Using Step Gauge (check master) to improve the positional accuracy of CNC Machin
Step Gauge improving accuracy of CNC
Step Gauge (check master) improves the accuracy of CNC Machine
Currently, many companies use Laser Interferometers to verify the positional accuracy of CNC machine. But, if the verification is conducted on the spot of the work shop with substandard environmental conditions, the result would not be precise because of the temperature, air current, humidity and etc. A field test has shown that the numbers are quite different between 09:00 and 15:00. while checking the accuracy of one machine on the same day.
To solve the problem, the Step Gauge (or Check Master) is applied to adjust the CNC Machine. The Gauge has the almost same expansion coefficients as the CNC Machines and is little affected by the other factors which could significantly cause inaccuracy while using the Laser Interferometers.
It is a misunderstanding that Step Gauge is outdated and is replaced by the Laser Interferometers. To check the accuracy of Coordinate Measuring Machine, both ISO 10360-2:2009 and GB/T 16857.2-2006 recommend the Step Gauge (or Check Master)
In 2011, a Gear producer in Nanjing purchased a 3m Coordinate Measuring Machine from Leitz (Germany), the Leitz engineers used a 1m High Precision Step Gauge to calibrate during the installation.
(1) Step Gauge VS Laser interferometers
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Step Gauge/Check Master |
Laser Interferometers | ||
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Accuracy |
Both have good accuracy in a standard laboratory. There are many factors affecting the accuracy of Laser Interferometers (temperature, humidity, material properties, and etc). And it requires a high technological competency of the operators. The accuracy of Laser Interferometers will drop once it is used outside of laboratory. Measuring results vary a lot between morning and afternoon. | ||
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Date Consistency |
The coefficient of thermal expansion of Step Gauge is same as grating ruler. Placed in the same environment with the to-be-measured machine to achieve same temperature, it will produce accurate results. The Laser Interferometers’ coefficient of thermal expansion is next to zero and is quite different from grating ruler. It is very sensitive to temperature change. Even with temperature sensor, it is hard to achieve accurate results. | ||
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Repeatability |
High Precision Step Gauge wins! | ||
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Data Drifting |
High Precision Step Gauge wins! | ||
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Stability |
High Precision Step Gauge wins! | ||
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Operator request |
One person with average technical skills |
Two person with special technical skills | |
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Portability |
Lighter weight, smaller size |
Bulky and heavy | |
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Calibration fee |
Low |
High | |
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Price |
Step Gauge is about 10% of Laser cost | ||
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Maintenance |
Easy & simple |
Costly | |
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Operating Life |
Step Gauge has a longer life. | ||
Author: Andy Wang
Date: 2013-12-20
Email: trade2@anyii.com
Website: www.anyimeasuring.com