Research on 5 Axis Tool-Path Based on Constant Shearing Stress for Milling Thin-Wall Ceramics

2015 ◽  
Vol 778 ◽  
pp. 152-158
Author(s):  
Quan Ping Sun ◽  
Hai Bing Wu ◽  
Qian Liang Chen
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Cutting Parameters ◽  
Good Method ◽  
Air Cooling ◽  
Thin Wall ◽  
Shearing Stress ◽  
Crack Control ◽  
Tool Paths ◽  
Machining Center

Ceramics is a material of hardness and brittle, so crack arises easily when it is machined. To improve its cutting performance and enhance machining quality, a dynamic model based on constant-shearing-stress is built for milling ceramics, therefore some cutting parameters can be optimized by the model for no crack machining; moreover, an algorithm of 5 axis tool-path designed with constant-shearing-stress is put forward. According to the model and the algorithm, 5 axis tool paths of decreasing-cutting-depth and decreasing-feed-rate are realized; these are really accurate and smooth through VERICUT software simulating. Using Mikron high-speed machining center, several experiments were done to find a good method of crack control in milling thin-wall ceramics. The results show that the experiment based on the 5 axis tool paths with high pressure air cooling and regional cutting is rather successful because of no cracking in cutting thin-wall ceramics, compared to others.

A Bi-Directional Ultrasonic Elliptical Vibration Actuator (BUEVA) for Micro Machining

2009 ◽  
Author(s):  
Ali H. Ammouri ◽  
Ramsey F. Hamade
Keyword(s):  
Tool Path ◽  
Cutting Parameters ◽  
Micro Machining ◽  
Tool Positioning ◽  
Elliptical Vibration ◽  
Machining Center ◽  
Precise Tool ◽  
Multilayer Actuator ◽  
Tool Motion ◽  
Ultrasonic Elliptical Vibration

Presented is the detailed design and implementation of a bi-directional ultrasonic elliptical vibration actuator (BUEVA) for micro machining. Removal of material occurs via a generated elliptical tool motion resembling a natural ‘spoon feeding’ action in contrast to in-plane, horizontal motion utilized by most existing setups. The motion is generated by two stacked ceramic multilayer actuator ring (SCMAR) piezo elements vibrating out of phase in the tool’s axial and transverse directions. The amplitude of vibration of the tool is controlled in order to vary the cutting depth according to the desired cutting parameters. To ensure precise tool positioning, the BUEVA actuator is fitted to a 3-axis precision machining center that provides the necessary tool path. The cutting forces and the resulting surface finish are both numerically modeled and then experimentally measured by a 3-axis mini dynamometer and a surface profilometer, respectively. Preliminary cutting results show good dimensional definition and surface integrity.

Investigation and Modeling of Flag Generation in Honeycomb Sandwich Panel Machining

2018 ◽  
Author(s):  
Derek M. Yip-Hoi ◽  
David D. Gill
Keyword(s):  
Geometric Modeling ◽  
High Speed ◽  
Tool Path ◽  
Sandwich Panels ◽  
Cutting Parameters ◽  
Honeycomb Structures ◽  
Anisotropic Mechanical Properties ◽  
Honeycomb Sandwich ◽  
Low Stiffness ◽  
The Impact

Light weight honeycomb structures lend themselves to important applications in aerospace. These range from aerodynamic and structural components such as wing edges, flaps, rotor blades and engine cowlings, to aircraft interior structures such as overhead luggage bins, compartment liners, bulkheads and the monument structures found in galleys and lavatory areas. Often the honeycomb is formed into a composite ply sandwich with fiberglass face sheets bonded to the honeycomb core. These panels are cut to shape using CNC routers and specially designed cutting tools. However, the quality of the cuts generated even with these special tools leaves much to be desired. The low stiffness of the structure leads to imperfections such as fraying of the cut face sheet edges and the generation of flags along the cut honeycomb edge. These impact the ease of assembly and often require manually intensive reworking to mitigate. The cutting of honeycomb structures and sandwich panels is challenging due to low stiffness, anisotropic mechanical properties and a high proportion of interrupted cutting due to the air voids that are present. The cutting mechanics are not well understood at this time. This paper presents findings from the study of cutting of honeycomb sandwich panels using high speed videography and correlates these with results of geometric modeling of the engagement between the cutter and workpiece. The study includes the impact of the trajectory of the tool path through the cell structures on the generation of flagging. It also reports on the effects of two different cutting tool geometries and the introduction of a lead angle on the size and structure of the flags generated. These findings present the case for a research regime similar to the one completed for solid metals, into modeling the mechanics behind machining honeycomb structures. This will help manufacturers using these materials to make better choices in the tools, cutting parameters and machining strategies that they employ in their process planning.

Experiment and Analysis on Side Milling Deformation of Thin-Walled Workpieces Using Laddered Symmetrical Tool Path

2013 ◽  
Vol 710 ◽  
pp. 233-237
Author(s):  
Yong Qiang He
Keyword(s):  
Parameter Optimization ◽  
Tool Path ◽  
Cutting Parameters ◽  
Deformation Characteristics ◽  
Side Milling ◽  
Machining Center ◽  
Thin Walled ◽  
Aluminum 7075 ◽  
Machining Parameter ◽  
Deformation Error

The aluminum 7075 workpieces are machined on a vertical machining center KX650 using laddered symmetrical tool path. The deformation characteristics are studied under different cutting conditions. Different cutting parameters are changed one by one in side milling tests to find out their impact on deformation error. The analyzed result provides a solid basis for machining parameter optimization in side milling thin-walled workpieces.

The Process Strategies of Mould High-Speed Machining and their Applications in the Environment of PowerMILL

2011 ◽  
Vol 188 ◽  
pp. 542-548 ◽  
Author(s):  
Jie Liu
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Feed Speed ◽  
Machining Parameters ◽  
High Speed Machining ◽  
Whole Process ◽  
Machining Strategies ◽  
Selection Of

High-speed machining requires the support of high intelligent CAM software as well as customized machining strategies and properly selected machining parameters. Only by combining the two can the advantage of high-speed machining be made full use of. Compared to ordinary NC cutting, high-speed machining has special requirements for process strategies, CAM system and tool path. A complete tool path includes approaching/retracting tool, moving tool and tool path. Based on the above principles, a mould part is successfully processed using the PowerMILL software at the high-speed machining centre of DMG-DMU40T. The maximum hardness of the mould part is HRC50. There’s a 30 degree corner in the cavity with a transition radius of 3mm. The whole process can be divided into three stages: rough, semi-finish and finish machining and each stage involves the selection of tool path, the selection of tool, the selection of cutting parameters (including spindle speed, feed speed and depth of cut), and the application of PowerMILL specific machining methods (such as Race-line machining, rest roughing, automatic trochoidal machining, 3D offset finishing and etc).

Spiral Tool Path Planning Using Eccentric Parameters

2014 ◽  
Author(s):  
Baosu Guo ◽  
Qingjin Peng ◽  
Xiaosheng Cheng ◽  
Ning Dai
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Free Form ◽  
Tool Path Planning ◽  
Inverse Mapping ◽  
Machined Surface ◽  
Tool Paths ◽  
Spiral Tool Path ◽  
Free Form Surfaces ◽  
The Relationship

Free-form surfaces can be machined continuously with minimum tool retractions and at the high speed by following a spiral tool path. This paper presents an improved planning method of the spiral tool path using eccentric parameters for machining free-form surfaces. The relationship between a 3D machined surface and the 2D circular region is established through the conformal mapping. In order to generate an even path, eccentric parameters are used in 2D parametric circular regions to optimize the path interval. The proposed method produces planar spiral segments as a diagonal curve between every two adjacent parametric tool paths. A 2D spiral tool path is gained by linking spiral segments in sequence. Inverse mapping of the 2D spiral tool path onto the machined surface generates the 3D spiral tool path. The main processes of the proposed method include reducing dimensions of free-form surfaces, calculating the eccentric parametric tool path, and generating the planar diagonal spiral tool path. Some applications are used to verify the proposed methods. The proposed method allows the start point to be arbitrary and generates more even tool paths than the existing methods by introducing the mapping distortion.

scholarly journals Deflection Analysis of the Thin-Web Workpiece Structure Using Similarity Concept

2011 ◽  
Vol 337 ◽  
pp. 479-488
Author(s):  
Nurhaniza Mohamad ◽  
M.K.A.M. Arifin ◽  
Aidy Ali ◽  
Faizal Mustapha
Keyword(s):  
High Speed ◽  
High Performance ◽  
Tool Path ◽  
Dynamic Stiffness ◽  
Cutting Parameters ◽  
High Speed Machining ◽  
Workpiece Vibration ◽  
Deflection Analysis ◽  
Optimum Solution ◽  
Element Removal

The thin-web structure component is widely used in aviation and aerospace industries with the reason of light weight and high performance. However, the thin-web components are tending to deflect because of their poor rigidity and the effect of cutting force during cutting process. It is required to perform of high-speed machining that can remove the large number of material in a shorter time in order to allow machining of such structure. The performance of high-speed machining operation is restricted by the static and dynamic stiffness of the tool and part that can cause some problems such as regenerative chatter and ‘push-off’. The tool path plays an important function to avoid the problem occurs as it assists to reduce the workpiece vibration during machining. The optimization of tool path is done by determining the element removal sequences and the materials removal are implemented using milling cutter. The maximum deflection for each element removed is recorded in order to define the optimum solution of element removal sequences. The analysis shows that there are significant effects of workpiece stiffness with relation to the cutting parameters setting.

A Swept Ellipse Offsetting Approach for Three-Axis Sculptured Surface Tool Path Generation

2004 ◽  
Author(s):  
Peter Jang ◽  
James A. Stori
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Contact Point ◽  
Tool Path Generation ◽  
Sculptured Surface ◽  
Path Generation ◽  
Surface Machining ◽  
Tool Paths ◽  
Sculptured Surface Machining ◽  
Processing Techniques

This paper presents a new offsetting approach for tool path generation in three-axis sculptured surface machining. The approach generates tool paths with scallop, curvature, and force characteristics which make them suitable for high speed machining. An ellipse in the parametric space is used to approximate the intersection between the ball-end mill and the scallop surface for any cutter contact point on the surface. The envelope formed by these swept ellipses of varying dimension and orientation creates a constant scallop curve which is used to generate offset paths. The offset is developed incrementally, utilizing post-processing techniques to eliminate high-curvature regions in the trajectory. The offsetting approach can generate continuous spiraling trajectories which offer the benefit of minimal tool retractions. Results are shown for spiraling paths generated from both convex and non-convex boundaries.

A New Architecture of Tool Path Generation for Five-Axis Control Machining

2005 ◽  
Vol 291-292 ◽  
pp. 501-506 ◽  
Author(s):  
K. Nakamoto ◽  
K. Shirase ◽  
Akifumi Morishita ◽  
E. Arai ◽  
T. Moriwaki
Keyword(s):  
Machine Tool ◽  
Real Time ◽  
Manufacturing Systems ◽  
Tool Path ◽  
Cutting Parameters ◽  
Tool Paths ◽  
Nc Program ◽  
Digital Copy ◽  
Copy Milling ◽  
Five Axis

NC machine tools, which are widely employed in manufacturing systems, are basically driven by NC programs. However, it requires extensive amount of time and efforts to generate high quality tool paths before a machining operation. An NC program for five-axis control machining is more difficult to generate because the motion of machine tool is more complicated. In this paper, a new architecture is proposed to autonomously control the machine tool without an NC program for more rapid and flexible machining. A technique called digital copy milling is developed to generate the tool paths in real time based on the principle of copy milling. It means that the cutting parameters can be adaptively controlled in order to maintain stable cutting process and to avoid the cutting troubles. In the experimental verification, the improved digital copy milling system for five-axis control milling successfully detected and avoided tool collision in real-time.

Time-Efficient Trochoidal Tool Path Generation for Milling Arbitrary Curved Slots

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Ke Xu ◽  
Baohai Wu ◽  
Zhaoyu Li ◽  
Kai Tang
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Removal Rate ◽  
Machining Efficiency ◽  
Machining Time ◽  
Tool Paths ◽  
Engagement Angle ◽  
New Type ◽  
The Given ◽  
Slot Cutting

Trochoidal (TR) tool paths have been a popular means in high-speed machining for slot cutting, owing to its unique way of cyclically advancing the tool to avoid the situation of a full tool engagement angle suffered by the conventional type of slot cutting. However, advantageous in lowering the tool engagement angle, they sacrifice in machining efficiency—to limit the tool engagement angle, the step distance has to be carefully controlled, thus resulting in a much longer total machining time. Toward the objective of improving the machining efficiency, in this paper, we propose a new type of TR tool path for milling an arbitrary curved slot. For our new type of TR tool path, within each TR cycle, rather than moving circularly, the tool moves in a particular way such that the material removal rate is maximized while the given maximum engagement angle is fully respected. While this type of TR tool path works perfectly only for circular slots (including straight ones), by means of an adaptive decomposition and then a novel iso-arc-length mapping scheme, it is successfully applied to any general arbitrarily curved slot. Our experiments have confirmed that, when compared with the conventional TR tool paths, the proposed new type of TR tool path is able to significantly reduce the total machining time by as much as 25%, without sacrificing the tool wear.

scholarly journals Spiral Tool Path Generation Method on Mesh Surfaces Guided by Radial Curves

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Jinting Xu ◽  
Yukun Ji ◽  
Yuwen Sun ◽  
Yuan-Shin Lee
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Interpolation Method ◽  
Tool Path Generation ◽  
Numerical Control ◽  
Path Generation ◽  
Cnc Milling ◽  
Tool Paths ◽  
Spiral Tool Path ◽  
Mesh Surface

This paper presents a new spiral smoothing method to generate smooth curved tool paths directly on mesh surfaces. Spiral tool paths are preferable for computer numerical control (CNC) milling, especially for high-speed machining. At present, most spiral tool path generation methods aim mainly for pocketing, and a few methods for machining complex surface also suffer from some inherent problems, such as selection of projecting direction, preprocessing of complex offset contours, easily affected by the mesh or mesh deformation. To address the limitations, a new spiral tool path method is proposed, in which the radial curves play a key role as the guiding curves for spiral tool path generation. The radial curve is defined as one on the mesh surface that connects smoothly one point on the mesh surface and its boundary. To reduce the complexity of constructing the radial curves directly on the mesh surface, the mesh surface is first mapped onto a circular region. In this region, the radial lines, starting from the center, are planned and then mapped inversely onto the mesh surface, thereby forming the desired radial curves. By traversing these radial curves using the proposed linear interpolation method, a polyline spiral is generated, and then, the unfavorable overcuts and undercuts are identified and eliminated by supplementing additional spiral points. Spline-based technique of rounding the corners is also discussed to smooth the polyline spiral, thereby obtaining a smooth continuous spiral tool path. This method is able to not only greatly simplify the construction of radial curves and spiral tool path but also to have the ability of processing and smoothing complex surfaces. Experimental results are presented to validate the proposed method.

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