Proposal of a Tool Path Generation Method to Ensure Workpiece Stiffness for Efficient Rough Machining

2020 ◽  
Author(s):  
Maho Kumanotani ◽  
Hitoshi Kusino ◽  
Keiichi Nakamoto
Keyword(s):  
Topology Optimization ◽  
Complex Shape ◽  
Tool Path ◽  
Machining Parameters ◽  
Rough Machining ◽  
Tool Paths ◽  
Design Variables ◽  
Hand Tool ◽  
Complex Parts ◽  
Cam Software

Abstract Recently, the demand of complex shape parts has increased in the aircraft and medical industries. In these parts machining, the displacement and vibration of workpiece that strongly affect the machining efficiency are induced due to the heavy change of the unmachined workpiece shape and stiffness during rough machining. However, it is difficult to automatically determine machining parameters of operation planning by using a commercial CAM software because there is a large number of combinations. Therefore, in order to improve the efficiency of complex parts machining, the authors proposed a determination method of workpiece shapes during rough machining based on topology optimization relevant to maximizing static stiffness. On the other hand, tool paths that directly affect the workpiece stiffness are not generated automatically to create the calculated workpiece shapes in the previous study. From these reasons, this study proposes a generation method of tool paths by using design variables obtained through the calculation of topology optimization. The tool paths are simply generated based on design variables and enables to ensure the workpiece stiffness during rough machining because design variables are strongly related to the objective function. By conducting a machining experiment assuming complex parts machining, it is confirmed that the proposed method has a potential to realize efficient rough machining.

Research on Chamfer Software of Complex Parts

2013 ◽  
Vol 631-632 ◽  
pp. 1335-1341
Author(s):  
Shi Yong ◽  
Wen Tao Liu
Keyword(s):  
3D Model ◽  
Tool Path ◽  
Machining Parameters ◽  
Cad Cam ◽  
Programming Software ◽  
A Chain ◽  
Definition Of ◽  
Complex Parts ◽  
Cam Software ◽  
Location Point

In order to meet the needs of enterprises for chamfering complex parts, based on the customization of commercial CAD/CAM software, chamfer programming software is developed. According to user’s machining demands for a part, a chain of edges of a part is extracted from its 3D model. With preprocessing of the chain of edges, the continuity of the chain is estimated, and the start and end point of those edges are automatic obtained. Furthermore, with human-machine dialogue, machining parameters is set by users. By definition of the primary and secondary surfaces of the chain of edges, and interpolation of the edges, the positions of cutter location point and postures of cutter are calculated. Finally the interference of tool path is checked, and tool path is simulated. The software solves the programming problem of chamfering complex parts.

A cutting sequence optimization method based on tabu search algorithm for complex parts machining

2018 ◽  
Vol 233 (3) ◽  
pp. 745-755 ◽  
Author(s):  
Chuanwei Zhang ◽  
Feiyan Han ◽  
Wu Zhang
Keyword(s):  
Tabu Search ◽  
Tool Path ◽  
Search Algorithm ◽  
Optimization Method ◽  
Traveling Salesman ◽  
Tabu Search Algorithm ◽  
Rough Machining ◽  
Sequence Optimization ◽  
Cutting Sequence ◽  
Complex Parts

Defining the cutting sequence of each cutter scientifically in the process of removing the allowance has an important influence on the machining efficiency for complex parts, which have multiple machining features. In order to satisfy the needs of high efficiency for rough machining, after determining the tool path of the machining region, a cutting sequence optimization method based on the tabu search algorithm is presented to define the cutting order in rough machining of complex parts. First, a cutting sequence optimization mathematical model is established, which relates to the shortest total length of the tool path. Second, through the problem analysis, the cutting sequence optimization model is converted into an open and constrained traveling salesman problem. And then, the optimization model is solved by dealing with an open and constrained traveling salesman problem using the tabu search algorithm. Finally, the optimal cutting sequence of machining a casing part is calculated, and a simulation and experiment are carried out. The result shows that the optimization approach presented in this article can optimize the cutting sequence and cutter position of advance and retract. Compared with the non-optimized cutting sequence method, the total length of tool path is reduced by 16.7%, the cutter lifting times are reduced to 26, and the efficiency is increased by 21.62%.

ROUGH MACHINING FOR MULTI-SCULPTURED SURFACES

1999 ◽  
Vol 23 (2) ◽  
pp. 275-286
Author(s):  
A. Vafaeesefat ◽  
H.A. EIMaraghy
Keyword(s):  
Cutting Planes ◽  
Tool Path ◽  
Tool Path Generation ◽  
Parallel Projection ◽  
Geometric Description ◽  
Sculptured Surfaces ◽  
Rough Machining ◽  
Tool Paths ◽  
Rough Milling ◽  
Bounding Surfaces

This paper present a method to generate 3-axis NC programs for rough milling processes. A raster digitizing of the solid volume delimitated by sculptured surfaces to be machined is first created. This is accomplished by using the so-called Z-buffer created from a parallel projection of all surfaces. Conventional rendering software can be used to generate the Z-buffer. This volume is transformed into a 3-D mesh composed of “empty”, “full”, and “mixed” blocks. Machining is preformed from top to bottom in a sequence of horizontal cutting planes. At each level of planar machining, spiral routines are used to generate the tool path. The proposed method is valid for generating tool paths for general cavities bounded by arbitrary surfaces. One of the notable advantages of the proposed method is that the tool path generation is independent from the geometric description of bounding surfaces. An example is used to illustrate the approach and its advantages.

A high-efficiency rough milling strategy for mould core machining

2003 ◽  
Vol 217 (3) ◽  
pp. 335-348 ◽  
Author(s):  
K W Chan ◽  
W K Chiu ◽  
S T Tan ◽  
T N Wong
Keyword(s):  
Convex Hull ◽  
Tool Path ◽  
High Efficiency ◽  
Core Layer ◽  
Layer By Layer ◽  
Rough Machining ◽  
Productivity Improvement ◽  
Tool Paths ◽  
Contour Parallel Tool Path ◽  
Rough Milling

Increasing the efficiency of rough machining operations can produce significant productivity improvement in mould and die making because most of the metal is removed in the roughing stage. In this paper, a high-efficiency 2.5-dimensional rough milling strategy for mould core machining is presented. The strategy consists of three different tool paths. The first tool path is generated on the basis of the convex hull boundary of a machining region. Owing to the absence of concave tool path segments, the convex hull based tool path can eliminate the chip load fluctuation problem encountered in corner cutting. The second tool path is an enhanced unidirectional straight-line tool path, which has the virtue of maintaining a steady cutting resistance throughout. The large staircases left behind by these two tool paths are refined by using the third tool path which is a contour-parallel tool path that cuts the mould core layer by layer in an upward manner. After applying these three tool paths, the stock material left on the mould core surface can be post-processed by the subsequent finish milling operation. A case study is illustrated to demonstrate the practicality of the presented rough milling strategy.

A Generic, Geometric Approach to Accurate Machining-Error Predictions for 3-Axis CNC Milling of Sculptured Surface Parts: Part II — Applications and Analysis

2006 ◽  
Author(s):  
Zezhong C. Chen ◽  
Wei Cai
Keyword(s):  
Tool Path ◽  
Geometric Approach ◽  
Sculptured Surface ◽  
Cnc Milling ◽  
Sculptured Surfaces ◽  
Machining Error ◽  
Tool Paths ◽  
Machining Errors ◽  
Tool Surface ◽  
Cam Software

As sculptured surfaces are widely used in mechanical design, machining sculptured surface parts accurately is highly demanded in industry; however, it is quite challenging to meet their demand. Due to the geometric complexity of these surfaces, the tool-surface geometric mismatch always causes machining errors when the tool cuts along the tool paths. To prevent surface gouging, where the machining error is greater than the part tolerance, state-of-the-art CAM software usually determines cutter contact (CC) points on the tool paths first, and then simulates the machining to check the errors caused by this tool-surface mismatch. If surface gouging occurs, the CC points are adjusted using the CAM software. But this established method is quite time consuming and sometimes ineffective. To overcome these problems, a new system, based on the accurate predictions of machining errors, is proposed in this research paper for the optimization of CC points on the tool paths. First, two established CC point generation methods, the chordal deviation method and the circular arc approximation method, are introduced; and their limitations are addressed. Second, a sensitivity study of the machining errors with respect to the cutting tools is conducted. Then a system implementing the generic, geometric approach to accurate machining-error predictions is proposed to optimize CC points on the tool paths. Finally, this CC point optimization system is applied to two practical parts to demonstrate its advantages over the two established methods. This proposed work provides a profound understanding of the machining errors caused by the tool-surface mismatch and contributes to tool path planning for 3-axis CNC milling of sculptured surface parts.

Additive Manufacturing Bead Deposition Based Rotary Tool Path Applications

2018 ◽  
Author(s):  
Ruth Jill Urbanic ◽  
Bob Hedrick
Keyword(s):  
Additive Manufacturing ◽  
Tool Path ◽  
Thermal Spraying ◽  
Direct Energy Deposition ◽  
Tool Paths ◽  
Rotary Tool ◽  
Rotationally Symmetric ◽  
Direct Energy ◽  
Cad Cam ◽  
Cam Software

Additive manufacturing layer-based solution approaches have been applied for several technologies and systems. Process planning solutions are being developed for planar applications, but rotary applications can benefit from an additive manufacturing ‘rotary layering’ strategy as well. There are systems that have been developed to coat pipes and other rotationally symmetric components, and there are multi-axis applications that would require rotary-like tool paths. Developing and exploring additive rotary tool path applications is the focus of this research. These initial solutions will be applicable for direct energy deposition and thermal spraying models. AM rotary proof of concept tool paths are developed using a commercial CAD/CAM software, and a software development kit (SDK). Selected case studies are presented, with varying levels of geometric complexity.

Optimum end milling tool path and machining parameters for micro Laval nozzle manufacturing

2015 ◽  
Vol 231 (10) ◽  
pp. 1703-1712 ◽  
Author(s):  
Yukui Cai ◽  
Zhanqiang Liu ◽  
Zhenyu Shi ◽  
Qinghua Song ◽  
Yi Wan
Keyword(s):  
Surface Roughness ◽  
Laval Nozzle ◽  
Tool Path ◽  
Cutting Tool ◽  
End Milling ◽  
Cutting Parameters ◽  
Machining Parameters ◽  
Performance Parameters ◽  
Tool Paths ◽  
Milling Tool

Cutting tool path has significant effects on the performance of micro nozzles manufactured by micro machining. Different tool paths induced different directions of surface roughness. As for it, the manufacturers need to obtain optimal cutting tool path and cutting parameters. In this article, optimum machining parameters for the fabrication of micro Laval nozzle with two different end milling tool paths are presented. First, surface roughness models for different types of cutting tool paths are proposed. A case of machined nozzle surface is then given to verify the applicability of the developed roughness model. Second, theoretical profile geometries for the Laval nozzle to be manufactured are designed. Third, the influences of surface roughness on the nozzle performance parameters including total pressure, average outlet velocity and thrust are investigated through computational fluid dynamic analysis. Simulated performance parameters are contrasted with their theoretical values. It is found that for different tool paths, the nozzle of axial tool path has larger total pressure and average outlet velocity than that of circular tool path. Moreover, with surface roughness increasing, thrust decreases obviously when surface roughness Rz is larger than 4.8 μm. Micro end milling experiments based on axial tool path are then performed, and the optimum cutting parameters are obtained. Finally, a nozzle was manufactured with the axial tool path as well as the optimized cutting parameters.

scholarly journals Precision Sculptured Surface CNC Machining Using Cutter Location Data

2016 ◽  
Vol 686 ◽  
pp. 224-233
Author(s):  
Nikolaos A. Fountas ◽  
Nikolaos M. Vaxevanidis ◽  
Constantinos I. Stergiou ◽  
Redha Benhadj-Djilali
Keyword(s):  
Tool Path ◽  
Low Cost ◽  
Cnc Machining ◽  
Sculptured Surface ◽  
Sculptured Surfaces ◽  
Rough Machining ◽  
Machining Error ◽  
Location Data ◽  
Tool Paths ◽  
Cutter Location Data

Industrial parts with sculptured surfaces are typically, manufactured with the use of CNC machining technology and CAM software to generate surface tool paths. To assess tool paths computed for 3-and 5-axis machining, the machining error is evaluated in advance referring to the parameter controlling the linearization of high-order curves, as well as the scallop yielded as a function of radial cutting engagement parameter. The two parameters responsible for the machining error are modeled and corresponding cutter location data for tool paths are utilized to compare actual trajectories with theoretical curves on a sculptured surface assessing thus the deviation when virtual tools are employed to maintain low cost; whilst ensuring high precision cutting. This operation is supported by applying a flexible automation code capable of computing the tool path; extracting its CL data; importing them to the CAD part and finally projecting them onto the part’s surface. For a given tolerance, heights from projected instances are computed for tool paths created by changing the parameters under a cutting strategy, towards the identification of the optimum tool path. To represent a global solution rough machining is also discussed prior to finish machining where the new proposals are mainly applied.

Dynamic In-Process Stock Based Tool Path Generation for High Surface Finish Rough Machining

2013 ◽  
Vol 567 ◽  
pp. 59-65
Author(s):  
Song Lin Ding ◽  
John P.T. Mo ◽  
Daniel Yang
Keyword(s):  
Surface Finish ◽  
Process Model ◽  
Tool Path ◽  
High Surface ◽  
Tool Path Generation ◽  
Path Generation ◽  
Rough Machining ◽  
Machining Time ◽  
Additional Tool ◽  
Tool Paths

This paper presents a new tool path generation strategy for rough machining based on the dynamic in-process stock model of the workpiece. Compared to conventional roughing method, the new tool paths result in a better surface finish but consume the same machining time. The cutter locations in the tool path are determined by removing the peak portion of the residual materials on the stock. The geometric information of remaining stocks is updated dynamically in the in-process model once each cutting pass is completed. The overall machining time is no longer than the conventional method since no additional tool paths are added. The proposed method was implemented in Catia and has been validated by simulation and cutting tests with flat end and ball nose cutters on a 3-axis CNC milling machine.

Optimisation of tool path for wood machining on CNC machines

2016 ◽  
Vol 231 (1) ◽  
pp. 72-87 ◽  
Author(s):  
A Petrovic ◽  
L Lukic ◽  
S Ivanovic ◽  
A Pavlovic
Keyword(s):  
Tool Wear ◽  
Cutting Force ◽  
Tool Path ◽  
Cutting Parameters ◽  
Machining Process ◽  
Machining Parameters ◽  
Wood Processing ◽  
Tool Paths ◽  
Radial Depth ◽  
Wood Machining

Peripheral pocket or contour milling in wood machining, using flat end milling tool, can be performed with different tool paths. Technology designers of multi axis CNC wood machining use their experience and intuition to choose some of the options offered by CAM systems that determine the final shape of tool path, thus the generated tool path largely depend on individual judgment. Minimum cutting force, maximum dynamic stability of the process and minimum tool wear are achieved, or some other technological requirements are met, by using optimal tool path. Tool path optimisation is based on analysis of possible tool paths and determination of cutting parameters which are dependable of chosen tool path and are affecting the main wood processing factors. Axial and radial depth of cut, engagement angle, feed and feed rate profile are identified as key parameters dependable of tool path, and their values and variations along the tool path influence the cutting speed, tool wear and cutting force. Knowledge of values and changes of those key machining parameters along the tool path is necessary for simulation and monitoring of the main cutting factors during the wood machining process. NC code transformation methodology and generation of tool path parameters necessary for calculating all elements needed for tool movement simulation from given NC programs are shown. Blank and tool mathematical description are used with tool movement information for simulation of wood machining process. Simulation of cutting parameters and their variation along the tool path, presented in this paper, can be used as bases for development of methodology for choosing the most adequate tool path for wood machining of given contour considering minimum cutting force and cutting force variation, minimum tool wear, maximum productivity or some other criteria.

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