Éocycle Technologies

There are many decisions to make when you carry out an inspection project, mostly with regards to which hardware and software should be used. During service projects for customers, Creaform metrologists use relevant tools in order to make sure that their time is optimized, and sometimes they can even use partner technology along with Creaform products. This happened during the Éocycle project, a designer and manufacturer of permanent magnet electric generators and motors, when Creaform had to inspect two casts used to make wind turbine blades. More specifically, these casts were used to make the two sides of the blade, the internal and the external one.

The customer wanted to investigate whether the casts could be causing the variable performance of some wind turbines, which was sometimes lesser than expected. According to the customer, if the blade had a profile that differed from the theoretical model, it could cause the observed performance variations. And since the blade conformity essentially depended on the conformity of the casts in which they are made, Creaform had to verify the tridimensional geometry of the casts by comparing it to the 3D engineering plans.

The casts were made of fiberglass, and were not very rigid, due to their extremely elongated shape. They were about 6 m (20’) long, and only 61 cm (2’) wide at their largest part. The thickness was less than 12 cm (6”). The casts are mounted on a steel structure to make their more rigid, and to ensure that blade production is uniform. The inspection had to reveal any geometrical non-conformity, and before the surfaces were scanned, the casts had to be matched to their structure, and the setting as a whole had to comply with the drawings.

The 1st step consisted in conforming the two casts with a laser tracker. The edge of the blade had to be as close as possible to the 3D drawing. The structure was adjusted manually in several places. Once the customer accepted the actual deformations, these adjustments were considered final and the attachment points were welded in place.

The 2nd step was to acquire the 3D referencing model with the MaxSHOT 3D, an optical coordinate measurement system from Creaform. After affixing reflective targets on both the structure and the cast (which form a single rigid body), the metrologists simply took many pictures under different angles, and used VXelements to build the precise model.

The final step was to scan the casts in high resolution with the Creaform optical CMM scanner: the MetraSCAN 3D. The process only lasted for a few minutes, and then all that remained to do was to compare the actual measurements with the theoretical data while using the PolyWorks inspection software, which offers quality colorimetric results.

Using all these technologies made it possible to optimize the inspection and report creation time. In the end, Éocycle Technologies concluded that the casts indeed complied with the theoretical geometries, within acceptable tolerances