This week, we learned about the devices to cut metal and the post processing of it. I’ve never had to cut or process metal before, so this was a very interesting learning experience for me!
Process:
Firstly, I decided to do a design of a keychain with Calcifer on it since he is one of my favorite Studio Ghibli characters! I imported the sizes of the diamonds from the class file and started tracing a profile of Calcifer in adobe illustrator. I then exported it as an .ai file and emailed it to myself in preparation of the plasma cutting session that we each reserved.
When I went to the plasma cutter tutorial session, I realized that the plasma cutter cannot cut with .ai files, so I quickly converted it to .dxf file with an online converter. Under the supervision of Madison, I followed the instructions on the instruction sheet in importing my converted file, connecting it to the cutting software (Torchmate 4), connected the air compressor and ran the plasma cutter. A problem that we ran into was when we were making path for the design, it displayed a warning of the hole possibly being too small of an object to be cut. I still wanted to try the hole for the keychain, so we tested it and it turned out to work well! The flames of Calcifer also turned out very well! Here are the front and back of my two plates, there was significantly more dross on the back compared to the front, which would mean more angle grinding for the back side.
The next step was angle grinding. After obtaining the angle grinder from the machine shop and making sure that the cardboard was moved to a safe distance outside, I began angle grinding. My first few passes were very hesitant because as someone who is extremely afraid of flames, the flying sparks were very scary to me. However, I quicky learned that it’s not going to harm me in any way and got comfortable with using it. I made sure to not point the direction towards myself or others and keep a 45 degree angle when passing. The results were very smooth, with all the dross being removed and forming smooth surfaces. It is also clearly visible that there is a lot more dross taken off the back side compared to the front. I made sure to put back the piece of cardboard after I was done with everything outside.
After that, I clamped the two plates and used a file to clean up some edges and corners. Even though the angle grinder was able to make surfaces flat, it was hard to reach the inner corners or the spiky parts of Calcifer’s flames.
I waited until the weekend to start sandblasting since the air compression system of the OEDK building wasn’t working properly on Thursday. I came during a TA session for access to the room and made sure to turn on the exhaust and properly lock the lid after putting the pieces inside.
Sandblasting is my favorite procedure of this project because of the even and clean finish while also being very straight forward to use. Here are the post-sandblasting looks of the plates:
After this, I went back to adobe illustrator and drew a few more details on the file for the spray painting process. I used the Vinyl cutter to create stickers that would help me frame areas during spray paint. I followed instructions on the instruction sheet and transferred the cut stickers using the roll of transfer paper under the table.
Moving on to the spray painting, I took my time and did many different layers for the different colors of the design. I made sure to check the can for the drying time for touch (tends to be 20 minutes) and waited until one layer dried to start the next one.
First two layer of red for front and back:
Putting on the vinyl sticker and doing the middle part of Calcifer:
Putting on the vinyl sticker again for the eyes:
I chose to do the pupil with a sharpie because there wasn’t black or dark grey spray paint:
The matte clear coat twice on both sides:
One thing to point out during spray painting is that even though I used the exact same yellow and orange spray paint, the texture turned out to be significantly different. One had a glossy finish and the other had a gritty texture to it. I’m guessing that one of the spray cans got a little clogged at the beginning and then unclogged and became glossy again, since the one I did second was glossy. It is still very unexpected since I did quite a few test sprays before doing them officially. (left gritty and right glossy)
However, the final results are nice and the gradient is very pretty under both textures! A final picture of them:
Here are some pictures of my cleaned up workspaces:
Cost estimates:
- 1/8″ sheet of steel 13″ x 13″: $12.00 (amazon)
- Spray paint (I used 5 cans and approx. 1/10 of each can): $5.98/can * 5cans *1/10 = $2.99 (walmart)
- Sharpie (pack of 12): $10.40 * 1/12 = $0.87
- Vinyl sticker paper: $9.97 (amazon)
- Transfer paper tape roll: $9.99 (amazon)
- CNC machine usage: $90/hr (practical machinist)
- Manual machine usage: $60/hr (practical machinist)
- Labor as a Design Engineer: $29/hour x 5 hours = $145.00 (zip recruiter)
Total: $330.82
**having all the machinery available would make a great difference
