It’s a shame for a mechanical engineer to not have the experience to work with metal and cut it with a plasma cutter. I decided to plasma cut an iconic Taipei 101 building in my hometown, where I spent the past 19 years growing into the person I am today. The metal diamond design is meant to bring the connection between my hometown, Taipei, and Rice University with the iconic Rice Blue. For post-processing purposes, I used the angle grinder to remove the dross after the plasma cut and the sand blaster to create a clean surface free of rust and surface imperfections. Lastly, I finished with spray painting.

The recipe for my taipei 101 metal diamond in rice blue

1. create vector file in adobe illustrator

I used the diamond template to ensure my diamond’s scale stayed consistent with the requirements. I removed the complicated internal geometry of the Taipei 101 building to avoid impossible cuts, including small geometric shapes and thin lines that were limited by the kerf of the plasma cutter.

2. Prepare the vector file from illustrator in torchmate.edu creation software

I imported the Taipei 101 .ai file I prepared in Adobe Illustrator into Torchmate.EDU creation software. First, I made the path. Second, I created a male tool path. Third, I selected an ARC lead-in with a 0.2″ radius in the Lead In/Out tab. Lastly, I exported the file in .dxf format.

3. launch torchmate 4 to start the cut on the plasma cutter

I imported the .dxf file from Torchmate.EDU creation software to Torchmate 4 to generate the G-Code for movement and torch control. The laser at the torch head was used to identify the spot for plasma cutting. Once the cutting location was identified, I performed a dry run to ensure the cut wouldn’t fall off the edge of the material. Next, I moved on to turn on the plasma cutter arc to cut my long-waited metal diamonds.

After a hiatus of OEDK losing the proper pressure level for compressed air, I regained access to the plasma cutter to complete the missing second metal diamond. After the plasma cut, there was an accumulation of dross on the underside of the cut, which was the residue of the molten metal.

4. First thing first: remove that ugly dross with angle grinder

The grinding part using the angle grinder to remove the dross took longer than I originally expected. However, the hard work paid off in the end, resulting in a smooth touch to the hand.

5. happy sand blasting

Sand blasting was used to create a completely clean surface free of any rust and surface imperfections. It is also a critical step before powder coating to ensure the bonding of the powder coat.

6. last step: finishing, maybe i just called it too early

Originally, I opted for powder coating as my preferred method of surface finish. When I finished almost every step leading to a perfect powder coat, the oven for powder coating failed me for never reaching 400 degrees Fahrenheit and staying at room temperature.

7. resort to spray painting for finish

I used water to wash away the powder on my metal diamond. I sandblasted one more time before starting the spray paint to ensure no contaminants were present on the surface.

I used the RUST-OLEUM 2X UltraCover Paint+Primer to spray paint and cover my diamond with the Rice blue paint. 2 more light coats were applied 3 minutes apart before moving to RUST-OLEUM Matte Clear Coat. I applied 3 layers of light Matte Clear Coat 3 minutes apart. I waited 1 hour before I flipped the diamond on the paper to continue on the blue spray paint and matte clear coat with the same procedures.

8. clean up the workspace

I made sure to put back all the spray paint and clear coat bottles that I used to make my metal diamonds. The cleaniness of the workplace is the collective responsibility of everyone who is using the space as our privilege.

reflection after completion

After completing the plasma-cut metal diamonds, I originally thought the metal-cutting part using the plasma cutter would be the most challenging and time-consuming part, as presented in the assignment instructions with a long list of steps. However, when I had the vector file ready to import into the Torchmate software, the cutting could be finished in less than 15 minutes. The post-processing part, including the use of angle grinder, sand blaster, and spray paint, was, in fact, the most time-consuming part. I really enjoy making my own metal diamonds, paying homage to my hometown’s iconic building, Taipei 101, and my Rice school spirit in blue.

manufacturing cost analysis

The overall cost of manufacturing two identical metal diamonds is $ 252.97. The biggest part of the manufacturing cost came from the plasma cutter labor and facility cost. In sum, we can understand the selection of material in the engineering design is an essential step in striking the balance between cost and performance. In this case, we would need to justify the cost of choosing metal instead of other materials that are cheaper to process.

Cost Type	Cost	Price	Source	Quantity	Total
Materials	16-Gauge Weldable Sheet (12″x12″)	$ 14.98	homedepot.com	10% sheet (14.5 in2)	$ 1.498
	Rust-Oleum Painter’s Touch 2X UltraCover Paint+Primer (Deep Blue)	$ 6.48	homedepot.com	1.67% bottle	$ 0.11
	Rust-Oleum Painter’s Touch 2X UltraCover Matte Clear	$ 6.48	homedepot.com	1.67% bottle	$ 0.11
Labor	Plasma Cutting Operator	$ 19/hr	ZipRecruiter.com	0.5 hr	$ 60
	Prototyping Engineer (You!)	$ 25/hr	Indeed.com (Engineering Intern)	1 hr	$ 25
Overhead	Facility Cost (Machine Time)	$ 260/hr	CNCzone.com (Plasma Cutting Cost)	0.5 hr	$ 130
	Quality Control	$ 22.5/hr	Glassdoor.com (Quality Assurance Inspector)	0.5 hr	$ 11.25
Design	Engineering and Development	$ 25/hr	Indeed.com (Engineering Intern)	1 hr	$ 25

Total Cost: $ 252.97