I was perusing the available list of icons on The Noun Project when I ran into an icon of Totoro from the Studio Ghibli movie “Spirited Away.” It was so adorable that I knew I had to CNC cut it for this homework. I started by preparing the file on Carbide Create, following the posted tutorial. There was a lot of design freedom in terms of where to make pockets, so I played around with the simulation tool and ultimately decided to proceed with this design:
To cut out my pieces, I used the Shapeoko Pro. I began by securing my wood using double-sided tape and a few clamps, making sure to place a piece of sacrificial wood underneath. Next, I set the zero for the machine using the BitZero tool.
Finally, I was ready to upload my file and start the cut.
While my first cut was successful, my second piece had some complications. Due to the accumulation of sawdust during the cut, the double-sided tape came a bit loose during the final contour cut, and the piece started to move around. Fortunately, I was able to stop the machine as soon as this occurred, preventing damage to the piece. However, the piece had not been fully cut out. Not wanting to waste material, a lab tech suggested using the bandsaw to cut out the remaining contour, so I proceeded with that instead. With that, I had my two Totoros!
Clean workspace after CNC cutting.
To post-process my pieces, I began by sanding. I used a dremel tool with a rougher bit to sand down some of the wood I was unable to reach with the bandsaw, and I followed that by using a narrow, smoother bit to clean up some of the imperfections in the cuts created by the CNC. Next, I sanded the entire piece at 120, 180, 280, and 320 grit by hand to smooth out the surfaces and prime them for painting.
Clean workspace after sanding.
I debated whether or not I should use resin to fill in some pockets on the pieces, as we didn’t have resin dye in the colors that I envisioned for Totoro. However, I decided that using resin would be a good learning experience, so I went ahead with it anyways. I mixed up my resin and added one small drop of black dye (hoping to create a grey color), then began to carefully add the dropwise into a few pockets dropwise.
I noticed that the pockets on one of my pieces was more shallow than the other, as the same amount of resin would spill out of one but not the other. I guessed that this might have occurred because the CNC was cutting air for my second piece when it first began, resulting in shallower pockets. However, I wasn’t too concerned about the resin stains because I planned to paint over the surfaces anyways. Following Totoro’s canonical appearance, I painted my pieces with acrylic paint and let them dry overnight. With that, I had my final pieces!
Throughout this homework, I encountered quite a few trials and tribulations, and there are definitely things I would do differently next time. Notably, I would try a different clamping configuration on the CNC cutter instead of using double sided tape, as that would be much more reliable and resistant to sawdust accumulation. Also, I probably wouldn’t use resin on my piece, as I’m not sure if I really like the aesthetic outcome of it. In spite of those challenges, I am overall pretty happy with how the pieces turned out!
Cost Breakdown:
Materials:
- 0.75” x 3.5” x 5.5” blocks of wood (2) = $7.18
- assorted sandpaper = $8.98
- epoxy resin (1 oz) = $0.94
- acrylic paint = $12.79
- popsicle sticks = negligible cost
- 2 artist paintbrushes = $0.42
Labor:
- 6 hours at $12/hr (average Rice student worker wage) = $72
Equipment:
- Makerspace access for $50/month = $4.83 for 3 days
- includes CNC cutter and affiliated tools/software, bandsaw
Total Cost: $107.14
