Using the direct cutting paths approach on aluminum alloy cone frustum part for evaluating a five-axis machine tool with Taguchi method

Author(s):  
Han-Jui Chang ◽  
Shang-Liang Chen ◽  
Po-Yi Lee

It is difficult to compare five-axis machine tools complex analysis against independent motion of multi-type machines; more specifically, there has been no breakthrough involving the interaction effect factors from cutting analysis. Therefore, the defining and quantifying of data are important in assessing the overall performance of five-axis machine tools, and allow for the evaluation of each subsequent interaction motion analysis. Among various cutting test models, the machining of a cone frustum as specified in National Aerospace Standard 979 and International Standard Organization 10791-7 is widely accepted as a performance test standard for five-axis machining centers. Although it gives a demonstration of the machine’s machining performance, it is generally difficult to identify the overall effects of kinematic interaction within the profile of the finished workpiece. This is new approach to a previously defined 10 direct cutting paths method to evaluate the performance of each cone frustum motion, and it is not limited to only evaluating single direction or displacement on a five-axis machine tool. Among the 10 cutting paths, four of them are real five-axis cutting and the remaining paths are non-real five-axis cutting. This allowed the test of four to five mixed external forces at the same time, which the instrument is not able to measure. This article further proposes to calculate the factorial effect of interaction, based on the Taguchi method signal-to-noise ratio, mechanical advantage, and Variables separable model, which allows for the comparison of the performance of different five-axis machine tool types.

2013 ◽  
Vol 284-287 ◽  
pp. 638-644 ◽  
Author(s):  
Shang Liang Chen ◽  
Han Jui Chang ◽  
Jeng Nan Lee ◽  
Shu Ting Chen

The current evaluation of machine tools’ machining performance relies on instruments measurement but not actual/real machining method. However, using instruments measurement evaluation is not only costly but also due to the installation defect of instruments, resulted in performance examination errors. This paper proposed to use titled condition of 10-15 degrees on the base of part’s clamp with VERICUT software to perform simulation for achieving the purpose of examine tools’ machining performance. Findings showed that under the tilted condition of 10-15 degree, turn-mill type of interruptions occurred and unable to proceed. Modification on the cone frustum and anti-cone frustum design was applied to overcome turn-mill interruptions issues. This simulation results showed achievement of turn-mill type tools’ machining performance evaluation with anti-cone frustum design.


Author(s):  
Zhong Jiang ◽  
Jiexiong Ding ◽  
Qicheng Ding ◽  
Li Du ◽  
Wei Wang

Nowadays the five-axis machine tool is one of the most important foundations of manufacturing industry. To guarantee the accuracy of the complex surface machining, multi-axis linkage performance detection and compensation of five-axis machine tools is necessary. RTCP (Rotation Tool Center Point) is one of the basic essential functions for the five-axis machine tools, which can keep the tool center with the machining trajectory when five axes move synchronously. On the basis of RTCP function, a way to detect multi-axes linkage performance of five-axis machine tools is briefly introduced, and linkage error model is built in accordance with the topological structure of machine tool. Based on the feature of the linkage errors of the five-axis machine tool, the error tracing and compensation method is proposed. Some simulations and experiments that verify the error tracing method could locate the linkage error category are established. Therefore, a new attempt to detect and compensate the linkage error of the five-axis machine tool is provided in this paper.


Author(s):  
Jennifer Creamer ◽  
Patrick M. Sammons ◽  
Douglas A. Bristow ◽  
Robert G. Landers ◽  
Philip L. Freeman ◽  
...  

This paper presents a geometric error compensation method for large five-axis machine tools. Compared to smaller machine tools, the longer axis travels and bigger structures of a large machine tool make them more susceptible to complicated, position-dependent geometric errors. The compensation method presented in this paper uses tool tip measurements recorded throughout the axis space to construct an explicit model of a machine tool's geometric errors from which a corresponding set of compensation tables are constructed. The measurements are taken using a laser tracker, permitting rapid error data gathering at most locations in the axis space. Two position-dependent geometric error models are considered in this paper. The first model utilizes a six degree-of-freedom kinematic error description at each axis. The second model is motivated by the structure of table compensation solutions and describes geometric errors as small perturbations to the axis commands. The parameters of both models are identified from the measurement data using a maximum likelihood estimator. Compensation tables are generated by projecting the error model onto the compensation space created by the compensation tables available in the machine tool controller. The first model provides a more intuitive accounting of simple geometric errors than the second; however, it also increases the complexity of projecting the errors onto compensation tables. Experimental results on a commercial five-axis machine tool are presented and analyzed. Despite significant differences in the machine tool error descriptions, both methods produce similar results, within the repeatability of the machine tool. Reasons for this result are discussed. Analysis of the models and compensation tables reveals significant complicated, and unexpected kinematic behavior in the experimental machine tool. A particular strength of the proposed methodology is the simultaneous generation of a complete set of compensation tables that accurately captures complicated kinematic errors independent of whether they arise from expected and unexpected sources.


Author(s):  
Peng Xu ◽  
Benny C. F. Cheung ◽  
Bing Li

Calibration is an important way to improve and guarantee the accuracy of machine tools. This paper presents a systematic approach for position independent geometric errors (PIGEs) calibration of five-axis machine tools based on the product of exponentials (POE) formula. Instead of using 4 × 4 homogeneous transformation matrices (HTMs), it establishes the error model by transforming the 6 × 1 error vectors of rigid bodies between different frames resorting to 6 × 6 adjoint transformation matrices. A stable and efficient error model for the iterative identification of PIGEs should satisfy the requirements of completeness, continuity, and minimality. Since the POE-based error models for five-axis machine tools calibration are naturally complete and continuous, the key issue is to ensure the minimality by eliminating the redundant parameters. Three kinds of redundant parameters, which are caused by joint symmetry information, tool-workpiece metrology, and incomplete measuring data, are illustrated and explained in a geometrically intuitive way. Hence, a straightforward process is presented to select the complete and minimal set of PIGEs for five-axis machine tools. Based on the established unified and compact error Jacobian matrices, observability analyses which quantitatively describe the identification efficiency are conducted and compared for different kinds of tool tip deviations obtained from several commonly used measuring devices, including the laser tracker, R-test, and double ball-bar. Simulations are conducted on a five-axis machine tool to illustrate the application of the calibration model. The effectiveness of the model is also verified by experiments on a five-axis machine tool by using a double ball-bar.


2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Song Gao ◽  
Jihong Chen ◽  
Shusheng Liu ◽  
Xiukun Yuan ◽  
Pengcheng Hu ◽  
...  

Abstract Due to their superior machining quality, efficiency, and availability, five-axis machine tools are important for the manufacturing of complicated parts of freeform surfaces. In this study, a new type of the five-axis machine tool was designed that is composed of four rotary axes as well as one translational axis. Given the structure of the proposed machine tool, an inverse kinematics analysis was conducted analytically, and a set of methods was then proposed to address the issues in the kinematic analysis, e.g., the singularity and multi-solution problems. Compared with traditional five-axis machine tools, which are typically composed of three linear axes and two rotary axes, the proposed machine tool exhibited better kinematic performance with machining parts with hub features, such as impellers, which was validated by simulations and real cuttings.


2014 ◽  
Vol 701-702 ◽  
pp. 874-878
Author(s):  
Shao Hsien Chen ◽  
Chin Mou Hsu ◽  
Kuo Lin Chiu ◽  
Chu Peng Chan

Swivel spindle head is a key component used in five-axis machine tool of high performance and is of great importance in application and design. Nowadays, more and more components are manufactured by high performance multi-axis CNC machine tools, such as components of spaceflight, renewable energy and automobile, etc. Therefore, high performance machine tools of multiple axes are more and more urgently demanded, while Swivel spindle head is one of the most important components for a multi-axis machine tool. Hence, Swivel spindle head is one of the key to developers multi-axis machine tool . The study explores the highly responsive direct-driving motor able to drive the spindle head to rotate with multi-driving rotary technology. The dual-driving motor rotates via multi-driving units, generates torsion that magnifies and eliminates its clearance, and then drives the spindle head to rotate. Results of the test show that the completed machine tool can meet the standards of dual axis rotary head with high preformation in, no matter, speed, distance, positional accuracy, repeated accuracy or maximum torque, etc.


2012 ◽  
Vol 8 (1) ◽  
pp. 158-163 ◽  
Author(s):  
Shang Liang Chen ◽  
Tung Hsien Hsieh ◽  
Wen Yuh Jywe ◽  
Chen-Hua She ◽  
Jeng-Nan Lee

Author(s):  
C-W Lin

As spindle speeds increase, the variations caused by high-speed effects become more significant. Therefore, in the initial design stage, it is necessary for machine tool design engineers to construct a robust high-speed machine tool that possesses high first-mode natural frequencies (FMNFs) and is insensitive to high operating speeds. In this article, Taguchi method is used to identify the optimal values of design variables (DVs) for a robust high-speed spindle system with respect to the signal-to-noise ratio (SNR) of system FMNF. The L18 orthogonal array covers seven main DVs at three levels each, one main DV at two levels, and the noise factor spindle speeds at six levels. The results show that the new optimal design has improved the SNR of the FMNF by 2.06 dB from the original design; this implies that the quality loss has been reduced to 62 per cent of its original value. The optimal design has been verified by a confirmation numerical experiment.


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