For our Design, Tolerancing and Prototyping project, our team designed a phone case modeled for an iPhone 8 Plus that has wallet attachment in the back with cascading mechanism.

Problem We are Solving

By merging phone case with a wallet section, our product allows people to keep their important items like credit cards, IDs, and their phone all in one place. Current phone case wallet attachments in the market make individual cards difficult to remove, but our design  has cascading mechanism that pushes each card at a different height so that each individual cards can be taken out easily and conveniently. The user of our product can protect their phone from drops with phone case while keeping all their belongings in our easy access wallet attachment.

Design Decisions 

We began designing our product by thinking of ways to improve wallet attachments on phone cases with the goal of making card access easier. This vision eventually led to the idea of a cascading mechanism that pushes cards at different heights. We decided to limit the number of cards in the case to 4 to make sure the case is not too thick and can go into the pocket easily. Although we were originally going to design our whole product as one single piece, we then decided to design the phone case and wallet attachment separately for the ease of manufacturing. After each pieces were manufactured separately, we glued the wallet attachment onto the back of the phone case. This strategy improved the tolerancing of our product and helped us get a fine finish as well as tolerancing. 

How our Prototype Works 

Our phone case component works as a standard phone case, designed with a 0.1 mm of clearance. The case thickens around the corners of the phone to provide extra protection around its weakest points. The case create openings for speakers, charger, camera, and exterior buttons on the phone to be used while still protecting the phone. The wallet attachment is designed to hold 4 credit cards and is super glued onto the back of the phone case. It has a knob that turns a cascading mechanism component with circles of different radii that push the cards in the wallet out at different heights to allow for easier access. Our product created a safe environment to store cards and easily retrieve them, fitting each card with .04 mm clearance. 

Manufacturing Decision

We 3d printed our product using onyx as the material because it is hard and durable which is perfect to protect the phone from impact. Also, onyx is beneficial in terms of tolerancing. However, if we were to mass produce the phone case, a method we would likely adopt for the phone case is injection molding since it is better suited for mass production because of the reduced cost and reduced manufacturing time. 

Future Plan

Even though our product proved to be very productive and helpful for the users, there is always room for improvement. For future design, we plan to increase the spaces for credit cards to make it easier to slide along with the mechanism. We can work on expanding the cascading mechanism to push the cards out further. Since users carry money in their wallet, adding a money clip on our wallet attachment for cash will enhance our product's use. Overall, our goal is to make the attached wallet as user friendly as possible while maintaining the durability of the phone case.