Summary:

The objective of this design project was to maximize the vibration performance of the U222 mirror, or 2003 Ford Expedition mirror.  The goal was to have the minimum resonance frequency of the mirror be no less than 60.0 Hz.  The mirror must also pass the manual fold cycling test of 3,500 times.  Therefore the geometry of the mirror detent system cannot be change drastically so the wear increases significantly.

There was no clear solution to the problem, so a few of the concepts had to be built and tested to see which one would work the best.  The project required the designer to think of a solution, build a prototype, and then test the prototype.  If the design did not solve the problem, the designer must go back to the drawing board and come up with a new solution.  This process of coming up with a design, building the prototype, and testing the prototype was ongoing until the design solved the problem.

The final design came down to one of the concepts that was redesigned to incorporate solutions to problems that were encountered along the way.  The design of the bracket insures that the touch off points of the detent are on the outside of the detent system.  Changing the geometry of the detent was not enough to improve the vibration performance.  The compression of the spring increased the vibration performance to an acceptable level, but created another problem.  The increase of the spring load increased the wear on the housing.  The geometry of the housing had to be changed to minimize the wear.  The missing portion of the detent was filled in to give the detent more support.  Grease was also added to the design to minimize the wear and decrease the manual fold efforts to an acceptable level.  The final design maximizes the vibration performance of the mirror, and minimizes the wear to the detent system.