Error Analysis by Square 3 x 3 Machining Method for Five-Axis Machining Centers

2020 ◽  
Author(s):  
Shigehiko Sakamoto ◽  
Atsushi Yokoyama ◽  
Kazumasa Nakayasu ◽  
Toshihiro Suzuki ◽  
Shinji Koike
Keyword(s):  
International Standards ◽  
Test Method ◽  
Accuracy Evaluation ◽  
Alignment Error ◽  
Machined Surface ◽  
Machining Center ◽  
Alignment Errors ◽  
Assembly Error ◽  
Five Axis ◽  
Machined Surfaces

Abstract The establishment of international standards for 5-axis control machining centers has been supported by the high interest of each country. Internationally, various accuracy inspection methods have been proposed and widely discussed. Accuracy measuring devices for these purposes have also been proposed. In 2014, inspection methods for 5-axis machines were published in ISO 10791-6 and 10791-7. In this research, we propose a test method to process 9 square faces as a new accuracy evaluation method. We simulate the influence of assembly error by the proposed square 3 × 3 machining method on the machined surface. By processing 9 square faces with different tool angle on the same plane, it was possible to evaluate the influence of assembly errors in the 5-axis machining center on the machined surface. Nine surfaces machined by the square 3 × 3 processing method cause differences in surface height due to alignment errors. In addition, nine machined surfaces become all diagonal not parallelism. The alignment errors of the 5-axis machining center is identified by evaluating the orientation of the machined surfaces. Specifically, we propose a newly method to measure the height difference of nine surfaces. Then, the possibility of identifying the alignment error of the 5-axis machining center using the measurement results is shown.

Sensitivity Analysis of Error Motions and Geometric Errors in the Case of Sphere-Shaped Workpiece

2020 ◽  
Author(s):  
Zongze Li ◽  
Ryuta Sato ◽  
Keiichi Shirase
Keyword(s):  
Sensitivity Analysis ◽  
Machine Tools ◽  
End Milling ◽  
Geometric Errors ◽  
Machined Surface ◽  
Error Sources ◽  
Motion Error ◽  
Machining Center ◽  
Machining Errors ◽  
Five Axis

Abstract Motion error of machine tool feed axes influences the machined workpiece accuracy. However, the influences of each error sources are not identical; some errors do not influence the machined surface although some error have significant influences. In addition, five-axis machine tools have more error source than conventional three-axis machine tools, and it is very tough to predict the geometric errors of the machined surface. This study proposes a method to analyze the relationships between the each error sources and the error of the machined surface. In this study, a kind of sphere-shaped workpiece is taken as a sample to explain how the sensitivity analysis makes sense in ball-end milling. The results show that the method can be applied for the axial errors, such as motion reversal errors, to make it clearer to obverse the extent of each errors. In addition, the results also show that the presented sensitivity analysis is useful to investigate that how the geometric errors influence the sphere surface accuracy. It can be proved that the presented method can help the five-axis machining center users to predict the machining errors on the designed surface of each axes error motions.

Sensitivity Analysis Between Error Motions and Machined Shape Errors in Five-Axis Machining Centers: In Case of S-Shaped Machining Test by a Square End Mill

2019 ◽  
Author(s):  
Zongze Li ◽  
Ryuta Sato ◽  
Keiichi Shirase ◽  
Yukitoshi Ihara
Keyword(s):  
Sensitivity Analysis ◽  
Coordinate System ◽  
Complex Surface ◽  
Machining Accuracy ◽  
Machined Surface ◽  
Machining Center ◽  
Shape Errors ◽  
Machining Test ◽  
Tool Motion ◽  
Five Axis

Abstract Five-axis machining center, combined three linear and two rotary axes, has been increasingly used in complex surface machining. However, as the two additional axes, the machined surface under table coordinate system is usually different from the tool motion under machine coordinate system, and as a result, it is very tough to predict the machined shape errors caused by each axes error motions. This research presents a new kind of sensitivity analysis method, to find the relationship between error motions of each axis and geometric errors of machined shape directly. In this research, the S-shaped machining test is taken as a sample to explain how the sensitivity analysis makes sense. The results show that the presented sensitivity analysis can investigate how the error motions affect the S-shaped machining accuracy and predicted the influence of error motions on certain positions, such as the reversal errors of the axes around motion reversal points. It can be proved that the presented method can help the five-axis machining center users to predict the machining errors on the designed surface of each axes error motions.

Proposal of a Machining Test of Five-Axis Machining Centers Using a Truncated Square Pyramid

2012 ◽  
Vol 523-524 ◽  
pp. 475-480 ◽  
Author(s):  
Katsunori Ohta ◽  
Zhi Meng Li ◽  
Masaomi Tsutsumi
Keyword(s):  
Linear Interpolation ◽  
Test Method ◽  
Rotary Table ◽  
Evaluation Standard ◽  
Machining Center ◽  
Geometric Deviations ◽  
Machining Test ◽  
Simulation And Experiment ◽  
Universal Spindle ◽  
Five Axis

NAS 979 has been used for over 40 years as a performance evaluation standard for five-axis machining centers. This standard provides some finishing conditions of the cone-frustum under five-axis control, and prescribes the measuring methods and permissible tolerances of geometric deviations. However, this standard cannot be applied to the tilting rotary table type five-axis machining center but to the universal spindle head type one. When the standard is applied to the tilting rotary table type, it is not clear yet that the effects of the geometric and synchronous deviations which influence the measured results. Thus, there are no methods for evaluating the accuracy of linear interpolation movement under simultaneous five-axis control. This paper proposes a machining test method using a truncated square pyramid for checking the accuracy of the tilting rotary table type five-axis machining centers. In the simulation and experiment, the bottom of the truncated square pyramid with a half apex angle of 15° is mounted on a fixture with a slope of 10° or 20°, and feed velocity of each axis is analyzed by changing the center position.

Reliability Test Design for Five-Axis Machining Center

2010 ◽  
Vol 44-47 ◽  
pp. 834-838
Author(s):  
Xiang Po Zhang ◽  
Nai Hui Yu ◽  
Jian Zhong Shang ◽  
Zhuo Wang
Keyword(s):  
Test Method ◽  
Test Design ◽  
Reliability Test ◽  
Reliability Design ◽  
Reliability Level ◽  
Test Criterion ◽  
Machining Center ◽  
Five Axis

Reliability test is the most effective way to achieve the data needed in machining center’s reliability design and assessment, and also a compulsory technological way to improve the reliability of the machining center. For the purposes of evaluating and improving the reliability level of machining center effectively, a laboratory reliability test for five-axis machining center was designed. This test method designed in this paper has the characteristics of high pertinence and easily realized in engineering, and it can be generalized as a reliability test criterion for five-axis machining center.

A Geometrical Simulation System of Ball End Finish Milling Process and Its Application for the Prediction of Surface Micro Features

2005 ◽  
Vol 128 (1) ◽  
pp. 74-85 ◽  
Author(s):  
Xianbing Liu ◽  
Masakazu Soshi ◽  
Abhijit Sahasrabudhe ◽  
Kazuo Yamazaki ◽  
Masahiko Mori
Keyword(s):  
Cutting Tool ◽  
Milling Process ◽  
Simulation System ◽  
Machining Parameters ◽  
Machined Surface ◽  
Fundamental Study ◽  
Surface Features ◽  
The Difference ◽  
Five Axis ◽  
Machined Surfaces

Finish milling with a ball end mill is a key process in manufacturing high-precision and complex workpieces, such as dies and molds. Because of the complexity of the milling process, it is difficult to evaluate the microcharacteristics of machined surfaces real time, which necessitates the simulation of the process. In this area, the existing related simulation researches mainly focus on scallop height evaluation, but few have presented a whole picture of the microcharacteristics of milled surfaces. This paper develops a comprehensive simulation system based on a Z-map model for predicting surface topographic features and roughness formed in the finish milling process and studies the effect of machining parameters. The adoption of the discretization concept of the tool’s cutting motion makes it possible to dynamically track the cutting tool-workpiece interaction with the tool movement and to describe the cutting edges-workpiece discrete cutting interaction more realistically and, therefore, the microcharacteristics of the machined surfaces more accurately. Also, the effects of the cutting tool run-out and wear are incorporated into the developed model through modifying the tool center motion and the cutting-edge shape, respectively. As a fundamental study, the tool-swept envelope has been simulated. The developed simulation system is applied to thoroughly study the surface features formed by the 2.5-axis finish milling process. The application for general three-axis machining is discussed. Additionally, this paper studies the effect of the tool inclination, which is the most common characteristic in 3+2- or five-axis milling processes, on the machined surface features. Experiments are carried out to study the milling process and to verify the simulation results. The difference between the simulated and experimental results is discussed, and the reason behind the difference is explored.

scholarly journals Study on cutting trace shape control of machined surface by radius end mill with five-axis controlled machining center

2018 ◽  
Vol 84 (860) ◽  
pp. 17-00508-17-00508
Author(s):  
Toshiki HIROGAKI ◽  
Eiichi AOYAMA ◽  
Seigo NAKAMURA ◽  
Masahiro UENOYAMA
Keyword(s):  
Shape Control ◽  
End Mill ◽  
Machined Surface ◽  
Machining Center ◽  
Five Axis

Improved Accuracy of a Machining Tool With a Constant Cutting Speed Vector and Outside Approach Path

2020 ◽  
Author(s):  
Takamaru Suzuki ◽  
Shoya Iwama ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Takakazu Ikegami ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Cutting Speed ◽  
Feed Speed ◽  
Actual Process ◽  
Shape Error ◽  
Direct Drive ◽  
Wireless Internet ◽  
Machined Surface ◽  
Machining Center ◽  
Five Axis

Abstract A five-axis machining center is equipped with a direct drive motor on a rotary axis and is capable of synchronous control, which makes it a feasible tool for quickly and accurately machining complicated three-dimensional surfaces such as propellers and hypoid gears. However, the accuracy of the machined shape and consistency of the freeform machined surface both need to be improved. We developed a method for maintaining the feed speed vector at the milling point by controlling three axes of the five-axis machining center (two linear and one rotary) to improve the quality of the machined surface considering differences in the servo characteristics of the three axes during the actual process. Experimental results showed that using the proposed method with an outside approach path for the machining tool greatly reduced the shape error. The effectiveness of the proposed method was verified by using a wireless Internet of Things holder to monitor the machining force.

Gloss Estimating Method of Finished Surface Machined by Ball Nose End-Milling under Constant Contact Angle with a Five-Axis Controlled Machining Center

2012 ◽  
Vol 516 ◽  
pp. 475-480
Author(s):  
Kenichi Terada ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Keiji Ogawa
Keyword(s):  
Feed Rate ◽  
End Milling ◽  
Work Piece ◽  
Machined Surface ◽  
Ball End Milling ◽  
Machining Center ◽  
Reflected Light ◽  
Finished Surface ◽  
Constant Contact Angle ◽  
Five Axis

In recent years, studies have been conducted about creating metal moulds using a five-axis controlled machining centre with ball end milling. Most of these reports concern the programming of CAM based on geometry. However, there have been few reports related to polish-less finished surface. Furthermore, a specular surface like a mirror and finishing under a constant angle between ball end milling and the work piece have not been investigated. Therefore, this paper deals with the gloss of the machined surface when feed rate and pick-feed rate are changed to maintain constant surface roughness considering tool run-out under the condition that the angle between the tool and work piece in contact are inclined at 15. However, by changing the combination of feed rate and pick-feed rate, various specular changes and direction of disposition of reflected light were obtained. Therefore, we suggest a new method of evaluating the gloss of these finished surfaces. Comparing results by the proposed method with ones by a glossmeter, it is clear that an appropriate ratio of feed rate and pick-feed rate is important for obtaining finished surface. Moreover, it is demonstrated that the proposed method is effective for estimating the gloss of the machined surface.

scholarly journals The Estimation of Angular Misalignments for Ultra Short Baseline Navigation Systems. Part II: Experimental Results

2013 ◽  
Vol 66 (5) ◽  
pp. 773-787 ◽  
Author(s):  
Hsin-Hung Chen
Keyword(s):  
Trial Data ◽  
Experimental Results ◽  
Experimental Result ◽  
Alignment Error ◽  
Navigation Systems ◽  
Analytical Prediction ◽  
Short Baseline ◽  
Sea Trial ◽  
Alignment Errors ◽  
Cross Track

An algorithm of alignment calibration for Ultra Short Baseline (USBL) navigation systems was presented in the companion work (Part I). In this part (Part II) of the paper, this algorithm is tested on the sea trial data collected from USBL line surveys. In particular, the solutions to two practical problems referred to as heading deviation and cross-track error in the USBL line survey are presented. A field experiment running eight line surveys was conducted to collect USBL positioning data. The numerical results for the sea trial data demonstrated that the proposed algorithm could robustly and effectively estimate the alignment errors. Comparisons of the experimental result with the analytical prediction of roll misalignment estimation in Part I is drawn, showing good agreement. The experimental results also show that an inappropriate estimation of roll alignment error will significantly degrade the quality of estimations of heading and pitch alignment errors.

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