Iso-phote Based Tool-path Generation for Machining Free-form Surfaces

1999 ◽  
Vol 121 (4) ◽  
pp. 656-664 ◽  
Author(s):  
Zhonglin Han ◽  
Daniel C. H. Yang
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
Free Form ◽  
Normal Vector ◽  
Path Generation ◽  
Reference Vector ◽  
Tool Paths ◽  
Offset Curves ◽  
Fixed Reference ◽  
Free Form Surfaces

This paper presents a novel approach for generating efficient tool paths in machining free-form surfaces. Concept of iso-phote is used to facilitate tool-path generation. An iso-phote is defined as a region on a surface where the normal vector does not differ by more than a prescribed angle from a fixed reference vector. The boundary curves of the iso-phote, called iso-inclination curves, are numerically generated and are served as the initial master tool paths. These iso-inclination curves are then projected to a 2D plane which is perpendicular to the fixed reference vector. 2D curve offsetting of the projected iso-inclination curve is then performed. The resulted 2D offset curves are projected back to 3D surface to form final tool paths. The resulted tool paths can guarantee the satisfaction of machining tolerance requirements. A comparison study of this iso-phote based machining with the conventional iso-parametric machining and the iso-planar machining shows favorite result for the new approach.

Adaptive iso-planar tool path generation for machining of free-form surfaces

2003 ◽  
Vol 35 (2) ◽  
pp. 141-153 ◽  
Author(s):  
S. Ding ◽  
M.A. Mannan ◽  
A.N. Poo ◽  
D.C.H. Yang ◽  
Z. Han
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
Free Form ◽  
Path Generation ◽  
Free Form Surfaces

Tool Path Generation Method for High-Quality Machining of Free-Form Surfaces

2020 ◽  
Author(s):  
Yuki Takanashi ◽  
Hideki Aoyama
Keyword(s):  
Tool Path ◽  
High Accuracy ◽  
Tool Path Generation ◽  
Free Form ◽  
Machining Accuracy ◽  
Path Generation ◽  
High Quality ◽  
Nc Program ◽  
Free Form Surface ◽  
Free Form Surfaces

Abstract Machining data (NC program) is generated by a CAM system, which generates the tool path from the target shape as a plane approximation surface instead of a free-form surface. Owing to this plane approximation, machining accuracy is reduced. In this paper, we propose a method to process the shape with high accuracy by defining the areas where accuracy is not required as a plane approximation surface and defining the part where accuracy is required as free-form surfaces.

Tool path generation for pattern sculpting on free-form surfaces

2012 ◽  
Vol 67 (9-12) ◽  
pp. 2469-2476 ◽  
Author(s):  
Jinting Xu ◽  
Xiangkui Zhang ◽  
Shunke Wang ◽  
Jianhuang Wu
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
Free Form ◽  
Path Generation ◽  
Free Form Surfaces

Tool Path Generation for Machining Shrouded Turbine Blisk

2004 ◽  
Author(s):  
Xiang Wu ◽  
Wansheng Zhao ◽  
R. Du
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
New Method ◽  
Free Form ◽  
Machining Accuracy ◽  
Geometrical Shape ◽  
Path Generation ◽  
Simultaneous Control ◽  
Turbine Blisk ◽  
Free Form Surfaces

Shrouded turbine blisk is an important component for liquid-propellant rocket engine, airplane engine and some other high-power turbine machines. It is made from high-temperature alloy (e.g., nickel-base alloy and titanium alloy) and hence, is difficult to machine. In addition, its geometrical shape is complicated involving many semi-enclosed, twisted, free-form surfaces. In order to ensure the best performance, its dimension accuracy is very demanding. For the moment, an effective way to manufacture shrouded turbine blisk is Electrical Discharge Machining (EDM) using form tools (form electrodes). However, owing to its complicated geometry, existing commercial CAM systems cannot generate the interference-free tool path for it. In this paper, a new tool path generation method is presented. The new method is base on the quadratic programming and CNC multi-axis simultaneous control. It generates tool path in two steps. First, a feasible zone is generated by coarse search, which gives an elementary path for form tool feed. Then, within the feasible zone the actual NC tool path is found by fine search through CNC multi-axis simultaneous control simulation. In practice, a form tool follows the interference-free tool path moving into the twisted passages of blisk for machining, while the blisk is turning by a CNC turntable. The new method is validated experimentally. Compared to the existing methods, it can obtain high machining efficiency and high machining accuracy. Experimental results indicate that the new method is accurate. This new method can also be applied to many other machining applications involving complicated geometrical shape.

scholarly journals Tool path generation for milling of free form surfaces with feed rate scheduling

2015 ◽  
Vol 43 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Goran Mladenovic ◽  
Ljubodrag Tanovic ◽  
Kornel Ehmann
Keyword(s):  
Feed Rate ◽  
Tool Path ◽  
Tool Path Generation ◽  
Free Form ◽  
Path Generation ◽  
Rate Scheduling ◽  
Free Form Surfaces

A Higher-Order Formula of Path Interval for Tool-Path Generation

2011 ◽  
Vol 5 (5) ◽  
pp. 663-668 ◽  
Author(s):  
Toshiyuki Obikawa ◽  
◽  
Tsutomu Sekine ◽  
Keyword(s):  
Surface Roughness ◽  
Fourth Order ◽  
Tool Path ◽  
Order Term ◽  
Computational Cost ◽  
Tool Path Generation ◽  
Free Form ◽  
Path Generation ◽  
Scallop Height ◽  
Free Form Surfaces

This paper presents a novel fourth-order formula for determining path intervals and comprehensively considers path interval formulas. In tool-path generation, a path interval is generally formulated as a scallopheight polynomial. Controlling scallop height in mechanical machining improves surface roughness or machining efficiency. We derived a novel fourth-order formula for determining path intervals after reviewing several formulas, then compared formulas. This clarified the differences between path interval formulas with graphic evidence. In micromechanical machining, an approximate expression has an advantage in computational cost but a disadvantage in accuracy. Although our proposed formula includes the fourth order-term scallop height, it requires low computational cost and can be applied to the determining path intervals for free-form surfaces in micromechanical machining. In addition, a correction method of the surface roughness on a free-form surface measured with a profilometer was proposed.

Tool-Path Generation in Three-Axis Machining From Scanned Data of Physical Models by Using Filleted Endmills

2000 ◽  
Author(s):  
Cheng-Ming Chuang ◽  
Chun-Yan Chen ◽  
Hong-Tzong Yau
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
Physical Models ◽  
Free Form ◽  
Cad Model ◽  
Path Generation ◽  
Location Data ◽  
Tool Paths ◽  
Measuring Machine ◽  
Cutter Location Data

Abstract NC tool-path is usually generated by sweeping parametric surfaces of a CAD model. In modern design, free-form or sculptured surfaces are increasingly popular in representing complex geometry for aesthetic or functional purposes. Traditionally, a prototype is realized by machining the workpiece using the NC codes generated from a CAD model. The machined part can then be compared with the CAD model by measurement using a coordinate measuring machine. Presented in this paper is a reverse engineering approach to generating interference free tool-paths in three-axis machining from scanned data of physical models. There are two steps in this procedure. First, a physical model is scanned by 3D digitizers and multiple data sets are obtained of the complex model. A surface registration algorithm is proposed to align and integrate those data to construct a complete 3D data set. We use least distance method to determine the connecting sequence of the neighboring points, such that the scanned data are converted into triangular polygons. Tool-paths are then generated from the tessellated surfaces. Using the Z-map method we calculate interference-free cutter-location data relative to the vertex, edges and planes of those triangles. The algorithms for tool-path generation are usually different for cutters of various geometry. Some algorithms found in literature require complex numerical calculations and are time consuming. In this paper, an efficient algorithm is developed to calculate interference-free cutter-location data by easy geometric reasoning without complex computation. The robust method is suitable for generally used cutters such as ball, flat and filleted endmills and the time taken to obtain full tool-paths of compound surfaces is short. Some real applications are presented to validate the proposed approach.

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