Hydroelectric power plants all over the world have been equipped with Voith Hydro components for over 140 years. As a full-service supplier of equipment for hydroelectric power plants, Voith is one of the world's leading manufacturers.
The company Voith Hydro GmbH & Co. KGheadquartered in Heidenheim, Germany, is a leading full-service provider of machine technology equipment for hydroelectric power plants.
In order to digitize components for which no CAD data is available, the company uses the scanner HandySCAN 3D and the photogrammetry camera MaxSHOT 3D from Creaform.
The reverse engineering project
The aim was to rebuild a missing filler piece for a guide vane, and to assign an existing filler piece to the correct guide vane. Guide vanes are components of the distributor. They control the volume of water and direct it onto a turbine wheel in the desired flow direction.
First, photogrammetric measurements were taken on the two guide vanes using the optical coordinate measurement system. MaxSHOT 3D to increase scanning accuracy and enable the scanning process to be carried out flexibly. The MaxSHOT 3D system offers a measurement accuracy of over 0.015 mm/m, and is ideally suited to large projects and parts from 2 to 10 m in length, enabling highly accurate measurements.
Next, a scan was performed, in which the existing filler piece was digitized. The scan file must represent as accurate an image as possible (in the order of 0.1 mm) of the wing contour, to enable accurate assignment and reconstruction of the filler parts. Scanning and processing of scan files is carried out using VXscan. By removing redundant or accidentally captured areas and then saving them as .stl files, the software also cleaned up the model.
In order to obtain a complete CAD model, it was necessary to carry out a surface reconstruction. This operation was carried out in Polyworks Modeler. The polygon models generated from the scan files serve as the basis here. During processing, CAD images of the filler part and its equivalent were generated on the guide vane.
The scan files of the guide vanes and the filler were also used for the "digital fit test". Here, the scan files were merged in Polyworks Inspector to find out which blade the existing filler belonged to. The same was done with the new filler to ensure it matched the guide vane.
Advantages of portable measuring instruments
"In the hydropower sector, many of the free-form surfaces used are difficult to measure using conventional measuring instruments. In order to be faster, more efficient and more flexible, as well as to obtain the benefits of reverse engineering, we decided to use Creaform's digitizing technology," explains Daniel Roessler, quality engineer at the Voith Hydro Group division.
In the past, the company used various portable measuring devices and 3D measuring arms. Creaform's HandySCAN 3D is much more flexible and free-flowing than a measuring arm. The dimensional range of components in the hydropower sector extends from 500 mm to 7000 mm. It is essential to use a portable system that can grasp the desired areas without having to constantly reposition itself. In addition, the previous system could only capture small areas. In comparison, the Creaform system works quickly and efficiently, and can therefore also capture large areas.
Mr. Roessler continues: "In our field, we need mobile devices that can be used flexibly and are ready for use without too much effort. With the HandySCAN 3D and the MaxSHOT 3D, we have two products that enable us to react quickly and flexibly at the customer's site, in the power plant, at suppliers' sites, and in the workshops".
Return on investment
It would certainly have been possible to carry out some of the measurements using manual measuring equipment, from which the filling piece could have been allocated and a new one built. However, it is highly likely that the newly manufactured filler piece would have had to be ground manually afterwards, as the free-form contour cannot be recorded using conventional methods. The components would then have to be transported from the power plant to the Voith factory, which would involve additional costs and effort. Thanks to scanning technology, only one person was needed to carry out the scanning on site at the power station. Thanks to the digital images of the components, the remaining steps could be carried out digitally on a PC.
In principle, a time and cost saving potential of 40 to 50 % can be achieved by using reverse engineering for components with a medium level of detail compared to standard engineering. The advantage here is that after a scan, all profiles and measurement data are complete in a single file, and tedious re-checks on the component are no longer necessary. What's more, the potential risk of erroneous manual measurements and misinterpretations is reduced to almost zero. The location of the component is irrelevant when using laser scanning. With Creaform handheld devices, Voith Hydro is able to capture details anywhere and in almost any position.
A positive result on all fronts
"Practices and processes have improved, especially in terms of what is possible. Thanks to HandySCAN 3D and MaxSHOT 3D, Voith Hydro is able to react flexibly and quickly to tasks or problems. Components can be digitized and examined or rebuilt on a PC in no time at all. Responsiveness is an important feature that Creaform systems make possible. In production, in the service area or on construction sites, situations often arise that require an immediate response, and long waiting times are often accompanied by high costs. With our Creaform systemsWe are able to offer the customer an immediate solution and analysis," sums up Mr. Roessler.
"Creaform has sophisticated systems for digitizing components. Thanks to Creaform's products, we are able to accurately measure and digitize our customers' components quickly and cost-effectively for the future, especially those from past manufacturing years, when digitization did not yet play a role. What's more, we can manufacture components individually as required".
About Voith
Voith is a globally active technology group. With its broad portfolio of equipment, products, services and digital applications, Voith sets standards in the energy, oil & gas, paper, raw materials, transportation and automotive markets. Founded in 1867, Voith is today one of Europe's leading family-owned companies, with over 19,000 employees, sales of €4.3 billion and sites in more than 60 countries worldwide.
Group division Voith HydroVoith, headquartered in Heidenheim, Germany, is a leading supplier of complete hydroelectric power plant equipment and a reliable partner. Voith develops individual long-term solutions and services for large and small hydroelectric power plants worldwide. With its portfolio of products and services, the company covers the entire lifecycle and all components of hydroelectric power plants, whether large or small: from generators, turbines, pumps and automation systems to spare parts services, maintenance, training and digital solutions for intelligent hydropower.