I began the process by using the given diamond file and finding a P online. I had to convert a file to .ai which I found didn’t let me edit the P when I put it in Illustrator so I traced it and then used that P to make my diamond file. I eventually removed the middle of the P as I realized that piece would fall out anyways when I cut it.
Traced the P to get the shape
I made 3 P diamonds and arranged them close to each other so that I didn’t waste too much material when cutting them out. I chose the speed setting by comparing the thickness of the steel that I would be cutting to the samples in the Machine Shop. In future I would do this more accurately with a caliper to try reduce the dross produced as I had quite a lot but it honestly wasn’t that hard to remove.
The sample I thought the steel matched
Cutting the diamonds
I encountered some issues while doing the plasma cutting. Firstly, it cut the line leading up to the initial cut from the origin instead of starting the cut at the diamond. We fixed this by turning off the plasma cutter setting in the bottom left of the screen on torchmate. Another issue I encountered was an issue with my file where it cut out the diamond first instead of the P but only for one of the diamonds. This meant that it dropped into the water before it had the chance to cut the P. I ended up not having to fix this issue as the other two diamonds were good to use. I also had to turn on the tool on the top left of the screen to plasma otherwise it only cut a part of the project.
Cut diamonds
Diamond before removing the dross
To remove the dross from the diamonds I used an angle grinder until it was all removed.
Diamond after removing the dross
Next, I used the sand blaster to remove all the rusted steel and smoothen it out as much as possible.
Result of sand blasting
To finish it off, I used a clear coat to provide a nice shiny finish.
Clear coat on the diamonds
It was quite humid and a really cold day so I was struggling to get the clear coat to dry and used a heat gun to help with the drying process. Sadly, I rushed it a bit too much and it isn’t a perfectly smooth finish and one of the sides got a little stuck to the cardboard around the edges when I turned it over as you can see a little in the next pictures.
Overall, I learnt a lot during this process and am a lot more confident in my use of the plasma cutter and other tools used.
Final Product
Final Product
Clean space after spray painting…I used cardboard to prevent the clear coat from getting on the table.
Clean table after spray painting
Cost of Production
Materials: The steel cost $93.76 for 2304in^2 (4x4ft) (Metal Depot). I used approximately 48in^2 (8x6in) so $1.95 in steel costs. I used a little polyurethane at $6.19 a can, assuming I used around a tenth of that is $0.62. Total Materials: $2.57
Labor: 4.5hrs at $15/hr is a total of $67.50.
Tool Maintenance and Overheads: Overheads are approximately 15% of total cost so $10.51. (This includes the use of the heat fun, angle grinder, OEDK technicians, OEDK computers).
Cost to Use the Plasma Cutter: Around $15/hr (Xometry) for 1hr is $15.
Total: $95.58
