scholarly journals Machining Time Reduction by Tool Path Modification to Eliminate Air Cutting Motion for End Milling Operation

2020 ◽  
Vol 14 (3) ◽  
pp. 459-466 ◽  
Author(s):  
Isamu Nishida ◽  
◽  
Keiichi Shirase
Keyword(s):  
Tool Path ◽  
End Milling ◽  
Axial Direction ◽  
Contour Line ◽  
Product Model ◽  
Machining Time ◽  
High Productivity ◽  
Product Surface ◽  
Path Modification ◽  
Tool Path Modification

A method to uniquely calculate the tool path and to modify the tool path during air cutting motion to reduce the machining time is proposed. This study presents a contour line model, in which the product model is minutely divided on a plane along an axial direction, and the contour line of the cross-section of the product is superimposed. A method is then proposed to calculate the tool position according to the degree of interference between the product surface and the tool. Furthermore, this study proposes a technique to reduce the machining time by tool path modification during air cutting motion. This is determined by the geometric relationship between the product surface and the tool, and not based on cutting simulations. A cutting experiment was conducted to validate the effectiveness of the proposed method. Based on the results, it was confirmed that the difference in machining time between the tool path with modification and the tool path without modification was large. Moreover, the machining time was significantly reduced by the tool path modification. The results showed that the proposed method has good potential to perform customized manufacturing, and to realize both high productivity and reliability in machining operation.

Automated Tool Path Generation for End-Milling Operation Using CAD Model in STL Format

2021 ◽  
Author(s):  
Isamu Nishida ◽  
Keiichi Shirase
Keyword(s):  
Tool Path ◽  
End Milling ◽  
Mesh Size ◽  
Triangular Mesh ◽  
Contour Line ◽  
Cad Model ◽  
Product Model ◽  
Convex Shape ◽  
Geometrical Feature ◽  
3D Cad

Abstract A method to extract the machining region from 3D CAD model in STL (Standard Triangulated Language) format and automatically generate tool path is proposed. At first, this study proposes a method to extract the machining region and obtain the geometrical feature such as convex shape or concave shape from only the 3D CAD model in STL format. The STL format has only triangular mesh data and drops all the information which is necessary to extract the removal volume for machining and the geometrical characteristics. Furthermore, the triangular mesh size is non-uniform. Then, the contour line model, in which the product model is minutely divided on the plane along any one axial direction and represented by points at intervals below the indicated resolution obtained from the contour line of the cross section of the product, is proposed. Subsequently, this study proposes a method to determine the machining conditions for each extracted machining region and automatically generate tool path according to the obtained geometrical feature of the machining region.

Development of CAM Software to Achieve Automated NC Program Generation: Application to Machining From Near Net Shape Material

2020 ◽  
Author(s):  
Isamu Nishida ◽  
Keiichi Shirase
Keyword(s):  
Axial Direction ◽  
Product Model ◽  
High Productivity ◽  
Tool Paths ◽  
Contour Lines ◽  
Nc Program ◽  
Product Surface ◽  
Good Potential ◽  
Near Net Shape

Abstract A method to automatically calculate tool paths and apply to machining from near net shape material is proposed. At first, this study proposes a contour line model, in which the product model is minutely divided on the plane along any one axial direction and the contour lines to show the cross section of the product is superimposed. Subsequently, this study proposes a method to calculate the tool positions according to the interference amount between product surface and tool. Furthermore, this study proposes the method to calculate tool paths for near net shape material. The case study was conducted to validate the effectiveness of the proposed method. As the result of this case study, it was confirmed that the proposed method can automatically generate the tool paths for near net shape. The machining efficiency from near net shape material will be better than that from box shape material. The results showed that the proposed method has good potential to perform customized manufacturing, and realize both high productivity and reliability in machining operation.

scholarly journals Automated Process Planning System for End-Milling Operation by CAD Model in STL Format

2021 ◽  
Vol 15 (2) ◽  
pp. 149-157
Author(s):  
Isamu Nishida ◽  
◽  
Keiichi Shirase
Keyword(s):  
Tool Path ◽  
End Milling ◽  
Mesh Size ◽  
Triangular Mesh ◽  
Contour Line ◽  
Planning System ◽  
Cad Model ◽  
Product Model ◽  
3D Cad ◽  
Geometrical Features

A method for extracting the machining region from a 3D CAD model in Standard Triangulated Language (STL) format and automatically generating a tool path is proposed. First, a method is proposed for extracting the machining region and obtaining the geometrical features such as a convex or concave shape from only the 3D CAD model in STL format. The STL format uses only triangular mesh data and drops all information, which is necessary for extracting the removal volume for the machining and geometrical characteristics. Furthermore, the triangular mesh size is non-uniform. A contour line model is proposed in which the product model is minutely divided on the plane along any one axial direction and is represented by points at intervals below the indicated resolution obtained from the contour line of the cross section of the product. Subsequently, a method is proposed to determine the machining conditions for each extracted machining region and automatically generate a tool path according to the geometrical features of the machining region obtained. A machining experiment was conducted to validate the effectiveness of the proposed method. As a result of the machining experiment, it was confirmed that the tool path automatically generated from the 3D CAD model in STL format can be machined without any problems and with a practical level of accuracy.

A Tool Path Modification Approach to Cutting Engagement Regulation for the Improvement of Machining Accuracy in 2D Milling With a Straight End Mill

2007 ◽  
Vol 129 (6) ◽  
pp. 1069-1079 ◽  
Author(s):  
M. Sharif Uddin ◽  
Soichi Ibaraki ◽  
Atsushi Matsubara ◽  
Susumu Nishida ◽  
Yoshiaki Kakino
Keyword(s):  
Cutting Force ◽  
Case Studies ◽  
Tool Path ◽  
Free Form ◽  
Geometric Accuracy ◽  
End Mill ◽  
Workpiece Surface ◽  
Engagement Angle ◽  
Path Modification ◽  
Tool Path Modification

In two-dimensional (2D) free-form contour machining by using a straight (flat) end mill, conventional contour parallel paths offer varying cutting engagement with workpiece, which inevitably causes the variation in cutting loads on the tool, resulting in geometric inaccuracy of the machined workpiece surface. This paper presents an algorithm to generate a new offset tool path, such that the cutting engagement is regulated at a desired level over the finishing path. The key idea of the proposed algorithm is that the semi-finish path, the path prior to the finishing path, is modified such that the workpiece surface generated by the semi-finish path gives the desired engagement angle over the finishing path. The expectation with the proposed algorithm is that by regulating the cutting engagement angle along the tool path trajectory, the cutting force can be controlled at any desirable value, which will potentially reduce variation of tool deflection, thus improving geometric accuracy of machined workpiece. In this study, two case studies for 2D contiguous end milling operations with a straight end mill are shown to demonstrate the capability of the proposed algorithm for tool path modification to regulate the cutting engagement. Machining results obtained in both case studies reveal far reduced variation of cutting force, and thus, the improved geometric accuracy of the machined workpiece contour.

Constant Scallop-height Machining of Free-form Surfaces

1994 ◽  
Vol 116 (2) ◽  
pp. 253-259 ◽  
Author(s):  
K. Suresh ◽  
D. C. H. Yang
Keyword(s):  
Tool Path ◽  
End Milling ◽  
Free Form ◽  
Machining Time ◽  
Scallop Height ◽  
Location Data ◽  
Tool Paths ◽  
Novel Approach ◽  
Constant Scallop Height ◽  
Free Form Surfaces

A novel approach for the NC tool-path generation of free-form surfaces is presented. Traditionally, the distance between adjacent tool-paths in either the Euclidean space or in the parametric space is kept constant. Instead, in this work, the scallop-height is kept constant. This leads to a significant reduction in the size of the CL (cutter location) data accompanied by a reduction in the machining time. This work focuses on the zig-zag (meander) finishing using a ball-end milling cutter.

Effect of Feed Rate, Tool-Path and Step over on Geometric Accuracy of Freeform Surfaces when 3 Axis CNC Milling

2019 ◽  
Vol 889 ◽  
pp. 107-114
Author(s):  
Quy Hoang Van ◽  
Tuyen Bui Ngoc
Keyword(s):  
Feed Rate ◽  
Tool Path ◽  
End Milling ◽  
Cnc Milling ◽  
Sculptured Surfaces ◽  
Machining Time ◽  
Freeform Surfaces ◽  
Ball End Milling ◽  
Cad Cam ◽  
Step Over

The use of freeform (sculptured) surfaces in the product design process is accelerating at an exponential rate driven by functional as well as esthetics demands. CAD/CAM software is a must in their design are relatively well-covered, issues still remain when it comes to the actual manufacture of freeform surfaces. The major issues are related to the chosen feed rate, toolpaths and step over that would assure the required surface quality, the minimization of the total machining time, etc. This research presents an experimental study to define the effects of machining’s parameters (including: feed rate; toolpath and step over) for CNC 3-axis ball end milling process. The result shows a model for cutting is formulated and incorporated into the parameters of machining that is compatible with all CAD/CAM systems. This result can be used to choose parameters of optimum including federate, toolpath and step over when machining of other freeform surfaces. Keywords: Freeform surface; tool path; ball end milling

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