(June 6, 2011) The world needs clean energy like wind power, and the wind-energy industry needs affordable, top-quality wind turbine blades. The Department of Industrial and Manufacturing Systems Engineering at Iowa State University is using a 3D Digital Optix 400L laser scanner to help solve that need. When you see wind turbines high above Midwestern fields, it’s a pretty sight. But the reason you can see them from such a distance is their mammoth size—one blade is about 40 yards long and weighs over 10,000 pounds. One viable material to build them with is fiberglass, but it’s labor-intensive to make these blades, so manufacturing has traditionally been done in low-cost venues outside the U.S—but then they’ve got to be shipped.
At Iowa State’s Wind Energy Manufacturing Laboratory (WEML), the big problem to solve involves the placing of fiberglass fabric into their molds, which can be a difficult process to execute without getting wrinkles to form. Our graduate students are using the 3D Digital Optix to capture a point cloud of the fabric when we place it in molds. This gives us a three-dimensional picture of the small disturbances on the surface of the fabric. As we continue to capture this data, we hope to develop automated methods for placing and manipulating the fabric; which could speed up the process, reduce labor and related costs. The scanner is also critical in the process of understanding the final quality and finishing requirements for the turbine blade, which needs to be long, strong and very smooth (wind blades are essentially acting like wings on an aircraft). In checking for quality, we point the scanner so it gives us the “wind’s eye view” of the blade; which will hopefully tell us where quality challenges come from, and what upstream processes need to be improved.
I was introduced to 3D laser scanning at Penn State, where my PhD dissertation advisor introduced me to reverse engineering and rapid prototyping using this new technology. Early use at Iowa State for the Optix scanner was in a project for the rapid manufacturing of service parts for agricultural equipment; research in a subtractive rapid prototyping process called “CNC-RP”. The idea was to be able to deliver fully functional service parts for perhaps decades-old equipment that is still in use (a challenge for both agricultural and military equipment, in particular). This is necessary when the parts are unavailable, would require long waiting periods, or would require extensive inventories in warehouses — perhaps not acceptable when a crop needs harvesting right away or costs are prohibitive. In one example, we created a linkage for a harvester, scanning the failed component, importing it to a CAD program, modifying the file to “fix” the broken section, then rapid machining the actual new part in-house. From arrival of the failed part to boxing and shipment of the new steel part was 48 hours total.
We have a competitor’s scanner also in use at our department. It is sufficient for introductory teaching and demonstrations. I wouldn’t bring our Optix 400 into the classroom where large groups of students will have their hands on it continually; however, I don’t use the competitor scanner in our research lab for technical R/E and prototyping, either.
Dr. Matthew C. Frank, PhD, Assoc. Professor
Industrial and Manufacturing Systems Engineering
Iowa State University