• Journal of the Korean Society for Precision Engineering
• /
• v.13 no.8
• /
• pp.164-174
• /
• 1996

As tools for machining precision componants, end mills and ball end mills are widely used. For the end mills have longer cylindrical shape comparing dianeter, they are liable to deflect when machining and induce geometrical error and deterioration of surface roughness. To improve the stiffness and the sharpness of the cutting edge of end mill, a software for manufacturing end mills are developed. The program predicts the result of helical flute grinding and the configuration of cuting edge which is located in cylindrical surface. Furthermore to facilitate the manufacturing end mills using CNC grinding machine, the setting condition which satisfy the geometrical requirements like tool rake angle and stiffness are obtained.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.8 no.4
• /
• pp.52-60
• /
• 1999

In this study the effect of roundness error with respect to the cutting conditions using the external cylindrical work piece by end mill cutting in a machining center was studied. the end mill used in this study is HSS coated with Ti-N which is of Ø 12-4 flutes. The material of workpiece is SM20C and cutting oil is used as a cooling flued The cutting experiments were carried out for the several cutting conditions(depth of cut height of end mill feed rate revolution per minute and cutting direction) and their roundness effects were compared using the least squares circle measuring method. The experimental results are summarized as follows : 1) The cutting depth is dominant for the roundness of a cylindrical work piece and the cutting speed must be determined precisely when the cutting depth is large 2) When the cutting direction in circular manufacturing is the same with the spindle rotation i.e up-cutting condition the surface roundness is also improved.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.10
• /
• pp.92-98
• /
• 2002

End mill is an essential tool to generate complex surface in workpiece and it has been developed with various materials and tool shapes. The most important factor to evaluate the performance of end mill is still the wear characteristics of flank face. In addition to the flank wear, the tool edge roughness generated by the chipping is another important factor in aspects of material property and machinability evaluation and affects the quality of machined surface. Up to now, there is no direct method for measurement of tool edge roughness. In this study, the tool edge roughness of flat end mill is indirectly measured along the axial direction of workpiece. The theoretical equation is derived in consideration of tool geometry. Finally, the optimal conditions to measure the tool edge roughness by the proposed method are presented through the theoretical review and experimental identification.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.12 no.6
• /
• pp.159-166
• /
• 2013

In order to develop the optimum shape of an MQL carbide end-mill suitable for high speed machining of wing ribs which are a detailed part of larger wing structures, using a new material Al-Li alloy, a new MQL carbide end-mill is created that has various quantities of holes, hole sizes, and hole locations. A theoretical machining graph is generated using the hammer test and FRF simulation, and a machining test is performed in order to verify the machining stability in the high speed machining area. The optimum configuration of the MQL carbide end-mill is also presented through comparing the chattering, machining noise and cutting conditions, including the maximum cutting depth, rpm, and feed rate per teeth, for each cutter.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1997.10a
• /
• pp.196-201
• /
• 1997

The biggest challenge facing today's manufacturing industry is better quality and high productivit. From an economic point of view, productivity is the most important parameter, as high productivity will reduce the cost. However, the customers of today are not only cost concerned, but also quality conscious. So high accuracy levels should also be achieved in the manufacturing process. The aim of this paper is to get a comprehensive understanding of its machinability properties and to investigate the relationship between cutting conditions and surface roughness for Ball End Mill cutting process so as to enhance its practical application.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.173-178
• /
• 1995

This paper presents a new method to obtain parameters of end-mill cutting system. For high speed milling and precision surface finish, we have to predict the deflection of tool and the critical depth of cut. The cutting system can be modeled to a vibratory system to obtain the deflection of tooll and the critical depth of cut. A new method of the modeling of one degree of freedom system was developed using bisection method, ARMA(Autoregressive Moving average) and impact test.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1998.03a
• /
• pp.25-29
• /
• 1998

One of the crucial problems that must be solved in a computerised unmanned machining environments requires the development of algorithm in order to predict the reliable cutting conditions on surface roughness. This paper is to develop the mathematical models for choosing the suitable cutting conditions and assist a comprehensive understanding of its machinability properties for cutting process by Ball End Mill. The mathematical equations developed to predict the surface results. It has been found that theoretical results obtained from the empirical equations agree with the experimental results of surface roughness.

• Journal of the Korean Society of Industry Convergence
• /
• v.4 no.4
• /
• pp.365-369
• /
• 2001

This paper presented a new model of virtualized CNC milling machine. The model verifies the over cut, the under cut and the surface roughness using NC file generated from CAM and cutting condition. The model uses Z-map model to verify workpiece. In this paper, the model used the velocities of x, y and z direction and obtained a center point of a hall end mill for modeling Z-map of workpiece. To investigate the performance of the model, simulation study was carried out. As the results, the model gave geometry accuracy of workpiece, the surface roughness and the chip loads in finish cutting that can predict tool chipping. The virtualized CNC machine can he used a flat end mill, a ball end mill and a rounded end mill.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.10a
• /
• pp.422-427
• /
• 2004

The tool geometry parameters and cutting process have complex relationships. Until now, various cutting test were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process in high speed machining. Using various tools with different geometry, relationships between tool geometry parameter (rake angle, clearance angle, length of cutter) and cutting process (cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining and to develop a software for design of end mill geometry.

• Proceedings of the Acoustical Society of Korea Conference
• /
• spring
• /
• pp.209-212
• /
• 2002

The wear process of end mill is a so complicated process that a more reliable technique is required for the monitoring and controling the tool life and its performance. This research presents a new tool wear monitoring method based on the sound signal generated on the machining. The experiment carried out continuous-side-milling for 4 cases using the high-speed steel slot drill under wet condition. The sound pressure was measured at 0.5m from the cutting zone by a dynamic microphone, and was analyzed at frequency domain. The tooth passing frequency appears as a harmonics form, and end mill wear is related with the first harmonic. It can be concluded from the result that the tool wear is correlate with the intensity of the measured sound at tooth passing frequency estimation of end mill wear using sound is possible through frequency analysis at tooth passing frequency under the given circumstances.