The final weekly homework was to create a diamond using the water jet cutter and to post process the part in at least 3 different ways. This was repeated for two total parts. To start, I created my design in Adobe Illustrator. I tried to make a sun appearing over some mountains, with the mountains extending to the edge of the diamond I download from the assignment. As I’ll mention later, the mountains extended too close to the edge.
Next, I went to the water jet cutter. After creating the toolpath file, I setup to cut my part. I used 0.03″ steel. In retrospect, I would have rather used a thicker piece of metal. After making sure everything was good to go, I cut the part.
It cut very well… but my design was not good. The cut went way too close to the edge of the diamond, so I went back into the program and took away the lines that got close to the edge. After cutting two more, revised parts, I moved onto post processing.
I filed the edges of each diamond and then sanded them with 200 grit sandpaper. I wanted to try to remove the burr from inside each cut, but that was very difficult. Instead, I flat sanded each part on both sides. While it made the part smooth and safe to touch, it pushed the burrs into the holes, effectively making the lines on the design smaller. I wasn’t too disappointed in the appearance.
Finally, I brought the part to the sandblaster. I taped off the sky and sun on both sides and then taped the part to a block of wood. The mountains got a nice clean finish after sand blasting. I really liked the effect of the uneven finish on the sky compared to the clean looking mountains.
Overall, I spent around one hour designing and cutting the diamonds and another hour post-processing. With my wage at minimum wage ($7.25/hour) as an amateur craftsman, the labor costs are $14.50. A piece of sheet metal big enough for this project can be found on Amazon for $6.26. Water jet cutters cost between $20 and $40 an hour to run, so I estimate a cost of $15 for the cuts I completed. I estimate the cost of sand blasting to be $10 ($40 to $60 an hour). Therefore, I estimate the total cost to be $45.76.
