• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.3
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• pp.258-263
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• 2011

The direction of the cutting tool plays a critical role in elliptical vibration cutting(EVC) where the cutting tool cuts workpiece in a trochoidal motion. In this study, EVC cutting device was developed using two parallel piezoelectric materials and it was observed that the rotation direction of the tool reverses as the EVC device undergoes resonance at which either flexural(cutting direction) or longitudinal( thrust direction) mode shapes occurs. To analytically explain reversal of the rotation direction, kinematic motion analysis of the tool was modified to incorporate amplification of the vibration amplitude and phase introduced by resonance. It successfully demonstrated, through Matlab simulation, reversal of the rotation direction of the cutting tool as the excitation frequency increases beyond resonance frequencies at which either flexural or longitudinal vibration occurs.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.10
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• pp.37-45
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• 2007

End-milling is intermittent cutting process performed by a tool with a number of teeth. Its cutting forces are commonly measured by the tool dynamometer which has rectangular coordinates. In this case, the pattern of cutting forces is different according to cutting conditions. At a certain cutting condition, the sign of cutting force changes from positive to negative during a revolution of one tooth. The change of force direction excites a cutting tool and severe vibration arises when radial depth of cut increases. In this study, cutting experiments and simulations were carried out in order to explain the cause of the change of the cutting force direction. In addition, the effect of the cutting force change was discussed in terms of chatter vibration in end milling.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.2
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• pp.137-143
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• 1999

The study of the high speed machining of inclined plane using ball end mill is performed. The use of ball end mill is rapidly growing in die and mold manufacturing. The cutting characteristics, such as cuttin g force, surface roughness and surface profile, are varied according to the variation of cutting directions. Free surface is cut using ball end mill, the surface profile is greatly varied depending upon the cutting direction. So this study will deal with the characteristics of cutting such as cutting efficiency according to the inclined plane of the workpiece, the cutting force according to tool path, surface profile and the roughness of surface. The optimal cutting direction to be applied the cutting for 3-D sculptured surfaces can be show through the results of this study.

• Journal of the Korea Fashion and Costume Design Association
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• v.15 no.3
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• pp.33-40
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• 2013

This paper focused on investigating the seam strength by cutting direction depending on the fabrics and weave by comparing the tensile strength and elongation of bias, warp and weft of 4 kinds of find cotton fabrics and combining 6 kinds of seam cutting directions. The cutting directions are selected the warp direction, weft direction and 45-degree bias direction. Then, three kinds of directions, the warp/warp direction, the weft/weft direction and the bias/bias directions, and the three different kinds of directions, the warp/weft direction, the warp/bias direction and the weft/bias directions, were finally selected. The results are as follows: The tensile strength of all fabrics was higher in the order of warp, bias and weft direction and tensile elongation was higher in the order of bias, warp and weft direction in almost all fabrics. 100's and 150's cotton fabrics showed the highest seam strength when they were cut in the bias/bias direction. The seam strength of the fabrics cut in the same direction was the highest in the fabrics cut in the bias/bias direction. Four kinds of fabrics demonstrated the similar seam strength. However, for the seam strength of fabrics cut in the different directions, 100's cotton fabrics had the difference of seam strength by direction and weave, but 150's cotton fabrics didn't have any difference in seam strength by direction and weave. As described above, the seam strength was influenced by the cutting direction of fabrics. Accordingly, the seam strength can be improved by changing the cutting direction of seam when making the clothing.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.1
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• pp.53-59
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• 2007

The cutting tests of wood patterns are carried out using CNC milling machine. The cutting forces are monitored to analyse the cutting process. The surface characteristics of machined surface are investigated at various cutting conditions such as cutting speed, feed speed, cutting direction of wood pattern and wood material. In the CNC end-milling, the surface roughness increases as feed speed increases and decreases as cutting speed increases. However, the cutting force and surface roughness are different along the cutting direction and material of wood pattern.

• Design & Manufacturing
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• v.17 no.2
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• pp.22-26
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• 2023

As Light-Emitting Diodes(LEDs) continue to advance in performance, their application in automotive lamps is increasing. Automotive LEDs utilize light guides not only for aesthetics but also to control light quantity and direction. Light guides employ patterns of a few hundred micrometers(㎛) to regulate the light, and the surface roughness(Ra) of these patterns can reach tens of nanometers(nm). Given that these light guides are produced through injection molding, mold processing technology with high surface quality micro-patterns is required. This study serves as a preliminary investigation into the development of high surface quality micro-pattern processing technology. It examines the surface roughness of the workpiece based on the cutting direction of the pattern and the cutting fluid type when cutting micro-patterns on STAVAX steel using cubic Boron Nitride(cBN) tools. The experiments involved machining a step-shaped micro-pattern with a height of 60 ㎛ and a pitch of 400 ㎛ in a 22×22 mm area under identical cutting conditions, with only the cutting direction and cutting fluid type being varied. The machining results of four cases were compared, encompassing two cases of cutting direction(parallel to the pattern, orthogonal to the pattern) and two cases of cutting fluid type (flood, mist). Consequently, the Ra value was found to be the highest(Ra 128.33 nm) when machining with the flood type in parallel to the pattern, while it was the lowest(Ra 95.22 nm) when machining with the mist type orthogonal to the pattern. These findings confirm that there is a difference of up to 25.8 % in the Ra value depending on the cutting direction and cutting fluid type.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.05a
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• pp.240-244
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• 1999

This paper deals with the establishment of the cutting direction on inclined plane by using ball end mill. Ball-end milling is widely used for free form surface die and mold. In these machining, the cutting parts vary because the tool tip is hemisphere shaped. The cutting characteristics, such as cutting force, surface roughness and surface profile are varied according to the variation of cutting directions. The effective tool diameter was calculated on different tilt angles and tool-path. Tool life and cutting characteristics were estimated on variation of cutting directions in the same cutting speed. In this paper, the optimal cutting direction which can be applied 3-D sculpture surface cutting is suggested.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.217-222
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• 2004

In this study, cutting slope's digital image has acquired by using video camera attached at RC helicopter. Resulted RMSE from image processing was approximately x-direction 0.27m, y-direction 0.23m and z-direction 0.35m. Application of these methods makes it convenient that acquisition of digital image about before and after the construction work of road cutting slope. Also systematical cutting slope's information acquisition will be possible by cutting slope's quantitative and qualitative analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.10a
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• pp.31-35
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• 2001

Three dimensional dynamic cutting can be postulated as an equivalent orthogonal dynamic cutting through the plane containing both the cutting vector and the chip flow velocity vector in cutting process. An analytical expression of dynamic cutting force is obtained from the cutting parameters determined by the static three dimensional cutting experiments. Particular attention is paid to the energy supplied to the vibration of the tool behind the vertical vibration and the direction. The phase lag of the horizontal vibration of the tool behind the vertical vibration and the direction angel of the fluctuating cutting force must be regarded in point of stability limits. Chatter vibration can effectively be suppressed by enlarging the dynamic rigidity of the cutting system in the vertical cutting force direction. A good agreement is found between the stability limits predicted by theory and the critical width of cut determined by experiments.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.1
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• pp.69-88
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• 2001

In the zigzag milling operation, an important issue is to design a machining strategy which minimizes the cutting time. An important variable for minimization of cutting time is the tool path length. The tool path is divided into cutting path and non-cutting path. Cutting path can be subdivided into tool path segment and step-over, and non-cutting path can be regarded as the tool retraction. We propose a new method to determine the cutting direction which minimizes the length of tool path in a convex or concave polygonal shape including islands. For the minimization of tool path length, we consider two factors such as step-over and tool retraction. Step-over is defined as the tool path length which is parallel to the boundary edges for machining area and the tool retraction is a non-cutting path for machining any remaining regions. In the determination of cutting direction, we propose a mathematical model and an algorithm which minimizes tool retraction length in complex shapes. With the proposed methods, we can generate a tool path for the minimization of cutting time in a convex or concave polygonal shapes including islands.