Dual-Screen/QWERTY Smartphone Model

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(Click thumbnails above to see larger images; pictures courtesy of Eugene Wong.)

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Assignment for DAI406 (Model Development), taken in Spring 2008 at SFSU. The objective of this assignment was design and model a small consumer electronics device. Since I was already thinking ahead to my creative work project (equivalent of a Master’s thesis), I decided to continue in this vein and design a PDA/smartphone with features specifically for the deaf/hard-of-hearing population (specifically, a sound alert system). In addition, I wanted users to have the option of input via touchscreen (on-screen keyboard), as well as via a full QWERTY keyboard. I had to make some decisions: would the touchscreen be external or internal, and would the QWERTY keyboard be external or internal? For ease of use, I decided the touchscreen display should be external; to prevent accidental/unintended input, I decided the QWERTY keyboard should be internal. However, there was still the matter of how to expose the QWERTY keyboard for use when needed; I decided on a flip-top form factor, in which the top component of the smartphone would flip open to reveal the QWERTY keyboard. I chose this mechanism mostly because it was within the realm of what I could do insofar as model-making was concerned. However, this presented one practical problem: when flipped open, the touchscreen would be facing away from the user and thus not visible; this necessitated the addition of another (internal) screen, which would in theory be a conventional display. This presented its own advantage; the flipped-open touchscreen could mirror the internal display as the user typed, which could be used as a rudimentary means of communication between deaf and hearing users.

With all of these decisions made and some design drivers established, I set about designing the smartphone in Solidworks; screengrabs of the model and consequent drawing files are shown below:
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Part1 Part2

The manufacturing process was intensive and lengthy; one thing about the process that I feel bears mentioning is the hinge mechanism for the flip-top component. The components had to be sanded, finished, and painted before assembly, so the hinge had to somehow be incorporated at the end. What I ended up doing was sourcing a very small spring, which I inserted into the hinge channel in the top component of the smartphone. On either side of the spring, I inserted short pieces of 0.125″ brass rod; they needed to be long enough to stick out when the spring was fully extended, but at the same time, short enough that they could be flush with the sides of the top component when the spring was compressed. I used butter knives to force the brass rods flush with the sides, and then inserted the top component into the bottom component; when the knives were removed, the spring extended and forced the brass rod pieces on either side into the pivot holes in the bottom component.

The full Flickr set of photos of the manufacturing process is here.

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