Overview
For this assignment, we had to create identical metal diamonds using the plasma cutter and various post-processing techniques we’ve learned so far in class. Elena and I wanted to do a musical theme, so she recreated Weezer’s iconic blue album, and I recreated Charli xcx’s BRAT.
Plasma Cutting
I originally wanted to cut out the letters that spelled out “brat” on the diamond, but I realized that would also cause the center of the “B” and “A” to fall out. I could have chosen a different font, like the ones that have the vertical lines between letters to make it possible, but I valued accuracy over complexity. I also was not confident in the plasma cutter’s ability to get the small cuts successfully, so I just cut out plain diamonds. As we all know, there were a lot of issues with the plasma cutter, so while I was able to get my first diamond cut during the tutorial, I had to wait quite a while before I was able to cut the others. I ended up with a total of 4 diamonds so I could test out different approaches without messing up my final products.
Plasma cutter actually working.
Post-Processing
After plasma cutting, I started off with using the angle grinder to remove the dross. After going over each corner until smooth, I lightly brushed over the surface to remove spots of rust.
Grindin’ that.
Removing some rust on the surface.
Setup on the magnetic apparatus to angle grind three diamonds at once.
Once I was done with the grinder cart, I took my diamonds to the sandblaster to smooth out the surface to allow paint to stick. Even after using the angle grinder, there was still a thick layer of oxidation that I needed to remove, so I was standing at the sandblaster for a while.
Two diamonds, one after angle grinding alone, and the other after sandblasting. Note the lighter and matte surface.
Diamonds, so sandblasted.
I came back another day to cut out my vinyl stencils. I created a .svg file with the correct diamond size and the same font as the album, then imported it to the vinyl cutting software. Using transfer tape, I separated the design into two stencils: one with just the letters “brat,” and the other being the negative of the design.
Every vinyl is brat.
Cleared vinyl cutter space.
The next day, I decided to start spray painting. I wanted the shade of green to be as close to the album cover as possible, so I just decided to order some, but I did have to wait for it to arrive. I started by spray painting the backs just to make sure the green was brat enough. It was.
I might spray something stupid.
Sufficiently bratty green diamonds.
On my first test diamond, I applied the “brat” letter vinyl stencil directly to the metal, then applied the primer and green on top. This left behind a bare metal “brat” on the diamond that I then attempted to align the negative stencil on top of and then spray paint black. This turned out to be very difficult, and the test piece I did this with ended up showing some of the bare metal on the surface due to misalignment of the stencil. The vinyl also pulled off some of the green paint.
If you zoom in, you can see some bare metal showing next to the black letters.
On my second test, I went straight to using the negative stencil, then applied the black spray paint. This left behind a much cleaner looking “brat,” but the letters were slightly raised, even after applying a clear coat.
Negative stencil over lightly sanded green base.
Diamond with no bare metal showing near the letters.
On my final diamonds, I spray painted the entire top surface green. Then, on top of the green, I placed the “brat” letters and sprayed a few coats of matte clear coat. The next day, I removed the letters, then applied the negative stencil and spray painted it black. Using a matte clear coat and allowing it to dry completely prevented sticking and left behind a sunken layer for the black spray paint. The totally green background also meant that slight misalignment wouldn’t be very visible, creating a more seamless look.
Final Delivery
I finished my diamonds by printing out the steps I took to create the diamond. I wanted the steps to look like an album track list, and I printed it in arial narrow font of course. I superglued the slips of paper to the back of my diamonds and placed them on the 555 table. I forgot to take a photo because I had to rush to the airport (“Apple” reference) the next morning.
Clear spray paint table.
Cost Model
| Cost Type | Cost | Price | Source | Quantity | Total |
| Materials | Steel Sheet (¼x20x20”) | $20.00 /sheet | Amazon | 1 Sheet | $20.00 |
| Black Vinyl (12×48”) | $6.99 /roll | Michael’s | 1 Roll | $6.99 | |
| Primer | $5.98 /can | Home Depot | 1 Can | $5.98 | |
| Green Spray Paint | $28.74 /6 cans | Amazon | 1 Can | $4.79 | |
| Black Spray Paint | $5.98 /can | Home Depot | 1 Can | $5.98 | |
| Clear Coat | $5.98 /can | Home Depot | 1 Can | $5.98 | |
| Labor | Plasma Cutting Operator | $15 /hr | ZipRecruiter | 1 Hour | $15.00 |
| Sandblaster Operator | $18 /hr | ZipRecruiter | 1 Hour | $18.00 | |
| Vinyl Cutting Operator | $16 /hr | ZipRecruiter | 1 Hour | $16.00 | |
| Spray Painter | $21 /hr | ZipRecruiter | 3 Hours | $63.00 | |
| Prototyping Engineer | $36 /hr | ZipRecruiter | ½ Hour | $18.00 | |
| Overhead | Machine Shop Access | $40 /month | The Maker Barn | 1 Month | $40.00 |
| Total | $219.72 |
For this cost model, I reduced the prototyping engineer’s work hours to only half an hour. That’s because the metal itself as the plain diamonds from the canvas, and “brat” logo is so simple that I only needed to take the diamond shape and put a text box in the middle. This didn’t actually take me more than 5 minutes, but I decided to count the half hour anyways. I did not consider any copyright implications or royalties in the case of possible monetization of this product, since the album is so iconic and widespread. However, I am not Charli xcx, and do not claim an
