Hello everyone! In this post, I will describe how I created my Pai Sho tiles using a CNC machine. The White Lotus tile, being one of the most iconic symbols from Avatar: the Last Airbender, was the obvious choice to me for this project. Searching on The Noun Project, I found the following .svg file for the White Lotus tile I used for this assignment.

Creating the Carbide File

After downloading the .svg from The Noun Project, I noticed many parts of the file were not centered and aligned. Each concentric segment of the design was not exactly centered with the center circle, causing extra spacing on certain sides of the piece.

After importing this file into Carbide Create, I manually edited the designs such that they were evenly spaced and perfectly centered. I also added tabs around the outside of the piece so that when I created the contour cut, the piece would not move in the machine and cause damage or mess up. I set the design to be 3″x3″.

Next, I set up the contour and pocket toolpaths. The contour toolpath was used on the outermost circle where the piece would be cut out of the wood. I used a 1/8″ end mill for the contour toolpath. For the rest of the designs, I assigned a pocket toolpath with a depth of 0.125″. Because the scale of the design was small, I used a 1/16″ end mill. With a 1/8″ end mill, I would not get the full details cut out properly since the petals in the design were closer than 1/8″ apart from each other. The final time estimate for the piece came out to 10-12 minutes.

Using the CNC Machine

With the .c2d file completed with proper toolpaths, I was now ready to cut the piece on the CNC machine. I used the Nomad 3 to cut these pieces. Before setting up the machine, I measured the thickness of the wood using calipers to ensure the depth of the contour toolpath was sufficient to cut the piece without cutting into the machine itself. I adjusted the file based on the width of each piece of wood I used and set the contour cut depth accordingly.

After initializing the machine, I clamped the wood into place with a scrap piece below it just in case the contour path cut too deep. I then probed the corner of the piece to zero the machine to the corner of my piece of wood.

Now, I was ready to begin cutting. I inserted the 1/16″ upcut end mill into the machine to complete the initial pocket toolpaths.

All looked well as the machine worked on the pocket cuts. However, after the full cuts were completed, I took the piece out and noticed the pocket toolpaths were rough and had lots of splinters and marks at the bottom.

Dr. Bisesti noted that the reason this likely occurred was that though I used a 1/16″ upcut end mill, it was not a flat end mill. Thus, some of the toolpath carvings could still be seen, and the cuts were not clean.

After selecting a new, flat, 1/16″ upcut end mill, I tried cutting my pieces again. This time, I could tell the designs were a lot cleaner!

Once the pieces were finished, I pushed the piece out the back to pop out the tabs holding it in place. Now, the tiles were ready for post processing.

Post Processing

The first step to cleaning the tiles was to remove the tabs sticking out of the sides. I used a file to remove these.

Next, I lightly sandblasted the pocket cuts to ensure that any rough edges or splinters were completely removed since I would not be able to use sandpaper to easily remove any imperfections. Then, I used 80 grit and 150 grit sandpaper on every side of the tiles.

For the last step, I wanted to have a simple, clean finish to the piece. I did not want to use a stain since it might drastically change the color. Rather, I decided to use beeswax to give a smooth finish while enhancing the natural color of the wood.

Following the instructions on the bottle, I poured beeswax into a cloth and generously applied it to the tiles following the wood grain. After 20 minutes of drying, I used a new, clean cloth to polish the tiles and remove any excess wax. The beeswax was quite simple to apply, and I feel it was finished a lot faster than using spray paint or stains with extra drying time necessary. One issue I ran into was getting the wax into the pocket cuts given how narrow the spaces were. I used a small paintbrush and generously applied the wax before wiping the excess with a cloth to ensure the pocket cuts were covered.

The tiles were now complete. I felt that the richness of the wood was brought out nicely and the pieces had a consistent smooth finish, so I decided not to apply a second coat.

Overall, I felt that the process of designing files and using the CNC machines went smoothly. After adjusting the file to match the size of the piece and choosing the right sizes of bits, I was able to minimize the cut time while retaining maximum resolution. Aside from using the wrong end mill at first, I did not run into any issues with the machine. The CNC machine, like the water jet cutter, provided speed and precision in making these designs, and my tiles turned out great!

Cost Analysis and Cleaned Workspace

Total Cost Estimate: ~$59

• Labor: (4 hours @ $10/hr) = $40
• 0.75″x 3.5″ x 8′ wood = $9
• Feed-N-Wax Wood Polish = $10

The cost analysis is a rough estimate as machine rental costs were not needed since we used the OEDK equipment, and material costs reflect bulk supplies instead of how much material was used for this project.

Below are images of the cleaned final workstations used.