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The demand for micro-end-milling for products in fields such as the medical, optical, and electronics industry is increasing. However, when machining with a small diameter end-mill (micro-end-mill) with diameters such as 0.5 mm, the rigidity of the tool itself is low; hence, the cutting conditions must be set to low values to achieve stable machining. Therefore, we examined various cutting phenomena that occur during actual machining processes to achieve high machining accuracy, high finished-surface quality, and long tool life. Some studies on micromachining achieved high accuracy, high-grade machining by considering the cutting phenomena. In previous papers, we dealt with the side-cutting phenomena in micro-end-milling of hardened die steels using a high-speed air-turbine spindle with rolling bearing. Cutting experiments were carried out by measuring the cutting force and flank wear of a cutting tool to investigate the difference in cutting phenomena caused by cutting direction in high-speed micro-end-milling. Observation of the machined surface and measurement of the profile of the cutting edge and machined surface were demonstrated. It was revealed that machining quality in high-speed up-cut milling was better than that in down-cut milling. Shoulder cutting, in which both peripheral and bottom cutting edges act simultaneously on the workpiece, was also investigated. A novel small diameter end-mill with left-hand helical tool with right-hand cut was developed to avoid damaging the cutting edge in the initial cutting stage. In the present study, high-quality shoulder cutting of a vertical wall using the new tool was proposed and demonstrated.

Bamboo grows naturally in Japan as an underutilized forest resource, and its fibers have high specific strength and stiffness, so much so that they are called natural glass fibers. In this study, a method for manufacturing a self-adhesive compact material by pressurizing and heating 100% bamboo fiber after extraction using a machining center, without losing the composition of bamboo, is proposed. This molded body is made of a 100% natural material and has a low environmental impact even when landfilled, contributing to the growth of bamboo for use as a raw material. In this study, the formation conditions for maximizing the tensile properties when forming platelets were investigated. First, an analysis of the variance was conducted using the orthogonal array test design to identify the factors affecting the objective variable and determine the contribution of each factor. In addition, estimates of the objective variable for the molding conditions were obtained from the Gaussian process regression model in a Bayesian optimization. Furthermore, as a result of comparing the maximum values of the properties of the molding conditions between the analysis of variance and the Gaussian process regression model, the values of the tensile properties were improved in the Gaussian process regression model.

The importance of micromachining using small diameter end mills and the dies used for them has been increasing in the machining of small parts. However, the reality is that there are various requirements to improve the machining surface, machining accuracy, machining efficiency, and tool life. Therefore, this paper discusses the possibility of satisfying these requirements by high-speed up cut milling in side cutting. The goal of this study was to solve the aforementioned problems, by conducting a detailed analysis of the machining phenomena in order to understand their mechanisms. In particular, the effects of high-speed cutting using a high-speed air-turbine spindle with highly stiff rolling bearings were analyzed. Moreover, cutting experiments were conducted by measuring the cutting force and flank wear of the tool, to reveal the differences in the cutting phenomena relative to the cutting direction in high-speed micro end milling. Description of the machined surface and the measurement of its profile were also included in the discussions. On the basis of the results, high-speed up cut milling is a better choice than down cut milling, furthermore, a high-feed rate further increases machining efficiency and improves tool life.

In small and precision die and mold making, small-diameter end mills are often used through rough to finish machining processes. However, higher-efficiency machining technology in die and mold manu...

Currently, carbon fiber reinforced plastics (CFRP) are being increasingly adopted in various fields. Thus, machining CFRP with high accuracy and high efficiency is required. In addition, machining stack materials composed of CFRP and titanium alloys is required. Therefore, in this study, a novel end-mill electroplated with a cubic boron nitride (cBN) abrasive, which has high thermal resistance, is proposed. In order to evaluate the influence of the base metal shape of the proposed end-mill on the machining process, several cBN-electroplated end-mills with different rake angles or chamfers were fabricated and used to cut CFRP. In addition, in order to evaluate the abrasive shape, a blocky abrasive was also electroplated on the end-mill. The results indicate that the negative rake angle is useful to restrain the progression of tool wear. However, in order to obtain the element of cutting and grinding, it is required that the rake angle should be positive. Moreover, the reasonable width of chamfer is effective for restraining the increase in CFRP temperature. Further, a sharp shaped abrasive can more effectively generate a CFRP with a sharp edge compared with a blocky shape abrasive.

A natural resource, bamboo, is widely distributed in Asia. Bamboo grows faster than other renewable natural material. Further, bamboo fibre has high specific strength and stiffness. We draw attention to this bamboo as a sustainable and environmentally superior material. We propose a sustainable manufacturing system using bamboo. A self-adhesive fibreboard has been fabricated by end-milling and hot press forming. This paper describes the environmental evaluation of this system using life cycle assessment.

Research is currently ongoing for composite materials using natural fiber with a small burden on the environment. We have been focusing on bamboo because of its fast growth, renewability, flexibility, low cost, and high specific strength. We previously proposed a novel hot press fabrication method for binder-free green composite products made from bamboo fibers extracted by end-milling with a machining center. We can use this method to form three-dimensionally shaped products, especially hemispherical shells, by using two kinds of dies. However, this method is complex and takes longer than one-step hot press forming. In the present report, we propose a new method that uses bamboo powder with a particle size of less than 500 μm. Our new method uses one-step hot press forming and is quicker than the previous method at making a hemispherical shell shape. The new method was successfully used to manufacture hemispherical shell-shape products.

Since demands for Carbon Fiber Reinforced Plastics (CFRP) are increasing, the number of the studies on machining of CFRP is also increasing. However, since there are already reports on a trimming of a surplus portion or a drilling, we focus on a face machining and a generating the step shape with several cutting tools. Problems in the machining of CFRP include an occurrence of the burr and delamination. Therefore, in this report, we investigate these problems in face milling. And, the machining behavior (Cutting temperature, Cutting force) during the machining is estimated.

Nowadays, resource saving technologies have become important because of increasing global environmental problems. Moreover, demand is increasing for the manufacturing and machining of small mechanical parts because of the downsizing of electronic mobile devices. Thus, one requirement has emerged that these small parts have to be fabricated by smaller machine tools to reduce the environmental burden. Here, when we look at the heat treatment process, it is found that most small parts are generally treated with a large size furnace as well. Therefore, we focus on compact machine tools to develop the clean and energy-saving technology in the manufacturing fields. In the present report, we consider an in-situ laser heat treatment technology integrated on the table used for compact machine tools. In particular, we perform the entire laser hardening of a small thin plate with a small power semiconductor laser, which is an attempt to harden a whole steel sheet. However, thin plates deform during the laser hardening process, which is called “laser forming.” Thus, we discuss an effective irradiation path to prevent the deformation of plates while quenching the entire plate. Moreover, considering the power consumption in the laser quenching process, we investigate an appropriate laser irradiation condition.

Bamboo grows faster than other renewable natural materials. Bamboo fiber, in particular, has attracted attention as an environmentally superior material. Therefore, we propose a sustainable manufacturing system using bamboo. A method is also proposed for extracting bamboo fibers end-milled using a machining center with in-situ measurement. Bamboo fibers with highly precise shapes are efficiently acquired. Previously, we proposed the fabrication of a binder-free composite by a hot press forming method that only uses bamboo fibers extracted by a machining center. We experimentally demonstrated various hot press forming conditions and achieved proper ones to optimize the forming process. However, we have not yet constructed a method to obtain the best fiber extracting and molding conditions considering both its efficiency and performance. Therefore, in this report, we investigate the influence of the length of used bamboo fiber on the characteristics of the molded products, as its length deeply affects the extracting efficiency and focuses on a degradable plastic as a standard of molded product strength.

Recently, with regard to global warming energy shortage, the saving energy has become a global issue. The demand for variety, variable production, high speed, high accuracy, and complex processing in the manufacturing fields has been emerged. Furthermore, automatic extinction of computer numerical control (CNC) screens and automatically hold of oil pressure pump in idling has been raise to do on research. On the contrary, there are few reports dealing with reducing power consumption based on existing machining tools system. The method presented in this report can be applied to various size and weight of machining tools. The experimental result of standby power and minimum power with emergency stop circuit of various machining tools is discussed in this research work. To expand the stage of the proposed method, a brand new system is developed. As a result, power consumption of a machining tool with the phase of idling can be effectively reduced through emergency stop circuit. By activating emergency stop circuit, power consumption can be equalized with the condition of main power-ON only. The standby electric power increases along with increasing weight of machining tools. Through the proposed original system, it is possible to set switching of servo ON and OFF to each section. Consequently, the methodology would be applied into many fields of precision processing.

Non-uniformly shaped workpieces made of such materials as ceramic and cast metal can prevent higherefficiency machining from being achieved in the conventional process due to large deviation of removal stock. Therefore, this paper proposes a novel method to achieve a high-efficiency machining strategy for non-uniformly shaped workpieces using on-machine measurement. This method utilizes on-machine measurement of a workpiece placed at an arbitrary position on a machine table as a machining pre-process. The product shape is arranged in the workpiece shape, and NC program for machining is generated based on the on-machine measurement data. The proposed method can be expected to be reasonable for a largesize product that requires long machining time because of long initial setup time and air-cutting in machining. A case study using numerical experiment was carried out. The results showed that our proposed method reduced total manufacturing time including on-machine measurement.

This paper describes fabrication of a magic-mirror with an extremely small concavo-convex surface, which is invisible to the naked eye. The magic-mirror was manufactured by end-milling with a machining center on the rear of the workpiece after polishing. Incident light was radiated to the mirror surface and the reflected light was projected on a screen. The tool pass by CNC programming show up as image of magic-mirror on the screen. Analysis of the image on the screen indicated completion rate of magic-mirror surface generation. As some experimental result, the integrated magic-mirror production process on the machining center could be achieved by a novel application of on-machine magnetic abrasive finishing and ball end-milling. Moreover, it was found to possible to fabricate a magic-mirror with satiny and continuous-curvature corrugated surface.

Demand is increasing for the manufacturing and machining of small mechanical parts. We focus on using a multi-functional desktop-sized machine tool to meet such demands because power consumption is decreased when they are machined. However, few reports have focused on heat treatment among manufacturing processes, we investigate the laser heat treatment of small parts as a highly efficient and eco-friendly method and propose in-situ heat treatment on a desktop-sized machine tool using a low-power diode laser beam. We quenched a small thin steel plate with a 30 W diode laser source. Our proposed method makes it feasible to quench a small thin steel plate and effectively reduces the power consumption of in-situ heat treatment by a desktop-sized machine tool.

Machining is often performed by a machining center using various cutting tools and conditions for different shapes and materials. Recent improvements in CAM system make it easier for even unskilled engineers to generate NC programs. In the NC program, the end-milling conditions are decided by engineers. However, engineers need to decide the order of the process, cutting tool selection, and the end-milling conditions on the basis of their expertise and background knowledge because the CAM system cannot automatically decide. Data-mining methods were used to support decisions about end-milling conditions. Our aim was to extract new knowledge by applying data-mining techniques to a tool catalog. We used both hierarchical and non-hierarchical clustering of catalog data and also used applied multiple regression analysis. We focused on the shape element of catalog data and we visually grouped ball end-mills from the viewpoint of tool shape, which here meant the ratio of dimensions, by using the k-means method. We also found an expression for calculating end-milling conditions, and we compared the calculated with the catalog values.

Bamboo grows faster than other renewable natural materials. Bamboo fibre, in particular, has attracted attention as an environmentally superior material. Therefore, we proposed a sustainable manufacturing system using bamboo. An extraction method of bamboo fibres end-milled using a machining centre with in-situ measurement was also proposed. Bamboo fibres with high precision shapes are efficiently acquired. Previously, we proposed the fabrication of binder-free composite by a hot press forming method that only uses bamboo fibres extracted by a machining centre. We experimentally demonstrated various hot press forming conditions and achieved proper ones to optimize the forming process. However, when the environment changes, the characteristics of the binder-free composite are not known. If we want to use the binder-free composite, we have to know how much it is affected by the external environment for use as a mechanical object. Therefore, we investigated the changes of the characteristics at high temperature and high humidity.

In recent years, studies have been conducted about creating metal moulds using a five-axis controlled machining centre with ball end milling. Most of these reports concern the programming of CAM based on geometry. However, there have been few reports related to polish-less finished surface. Furthermore, a specular surface like a mirror and finishing under a constant angle between ball end milling and the work piece have not been investigated. Therefore, this paper deals with the gloss of the machined surface when feed rate and pick-feed rate are changed to maintain constant surface roughness considering tool run-out under the condition that the angle between the tool and work piece in contact are inclined at 15. However, by changing the combination of feed rate and pick-feed rate, various specular changes and direction of disposition of reflected light were obtained. Therefore, we suggest a new method of evaluating the gloss of these finished surfaces. Comparing results by the proposed method with ones by a glossmeter, it is clear that an appropriate ratio of feed rate and pick-feed rate is important for obtaining finished surface. Moreover, it is demonstrated that the proposed method is effective for estimating the gloss of the machined surface.

In recent years, sustainable materials using natural resources have been developed to alleviate environmental problems. Bamboo has especially drawn attention because it has the fastest growth rate among various natural materials, and its fiber also has high specific strength and stiffness like glass fiber. Previously we proposed a high quality bamboo fiber extraction method with a machining center that overcame issues including lower shape accuracy and inefficiency caused by conventional extraction methods. In this paper, we implemented a fabrication of self-adhesive products using only bamboo fibers extracted with a machining center. Moreover, mechanical properties such as Young's modules and tensile strength of the product were investigated. In addition dumping characteristics were also studied. Influences of moisture rate of the products on the properties were evaluated by concerning a practical use. Finally, possibility of the product for bamboo fiber recycling in order to reduce environmental burdens in manufacturing phase was also addressed. As a result, it was found that the self-adhesive products using only bamboo fibers show some reasonable performances.

The uses of data mining methods to support workers decide on reasonable cutting conditions has been investigated in this work. The aim of our research is to find new knowledge by applying data mining techniques to a tool catalog. Hierarchical and non-hierarchical clustering of catalog data as well as multiple regression analysis was used. The K-means method was used and on the shape presented in the catalog data and grouped end mills from the viewpoint of the tool's shape, which here means the ratio of dimensions has been focused. The numbers of variables were decreased using hierarchical cluster analysis. In addition, an expression for calculating the better cutting conditions was found and the calculated values were compared with the catalog values. There were three cutting conditions: conditions recommended in the catalog, conditions derived by data mining, and proven cutting conditions for die machining (rough processing).

The purpose of the present study is to apply data-mining methods to support the decision of reasonable cutting conditions. Although an enormous amount of information is listed in a catalog, it is not possible to know all of it. Seen from the viewpoint of the user, this enormous amount of information becomes a hindrance. For example, even if an expert worker does not look at a catalog, in end-mill processing, he can decide the appropriate processing condition efficiently from experience; however, this type of situation creates difficult problems for an unskilled worker or a skilled worker with little experience. The recommended cutting condition for every type of material is listed in a catalog together with the appropriate tool, but it takes much time and labor to search and examine the catalog to find the right tool, and this process is inefficient. The main subject of our research was to support the processing condition of the end-mill for each precision tool efficiently based on end-mill clusters. Our research applied the techniques of data mining, in particular, non-hierarchy clustering and hierarchy clustering, to catalog data. With these techniques, we applied multiple regression analysis and reached the following main conclusions. As a first step, we paid attention to the shape element of catalog data. In addition to using conventional mining processes, we grouped end-mills from the viewpoint of tool shape, which meant the ratio of dimensions, visually by applying the K-means method. We applied variable cluster analysis next to each cluster and extracted an predictor variable to represent each cluster, and we performed multiple regression analysis and derived a cutting condition decision formula. The cutting condition decision formula provided high accuracy. The accuracy was higher than the results achieved through mining of all data. A more highly precise processing condition decision formula was derived by doing mining again, excluding the peculiar data clusters such as small diameter end-mill. We understood what was effective for cutting condition decision to be factors related to blade length and the ratio of the full length, factors which have not been singled out through background knowledge or expert knowledge, but were noticed as an effect of catalog mining.

Bamboo grows faster than other renewable natural materials. Bamboo fiber, in particular, has attracted attention as an environmentally superior material. Therefore, we proposed a sustainable manufacturing system using bamboo. An extraction method of bamboo fibers end-milled using a machining center with in-situ measurement is proposed. Bamboo fibers with high precision shape are efficiently acquired. In the present report, we propose the fabrication of binder-free composite by a hot press forming method that only uses bamboo fibers extracted by a machining center. We experimentally demonstrated various hot press forming conditions and achieved proper forming conditions to optimize the forming process. We also made various three-dimensional shapes considering the practical applications of the formed binder-free bamboo fiber moldings.

This paper describes the laser hardening of micro-cutting edges using an on-machine heat treatment system with a YAG laser. Various laser conditions were evaluated to perform laser quenching on a machine tool without melting at the edges. We also investigated the influence of the motion accuracy of the machining center on the quenching characteristic of micro-cutting edges after laser irradiation. We clarified that we could quench both the straight and curved corner parts by arranging proper laser irradiation conditions considering the motion accuracy of the machining center.

This study describes the programming of cutter location based on a constant feed-speed vector at the cutting point with a ball nose end-mill tool by a Five-axis Machining Center. In the present paper, we proposed a new programming method to maintain both feed-speed amplitude and direction at the cutting point using rotational and linear axes controlling. First of all, we focused on generating a hemispherical surface with a ball nose end-mill, and investigated its surface roughness and its profile error. As a result, it can be seen that this method is effective to obtain a fine machined surface roughness and to avoid the influence of linear motion errors on the machined profile at the normal direction to the feed-speed vector.

This paper deals with a decision method of cutting conditions and tool life estimation method for end-milling processes of plain carbon steel. Basic cutting conditions for side cutting of a step, one of the most basic milling processes, are chosen from the database given by a cutting tool manufacturer. These data are transformed for individual milling processes, e.g. trochoidal grooving, spiral hole enlarging, and corner milling, such that constant cutting force is kept by using feedforward control. Cutting tests were conducted for the workpiece composed of various cutting features, and it was clarified that adequate cutting conditions and adequate tool life are simply decided using by this method.

This study describes the machining of the fine surfaces with a ball nose end-mill tool by a five-axis controlled machining center. In the present paper, we demonstrate that it is effective to maintain a constant contact angle between an end-mill ball nose and a work surface in machining in order to obtain the fine machined surface because this makes it possible to avoid an irregular luster (striped pattern) caused by a profile error of the ball nose on the machined surface. Moreover, it can be seen that the surface roughness (i.e., convexities and concavities) along the tool feed direction can not be overlooked in trying to obtain the fine machined surface such as a mirror surface. As a result, a new method is proposed to determine the optimum cutting condition to achieve the minimum cutting time considering the surface roughness along the pick direction and the feed direction under a constant surface roughness.

Recently, materials made of natural resources have been gaining attention. In particular, high expectations are placed on bamboo fiber. However, conventional bamboo fiber extraction techniques have problems, primarily involving quality, accuracy, and efficiency. To solve these problems, a new method of obtaining bamboo fibers with a machining center (MC) is proposed. NC programs are designed according to a cutting theory based on a geometrical tool path for cylindrical work. The experimental results verify that fiber shape can be controlled by adjusting the appropriate end-milling conditions with a spiral tool path. The fiber length is influenced by the axial depth of the cut, while the fiber diameter is influenced by the vascular bundle size, which is a component of bamboo. Therefore, considering the direction and size of the bamboo components, the desired bamboo fibers can be obtained with high quality and accuracy using end-milling with an MC.

This paper describes a CAM system of drilling for Printed Wiring Boards (PWBs). We focused on drilled hole wall quality in addition to machining efficiency. The drill and PWB temperature in drilling was monitored using thermography, because the temperature had a relation to surface roughness of drilled hole wall. The various tool paths were evaluated in order to improve drilling efficiency with sufficient hole quality. As a results, we could have a suggestion of tool path for good quality of drilled hole wall.

This paper describes on high accuracy contour grinding. We focused on problems in the current CAM systems in order to improve the machining accuracy and the quality of ground surface. The changes of curvature in workpiece profile were attracted attention because the ground workpiece profile changes with tool path and grinding force. Therefore, the grinding tests with monitoring the grinding force were carried out for three type models with different variety of curvature. The workpiece profile after grinding was evaluated by reflected light images test. As a result, considering the responsibility of machine tool, it was clarified that the smooth-continuation model shows the best quality of ground surface.

This study describes to finish the curved surfaces in hardened steels (JIS: SKD11, etc.) with (Al, Ti) N-coated ball nose end-mill. Two kinds of cutter locations are used; scanning line cutting and contour line cutting, for finishing the curved surface of hardened steel. In the present paper, the cylindrical surfaces machined by a ball nose end-mill are investigated. As a result, in scanning line machining, an irregular luster (striped pattern) peculiar to the machining work surface was caused by a profile error of ball nose. In addition, a new method was also proposed to estimate the peculiar striped pattern which could be judged from observation of the machined surface using Makyoh-topographic images.

Recently It is difficult to maintain the high surface quality ingenerating curved surface shape under five-axis controlled end-milling. In this study, we aimed at maintaining feed speed vector at milling point by controlling two linear axes and a rotary axis with a five-axis machining center, to improve machined surface quality and suggested a method for solving shape error of machined workpiece considering differences of three axes’s sarvo characteristics. As the results, it could be seen that shape error greatly decreased based on the proposed method.Copyright © 2015 by ASME

Carbon fiber reinforced plastic (CFRP) was developed in the 1960s. Since then, it has been used in various fields. Accordingly, the number of studies related to machining of CFRP has been increasing (e.g. cutting, laser processing, or abrasive water jet machining). However, these studies have been focusing on the trimming of surplus portions or drilling. In addition, the degradation of mechanical properties due to the heat induced during machining has not been sufficiently considered. Furthermore, another issue is the cost involved, such as tool and equipment costs. This makes several of these proposed methods tremendously expensive. Therefore, in this study, electroplated end-mills with electrodeposited cBN or diamond grains of different grit sizes (the mesh size are #600, #1000, #1500 and #2000) are fabricated. As a result, the cost of the electroplated tool will decrease by 2/3 compared to general diamond-coated tools. Moreover, the flat cutting of CFRP is often carried out with these fabricated tools and with general diamond-coated tools. In cases where the fabricated tools are used, the machined CFRP products are burr-free or nap-free. Additionally, the induced CFRP temperature during cutting decreases compared to the case of diamond-coated tools. From these results, the optimum grit size was determined to be #1000. On the other hand, end-mills with deposited cBN or diamond grains, fixed on the tip of the fabricated tool, occasionally dropped out after a few paths. Therefore, efforts are presented to improve the tool tip shape and minimize its grain dropout rate. Based on such improved characteristics, the electrodeposited end-mill is expected to be able to machine CFRP more effectively.Copyright © 2015 by ASME

We previously proposed data-mining system to derive useful information from the data and attempt to determine the ball-nose end-milling conditions in a rapid prototype manufacturing system. Practical end-milling condition decision equations are derived to determine the end-milling conditions at each cluster by using response surface method. End-millings of hardened die steel JIS SKD61 (HRC53) and DH31S were carried out to investigate the practicability of derived mining conditions under contour line milling. As a result, our catalog-mining system was found to be effective in selecting the end-milling conditions as the first trial condition. Catalog mining can derive indicative cutting conditions for unskilled engineers.Copyright © 2014 by ASME

Recently, a novel manufacturing technology has spread out with a five-axis machining center. It is especially important to keep the surface roughness on an entire machined surface constant. Thus, we proposed a novel method for maintaining a constant feed speed vector at the cutting point between the end-mill tool and the workpiece surface by controlling two linear axes and a rotary axis with a five-axis machining center. In the present report, we focused on machining the combined inner and outer radius curvature and investigating the influence of synchronous control error between the linear axes and rotary axis on the machining accuracy and surface roughness. As a result, we determined that it is possible to suppress sudden change in the synchronous motion error by accurately aligning the motion direction of the linear and rotary axes and the feed speed vector at milling point at the contact point of the inner and outer circles.Copyright © 2013 by ASME