The Process

The first step of this process was to choose a design to plasma cut, and since I’m such a big fan of apple products, I thought it’d be a fun idea to cut out the Apple logo. I picked a design that I liked from the Noun Project website and uploaded it as an SVG file to Adobe Illustrator. Once in Illustrator, I could correctly size the logo inside the diamond template provided for us.

Once finished dimensioning the logo inside the diamond, I brought the design over to the plasma cutter, following the instructions laid out. I made 4 cuts, doing my best to position my cuts to maximize the number of diamond cuts possible on the sheet to conserve material. 

Once my 4 pieces were cut, I used the angle grinder to remove all the slag left over from the plasma cut. 

Next, I used a metal file downstairs to remove any interior imperfections and slag/imperfections from the edges of the diamond since the angle grinder couldn’t reach those.

Once all significant imperfections had been removed, it was time to sandblast my diamonds. One benefit of the sandblast technique is it creates a uniform look on all sides of the object since the angle grinding had given some parts a lighter silver color, while other parts of the object remained a dark steel shade. In the photo below, you can see the distinction between the sandblasted piece(s) versus the unprocessed one(s):

After sandblasting, I took a break for a couple of days, and when I came back I noticed something very odd about my pieces. Although I had tightly wrapped them in dry paper towels, after just a couple of days, an odd dirt/rust-like color had begun to form on the surfaces:

I felt the need to sandblast the pieces once again to retain the uniform color on my pieces, so photographed above is the piece how I found it (left), and the re-sandblasted piece (right). Once I sandblasted the pieces again, I felt confident in how they looked, so I applied 2 coats of clear coat spray paint to each side of the diamonds.

With this, I finished my design and lastly wrote on the back of each diamond my name and processes.

REFLECTION:

The first part of this assignment was pretty similar to the laser cutting assignment, as with both we started by creating a design in Adobe Illustrator, and then using essentially a CNC to cut out of planar material. The biggest difference between the two projects was the post-processing that was required for the metal-cutting assignment.

I found the angle grinding a little difficult at first, as it took a minute to figure out a good form using the tool. One thing that I noticed was that the angle grinder would remove too much material in some instances, chipping the material on the edges. One way to resolve this would be to be more mindful of where the tool is being applied, so as to not slip and mistakenly take off too much material.

I also found using the metal file was pretty difficult with my apple logo design, specifically, as it was impossible to get inside the small leaf portion of the design, but I was able to use the file on the corners and edges of the piece to clean up any slag the angle grinder wasn’t able to scratch off. I’m still not sure how I would tackle this problem since running sandpaper through the inside of it would be pretty inefficient and potentially also uneven.

Sandblasting was very fun, and it felt very “astronaut-like” to be using the gloves in the vacuum chamber, but it would begin to feel tedious after a while. Especially having to sandblast both sides of 4 pieces, and as I wrote about above, having to do this twice leads to a lot of hand cramps and sweaty time in the woodshop.

If I were to do this process again, I would try to minimize the time between sandblasting and the application of the clear coat, since I’m still not sure what led the rust-like material to accumulate, but I did notice that applying the clear coat prevented it from coming back.

I am happy with my result for this assignment, as I successfully created 2 replicas of the apple logo in the diamond. As I mentioned above, there were some imperfections created along the way, but they were consistent on each piece, especially the defects created by the plasma cutter. So in the end, the two pieces are identical to each other, which is what I set out to achieve.

 

COST ESTIMATE

Raw Materials

• ~18 in^2 steel plate= ~ $2.63 ($21/12″x12″)

Labor

• 6 hours = $45 ($7.50/hour)

Variable Costs (omitting overhead)

• Plasma cutter operation (30 minutes) = ~ $10 (Assuming plasma cutter operation costs $20/hour)
• Angle grinder operation (30 minutes) = ~ $10 (estimate)
• Sandblaster operation (1 hour) = ~ $30 (estimate)

Total Cost = $97.63

This total is spread over the creation of 4 identical diamond pieces, so the price per piece is around $24.4. I think I can decrease the post-processing time/labor cost (and operation cost) by increasing the efficiency at which I angle grind and sandblast, as those took me the longest time. I think that $24.4 for each piece is not a bad starting point, as I think the products came out pretty well, and adhere to the constraint of making two identical pieces.