In this project, we were tasked with preparing a file to be cut using a CNC machine. I started by finding a SVG vector file of a compass from the Noun Project. I imported this file into Carbide Create, scaled the shape appropriately, and generated toolpaths that describe how the piece will be cut. I used two pocket paths and one contour path around the perimeter of the piece. This results in three different cutting depths, as the arrow is cut down halfway between the top of the piece and the lower pocket.
During the CNC tutorial period, I retrieved my file and prepared to cut. I measured the wood and put its dimensions into Carbide Create and rescaled the compass shape appropriately. Before I started the cut, I was told the contour toolpath should be last in the sequence so that the piece isn’t loose while the pocket toolpaths are completed. I also ran into an issue where the pocket toolpath over the arrow shape left failed to reach the edges of the arrow shape, as shown below. After much troubleshooting we were unable to fix the issue, so I simply sanded these areas once the cut was complete.
Once the first cut was complete, I realized the contour toolpath had not cut all the way through the piece. I’m still unsure of why this happened, as I rechecked the dimensions and they had been entered correctly. Regardless, I was able to push the piece through, breaking it away from the rest of the wood. This partially damaged the outer portion of the piece, but I was able to sand most of this damage away smoothly. For the second cut I carefully measured and entered the dimensions of the wood, and the contour toolpath cut all the way through.
In terms of aesthetics, I planned to spray paint the arrow red and the rest of the compass silver. To accomplish this, I taped over different areas of the piece to keep the areas separate. After the fact, I realized I hadn’t taped perfectly so there were some flaws in the paint job, but overall I’m satisfied with how the compass turned out.
Cost Analysis:
- Machine Use: $30 per hour * 2 hours = $60
- Spray Paint: 2 colors * $6 per can = $12
- Wood: $0.50 per foot * 5 inches = $0.21
- Labor: $20 per hour * 4 hours = $80
Total: $152.21
Clean Workspace
