Ball-end Cutter Research Articles

Study on Parameters Measurement System of Ball-End Cutter Based on Optical Vision Detection

In manufacturing field, the geometric parameters measurement of tool is an essential process in manufacturing ball-end cutter. An optical visual inspection system of ball-end cutter parameters was studied through designing CCD camera, optical microscope, image grabbing card, visual light and 3D detection tables. Through the grabbing and processing image information of ball-end cutter, visual inspection method was applied to measure parameters of ball-end cutter. Some algorithms including the gray scale processing, median filtering, edge detection and least square fitting method of measured data were analyzed to develop image processing and tool detection software of ball-end cutter. The reliability and accuracy of this detection system were verified through the practical test.

Tool Path Generation for Clean-up Machining of Impeller by Point-searching Based Method

Machining quality of clean-up region has a strong influence on the performances of the impeller. In order to plan clean-up tool paths rapidly and obtain good finish surface quality, an efficient and robust tool path generation method is presented, which employs an approach based on point-searching. The clean-up machining mentioned in this paper is pencil-cut and multilayer fillet-cut for a free-form model with a ball-end cutter. For pencil-cut, the cutter center position can be determined via judging whether it satisfies the distance requirement. After the searching direction and the tracing direction have been determined, by employing the point-searching algorithm with the idea of dichotomy, all the cutter contact (CC) points and cutter location (CL) points can be found and the clean-up boundaries can also be defined rapidly. Then the tool path is generated. Based on the main concept of pencil-cut, a multilayer fillet-cut method is proposed, which utilizes a ball-end cutter with its radius less than the design radius of clean-up region. Using a sequence of intermediate virtual cutters to divide the clean-up region into several layers and given a cusp-height tolerance for the final layer, then the tool paths for all layers are calculated. Finally, computer implementation is also presented in this paper, and the result shows that the proposed method is feasible.

An efficient method for NC machining of sculptured surfaces

This paper presents a robust method to decompose a sculptured surface into convex and non-convex regions with specific range of curvature. This method provides important tools for tool path generation and cutter size selection for NC machining of sculptured surfaces. Convex regions can be machined efficiently with a large ball-end cutter. Non-convex regions can be milled using a smaller ball-end cutter to avoid gouging. The tool paths are the intersection curves between parallel planes and the sculptured surface. The values of the step length and the path interval are calculated based on the machining tolerance requirements. After detecting and eliminating the tool interference, the interference-free tool path is generated. The effectiveness of the developed algorithm is demonstrated through simulation and actual cutting tests.

Physical Field Evaluation Model of High Speed Ball-End Milling Hardened Steel

Based on the experiment of high speed ball-end milling hardened steel, investigated the distribution characteristics of cutting force and cutting heat and wearing character of cutter, and set up analysis model of cutter physical field. Using failure criterion and safety margin of cutter, founded physical field evaluation model of high speed ball-end milling cutter. By means of physical field analysis and experiment, explored the influence of cutting parameters on cutting property during cutter wear. Results indicate that the method of safety margin and physical field evaluation model can evaluate cutting property of cutter effectively, the impact of feed per tooth on physical field and safety margin is noticeable, and high speed and small feed are helpful to improve safety margin and cutting performance of cutter.

Free Surface Processing Parameters such as the Curvature Analysis

In order to improve the free surface machining accuracy and processing efficiency, this paper proposes a processing parameters such as free surface method, through to the free surface parts for the parameters such as the curvature analysis, and then get free surface modeling geometry characteristic change rule, choose reasonable parameters optimization cutting knife, a path, the improvement of the machining accuracy and processing efficiency. We introduce the conception of curvature to analyze the curvature and optimize the cutting parameter and cutting tool parameter to avoid interference phenomena happening and improve the processing efficiency and precision. Take the ball end cutter for example to process simulation, it shows that through the analysis of the free surface curvature method to avoid the intervention process is feasible, and has been verified by the experiment.

Research on Machining Ellipse Gyre Surface with the Ball-End Cutter

Ellipse gyre surface has wide application due to its special optical property. High-precision manufacturing is more and more important. Here we performed an analysis to decreasing reduction of batch production cost. Firstly, the scheme of manufacturing of 2-axis NC machining is given. Secondly, a basis for calculation of row space with the ball-end cutter is provided. Lastly, the formula of the level and the axis feed is also provided. The feasibility and reliability of these models are proved with examples.

Research for NC Milling Error Analysis and Compensation

Aiming at NC milling processing error problem, ball-end milling cutter is taken as researching object, its the stressed deformation, heated deformation, tool wear and workpieces’ heated deformation are modeled. The milling comprehensive error at all coordinate directions are obtained with superposition method. Corresponding error prediction and compensation scheme are put forward, and milling error models are tested and verified through experiments, thus to make try cutting cost reduce and processing efficiency improve, to lay the foundation for NC milling machining simulation system improvement.

Modeling and Simulation of Milling Forces for Ball-End Cutter with Considering Comprehensive Factors

In this paper, influence mechanism of variously physical factors for milling force in any feed direction is studied during the milling process. Firstly, the effects of spindle eccentricity, cutter deflection and cutter vibration for the instantaneously undeformed cutting thickness are analyzed, and the mathematical expressions of chip thickness is set up. Then,on this basis of cutting force and chip load, the milling force model of ball-end mill with considering integrated physical factors is established though the differential method, and a simulation system for prediction of milling forces during the milling process is developed. This milling force model is verified through simulation and analysis of milling forces.

Machining of Free-Form Surface Method and Implementation Research with Ball-End Cutter

A new tool path generation method based on Z-buffer method is proposed for free-form surface machining by using ball-end cutters. Firstly, to avoid ball-end mill cutting the workpiece, we make the cutter shaft which is perpendicular to machining surface tilt angle θ, then determine the examining area and then judge there is or not a interference occurring between ball-end mill and examining area, if there is, then make a adjustment for cutter shaft. The discretized points within the examining area are efficiently read in and stored directly by the computer hardware; no extra searching and iterative methods are needed. Simulation results show that, comparing with the traditional algorithm, the tool-position calculation time is shorter, and the phenomenon of workpiece squeezed and scratched is less in this algorithm. It meets the basic needs of five axis machining accuracy. Finally we make a practical machining experiment for cutter location generated.

The Analysis of Effects of Curvature Attribute on Interference in Freeform Surface Blade NC Machining

This paper proposes the Gaussian Curvature by analyzing the free surface of the blade surface curvature, which is based on the Gaussian Curvature parameter mapping method to study the Gaussian curvature of free surface NC machining process interference. We introduce the conception of curvature to analyze the curvature and optimize the cutting parameter and cutting tool parameter to avoid interference phenomena happening and improve the processing efficiency and precision. Take the ball end cutter for example to process simulation, it shows that through the analysis of the free surface curvature method to avoid the intervention process is feasible, and has been verified by the experiment.

Optimization of Axis Tilt Machining with Five-Axis Ball-End Cutter

A half of covering angle processing method is proposed for optimizing process efficiency and quality with ball-end tool axis tilt. Firstly, according to the features of ball-end tool structural, this paper introduced traditional no-tilt processing problems, such as tool fast wear and poor processing quality, and then verified the effect of tool tilt processing by analyzing and comparing cutting quality with the differences of the no-tilt processing and tilt processing. Finally, it introduced two optimization methods about tool tilt processing, and also made a comparison with its feature. The results show that traditional processing brings about more extrusion and scratches, while little and high efficiency with method of tool tilt processing. Conclusion: it not only brings higher processing quality and efficiency, but also can make the ball-end cutter be longevity of service.

Tool Wear Measurement of Ball-End Cutter Based on Shape Mapping

In milling process, tool wear has important influence on product machining quality. A measuring method for tool wear of ball-end cutter is proposed in order to predict effectively tool wear. The measuring method maps tool wear shape on a block of metal material by milling hole mode after finishing each milling experiment. These formed holes are measured on CMM (coordinate measure machine) by using the planned measuring method. The measuring process is established to attain tool wear of ball-end cutter. The experiments results show that the proposed measuring method can effectively attain tool wear to provide a foundation for tool wear modeling and monitoring.

A HIGHER FIDELITY MODELING OF THE CUTTING EDGE OF BALL-END MILLING TOOL

Ball-end milling tools have been widely used in machining of complex freeform surfaces. The precision and efficiency of ball-end milling process can be improved by an accurate modeling of the tools, the tools' paths and the machining conditions. However, only rough geometric models have been applied so far, which do not consider the machining conditions and the physical changes. To achieve the best results, an accurate modeling of the cutting edge and the physical behavior of the entire cutter is needed. This paper proposes an articulated model that enumerates both the geometric characteristics and the physical effects acting on the cutting edge-segment of a ball-end milling cutter. The model considers the deformations caused by the milling forces, vibration, spindle eccentricity, together with thermal deformation and wear of the cutter. The mathematical description of the behavior has been transferred into a computational model. The pilot implementation has been tested in a practical application. The first findings show that the proposed theoretical model and implementation provide sufficiently precise information about the behavior of the cutter in virtual simulations; hence it can be the basis of a fully fledged and more efficient planning of milling processes.

The Research of High Speed Machining Technology for Sub-Regional Complex Surfaces Based on Feature

The high speed machining technology of complex surface has been a focus of the study. Based on the analysis of cutting force model for ball-end cutters and cutting force tests of 3-axis machining, the paper brings forward the reasonable oblique angle of tool axis for complex surface with different curvature. According to the different feature of surface shape, the surface is classified in terms of oblique angle formed by tool axis and normal vector of surface. Meanwhile, the processing methods are proposed to adapt to classification of surface. Adopting 3+2 axis method in 5 axis machine to processing complex surface with different features by sub-regional process will effectively improve the surface quality and extend tool life. The paper finally put forward the high speed supplementary processing technology to process the boundary and transition area of surface.

Machining of Free-Form Surface Base on Cutter Shaft Tilt Method with Ball-End Cutter

A new tool path generation method based on cutter shaft tilt method was proposed for free-form surface machining by using Ball-end Cutter. Firstly, it introduces the processing quality problems caused by traditional ball-end mill processing. Then cutter shaft tilt was proposed to avoid the above questions. Analyzing the different machining efficiency at the different angle, and then cutter shaft tilt compensation method which based on above method could avoid that problem was proposed. After the paths calculation to a real surface and simulation, the result shows that, comparing to traditional machining method, the new method reduced efficiently phenomenon of extruding and scratching surface. It meets five-axis processing accuracy requirements.

Research on Instantaneous Cutting Force of High Speed Ball-End Milling Cutter

For the instability of ball-end milling cutter in high speed milling, instantaneous cutting process of high speed milling hardened steel was studied. The model of instantaneous cutting layer parameters of high speed ball-end cutter was established, and the influence of cutting speed and inclination angles on instantaneous cutting layer parameters were obtained. Using the model, instantaneous cutting force was studied, and high speed milling experiment was processed. Results show that the increase of cutting speed makes the change rate of cutting layer parameters increasing, leads to the energy concentration in cutting process, and increases the impact on milling cutter. The increase of inclination angle makes the instantaneous cutting layer parameters show a trend of decrease and the decrease of cutting thickness more rapidly, which caused instantaneous unit cutting force to increase and the instantaneous main cutting force appears increasing trend, and the cutting process become unstable.

Ball-End Milling Force Modeling and Simulation Based on Cutting Path Optimization Experiments

Modeling and simulation of ball-end milling cutter has an important means in studying milling process characteristics. Most scholars ignore practicability analysis before modeling, according to this, modeling and simulation of optimization path is proposed based on cutting path optimization experiment in this paper, which simplifies modeling and simulation and makes model development and practical application have more pertinence and practicality.

5-axis flank milling free-form surfaces considering constraints

A new tool path generation method of flank milling considering constraints is proposed for ball-end cutters in this paper. It will not only reduce the machining error range but also meet the following two constraints: (a) The ball end of the milling tool is tangential to the constraint surface; (b) There is no overcut and the minimum error is zero, which is called nonnegative-error constraint. The two constraints are very useful in some situations of engineering applications, such as flank milling impeller blades. Based on the proposed method, two types of cutter will be used to generate tool paths for the same designed surface and constraint surface. The effectiveness and accuracy of the proposed method will be finally proved with some examples.

Dynamics Characteristics of High Speed Ball-End Milling Cutter for Machining Hardened Steel

In order to depress cutter vibration caused by high hardness and periodic change of cutting force in high speed milling complex surface, investigated the modal characteristics of ball-end milling cutter through the modal analysis and transient analysis. Using the models of dynamic cutting force and cutting vibration, acquired dynamics characteristics of high speed ball-end milling cutter by the spectrum analysis of dynamic cutting force, simulation analysis of cutting vibration and experiment of high speed milling hardened steel. Results indicate that high speed ball-end milling energy concentrates in few special frequencies, the rotational speed and the numbers of cutter teeth determine the fundamental frequency. High speed ball-end milling cutter easily makes radial bending vibration by the lower modal characteristics, the overhang and inclination angle of cutter affect its dynamics characteristics significantly, and the modal parameters and vibration model of cutter acquired by step response method have higher credibility.

Research on Multi-Axis High Speed Machining Milling Force of Aeroengine Impeller

On the basis of the ball-end milling feature during high-speed machining impeller, the relationship between cutting force and chips is analyzed in this paper. The model of ball-end milling cutter cutting force is founded through differential method. And the coefficients solution of cutting force model is expounded. Besides, the coefficients solution and the cutting force model simulation are implemented by the software Matlab.