For this assignment, I applied knowledge learned from class in 3D shapefiles and advanced manufacturing techniques to create two copies of a noun object cut out of wood using a CNC machine.

Firstly, I found the design of a Christmas tree on the website http://thenounproject.com and downloaded the free SVG file. It was created by user Htet Wai Phyo (https://thenounproject.com/icon/christmas-tree-7378553/). To prepare/modify the file, I uploaded it into Carbide Create and setup my workpiece according to the homework instructions. I measured my wood pieces and imputed  the dimensions in the job setup tab (5.435” x 3.43” X 0.575”). Taking the advice of the TAs, I ensured that I accurately measured the wood pieces and imputed the exact numbers due to the sensitivity of the CNC machines.

The first iteration of my CNC cut shape was too large and the contour cut was placed too close to the clamps that secured the wood pieces. I was advised to stop the cut and modify my shape before redoing the cut.

I ensured that my noun object was no larger than 5” on each side. To achieve this, I scaled the shape down to about 4.5” x 3.2” uniformly using the scale feature in Carbide Create. In order to fulfil the home requirement of the contour cut being an outline of the shape, I created a curve vector around the Christmas tree shape to match its shape. After adding tabs to three points of the outline, I proceeded to add my pocket and contour cuts. In order to achieve the shape of the tree, I added pocket cuts with cutting depth 0.125 inches to the inner part of the tree shape vector. I did the same with the tree trunk/base, and the tree platform. I added contour cuts to all the outline vectors, using the stock bottom and top as the cutting depths. Once I saved all the toolpaths, I saved the g-code and proceeded to cut the wood pieces.

Once I imported the g-code into Carbide Motion in the Nomad3 CNC machine, I set up the machine by clamping my wood piece, placing the homing device on the bottom left corner, and probing the machine tool. Once this was complete, I selected “run job” and began cutting the shape. The cut took 25 minutes to complete using the Nomad3 machine. I replicated all the steps above for my second wood piece.

After my cut, I removed the shape from the wood frame by separating the tabs. I cleaned the machine by vacuuming all wood pieces and dust thoroughly. The Nomad3 machine cut produced a lot of roughness and unevenness in the wood. I used 160 grit and 220 grit sandpaper to smooth out the wood and produce even surfaces on the pieces.  I finished my wood pieces by applying a coat of the Golden Oak wood stain and after that dried, a layer of beeswax over it.

The project cost $47 to produce, all costs included. Some waste was generated when I began cutting an excessively large shape on one piece of wood. Looking forward, I have learned to carefully consider the stock size and be very precise with all measurements when working with CNC machines.

Cost Model:

Cost Type	Cost	Price	Source	Quantity	Total
Materials	3/4 in. x 16 in. x 4 ft. Softwood Boards	$15.97 per board	HomeDepot.com	3 3.5” x 5” pieces	$12
Labor	Prototyping Engineer (You!)	$10/hr	Self	1 hour	$10
Overhead	Facility Cost (Machine Time)	$7.50	OEDK Nomad3 CNC machine	2 hr	$15
	Quality Control	$5			$5
Design	Engineering and Development	$5/hr	Self	1 hr	$5
	Iterations	2
Misc.	Waste and Scrap	One iteration of the shape was too large			$15
Total					$47