It’s time to switch materials! So far we’ve gone from textiles to wood and now we’re dealing with metal!
Traditionally this part is done with the plasma cutter for ENGI 210, but due to it being out of order, we opted for the waterjet cutter instead. Another new technology I haven’t used before for prototyping.
The process for using the ProtoMAX waterjet cutter was pretty straightforward, the problems me and other classmates were encountering with this project is getting the software not to crash or miss the connection with the machine; turning a 20 minute process into an hours long session of troubleshooting and trying again.
To start I grabbed a very thin piece of aluminum scrap and tested how true to size the cut would be when compared to my design, and to my surprise it was basically the same down to the fraction of the millimeters. After this I plugged in the silhouette of my design into the software and arranged 2 pieces on it.
Arranged Design
The saddest part after 2 failed attempts of the software losing connection, is that after the first successful cut of the 2 pieces; the water drain filter was so filled with plastic pieces and scum that, even though it was set at the correct height, the water level rose and pushed one of my pieces down the side of the aluminum block and threw it to the bottom of the machine.
The surviving piece
So then I had to cut a third piece to serve as my second diamond, which was faster since I didn’t get an error this time.
The third piece after being cut
After cutting my pieces, I went looking for the angle grinder, as the instructions suggested using it to take the edge off of the cuts. After asking the Lab Assistants, I was instructed to go to Joe for the tool, who after taking a look at my pieces said that it would be a waste to use an angle grinder on the aluminum as it would take large chunks off of the edges. He instructed me to use a metal file and sandpaper to brush the aluminum and how to do so, and I really liked how it ended up looking.
Brushed and filed pieces
To finish my piece I wanted to do a vinyl mask before powder coating to reveal pieces of the brushed aluminum below. I drew a design of a quick fox doodle that I did in my college notebooks whenever I was bored and cut the vinyl mask easily enough.
Vinyl mask
Powder coating was a struggle, from needing a Lab Assistant or other authorized user to open the wet-lab for us to get the powder coating equipment, to using the equipment by myself, to finding a way to hold the pieces without interior holes. I managed to do it, only to be met with vinyl masks that would be impossible to remove when cold, and that would melt when hot making the removal of them shoddy. By after multiple attempts, and removing the masks followed by using new ones and powder coating again, I decided that I put enough effort into the project already and should leave it as is. For the next time I encounter myself using vinyl masks while powder coating I want to ask my classmates who did it successfully how they achieved it and any tips they have for me.
Final pieces
| Cost | Price | Amount | Source | Quantity | Unit | TOTAL |
| 12″x12″ .16″ thick 2024 aluminum | $81.21 | 1 | OnlineMetals.com | 0.532 | sqr ft. | $43.20 |
| Powder coating | $57.99 | 6 | Eastwood.com | 1 | colors | $9.67 |
| Waterjet cutter operator | $18.00 | per hour | Ziprecruiter.com | 3 | hours | $54.00 |
| Prototype/Designer/Development (Metalworker) |
$20.00 | per hour | Ziprecruiter.com | 2 | hours | $40.00 |
| Facility & tooling cost | $250.00 | per month | txrx.org | 5 | hours | $1.74 |
| Waterjet cutter time | $30.00 | per hour | omax.com | 3 | hours | $90.00 |
| Quality Control | $18.00 | per hour | Ziprecruiter.com | 1 | hours | $18.00 |
| NET TOTAL | $256.60 |
