Bottle Opener Part II.

Day 3

Professor Banzaert helped us make one part from the two parts of the handle and curved part that we made before and so we were finally able to create out bottle opener using the laser cutter!

SolidWorks drawing of our first prototype of the bottle opener

Laser cutter in action!

First Prototype

Our first prototype was a failure. The curved portion was way too large and could not hug the bottle cap at all to put any pressure down on it nor force up to remove the cap. We decided to make the curved part to be much smaller so that it could better hug the bottle cap. We also decided to make the thin part meant to be tucked underneath the cap to be a little thicker so that it would be less likely to break. We also decided to make the longer portion thicker as well.

Drawing of Prototype #2

Prototype #2

Our second prototype was also a failure. We thought we had the correct measurements. The space between the bottle cap and the curved portion should have been less than 1 mm but it was actually about 1.5 mm. We found that since we were using the thickest Delrin, the laser cutter had to go through the sheet three times. This would have caused the discrepancy between the SolidWorks measurements we had and the actual ones. This actually caused the thin nib part to be so thin that it broke the first time we tried to use it. Since this was a failure we decided to make a few more adjustments. We added 1.5 mm to top part, the curved part, and the nib part. We also added a little circle on the other side so that we could perhaps hang it on a  hook afterwards. 

Final drawing of bottle opener

Final bottle opener

And third time's the charm! It finally worked! My partner and I were elated! We couldn't believe it finally worked.We tried twice more just to make sure it wasn't simply luck and it still worked! The nib part got a little chipped after the first use but it was still able to open the bottle.

The goal of this first project was to create a bottle opener. We wanted to create a bottle opener that would be easy to use and would hopefully be able to withstand constant use. We used the idea of cantilevers to create our design. 

example of a cantilever

In a cantilever, the deflection, δ, is the amount of bending a beam withstands. It can be calculated using this equation:

F stands for the force applied on the cantilever/ bottle opener. L represents the length between the hand holding the bottle opener and the tip where the force is being applied. E is for Young's Modulus which is a constant property of the material. I represents the moment of inertia which can be calculated using this equation:

In order to minimize the deflection, we had to increase the moment of inertia as well as minimize the length. We did not want to have the length of the bottle opener too short because it would have made it too difficult to hold and twist up against the bottle cap. So we then focused on trying to increase the moment of inertia by making the nib part that went underneath the cap thicker by choosing the thickest sheet of Delrin which increased the base and a little longer which increased the height of the moment of inertia. The moment of inertia was increased just enough that our bottle opener was able to successfully open a bottle.

Evolution of our bottle opener

If we were given more time, we would have tried to make the design more aesthetically pleasing or interesting. We would have also tried to make it more pocket friendly so that one could attach it to their key chain. We would also improve on the nib part. It's still way too thin and will most likely break after a few more uses. If we had more time, we could have experimented a little more on trying different widths and heights for it as well as maybe using a different material for it, maybe a metal. But overall I'm proud of our bottle opener. I think that it's a nice little simple thing to look at and use and for now it at least still opens bottles.