scholarly journals Impact of Different CAM Strategies and Cutting Parameters on Machining Free-Form Surfaces with Ball-End Milling Tools in Terms of Micro and Macro Accuracy

2021 ◽  
Vol 18 (7) ◽  
pp. 109-127
Author(s):  
Bálint Varga ◽  
Balázs Mikó
Keyword(s):  
End Milling ◽  
Cutting Parameters ◽  
Free Form ◽  
Ball End Milling ◽  
Free Form Surfaces ◽  
Milling Tools

scholarly journals The Effect of the Feed Direction on the Micro- and Macro Accuracy of 3D Ball-end Milling of Chromium-Molybdenum Alloy Steel

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4038
Author(s):  
Balázs Mikó ◽  
Bálint Varga ◽  
Wojciech Zębala
Keyword(s):  
Surface Roughness ◽  
Metal Cutting ◽  
Tool Path ◽  
End Milling ◽  
Cutting Parameters ◽  
Machining Process ◽  
Free Form ◽  
Dimensional Error ◽  
Ball End Milling ◽  
Free Form Surfaces

The machining of free form surfaces is one of the most challenging problems in the field of metal cutting technology. The produced part and machining process should satisfy the working, accuracy, and financial requirements. The accuracy can describe dimensional, geometrical, and surface roughness parameters. In the current article, three of them are investigated in the case of the ball-end milling of a convex and concave cylindrical surface form 42CrMo4 steel alloy. The effect of the tool path direction is investigated and the other cutting parameters are constant. The surface roughness and the geometric error are measured by contact methods. Based on the results, the surface roughness, dimensional error, and the geometrical error mean different aspects of the accuracy, but they are not independent from each other. The investigated input parameters have a similar effect on them. The regression analyses result a very good liner regression for geometric errors and shows the importance of surface roughness.

Mechanistic Modeling of the Ball End Milling Process for Multi-Axis Machining of Free-Form Surfaces

2000 ◽  
Vol 123 (3) ◽  
pp. 369-379 ◽  
Author(s):  
Rixin Zhu ◽  
Shiv G. Kapoor ◽  
Richard E. DeVor
Keyword(s):  
End Milling ◽  
Chip Thickness ◽  
Mechanistic Modeling ◽  
Free Form ◽  
Surface Geometry ◽  
Workpiece Surface ◽  
Ball End Milling ◽  
Modeling Approach ◽  
Free Form Surfaces ◽  
Cutting Point

A mechanistic modeling approach to predicting cutting forces is developed for multi-axis ball end milling of free-form surfaces. The workpiece surface is represented by discretized point vectors. The modeling approach employs the cutting edge profile in either analytical or measured form. The engaged cut geometry is determined by classification of the elemental cutting point positions with respect to the workpiece surface. The chip load model determines the undeformed chip thickness distribution along the cutting edges with consideration of various process faults. Given a 5-axis tool path in a cutter location file, shape driving profiles are generated and piecewise ruled surfaces are used to construct the tool swept envelope. The tool swept envelope is then used to update the workpiece surface geometry employing the Z-map method. A series of 3-axis and 5-axis surface machining tests on Ti6A14V were conducted to validate the model. The model shows good computational efficiency, and the force predictions are found in good agreement with the measured data.

Finding Cutter Engagement for Ball End Milling of Tessellated Free-Form Surfaces

2005 ◽  
Author(s):  
Zhiyang Yao
Keyword(s):  
Surface Finish ◽  
Feed Rate ◽  
End Milling ◽  
Geometric Algorithms ◽  
Free Form ◽  
Ball End Milling ◽  
Final Surface ◽  
End Mills ◽  
Free Form Surfaces ◽  
Final Surface Finish

In fabricating free-form surfaces, ball end mills are mainly used to reach the final surface finish requirements. In the milling processes, cutter engagement value measures what portion of the cutter is involved in machining at a given instant of time. This paper presents geometric algorithms for estimating cutter engagement values for ball end milling processes of tessellated free-form surfaces. The cutter engagement value calculated here can be used later on in generating efficient cutter paths, as well as performing adaptive feed rate controls.

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.

Cutter/Work Interference and Surface Generation in Ball End Milling

2011 ◽  
Vol 188 ◽  
pp. 572-577
Author(s):  
Toshiyuki Obikawa ◽  
Tetsuri Senoda
Keyword(s):  
High Speed ◽  
End Milling ◽  
Surface Generation ◽  
Free Form ◽  
High Speed Machining ◽  
Optimum Conditions ◽  
Ball End Milling ◽  
Swept Volume ◽  
Free Form Surfaces ◽  
Work Interference

Prediction of cutting performance in ball end milling of free form surfaces is increasingly important for selecting the optimum conditions in high speed machining. In this paper, a simulator for ball end milling was developed using a precise cutter model, which consisted of rake and flank faces and chisel edges. Then, the swept volume with the cutter was calculated for each time increment and removed to update the shape of the in-process workpiece. Through this process, the detail topographies of finished surfaces were obtained for different cutting conditions and tool postures. The removal rates of workpiece with rake face and other faces were also calculated at any moment of increment.

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.

Surface Quality Prediction in Case of Steep Free Form Surface Milling

2016 ◽  
Vol 686 ◽  
pp. 119-124 ◽  
Author(s):  
Balázs Mikó
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Tool Path ◽  
Complex Geometry ◽  
Cutting Parameters ◽  
Free Form ◽  
Milling Cutter ◽  
Good Surface ◽  
2.5D Milling ◽  
Free Form Surfaces

The machining of free form surfaces is a current and important issue in die and mould industry. Beside the complex geometry, an accurate and productive machining and good surface quality are needed. The finishing milling carried out by a ball-end or toroid milling cutter defines the surface quality, which is characterized by the surface roughness and the tool path trace. The surface quality is defined by the properties of the milling cutter, the type of surface and its position, as well as the cutting parameters. This article focuses on the z-level milling of steep surfaces by 2.5D milling strategy. The importance of the different elements of the tool path is presented, the effect of cutting parameters is investigated, and a formula to predict the surface roughness is suggested.

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