This week’s assignment in our workshop course presented an exciting challenge that blended precision engineering with personal expression. Our task? To create two identical pieces from a provided piece of wood measuring 3.5″x5.5″x0.75″ using a CNC machine. The project not only tested our technical skills but also our ability to infuse creativity into a functional item.
Choosing the Design
The first step was deciding what to carve. After some contemplation and searching for inspiration, I chose to craft a coaster featuring the Fireball Liquor label—a personal favorite of mine.
Preparing the Design
To bring this idea to life, I first had to prepare the design in a digital format. I used Inkscape to convert the Fireball label into an SVG file, which could then be uploaded to Carbide Create—the software that would allow me to set up the toolpaths for the CNC machine. Adjusting the design to accommodate the tooling limitations, such as the 1/8″ bit unable to handle intricate letter cuts, was part of this process. The ability to edit directly in Carbide Create was very useful, allowing me to tweak the design until the simulation displayed exactly what I envisioned.
Machining the Coasters
With the design set, it was time to start cutting. I decided to use both a larger and a smaller CNC machine to compare for efficiency. The larger machine, running on older software, required some adjustments to the file, while the newer software on the smaller machine streamlined the process significantly.
Our teaching assistant, Madison, helped monitor the machines with me to ensure everything went smoothly. Interestingly, the smaller machine required occasional pauses to vacuum up sawdust—a step not needed for the larger machine thanks to its built-in vacuum system. One issue I encountered was that the smaller machine did not cut through the wood completely, requiring some manual finishing with sanding to free the coaster without damaging it. Additionally, I noticed that the smaller machine also didn’t cut as deep for the pockets of the coaster. To make my coasters as identical as possible, I sanded down the front face until pocket depths looked similar in both coasters.
Post-Processing and Finishing
Once cut, the coasters needed finishing touches. I initially considered staining them red to match the Fireball theme but opted against it due to the intricate details in the pockets which could make even application difficult. Instead, I chose to highlight the natural beauty of the wood, applying two coats of clear varnish to protect and enhance the coasters, with sufficient drying time between each coat.
Clean Up
I also made sure to clean up any areas that I used for this assignment. This included cleaning up the sawdust around the CNC machines, the sawdust created from sanding down the coasters, and returning clear coat back to its correct location near the loading dock.
Reflection and Learning
The completion of these coasters not only provided a practical item I could enjoy but also offered valuable insights into working with different types of CNC machines. The hands-on experience highlighted the importance of adaptability and attention to detail in woodworking. Each coaster, a representation of personalized craftsmanship, now serves not only as a functional drink accessory but also as a reminder of the skills and creativity involved in their creation.
Overall, this project was a rewarding integration of technical precision and personal expression, resulting in a set of coasters that I will cherish and use with pride.
| Cost Type | Cost | Price | Source | Quantity | Total |
| Materials | Wood (Pine) | $ 7.97/8ft | Homedepot.com | 1 in | $ 1.00 |
| Matte Clear Coat | $ 5.98/can | Homedepot.com | 1/10 | $ 0.60 | |
| 120 grit sand paper | $ 14.98/pack | Homedepot.com | 1/15 | $ 1.00 | |
| 280 grit sand paper | $ 6.98/pack | Homedepot.com | 1/4 | $ 1.75 | |
| Labor | Woodworking Operator | $ 18.00/hr | Ziprecruiter.com | ½ hr | $ 9.00 |
| Prototyping Engineer (You!) | $ 15.00/hr | Personal Charge | ½ hr | $ 7.50 | |
| Overhead | Facility Cost (Machine Time) | $ 80.00/hr | Practicalmachinist.com | ½ hr | $ 40.00 |
| Quality Control | $ 24.00/hr | Ziprecruiter.com | ½ hr | $ 12.00 | |
| Design | Engineering and Development | $ 45.00/hr | Zippia.com | 10 min | $ 7.50 |
| Iterations | 1 | – | – | – |
Cost for BOTH Coasters: $ 59.35
Cost for SINGLE Coaster: $ 29.68
This project was streamlined and efficient, focusing primarily on CNC machining with minimal reliance on additional materials. The financial outlay for this task considered several elements, including materials, labor, engineering and development, and notably, machine time. Access to CNC machines can be somewhat restricted to the general public, making machine time rental a significant cost driver in our analysis.
On a larger scale, while the cost of renting CNC machines may seem manageable, maintaining high quality becomes a crucial concern. CNC machines require meticulous maintenance—regular bit replacements and careful setup to avoid damage to the machine’s base. These factors ensure the ongoing precision and performance of the equipment, which are essential for producing high-quality outcomes in any large-scale manufacturing endeavor.
