• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.9
• /
• pp.53-61
• /
• 2000

The manufacture of a marine propeller typically requires long lead time to generate 5-axis tool path. Hence it may take several weeks to manufacture a satisfactory propeller with a general purpose CAD/CAM system. In this research a dedicated 5-axis CAD/CAM system for machining marine propellers has been developed, The system employs various methods to enhance the productivity : interference-free tool path generation employing check vectors and optimum cutter size determinants. In addition an iterative NURBS modeling technique is used to improve the accuracy of the modeled surface and effective cutting conditions are determined and recommended empirically to increase the productivity. The proposed CAD/CAM system has been implemented with C++ and OpenGL graphic library on the Windows system. The system validation and sample results are also given and discussed.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.11 no.3
• /
• pp.1-8
• /
• 2002

This study is continuous with the study I (A Study on the Modeling) and the sample impeller of this study is defined by the modeling process of the exclusive CAD/CAM system developed in the study Ⅰ. And, this study describes a method for the 5-axis machining of impeller blades formed by ruled surface. Therefore, the exclusive CAD/CAM system is the software for modeling md machining of impeller blades. By using the machining method suggested in this study, we could manufacture impeller blades on 5-axis CNC machining center and the machined impeller was very agreeable to the designed impeller. Thus, theories proposed in this study can be very useful for the 5-axis machining of impeller blades.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.7 no.1
• /
• pp.126-134
• /
• 1998

In order to increase the modeling power and productivity of CAD/CAM systems, demands for customization of CAD/CAM system increased. Customization of a CAM system involves making it easier to learn and use, adding new modeling features not supported in a general purpose CAM system, and providing parametric inputting mechanism. A customization from a commercial CAM system (OMEGA) has implemented for two dimensional free curve CNC glass scribing machine of medium size company in Cheonan. A CAD technician who has no CAM experience can operate this customized CAM system satisfactorily.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1993.04b
• /
• pp.277-280
• /
• 1993

CAD/CAM 시스템의 중요성에 대해서 많은 사람들이 인식하고 있으나, CAD/CAM 시스템의 장비 가격이 비싸고,시스템을 작동시키기 위해 전문인력도 필요하다. 대부분의 CAD/CAM 시스템에서 컴퓨터로는 Workstation을 이용하는 경우가 많아서 CAD/CAM 시스템의 유지 보수에많은 비용을 지출하여야하므로 중소업체에서는 시스템의 도입이 어려운 실정이다. 또한 CAD/CAM 시스템이 주로 외국에서 개발되었기에 모든 작동 명령어나 메시지도 외국어를 사용하고있다. 따라서 외국에서 개발된 CAD/CAM 시스템에 익숙해지는 데는 시간이 걸리며 자신이 사용하는 기능외에 다른 기능을 사용하지 않는 경우가 많다. 본 연구에서는 위의 문제점들을 다소나마 해결하기 위하여 다음과 같이 1) 저렴한 장비비 및 유지비를 위하여 IBM PC 호환기종을 사용하였으며, 2) 사용의 편리성을 위해서 사용자와의 대화에 있어한글과 그래픽을 이용하였고, 3) NC 코드의 생성에 있어 NC 기계에서 제공되는 기능들을 활용하여 NC 코드의 길이를 최소화 하였으며 4) 형상 입력, NC 코드 Download 등이 한 프로그렘에서 이루어 지도록 하였다.

• Journal of the Korean Society for Precision Engineering
• /
• v.10 no.1
• /
• pp.52-61
• /
• 1993

Developed in this research is a CAM system for 5-axis NC Machining of sculptured surfaces. We identify problems in generating 5-axis NC data and propose methods of overcoming them. Issues discussed in this paper are: kinematic modelling of NC machines; determination of cutter position (location and orientation); check of machine work-range; linear trajectory plann- ing ; calculation of feedrate number. The proposed system has been implemented in FORTRAN77 on the Personal IRIS EWS, and it also constitutes a module of the CAD/CAM system 'CASSET' developed in KIST CAD/CAM lab.

• Journal of the KSME
• /
• v.33 no.4
• /
• pp.330-342
• /
• 1993

CAD/CAM이 국내에 도입되기 시작한 것은 70년대 후반이나, 본격적으로 보급되어 사용되기 시작한 것은 80년대 초부터라 하겠다. 도입초기에는 설계의 획기적인 변화를 약속해주는 새로운 기술로 각광을 받아오고, 또한 몇몇 분야에서는 그만한 가능성을 보여주기도 하였으나, 설계실 에서 컴퓨터가 제도판을 밀어내기 시작한지 약 10년이 지난 이 시점에서 돌이켜보건대 과연 CAD/CAM이 초기의 커다란 기대에 부응하는 성과를 올리고 있는 가에는 의문이 가는 것도 부 인할 수 없는 사실이다. 이는, 여러 가지 해석이 있을 수 있겠으나 필자의 견해로는 다음의 4가 지에 주로 기인한다. 1) CAD/CAM시스템 자체의 기능 및 성능 부족 2) 이기종 시스템간의 인터페이스 기술의 부족 3) 산업현장의 설계표준, 정보관리체계 등의 기반환경 미비 4) 적용 대상에의 전용화(customizing)기술의 부족 이 글에서는 이러한 원인들의 부분적인 해결을 위해서 필자가 속해있는 회사에서 수행한 노력 들을 몇 가지 사례를 통하여 소개하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.9 no.2
• /
• pp.270-275
• /
• 2008

The straight bevel gear for automobile part has been manufactured by the cold forging instead of the gear machining tool for the mass production. The application to CAD/CAM system has been necessary in order to develop the precision product quickly by forging through the minimization of trial and error and confirm the reproducibility. In the study, the straight bevel gear with the crown teeth has been modelled by the CAD/CAM system. The master gear after the gearing test has been machined after the modelling, NC data generation and verification. The die for forging and the jig for machining has been manufactured using the master gear.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.14 no.2
• /
• pp.83-90
• /
• 2005

A mirror cam mechanism a kind of conjugate cam mechanism consists of two cams, two rollers, and two links. Since profiles of two mirror cam are identical, a simultaneous machining of two cams is achievable. Some machining errors on cam profiles do not result in the internal acting force, which often causes problems in high speed cam mechanism between two links. Also, since angular accelerations of two links are same, the internal acting force by the difference of the angular accelerations does not occur in the mechanism. Thus the mirror cam mechanism is very useful in high speed machinery. This paper studies a design method as well as a machining method, and develops an exclusive CAD/CAM software for mirror cam profiles. The developed CAD/CAM software is applied to a typical mirror cam mechanism and a mock-up equipment is built in order to test the machinism mirror cm. Experimental investigations show that the contact between cam surface and roller surface according to cam rotation agrees well with the simulation on the developed CAD/CAM software.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1992.04a
• /
• pp.317-322
• /
• 1992

Developed in this reseach is a CAM system for 5-axis NC Machining of sculpture surfaces. We identify problems in generating 5-axis NC data and propose methods of overcoming them. Issues discussed in this report are; kinematic modelling of NC machines; Determination of cutter position(location and orientation); check of machine work-range; linear trajectory planning; calculation of feedrate number. The proposed system has been implemented in FORTRAN77 on the Personal IRIS EWS, and it also consitutes a module of the CAD/CAM system 'CASSETTE' developed in KIST CAD/CAM lab..

• Journal of Technologic Dentistry
• /
• v.35 no.2
• /
• pp.89-95
• /
• 2013

Purpose: The purpose of this study was to evaluate bond strength of Metal Disk alloy and casting alloy. Methods: Metal specimens were divided into 4 groups for each alloy. Three point flexural test were used to measure the bond strength of CAD/CAM metal alloy and casting alloy. Statistical analysis was done using the Statistical Package for Social Sciences version 19.0 for Windows. As for the analysis methods, the study used Kruskal-Wallis test. Results: The average bonding strengths of Group 1 to porcelain was $36.7{\pm}9.90$ MPa, Group 2 to porcelain was $37.68{\pm}4.51$ MPa, Group 3 to porcelain was $36.43{\pm}6.57$ MPa, Group 4 to porcelain was $42.88{\pm}6.81$ MPa, Each group was not significantly different. Conclusion: Bond strength of Casting alloy is equal to or higher than bond strength of CAD/CAM Metal Disk alloy. Alloy clinical bond strength is 25 MPa, So CAD/CAM Metal Disk alloy can be used as dental material.