For our final project, we decided to make chess pieces out of the Empire State Building. We first looked through Thingiverse to find a piece that interested us and decided to go with this piece. For our first gate we 3D printed it how it was but after meeting with Dr. Wettergreen, we decided to modify the size of the piece so it would be easier to mold and so it was closer to the actual shape of a chess piece. We changed the size of our base to be 30 x 22 x 80 mm. 

For our second gate, we followed the steps provided by the teaching team to create a 3D printed piece of the Empire State Building positive mold. This was then used to create the silicone mold in class where we used 4 pieces of cardboard to create an indeterminate box and then poured silicone to create the mold. After waiting a few hours, we took apart the box and were left with our mold. 

For our third gate, we created the other half of our positive mold with the CNC software. After creating our VCarve file, we realized that the estimated time that it would take for the CNC Machine to cut this out would be 7+ hours. After discussing with the teaching team, we decided that this would be way too long and that instead we could use a 3D printed positive mold for the other half. Figure 3 shows a screenshot of the VCarve file. 

After 3D printing our other half of the positive mold, we were ready to replicate the same process in class and create our second half of the silicone negative mold. 

After creating our second negative mold, we combined the two pieces with a few rubber bands and were ready to start pouring polyurethane to cast our chess pieces. This process involved mixing a two part quick set resin while adding food coloring, and then letting it set in the mold for 10 minutes while it cured. We did this multiple times until we reached 8 acceptable chess pieces.

Post processing the chess pieces involved sanding the bottom face and the line in between to create more polished pieces. We then added a layer of clear coat to protect and revitalize the sanded pieces.

We ran into multiple issues during this project. It started with the Shapeoko XXL CNC milling machine not being operational, which meant that we had to abandon the CNC portion of the project since exclusively using an ⅛” bit to carve out the mold was not feasible. Additionally, casting the chess pieces turned out to be quite the challenge, with many pieces having issues such as large air bubbles, over/under pouring and inconsistencies in color, and needed to be recast.

Additionally, it was important to maintain a clean workspace, especially with such a hands-on project that had the potential to leave a large mess behind. Therefore, it was essential to utilize the mise en place techniques and keep on top of our cleaning duties.

Finally, we have included a cost breakdown below as a reference:

Item	Quantity	Estimated Cost ($)
Silicone Mixture	1/10 Bottle	13.10
Polyurethane Mixture	1/10 Bottle	5.80
PLA Filament	1/2 Spool	8.00
Spray Paint	1 Can	13.97
Clear Coat	1/10 Can	0.50
Sandpaper (Variety)	4 sheets	2.50
3D Printer	6 hr @ $135/month	1.10
CNC Machining	6 hr @ $1968/month	16.40
Labor	15 hr @ $15/hr	225
	Total Costs:	286.37