Measurement of Radius of Curvature by Coordinate Measurement Machine

2013 ◽  
Vol 284-287 ◽  
pp. 488-492 ◽  
Author(s):  
Shenq Tsong Chang ◽  
Wei Cheng Lin ◽  
Ting Ming Huang ◽  
Ming Ying Hsu ◽  
Po Hsuan Huang

Radius of curvature is one of the key parameters of optical components. A variety of methods have been developed for this measurement. This paper describes a novel way, named “CMM spherometry by probe compensation”, to measure the radius of curvature of optical surfaces by coordinate measuring machine (CMM). The measurement combines CMM measurement and iteration calculation scheme is presented. The measurement results of CMM and the trace samples are compared. The effect of temperature compensation is discussed.

2015 ◽  
Vol 4 (1) ◽  
pp. 125 ◽  
Author(s):  
Wilma Polini ◽  
Giovanni Moroni

Coordinate Measuring Machine (CMM) inspection planning is an activity performed by well-trained operators, but different measurement techniques, using the same data analysis algorithms yield in different measurement results. This is a well-recognized source of uncertainty in coordinate measurement. A CMM, provided with an automatic inspection planning (CAIP) system, permits to implement more accurate and efficient operating procedures and to fit higher quality assurance standards and tighter production timings.In this paper we present a frame of a CAIP system, able to deal with almost all the decisional stages of CMM inspection. Moreover, original approaches have been developed and presented in inspection feature selection, part set-up, probe configuration, and path planning.


Polimery ◽  
2021 ◽  
Vol 66 (1) ◽  
pp. 56-62
Author(s):  
Jadwiga Pisula

Properties of polymer gears were tested using coordinate measurement methods. This study is a follow-up to research on geometric accuracy of gears manufactured by injection molding. Spur gears were measured on a coordinate measuring machine running the GINA software by Klingelnberg. Measurement results were output in the form of measurement sheets which included values required in the DIN 3962 standard. The article also analyses the topography of test gear teeth. The topography was presented for a single tooth of the gear and determined on the basis of the measurements of 9 profiles distributed evenly over a specific profile assessment interval (interval Lα defined in the standard) and 7 tooth traces located within a relevant tooth trace assessment interval (interval Lβ defined in the standard). All gears tested in this study were placed outside accuracy class 12.


2021 ◽  
Vol 410 ◽  
pp. 872-877
Author(s):  
Andrey V. Kochetkov ◽  
Andrey A. Troshin ◽  
Oleg V. Zakharov

Currently the measurement of surface texture in mechanical engineering is traditionally carried out using profilometers. Modern profilometers do not allow measuring of surfaces with complex shapes. This is due to the different sensitivity of the sensor and the discreteness of the movements along the axes of the Cartesian coordinate system. Coordinate Measuring Machines are devoid of such a drawback. However, stylus of the coordinate measuring machine has a diameter many times larger than the diamond stylus of the profilometer. Therefore, there is a mechanical filtering effect, that affects the results of measuring the parameters of the surface texture. In this paper a mathematical model of the contact of the spherical stylus and a rough surface based on analytical geometry is proposed. Influence of the diameter of the spherical stylus on the maximum measurement errors of a amplitude parameters are investigated. Seven amplitude parameters Rp, Rv, Rz, Ra, Rq, Rsk, Rku of the surface texture are modeled. Coordinate measuring machine and profilometer with stylus diameter of 2 μm measurement results are compared. it was concluded that the stylus diameter of the coordinate measuring machine when measuring the surface texture should be no more than 20 μm.


2019 ◽  
Vol 9 (8) ◽  
pp. 1598 ◽  
Author(s):  
Fang ◽  
Huang ◽  
Xu ◽  
Cheng ◽  
Chen ◽  
...  

The probe tip of a micro-coordinate Measuring Machine (micro-CMM) is a microsphere with a diameter of hundreds of microns, and its sphericity is generally controlled within tens to hundreds of nanometers. However, the accurate measurement of the microsphere morphology is difficult because of the small size and high precision requirement. In this study, a measurement method with two scanning probes is proposed to obtain dimensions including the diameter and sphericity of microsphere. A series of maximum cross-sectional profiles of the microsphere in different angular directions are scanned simultaneously and differently by the scanning probes. By integrating the data of these maximum profiles, the dimensions of the microsphere can be calculated. The scanning probe is fabricated by combining a quartz tuning fork and a tungsten tip, which have a fine vertical resolution at a sub-nano scale. A commercial ruby microsphere is measured with the proposed method. Experiments that involve the scanning of six section profiles are carried out to estimate the dimensions of the ruby microsphere. The repeatability error of one section profile is 15.1 nm, which indicates that the measurement system has favorable repeatability. The mainly errors in the measurement are eliminated. The measured diameter and roundness are all consistent with the size standard of the commercial microsphere. The measurement uncertainty is evaluated, and the measurement results show that the method can be used to measure the dimensions of microspheres effectively.


Author(s):  
D Aitchison ◽  
R Sulaiman

The market for foam materials has been growing rapidly throughout the world as they have a variety of uses. Some examples are in the automotives industries, food packaging industries, medical application, sports gears, home insulations and floatation in offshore drilling rigs, buoys and small boats. Since the uses of foam affects greatly the daily lives of humans, the need to have foams in different shapes requires speed in cutting and manufacture. This can only be done through computer aided cutting machines or automated cutting of foams. However, the speed of cutting will affect the surface finish of the cut. Therefore, it is necessary to determine the surface form of the polystyrene to achieve quality results. This is an on-going research to produce a rapid-prototyping machine that cuts foam models. The first phase of this research is to determine the surface form of polystyrene through the use of a coordinate measuring machine (CMM), after being cut with different types of wires, at different temperatures and cutting feedrates.


Author(s):  
Haitao Zhang ◽  
Shugui Liu ◽  
Xinghua Li

REVO five-axis system, designed for the orthogonal coordinate measuring machines, must be reconfigured for the application in the non-orthogonal coordinate measuring machines. First, in this article, error sources of the system and components of measurement data are analyzed; then, scale values of coordinate measuring machine axes, which are essential to derive the coordinates of measured points in non-orthogonal coordinate measuring machine, are separated out. Besides, the mathematical model of REVO is established based on the quasi-rigid body theory, from which the measurement results can be evaluated by data derived instead of that returned by the system. The effectiveness of both separation of scale values and mathematical model of REVO is proved by experiments and practice. The research of this article is of great significance to the application of REVO five-axis system in the non-orthogonal coordinate measuring machine.


2013 ◽  
Vol 561 ◽  
pp. 572-575
Author(s):  
Zhao Lin Han ◽  
Mao Xing Yuan

When we use Coordinate Measuring Machine to measure some points of the workpieces, the wrong measuring method will get the poor repeatability and poor reproducibility of measurement results. Now the vector measure of the CMM is a more convenient way. The main principles are analyzed in this paper, and a workpiece is measured for example.


Author(s):  
Frank Ha¨rtig ◽  
Christian Keck ◽  
Karin Kniel ◽  
Heinrich Schwenke ◽  
Klaus Wendt ◽  
...  

The German national metrology institute, the Physikalisch-Technische Bundesanstalt (PTB), has developed a novel calibration method for gear artefacts. This reduces the current calibration uncertainty of gear standards, which is an essential step towards meeting the rising quality demands of the gear manufacturing industry. The measurement setup is based on a coordinate measuring machine (CMM) equipped with a high-precision rotary table. The key element of the novel gear measuring device is a tracking interferometer (TI) for reading the distance information. This information is combined with the reading of the coordinate measuring machine line scales in order to reduce the overall measurement uncertainty. If an optimized measurement strategy is applied, the measurement results are almost achieved with laser interferometer accuracy. First simulations and measurement results for an involute profile artefact are presented and discussed.


2014 ◽  
Vol 945-949 ◽  
pp. 2121-2125 ◽  
Author(s):  
Xue Liang Zhao ◽  
Yun Shi ◽  
Kang Li ◽  
Guang Hua Wei

The high precise pH automatic monitoring measurement is designed based on MSC1210 MCU and pH sensor. To eliminate the effect of temperature on the measurement results, a pH value temperature compensation module is established using the least Squares Method to analyze the linear relationship between pH and voltage. The results show that, the automatic monitoring measurement possesses broad application prospects with the advantages of ultra-low power consumption, good stability and high precision.


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