Day 2 - Bottle Opener

Since my old partner missed today, I got paired with a new partner, Carrie. Her idea was to make a bottle opener inspired by an oar; she used to row crew and thought there would be a fairly large market on campus for a bottle opener that looked like an oar. She also wanted to make a bottle opener which was small enough to fit on a keychain so people could carry it around with them just in case.

Picture of an oar

Foam Mock-up of Carrie's oar design

Notice how this device uses a different mechanism to open bottles. Instead of using a hook, which is useless after it chips, this uses a 3cm long curved edge to open bottles, which can still possibly be used after some slight chipping. Also notice how the curves on the device are different on each side similar to the curves of an oar.

However, this device was not as easy to use as my ideas from Day 1. So, we decided to combine our ideas. We made a new device inspired by the robustness and oar design from Carrie's bottle opener and my easy-to-handle design from Day 1 and created a hybrid bottle opener.

Foam Mock-up of our hybrid bottle opener

How this bottle opener is meant to be gripped

Our bottle opener in action

Note: this is just a preliminary mock-up. The main change we are going to make is the location of the bumps because the current placement is really awkward.

The handle length was a compromise between my long handle and her short handle. The length of this hybrid was long enough to fit my large hands but small enough to where there was not any extra space at the end that stuck out. We also made the support on each side thicker than Carrie's original because we did not want our device to snap in half while opening a bottle. When we made our foam mock-up, Carrie diligently measured everything to be a nice measurement (an whole centimeter amount) which helped us when we eventually diagramed it in SolidWorks.

After making our foam mock-up, we started to design our bottle opener using a computer program, SolidWorks. We decided to make the top part symmetrical, a departure from the oar inspiration because with the bumps the device really did not resemble an oar. We started our handle by first drawing a rectangle of correct dimension in SolidWorks. {It should be noted that from this point forward on this project, I worked without a partner.} Then I added the bumps, and finally took out all of the extra lines. The bumps on the side took a long while to diagram in SolidWorks. To diagram them, first I measured the length from the top of one bump to the top of another bump using a previous design of an ergonomic handle which fit comfortably in multiple sizes of hands. Using this wavelength, I drew vertical centerlines of infinite length to use as a guide. Using these, I drew 8 consecutive 3-point arcs in alternating direction of the same radius. This made drawing consistent arcs of the same size more precise compared to freeform as once I created my first arc, the next would easily set to the same radius. Finally, I deleted the guidelines and then used auto-dimension to set everything in place.

Diagram of bottle opener with guidelines

Diagram of bottle opener after guidelines removed

Diagram of bumps with the guidelines

Diagram of bumps after guidelines removed

Alas, after I cut it out of 1/4" plastic, it was unable to open a bottle of pop. To be thin enough to open a bottle, the plastic needed to be thinner, but to be thick enough to withstand the pressure, the plastic could not be much thinner, a conundrum which renders this design in it's current state not particularly useful. I tried sanding it down, but after trying it on a bottle, my work was chipped away. However, I learned a lot about how to diagram ergonomic bumps in SolidWorks and will use this knowledge to move forward as I try to create my top design (the fourth one) from Day 1 in SolidWorks.

Unsuccessful bottle opener in plastic

The next design I tried used a hook mechanism to open a bottle.  I also continued to be inspired by things that are easy to hold. I was even more motivated to continue my quest for the perfect ergonomic bottle opener after googling "ergonomic bottle opener" and only finding super fancy bottle openers in the first few pages of results. Using my fourth design from the previous day, I continued on my journey.

The second SolidWorks diagram was much easier to make even though it was more involved and the foam mock-up off which it was based was not made with precise measurements. After editing it more, I made the bottom part too small and when I printed it out on the laser cutter, it bent under pressure and was unable to open a pop bottle.

Second bottle opener- plastic edition

For my third iteration I made the part that goes over the bottle thicker and added a small bump. This hopefully will be thick enough to withstand the pressure. I also smoothed out the corners around the ergonomic bumps because sharp corners are against the ergonomic philosophy. After my design was cut out of Delrin plastic, I had other handle this bottle opener and they all found it fairly comfortable in their hand. [The picture below is without the smart dimensions which are so thickly defined that you cannot see my design well with them.]

Third bottle opener diagrammed in SolidWorks

Third times a charm

How to hold the bottle opener

The bottle opener in use

This design opened a bottle!

If I were to continue working on this project, I would like to have tested it until it broke to figure out how reliable this design is and where the weak spots are. I would assume the major weak spot in my design is where the foam broke when I made my foam model, but I really do not know for sure. I would also would have like to have tested it with different length and depth of finger grooves. The ones on my design seemed fine, but there might be a better fit out there. I also might make different sized grooves for different sized fingers, because my current model has uniformly sized grooves.

Day 1 - Bottle Opener

This blog is for my extradepartmental 160, Introduction to Engineering Class.
For the next few days we were instructed to design a bottle opener, cut it out of foam board, draw it using a computer program called SolidWorks, print it out on sheet plastic, and repeat the process until we had a working bottle opener.

I've never actually thought about the process of opening a bottle before this lab.
After thinking about the process of opening a bottle, I realized that the only bottle opener which I have used was this little metal device which looks similar to this:

However, this contraption only works because it is made out of metal and it has that nice bend in it.
As I was constrained to using flat sheet plastic, it would take a lot more Google searching and more thinking to come up with more ideas.

In all of our ideas, we were inspired to make our bottle openers easy to use and handle. A bottle opener, however pretty it may be, is useless if it is too cumbersome to ever be used.

Idea 1:
A key.

However cool the idea of a bottle opener that looks like a key is, it isn't doable given my constraints. To make it thick enough not to break, starts looking less like a key. Also, if it is small, it is also hard to handle in your hand; if it is big, it looks silly, which is contrary to the premise.

Idea 2:
A man.

To use, you hold his body and open the bottle with his mouth. His torso is the same size as my palm. I added arms and legs and sketched in features to make him look like a person. However, the problem with this idea is that it is not as robust as other designs. Opening the bottle depends on the sharpness of the plastic around his mouth; once you open a few bottles, the plastic might start to erode, causing the device ineffective.

Idea 3:
Easy General Use 
{picture of sketch to come}
This idea could work. However, the main functionality is in the three-dimensional handle, which is impossible to do in sheet plastic. We would need to do something like wrap the handle in duct tape. However, without the handle, it is just a boring, normal bottle opener, which is against the spirit of this lab.

Idea 4:
Ergonomic

After making the first three ideas, we went to different teams and showed eachother our ideas. One team had a bottle opener with holes in it for fingers, and this design was inspired by their design. However, we only used that idea as a springboard, because holes that are big enough to fit my fingers might be too large for another person to use comfortably and too small for another person fit her fingers in. But, I thought that bumps instead might be a better option because bumps discriminate on less dimensions. My lab partner, Deepika, and I also tried out this option and even though my fingers are considerably fatter than hers are, it was still comfortable for both of us. (However, we didn't try with anybody with bigger fingers. If it doesn't fit bigger fingers, we could call it a women's bottle opener. We are at Wellesley after all.)

After sketching we cut the device out of foam board.

Our first mock-up was a great first attempt. We learned from this foam that the part that goes on top of the bottle cap needs to angle down a bit to open the bottle easier. Also the part that goes under the bottle cap needs to be bigger as this one crumbled quickly and was hard to keep under that bottle cap.

After making many other mock-ups too pitiful to post here, our last mock-up looks like this:

All of the mock-ups had essentially the same handle. However, note the difference in the top curvature of the device. The only thing that worries me about this new mock-up is that a weak spot exists, as demonstrated by our mock-ups braking in similar spots; this spot is right from the vertex of the angle up to the top of our bottle opener, a bad spot. This seems to be a design flaw because numerous new foam mock-ups all have the fault in the same place; however, it might be because this inner angle is hard to cut out of the foam using an exacto knife, in which case it shouldn't be a problem when using plastic.
We'll see on Day 2.