Thermal error analysis for a CNC lathe feed drive system

Thermal errors cause serious dimensional errors to a workpiece in precision machining. A feed drive system generates more heat through friction at contact areas, such as the Linear encoder and the guide, thereby causing thermal expansion which affects machining accuracy. Therefore, the thermal deformation of a Linear encoder is one of the most important objects to consider for high-accuracy machine tools. This paper analyzes the increase of the temperature and the thermal deformation of a Linear encoder feed drive system. During temperature variation is measured by using thermocouples , meanwhile, the thermal error of the guide is measured by a laser interferometer. A thermal error model is proposed in this study by using back propagation neural network (BPN). An experiment is carried out to verify the thermal error of the guide under different feed rates and environmental temperature.

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Thermal Error Compensation without Temperature Sensors for CNC Machine Tools’ Feed Drive System

Journal of Mechanical Engineering ◽

10.3901/jme.2016.15.162 ◽

2016 ◽

Vol 52 (15) ◽

pp. 162 ◽

Cited By ~ 3

Author(s):

Kuo LIU

Keyword(s):

Error Compensation ◽

Machine Tools ◽

Thermal Error ◽

Temperature Sensors ◽

Drive System ◽

Cnc Machine Tools ◽

Cnc Machine ◽

Feed Drive ◽

Feed Drive System ◽

Thermal Error Compensation

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MODELLING AND ANALYSIS OF A STEPPER MOTOR DRIVEN FEED-DRIVE SYSTEM OF A CNC LATHE

Microcomputer Application in Process Control ◽

10.1016/b978-0-08-034340-2.50044-3 ◽

1987 ◽

pp. 237-241

Author(s):

B.E. Platin ◽

B. Çelik

Keyword(s):

Drive System ◽

Stepper Motor ◽

Feed Drive ◽

Cnc Lathe ◽

Feed Drive System

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Positioning error prediction and compensation of ball screw feed drive system with different mounting conditions

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/0954405416679444 ◽

2016 ◽

Vol 230 (12) ◽

pp. 2307-2311 ◽

Cited By ~ 12

Author(s):

Jun Zhang ◽

Bo Li ◽

Changxing Zhou ◽

Wanhua Zhao

Keyword(s):

Thermal Error ◽

Computer Numerical Control ◽

Drive System ◽

Numerical Control ◽

Ball Screw ◽

Positioning Error ◽

Positioning Accuracy ◽

Feed Drive ◽

Feed Drive System ◽

Screw Feed

For semi-closed-loop computer numerical control machine tool, the pitch error of screw caused by thermal expansion can deteriorate the positioning accuracy of ball screw feed drive system. This study presents different prediction models for positioning error of ball screw feed drive system based on the mounting condition, where the total error is separated into geometric error and thermal error. The coefficients in the model are identified using the multiple linear regression method. The prediction model is validated and the error compensation is also done for the X axis of a three-axis computer numerical control milling machine. The test results show that the model developed can well predict the thermal error under any given temperature as well as position during the temperature rising process of ball screw, and it can greatly improve the system positioning accuracy through compensation.

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