Hello!!
These past days we have been working on the plasma cutter module and we were assigned to fabricate two diamond shapes with whatever design we wanted and post-process them to make them look as identical as we could. This was my first time using the plasma cutter, and honestly I didn’t even know it existed until I enrolled in this class, which is kind of embarrassing to admit.
Design Idea and plasma cutting
I chose a beach design for my diamond because it is my favorite place on earth to be (not Galveston tho). I love swimming in the ocean and just spend a good amount of time at the beach overall. So, thanks to Hayden’s recommendations I got to know nounprojects.com, a website where you can get free icons and designs in SVG/AI formats for any type of project. There, I found my design, downloaded it, modified it on Adobe Illustrator so that the island became a separate object from the ocean wave and finally downloaded it as an SVG file for the plasma cutting process.
Angle grinding
Since my two diamonds had so much dross and remaining debris from the cutting process, I proceeded to use the angle grinder machine to smooth everything out. It was a more time-consuming process than I thought, especially given my design with multiple shapes.
Sand blasting
After the angle grinding, I moved onto the sand blasting machine in the wet lab. This was personally my favorite part because I just think the whole concept of sand blasting is so new and cool to me. I was making sure to properly remove all the debris and imperfections from my diamond surfaces, when all of the sudden the pressure of the sand jet dramatically dropped and I could just feel that it was not giving me the same results. After contacting Dr. Wettergreen, we inspected the machine along with some of the TAs, and realized there was an issue with the air compressor of the building, leading to an overall system failure in many of the OEDK machines. So, unfortunately, that day I was only able to sand blast one of my diamonds and had to come back two days later, when the air compressor problem was fixed, to continue my post-processing work. After finally sandblasting my second diamond as well, I ended up with very smooth and nice metal surfaces.
Spray painting
I decided to spray paint my diamond because I had the vision of doing ombré colors in my head. I went ahead and took the blue, orange, and yellow spray paint colors and started painting on the practice metal pieces that were available in the outside part of the OEDK, just to make sure my technique was good. After doing so, I proceeded to start painting my diamonds. I first painted yellow the whole diamond shape, waited for it to partially dry and then added a layer of blue in the lower part, symbolizing the sea. Then, I took the orange color and sprayed in between the yellow and blue layers, to try to create that sunset look I wanted. I have to say it was harder than I expected and I had to make color corrections by painting over and over again as needed. After making sure the color ombré was what I wanted, I added some gloss paint to have a better finish. I first painted one side of the diamond and left the OEDK because I was too tired and I also needed to wait for the paint to completely dry off so I would be able to flip the metal and do the other side. I then came back to the OEDK on Friday afternoon to finish the opposite side of the diamonds and left them to dry over the weekend. Eventually, these were the final results:
Cost analysis
| Cost Category | Cost Type | Cost | Total Price | Source | Quantity | Total |
|---|---|---|---|---|---|---|
| Materials | Aluminum metal | $0 | $0 | OEDK Machine Shop | N/A | $0 |
| Materials | Spray painting colors (blue, orange, yellow) | $3.00 each | $9.00 | Home Depot | 3 | $9.00 |
| Materials | Spray painting (gloss finish) | $5.00 | $5.00 | Home Depot | 1 | $5.00 |
| Labor | Plasma Cutting Operator | $30.00/hr | $30.00 | Steel Supply LP Plasma Cutting Houston | 1 hr | $30.00 |
| Labor | Prototyping Engineer (You!) | $20.00/hr | $20.00 | My rate | 2 hrs | $40.00 |
| Overhead | Facility Cost (Machine Time) | $0 | $0 | OEDK Machine shop | 15 min | $0 |
| Overhead | Quality Control | $12.00/hr | $12.00 | Reddit.com | 1 hr | $12.00 |
| Design | Engineering and Development | $20/hr | $60.00 | Your own rate | 3 hrs | $60.00 |
| GRAND TOTAL | $156.00 |
