, however, has a limitation in mechanical properties due to its layer-by-layer manufacturing process. This manufacturing process results in anisotropy of the prototype, especially showing weakness in the building direction. In the present work, we performed tensile tests for RP prototypes in order to determine directional mechanical properties. The test specimens were made by using $Eden330^{TM}$ by Object Geometries Ltd. Finite element analyses considering material anisotropy were then carried out for RP prototypes with various building directions. Effect of the building direction on the mechanical strength was investigated through the analysis, and compared with experimental results.

• CDE review
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• 제13권1호
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• pp.5-7
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• 2007

• CDE review
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• 제14권2호
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• pp.6-11
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• 2008