Reflections on a Bottle Opener: Part I

Although I outlined the design process in previous posts, I did not cohesively summarize all the trials and tribulations that finally led to success.  Here's Part I of the reflection.
The first step of designing the bottle opener was brainstorming with my partner Laura to come up with some possible opening mechanisms.  After about 15 minutes, we came up with all of these ideas:

We started out with a half-moon shape with a handle on one end, and considered using teeth to grip the underside of the cap.  A simple wrench design seemed too flimsy, so we thought about making the handle much wider, or having a handle on both sides to minimize the stress on the part.  This eventually evolved into a design that was basically gripping the bottle cap with one's whole hand wrapped around the part, which would have indents oriented nicely for each finger.  We used a Pugh chart (shown at the bottom of the page in the picture) to compare our four favorite design, based on user-friendliness, manufacturing difficulty (how difficult it would be to draw on the computer), stress (how breakable it seemed), and aesthetics.  The hand-shaped design was our favorite, although we knew it would be difficult to draw the appropriate curves.
We toyed around with how this part would actually open the bottle.  We did have the crazy idea of designing something to simply punch through the metal on the top of the bottle, but we expected that Delrin would have a tough time with that, and so confined ourselves to the simpler task of merely popping off the cap.  With the hand-shaped design, we initially planned to have a circular opening, and wedge one half of it beneath the bottle cap and press down on the other half on top of the cap, to pry the cap off.  We thought about putting the whole part below the bottle cap and trying to use the glass part of the bottle as a fulcrum, but then we measured the angles and realized this would be much more difficult, so we decided to just put the hole halfway over the bottlecap.
We then went to make our foamcore "looks-like" model.  I traced my hand onto the foam and cut it out with an Exacto knife (which was more difficult than expected, but manageable).  At this point, Laura came up with another very similar design, which was slightly smaller and symmetrical (the design on the left in the picture below).  We suddenly realized that we weren't sure how large to make the middle hole, so we measured the bottle cap and experimented with a few different sizes.  We finally settled on an ellipse slightly larger than the cap, where pulled up on the part to rotate around the major axis to open the bottle.  We liked both designs and decided to start putting both into SolidWorks.