Introduction
For the CNC Machining assignment in ENGI 210, I chose to create an elemental tile that represents the four classical elements being Water, Air, Earth, and Fire. The basic idea came from the base design from the noun project. However, given the limitations we had in size of our wooden square and an opportunity for some creative freedom, I modified the svg so that the toolpaths and depths creation process would be smoother. I completed this project at the Intermediate level, which required using at least two different milling depths and cutting out the shape. The machining was completed using the Nomad 883 Pro and the process was executed by creating the tool path and depths in Carbide Create and running the cut on Carbide Motion.
The Process
Design
I began by selecting the elemental icons from The Noun Project, editing them in Carbide Create to modify the original earth and air symbols. Each symbol was slightly modified for clarity and compatibility with the size of the toolkit that we were required to use for this project. I then made further modifications to correctly scale the design to fit the 3.5″ by 3.5″ wood blocks and place the design in the lower left half. Once this was completed I created the pocket toolpaths for the symbols themselves and contour toolpaths to define the outer boundary and frame the grid. My three heights were at 0.250″ for the inner block cuts, 0.500″ for the outer block cuts, and .750″ for the outside grid cut. 4 tabs around the corners were also added to prevent from dislodging during the cut.
Creating and modifying the toolpaths were a difficult part of the process for me as the size of the tool bit relative to the size of our wooden block created some cut limitations. This was very apparent in my initial choice, an svg of the bay bridge, where the lines of the svg scaled onto our wooden block were too small to cut with the 1/8″ bit. Because of this I pivoted to the elemental tiles design and still had some struggled with that, but I was able to get through them with the modifications I mentioned earlier.
Initial Bay Bridge svg on left and Bay Bridge CNC cut on right
Toolpath Setup
Initial Elemental Tile SVG
Modified Elemental Tile SVG for 1/8 Toolkit
First Attempt Toolpaths
Toolpath Simulation
Fabrication
Once toolpaths were finalized, I exported the g-code from Carbide Create to Carbide Motion and set up the Nomad 883 Pro. These are the steps I took to prepare the wooden block for the cut.
- Loaded the g-code from carbide motion
- I secured the wood stock into the clamp
- I used double sided tape to connect the zeroing sensor to the wood at its bottom left corner
- I initialized the machine.
- I zeroed the machine at the bottom left corner
- Removed the sensor once zeroed
- Closed the protective door and started the cut.
The cutting went smoothly, with all pocket and contour paths executing correctly, taking 15 minutes to complete. I did have to watch for the bottom of the outer block near the end of the cut since it was 0.750 and came close to touching the bottom of the clamp. Afterwards, I immediately used a vacuum to remove the large amounts of wooden dust that has accumulated in the CNC and block during the cut. I then repeated this process with a second wooden block to get the same result.
First Elemental Tile attempt (Toolpath needed to be edited to avoid top right lower wall)
Wooden blocks after CNC cut
Once I had cleaned up the CNC and logged out, I use a wooden bandsaw to cut the remaining section of the wooden block from the tiles for a cleaner look. I also sanded both with an orbital sander on the outside and file for the smaller crevices to remove outward wooden bits and smoothen the feel. When this was completed I selected a dark wooden stain and applied it to both blocks, painting every section of each. I then cleaned up the area, put away the stain, and washed the paint brush.
Two elemental tiles after cutting, sanding, and filing
Two blocks right after dark wood stain was applied
Clean Workspace photo
Final Product
The finished elemental tiles turned out pretty nicely with clearly defined elemental symbols at varied depths with clean lines and rich dark and clean look thanks to the post processing and stain. I successfully made two identical tiles to display my knowledge of the process.
Finished Product
Reflection
This assignment helped me to better understand how vector based design translates into toolpaths, and how pocket vs contour cuts interact during fabrication. If I were to do it again, I’d experiment with different bit sizes or even use V-carve to create a finer detail cut (Like a geography cut, I saw others in the class do). Overall, the process of preparing tool paths, setting up the machine, and troubleshooting steps gave me the hands on experience to become more comfortable with using a CNC.
Materials Used
Wood Blocks (3.5” x 3.5” x 0.75″)
4 blocks ($8.00 at $2.00 each)
Dark Wood Stain
Shared use ($3.00)
Labor (Design, Setup, Machining, Post-Processing)
1 hour ($7.50 at $7.50/hour)
Machine Time (Nomad 883 Pro CNC)
15 min ($3.75 at $15.00/hour)
Total
$22.25
