Measurement technology has always played a central role at the stamping and bending technology specialist Johann Vitz in Velbert. Managing Director Michael Vitz is convinced that the 3D multisensor coordinate measuring technology from Werth in particular secures a competitive edge for the family business.

The Videocheck IP in the QA measuring room has been updated several times, most recently with the TP200 probe and an articulation system. To the right of it is the WinWerth offline programming station.

With around 300 employees and over 350 modern production machines, Vitz manufactures springs, stamped and bent parts from round and flat material as well as shielding technology for the electronics industry. “Our specialty is the processing of hard and thin material from 4 mm up to 40 μm foil thickness,” emphasizes the managing director. The customers are mainly from industrial sectors such as automotive, telecommunications, household appliances, and mechanical engineering. According to Vitz, they appreciate “the flexibility and innovative strength of our company as well as the high quality standards of our products.”

He credits both his experienced employees and the high-quality production and measuring technology
for the quality: “State-of-the-art inspection equipment in the production and quality department are the basis for precise, individual and cost-effective product solutions.” His company has been working with measuring instruments from Werth Messtechnik for many years – originally to optically measure bent wire parts with high quality requirements. In 1989 the measuring projector Optimus was purchased for this purpose and it is still in use today. It differs from conventional profile projectors in its integrated “Tastauge,” a fiber optic sensor for fully automatic edge detection, which was introduced by Werth Messtechnik in the 1970s.

Optical measuring methods are of particular importance at Vitz – due to the product range, which includes many thin-walled and filigree parts. Contactless measuring avoids errors that could be caused by the part yielding during mechanical probing. In 1996, the Vitz managers invested in their first Videocheck S measuring machine with image processing sensor technology from Werth, followed by a Scopecheck S in 1999. “Werth has always been a leader in the field of optical metrology,” says Michael Vitz. “And when high-precision measurement results are required, there is no way around Werth. Because we have repeatedly found that these 3D coordinate measuring machines give us a competitive advantage.”

As an example, he cites the non-contact measurement of flatness on surfaces: “In this respect, we were already well advanced in the late 1990s with Werth image processing including zoom and integrated autofocus. We were able to measure flatness with high repeatability, which most of our competitors did not achieve.” This helped Vitz increase orders, especially in the area of shielding technology. For example, the specialists for stamped-bent parts won business to produce shielding plates for cell phones that had to have a flatness of 0.1 mm.

To be able to perform these and similar tasks even faster and more precisely, they invested in another Videocheck S 400 with two optical beam paths in 2002. In addition to the flexible zoom optics, a fixed optical beam path with a high-precision laser sensor is integrated for fast scanning. The high and long-term stable precision of this machine series is guaranteed by a unique guiding system. The preload of the bearing is generated by magnetic and gravitational force. This significantly reduces the internal friction of the bearing and thus minimizes the backlash of the measuring axes, resulting in a very small measuring uncertainty.

The highlight in the QA measuring room at Vitz is the Scopecheck FB DZ, a bridge-type measuring machine from Werth with two independent rams for optical and tactile measurement.

Tactile sensors complement the optics to use different processes in one machine
Christian Franke, Head of Quality Assurance, is responsible for the procurement and further development of measurement technology. He points to multisensor technology, a strength of Werth measuring machines: “Our first 3D coordinate measuring machines from Werth were only equipped with optical sensors. Soon we retrofit tactile measuring methods and from then on we only ordered multisensor machines. This is because the advantages of using different processes in one machine are of great importance to us.”

This allows the quality assurance staff to decide from product to product which features are measured with which sensor – depending on the required accuracy and which sensor can deliver results faster. Patrick Fornalik, one of four employees in quality assurance who work on the measuring instruments every day, confirms: “The beauty of multisensor technology is that we always remain in the same coordinate system, regardless of whether we are measuring optically or tactilely. There is no need for error-prone re-clamping to other machines or conversion of sensor positions.”

The market has made it clear to those responsible at Vitz how important exact measuring is in order to produce the articles correctly and to be able to meet the requirements of the customers (from left to right): Managing Director Michael Vitz, Christian Franke (Quality Assurance Manager) and Patrick Fornalik (Quality Assurance employee).

The measuring room as a central point for first article inspection and programming
Fornalik’s workplace is the QA measuring room, which today houses a Winwerth offline programming station, as well as the oldest of the existing Videocheck S 400. Purchased in 1999, Vitz had it repeatedly updated to the latest state of the art. First with the TP20 touch trigger probe, then with the Werth fiber probe, and finally when the TP20 was exchanged for a TP200 with an articulation system. “Werth supplies long-term precision mechanics and makes it possible to keep even the software of older machines up to date,” emphasizes QA manager Christian Franke. The Videocheck works with the current release of the Winwerth measuring software, as do all of Vitz’s other measuring instruments from Werth.

The second measuring instrument in the QA measuring room is the Scopecheck FB DZ 400, which was purchased in 2017 and is equipped with an image processing sensor including patented Werth Zoom optics with integrated Werth Laser Probe laser distance sensor. It also includes an articulation system for the SP25 measuring probe and two Werth Contour Probe tactile-optical sensors.

“This measuring machine in the fixed bridge design has two independent rams for optical and tactile measurement, which means that both measuring principles can be optimally combined,” explains Franke. While one sensor measures, the second ram remains in the park position outside the measuring range. This makes the geometries on the workpiece easily accessible from all sides – without any risk of collision. The retraction axis developed by Werth for the probe change rack makes it possible to change a wide variety of probes fully automatically without loss of measuring range. To do this, the change rack is moved from the parking position into the measuring range via the axes of the coordinate measuring machine and then parked outside again.

“We use the measuring machine mainly for our first article inspection,” explains Fornalik. “It measures very quickly, and thanks to the extensive sensor equipment and the large measuring range, we can scan even complicated components in all positions.” Fornalik and his colleagues also use the Scopecheck FB DZ to create measuring programs for the other 3D coordinate measuring machines from Werth that are used in production. “Our production staff and toolmakers sometimes need sophisticated programs that would be difficult to create offline,” says Fornalik. “Since our gantry machine is downward compatible with the other measuring machines, we find it much easier to program and do not block any capacity in the production measuring room. On the contrary, the FB DZ also acts as a backup in case a measuring machine fails.”

With the Werth Contour Probe WCP tactile-optical sensors, wave profiles can be measured very precisely.

In the production measuring room, the workers themselves measure to control the production process
The production measurement room is used by production staff and toolmakers at Vitz for running of the machines, for monitoring and controlling the production process and for changes to the tool. The equipment includes a Scopecheck S and two Videocheck S.

The Scopecheck S is mainly used for fully automatic measurements of connector contacts, which are produced in large quantities for the automotive industry. The Videocheck S from 2002 contains the fixed optics with the integrated Werth Laser Probe WLP, which makes it capable of fast, high-precision surface measurements in high point density.

Measuring machine number three is the latest Videocheck S 400, extensively equipped with the Werth Zoom and WLP, a measuring probe SP25M and two tactile-optical sensors Werth Contour Probe WCP, supplemented by a probe retraction axis and a parking station for the sensors. “We use this video check primarily for contour testing of a catalyst foil up to 270 mm wide and only 65 μm thick, which our customer uses in soot particle filters,” explains Fornalik. “We punch a wave profile and various holes into this foil. Thanks in particular to the tactile sensor, which can be positioned in workpiece coordinates because  of the multisensor concept, we are able to measure all features precisely, quickly and repeatably.” Fast means that the automated process now only takes 12 minutes. In the past, it used to take one full hour when every single contour had to be measured manually on a classic contour measuring machine.

The probe change rack for the WCP was retrofitted two years ago. Werth designed it in such a way that it is placed outside the measuring range and is only positioned within the measuring range for probe changing.

Reproducible measurement results optimize production
Managing Director Vitz uses the example of the catalyst foil to illustrate how important measuring in production is also from an economic point of view: “When setting up the die-cutting machine for the very tightly toleranced product, multiple corrections are usually necessary, which only take a short time thanks to the fast measurements by the operator himself. This greatly reduces machine downtimes.”

Measurement technology also pays off in production support and process control. The workers take random samples at certain intervals, which they measure in the production measuring room according to quality assurance specifications on the appropriate Werth measuring instruments. They recognize when dimensions change and can readjust accordingly.

Since the measurement data are regularly recorded and logged in a reproducible manner, those responsible also receive reliable information about long-term trends in the production process and can take appropriate measures. The data also serve as a reference for the customer.

The experience of the past few years has shown managing director Vitz and his employees how important exact measuring is in order to produce economically and to be able to meet the customers’ requirements. “As these are constantly increasing, we have to stay up to date in measuring technology as well. Probably our next investment will be in Werth’s computed tomography, which delivers complete 3D measurement data in just one measurement.”