Laboratory for production metrology



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Focus points of work

The laboratory is mainly used for teaching and supporting other laboratories as well as the operating workshop with metrological tasks. Research tasks are only carried out occasionally.
In the laboratory, measurements from the area of workshop metrology to complex measurement tasks such as in coordinate metrology can be carried out. The most precise measurements of tolerances up to measurement uncertainties of +/- 1 µm are possible. However, due to the location of the laboratory on the first floor (influence of vibrations of the floor) and the lack of air conditioning, such precise measurements are only possible to a limited extent.
Unfortunately, a regular return of the measuring equipment is not possible due to the tight budget. Various calibration standards exist for daily checks.

Project work and also final theses are regularly assigned in the laboratory. For example, AR technology (augmented reality) and other methods are currently being used to improve the preparation and execution of laboratory experiments for students. The goal is to enable students to efficiently prepare and increasingly independently conduct some suitable (not all) laboratory experiments through various channels.

Teaching

In the laboratory experiments, the students are taught principles of measurement technology and the necessary care in handling measuring devices and measuring equipment. The interpretation of measurement results also plays a major role. In addition, the students are taught the classification of production metrology in the production chain from the CAD model to the finished component. The experiment on the measuring arm is particularly suitable for this purpose, as is an additional task that the students have to work on independently. For this, the students are assigned a non-trivial component (e.g. a brake disc or a cylinder liner). The task is then to determine the required tolerances from a functional analysis. A measurement strategy must then be developed for these tolerances (what should be checked how often,where and with which measuring device). The measurement results are to be discussed in conclusion.

On average, 160 students from the PT, PS and WIM courses are supervised in the laboratory per semester. Due to the small size of the laboratory and the sensitivity of the measuring equipment, the students are guided through the individual measuring stations in small groups. This results in a high time utilisation of the laboratory during the lecture period.

The students are prepared for the laboratory in a four-hour introductory lecture at the beginning of each semester (e.g. embedding production metrology in quality assurance strategies, repetition of form, dimension and position tolerances, implementation and meaning of statistical process control SPC, etc.). Furthermore, experimental protocols are to be written in groups. Due to the large number of participants, the individual oral laboratory entrance examination has been replaced by a short written examination after completion of the laboratory experiments.

In addition to the German-language laboratories, there are annual English-language laboratories for incoming students (exchange students from foreign universities) from the XEN course with a comparable scope of experiments.

Equipment

Various measuring devices of workshop metrology (partly with computer connection via BT):

  • Digital callipers
  • Micrometer screws (external and internal, different measuring ranges)
  • Precision pointers with flat measuring table
  • Dial gauges
  • Various gauges

Mahr form tester MMQ40 with C-axis for checking the form and position tolerances.

Various mechanical surface testing devices:

  • Mahr MarSurf PS1 handheld tester (without evaluation of waviness).
  • Mahr MarSurf XCR 20 tester with MarSurf GD 120 feed unit (roughness and waviness)
  • as well as feed unit Perthometer PCV for contour measurement (e.g. thread, arc shape, etc.)
  • Optical surface tester:
  • Feed unit fine testing Perthometer PRK with Focodyn laser probe.

Coordinate measuring arm Faro Fusion (measuring sphere diameter up to 1.8 m)
Mounting option on tripod for outdoor measurements (e.g. car bodies, containers etc.)

Coordinate measuring device DEA global classic in portal design

Tooth wheel tester dwu zwg 1002 with master gear helical 27°, module 2.5

Multi-position measuring device with eight inductive probes (TESA) and SPC evaluation

Impressions

The team