This week’s assignment in ENGI 210 was to personalize a diamond shape using Adobe Illustrator, cut the diamond out of aluminum using the plasma cutter, and post-process the piece to our liking.
To prepare for my plasma cutting tutorial with Dr. Wettergreen, I finalized my diamond design early in the week. I opted for a simple two-gear offset design to fit the technical design theme of ENGI 210 and the OEDK as a whole. I created a single gear using the star and circle tools, join the shapes, cut them appropriately, copied and pasted the design, and reflected it across the vertical axis in order to produce the image below.
Next, with the supervision of Dr. Wettergreen, I followed the proper protocol and steps to successfully cut this shape out of aluminum using the plasma cutter. The plasma cut path was a bit wider than my original design. However, I still liked the look of the cut, so I decided to go with it.
I cut four identical diamonds so that I could test a variety of different post processes before committing to one route. The first order of business was to remove the dross protruding from the under side of the diamonds. I first used the rotating wire brush on two of my diamonds. I decided to give the angle grinder a try hoping for smoother, cleaner results. My wishes came true! The angle grinder definitely creates smoother edges than the wire brush. I even decided to grind down the sides of the diamond for a nice visual gradient and textural feel. 
After angle grinding two diamonds, I still had two wire-brushed diamonds to test various post processes on. I wanted to experiment as much as possible with these diamonds to instill confidence and accuracy when post processing my final diamonds. I first dabbled with the sandblaster. I then tried polishing the sandblasted diamond, which I decided I did not like the effect of. I also spray painted one side of the sandblasted diamond and one side of the unfinished diamond. I did not love the look of either and decided that I wanted my finalized diamonds to be simply sandblasted.
half sandblasted, half polished test diamond
My final step was hands-down the most difficult. I decided to fiber etch the steps for this project onto my diamond. I loaded the etched diamond document onto the laser cutter computer. I first cut the diamond shape out of wood. I left the wood in place and popped the test diamond into the cut out so I knew it would be in perfect position to be etched. I then calibrated the machine to the proper fiber etching settings to initially etch a spray painted side of a spare diamond. I was very happy with my results.
Test etch in wooden cut out
The photo above is a bit blurry, but the etch came out centered and clear. I then used the sandblasted side to test different rastor settings that would show through just the sand blast. After finalizing my settings I was ready to etch my pristinely angle grinded and sandblasted diamonds. 
Again, it is not perfectly depicted in the image, but the etch came out great. It is not the deepest or most noticeable etch, but I like that effect. It does not take away from the sleek, industrial theme of the diamond, but rather acts a discrete detail. I managed to deliver a polished product without painting the piece, and for that, I am proud.
Cost Breakdown:
The amount of metal I used for test and final iterations of the geared diamond fit within the dimensions of a 10$ sheet of aluminum.
I probably spent six hours total on this project from creating the Adobe Illustrator file to etching with the fiber laser. Again, because this is more of a hobby for me than an assignment or job, I would only charge 5$ an hour.
I also used a number of complex machines and tools, including the plasma cutter, angle grinder, sandblaster, and laser cutter. Industry average for overhead, consisting of machine rentals and utilities, tools, adhesives, etc., is 15% of the finalized materials and labor pricing.
Therefore, the total cost of the process is 46$. Only two of my diamonds would be presentable to sell, so I would list each at 23$.
I had limited experience working with metal prior to the project. I now feel much more equipped to tackle a variety of two dimensional metal working projects, and I look forward to incorporating metal into my midterm machine!
