Cutting Force Simulation in Minute Time Resolution for Ball End Milling Under Various Tool Posture

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Isamu Nishida ◽  
Ryuma Okumura ◽  
Ryuta Sato ◽  
Keiichi Shirase
Keyword(s):  
Cutting Force ◽  
End Milling ◽  
Chip Thickness ◽  
Cutting Edge ◽  
New Method ◽  
Uncut Chip Thickness ◽  
Tool Posture ◽  
Voxel Model ◽  
Five Axis ◽  
Milling Forces

A new cutting force simulator has been developed to predict cutting force in ball end milling. In this simulator, uncut chip thickness is discretely calculated based on fully voxel models representing both cutting edge and instantaneous workpiece shape. In the previous simulator, a workpiece voxel model was used to calculate uncut chip thickness under a complex change of workpiece shape. Using a workpiece voxel model, uncut chip thickness is detected by extracting the voxels removed per cutting tooth for the amount of material fed into the cutting edge. However, it is difficult to define the complicated shape of cutting edge, because the shape of cutting edge must be defined by mathematical expression. It is also difficult to model the voxels removed by the cutting edge when tool posture is nonuniformly changed. Therefore, a new method to detect uncut chip thickness is proposed, one in which both cutting edge and instantaneous workpiece shape are fully represented by a voxel model. Our new method precisely detects uncut chip thickness at minute tool rotation angles, making it possible to detect the uncut chip thickness between the complex surface shape of the workpiece and the particular shape of the cutting edge. To validate the effectiveness of our new method, experimental five-axis milling tests using ball end mill were conducted. Estimated milling forces for several tool postures were found to be in good agreement with the measured milling forces. Results from the experimental five-axis milling validate the effectiveness of our new method.

Cutting Force Prediction of Ball End Milling Based on Fully Voxel Representation of Cutting Edge and Instantaneous Workpiece Shape

2017 ◽  
Author(s):  
Isamu Nishida ◽  
Ryuma Okumura ◽  
Ryuta Sato ◽  
Keiichi Shirase
Keyword(s):  
Cutting Force ◽  
End Milling ◽  
Chip Thickness ◽  
Cutting Edge ◽  
Surface Shape ◽  
Uncut Chip Thickness ◽  
Ball End Milling ◽  
Voxel Model ◽  
Voxel Representation ◽  
Milling Forces

A new cutting force simulator has been developed to predict cutting force in ball end milling. This new simulator discretely calculates uncut chip thickness based on a fully voxel representation of the cutting edge and instantaneous workpiece shape. Previously, a workpiece voxel model was used to calculate uncut chip thickness under a complex change of workpiece shape. Using a workpiece voxel model, uncut chip thickness is detected by extracting the voxels removed per cutting edge tooth for the amount of material fed into the cutting edge. However, it is difficult to define the complicated shape of a cutting edge using the workpiece voxel model; the shape of the cutting edge must be defined by a mathematical expression. It is also difficult to model the voxels removed by the cutting edge when the tool posture is non-uniformly changed. We therefore propose a new method to detect uncut chip thickness, one in which both the cutting edge and the instantaneous workpiece shape are fully represented by a voxel model. Our proposed method precisely detects uncut chip thickness at minute tool rotational angles, making it possible to detect the uncut chip thickness between the complex surface shape of the workpiece and the particular shape of the cutting edge. To validate the effectiveness of our proposed method, experimental 5-axis milling tests using a ball end mill were conducted. Estimated milling forces for several tool postures were found to be in good agreement with the measured milling forces. Results from the experimental 5-axis milling validate the effectiveness of our proposed method.

Voxel Based Cutting Force Simulation of Ball End Milling Considering Cutting Edge Around Center Web

2018 ◽  
Author(s):  
Isamu Nishida ◽  
Takaya Nakamura ◽  
Ryuta Sato ◽  
Keiichi Shirase
Keyword(s):  
Cutting Force ◽  
End Milling ◽  
Chip Thickness ◽  
Previous Method ◽  
Cutting Edge ◽  
Force Model ◽  
End Mill ◽  
Uncut Chip Thickness ◽  
Ball End Mill ◽  
Tool Rotation

A new method, which accurately predicts cutting force in ball end milling considering cutting edge around center web, has been proposed. The new method accurately calculates the uncut chip thickness, which is required to estimate the cutting force by the instantaneous rigid force model. In the instantaneous rigid force model, the uncut chip thickness is generally calculated on the cutting edge in each minute disk element piled up along the tool axis. However, the orientation of tool cutting edge of ball end mill is different from that of square end mill. Therefore, for the ball end mill, the uncut chip thickness cannot be calculated accurately in the minute disk element, especially around the center web. Then, this study proposes a method to calculate the uncut chip thickness along the vector connecting the center of the ball and the cutting edge. The proposed method can reduce the estimation error of the uncut chip thickness especially around the center web compared with the previous method. Our study also realizes to calculate the uncut chip thickness discretely by using voxel model and detecting the removal voxels in each minute tool rotation angle, in which the relative relationship between a cutting edge and a workpiece, which changes dynamically during tool rotation. A cutting experiment with the ball end mill was conducted in order to validate the proposed method. The results showed that the error between the measured and predicted cutting forces can be reduced by the proposed method compared with the previous method.

Prediction of Ball End Milling Forces

1996 ◽  
Vol 118 (1) ◽  
pp. 95-103 ◽  
Author(s):  
G. Yu¨cesan ◽  
Y. Altıntas¸
Keyword(s):  
Cutting Forces ◽  
End Milling ◽  
Chip Thickness ◽  
Cutting Conditions ◽  
Analytic Representation ◽  
Rake Face ◽  
Uncut Chip Thickness ◽  
Ball End Milling ◽  
Helical Flute ◽  
Milling Forces

Mechanics of milling with ball ended helical cutters are modeled. The model is based on the analytic representation of ball shaped helical flute geometry, and its rake and clearance surfaces. It is assumed that friction and pressure loads on the rake face are proportional to the uncut chip thickness area. The load on the flank contact face is concentrated on the in cut portion of the cutting edge. The pressure and friction coefficients are identified from a set of slot ball end milling tests at different feeds and axial depth of cuts, and are used to predict the cutting forces for various cutting conditions. The experimentally verified model accurately predicts the cutting forces in three Cartesian directions.

Two-Step Identification of Instantaneous Cutting Force Coefficients and Cutter Runout

2014 ◽  
Vol 887-888 ◽  
pp. 1179-1183 ◽  
Author(s):  
Hong Yan Hao ◽  
Wen Cheng Tang ◽  
Bao Sheng Wang
Keyword(s):  
Cutting Force ◽  
End Milling ◽  
Chip Thickness ◽  
Key Factors ◽  
Cutter Runout ◽  
Cutting Force Coefficients ◽  
Force Coefficients ◽  
Instantaneous Cutting Force Coefficients ◽  
Identification Approach ◽  
Milling Forces

Cutting force coefficients and cutter runout parameters are the key factors for accurate prediction of instantaneous milling forces. A new two-step identification method is presented to calibrate them in end milling. Based on analyzing effects of cutter runout on milling forces, a method of extracting nominal milling forces from measured milling forces is proposed. By calibrating average cutting force coefficients and corresponding average chip thickness, an approach to evaluate the instantaneous cutting force coefficients is proposed. Then, an iterative method is presented to identify cutter runout, and the procedure is also given in detail. Milling tests are performed to test the proposed method, and validity of the identification approach is proved by a good agreement between predicted results and experimental results.

An Approach to Modeling Cutting Forces in Five-Axis Ball-End Milling of Curved Geometries Based on Tool Motion Analysis

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Guo Dongming ◽  
Ren Fei ◽  
Sun Yuwen
Keyword(s):  
Motion Analysis ◽  
Cutting Forces ◽  
End Milling ◽  
Chip Thickness ◽  
Cutting Edge ◽  
Axis Orientation ◽  
Undeformed Chip Thickness ◽  
Ball End Milling ◽  
Tool Motion ◽  
Five Axis

The prediction of five-axis ball-end milling forces is quite a challenge due to difficulties of determining the underformed chip thickness and engaged cutting edge. To solve these concerns, this paper presents a new mechanistic model of cutting forces based on tool motion analysis. In the model, for undeformed chip thickness determination, an analytical model is first established to describe the sweep surface of cutting edge during the five-axis ball-end milling process of curved geometries. The undeformed chip thickness is then calculated according to the real kinematic trajectory of cutting edges under continuous change of the cutter axis orientation. A Z-map method is used to verify the engaged cutting edge and cutting coefficients are subsequently calibrated. The mechanistic method is applied to predict the cutting force. Validation tests are conducted under different cutter postures and cutting conditions. The comparison between predicted and measured values demonstrates the applicability of the proposed prediction model of cutting forces.

scholarly journals Modeling and Estimation of Cutting Forces in Ball Helical Milling Process

2021 ◽  
Author(s):  
Haiyan Wang ◽  
Kexin Tao ◽  
Tian Jin
Keyword(s):  
Cutting Force ◽  
End Milling ◽  
Spherical Surface ◽  
Research Result ◽  
Chip Thickness ◽  
Milling Process ◽  
Helical Milling ◽  
Force Model ◽  
Cutting Force Model ◽  
Milling Forces

Abstract Milling forces play an important role in the milling process and are generally calculated by the mechanistic or numerical methods, reliable model of cutting force is very important for the simulation of milling process, which has big scientific significance to further improve machining quality. Ball helical milling technology is used to make holes based on the cutting principle of helical milling using ball end cutter, due to the influence of spherical surface machining characteristic, the modeling of cutting force in ball helical milling is difficult. Therefore, the main purpose of this paper is to first establish an analytical cutting force model in the ball helical milling process. Considering cutting characteristics in the axial feed, the kinematics of ball helical milling is first presented, then the chip thickness distribution in different directions along the cutting edges are predicted. Furthermore, based on the characteristics of helical milling technology and geometry shape of ball end mill and the classical mechanical cutting force model, through the study on the ball-end milling mechanics, a new relatively accurate theoretical cutting force model is established. At the same time, cutting force coefficients are identified through instantaneous force method according to the Ti-alloy experimental research result. Finally, higher simulation precision of cutting force model in ball helical milling process is received.

Mechanism of Cutting Force and Surface Generation in Dynamic Milling

1991 ◽  
Vol 113 (2) ◽  
pp. 160-168 ◽  
Author(s):  
D. Montgomery ◽  
Y. Altintas
Keyword(s):  
Cutting Force ◽  
Surface Finish ◽  
Cutting Forces ◽  
Chip Thickness ◽  
Dominant Frequency ◽  
Milling Process ◽  
Cutting Edge ◽  
Surface Generation ◽  
Uncut Chip Thickness ◽  
Improved Model

An improved model of the milling process is presented. The model proposes a method of determining cutting forces in five distinct regions where the cutting edge travels during dynamic milling. Trochoidal motion of the milling cutter is used in determining uncut chip thickness. The kinematics of the cutter and workpiece vibrations are modelled, which identifies the orientation and velocity direction of the cutting edge during dynamic cutting. The model allows the prediction of forces and surface finish under rigid or dynamic cutting conditions. The proposed mechanism of chip thickness, force and surface generation is proven with simulation and experimental results. It is found that when the tooth passing frequency is selected to be an integer ratio of a dominant frequency of tool-workpiece structure in milling imprint of vibrations on the surface finish is avoided.

Cutting Force Model for Contour Surface Machining of Gear Indexing Cam with Flat End Milling

2004 ◽  
Vol 471-472 ◽  
pp. 122-126 ◽  
Author(s):  
P.Q. Guo ◽  
Chuan Zhen Huang ◽  
Ping Zhao
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Chip Thickness ◽  
Depth Of Cut ◽  
Force Model ◽  
Uncut Chip Thickness ◽  
Thickness Change ◽  
Flat End Milling ◽  
Axial Depth

This paper presents a model to predict the cutting forces for flat end milling as machining gear indexing cam. Rotation feeding makes axial depth of cut and uncut chip thickness change during cutting process. The development of the model is based on the analysis of cutting edge expression. According to the existing the relationship of the local cutting force and chip load and assuming the cutter to be divided into a number of differential elements in the axial direction of the cutter, the model is derived by summarising the cutting forces produced by each differential cutter disc engaged in the cut. The equation for calculating uncut chip thickness of differential disc is educed. In order to avoid the complex computing for axial depth of cut of the entire edge, a unit square window function and its criterion are introduced to estimate whether a segment of edge is in engaging range.

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