Modeling of Five-Axis Ball-End Milling with Tool Orientation Effects

2022 ◽  
pp. 591-600
Author(s):  
Minh-Quang Tran ◽  
Vu Thi Lien ◽  
Meng-Kun Liu ◽  
Thi Thanh Nga Nguyen
Keyword(s):  
End Milling ◽  
Tool Orientation ◽  
Ball End Milling ◽  
Orientation Effects ◽  
Five Axis

Tool Orientation Planning in Milling With Process Dynamic Constraints: A Minimax Optimization Approach

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Tao Huang ◽  
Xiao-Ming Zhang ◽  
Jürgen Leopold ◽  
Han Ding
Keyword(s):  
Tool Path ◽  
End Milling ◽  
Tool Path Generation ◽  
Optimization Approach ◽  
Path Generation ◽  
Tool Orientation ◽  
Minimax Optimization ◽  
Ball End Milling ◽  
Dynamic Constraints ◽  
Five Axis

In five-axis milling process, the tool path generated by a commercial software seldom takes the dynamics of the machining process into account. The neglect of process dynamics may lead to milling chatter, which causes overcut, quick tool wear, etc., and thus damages workpiece surface and shortens tool life. This motivates us to consider dynamic constraints in the tool path generation. Tool orientation variations in five-axis ball-end milling influence chatter stability and surface location error (SLE) due to the varying tool-workpiece immersion area and cutting force, which inversely provides us a feasible and flexible way to suppress chatter and SLE. However, tool orientations adjustment for suppression of chatter and SLE may cause drastic changes of the tool orientations and affects surface quality. The challenge is to strike a balance between the smooth tool orientations and suppression of chatter and SLE. To overcome the challenge, this paper presents a minimax optimization approach for planning tool orientations. The optimization objective is to obtain smooth tool orientations, by minimizing the maximum variation of the rotational angles between adjacent cutter locations, with constraints of chatter-free and SLE threshold. A dedicated designed ball-end milling experiment is conducted to validate the proposed approach. The work provides new insight into the tool path generation for ball-end milling of sculpture surface; also it would be helpful to decision-making for process parameters optimization in practical complex parts milling operations at shop floor.

Evaluation of Surface Roughness in Five-Axis Ball-End Milling

2020 ◽  
pp. 21-31
Author(s):  
B.B. Ponomarev ◽  
S.H. Nguyen
Keyword(s):  
Surface Roughness ◽  
Tilt Angle ◽  
End Milling ◽  
Free Form ◽  
Tool Orientation ◽  
Ball End Milling ◽  
Lead Angle ◽  
Tool Tilt Angle ◽  
Five Axis ◽  
Free Form Surfaces

Unlike three-axis machining, five-axis machining allows the end tool or workpiece to be oriented at any angle relative to the machine axis OZ. It can be achieved by changing the values of the tool tilt angle and lead angle relative to the surface normal in the contact zone of the tool surface and the workpiece, taking into account the direction of the table feed. The article presents experimental results of analyzing the influences of tool orientation on transverse roughness during ball end milling using 2-flute and 4-flute 8 mm diameter mills. The analysis the arithmetic mean deviation of the assessed profile at various values of tool tilt angle and lead angle showed that the position of the tool point with a zero cutting speed significantly affects the surface quality. The results of the evaluation of the tool orientation influence on the surface roughness enable the selection of optimal tool orientation angles when developing control programs for end milling of free-form surfaces on five-axis CNC milling machines.

scholarly journals Minimizing Flute Engagement to Adjust Tool Orientation for Reducing Surface Errors in Five-Axis Ball End Milling Operations

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
M. Habibi ◽  
Z. M. Kilic ◽  
Y. Altintas
Keyword(s):  
Optimization Problem ◽  
Tool Path ◽  
End Milling ◽  
Contact Point ◽  
Geometrical Approach ◽  
Tool Orientation ◽  
Ball End Milling ◽  
Surface Errors ◽  
Five Axis ◽  
Path Modification

Abstract Surface errors due to force-induced tool and workpiece deflections are one of the major errors in multi-axis machining of parts especially with thin-walled structures. Dominant approaches to reduce these surface errors are re-machining the part, feed scheduling, and tool path modification. These methods are time consuming and computationally costly, and they rely on experimental data which is used in cutting force and deflection predictions. The present paper introduces a pure geometrical approach to reduce surface errors drastically by minimizing the engagement lengths of flutes’ cutting edges when a point on the flute’s cutting edge is in contact with the design surface. The total engagement length of the flutes’ cutting edges when one of them generates a contact point on the workpiece surface is formulated and considered as the minimization objective function of an optimization problem. Tilt and lead angles, which define the tool orientation, are the design variables of the optimization problem subjected to constraints based on the geometrical requirements of the ball end milling process. The optimization problem uses the nominal tool path to generate an optimal tool path with adjusted tool orientations. The presented method is computationally inexpensive and does not need any experimentally calibrated coefficients to predict cutting forces because of the pure geometrical nature of the approach. The method is experimentally validated through five-axis ball end milling experiments in which more than 90% surface error reduction is achieved.

Modification of Tool Orientation and Position to Compensate Tool and Part Deflections in Five-Axis Ball End Milling Operations

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
M. Habibi ◽  
O. Tuysuz ◽  
Y. Altintas
Keyword(s):  
Cutting Force ◽  
End Milling ◽  
Traditional Approach ◽  
Cutting Speed ◽  
Computational Time ◽  
Blade Surface ◽  
Tool Orientation ◽  
Ball End Milling ◽  
Form Errors ◽  
Five Axis

Tool-workpiece deflection is one of the major error sources in machining thin walled structures like blades. The traditional approach in industry to eliminate this error is based on modifying tool positions after measuring the error on the machined part. This paper presents an integrated model of cutting force distribution on the tool–blade contact, automatic update of blade static stiffness matrix without resorting to time-consuming finite element solutions as the material is removed, the prediction and compensation of static deflection marks left on the blade surface. The main focus of the paper is to compensate the deflection errors by respecting the maximum form errors, collision of tool/machine/workpiece, cutting speed limit at the tool tip, and ball end—blade surface contact constraints. The compensation has been carried out by two modules. The first module adjusts the tool orientation along the path to reduce the error by constructing an optimization problem. This module is computationally inexpensive and results in about 70% error reduction based on the conducted experiments. The modified tool path resulted from the first module is fed to the second module for further reduction of the form errors if needed at the violated cutter locations; hence it takes less computational time than the stand alone approach proposed in the literature. The proposed algorithms have been experimentally validated on five-axis finish ball end milling of blades with about 80% reduction in cutting force induced form errors.

scholarly journals Effect of Tool Orientation on Surface Integrity During Ball End Milling of Titanium Alloy TC17

Procedia CIRP ◽  
2016 ◽  
Vol 56 ◽  
pp. 143-148 ◽  
Author(s):  
Pan Yang ◽  
Changfeng Yao ◽  
Shaohua Xie ◽  
Dinghua Zhang ◽  
Dou Xing Tang
Keyword(s):  
Titanium Alloy ◽  
Surface Integrity ◽  
End Milling ◽  
Tool Orientation ◽  
Ball End Milling
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