Evaluation of servo, geometric and dynamic error sources on five axis high-speed machine tool

TL;DR

This paper presents a method to evaluate how high-speed and high dynamic loads affect volumetric errors in five-axis machine tools, distinguishing static and dynamic error sources through experimental analysis.

Contribution

It introduces a novel approach to decompose geometric errors into quasi-static and dynamic components based on feed rate and structural deflections.

Findings

Dynamic errors increase with programmed feed rate.

Quasi-static errors remain relatively constant regardless of speed.

The method effectively separates error sources for better machine calibration.

Abstract

Many sources of errors exist in the manufacturing process of complex shapes. Some approximations occur at each step from the design geometry to the machined part. The aim of the paper is to present a method to evaluate the effect of high speed and high dynamic load on volumetric errors at the tool center point. The interpolator output signals and the machine encoder signals are recorded and compared to evaluate the contouring errors resulting from each axis follow-up error. The machine encoder signals are also compared to the actual tool center point position as recorded with a non-contact measuring instrument called CapBall to evaluate the total geometric errors. The novelty of the work lies in the method that is proposed to decompose the geometric errors in two categories: the quasi-static geometric errors independent from the speed of the trajectory and the dynamic geometric errors, dependent on the programmed feed rate and resulting from the machine structure deflection during the acceleration of its axes. The evolution of the respective contributions for contouring errors, quasi-static geometric errors and dynamic geomet- ric errors is experimentally evaluated and a relation between programmed feed rate and dynamic errors is highlighted.