This week, we were tasked with selecting a file to generate a 3D cutout using the CNC machine. I selected the outline of a stormtrooper from the Noun Project. This blog documents the journey of producing these two pieces, including all the failures and successes. 

To start with, I selected my file from the recommended website, and there were plenty of choices to choose from. However, in the end, I decided on a stormtrooper design, and I elected to cut out the border of the image, creating two cuts with distinct depths. The eyes and other features are to a depth of 0.15 inches, while the other features are to a depth of 0.075 inches. 

After setting up the file, I was able to attend the TA meeting and learn how to use the CNC machine, as well as the correct procedures and guidelines for setting up a successful print. I decided to use the Nomad out of preference and ease of use. I started by clamping/securing my piece of wood, initialized the machine numerous times, and changed out the drill bit to a 1/8-inch bit. Then, I let the machine run. The first run took approximately six minutes; however, as it was nearing the end of the process, I realized that the bit didn’t appear to cut through all the wood. After removing the wood, not only was the piece still adhered to the rest of the wood (in a sizable amount), but the cut was also incomplete, as was the mouth feature illustrated in the file.

After reviewing the file, I first didn’t set the depth of the cut for the outline of the shape to “Stock Bottom”; as a result, the machine was able to cut all the way through the wood. As for the missing feature, it was due to the size of the feature itself. The toolpath that the machine registered for the mouth was too small for the 1/8″ drill bit, and thus, for this part of the toolpath, I swapped the needed bit from 1/8in to 1/16in. Once I remedied these issues, I completed another run, and it was successful. Once I figured out the setup and the file was correct, I finished the remaining part. 

Now that I have completed the CNC machining aspect of the project, I have moved on to post-processing. Since I selected a stormtrooper, it was only right that my final product resembled a movie-accurate stormtrooper. So I began to file and sand both pieces (moving from low to high grit) to ensure that the object was smooth and that the spray paint was able to adhere to the object. It was challenging to remove the debris and rough lining from inside the cuts, which resulted in some visible discrepancies in both objects. Additionally, when attempting to sand and file both objects, I realized that the pieces of wood I had selected were not ideal and already contained markings, stains, and other imperfections. But I continued and decided to apply my first layer of white spray paint. I let this dry and returned to see if it needed another coat, which it did. As a result, I sanded some of the patchy parts and reapplied the spray paint, resulting in a far better appearance than the first coat.

After the second coat dried, I decided to use the resin to fill in the holes on both objects. I selected the pigment “Agate” and followed the correct procedure by measuring out the resin to the desired amount and mixing in the pigment. It was challenging to fill the holes with precision, but I managed to do it while minimizing any unnecessary residue. Once I covered everything I wanted to with resin, I just let it settle and dry. Once all was said and done, I was finished! 

Cost Analysis~

Labor:

Labor: $36.25

5 hours (At Texas minimum wage) = $36.25

Equipment: $1.62

Maker Space (One-month membership, includes all the tools and machines used to construct this project) = $50 per month, $1.62 for a day

Materials: $14.88

Resin: 1 ounce @ $0.28 per fluid ounce = $0.28

Wood: 2 pieces @ $4.06 per piece = $8.13

Spray Paint =$6.47

Total = $52.75

For the things I wished I had done, include selecting better pieces of wood, and also to further process both before and after using the CNC, for example, I should’ve planed both pieces thoroughly and sanded more rigorously so that the spray paint would adhere far better while also minimizing any of the obvious defects within the objects. 

P.S. The final result was not what I had originally intended, but I do not know why. There are red marks on the sides and the top face of one of the pieces.