Hello!         

Continuing my animal theme, I chose to CNC sea turtles for this project. It was my first time using the CNC machine, and it quickly became my favorite tool to work with.

I selected a sea turtle design from Thingiverse and used Carbide Create to adjust it to fit a 3.5″ x 5″ piece of wood. I modified the file to create pockets for all internal parts of the turtle, including its scales and other fine details.

Initially, I used the default ⅛” end mill, but it was too large to capture the finer elements of the design. After some trial and error, I switched to a 1/16″ bit for all the pocket features and set the maximum depth to 0.1″.

Since I wanted a cutout of the sea turtle, I added a contour path using a 0.2″ offset in an outside direction. I ensured there was enough spacing between the pocketed design and the outline, and I added three tabs around the exterior to secure the piece during cutting. For the contour, I set the max depth to 0.766″, with tab height and width at 0.1″.

Before starting the actual cut, I ran both toolpaths through the simulation to check the final product. When I first probed the Nomad CNC machine, I encountered an issue where the 1/16″ bit didn’t make contact with the wood. After remeasuring and correctly setting the tool path, the pocket cut worked properly and took about 13 minutes.

Next, I switched to the ⅛” bit for the contour cut, which took another 11 minutes. I used the bandsaw to carefully remove the tabs and separate the turtle from the wood block.

After repeating the process for another turtle, I moved on to sanding. While the backside sanded smoothly with a hand sander, I underestimated its power on the front side and accidentally chipped some delicate parts near the turtle’s head. I finished the rest by hand sanding the rough corners to avoid further damage.

For a natural finish, I applied Danish oil and let the turtles sit overnight. To protect the inner pocket areas of the sea turtle, I filled them with a clear resin coating, which also added a glossy touch to the final look. The resin was simple to use, with a 1:1 mixing ratio.

Overall, I really enjoyed the CNC process. The machine was intuitive and fun to work with, and I’m excited to use it again for our upcoming chess piece!

Cost Analysis 

Material	Cost
Resin	24.13
Danish Oil	13.99
2 wood planks (3.5” x 5”)	$3
Sandpaper	$0.42
3 hours of labor ($12.75/hr)	$38.25
Total	$79.79

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