Effect of Cutting Conditions on the Stability Lobes for End Milling Process

2010 ◽  
Vol 139-141 ◽  
pp. 748-751
Author(s):  
Min Wan ◽  
Yi Ting Wang ◽  
Wei Hong Zhang ◽  
Jian Wei Dang
Keyword(s):  
End Milling ◽  
Cutting Parameters ◽  
Helix Angle ◽  
Milling Process ◽  
Cutting Condition ◽  
Multiple Delays ◽  
Cutter Runout ◽  
Stability Lobes ◽  
The Stability ◽  
New Phenomena

Milling process will be dominated by multiple delays due to the effect of the cutter runout or the pitch angles of the cutter. In this paper, research efforts are focused on the dynamic behavior of milling processes under different cutting condition parameters such as different radial immersions, feed directions, feeds per tooth and helix angles. To improve the prediction accuracy of stability lobe, the combined influences of feed rate and cutter runout on the stability lobes are also taken into account. The basic principle of the method presented in one existing work is applied to examine the asymptotic stability trends for both down milling and up milling. Some new phenomena for certain combinations of cutting parameters are shown and explained in detail. It is found that as cutter runout occurs, feed per tooth, feed direction and cutter helix angle have great effects on the stability lobes.

scholarly journals Stability Analysis of Milling Process with Multiple Delays

2020 ◽  
Vol 10 (10) ◽  
pp. 3646 ◽  
Author(s):  
Yonggang Mei ◽  
Rong Mo ◽  
Huibin Sun ◽  
Bingbing He ◽  
Kun Bu
Keyword(s):  
Stability Limit ◽  
Helix Angle ◽  
Milling Process ◽  
Machining Process ◽  
Multiple Delays ◽  
Calculation Time ◽  
Discretization Algorithm ◽  
Cutting Chatter ◽  
Regeneration Effect ◽  
The Stability

Cutting chatter is extremely harmful to the machining process, and it is of great significance to eliminate chatter through analyzing the stability of the machining process. In this work, the stability of the milling process with multiple delays is investigated. Considering the regeneration effect, the dynamics of the milling process with variable pitch cutter is modeled as periodic coefficients delayed differential equations (DDEs) with multiple delays. An adaptive variable-step numerical integration method (AVSNIM) considering the effect of the helix angle is developed firstly, which can discretize the cutting period accurately, thereby improving the calculation accuracy of the stability limit of the milling process. The accuracy and efficiency of the AVSNIM are verified through a benchmark milling model. Subsequently, a novel spindle speed-dependent discretization algorithm is proposed, which is combined with the AVSNIM to further reduce the calculation time of the stability lobes diagram (SLD). The simulation experiment results demonstrate that the proposed algorithm can effectively reduce the calculation time.

scholarly journals Stability Prediction of Milling Process with Variable Pitch Cutter

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Gang Jin ◽  
Qichang Zhang ◽  
Shuying Hao ◽  
Qizhi Xie
Keyword(s):  
Helix Angle ◽  
Milling Process ◽  
Depth Of Cut ◽  
Force Model ◽  
Stable Limit ◽  
Variable Pitch ◽  
Tool Geometries ◽  
Piecewise Continuous ◽  
The Stability ◽  
New Phenomena

The use of variable pitch cutter is a known means to increase the stable limit depth of cut by disrupting the regenerative effect. In this paper, an improved semidiscretization algorithm is presented to predict the stability lobes for variable pitch cutters. Modeling efforts develop a straightforward analytical integral force model that can cover any case of piecewise continuous cutting regions regarding the helix angle. The proposed approach has been verified with the comparisons with prior works, time domain simulations, and cutting tests. In addition, the method is also applied to examine the effect of the tool geometries on the stability trends for variable pitch milling. Some new phenomena for certain combinations of parameters are shown and explained.

The Effect of Harmonic Force Components on Regenerative Stability in End Milling

Manufacturing ◽  
2003 ◽  
Author(s):  
J.-J. Junz Wang ◽  
C. M. Zheng ◽  
C. Y. Huang
Keyword(s):  
End Milling ◽  
Helix Angle ◽  
Milling Process ◽  
Fourier Series Expansion ◽  
Harmonic Force ◽  
Average Force ◽  
Dynamic Forces ◽  
Force Components ◽  
The Stability ◽  
Milling Forces

In a systematic manner, this paper investigates the effects of harmonic force components on the regenerative stability of an end milling process. By representing the milling force pulsation in a Fourier series expansion form, the dynamic force components and the average forces due to bi-directional dynamic feed rates are both included in the generalized system dynamics formulation. In the resulting expression for the stability criterion, the spectral features of the milling forces are integrated with the dynamics of the structure, showing the significance or insignificance of the dynamic components of the milling forces in affecting the stability of the milling process. Key system parameters discussed include the magnitude of the average and harmonic forces, the cutter helix angle and the spindle speed. It is shown that a low helix angle and a smaller number of cutting flutes increase the effect of dynamic forces on the system stability. The significance of the harmonic forces is exemplified by the special cutting conditions where the average force becomes zero and the stability limits would be infinite as predicted by models using the average force alone. Improvements in the accuracy of stability lobes resulting from the inclusion of the dynamic forces and the validity of the presented model in general will be illustrated by numerical simulation and verified by experiments as well as by comparison with published results.

Investigation of Dry Cutting and Applications of Cutting Fluid in Ball-End Milling Process

2011 ◽  
Vol 291-294 ◽  
pp. 3013-3023 ◽  
Author(s):  
Somkiat Tangjitsitcharoen ◽  
Channarong Rungruang
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
End Milling ◽  
Cutting Parameters ◽  
Milling Process ◽  
Cutting Fluid ◽  
Cutting Condition ◽  
Dry Cutting ◽  
Ball End Milling ◽  
End Milling Process

In order to realize the environmental hazard, this paper presents the investigation of the machinability of ball-end milling process with the dry cutting, the wet cutting, and the mist cutting for aluminum. The relations of the surface roughness, the cutting force, and the cutting parameters are examined based on the experimental results by using the Response Surface Analysis with the Box-Behnken design. The in-process cutting force is monitored to analyze the relations of the surface roughness and the cutting parameters. The proper cutting condition can be determined easily referring to the minimum use of cutting fluid, and the minimum surface roughness and cutting force of the surface plot. The effectiveness of the obtained surface roughness and cutting force models have been proved by utilizing the analysis of variance at 95% confident level.

scholarly journals Experimental Verification of Chatter-Free Ball End Milling Strategy

2013 ◽  
Vol 7 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Lin Lu ◽  
◽  
Masahiko Sato ◽  
Hisataka Tanaka ◽  
Keyword(s):  
Cutting Tool ◽  
End Milling ◽  
Cutting Parameters ◽  
Cutting Condition ◽  
Chatter Stability ◽  
Chatter Vibration ◽  
Ball End Milling ◽  
Machining Center ◽  
Avoidance Control ◽  
Avoidance Strategy

Chatter vibration frequently occurs in ball end milling. If the characteristics of the cutting tool system and cutting process are known, chatter stability in ball end milling can be evaluated. Hence, in this paper, a chatter-avoidance strategy based on a regenerative chatter theory is proposed to prevent the occurrence of chatter. This consists of a simulation of chatter stability and cutting condition control. When the characteristics of a vibration system change, this chatter-avoidance strategy cannot cope with it. Therefore, another chatter-avoidance control algorism that changes cutting parameters on a machining center is proposed. This can adapt to the change in the characteristics of the vibration systemduring cutting. The effectiveness of the two chatter-avoidance methods proposed is examined through experiments.

scholarly journals Measurement of Micro Burr and Slot Widths through Image Processing: Comparison of Manual and Automated Measurements

2021 ◽  
Author(s):  
FATIH AKKOYUN ◽  
Ali Ercetin ◽  
Kubilay Aslantas
Keyword(s):  
Image Processing ◽  
Cutting Tools ◽  
Cutting Parameters ◽  
Helix Angle ◽  
Milling Process ◽  
Micro Milling ◽  
Inconel 718 Alloy ◽  
Sem Images ◽  
Automated Measurements ◽  
Cutting Length

Abstract In this study, the burr and slot widths formed after micro-milling process are investigated using a rapid and accurate image processing method. The measurements are obtained by processing the images and results were compared with a manual measurement method. In the cutting experiment stage, Inconel 718 alloy was chosen as the workpiece and cutting tools with various specific properties were used. The images of the burr and slots were captured using scanning electron microscope (SEM). Different tool geometries and cutting parameters were considered for choosing the SEM images. Captured images were processed with a computer vision software which was written in C + + programming language and open-sourced computer library (Open CV). The demonstrated approach was successfully measured the slot and burr widths in plain and complex conditions where slot and burr are nested. According to the close findings of manual and automated measurements, it was observed that burr widths increased especially at the down milling sides and slot widths decreased due to the increased cutting length. Specific tool properties such as number of cutting edge, helix angle and cutting length affected the slot and burr widths. It was determined that there is a good correlation between automated and manual measurements of slot and burr widths. The accuracy of the proposed method is above 91%, 98%, and 99% for up milling, down milling, and slot measurements, respectively.

Study on the stability for non-uniform helix angle tools in the milling process

2020 ◽  
Vol 37 (8) ◽  
pp. 387-393
Author(s):  
Qiang Guo ◽  
Ming-Yang Zhang ◽  
Yuan-Shin Lee ◽  
Zhi-Bo Yang ◽  
Yan Jiang ◽  
...  
Keyword(s):  
Helix Angle ◽  
Milling Process ◽  
The Stability

Experimental Investigation on the Effect of Tool Geometry and Cutting Conditions Using Tool Wear Prediction Model for End Milling Process

2014 ◽  
Vol 13 (01) ◽  
pp. 41-54 ◽  
Author(s):  
S. Kalidass ◽  
P. Palanisamy
Keyword(s):  
Tool Wear ◽  
End Milling ◽  
Cutting Parameters ◽  
304 Stainless Steel ◽  
Tool Geometry ◽  
Depth Of Cut ◽  
Work Piece ◽  
Cutting Condition ◽  
Machining Parameter

Tool wear of a cutting tool has a significant impact on the tool life and surface quality of the finished product. Tool wear is influenced by many factors such as cutting parameters, tool geometry, coating type, work piece material, chatter, and cutting condition. In the present work, the design of experiments (DOE) technique has been used for four factors at five levels to conduct experiments. Tool wear is taken as the response variable measured during end milling, while helix angle, spindle speed, feed and depth of cut are taken as the input parameters. The material and tool selected for this study are AISI 304 stainless steel and uncoated solid carbide end mill cutter respectively. The tool wear was measured using tool maker's microscope. The experimental values are used in six sigma software for finding the coefficients to develop the regression model. The direct and interaction effect of the machining parameter with tool wear were analyzed using contour graphs, which helped to select process parameters for reducing tool wear and also ensure quality of milling.

Investigation on Chip Morphology and Surface Quality in High-Speed Ball-End Milling of Inconel 718

2010 ◽  
Vol 443 ◽  
pp. 353-358 ◽  
Author(s):  
Harshad A. Sonawane ◽  
Suhas S. Joshi
Keyword(s):  
Surface Quality ◽  
Inconel 718 ◽  
High Speed ◽  
End Milling ◽  
Chip Morphology ◽  
Helix Angle ◽  
Processing Parameters ◽  
Milling Process ◽  
Machining Parameters ◽  
Ball End Milling

The ball end milling process, commonly used for generating complex shapes, involves continuous variation in the uncut chip dimensions, which depends on the cutter geometry and the machining parameters. The proposed analytical model evaluates the undeformed and the deformed chip dimensions including chip length, width and thickness. The undeformed and deformed chip dimensions, is a function of cutter rotation angle, instantaneous cutter radius, helix angle, and other processing parameters. The surface quality, in the form of surface roughness, during high-speed ball end milling of Inconel 718 is also analysed in this paper.

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