• Journal of the Korean Society for Precision Engineering
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• v.12 no.2
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• pp.123-134
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• 1995

In this paper, the fast force algorithm has been studied so that it is used to calculate cutting forces and to develope the NC verification system. The NC verification using the fast force algorithm can verify excessive cutting force which is the cause of deflection and breakage of tool, and adjust the feed rate and spindle speed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.5 no.3
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• pp.66-72
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• 1996

The applicability of a new method, termed the whirling motion concept, for the improvement of the surface finish in milling three-dimensional sculptured surfaces has been investigated. A method for implementing this concept o conventional NC machines that utilize a suitably configured attachment has been proposed. The tool path equation for the ball-end milling process, based on the surface-shaping system, has been obtained. Both results of the computer simulation and the experiment verified the proposed approach.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.03a
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• pp.149-154
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• 1996

The applicability of a new method, termed the whirling motion concept, for the iprovement of the surface finish in milling three-dimensional sculptured surfaces has been investigated. A method for implementing this concept on conventional NC machines that utilize a suitably configured attachment has been proposed. The tool path equation for the ball-end milling process, based on the Surface-Shaping system, has been obtained. Both results of the computer simulation and the experiment verified the computer simulation and the experiment verified the proposed approach.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.4 s.97
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• pp.220-228
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• 1999

The machining accuracy has been improved with the development of NC machine tools and cutting tools. However, it is difficult to obtain a high degree of accuracy when machining deep pocket with long end mill, since machining accuracy is mainly dependant on the stiffness of the cutting tool. To improve surface accuracy in machining deep pocket using end mill, the performance by down cut and up cut is compared theoretically and experimentally. To verify usefulness of up milling, various experiments were carried out. As a result, it is found that up milling produce more accurate surface than down milling in machining deep pocket. For effective application of up milling, various values in helix angle, number of teeth, radial depth of cut and axial depth of cut are applied in experiment.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.4
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• pp.606-612
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• 2010

This study took advantage of NC processing technique in order to recreate design in development process of leisure boat based on the Korean boats and ships. CNC milling is an area which is concerned in automation process of boat production and needs sophisticated software, equipment and professionals to pilot it. The progress of manufacture begins when the surface model creation and simulation being done using CAD/CAM software. In this process, the needs such as 3D design, NC processing data, plug lamination and partition processing appear as detailed steps. The study completed these detailed steps and also the application example has been studied with presenting engineering potentialities.

• Korean Journal of Computational Design and Engineering
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• v.4 no.4
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• pp.295-311
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• 1999

An increasing attention is paid to STEP-NC, the next generation CNC controller interfacing STEP-compatible data. In this paper, we first propose an Architecture for the STEP-NC (called FBCC: Feature Baled CNC Controller) accepting feature code compatible with STEP-data, and executing NC motion feature by feature while monitoring the execution status. The main thrust of the paper has been to develop an automatic on-line tool path generation and modification scheme for milling operation. The tool path it generated iota each feature by decomposing into a finite number of primitive features. The key function in the new scheme is haw to accommodate unexpected execution results. In our scheme, the too1 path plinker is designed to have a tracing capability iota the tool path execution so that a new path can be generated from the point where the operation is stopped. An illustrative example is included to show the capability of the developed algorithm.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.208-216
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• 2003

ISO 14649 (data model for STEP-NC) is a new interface scheme or language for CAD-CAM-CNC chain under established by ISO TC184 SCI. Up to this point, the new language is mainly made for milling and turning, and other processes such as EDM will be completed in the future. Upon completion, it will be used as the international standard language for e-manufacturing paradigm by replacing the old machine-level language, so called M&G code used since 1950's. With the rich information contents included in the new language, various intelligent functions can be made by the CNC as the CNC knows what-to-make and how-to-make. In particular, On-Machine Inspection required for quality assurance in the machine level, can be done based on the information of feature­based tolerance graph. Previously, On-Machine inspection has been investigated mainly for milling operation, and only a few researches were made for turning operation without addressing the data model. In this thesis, we present a feature-based on-machine inspection process by the 4 Tasks: 1) proposing a new schema for STEP-NC data model, 2) converting the conventional tolerance scheme into that of STEP-NC, 3) modifying the tolerance graph such that the tolerance can be effectively measured by the touch probe on the machine, and 4) generating collision-free tool path for actual measurement. Task 1 is required for the incorporation of the presented method in the ISO 14649, whose current version does not much include the detailed schema for tolerance. Based on the presented schema, the tolerance represented in the conventional drafting can be changed to that of STEP-NC (Task 2). A special emphasis was given to Task 3 to make the represented tolerance accurately measurable by the touch probe on the machine even if the part setup is changed. Finally, Task 4 is converting the result of Task into the motion of touch probe. The developed schema and algorithms were illustrated by several examples including that of ISO 14649 Part 12.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.3
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• pp.53-58
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• 2006

This study deals with the method of post-processing in the automatic tool path generation for 5-axis NC machining. The 5-axis NC machining cannot only cope with the manufacturing of complicated shapes, but also offers numerous advantages such as reasonable tool employment, great reduction of set-up process and so on. Thus 5-axis NC machining has been used for aircraft parts, mold and die as well as for complicated shapes such as impeller, propeller and rotor. However, most of the present CAM systems for 5-axis NC machining have limited functions in terms of tool collision, machine limits and post-processing. Especially 5-axis machine configurations are various according to the method which the rotational axes are adapted with the table and spindle. For that reason, In many cases the optimal numerical control (NC) data cannot be obtained or considerable time is consumed. To solve this problem, we applied a general post-processor for 5-axis NC machining. The validity of this post-processor should be experimentally confirmed by successfully milling to a helix shaped workpiece.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.370-374
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• 2005

This study deals with the method of post-processing in the automatic tool path generation for 5-axis NC machining. The 5-axis NC machining cannot only cope with the manufacturing of complicated shapes, but also offers numerous advantages such as reasonable tool employment, great reduction of set-up process and so on. Thus 5-axis NC machining has been used fur aircraft parts, mold and die as well as for complicated shapes such as impeller, propeller and rotor. However, most of the present CAM systems for 5-axis NC machining have limited functions in terms of tool collision, machine limits and post-processing. Especially 5-axis machine configurations are various according to the method which the rotational axes are adapted with the table and spindle. For that reason, in many cases the optimal numerical control (NC) data cannot be obtained or considerable time is consumed. To solve this problem, we applied a general post-processor fur 5-axis NC machining. The validity of this post-processor should be experimentally confirmed by successfully milling to a helix shaped workpiece.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.136-142
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• 2004

This paper deals with the design and implementation of an open architecture CNC system for Wire-EDM, with a consideration of the difference between Wire-EDM and NC cutting machines. Recent open architecture controller(OAC) related research results could be applied to directly access Wire-EDM systems at the CNC level. However, previous research about OAC is mostly aimed at NC cutting machines such as milling or lathes, and hence these results are inadequate to apply to Wire-EDM. To close the gap between previous general research on OAC and Wire-EDM specific needs, an open architecture NC model for Wire-EDM composed of a synchronization kernel and a NC functional module is proposed. Based on the control information flow and Wire-EDM specific machining process, the conceptual CNC model and the detailed implementation model for Wire-EDM is suggested.