For this project, we would make something using a CNC machine. I wanted to make a landscape using the CNC machine so I began to look through some. I ended up finding an STL file for a mountain that’s in my mother’s hometown, so I chose to cut El Nevado de Toluca. I decided to make a coaster out of the mountain so that it could be functional as well.

I started by modifying the file by scaling it down and trimming it into a circle. To CNC the mountain, I decided to use my brother’s CNC machine because of its clamps which made the cuts more reliable and accurate. I tried creating toolpaths with the provided software of the machine, but I noticed that it took a raster toolpath and wasn’t as clean as I wanted. I did this testing on foam so that I could speed up the process while not hurting the machine.

To try to make better toolpaths, I learned how to use Fusion 360 to make the toolpaths. After tediously learning the software, I was able to create a pocket clearing rough pass and a parallel finishing pass. This was done with a 1/8 in and 1/32 in drill bit respectively. I didn’t like how the parallel pass finished the mountain because the lines were visible. Because of this, I switched to a morphed spiral finishing pass which had much better results. After testing with the foam, I cut the mountain out with wood, adding a contour pass to cut out the disk.

After cutting the mountains, I cut out holes in a piece of plywood that could hold the mountains while I poured epoxy resin in them to create the coaster. From there, I placed a mountain in one of the holes and poured resin over it. I noticed that there were a lot of bubbles in the epoxy and the heat gun would not remove them. After researching further, I realized I mixed the epoxy to quickly and created the bubbles. From there I poured resin on top of two other mountains, to much better results.

After the resin cured, I cut most of the wood around the disks and finished sanding them down until there was only the disk and the resin. After I sanded the disks to the right size, I had two coasters with mountains in them. I really liked the how the coasters came out and the detail that the mountains had.

Cost Breakdown:

Foam Block: $17.99 (Amazon)

2 in. x 4 in. x 8 ft. Piece of Lumber: $5.98 (Home Depot)

8.8 oz. of Epoxy Resin: $16.98 / 4 oz. used: $7.72 (Amazon)

8 hours of CNC Machine Time at $20 per hour: $160 (3Q Machining)

10 hours of labor at $15 per hour: $150

 

Total Cost: $341.69