• Journal of Korea Foundry Society
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• v.21 no.5
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• pp.290-295
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• 2001

We fabricated test samples containing various shape elements and surface roughness checking points for the jewelry cast master patterns by employing the 3D computer aided design (CAD), selective laser sintering (SLS) rapid prototype (RP) with the DuraForm powders. We varied the alignment angle from $0^{\circ}$ to $10^{\circ}$ at a given layer thickness of 0.08 and 0.1mm, respectively, in RP operation. Dimensions of the shape elements as well as values of surface roughness are characterized by an optical microscope and a contact-scanning profilometer. Surface roughness values of the top and vertical face increased as the alignment angle increased, while the other roughness values and shape elements variation were not depending on the alignment angle. The resolution of the shape realization was enhanced as the layer thickness became smaller. The minimum diameter of the hole, common in jewelry design, was 1.2 mm, and the shrinkage became 12% at the 1.6 mm-diameter hole, Our results implied that we face down the proposed design elements with $0^{\circ}$ alignment angle, and consider the shrinkage effect of each shape element in DuraForm RP jewelry modeling.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.8 s.185
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• pp.203-210
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• 2006

This paper focuses on the development of RT technology suitable for manufacturing a small quantity of metal prototype of a precise part from an RP master. Dimensional accuracy and surface roughness are evaluated from Thermojet part of a 3D printer, and effective post-processing method is introduced. Investment casting is done using a prototype built from 3D printer as a wax pattern. Ceramic shell investment casting technique is developed to build a prototype with materials mostly wanted. Also, experimental result shows this research is very useful in manufacturing of a small quantity of functional part or a test part of a specific material.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.334-337
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• 2005

The objective of this research works is to propose a rapid development methodology of small size deep drawing tools for electronic parts utilizing the technology combination of CAE and RP/RT. The technology is applied to the development of deep drawing tools with a drain shape. The final surface of tools is obtained from the evaluation of the formability using the CAE. In order to manufacture the physical prototype of tools fer try-out terming, several fabrication experiments are carried out for three types of rapid tool manufacturing technology. Through the fabrication experiments, the acceptable rapid manufacturing technologies of deep drawing tools with a small size have been proposed.

• Journal of International Society for Simulation Surgery
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• v.2 no.2
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• pp.76-79
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• 2015

One of the most serious complications after head and neck radiation is osteoradionecrosis (ORN) of the jaw. The etiology of ORN is extraction, minor dental procedure or dental implant surgery. When ORN of the jaw progressed to stage III, free fibular flap is the most useful methods for reconstruction. In this case report, a 67-year-old ORN patient who underwent fibular free flap reconstruction using simulation surgery with 3-dimensional rapid prototype (3D RP) model was reviewed. After partial mandibulectomy, a osteocutaneous fibula flap was used for reconstruction. Oro-cutaneous fistula was resolved after operation. Patients reported improved food intake after operation without pus discharge. Functional and esthetic results showed successful reconstruction.

• Journal of International Society for Simulation Surgery
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• v.3 no.2
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• pp.60-63
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• 2016

Fibrous dysplasia is quite a rare disease usually involving maxilla and mandible. Because of its benign clinical course, conservative contouring surgery has been recommended for facial deformity. 3D rapid prototype (RP) model gives a lot of informations before operation such as depth of drilling, area of resection and important anatomic structure. The purpose of this study was to report maxilla-mandibular contouring surgery in fibrous dysplasia patients. A total of 14 consecutive patients were included for surgical and esthetic evaluation. Among 14 patients, RP model study was performed in two patients with severe facial deformity. The other patients underwent contouring surgery under conventional methods. Surgical evaluation was performed with computed tomography scan before and after operation. Surgical resection was successful and patients were satisfied with the surgical results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.3 s.174
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• pp.769-776
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• 2000

RP(Rapid Prototyping) technology is gaining its popularity in building a prototype in all industries. SLS(Slective Laser Sintering) is one of RP technologies, which is focused on tooling processes as well as three dimension solid model. There are several factors, the length and the cross-sectional area of a part, that have an effect on build setup in SLS process. In this paper, the computation on geometrical relationship is used to slice STL file and to estimate these factors. Based on these values, the build setup parameters such as the heating temperature, the laser power, and the powder cartridge feed rate are determined by neural network approaches. The test results show that the computation time is saved and the neural network approach is able to apply to get the optimal parameters of build process within an acceptable error rate.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.4
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• pp.485-490
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• 2003

RP(Rapid Prototyping) has been used in the various industrial applications. This paper presents the optimization techniques fur fabricated 3D model design using RP machine for the medical field. Once the original brain model data are obtained from 2D slices of MRI/CT machine, the data can be modeled as an optimal ellipse. The objective of this study includes optimization of fabrication time and surface roughness using the adaptive slicing method. It can reduce fabrication time without losing surface roughness quality by accumulating the slices with variable thickness. According to the parameter tuning and synthesis of its effect, more suitable parameter values can be obtained by enhanced 3D brain model fabrication. Therefore, accurate 3D brain model fabricated by RP machine can enable a surgeon to perform pre-operation. to make a decision for the operation sequence and to perceive the 3D positions in prototype, before delicate operation of actual surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.2
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• pp.114-121
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• 2011

Introduction: The aim of this study was to demonstrate that the simulation surgery on rapid prototype (RP) model, which is based on the 3-dimensional computed tomography (3D CT) data taken before surgery, has the same accuracy as traditional orthograthic surgery with an intermediate splint, using an optoelectronic tracking navigation system. Materials and Methods: Simulation surgery with the same treatment plan as the Le Fort I osteotomy on the patient was done on a RP model based on the 3D CT data of 12 patients who had undergone a Le Fort I osteotomy in the department of oral and maxillofacial surgery, Seoul National University Dental Hospital. The 12 distances between 4 points on the skull, such as both infraorbital foramen and both supraorbital foramen, and 3 points on maxilla, such as the contact point of both maxillary central incisors and mesiobuccal cuspal tip of both maxillary first molars, were tracked using an optoelectronic tracking navigation system. The distances before surgery were compared to evaluate the accuracy of the RP model and the distance changes of 3D CT image after surgery were compared with those of the RP model after simulation surgery. Results: A paired t-test revealed a significant difference between the distances in the 3D CT image and RP model before surgery.(P<0.0001) On the other hand, Pearson's correlation coefficient, 0.995, revealed a significant positive correlation between the distances.(P<0.0001) There was a significant difference between the change in the distance of the 3D CT image and RP model in before and after surgery.(P<0.05) The Pearson's correlation coefficient was 0.13844, indicating positive correlation.(P<0.1) Conclusion: Theses results suggest that the simulation surgery of a Le Fort I osteotomy using an optoelectronic tracking navigation system I s relatively accurate in comparing the pre-, and post-operative 3D CT data. Furthermore, the application of an optoelectronic tracking navigation system may be a predictable and efficient method in Le Fort I orthognathic surgery.

• Journal of International Society for Simulation Surgery
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• v.1 no.1
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• pp.32-36
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• 2014

Reconstruction of the maxilla is quite a difficult challenge for reconstructive surgeons. The maxilla is the most important part of the midface, which contributes to facial esthetics, mastication, swallowing, speech, supporting orbital contents and sinus function. Free fibular flap is most versatile to reconstruct jaw bone because of its adequate length, containing both soft and bony tissues and acceptance of dental implants. In this case report, a reconstruction of the maxilla using free fibular flap and dental implants is described in which rapid prototype was used before surgery to simulate the final prosthetic results.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.5
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• pp.104-109
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• 2001

Nowadays, Industrial competition power is depended on that rapidly produce the customized products. Therefor, it is necessary to reduce period of product development. Thus, concurrent engineering that work many process at a time was appeared and Rapid prototyping was appeared, it is method that rapidly produce the prototype. If the graphic model was made by CAD, the prototype can be made in short term. That provide what the part was directly tested by the worker. It provide a worker with believable data. We study on the influence of surface roughness on injection interval and part angle at FDM.