SUMMARY OF OUR DESIGN PROCESS:
1 Brainstorm
Kelsey and I sketched a couple of ideas and found the there are two main ways to make a bottle opener, 1) the one you apply the force under the cap and pull up to open and 2) the one you apply force on top of the cap and pull down to open.
2 Mock-up
And so we created a couple of the mock-ups from foam. (The last one is our final design but we made that after we finished! But just for comparison!)
3 SolidWorks
Next, we worked on SolidWorks to create our design which at first was difficult since we weren’t familiar with the software and the measurements sometimes didn’t go as planned but eventually it worked!
4 Redesigning the prototype
From trial and error, we redesigned the bottle opener 5 more times until we were satisfied with the result!
ENGINEERING ANALYSIS:
From the cantilever formula, which is that deflection is FL^3/ 3EI, we thought L is what makes the biggest difference to the deflection and the smaller the better. Also, although we cannot change the force applied to it (it might change depending on who uses the opener but not by much) and E, (Acetal’s Young Modulus: 2.6) we were able to change I by choosing different thickness of the material. (I=moment of inertia=BH^3/12)
So there are a few key points to our final design.
①Small L
This is the biggest reason behind our easy bottle opener. From the contact point under the cap and the cross-section we only have 7-8mm.
②Stiff material
By choosing the thickest (¼’’) we were able to make the bottle opener as stiff as possible so it could withstand the steel and wouldn’t break from the force. This allows us to have a bigger I.
③Round Design
The round design enabled the force to be stretched upon the top of the bottle opener which allows not too much force to be focused at one spot.
④Thumb Holder
To make it easier for the user to apply force, we made a place where you place your thumb and push so all of the force efficiently works towards opening the cap.
REFLECTION:
From our six prototypes, #1-6, we chose #1 in the first place from our brainstorm sketches because it was the simplest design and we thought it would be easier to create with SolidWorks. We made the bottom end pointy so it would be easier to go under the cap.
However, because it was too pointy it chipped when opening the bottle, although it worked so then we made #2 a little bit more longer with a not so pointy end. This is when we curved the top part of the opener to make the applied force smooth out. We also made the top part longer and thicker to make it tolerant to the force. (Because the design ended up being fairly small and a handy size, this is when we got the idea to add the hole to make it into a key chain so the user can carry it around.)
But, #2 also did chip a little, although it worked, but the biggest problem was the distance between the end and the point was too apart that it made it very difficult to open the bottle. So, for #3 we measured the bottle again and shorted the distance making sure it would work.
This is where we changed our design a lot. a) the size and b) the pointy end to almost a square end. For the size, we didn’t expect it to be this big until we printed it out. Because the pointy end for #1-3 kept chipping, although it was 1-2mm, we wanted a more sturdy opener so we made the bottom end closer to a square but with a slight angle. Also we made the thumb holder here.
There was only one problem with #4. Because the bottom end was too big and because of the right angle at the bottom, it kept hitting the bottle when we tried to open it. Also, the curved top part and the bottom end was too close so it did not work well. However, we decided to not go back to the small size because we were able to hold the bottle opener easier and we noticed it only required a smaller force compared to #1-3.
So then we made #5 fixing the distance between the top curved part and the bottom end which it did work but still we weren’t able to hook the bottom end below the cap smoothly because of the right angle.
Our last design, #6, finally, was when we adjusted the bottom end so it wouldn’t hit the bottle. We also made the ends of each corner much rounder to make it user-friendly, and we re-designed the thumb holder a bit deeper so it works better. Kelsey and I were both happy with how easy it was to open a bottle compared to our first few designs. Overall, I really enjoyed the process of re-designing and creating new prototypes after trial and error because you actually could fix the problems but each time new problems would come up so you knew things were getting better. If I had more time, I would make it a little bit more compact, maybe with less amount of acetal. Also, it would be nice to add some other functions to it like engraving measurements on the back so people can use it as a mini ruler.
