• 한국정밀공학회지
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• 제13권8호
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• pp.164-174
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• 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.

• 한국융합학회논문지
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• 제9권11호
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• pp.277-284
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• 2018

최근 다축 가공을 통한 정밀가공의 수요가 크게 증대되고 있다. 그러나 5축 이상의 다축 공작기계는 기하학적 관계가 복잡하여 공작기계의 기하학적 정밀도 평가와 분석이 어렵다. 본 연구에서는 먼저, 여러 가지 규정으로 분산되어 있는 KS/ISO 규격을 정리하여 다축 공작기계의 기하학적 정밀도 평가 항목을 체계화하였다. 또한, 다축 공작기계의 정밀도를 평가하고 분석하기 위해 표준공작물을 제안하였고, 표준 공작물을 사전에 정해진 방법과 절차에 따라 가공한 후, 가공면을 3차원 측정하여 분석하였다. 그 결과 표준공작물의 가공 결과와 공작기계의 정밀도가 정성적 및 정량적으로 매우 유사함을 확인하였다. 이 결과로부터 다축 공작기계의 정밀도 분석이 표준공작물의 가공만으로 가능함을 확인할 수 있었다.

• 한국정밀공학회지
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• 제12권11호
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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.

• 한국기계가공학회지
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• 제10권6호
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• pp.9-15
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• 2011

Any relative deformation between the cutting tool and the workpiece at machining point results directly in geometric and dimensional errors. The sources of relative deformations between the cutting tool and the workpiece at the contact point may be due to vibration, thermal deformation and cutting forces. In this paper, geometric error prediction of workpiece in turning has been investigated. To reach this goal, turning experiments are carried out according to selected cutting conditions. The variable cutting conditions are cutting speed, depth of cut and feed rate. The results will be useful as a guidance to select cutting conditions to improve the geometrical accuracy.

• 한국기계가공학회지
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• 제8권3호
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• pp.1-6
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• 2009

This paper presents a geometrical error compensation of tool alignment for sharp edge bite on B axis controlled machine. In precision micro patterning, bite alignment is crucial parameter for machined surface. To decrease bite alignment error, plus tilted bite from B axis center is touched to reference work piece(pin gauge) and checked the deviation from original position. Same process is repeated for maximum touch deviation value. From this touched position value, wheel alignment error in X axis and Z axis can be calculated on B axis center. Experimental results show that this compensation method is efficient to correct sharp edge bite alignment.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.227-232
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• 2002

This paper presents an algorithm for general 2D and 3D NURBS interpolation and deals with command generation for 3 axes milling machining, including the feedrate control in order to meet two limitations, a geometrical accuracy and a dynamic restriction. Both of the maximum chordal error and the maximum acceleration specified by machine parameter lead to limit the allowable feedrate on the curvature of NURBS tool path. So, motion commands at every sampling time are continuously generated by those two limitations and programmed feedrate. Simulation results of interpolating several NURBS curves show that proposed NURBS algorithm is favorable in the machining free-form curve

• 한국정밀공학회지
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• 제26권4호
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• pp.128-133
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• 2009

Focused-ion-beam (FIB) system is capable of both machining and measuring in nano-scale; hence nano-scale focusing quality is important. This paper investigates design parameters of two electrostatic lenses in order to achieve the best ion beam focusing performance. Commercial SIMION simulator is used to optimize the dimensions of the condenser and objective lenses and investigate the influence of assembly error on focusing quality The simulation results show that the beam focusing quality is not influenced by angle deviation within ${\pm}0.02\;deg$ and geometrical eccentricity within ${\pm}50$ micrometers.