We did a failure mode and effects analysis to understand the severity in which our mechanism can possibly fail. The purpose is to address those occurrences and take necessary actions to neutralize them from happening. While working on this, we also got a chance to get feedback from classmates working on other projects. It is interesting to get insights from an outsider perspective. It helps in understanding how they perceive it. We primarily focused on 4 main components of our alpha prototype namely the baseplate, the D clamps, locking mechanism and the dial torsional spring actuation.

One of the more critical potential failure modes was the D-flaps hitting the rider during the ride or while the rider gets on/off the bicycle. To address this issue, we iterated on the form of the D-flaps. In our proof of concept, we came up with a better solution while keeping in mind the rider’s safety. The clamps are replaced by the steel straps which are coated with PVC. This has not only made the product safe to use but also lightweight and sturdier as well as keeps the helmet safe from any scratches.

The other major concern that we had was the torsion spring losing its strength to control the D flaps in place. This would result in the helmet loosening when it is in a lock mode which would eventually result in falling off or theft. To address this, we realized the flaps mechanism had various technical issues which could render the mechanism futile. In our proof of concept we have a mechanism which is not based on the potential energy being stored in some form. It is a simplistic mechanism yet robust and foolproof.

Therefore, our FMEA informed our design decisions for the beta prototype in three ways:

1. Rather than have extrusions from the base plate that could potentially injure or obstruct the bike rider, we decided to keep the base plate flat and flush against the bike frame. The material securing the helmet itself would then be one that would not harm the user. In our case, we decide to cover our beta prototype in a soft foam, but in our manufacturing plan have made this a hard plastic that is safe for the user.

2. Instead of using a spring mechanism that could weaken over time, we focused on implementing a more reliable mechanical mechanism for adjusting the straps in the beta prototype using hinges.

3. Lastly, rather than mechanically introducing a new lock type, we recognize the importance of ensuring anti-theft and security measures do not fail and therefore have incorporate the installation of a third party verified lock into our design.