Length-Optimal Tool Path Planning for Freeform Surfaces with Preferred Feed Directions Based on Poisson Formulation

2021 ◽  
pp. 103072
Author(s):  
Qiang Zou
Author(s):  
Mandeep Dhanda ◽  
S. S. Pande

This paper reports the development of an efficient tool path planning strategy for CNC machining of freeform surfaces directly from their representation in the form of point cloud. A grid based adaptive isoplanar tool path planning system has been designed and implemented for 3axis CNC machine using ball end mill. Inverse tool offset algorithm (IOM) is used to compute initial uniform CL (Cutter Location) grid points. From these CL points, surface slope and curvature are estimated and the forward and side step errors likely to be produced during machining are computed. The grid is subsequently refined through segmentation if the error values exceed the user defined tolerances. Adaptive grid refinement is continued iteratively till the error values converge below the prescribed tolerance limits. The grid (CL) points are sequenced to generate the final tool path. The software system developed takes the input part model as point cloud and generates post-processed CNC part program in the ISO format. The CNC part programs were extensively tested for various case studies on the commercial CNC simulator as well on the actual CNC machine. The results were compared with those from the commercial software for the same process conditions. Our system was found to generate more efficient tool paths in terms of enhanced productivity, part quality and reduced memory requirement.


2008 ◽  
Vol 392-394 ◽  
pp. 575-579
Author(s):  
Yu Hao Li ◽  
Jing Chun Feng ◽  
Y. Li ◽  
Yu Han Wang

Self-affine and stochastic affine transforms of R2 Iterated Function System (IFS) are investigated in this paper for manufacturing non-continuous objects in nature that exhibit fractal nature. A method for modeling and fabricating fractal bio-shapes using machining is presented. Tool path planning algorithm for numerical control machining is presented for the geometries generated by our fractal generation function. The tool path planning algorithm is implemented on a CNC machine, through executing limited number of iteration. This paper describes part of our ongoing research that attempts to break through the limitation of current CAD/CAM and CNC systems that are oriented to Euclidean geometry objects.


Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 237
Author(s):  
Yue Liu ◽  
Zhanqiang Liu ◽  
Wentong Cai ◽  
Yukui Cai ◽  
Bing Wang ◽  
...  

Aero-engine blades are manufactured by electroforming process with electrodes. The blade electrode is usually machined with five-axis micromilling to get required profile roughness. Tool path planning parameters, such as cutting step and tool tilt angle, have a significant effect on the profile roughness of the micro-fillet of blade electrode. In this paper, the scallop height model of blade electrode micro-fillet processed by ball-end milling cutter was proposed. Effects of cutting step and tool tilt angle the machined micro-fillet profile roughness were predicted with the proposed scallop height model. The cutting step and tool tilt angle were then optimised to ensure the contour precision of the micro-fillet shape requirement. Finally, the tool path planning was generated and the machining strategy was validated through milling experiments. It was also found that the profile roughness was deteriorated due to size effect when the cutting step decreased to a certain value.


2021 ◽  
Author(s):  
J.Y. Feng ◽  
Z.C. Wei ◽  
M.J. Wang ◽  
X.Q. Wang ◽  
M.L. Guo

Abstract U-pass milling is a roughing method that combines the characteristics of flank milling with conventional trochoidal milling. The tool cuts in and out steadily, and the tool–workpiece wrap angle is maintained within a small range. This method can smooth the cutting force and reduce the peak cutting force while avoiding cutting heat accumulation, which can significantly improve the processing efficiency and reduce tool wear. In this study, a tool path model is established for U-pass milling, and the characteristic parameters of the path are defined. Through a comparative test of three-axis groove milling, it is demonstrated that the peak value and average value of the cutting force are reduced by 25% and 60%, respectively. An impeller runner is considered as the processing object, and the milling boundary parameters are pretreated. A tiling micro-arc mapping algorithm is proposed, which maps the three-dimensional boundary to the two-dimensional parameter domain plane with the arc length as the coordinate axis, and the dimensionally reduced tool contact point distribution form is obtained. The geometric domain tool position point and the interference-free tool axis vector are obtained by calculating the bidirectional proportional domain of the runner and the inverse mapping of any vector in the parameter domain. Finally, the calculation results are nested into the automatically programmed tool (APT) encoding form, and the feasibility of the five-axis U-pass milling tool path planning method is verified through a numerical example.


Author(s):  
Jingyang Feng ◽  
Zhaocheng Wei ◽  
Minjie Wang ◽  
Xueqin Wang ◽  
Minglong Guo

Author(s):  
Sumedh Ghogare ◽  
S. S. Pande

This paper reports the development of an efficient iso-scallop tool path planning strategy for machining of freeform surfaces on a three axis CNC milling center using the point cloud as the input. Boundary of the point cloud is chosen as the Master Cutter Path, using which the scallop points are computed. Adjacent side tool paths are computed using these scallop points and the path planning process is completed till the entire surface is covered. The system generates post-processed NC program in ISO format which was extensively tested for various case studies. The results were compared with the iso-planar tool path strategy from commercial software. Our system was found to generate efficient tool path in terms of part quality, productivity and storage memory.


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