• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.716-721
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• 2004

Several Solid Freeform Fabrication Systems(SFFS) are commercialized in a few companies for rapid prototyping. However, they have many technical problems including the limitation of applicable materials. A new method of speedy prototyping is required for the recent manufacturing environments of multi-item and small quantity production. The objectives of this paper include the development of a novel method of SFFS, the ${CAFL}^{VM}$(Computer Aided Fabrication of Lamination for Various Material), and the manufacture of the various material samples for the certification of the proposed system and the creation of new application areas. For these objectives, the technologies for a highly accurate robot path control, the optimization of support structure, CAD modeling, adaptive slicing was implemented. In this paper, we design an algorithm that the cutting path of a laser beam which is controlled with constant speed. The laser beam is tangentially controlled in order to solve the inaccuracy of a 3D model surface. The designed algorithm for constant-speed path control and tangent-cutting control is implemented and experimented in the ${CAFL}^{VM}$ system.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.1
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• pp.1-11
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• 2005

Several Solid Freeform Fabrication Systems(SFFS) are commercialized in a few companies for rapid prototyping. However, they have many technical problems including the limitation of applicable materials. A new method of agile prototyping is required for the recent manufacturing environments of multi-item and small quantity production. The objectives of this paper include the development of a novel method of SFFS, the CAFL/sup VM/(Computer Aided Fabrication of Lamination for Various Material), and the manufacture of the various material samples for the certification of the proposed system and the creation of new application areas. For these objectives, the technologies for a highly accurate robot path control, the optimization of support structure, CAD modeling, adaptive slicing was implemented. However, there is an important problem with the conventional 2D lamination method. That is the inaccuracy of 3D model surface, which is caused by the stair-type surface generated in virtue of vertical 2D cutting. In this paper, We design the new control algorithm that guarantees the constant speed, precise positioning and tangential cutting on the 5DOF SFFS. We develop the tangential cutting algorithm to be controlled with constant speed and successfully implemented in the 5DOF CAFL/sup VM/ system developed in this paper. Finally, this paper confirms its high-performance through the experimental results from the application into CAFL/sup VM/ system.

• Restorative Dentistry and Endodontics
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• v.12 no.1
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• pp.131-147
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• 1986

The purpose of this study was to observe the color matching of lining or filling materials according to the remaining tooth material. Twenty-seven freshly extracted human central incisors were used in this experiments. The teeth were stored in saline solution at room temperature after extraction. All teeth were cut parallel to the tangent to height of contour on labial surface from the lingual surface until the pulp were completely removed. Then 27 teeth were devided into 0.5mm, 1.0mm and 1.5mm reduction groups according to the thickness of cutting the lingual surfaces of teeth. The specimens of control group were three teeth of 27 teeth with cutting the lingual surface same mode as above described. In the specimens of experimental groups, 8 kinds of lining and filling materials; FUJI IONOMER TYPE II (G-C Co. Japan), LINING CEMENT (G-C Co. Japan), Dycal (Caulk, U.S.A.), CLEARFIL F II (Kuraray Co. Japan), Crown Bridge & Inlay Cement (G-C Co. Japan), Copalite (Harry J. Bosworth Co. U.S.A.), HY-BOND (G-C Co. Japan) and LIV-CENERA (G-C Co. Japan); applied on the back of 24 teeth with 0.5mm, 1.0mm and 1.5mm cut thickness of lingual surfaces. Three teeth of control group did not applied linging or filling materials on the back of 3 kinds of different thickness of cutting the lingual surfaces. The absorbances of total 27 specimens were obtained by reflection spectrophotometer. (Cary 17 D, Varian Co, U.S.A.) The following conclusions were drawn from above the results; 1. The absorbance patterns in both experiment and control groups were gradually decreased with increasing wavelength of spectra. 2. The absorbance patterns were not decreased in relation to the kinds of lining or filling materials, but the amount of the remaining tooth materials. 3. In 0.5mm reduction group, FUJI IONOMER TYPE II, LINING CEMENT, LIV-CENERA and Copalite applied on the back of cut lingual surface showed similar absorbance patterns as control group. 4. The specimens which were reduced up to 1.0mm thickness and lined with FUJI IONOMER TYPE II and LINING CEMENT showed the comparable absorbance patterns to the control group. 5. In case of HY-BOND application after 1.5mm reduction were observed the similar absorbance pattern as compared with control group. 6. When Dycal, CLEARFIL and Crown Bridge & Inlay Cement were applied to cut teeth surfaces, there were much differences of absorbance between control groups and experimental groups.