machine tool metrology
Course Content
The course provides basics to geometric errors: the definition of component errors, the definition of location errors, the procedure to define the coordinate system of the machine tool, the procedure to calculate the maximum number of potential geometric errors of a multi-axes machine tool. The theory is explained with practical examples.
Then laser metrology, a frequently used metrology device for machine tools, is discussed, the set-ups for positioning, pitch, yaw, and straightness measurements. The focus of this part of the course is the estimation of the measurement uncertainty and environmental influences to these laser measurements. Uncertainty estimates are explained with practical examples based on ISO methods.
Important geometric measurements for linear axes, rotary axes and spindles are described, like measurement of straightness error motion, angular error motions of linear and rotary axes, squareness error motion. This includes reversal methods for improving measurement uncertainty. Kinematic tests (e.g. circular tests, straightness test on lines in space) are presented and discussed.
Thermal influences on machine tools and their importance are presented, as well as test methods in order to identify influences from the environment, from rotating spindles and from moving linear and rotary axes.
Test pieces for different machine tools according to ISO are presented and explained, as well as the procedure for capability tests. Problems associated with these statistical evaluations are discussed, e.g. the influence of measurement performance to capability values.
Finally latest developments in testing machine tools, like multi-lateration with laser trackers/laser tracers, ball bar tests with rotary axes, chase-the-ball tests on 5-axis machine tools, and conical ball bar tests and conical test pieces for 5-axis machine tools are described.
For all tests presented relevant ISO standards are referenced.
Participant(s) Profile
- Technicians and engineers working in the field of machine tool metrology
- Students in the field of mechanical engineering
- Experienced researchers in the field of manufacturing
- Machine tool designers
Tutorial Outcome
- Knowledge of potential geometric errors of multi-axes machine tools
- Test methods for geometric and thermal machine tool errors
- Concept of measurement uncertainty and it’s effect on tolerances
- Latest developments in machine tool metrology
Brief CV(s)
Tutor 1: Dr. Wolfgang Knapp >>>