I like trying to make my class projects as practical as possible, like adding a hole to my laser cut box to make a pencil holder. So for this assignment, I decided to make my metal diamond a bottle opener!

 

To do this, I first had to determine the right geometry for a bottle opener and make sure it would fit on the diamond geometry. Rather than take measurements on a physical bottle opener, I found an amazon listing for a bar key, copied the image into Illustrator, and then sized the photo such that the width of the bar key in the image matched the width listed in the product description. Laying this on top of the diamond shape, I see it will fit well. So I recreate the shape with a series of lines and circles combined with the shape builder tool. Images of that process below.

Then I had to place the cutout on the triangle. I played around with the placement. Optimizing for a longer lever arm meant decreasing the thickness of the thinnest section of the part, and vice versa. I ended up choosing the longer lever arm version, planning to test the parts before doing any post processing in case I needed to change to the thicker section placement.

I selected a piece of .05” thick mild steel from the metal available in the wet lab. I chose steel because I thought aluminum would be too weak and would bend while trying to open a bottle. Also, similar openers online were made of stainless steel about the same thickness. Since this isn’t stainless, I knew I should plan to powder coat to protect the part from rusting. Here are the raw steel pieces after waterjet cutting.

As mentioned before, I wanted to test the parts before post processing to make sure they functioned. Here’s a video of me successfully opening a Topo Chico with my bottle opener diamond part. Yay!
(sidenote- I only know how to add videos as a link to download. Will try to figure out how to embed and will update if I can)

IMG_0192

Now for post processing! My plan was to file the rough edges off, then sand blast to prepare for powder coat, and then powder coat. I did all of that and it went great, until I opened the oven door and decided I wanted to check out how the parts looked before they had cooled. I grabbed one of my parts by the paperclip hanger, removed it from the oven rack, and the part fell off of the hangar and hit the oven floor, messing up the still-wet coating. Nooo!

I knew I had to sandblast the one I had messed up and start over. I wasn’t sure how easy that would be or if powder coating would look the same the second time around. So, in an effort to make the parts identical, I decided to sandblast and re-powder coat both parts. Sandblasting the powdercoat off wasn’t easy, and you can see I didn’t get them completely clean, but I figured it would be okay since I was using the same color again, and the distribution of left behind powder coat was similar for each part. 

After re-powder coating, you can see some of the left behind powder coat from the first attempt, since the color is translucent. I think it actually looks pretty neat, adds a bit of depth to the color. I am very glad I decided to sandblast and re-powder coat both parts- they would have turned out looking different from each other otherwise! Visualization of my process below (except for the messed up powdercoat, I panicked and quickly got the parts into the sandblaster without photographing the mistake).

Here are a few more shots of the finished parts.

 

Cost Type	Cost	Price	Source	Quantity	Total
Materials	Mild Steel 6”x18”x.05”	$14.93/piece	Home Depot	.5	$7.47
Labor	Waterjet Cutter Operator	$15/hr	Zip Recruiter	0.5hr	$7.50
	Powder Coat Operator	$15/hr	Zip Recruiter	1hr	$15
	Prototyping Engineer	$38/hr	Ziprecruiter.com	1hr	$38
Overhead	Facility Cost (Machine Time)	$13/hr	Dahlstrom	30min	$7
	Quality Control	$20.56	indeed.com	.25hr	$5.14
Total					$80.11