Introduction

I’ve been exposed to CNC machining before but in a very limited capacity. My dad owns a wood and glass manufacturing business and he uses a glass-cutting CNC machine to cut all of his large pieces of glass. The process was very straightforward– we entered the dimensions of our glass piece, entered the dimensions of our final pieces, and pressed enter for the machine to produce the glass pieces.

When going through the modules, I learned a lot of what goes on within each step of using the CNC machine. I was impressed that such a sophisticated program could be used to produce a variety of products for hobbyists to professionals!

process

After completing all of the online learning modules for using the CNC machine, I attended an in-person training session with the Nomad 3 CNC machine located on the first floor of the OEDK. Even though the steps were straightforward, I was surprised at how many steps there were to setting up the machine. Because it was my first time using a CNC, I chose to pursue the beginner level assignment. I used The Noun Project to find an image and decided to go back to my lightning heart idea from the Plasma Cutting project– there was an image I really wanted to cut on the Plasma Cutter but would not be possible due to the plasma being unable to preserve material that its cut. With the CNC machine, I would set the depth that I wanted the machine to cut so I could save certain components of the image. The image I chose was a heart with a lightning bolt in the middle. I wanted to make a paperweight that I could use and also gift.

After uploading my .svg file onto the Carbide Create program, I followed the instructions from my in-person training and used the printed instructions as a checklist to ensure that I did all the steps correctly. I used the BitZero to properly zero the router. Ricky was a part of my in-person training group and was working nearby so I was thankful to run by the steps with him as I was working on the machine.

When setting my tool paths, I decided to contour the heart shape and make a pocket in the space between the heart and the lightning bolt so that the bolt could stand out from inside the heart. Choosing the bit was where things got a little confusing. I remembered to choose a downward probe so the machine could produce clean lines when cutting into the wood, but I chose a ball-end bit initially. After my first cut, I realized that the ball-end bit created dramatic grooves within my pocket which did look very cool, but wasn’t what I intended. Thankfully, Austin was there and suggested that I switch to a square-end bit so I could produce a cleaner pocket for my second cut and it worked! Each cut took roughly 30 minutes and honestly I couldn’t take my eyes off the the bit drilling into the wood. It was so mesmerizing… like cutting into really soft butter (haha!).

Once each piece was done, I was vacuumed the wood shavings and carefully removed the pieces from the bed. When it came to post processing, I wanted the finish to show the natural wood color and texture. I sanded the pieces with sandpaper to ensure the finish was nice and smooth. I also used a triangular shaped rasp to get into the inner fold of the heart.

Alas, I was done! I’m honestly surprised at how well the shapes turned out and I can’t wait to give these as gifts!

cost analysis

Material
Wood: 1 pc 3.5×5.5″ wood + 1 pc 3.5×6.875″ wood @$29.99 (3/4x24x48″) = $1.13

Labor
Labor: 3 hrs @$7.25/hr = $21.75
Machine Use: 2 hrs @$20/hr = $40.00
Overhead: 1 hr @$15/hr = $15.00

Total = $77.88