Numi, one of Kohler’s premium all-in-one smart toilets, allows users to adapt the experience to their personal preferences, from tinted lighting around the perimeter to wireless Bluetooth® music synchronization to a heated seat. Kohler plans to release Numi 2.0 this year, eliminating the need for hands-on control and offering personalized cleaning and superior water savings. With Amazon Alexa embedded, users can activate various functions by voice, such as checking the weather and reading the news.
While satisfying to consumers, all of these eye-catching features presented many challenges to designers and engineers. The internal design of the smart toilet is extremely complex, with dozens of embedded sensors and more than 600 components. Small changes in design can lead to major modifications to the entire project. Countless iterations were required before the world’s smartest toilet was introduced, sometimes requiring designers to make minor adjustments to the sensors and sometimes modifying the entire solution to accommodate functional adjustments. To prove the concept, Kohler had outsourced the CNC production of the prototype, but the whole process was time-consuming, especially quoting and negotiating, which was always a big problem. Design teams often had to wait more than a week, which made it difficult for designers to make timely changes and thus delayed the time to market. As a pioneer of innovation in the industry, Kohler certainly didn’t want to keep consumers waiting (and didn’t want to leave time for competitors to catch up).
In considering how it could speed up the prototyping process, Kohler turned its attention to 3D printing, the star technology of the Industry 4.0 era. Various technologies were considered, including SLS and SLA. From functional testing to part production Kohler Application Engineer Ms Irene worked with Elimold for the design and prototyping phases, respectively, for different purposes. Elimold’s 3d printing services are particularly useful when large parts need to be printed, such as toilet seats, because of the large sizes that can be printed and the manufacturing-grade materials that can be printed. Many parts, such as air ducts and nozzle holders, have been printed using ABS-M30, a material with strong layer bonding, high tensile properties, and impact and flexural strength. For parts that require high toughness, such as latches, Etc. Its high fatigue resistance is ideal for printing components that require rapid vibration. Most importantly, the FDM material can be used as a direct production pilot batch of end-use parts before mass manufacturing. This greatly simplifies the validation process.
With 3D printing, it is possible to perform different functional tests in line with industry standards, and 3D printing technology gives us a great deal of freedom.” When machining or milling, manufacturers must first break the prototype into multiple parts when it comes to chamber and cavity structures. In contrast, 3D printing allows complete models to be produced without breaking the prototype into parts. What took a week to complete can now be done in less than three days. This allows the team to focus more on improving the design and meeting the customer’s needs.
While the Kohler team worked with elimold to produce functional prototypes using tough materials, they also worked with elimold on more complex design validation. They needed to be able to take parts with different mechanical, optical or thermal performance requirements and print them for verification while simultaneously providing the Kohler team with more flexibility: to produce a complete product that would not require assembly after printing. Once the CAD files were created, the digital designs could be converted into actual concept models. These models contain smooth three-colour gradients, vibrant multicolour textures, elegant transparent colours or opaque creams that are identical to the intended final product.
The customer was particularly pleased with the parts printed using Veroclear, a transparent PolyJet polymer used in transparent acrylic simulations. The transparency of Veroclear and the high precision of the Connex3 printer allowed the Kohler design team to easily visualize the water flow within the toilet prototype to validate the concept prototype and make any necessary changes immediately. The GrabCAD software has a user-friendly interface that automatically presents the best layout. The Kohler design team can now focus more on the design process and get the job done better than before. Elimold’s solution has reduced the prototyping process by at least 40% and cut costs in half. After working with elimold, new ideas can be tried, such as using printed parts to test moulds and water temperatures. When equipment breaks, engineers can place an order to print threaded fittings to replace the damaged parts. After just six months, everyone in the lab has discovered that Elimold’s 3D printing services can be used for much more than they ever imagined.
The Kohler team hopes that elimold will be able to offer more solutions in the future and that the 3D-printed parts can be produced in high volume and become end-use parts. Before working with elimold, we couldn’t have imagined how easy the work could be. Now we can focus on the design process and get the job done even better.