# An analysis of compensation for radial thermal errors of a turning center with a three axis feed system

## TL;DR

This paper introduces a three-axis feed system to reduce radial thermal errors in turning centers by compensating for spindle axis movement caused by thermal deformation.

## Contribution

The novel three-axis feed system is proposed to better compensate for radial thermal errors compared to conventional two-axis systems.

## Key findings

- The linear and angular components of radial thermal error are derived from the three-axis feed system.
- Locking the revolving feed axis allows the system to function as a two-axis system, improving tool tip alignment with the spindle axis.
- Simulation results demonstrate the effectiveness of the proposed system in reducing thermal errors.

## Abstract

Under normal cutting conditions, the cutting tool tip passes through the spindle axis when it moves along X axis during the whole turning session, however, which is difficult to realize for the turning centers with the conventional two feed axes due to the spindle axis movement caused by the thermal deformation of machine tool structures. Addressing this problem, a novel three-axis feed system is proposed in this paper. The effect of the thermal movement of the spindle axis on the radial thermal error is analyzed. The linear and angular components of radial thermal error are derived from the proposed three-axis feed system. The whole compensation process is demonstrated using a turning center equipped with this feed system, and the needed data is mainly from simulation. The effects of the parameter l of this feed system on the two radial thermal error components are analyzed. Furthermore, the three-axis feed system can also be used as a two-axis feed system by locking the revolving feed axis, which can make the cutting tool tip pass through the spindle axis easier than the conventional two-axis feed systems, and therefore it is helpful in both facilitating the adjusting or assembling process of the turning center and reducing radial thermal errors of machined parts.