• The korean journal of orthodontics
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• v.50 no.6
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• pp.401-406
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• 2020

Objective: To investigate and compare the slot sizes and parallelism of metal injection molding (MIM) and computerized numerical control (CNC) brackets. Methods: The following four MIM bracket series with 0.022-inch (in) slots were selected for investigation: Di MIM mini Twin (Ortho Organizers), Mini Diamond Roth (Ormco), Gemini MBT (3M Unitek), and Formula R Roth (Tomy). The following four CNC bracket series with 0.022-in slots were selected for investigation: Econoline MBT (Adenta), Legend mini MBT (GC Orthodontics), Crown mini MBT (Adenta), and Evolve MBT (DB Orthodontics). The slot dimensions were measured using an optical microscope (XTCam-D310M; Mitutoyo) with a resolution of 1 ㎛. The results were statistically analyzed using one-way analysis of variance and the Tukey post-hoc test with a significance level of 0.05. Results: The results indicated that all the investigated slot sizes were oversized with respect to the manufacturers' specifications (0.022 in). Among the eight bracket series, the Di MIM bracket (MIM) was the most oversized by 10.4%, whereas the Evolve bracket (CNC) was the least oversized by 2.6%. The slots in seven of the bracket series had divergent walls instead of parallel ones. The Evolve bracket alone had parallel slot walls. Conclusions: Regardless of the manufacturing method, all the slot sizes of the brackets investigated in this study were significantly oversized; most of the slot walls were nonparallel, except for those of the Evolve bracket. This study could not establish that the CNC method was more accurate than the MIM method in manufacturing bracket slots.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.4
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• pp.7-15
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• 2009

• Journal of Korea Technology Innovation Society
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• v.3 no.2
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• pp.78-93
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• 2000

Since computerized numerical controller(CNC) emerged as a result of the fusion of the electronics technology and the mechanical technology, there has been continuous evolution of CNC technology in the mechatronics industry. The industry is recently developing a new control system based on the fusion of personal computer(PC) and CNC. Upgraded PC has now integrated into CNC, making various machines possible to exchange data, software and hardware, and to greatly improve man-machine interface. The fusion of PC and CNC can form a new paradigm in technological innovation of not only control system but also whole machinery industry in near the future. Korea lagged behind the developed countries in the development of open control system with the fusion of PC. Turbotek, Hyundai Motor and Daewoo are leading companies, but their commercial possibility seems to be low because domestic market is too small to reap a commercial benefit. Nevertheless, the development of the system is an essential step for Korea to embark on a future technological paradigm of the machinery industry. The government needs to play some role for the development, for instance, government R&D projects, institutional building and training of related technicians.

• Journal of Mechanical Science and Technology
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• v.20 no.4
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• pp.455-466
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• 2006

This study was an attempt to control and monitor Computerized Numerical Controller (CNC) machines anywhere and anytime for the development of a ubiquitous machine (u-machine). With a Personal Digital Assistant (PDA) phone, the machine status and machining data of CNC machines can be monitored in wired and wireless environments, including the environments of IMT2000 and Wireless LAN. Moreover, CNC machines can be controlled anywhere and anytime. The concept of the anywhere-anytime controlling and monitoring of a manufacturing system was implemented in this study for the purpose of u-manufacturing and u-machines. In this concept, the communication between the CNC controller and the PDA phone was successfully performed anywhere and anytime for the real-time monitoring and control of CNC machines. In addition, the interface between the CNC controller and the developed application module was implemented by Object linking and embedding for Process Control (OPC) and shared CNC memory. For communication, the design of a server contents module within the target CNC was based on a TCP/IP. Furthermore, the client contents module within the PDA phone was designed with the aid of embedded c++ programming for mobile communication. For the interface, the monitoring data, such as the machine status, the machine running state, the name of the Numerical Control (NC) program, the alarm and the position of the stage axes, were acquired in real time from real machines with the aid of the OPC method and by sharing the CNC memory. The control data, such as the start, hold, emergency stop, reserved start and reserved stop, were also applied to the CNC domain of the real machine. CNC machines can therefore be controlled and monitored in real time, anywhere and anytime. Moreover, prompt notification from CNC machines to mobile phones, including cellular phones and PDA phones, can be automatically realized in emergencies.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.10
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• pp.977-981
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• 2015

We propose a method for the implementation of an EtherCAT communication bus in a Linux-based open source Computerized Numerical Control (CNC) system. Recently, increasingly more CNC systems support real-time Ethernet protocols such as EtherCAT, which is a high-performance industrial communication protocol. For real-time CNC control over an Ethernet-based protocol, an additional layer driver needs to be implemented between the CNC system and the master of industrial communication protocol. Among the various solutions for the connection layer driver, we employ a Hardware Abstraction Layer (HAL) driver based on Linux. The operation of the implemented CNC system is demonstrated and confirmed by Hal Meter, which is used to observe the pins, signals, or parameters of HAL.

• Journal of the Korea Institute of Building Construction
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• v.13 no.5
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• pp.434-440
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• 2013

Generally, the envelope of a freeform building is composed of a structure made with rectangular or C-shaped steel pipe, and steel or aluminum panel finishes on the structure. However, these construction methods increase material loss and cost and time. There are also numerous cases of misunderstanding of design and difficulties in construction, which frequently cause construction errors. Such construction errors decrease construction productivity, resulting in poor construction quality and the need for rework, as well as cost and time overruns. To solve the problem, this study proposes a 3D coordinate control technology for freeform structure implemented through a CNC(Computerized Numerical Control) Twisted tube method, and by extension, develops a BIM-based envelope construction method for freeform building.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2000.05a
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• pp.154-173
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• 2000

Since computerized numerical controller (CNC) emerged as a result of the fusion of the electronics technology and the mechanical technology, there has been continuous evolution of CNC technology in the mechatronics industry. The industry is recently developing a new control system based on the fusion of personal computer (PC) and CNC. Upgraded PC has now integrated into CNC, making various machines possible to exchange data, software and hardware, and to greatly improve man-machine interface. The fusion of PC and CNC can form a new paradigm in technological innovation of not only control system but also whole machinery industry in near the future. Korea lagged behind the developed countries in the development of open control system with the fusion of PC. Turbo-tek, Hyundai Motor and Daewoo are leading companies, but their commercial possibility seems to be low because domestic market is too small to reap a commercial benefit. Nevertheless, the development of the system is an essential step for Korea to embark on a future technological paradigm of the machinery industry. The government needs to play some role for the development, for instance, government R&D projects, institutional building and training of related technicians.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.1032-1035
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• 2000

Increasing demands on precision machining with computerized numerical control (CNC) machines have necessitated that the tool to move not only position error as small as possible, but also with smoothly varying feedrates in space. This paper presents a new high precision interpolation algorithm for 3-dimensional (3D) Non-Uniform Rational B-Spline (NURBS) curve in the reference-pulse CNC technique. Based on the minimum path error strategy, real-time NURBS interpolator was developed in software and this was implemented with a PC-NC milling machine. The several experimental results have shown that the proposed NURBS interpolator is useful for the high precision machining of complex shapes. It is expected that this algorithm can be applied to the CNC machines for the machining of 3D free-form surfaces.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.5
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• pp.115-121
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• 1996

Recently, the Z-Map model has been used widely to represent the three dimensional geometric shape and to achieve the cross-section and point evaluation of the shape. In this paper, the CNC cutting planning and simulation modules for product with three dimensional geometric shape are realized based on the Z-Map model. The realized system has the various capabilities related to the automatic generation of tool path for the rough and finish cutting processes, the automatic elimination of overcut, the automatic generation of CNC program for a machining center and the cutting simulation. Especially, the overcut-free tool path is obtained by using the CL Z-Map models which are composed of the offset surfaces of the geometric shape of product.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.750-753
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• 2005

Internet service, a part of our life, requires the changes not only of environment in our life but also of people's sense of value. It also requires a quick change in the spear of education activities without exception. It brought a lot of changes into educational methods, our recognition on education, and various kinds of educational tools and environment. The introduction of WBI (Web Based Instruction) is one of the most important thing. This study have applied WBI to Industrial high school education to improve its quality and accomplish its effective teaching-learning. That is, we have applied CNC(Computerized Numerical Control) and Processing learning to machining center learning and have given students chances and various learning materials so that they could contact with new information. We aimed at testing and studying some effects on the improvements of learning accomplishment and motive in this study.