CNCing an Outline of My Favorite Lake! | ENGI 210: Prototyping and Fabrication

This Week in EDES 210: CNCing an Outline of My Favorite Lake!

This week in EDES 210, I learned the process of using simple CNC machining processes to make multi-plane 3d objects. From learning the process of preparing cuts in CarbideCreate, to calibrating the Nomad 3, I feel prepared to use the CNC cutter in multitudes of future projects.

Choosing my Model

I live in Reno, Nevada, a city which is close to one of the best lakes in the world: Lake Tahoe (not a subjective opinion at all). Tahoe has been one of the core sources of fun in my childhood: in the summer I’ve hiked along it and swam on its beaches. In the winter, I’ve skied alongside it. Tahoe straddles the border of Nevada and California, with both states contributing to its distinctive shape:

I chose an SVG of the outline of Lake Tahoe from the Noun Project, and exported it into carbide create.

I created a 0.15’’ offset of my shape and pocketed the inside of the shape 0.1’’. I chose the smallest values for pocketing that I could without sacrificing the imagined aesthetic of the part. Due to the large pocket, the cut was estimated to take around 30 minutes!

Cutting the Wood

I calibrated the Nomad 3, and then began my cut.

I stopped the cutting halfway through to clean all the woodchips up with a shopvac. My final result looked like this:

Artifacts from the drill and stray wood burrs dotted the piece. I had to push the part through the wood to get it loose, so several splinters were left over. I repeated the cutting process for my other piece, and then was ready for post-processing.

Post Processing

I coated each piece first with 100 grit sandpaper, then 120, then 220, and finally 400. With the lower grit paper, I removed the drill lines and stray burrs. With the 400 grit paper, I smoothed each piece so the final surface has virtually no roughness.

I then applied beeswax to each piece, and let them sit for 20 minutes. I chose beeswax because it preserves the wood’s natural appearance, enhancing its original hues while maintaining its authentic look. After 20 minutes, I wiped the excess beeswax off, and sanded each piece again. I then coated the pieces in a final coat of beeswax, and topped everything off with a clear coat.