For this week’s assignment we were to choose a noun of our choice from the noun project and then utilize a CNC mill to cut out our object from a block of wood. My noun of choice for this project was a turtle. However I did not want to cut out a turtle instead I chose to create a turtle themed coaster. Below is the link to the noun turtle that I chose to use. 

https://thenounproject.com/icon/turtle-7187570/ 

Before using the CNC mill to cut out my coaster, I first had to design it. To design my coaster I used Carbide to create a circle initially then I imported my turtle svg, that I downloaded from thenounproject. As having just one turtle on my coaster seemed to leave a lot of empty white space, I chose to add two smaller turtles to the coaster.

An image of my design on Carbide Create.

After finalizing my design, I decided to give toolpaths to my design. For the turtles I gave them a pocket tool path so that the design would just be etched into the coaster. As for the outer circle I gave it a contour tool path so that the CNC would cut all the way through the block of wood and leave me with a circular coaster. Finally I added two tabs to my design so that when the CNC mill is cutting out my coaster it doesn’t fly around after the contour cut is done. Then I loaded my file into Carbide Motion, and following the steps shown during the CNC operating tutorial, I was able to successfully cut out my coaster using the Nomad CNC. The steps that I took to operate Nomad CNC are outlined below in a brief manner:

1. Connect Carbide Motion to the Nomad CNC 
2. Secure my block of wood and a piece of waste plywood to the Nomad
3. Probe the CNC drill to set my zero point 
4. Started my cut on the Nomad

An image of the secured block of wood within the Nomad.

An image of the probing process.

Images of the Nomad cutting out my coaster.

The total cut time for my piece was about 18 minutes. After taking out my pieces I cleaned up the inside of the Nomad CNC and took my piece for post processing. My piece still had tabs that I had to sand out and there were also some rough parts of the wood that I wanted to smoothen out. So to begin the sanding process, I started out with 80 grit sandpaper and then moved to a 400 grit sandpaper. After sanding I decided to finish my coaster with golden oak wood finish. I applied two coats. For this project we had to create two deliverables so I repeated my steps after designing my coaster for a second time. 

An image of one of my coasters pre-sanding with one of the tabs partially on it.

Image of sanding with the 80 grit sand paper. In this image the tab has already been sanded off.

Second round of sanding with the 400 grit sandpaper.

First coat application of the golden oak wood finish, this image is taken before the access was wiped off and the coasters were set to dry.

The coasters after their first coat, followed by some additional sanding, as the finish highlighted some of my previous sanding strokes.  

Based on the cost model below, which accounts for both coasters, this entire project cost $309. A majority of the cost stems from labor costs and facility costs. Overall I am happy with the way my project turned out however, I did notice that some internal walls that I left on my turtle, especially near where the flippers are almost touching the body of the turtle did break off. They probably broke off as the walls were too thin and they probably broke due to stress when the CNC was pocket cutting near them or during the sanding process they couldn’t bear the weight. To counteract this next time, I would try to leave the walls a bit thicker if I wanted them there or use a smaller bit as the bit I used this time was the ⅛” bit, however using a smaller bit would lead to increased CNC milling time. 

Cost Type	Cost	Price	Source	Quantity	Total
Materials	Lumber for wood blocks	$1.52	https://www.homedepot.com/	1	$1.53
	SandPaper 80 grit	$8.88	https://www.homedepot.com/	1	$8.88
	Sandpaper 400 grit	$6.98	https://www.homedepot.com/	1	$6.98
	Wood Finish	$34.99	https://www.amazon.com/	1	$34.99
Labor	Prototyping Engineer (You!)	$36.48/hr	https://www.ziprecruiter.com/	4/hr	$145.92
Overhead	Facility Cost (Machine Time)	$50/month	https://apps.txrxlabs.org/join-us/	1	$50.00
Design	Engineering and Development	$60.70/hr	https://www.talent.com/	1	$60.70

TOTAL: $309

Below are final images of my coasters and my cleaned working space. 

My final pieces.

My cleaned Nomad space.