• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.5
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• pp.100-105
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• 2002

The comprehensive system analysis for contour milling operation and its error has performed in this study. The obtained experimental results were from the practical points of view. In down-milling operation the contour error curve illustrates bigger thean actual workpiece radius. The contour error increased when the cutter loads increased. Through the procedural evaluation, it could ascertain the characteristics of generation mechanics in circular contour machining error, and the weight of each factors.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1522-1525
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• 2007

Circular milling operations are used to enlarge die and cylinder bores, and machine airframe pockets. In this case, cutting force varies as cutting tool position relative to workpiece. This paper presents a mechanistic model of geometric uncut chip thickness by predicting time varying cutter-part intersection as the cutter travels along the circular path. Compared with experimental results, the suggested cutting force model shows a good agreement.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.6
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• pp.83-89
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• 1999

This paper presents the in-process runout compensation methodology to improve the surface quality of circular contouring cut in end milling process. The runout compensation system is based on the manipulation of workpiece position relative to cutter in minimizing the cutting force oscillation at spindle frequency. the basic concept of this approach is realized on a end milling machine whose machining table accommodates a set of orthogonal translators perpendicular to the spindle axis. The system performed that measuring the runout related cutting force component, formulating PI controlling commands, and the manipulating the workpiece position to counteract the variation of chip load during the circular contouring cut. To evaluate the runout compensation system performance, experimental study based on the implementation of two-axes PI force control is presented in the context of cutting force regulation and part surface finish improvement.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.7
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• pp.98-104
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• 2022

Circular sawing and milling are general machining processes used for routing fiber-reinforced plastics (FRP). In this study, the productivity and cutting quality of a circular saw and flat endmill were compared. As a result, the productivity of the circular saw was approximately ten times higher than that of the endmill for the same tool life, and the burr size of the circular saw was 14 times smaller than that of the flat-end mill. The spectrogram analysis of the cutting sound also showed that the acoustic emission of the circular saw was more uniform than that of the flat end mill. Circular sawing is thus a more suitable process for the straight cutting of pultrusion FRP than a flat endmill.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.11
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• pp.197-203
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• 1999

Increasing demands on precision machining have necessitated the tool to move not only position error as small as possible, but also with smoothly varying feedrates. Because of the lack of accurate and efficient algorithms for generation of 3-dimensional lines and circles, a full accomlishment for available machine tool resolution is generally unavailable. In this paper, a reference-pulse type 3-axis PC_NC milling system is developed for the precision machining of complex shapes in 3-dimensional space. Three AC servomotors are used as the actuator instead of the hand wheel to operate a 3-axis milling machine under the same mechanical structure. A PC is used to handle the control signal calculation for various types of motion command. To achieve the synchronous 3-axis motion, a real-time reference-pulse 3-dimensional linear and circular interpolator based on the intersection criteria is developed in software. The performance test via computer simulation and actual machining have shown that the PC-NC milling system is useful for the machining of arbitrary lines and circles in 3-dimensional space.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.1 s.178
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• pp.201-208
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• 2006

Recently, there are many studies for the micro-machining using Piezo actuator. However, because of its step-by-step motion, it is nearly impossible to increase the machining accuracy for a circular path. To increase the accuracy, it is well known that it is necessary the finer and synchronous movement for x-y axes. Therefore, this paper proposes an adaptive control for finer movement of the actuator, and realizes a synchronous control for the x-y axes. The experimental results show that the machining accuracy is remarkably improved.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.446-452
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• 2005

Recently, there are many studies for the micro-machining using Piezo actuator. However, because of its step by step motion, it is nearly impossible to increase the machining accuracy for a circular path. To increase the accuracy, it is well known that it is necessary the finer and synchronous movement for x-y axes. Therefore, this paper proposes a voltage control for finer movement of the actuator, and realizes a synchronous control for the x-y axes. The experimental results show that the machining accuracy is remarkably improved.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.543-550
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• 2005

Recently, there are many studies for the micro-machining using Piezo actuator. However, because of its step by step motion, it is nearly impossible to increase the machining accuracy for a circular path. To increase the accuracy, it is well known that it is necessary the finer and synchronous movement for x-y axes. Therefore, this paper proposes an adaptive control for finer movement of the actuator, and realizes a synchronous control for the x-y axes. The experimental results show that the machining accuracy is remarkably improved.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1054-1058
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• 1995

There have been many research works for the indirect cutting force measurement in machining process, which deal with the case of one-axis cutting process. In multi-axis cutting process, the main difficulties to estimate the cutting forces occur when the feed direction is reversed. This paper presents the indirect cutting force measurement method in contour NC milling processes by using current signals of servo motors. An artificial neural network (ANN) system are suggested. An artificial neural network(ANN) system is also implemented with a training set of experimental cutting data to measure cutting force indirectly. The input variables of the ANN system are the motor currents and the feedrates of x and y-axis servo motors, and output variable is the cutting force of each axis. A series of experimental works on the circular interpolated contour milling process with the path of a complete circle has been performed. It is concluded that by comparing the ANN system with a dynamometer measuring cutting force directil, the ANN system has a good performance.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.11
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• pp.45-51
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• 1995

In order to suggest the proper cutting conditons of the CNC milling machining for the free-form surface, some experments were carried out. In the experiments, the influence of cutting conditions on a inclined spherical surface were examined by geometrical analysis. In this study, the roundness and cutting force were measured to know the effect of several cutting conditions on the machined surface and the cutting characteristics were carefully investigated. The results obtained in this study are aw follows. 1) If the tool ha s enough rigidity, we can get better dimensional accuracy in up-ward cutting than down- ward cutting. 2) A great roundness error is appeared on the surface declined under 30 degress to the horizontal plane in circular machining by a bal end mill. 3) If the thrust force is increased, the stability of tool is decreased. And the phenomenon is apperared in great in down-ward cutting than up-ward cutting.