Hinge and snap-fit design confirmed by prototype project

Medtronic Xomed, a supplier of medical appliances for the ear, nose and throat, recently embarked on a project to improve the design of its disposable nerve stimulator/locator. The project’s goals included a 50% reduction in manufacturing costs, production of the product to six sigma standards and improvement of ergonomics and product appeal.

Medtronic assembled a team that included the University of Florida’s Integrated Product and Process Design educational initiative and DSM Somos, a supplier of materials for rapid prototyping technologies. The team initially focused on the manufacturing and assembly process, which required seven steps. To reduce the number of steps, the team prototyped a new design incorporating a clamshell with an assembly hinge and snap fits. The team used stereolithography and DMS Somos 8120 resin, a high-speed, liquid photopolymer epoxy, to test the functionality of the hinge and snap fits.

“The Somos 8120 prototypes were great,” said David Rumsey, one of the team members. “They were definitely more flexible than the previous prototypes, and the finish and color were much better.”

Flexibility in the hinges was critical. Testing on the prototype proved the viability of the snap fits, however the hinge assembly initially failed, and required a redesign.

The one-piece design reduced the number of assembly operations by 75% and eliminated secondary work. Additionally the cylindrical housing increases visibility and control, simplifying the installation of internal components.

DSM Somos 302-326-8109