ERA Charging Case
The ERA charging case came with a number of its own challenges, including the need for a solid and satisfying over-center mechanism for the rotating connector within a very tight space. We created breadboard prototypes in our shop to give us a first pass torque target for the over center mechanism. 2D CAD sketches at scale enabled us to quickly determine the maximum spring length differential within the available space. We then explored different approaches for the spring, including custom wire-forms that could fit around other required components. In the end, we fit a single extension spring that nailed the desired feel.
The next challenge was figuring out how to assemble that spring in a small space with limited access. We designed a small assembly fixture out of a couple of machined and 3D-printed parts for assembling our prototypes. It allowed us to sequentially secure the first end of the spring, tension the spring, and then secure the second end of the spring. The fixture worked so well, the design was carried over into production nearly verbatim.
Jawbone II 2008
Our first collaboration with Jawbone was for their Jawbone II headset. At the point we were engaged, the design was about to be released to tooling. We were able to flag a number of potential issues ahead of time, as well as provide extensive support on the ground in Asia during production refinement and ramp.
The effort involved balancing numerous competing constraints against a tight deadline. One key challenge was the main patterned cosmetic surface of the product, which served as a flexure for two different switches. Tolerance analysis and refinement of location features and assembly processes helped dial in the fit to where both switches passed a high bar for tactile response.