Bottle Opener Day(s) 2.5: 2/4/2015 - 2/6/2015

Evolution: From Jellyfish to Bee

Over the past few days this week, we worked on our Jellyfish model.  With much help from Larry, our machinist, we were able to get our designs printed out. Continuing from my last post, Olivia and I had left the lab confused as to why the laser cutter was not printing out our designs. After our first attempt, Larry went back to check our DXF and SolidWorks files and emailed a photo of our product to us. Apparently, we were not too careful about setting up units in SolidWorks--the reason why the squiggles weren't displayed on the first attempt!

The head definitely fits over the entire bottle cap and the size of the Jellyfish is larger than it should be. We did not set any units in our first DXF file, and Corel couldn't read it entirely. Over the next few hours, I worked on lowering the head and setting the dimensions on SolidWorks. After a while...

Attempt #2: The Old Phone Jellyfish

 

I am definitely not proud of this second attempt. We cut this one, and all other attempts after, out of the 3/16'' sheet of Delrin. The pointy end has no function, and although I want to say that I have forgotten what I wanted to do with the pointy end, I still do remember. Could I possibly pry the bottle cap open with a sharp end? Naaah. If I wanted to fully develop a product with such a function, there would need to be another end from the top to stabilize the bottle and act as a fulcrum. It was a silly add-on idea, but it was nice to learn more functions on SolidWorks to create the sketch. The half oval itself was also a disappointment though; although I had set the dimensions for sketch and measured some of the parameters, I was not careful enough. I did not know of the existence of the "Measure" function on SolidWorks yet, and had been eye-balling the dimensions from the ruler above. The semi-oval from this product was exactly the same size as the semi-oval from the first product! :( 

Attempt #3: The Tragic Jellyfish

Lucky number three wasn't lucky at all. Cutting the Jellyfish out from the 3/16'' sheet of Delrin again, we collided with empty space from another person's cutout...so, our Jellyfish lost some of its ovalness. This attempt turned out to be a little too small. Although I measured the width and length (3.1 cm by 2 cm), the thickness of the Delrin made it impossible for the straight edge to fit underneath the bottle cap and for the conic section to rest on top. 

Attempt #4: The Almost Perfect Jellyfish

This was our final attempt before switching to a new model. The dimensions were finally right! The straight edge just barely fit underneath and the conic section rested on top of the cap. I pushed upwards and... realized that the cap wasn't going to give at all. Instead, the metal ridges of the cap stripped away at our straight edge. I tried filing down the sharp edges of the straight edge in hopes that it would get under the bottle cap a bit more and cover more under the curve, but the bottle cap kept stripping away at the straight edge.  The two resting points on the conic curve did not help much at all, because the concentrated force mainly relied on the tangent point that the cap made with the straight edge to open the bottle cap. If the bottle cap kept stripping at the straight edge, it wasn't going to make enough contact with the curve at all.

So, goodbye Jellyfish, swim back to your ocean, but we could no longer use you to open our bottle caps... 

Attempt #5: Bee Successful

Bee Successful! :) Mission complete: the bee bottle opener works! The night before Thursday, we designed another model in SolidWorks in case our original design did not function. To do this, we had gone back to our original sketches and found one of the models where we could 1) hold vertically instead of horizontally and 2) would serve as a lever. 

Originally, the sketch of our "bee" looked like this. After Olivia drew the figure out in SolidWorks though, she saw that the main function of the figure, its "mouth", could possibly be the mouth of a bee, and changed its shape. The engineering design process for this was slightly backwards, but we cut out a Styrofoam model of our bee after creating our SolidWorks model. The next morning, after our unfortunate Jellyfish still did not complete the task, we went to check the dimensions and printed out our bee Friday morning. 

It was so exciting to finally produce a functional bottle cap opener! It was even more thrilling that it continued to work and that we could easily apply a constant and significantly less force to push to the bottle cap over. The top of the bee's mouth to serve as a rolling fulcrum and stabilizer for keeping the cap in place, while the lower part of the bee's mouth went underneath the bottle cap that pulled up the cap's edges. Holding the bee vertically as we exert a force in an upwards motion, the bottom of the bee's mouth to exerts an upwards force underneath the ridges of the cap, opening the bottle.

We are ready to show our product to the class.

This was quite a long process! Thank you Larry for helping us print out our designs!