Day 1

Yet another project that intimidated me… I’m not going to lie and say that the thought of using the angle grinder on my own wasn’t scary at first. I wanted to forget about my intimidation and focus my attention elsewhere and so I decided that I would gift one of the pieces of this project if I was satisfied with it. The idea of gifting someone one of my plasma cut pieces made me try harder to produce a better product.

Before coming into my plasma cutting session on Tuesday (9/27), I decided on my shape. I was gifting this item to one of my coworkers that also works in Electrophysiology so I thought it would be cool to incorporate a heart shape with a lightning bolt– people who work in EP are typically called the “electricians” — hence the lightning bolt. This was my initial idea (from thenounproject).

Once I got to the plasma cutter, it took my partner and I the entire time to get used to using the machine. The longest step was probably jogging the laser cutting to a home position in order to optimize spacing between each cut. We had a sheet of metal that had been used by previous groups so real-estate was short. We were able to each practice a cut on it which helped us decide if our cuts were going to be produced the way we wanted them to and get us familiarized with the plasma cutter. Thank goodness we did a practice run because the shape I got in the end wasn’t what I wanted…

Day 2

I signed up for an additional session on Wednesday with the plasma cutter and came prepared with a new file. I chose a heart shape with an EKG in the middle. The idea was to have the plasma cutter cut out the shape of the heart and leave the EKG. I consulted a lab tech before I got started and asked them for advice on how to achieve this look. They told me that they were a bit hesitant because of how finicky detailed lines can be produced from the plasma cutter but encouraged me to try anyway and see how it goes.

After practicing on Tuesday, I was a lot quicker when using the plasma cutter. I uploaded my file, set my feed rate to 80, jogged to my home, did a dry run, then cut my pieces. The jogging portion definitely took me the most time so I ended up cutting only 3 pieces in order to give my session partner a chance to cut their pieces. To my surprise, the shape actually looked really good! You can definitely tell that the lines inside the heart was an EKG– even the lab tech was thoroughly impressed.

Day 3

After cutting my shapes and feeling pretty darn good about it, it was time for post-processing. Little did I know that a major problem that I would run into was the amount of slag that was left on all of my pieces… I angled grinded for about 45 minutes on all of my pieces and didn’t see much progress in reducing the slag so I went to Mr. Joe for some advice. I thought maybe I wasn’t angling the grinder properly or applying the right amount of pressure. One look at my slag and Mr. Joe told me that it was more than usual and that it would probably take me all day to remove the slag! He asked if I had I cut my pieces yesterday and told me that the air pressure was low then and it prevented the metal from being blown away. He told me I should re-cut the pieces but by this time the plasma cutter’s software was also down… I decided to continue post-processing in the mean time just in case I wouldn’t be able to recut.

Asma showed me a heavy-duty angle grinder that might be able to help to remove more the slag and it did! The heavy-duty angle grinder was able to remove a good bit of slag off my edges but because it was so bulky it was hard for me to remove the slag in the finer areas of the heart and EKG shape. After grinding, I went downstairs to file my pieces. I used a high grit sandpaper (220) to smooth the edges and a rasp to get the insides of the heart. After filing came sand-blasting, which was the step I looked forward to the most. At this point, I decided that I would only focus on the the front side of my pieces and that I would laser cut a piece of wood to attach to the backside.

This was because I didn’t want the slag on the backside to be exposed and have a more aesthetic final product in the end. After sand-blasting the front face, I applied a coat of Clear Gloss protectant and waited 30 minutes for the coating to dry. In the meantime, I laser cutted my wood backs and etched my process on one of the pieces. All that was left to do was hot-glue the wood backs to my metal pieces and I was done! Here is the final result. I’m proud of my product even though there were some setbacks, I learned a lot and glad I accomplished something I could gift.

Cost analysis

Material
Steel sheet: 3 x 14.5 sq in. pc @14.48 (24 x 36″) = $0.73
Wood sheet: 3 x 14.5 sq in. pc @$18.99 (1/4x24x48″) = $0.72
Clear Gloss: 0.25 oz @$4.99 (12 oz) = $0.31

Labor
Labor: 5.5 hrs @7.25/hr = $39.88
Machine Use: 2 hrs @$20/hr = $40.00
Overhead:  2 hrs @$15/hr = $30.00

Total = $111.64