For measuring machines and machine tools, geometrical accuracy is a key performance criterion. While numerical compensation is well established for CMMs, it is increasingly used on machine tools in addition to mechanical accuracy. This paper is an update on the CIRP keynote paper by Sartori and Zhang from 1995 [Sartori S, Zhang GX (1995) Geometric error measurement and compensation of machines, Annals of the CIRP 44(2):599–609]. Since then, numerical error compensation has gained immense importance for precision machining. This paper reviews the fundamentals of numerical error compensation and the available methods for measuring the geometrical errors of a machine. It discusses the uncertainties involved in different mapping methods and their application characteristics. Furthermore, the challenges for the use of numerical compensation for manufacturing machines are specified. Based on technology and market development, this work aims at giving a perspective for the role of numerical compensation in the future.

Geometric error measurement and compensation of machines : an update

Thermal issues in machine tools

Machine tool feed drives

By synergistically combining additive and subtractive processes within a single workstation, the relative merits of each process may be harnessed. This facilitates the manufacture of internal, overhanging and high aspect ratio features with desirable geometric accuracy and surface characteristics. The ability to work, measure and then rework material enables the reincarnation and repair of damaged, high-value components. These techniques present significant opportunities to improve material utilisation, part complexity and quality management in functional parts. The number of single platform workstations for hybrid additive and subtractive processes (WHASPs) is increasing. Many of these integrate additive directed energy deposition (DED) with subtractive CNC machining within a highly mobile multi-axis machine tool. Advanced numerical control (NC), and computer aided design (CAD), manufacture (CAM) and inspection (CAI) help to govern the process. This research reviews and critically discusses salient published literature relating to the development of WHASPs, and identifies future avenues for research and development. It reports on state-of-the-art WHASP systems, identifying key traits and research gaps. Finally, a future vision for WHASPs and other hybrid machine tools is presented based upon emerging trends and future opportunities within this research area.

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Hybrid additive and subtractive machine tools – Research and industrial developments

On-machine and in-process surface metrology for precision manufacturing

R-Test, a New Device for Accuracy Measurements on Five Axis Machine Tools

Adaptive learning control for thermal error compensation of 5-axis machine tools

https://www.icvr.ethz.ch/ConfiguratorJM/publications/High_preci_141857146522533/CIRP_1_s2_0_S0007850614000328_main.pdf

High precision grey-box model for compensation of thermal errors on five-axis machines

In order to evaluate the configuration of machine tools, the IWF Axis Construction Kit (ACK) has been developed. This paper describes the evaluation of this approach. The ACK supports rigid body simulations and simple elastic body simulations. The ACK is compared with commercial FEM software to investigate its usability and reliability. Required time was compared in modelling of a machine tool. The ACK needed 30% of the total required time for the FEM because of its modularity in machine modelling. Then, in order to investigate the reliability of the ACK, static and dynamic simulations of both approaches were compared with each other and with analytical calculations on basic beam models. The result showed that the ACK provided equivalent results to the FEM. Static and dynamic simulations were also compared with measurements on an actual machine tool. The ACK obtained almost equivalent results to the FEM. Almost all lower structural mode shapes and their natural frequencies could be reproduced with the ACK when crucial parts were modelled using elastic bodies.

/pdf/evaluation-of-modelling-approaches-for-machine-tool-design-3u8s1io0e8.pdf

Sascha Weikert

Papers

R-Test, a New Device for Accuracy Measurements on Five Axis Machine Tools

Adaptive learning control for thermal error compensation of 5-axis machine tools

High precision grey-box model for compensation of thermal errors on five-axis machines

Evaluation of modelling approaches for machine tool design

Modeling and evaluation tool for supporting decisions on the design of reconfigurable machine tools