Hello!
This week I familiarized myself with the water jet cutting machine and began incorporating some past post processing techniques to improve the final appearance of my final metal project.
Water Jet Cutting
To start, I imported a koala vector file into the adobe illustrator diamond template provided in class. Following the water jet machine setup instructions, I measured the thickness of the aluminium sheet of metal I was using, adjusted the water jet machine’s “head” relative to the aluminium metal, and set the home position for the cutting path. Before starting, I conducted a full speed dry run to make sure it was following the desired path and would still be on the piece of metal.
During my first attempt, the water jet only engraved my entire design, both the koala and the diamond outline, instead of cutting through the metal as intended. To troubleshoot, I readjusted the water jet machine’s head, remeasured the thickness of the aluminum, and added more sand to its respective container; however, this resulted in the same issue and I decided to talk with a TA.
She recommended increasing the aluminum thickness (which I changed to 0.11”), and also made sure the height of the machine head was appropriate. After making these adjustments and completing the proper setup, I began the machining process again and was able to successfully cut two identical diamond pieces with my koalas.
Filing
For post processing, I began by filing the edges of the diamond pieces, as they were still fairly sharp after cutting. I filed each side at a slight slant to create a more smoother, polished finish that was aesthetically pleasing. I repeated this process on all edges for both diamond pieces.
Sand Blasting
Since I planned to powder coat the metal, I decided to sand blast it first to remove any surface imperfections and create a smooth, even texture. This was my first time sandblasting, and it was incredibly satisfying to watch the surface texture change.
Spray Coating
When the air compressor for the powder coating stopped working, I decided to use a clear spray paint as my final post processing technique. To ensure an even coat, I hung my piece on the drying rack using paper clips and placed a cardboard barrier surring my metal pieces before lightly spraying. After applying one coat, I let it dry for 20-30 minutes, completing my final product shown below; I used a napkin to wipe away some of the dripping spray paint since the aluminum didn’t absorb the spray paint as quickly as wood, which I practiced in this class earlier.
Reflection
Looking back, this project required a lot of troubleshooting, particularly with the water jet machine. However, I appreciated how precise and quick the machine was, especially when handling some of the sharp curves in my design. In the future, I would like to try powder coating to achieve a more refined finish on metal. That said, I’m glad that my attempts at troubleshooting the water jet worked and now I feel more comfortable with using the water jet machine.
Cost Analysis
| Material | Amount | Cost |
| 12 in. x 24 in. Plain Aluminum Sheet in Silver | (⅓ of a sheet) x $14.63 / Sheet | $4.88 |
| Water Jet Usage/Worker | $21/hr x 1 hour | $21 |
| Sand Blaster Usage/Worker | $18/hr x (⅙ hours) | $3 |
| Filing | 1 | $9.97 |
| Spray Paint Coating (Clear) | 1 | $5.98 |
Clean Up
