Wafflers that imprint interesting designs have become very popular, and Jarden’s Tilia subsidiary makes a variety of them sold under the VillaWare brand, including one that makes heart-shaped waffles and others that imprint the image of popular cartoon characters. In an effort to push the waffle envelope, the Tilia design team came up with the idea to develop a waffler that would imprint a bouquet of roses.

They wanted the rose bouquet waffler to produce the most beautiful waffles ever. The stated goal was to get the customer to say “Wow!” It would be the first waffler to incorporate a complex, three-dimensional pattern.

To achieve the desired aesthetics, Tilia hired a design studio to sculpt a bouquet of roses to serve as the model for the waffler surfaces. The design studio was more accustomed to meeting aesthetic than engineering concerns, so several iterations were required. The chief challenge for the artists was to sculpt a form with very specific geometric requirements regarding draft angles, overhangs, and undercuts. The waffle had to look pretty, but still must be easily extracted from the waffler without catching on the pattern and getting pulled apart. In that regard, the project was much like designing a plastic injection mold.

The final design exceeded the company’s expectations, but was so geometrically complex that engineers felt it would be very difficult to manually convert the form into the solid model geometry required needed to produce the mold for die-casting the waffler.

“It would have been very difficult for a CAD designer to duplicate the studio’s creation by hand,” says Jesse Patterson, mechanical design engineer at Tilia. “If we had asked one of our designers to take on this arduous task, the chances are they would have spent weeks or even months without ever capturing the beauty of the floral design. Today’s CAD software offers some 3D contouring capability, but not anywhere near the level that would be required to accurately capture a design of this complexity. A designer would have to capture tens of thousands of points with a coordinate measuring machine (CMM) to come anywhere close to depicting the beauty of the original design.”

In addition, using CMMs on parts is time-consuming because of the need to manually move the machine probe into position for each individual point to be measured. As the geometrical complexity of the part increases, the number of points needed to fully characterize the geometry skyrockets. Even if operators spend several weeks generating thousands of points, they can never be sure that they haven’t missed a critical feature.

Patterson was familiar with laser scanning technology, having used it on previous projects, and thought it would be the best way to convert the sculpture’s model to a CAD file. Laser-scanning systems work by projecting laser light onto surfaces while cameras continuously triangulate the changing distance and profile of the laser as it sweeps along, enabling the object to be accurately replicated.

Laser scanners are able to quickly measure large parts while generating far greater numbers of data points than touch probes without the need for templates or fixtures. Laser scanning can replicate the complete geometry of a complex part to a high level of accuracy, often to within a thousandth of an inch. The model can also be superimposed upon the original design geometry to determine exactly where they differ.

Because there is no probe on a laser scanner that must physically touch the object, the problems of depressing soft objects and measuring small cavities are eliminated. But with a relatively small number of parts that needed scanning every year, it made no sense for Tilia to buy a laser scanner. The cost would have been high and the company would have faced the challenge of training operators and maintenance staff. They also would have faced the risk that the machine could become obsolete before it had paid for itself.

Patterson says that soon before this particular need arose, Tilia had begun working with GKS Inspection Services, a service bureau that offers laser scanning services on a project basis. “We originally found them on the Internet,” he says. “We were in a crunch and needed to quickly convert a physical object into a 3D-CAD design.”

On that first project, Tilia engineers found that GKS could meet their schedule and quality expectations. So when the waffler project came along, Patterson says it was natural to use GKS again.

“I shipped the model to them so that it arrived on a Monday,” Patterson says. “They scanned the parts and generated a point cloud in which each individual point was accurate to within 20 microns. The surfaces generated from the point cloud were accurate to at least 0.004 in. By Thursday they emailed me a 3D solid model of the waffle iron. We checked some of the surfaces and they were right on. Just as important, they had captured the organic beauty of the design, which would have been almost impossible by hand. The ability to translate this complex model into a CAD in just a few days for a very reasonable price played a key role in getting the product to market on schedule.”

“CAD software is great for defining structured geometry but it’s no match for the complex curves involved in reproducing a living object,” Patterson says. “Laser scanning provided the ideal solution to our problem by maintaining high accuracy while picking up all of the small details required to deliver an aesthetically pleasing and manufacturable product.”

Tilia used the solid models provided by GKS as the starting point for designing the die casting molds used to produce the wafflers. The appliance maker has produced six different variations on the design, some that are sold under its own name, and others for private label customers.

For more information email: info@gks3d.com