For the Plasma Cutter assignment, I wanted to make a 3D piece so I decided to make a 3D version of the Rice Owl logo (Figure 1). I image-traced the logo on Adobe Illustrator and cut the image so only the wings would be cut by the plasma cutter. 

Figure 1. Preview of Finished Laser-Cut Piece

After laser cutting the piece, there was significant slag on all the cut edges (Figure 2). To remove this, I first used a dremel with a metal-sanding bit. This process did work, but was extremely slow and took a lot of manual effort. I decided to try the angle grinder. This machine proved to be much more efficient. It was difficult to get the slag off the wing edges because they were interior edges. However, after switching between the front and back and using different angles, it was sufficiently flat as shown in Figure 2.

Figure 2. (Top) Diamonds with Slag after Plasma Cut
(Bottom) Diamond Before and After Angle Grinder

To finish it off, I used sandpaper to remove the slag on the stubborn edges. Next, I used the sand blaster to remove the grinding strokes from the surface (Figure 3). 

Figure 3. Sand-Blasted Diamond

Then, I bent up the edges of the wings with pliers, a wedge, and clamps. Lastly, I spray-painted the front navy blue and the back silver (Figure 4).  

Figure 4. Finished Diamond Piece

This part took me 4 hours. At $12 an hour labor costs would be $48. To estimate machine cost, I used rates from TXRX lab in Houston. Membership to the machines is $50 per month. I can estimate that I would use the machine 10 hours a month, each hour would cost $5. I used the laser cutter and angle grinder for 2 hours total. So, machine costs would be $10. The raw materials would be a 8”X 8” of a sheet of metal costing $1 and a small fraction of a can of spray paint with estimated cost of $0.50. Total material costs are $1.50. The total cost for this piece is $59.50.