A Line and Arc Transition Tool Radius Compensation Algorithm for Convex Contour

2012 ◽  
Vol 542-543 ◽  
pp. 1167-1171
Author(s):  
Chun Wang ◽  
Sheng Lin ◽  
Quan Hai Peng
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Cnc Machining ◽  
Work Piece ◽  
Sharp Corner ◽  
Machining Time ◽  
Tool Paths ◽  
Long Time ◽  
Tangent Direction ◽  
Radius Compensation

Tool radius compensation is necessary to CNC machining. However, B tool radius compensation leads to work piece burning at the sharp corner of convex contour because of the long time contacts between the work piece and tool, and C tool radius compensation frequently changes machining feed rate for its broken line tool path. This paper presents a novel tool radius compensation method suitable for high speed machining of convex contour, which have the advantages of both B and C tool radius compensation. It uses compound transition with line and arc between the adjacent blocks of CNC program. The offset tool paths of the adjacent blocks extend a small line segment respectively along their tangent direction, then insert an arc between the end points of the two extended line segments. The results of simulation and experiments show that the machining quality of the sharp corner of convex contour is improved and the machining time is shorter than C tool radius compensation.

A Novel Automatic Feedrate Adjustment Method for Die-Cavity Roughing

2005 ◽  
Vol 291-292 ◽  
pp. 625-630
Author(s):  
Min Jie Wang ◽  
Y.J. Cai ◽  
W.G. Yan
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Orthogonal Cutting ◽  
Cnc Machining ◽  
Surface Model ◽  
Machining Time ◽  
Surface Machining ◽  
Cutter Deflection ◽  
Sculptured Surface Machining ◽  
Volumetric Models

Sculptured surface machining is a critical process commonly used in die and mold industries. Since there is a lack of scientific tools in practical process planning stages, feedrates of CNC machining are selected based on previous experiences. In the selection of feedrate, the feedrate is set an individual conservative constant value all along the die cavity roughing processes in order to avoid undesirable results such as chipping, cutter breakage or over-cut due to excessive cutter deflection. Usually, volumetric models or vector force models used for optimizaton of feedrates must be created to get the variable feedrates along the tool path. Considering the die cavity roughing being a 2.5D cutting, a novel cutting force surface model is created based on orthogonal cutting tests to adjust the feedrates. The model is tested by a typical die-cavity roughing, thinning down machining time and balanced cutting-load can be attained. The presented feedrate scheduling characterized by balancing the cutting-loads in die-cavity roughing will be more significative in high speed machining.

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.

Tool Path Optimization Based on the Constrain of Radial Cutting Depth in High Speed Milling

2011 ◽  
Vol 314-316 ◽  
pp. 1734-1739
Author(s):  
Kai Zhu Li ◽  
Shi Xiong Wu
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Step Length ◽  
Mathematical Relationship ◽  
Cutting Depth ◽  
Machining Time ◽  
High Speed Milling ◽  
Tool Paths ◽  
Machining Quality ◽  
Radial Depth

In order to decrease the radial amout of cutting depth in high speed milling,optimized arc transition has been proposed in corner milling and the circular trochoid model has been used to remove the residual. Mathematical relationship based on radial depth of cutting constrain among tool radius, trochoid radius and tool step length in circular trochoid model have been analyzed .Based on the goal to limiting the radial cutting depth, appropriate parameters have been computed for higher machining quality. To verify the effectiveness of the proposed method, a compared test has been conducted. Experiment shows that optimized tool paths cause a slight increase in machining time but obtain weaker processing vibration and superior machining precision.

Effect of Tool Path Strategies in Pocket Milling of Aluminium Epoxy

2014 ◽  
Vol 903 ◽  
pp. 15-20 ◽  
Author(s):  
Rusdi Mat Song ◽  
Safian Sharif ◽  
Ahmad Yasir Md Said ◽  
Mohd Tanwyn Mohd Khushairi
Keyword(s):  
Computer Aided Design ◽  
High Speed ◽  
Tool Path ◽  
High Speed Steel ◽  
Cutting Parameters ◽  
Cnc Machining ◽  
Numerical Control ◽  
Machining Time ◽  
Pocket Milling ◽  
Cad Cam

Selection of the most suitable tool path strategy is very essential during machining especially in computer aided design and manufacture (CAD/CAM) as well as computer numerical control (CNC) machining. Existence of various tool path strategies to be applied on advanced composite materials such as aluminium epoxy required extensive researches in determining the best combination of tool path and cutting parameters for better machinability performance. Pocket milling of aluminium epoxy specimen via CAD/CAM was conducted in this study to investigate the effect of three types of tool path strategies namely Inward Helical, Outward Helical and Back and Forth. Uncoated high speed steel (HSS-Co8) ball end mill was used throughout the experiments. The machining responses that were evaluated include machining time, tool wear rate, tool life and surface finish of the machined pockets. In general, the effect of tool path strategy was highly significant on the machining responses and results showed that Back and Forth strategy offered the best machinability results when compared to the other strategies.

scholarly journals 5-Axis Flank Milling Tool Path Smoothing Based on Kinematical Behaviour Analysis

2011 ◽  
Vol 223 ◽  
pp. 691-700 ◽  
Author(s):  
Xavier Beudaert ◽  
Pierre Yves Pechard ◽  
Christophe Tournier
Keyword(s):  
Tool Path ◽  
Maximum Velocity ◽  
Flank Milling ◽  
Machining Time ◽  
Machined Surface ◽  
Tool Paths ◽  
Area Of Interest ◽  
Milling Tool ◽  
Joint Coordinates ◽  
Kinematical Behaviour

In the context of 5-axis flank milling, the machining of non-developable ruled surfaces may lead to complex tool paths to minimize undercut and overcut. The curvature characteristics of these tool paths generate slowdowns affecting the machining time and the quality of the machined surface. The tool path has to be as smooth as possible while respecting the maximum allowed tolerance. In this paper, an iterative approach is proposed to smooth an initial tool path. An indicator of the maximum feedrate is computed using the kinematical constraints of the considered machine tool, especially the maximum velocity, acceleration and jerk. Then, joint coordinates of the tool path are locally smoothed in order to raise the effective feedrate in the area of interest. Machining simulation based on a N-buffer algorithm is used to control undercut and overcut. This method has been tested in flank milling of an impeller and can be applied in 3 to 5-axis machining.

Use of a virtual milling system to generate power-aware tool paths for 2.5-dimensional pocket machining

2019 ◽  
Vol 233 (13) ◽  
pp. 2419-2435 ◽  
Author(s):  
David Manuel Ochoa González ◽  
Joao Carlos Espindola Ferreira
Keyword(s):  
Power Consumption ◽  
Tool Path ◽  
Tool Path Generation ◽  
Path Generation ◽  
Machining Time ◽  
Power Requirement ◽  
Pocket Machining ◽  
Direction Parallel ◽  
Generation Algorithm ◽  
Tool Paths

Traditional (direction-parallel and contour-parallel) and non-traditional (trochoidal) tool paths are generated by specialized geometric algorithms based on the pocket shape and various parameters. However, the tool paths generated with those methods do not usually consider the required machining power. In this work, a method for generating power-aware tool paths is presented, which uses the power consumption estimation for the calculation of the tool path. A virtual milling system was developed to integrate with the tool path generation algorithm in order to obtain tool paths with precise power requirement control. The virtual milling system and the tests used to calibrate it are described within this article, as well as the proposed tool path generation algorithm. Results from machining a test pocket are presented, including the real and the estimated power requirements. Those results were compared with a contour-parallel tool path strategy, which has a shorter machining time but has higher in-process power consumption.

Region based Efficient CNC Machining using Point Cloud Data

2020 ◽  
pp. 1-35
Author(s):  
Mandeep Dhanda ◽  
Aman Kukreja ◽  
Sanjay Pande
Keyword(s):  
Path Planning ◽  
Surface Quality ◽  
Point Cloud ◽  
Tool Path ◽  
Cnc Machining ◽  
Real Surface ◽  
Tool Path Planning ◽  
Machining Time ◽  
Cloud Data ◽  
Planning Strategy

Abstract This paper presents an efficient tool path planning strategy for three-axis CNC machining using curvature based segmentation (CBS) of freeform surface from its representation in the form of a point cloud. Curvature parameters estimated over the point data are used to partition the surface into convex, concave, and saddle like regions. Grid based adaptive planar tool path planning strategy is developed to machine each region separately within its boundaries. In addition to the region by region machining, strategy to stitch the obtained regions is also developed to minimize the tool lifts and tool marks. The developed region based tool path planning strategy is compared with the point cloud based adaptive planar strategy, iso-scallop strategy and commercial software for parts with various complexities. The result shows significant improvement in terms of performance parameters viz. machining time, tool path length and code length while maintaining the desired part surface quality. The proposed method is also tested by machining a real surface and analyzing its surface quality.

Adaptive Tool Path Planning Strategy for 5-Axis CNC Machining of Free Form Surfaces

2019 ◽  
Author(s):  
Hrishikesh Mane ◽  
S. S. Pande
Keyword(s):  
Tool Path ◽  
Cnc Machining ◽  
Memory Storage ◽  
Free Form ◽  
Cnc Machine ◽  
Planning Strategy ◽  
Part Quality ◽  
Tool Paths ◽  
Path Topology ◽  
Free Form Surfaces

Abstract This paper presents a curvature based adaptive iso-parametric strategy for the efficient machining of free form surfaces on 5-axis CNC machine using the flat end mill tool. One iso-parametric boundary of the surface is selected as the initial tool path. Set of cutter contact (CC) points are chosen adaptively on the initial tool path considering desired profile tolerance. Adjacent iso-parametric tool paths are computed adaptively based on the scallop height constraint unlike the traditional iso-parametric approach. The path topology is post-processed to generate the part program for 5-axis CNC machine in ISO format. The system was rigorously tested for various case studies by comparing the results with the traditional 5-axis iso-parametric tool path strategy, iso-scallop strategy and iso-planar strategy of a commercial software. Our system was found to generate efficient tool paths in terms of part quality, productivity and memory storage compared to the conventional strategies.

A New Method for the Generation of Tool Paths for Finishing Near Net Shape Components

2013 ◽  
Author(s):  
Edgar A. Mendoza López ◽  
Hugo I. Medellín Castillo ◽  
Dirk F. de Lange ◽  
Theo Lim
Keyword(s):  
Geometric Modeling ◽  
Tool Path ◽  
Cutting Tools ◽  
Approximation Error ◽  
Cnc Machining ◽  
New Method ◽  
End Mill ◽  
Tool Paths ◽  
Near Net Shape ◽  
Finish Cut

The CNC machining has been one of the most recurrent processes used for finishing NNS components. This paper presents a new method for the generation of tool paths for machining 3D NNS models. The proposed approach comprises two machining stages: rough cut and finish cut, and three types of cutting tools: ball-end mill, flat-end mill and fillet-end mill. The proposed tool path generation algorithm is based on: (1) approximation of the model surfaces by points using slice planes and visibility analysis, (2) accessibility analysis of the tool, (3) approximation error and tolerance evaluation, (4) collision analysis of tool and tool holder. The tools paths generated are exported as a CNC program. The implementation was carried out in C++ using the ACIS® geometric modeling kernel to support the required geometric operations. To prove the effectiveness of the system several models with variable geometric complexity were tested. The results have shown that the proposed system is effective and therefore can be used to generate the tool paths required for finishing 3D NNS components.

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