Preparing My File

For the CNC Machining assignment, I began by importing a picture of a butterfly from the Noun Project into Easel. I then resized the image and drew a 3″ diameter circle around it. I experimented a little bit with the depth of cut I would like for my butterfly and eventually decided on 0.05″ since I did not want the cut to be too deep.

Cutting My Piece

Once my file had been prepared, I went to the woodshop to begin the process of operating the CNC machine. For the most part, the process was pretty straight forward. Easel was a very intuitive software to use and had many of the steps that I needed to go through to set up the machine outlined in an easy to follow format from measuring my wood to manually zeroing the z-axis.

The only difficulty I had with the machine set up was finding and changing the bit. I could unfortunately only find 5 or so bits on the table, so I just changed the bit I had initially planned to use on Easel to one that I found in the woodshop to make my job easier. In the end, I ended up using the “solid carbide upcut 3 flute spiral” bit.

For my first cut, I managed to miscalculate where the xy zero should be set and part of my design ended up being cut outside of my piece of wood. I fortunately was able to correct this before cutting my two final pieces.

Post-Processing

Once the pieces were cut, they had a few rough edges that I wanted to smooth out through sanding. I used three different grits, beginning with 120 then using 220 before finishing with 320, to leave a smooth finish on the surface of my pieces and prepare them for painting.

To add color to my design, I used a black wood stain on my CNCed blocks. I then went back in with green paint to color in the lines of the butterfly. Finally, I mixed white spray paint with green paint to cover the body and wing of the butterfly. This was all then covered with layers of matte spray paint to maintain the longevity of the piece.

In Hindsight

Aside from my aforementioned mistake miscalculating the xy home, I would have also liked to spend more time experimenting with different bits and cut depths. Though I am happy with my final pieces, I feel it would have been a bit more rewarding to produce a more complex product. Admittedly, my peers who did try to complete more complicated designs (or even those that were not that difficult) did encounter many more obstacles than I did, so I am not sure how much more stressful my process would have been.

Cost Analysis

• 2 ft of unfinished pine – $1.86
• 1 can of black wood stain – $10.98
• 1 tube (4.1 oz) of green paint – $2.99
• 1 can of white spray paint – $4.98
• 1 can of matte spray paint – $4.98
• assume that access to machinery and software is negligible (for instance, it is a communal resource)
• labor : 3 hours * $20/hour = $60

TOTAL = $85.79