Abstract-This paper presents an investigation of prediction of cutting force and tool deflection in micro flat end milling. To predict cutting forces specific cutting force coefficients KT and KR were used. In fact, various cutting forces prediction models were proposed in past researches for conventional sized machining processes. However, micro end-milling processes were known as different phenomenon as respect to macro end-milling. Many past researches concerned complicated different models for micro end-milling from macro end-milling. However, cutting force models for both macro and micro end milling were fundamentally based on measured cutting forces for a series of experimental machining processes. Then, cutting force model proposed by Tlusty, which was developed for macro end-milling, was applied for micro flat end milling because this model is relatively simple. Finite element method was used to predict tool deflection based on predicted cutting forces. Predicted tool deflection amounts and actual machined profiles were compared each other in order to check out the differences between them.Index Terms-Cutting force, micro end-mill, finite element method, tool deflection.

A hot runner system can provide many advantages to plastic injection mold engineers for improving product quality. In edge gate systems in particular, the gate traces can appear on the side of products rather than the top. However, it is difficult to establish hot runner systems using edge gates because of their structural differences from conventional gate systems. This article presents the entire process of preparing a 48-cavity plastic injection molding system with edge gates. This process consists of 48-cavity injection mold design, structural analysis, verification of design plans, filling analysis of multi-cavity, cooling channel design on the basis of cooling analysis, fabrication of the mold system, and test injection. All presented computer-aided engineering analyses were conducted using ANSYS and MoldFlow.

It is very difficult to determine suitable cutting conditions in order to obtain accurate cutting profiles because machining errors caused by tool deflection depend upon cutting conditions. In this study the relationship between real cutting profiles (inclined shapes and machining errors) and cutting conditions was modeled in order to fabricate draft angle on micro molds. CCD (Central Composite Design) of DOE (Design Of Experiment) and RSM (Response Surface Method) were applied in order to model the relationship between cutting conditions and machining errors. In order to use CCD the range of radial depth of cut was chosen by 10-90㎛ and the range of feedrate was chosen by 200-300mm/min, and 9 points of cutting conditions were chosen inside determined ranges. Then, actual cutting processes were carried out as respect to 9 points of cutting conditions, draft angles and real cutting profiles were measured on cutting profiles, each response surface function was determined by conducting response surface analysis and the functions were represented by 3-dimensional graphs, contour lines and 101×101 matrices. Consequently it is possible to determine suitable cutting conditions in order to obtain arbitrary given draft angles and cutting profiles by using modeling. To validate proposed approach in this study suitable cutting conditions were determined by modeling in order to obtain arbitrary given draft angle and cutting profile, and actual cutting processes were carried out. About 95% of good agreement between predicted and measured values was obtained.