A study on thermal displacement of CNC horizontal lathe based on movable component temperatures

ABSTRACT

This paper presents a thermal error model for a lathe CNC machine using temperature on moving parts, which is usually a difficult measurement. Different working conditions are performed to obtain temperature and thermal displacement of the machine. A multi-linear regression model is applied for modelling relationship between temperatures and thermal errors. Data of two constant working conditions are implemented to find out the fitting function. Through analysis, it shows that thermal errors for X- and Z-axes can be estimated based on only four temperature points (T₂, T₃, T₁₀ and T₁₂ for the X-axis and T₄, T₆, T₇ and T₁₁ for the Z-axis). Results reveal that using movable part temperature data (T₁₂), the average and maximum error in the predicted thermal displacement of the X-axis can be reduced about 1/3 and 2/5 compared to without using T₁₂, while the movable temperature point on Z-Screw (T₈) has a tiny effect on the average and maximum error of predicted thermal displacement of the Z-axis. Results herein can provide useful information to develop a thermal compensation for the CNC lathe machine.

KEYWORDS:

• CNC lathe
• thermal compensation
• movable temperature point
• linear regression

Acknowledgments

We thank for the subsidy of the Outlay MOST 109-2221-E-035-006-MY2 by the Ministry of Science and Technology, the Republic of China, to help us finish this special research successfully.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article. Raw data that support the findings of this study are available from the corresponding author upon reasonable request. https://docs.google.com/spreadsheets/d/1l5mu7rPkP3dI0cdXvJS3nZa5yq2SePoE/edit?usp=sharing&ouid=114409146108025392532&rtpof=true&sd=true

Additional information

Funding

This work was supported by the Ministry of Science and Technology, Taiwan [MOST 109-2221-E-035−006-MY2].

Notes on contributors

Van-the than

Van-The Than received his Ph.D degree from Ph.D Program of Mechanical and Aeronautical Engineering at Feng Chia University, Taiwan. He was a research fellow in College of Engineering at Feng Chia University, Taiwan in 2017. Currently, he works at Hung Yen University of Technology and Education. He works on thermal problems, inverse method, numerical simulation, and high-speed spindle.

Thi-Thao Ngo

Thi-Thao Ngo received her Master degree from Hanoi University Science and Technology, Vietnam and Ph.D Program of Mechanical and Aeronautical Engineering at Feng Chia University, Taiwan. Currently, she works at Hung Yen University of Technology and Education. Her researches focus on heat transfer problems, inverse method, numerical simulation, and welding technology.

Ding-Yuan Su

Ding-Yuan Su received his master's degree from the master's Program of Mechanical and Computer-Aided Engineering at Feng Chia University, Taiwan (2021). His interesting research includes mechanical engineering, thermal problem in CNC machine.

Chi-Chang Wang

Chi-Chang Wang received Bachelor, Master and Ph.D degrees at National Cheng Kung University, Taiwan. He is now a Distinguish Professor and Dean of College of Engineering and Science, Feng Chia University. He focuses on Thermal Design and Thermal Decision Making; Machine tool thermal design, fast heating and thermal displacement compensation technology; Sensor Design and Smart Decision Making