Cutter-Workpiece Engagement Calculations by Parallel Slicing for Five-Axis Flank Milling of Jet Engine Impellers

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
W. Ferry ◽  
D. Yip-Hoi
Keyword(s):  
Cutting Forces ◽  
Solid Modeling ◽  
Boundary Representation ◽  
Flank Milling ◽  
Jet Engine ◽  
Current Configuration ◽  
End Mills ◽  
Machining Operations ◽  
Intersection Curves ◽  
Five Axis

Cutter-workpiece engagement maps, or cutting flute entry/exit locations as a function of height, are a requirement for prediction of cutting forces on the tool and workpiece in machining operations such as milling. This paper presents a new method of calculating tool-part intersection maps for the five-axis flank milling of jet engine impellers with tapered ball-end mills. The parallel slicing method (PSM) is a semi-discrete solid modeling technique written in C++ using the ACIS boundary representation solid modeling environment. The tool swept envelope is generated and intersected with the workpiece to obtain the removal volume. It is also subtracted from the workpiece to obtain the finished part. The removal volume is sliced into a number of parallel planes along a given axis, and the intersection curves between each tool move and plane are determined analytically. The swept area between successive tool positions is generated using the common tangent lines between intersection curves, and then removed from the workpiece. This deletes the material cut between tool moves, ensuring correct engagement conditions. Finally, the intersection curves are compared to the planar slices of the updated part, resulting in a series of arcs. The end points of these arcs are joined with linear segments to form the engagement polygon that is used to calculate the engagement maps. Using this method, cutter-workpiece engagement maps are generated for a five-axis flank milling toolpath on a prototype integrally bladed rotor with a tapered ball-end mill. These maps are compared to those obtained from a benchmark cutter-workpiece engagement extraction method, which employs a fast, z-buffer technique. Overall, the PSM appears to obtain more accurate engagement zones, which should result in more accurate prediction of cutting forces. With the method’s current configuration, however, the calculation time is longer.

Cutter-Workpiece Engagement Calculations by Parallel Slicing for Five-Axis Flank Milling of Jet Engine Impellers

2007 ◽  
Author(s):  
W. Ferry ◽  
D. Yip-Hoi
Keyword(s):  
Application Programming Interface ◽  
Solid Modeling ◽  
Flank Milling ◽  
Workpiece Material ◽  
Jet Engine ◽  
End Mills ◽  
Slicing Method ◽  
Machining Operations ◽  
Intersection Curves ◽  
Five Axis

Cutter-workpiece engagement maps, or cutting flute entry/exit locations as a function of height, are a requirement for prediction of cutting-forces on the tool and workpiece in machining operations such as milling. This paper presents a new method of calculating tool-part intersection maps for five-axis flank milling of jet engine impellers with tapered ball-end mills. It is called the parallel slicing method (PSM) and is a semi-discrete solid modeling technique written in C++ using the ACIS B-rep solid modeling environment. Although it is tailored towards five-axis flank milling, it can also be applied to both planar and multi-axis milling processes. The tool swept envelope is generated and intersected with the workpiece to obtain the removal volume. The removal volume is then sliced into a number of parallel planes along a given axis and the intersection curves with the tool and each plane are determined analytically. The swept area between the intersection curves of successive tool moves is calculated by solving for the area enclosed by the tangent lines. This area is removed from the workpiece material, which deletes the material cut between tool moves. Finally, the intersection curves are compared with the planar slices of the updated part, which results in a series of arcs. The end points of these arcs are joined with linear segments to form the engagement polygon which is used to calculate the engagement maps. Using this method, cutter-workpiece engagement maps are generated for a five-axis flank milling toolpath on a prototype integrally bladed rotor (IBR) with a tapered ball-end mill. These maps are compared with those obtained from a benchmark cutter-workpiece engagement calculation method – the Manufacturing Automation Laboratory’s Virtual Machining Interface (MAL-VMI). The MAL-VMI uses an application programming interface (API) in a commercial NC verification software package to obtain cutter-part intersections through a fast, z-buffer technique. Overall, the parallel slicing method appears to obtain more accurate engagement zones than those given by the MAL-VMI, although the calculation time is longer.

Virtual Five-Axis Flank Milling of Jet Engine Impellers: Part 1 — Mechanics of Five-Axis Flank Milling

2007 ◽  
Author(s):  
W. Ferry ◽  
Y. Altintas
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Friction Angle ◽  
Flank Milling ◽  
Cutting Force Prediction ◽  
Jet Engine ◽  
End Mills ◽  
Five Axis

Jet engine impeller blades are flank-milled with tapered, helical, ball-end mills on five-axis machining centers. The impellers are made from difficult-to-cut titanium or nickel alloys, and the blades must be machined within tight tolerances. As a consequence, deflections of the tool and flexible workpiece can jeopardize the precision of the impellers during milling. This work is the first of a two part paper on cutting force prediction and feed optimization for the five-axis flank milling of an impeller. In Part I, a mathematical model for predicting cutting forces is presented for five-axis machining with tapered, helical, ball-end mills with variable pitch and serrated flutes. The cutter is divided axially into a number of differential elements, each with its own feed coordinate system due to five-axis motion. At each element, the total velocity due to translation and rotation is split into horizontal and vertical feed components, which are used to calculate total chip thickness along the cutting edge. The cutting forces for each element are calculated by transforming friction angle, shear stress and shear angle from an orthogonal cutting database to the oblique cutting plane. The distributed cutting load is digitally summed to obtain the total forces acting on the cutter and blade. The model can be used for general five-axis flank milling processes, and supports a variety of cutting tools. Predicted cutting force measurements are shown to be in reasonable agreement with those collected during a roughing operation on a prototype integrally bladed rotor (IBR).

Virtual Five-Axis Flank Milling of Jet Engine Impellers—Part I: Mechanics of Five-Axis Flank Milling

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
W. B. Ferry ◽  
Y. Altintas
Keyword(s):  
Cutting Forces ◽  
Orthogonal Cutting ◽  
Cutting Tools ◽  
Chip Thickness ◽  
Friction Angle ◽  
Flank Milling ◽  
Cutting Force Prediction ◽  
Jet Engine ◽  
End Mills ◽  
Five Axis

This work is the first of a two part paper on cutting force prediction and feed optimization for the five-axis flank milling of jet engine impellers. In Part I, a mathematical model for predicting cutting forces is presented for five-axis machining with tapered, helical, ball-end mills with variable pitch and serrated flutes. The cutter is divided axially into a number of differential elements, each with its own feed-coordinate system due to five-axis motion. At each element, the total velocity due to translation and angular motion is split into horizontal and vertical feed components, which are used to calculate total chip thickness along the cutting edge. The cutting forces for each element are calculated by transforming friction angle, shear stress, and shear angle from an orthogonal cutting database to the oblique cutting plane. The distributed cutting load is digitally summed to obtain the total forces acting on the cutter and blade. The model can be used for general five-axis flank milling processes, and supports a variety of cutting tools. Predicted cutting forces are shown to be in reasonable agreement with those collected during a roughing operation on a prototype integrally bladed rotor.

ANALYSIS OF THE CORRELATION BETWEEN FRACTAL STRUCTURE OF CUTTING FORCE SIGNAL AND SURFACE ROUGHNESS OF MACHINED WORKPIECE IN END MILLING OPERATION

Fractals ◽  
2019 ◽  
Vol 27 (02) ◽  
pp. 1950013 ◽  
Author(s):  
AHMAD THUFFAIL THASTHAKEER ◽  
ALI AKHAVAN FARID ◽  
CHANG TECK SENG ◽  
HAMIDREZA NAMAZI
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Surface Quality ◽  
Cutting Forces ◽  
End Milling ◽  
Complex Structure ◽  
Machined Surface ◽  
End Mills ◽  
Machining Operations

Analysis of the machined surface is one of the major issues in machining operations. On the other hand, investigating about the variations of cutting forces in machining operation has great importance. Since variations of cutting forces affect the surface quality of machined workpiece, therefore, analysis of the correlation between cutting forces and surface roughness of machined workpiece is very important. In this paper, we employ fractal analysis in order to investigate about the complex structure of cutting forces and relate them to the surface quality of machined workpiece. The experiments have been conducted in different conditions that were selected based on cutting depths, type of cutting tool (serrated versus. square end mills) and machining conditions (wet and dry machining). The result of analysis showed that among all comparisons, we could only see the correlation between complex structure of cutting force and the surface roughness of machined workpiece in case of using serrated end mill in wet machining condition. The employed methodology in this research can be widely applied to other types of machining operations to analyze the effect of variations of different parameters on variability of cutting forces and surface roughness of machined workpiece and then investigate about their correlation.

Virtual Five-Axis Flank Milling of Jet Engine Impellers—Part II: Feed Rate Optimization of Five-Axis Flank Milling

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
W. B. Ferry ◽  
Y. Altintas
Keyword(s):  
Feed Rate ◽  
Tool Path ◽  
Fixed Time ◽  
Flank Milling ◽  
Tool Deflection ◽  
Jet Engine ◽  
Root Finding ◽  
Five Axis ◽  
Feed Rate Optimization ◽  
Chip Load

This paper presents process optimization for the five-axis flank milling of jet engine impellers based on the mechanics model explained in Part I. The process is optimized by varying the feed automatically as the tool-workpiece engagements, i.e., the process, vary along the tool path. The feed is adjusted by limiting feed-dependent peak outputs to a set of user-defined constraints. The constraints are the tool shank bending stress, tool deflection, maximum chip load (to avoid edge chipping), and the torque limit of the machine. The linear and angular feeds of the tool are optimized by two different methods—a multiconstraint based virtual adaptive control of the process and a nonlinear root-finding algorithm. The five-axis milling process is simulated in a virtual environment, and the resulting process outputs are stored at each position along the tool path. The process is recursively fitted to a first-order process with a time-varying gain and a fixed time constant, and a simple proportional-integral controller is adaptively tuned to operate the machine at threshold levels by manipulating the feed rate. As an alternative to the virtual adaptive process control, the feed rate is optimized by a nonlinear root-finding algorithm. The virtual cutting process is modeled as a black box function of feed and the optimum feed is solved for iteratively, respecting tool stress, tool deflection, torque, and chip load constraints. Both methods are shown to produce almost identical optimized feed rate profiles for the roughing tool path discussed in Paper I. The new feed rate profiles are shown to considerably reduce the cycle time of the impeller while avoiding process faults that may damage the part or the machine.

Design of a CAM System for End Mills Based on Solid Modeling

2011 ◽  
Vol 201-203 ◽  
pp. 841-845
Author(s):  
Zhan Hua You ◽  
Fei Tang ◽  
Shu Zhe Li ◽  
Xiao Feng Yue ◽  
Xiao Hao Wang
Keyword(s):  
Solid Modeling ◽  
Numerical Control ◽  
Design Parameters ◽  
End Mill ◽  
Nc Code ◽  
Inner Radius ◽  
End Mills ◽  
Grinding Machine ◽  
Five Axis ◽  
Mill Machining

To facilitate the manufacturing of an end mill, this paper presents a manufacturing model of a flat-end mill using a five-axis computer numerical control (CNC) grinding machine. Using input data of end mill geometry, wheels geometry, wheel setting and machine setting, the NC code for machining will be generated directly from a solid modeling then used as input to simulate the end mill machining in 3 Dimension before machining. The 3D simulation system of the end mill grinding is generated by VBA and AutoCAD2008. Machining simulation consists of a sequence of Boolean operations on difference between the tool and the grinding wheels through NC code. Then the major design parameters of a cutter, such as relief angle and inner radius, can be verified by interrogating the section profile of its solid model. The manufacturing model presented in this paper provides a practical and efficient method for developing CAM software for the manufacture of an end mill.

Prediction of Cutter-Workpiece Engagement for Five-Axis Ball-End Milling

2014 ◽  
Vol 800-801 ◽  
pp. 254-258 ◽  
Author(s):  
Gang Gang Ju ◽  
Qing Hua Song ◽  
Zhan Qiang Liu
Keyword(s):  
Cutting Forces ◽  
End Milling ◽  
Complex Surface ◽  
Boundary Representation ◽  
Surface Machining ◽  
Ball End Milling ◽  
Tool Axis ◽  
Discrete Methods ◽  
Representation Method ◽  
Five Axis

Five-axis ball-end milling technology is widely used in many industries such as aerospace, automotive and die-mold for complex surface machining. Despite recent advances in machining technology, productivity in five-axis ball-end milling is still limited due to the high cutting forces and stability. Moreover, cutting forces in machining is determined by extracting the cutter workpiece engagement (CWE) from the in-process workpiece. A discrete boundary representation method is developed. Cutter is firstly divided into disk elements along the tool axis. And in each disk element, boundary representation based exact Boolean method is introduced for extracting complex cutter-workpiece engagements at every cutter location due to its efficiency and speed over other discrete methods. Developed engagement model is proved to calculate complex engagement regions between tool and workpiece efficiently and accurately.

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

Virtual Five-Axis Flank Milling of Jet Engine Impellers: Part 2 — Feed Rate Optimization of Five-Axis Flank Milling

2007 ◽  
Author(s):  
W. Ferry ◽  
Y. Altintas
Keyword(s):  
Feed Rate ◽  
Tool Path ◽  
Flank Milling ◽  
Tool Deflection ◽  
Jet Engine ◽  
Root Finding ◽  
Non Linear ◽  
Five Axis ◽  
Feed Rate Optimization ◽  
Chip Load

This paper presents optimization schemes for the five-axis flank milling of jet engine impellers based on the mechanics model explained in Part I. The process is optimized by varying the feed automatically as the tool-workpiece engagements, i.e. the process, varies along the tool path. The feed is adjusted by limiting feed-dependent peak outputs to a set of user-defined constraints. These outputs are tool shank bending stress, tool deflection, maximum chip load (to avoid edge chipping) and the torque limit of the machine. The linear and angular feeds of the machine are optimized by two different methods — a multi-constraint based virtual adaptive control of the process and a non-linear root finding algorithm. The five-axis milling process is simulated in a virtual environment, and the resulting process outputs are stored at each position along the tool path. The process is recursively fitted to a first order process with a time varying gain and a fixed time constant, and a simple Proportional Integral controller is adaptively tuned to operate the machine at threshold levels by manipulating the feedrate. As an alternative to virtual adaptive process control, the feedrate is optimized by a non-linear root-finding algorithm. The optimum feed is solved for iteratively, respecting tool stress, tool deflection, torque and chip load constraints, using a non-linear root finding algorithm. Both methods are shown to produce almost identical optimized feed rate profiles for the roughing tool path discussed in Part I of the paper. The new feed rate profiles are shown to considerably reduce the cycle time of the impeller while avoiding process faults that may damage the part or the machine.

IMPROVING THE EFFICIENCY OF MILLING HOLES WITH A SMALL-SIZED TOOL IN THE CONDITIONS OF AUTOMATED PRODUCTION

2021 ◽  
Vol 2021 (10) ◽  
pp. 13-21
Author(s):  
Vladimir Davydov ◽  
Aleksandr Nikitenko ◽  
Mihail Gimadeev ◽  
Vera Berkun
Keyword(s):  
Cutting Forces ◽  
Small Diameter ◽  
Machining Parameters ◽  
Optimal Range ◽  
Helix Pitch ◽  
Key Factor ◽  
End Mills ◽  
Tool Strength ◽  
Machining Operations ◽  
Cutting Modes

The purpose of the paper. In order to solve the problems of increasing the efficiency of machining operations of small diameter holes by milling, the optimal range of cutting modes and helix pitch for the machining strategy with helical interpolation is established. The reduction of labor intensity and costs of hole machining when treating holes in alloyed corrosion-resistant steels is experimentally confirmed. Research methods. In this paper, the issues of machining blind holes by helical interpolation milling with end cylindrical carbide cutters of relatively small dimensions in parts made of 12X18N10T alloy are considered. The features of this machining are availability of significant axial and radial components of the cutting forces with relatively low tool strength. This leads to the fact that a key factor of the tool failure is its mechanical failure, the cause of which is an increase in cutting forces due to the edge of the cutter being chipped. Research results and novelty. It has been experimentally proved that the most rational machining parameters to ensure the specified accuracy and surface quality of the machined holes when using a strategy of helical interpolation milling will be the choice of the helix pitch p = 0.2 mm, the feed range F = 0.075-0.11 mm /tooth, which corresponds to the minute feeds of the milling center 450-675 mm/min. Conclusions. The optimal range of cutting modes is found in the feed range from 450 to 675 mm/min, with a helical interpolation pitch of 0.2 mm. The accuracy and roughness of the holes obtained by milling with end mills with a diameter of 3 mm for steel 12X18N10T is evaluated.

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