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.

Generating Spiral Paths for Sculptured Surfaces Machining

2006 ◽  
Author(s):  
Zhiyang Yao
Keyword(s):  
Surface Finish ◽  
End Milling ◽  
Sculptured Surfaces ◽  
Cutting Efficiency ◽  
Final Surface ◽  
Cutter Path ◽  
End Mills ◽  
Cusp Height ◽  
Major Factors ◽  
Final Surface Finish

To machine sculptured surfaces, ball end mills are mainly used to reach the final surface finish requirements. During machining, the cusp height is one of the major factors defining the final surface finish smoothness. A cutter path that maintains a high cutting efficiency as well as a constant cusp height is desired. Spiral curves, with the property of not requiring extra linkage segments between two adjacent arms can be used to generate a smooth cutter path. In this paper, a geometric algorithm for generating spiral cutter paths for ball end milling in machining sculptured surfaces is presented.

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.

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.

scholarly journals DYNAMICS OF FIVE-AXIS END MILLING PROCESS

2019 ◽  
Vol 4 (7) ◽  
pp. 108-120
Author(s):  
Б. Пономарев ◽  
Boris Ponomarev ◽  
Хьен Нгуен ◽  
Hien Nguyen
Keyword(s):  
Cutting Forces ◽  
End Milling ◽  
Milling Process ◽  
Free Form ◽  
Machine Model ◽  
End Mills ◽  
Tool Position ◽  
Five Axis ◽  
Free Form Surfaces ◽  
End Milling Process

The article presents the experimental results of the influences of machining conditions and tool orientation on cutting forces during the end milling of free-form surfaces. A series of experiments are carried out on the machining of steel 3 blanks on a five-axis milling machine model HSC 75 linear using 2-flute and 4-flute ball end mills from MITSUBISHI with diameters from 5 mm to 10 mm. The dependency diagrams and graphs of cutting forces and their projections on cutting time are given at different spindle speeds, feeds per tooth, depths of cut, tilt angles and lead angle when using different ball end mills. Based on the results of the analysis of experimental data, the theoretical conclusion about the increase in cutting forces with increasing feed per tooth, cutting depth and spindle speed in relation to the ball end milling process is confirmed. The critical tool positions with respect to the surface, at which cutting forces have maximum values, are revealed. The obtained results allow developing recommendations for the choice of the tool position during end milling of free-form surfaces to reduce loads on the tool

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 Optimization of free-form surface machining using parallel planes strategy and torus milling cutter

2016 ◽  
Vol 232 (2) ◽  
pp. 240-250 ◽  
Author(s):  
Jean-Max Redonnet ◽  
Alejandro Gamboa Vázquez ◽  
Alberto Traslosheros Michel ◽  
Stéphane Segonds
Keyword(s):  
End Milling ◽  
Free Form ◽  
End Mill ◽  
Machining Time ◽  
Surface Machining ◽  
End Mills ◽  
Free Form Surface ◽  
Optimization Methodology ◽  
Free Form Surfaces ◽  
Industrial Part

Machining by parallel planes is a widely used strategy for end-milling of free-form surfaces on 3-axis numerically controlled machines. In industry, this type of machining is generally performed with a hemispherical tool. However, numerous studies have shown the benefits of torus-end mills over ball-end or flat-end mills. More than anything, the machining direction has much influence on productivity while using a torus-end mill. In this context, the choice of the machining direction is of paramount importance when using a torus-end mill in the machining of free-form surfaces. This paper presents an optimization of part machining direction allowing the machining time to be minimized while respecting the maximum imposed scallop height. This optimization methodology is then applied to an industrial part and measurements are performed on this part. The study highlights the interest of optimizing the machining direction and the benefits that can be drawn with respect to machining using a non-optimized direction.

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.

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