scholarly journals Creating a Multi-axis Machining Postprocessor

10.14311/1614 ◽  
2012 ◽  
Vol 52 (4) ◽  
Author(s):  
Petr Vavruška

This paper focuses on the postprocessor creation process. When using standard commercially available postprocessors it is often very difficult to modify its internal source code, and it is a very complex process, in many cases even impossible, to implement the newly-developed functions. It is therefore very important to have a method for creating a postprocessor for any CAM system, which allows CL data (Cutter Location data) to be generated to a separate text file. The goal of our work is to verify the proposed method for creating a postprocessor. Postprocessor functions for multi-axis machiningare dealt with in this work. A file with CL data must be translated by the postprocessor into an NC program that has been customized for a specific production machine and its control system. The postprocessor is therefore verified by applications for machining free-form surfaces of complex parts, and by executing the NC programs that are generated on real machine tools. This is also presented here.

Author(s):  
Yuki Takanashi ◽  
Hideki Aoyama

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.


2012 ◽  
Vol 622-623 ◽  
pp. 525-530
Author(s):  
Tran Duc Tang

This paper presents a postprocessor for five-axis milling machine that capable of converting CL (cutter location) data to machine control data (NC program). The proposed postprocessor method is based on inverse kinematics transformation and postprocessor module is programmed in Visual Basic language. The Deckel Maho DMU 50 eVoluion five-axis machine with two rotary axes (B and C) on the table is modeled and verified in software VERICUT® to validate the NC data generated by proposed postprocessor.


1994 ◽  
Vol 116 (2) ◽  
pp. 253-259 ◽  
Author(s):  
K. Suresh ◽  
D. C. H. Yang

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.


2013 ◽  
Vol 284-287 ◽  
pp. 493-497
Author(s):  
Chen Hua She ◽  
Wen Yuh Jywe ◽  
Jheng Jie Huang

Five-axis machine tools with three linear axes and two rotary axes can produce complex products with free-form surfaces requiring a high degree of precision. However, motion errors of each axis and its assembly error are accumulated in the positioning error of the cutting tool relative to a workpiece. There are many devices reported in the literature on the identification of kinematic errors based on the measurement of the motion error. According to the measurement paths in the ISO draft, ISO/CD 10791-6, the kinematic tests can be applicable to different configurations of five-axis machine tools. However, the advanced controller with tool center point (TCP) function is required while performing kinematic tests. This paper proposed the methodology of generating measurement path without TCP function for B-type five-axis machine tool. The developed module can transform the measuring path into an NC program used for lower hand controller. Verification using VERICUT solid cutting simulation software demonstrated the veracity of the generated five-axis NC code. The proposed methodology is applicable in a wide range of five-axis machine tool configurations; however, further testing with actual measuring applications will be required for further verification.


2021 ◽  
Vol 15 (4) ◽  
pp. 521-528
Author(s):  
Yuki Takanashi ◽  
Hideki Aoyama ◽  
Song Cheol Won ◽  
◽  

In general, NC programs for machining free-form surfaces using a computer numerical control (CNC) machine tool are generated using a computer-aided manufacturing (CAM) system. The tool paths (CL data) generated by a CAM system are approximated straight-line segments based on tolerance (allowable error). As a result, the tolerance affects the machining accuracy and time. If the tolerance is set to a small value, the lengths of the segments are shortened, and the machining accuracy is improved. The process in which a CNC machine tool reads and analyzes an NC program and controls the motors requires a minimum processing time of an NC program block (block-processing time). Therefore, if the lengths of the approximated straight-line segments are too small, it will be impossible to reach the indicated feed speed, and the machining time will be longer. In this study, by identifying the block-processing time of a CNC controller and deriving the appropriate length of the approximated straight-line segment based on the block-processing time, a CL data creation method that is capable of high-speed and high-accuracy free-form surface machining is proposed. In addition, experimental verification tests of the method are conducted.


Author(s):  
Cheng-Ming Chuang ◽  
Chun-Yan Chen ◽  
Hong-Tzong Yau

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.


2013 ◽  
Vol 404 ◽  
pp. 694-698
Author(s):  
Feng Yun Lin

Polishing, a kind of finishing process done after machining is necessary to obtain a good surface roughness as well as the form accuracy. In this paper, instead of manual polishing work, a robotic polishing system is introduced. A trajectory generator needed for generating the robot polishing path are taken from the cutter location data generated from the postprocessor of a CAD system. Using the trajectory generator, the present polishing robot doesnt need the conventional complicated teaching process. Position interpolation algorithm between two CL data is proposed, and the robot control commands can also be generated using an industrial robot Motoman sv3.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Mehwish Bari ◽  
Ghulam Mustafa ◽  
Abdul Ghaffar ◽  
Kottakkaran Sooppy Nisar ◽  
Dumitru Baleanu

AbstractSubdivision schemes (SSs) have been the heart of computer-aided geometric design almost from its origin, and several unifications of SSs have been established. SSs are commonly used in computer graphics, and several ways were discovered to connect smooth curves/surfaces generated by SSs to applied geometry. To construct the link between nonstationary SSs and applied geometry, in this paper, we unify the interpolating nonstationary subdivision scheme (INSS) with a tension control parameter, which is considered as a generalization of 4-point binary nonstationary SSs. The proposed scheme produces a limit surface having $C^{1}$ C 1 smoothness. It generates circular images, spirals, or parts of conics, which are important requirements for practical applications in computer graphics and geometric modeling. We also establish the rules for arbitrary topology for extraordinary vertices (valence ≥3). The well-known subdivision Kobbelt scheme (Kobbelt in Comput. Graph. Forum 15(3):409–420, 1996) is a particular case. We can visualize the performance of the unified scheme by taking different values of the tension parameter. It provides an exact reproduction of parametric surfaces and is used in the processing of free-form surfaces in engineering.


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