Board To Be Wild

In this project, I will be making a cutting board. It won't be any regular cutting board, as I will be using the laser cutter to add an engraving into a piece of wood I am given and then filling this with colored resin. My engraving will be a map of Lake Norman and its coordinates, so when I fill it the lake will be colored and defined. I also will add a thumb hole with the CNC machine and then use the router to round the edges. I am planning on giving this cutting board to my grandfather who live on Lake Norman for his 80th birthday. 

Preparing My Wood Pieces

First, before adding any designs, I have to get my wood piece ready. I first used the planer to sand the faces of my cutting board. I then used the woodworking jointer to sand the long sides of the board. I am sharing my piece of wood with a partner and he used the table to cut the piece in half before using the CNC machine or the laser cutter. 

CNC Machine Work

I will be adding a thumb hole to my board with the CNC machine, also known as a Shopbot. We will be using the Aspire software to make the file for the Shopbot. Here is the workflow that I used to make my Aspire file:

• save file in Correl draw as a PDF

• Go to aspire

• Open your PDF file - click “open existing file”

• Change the page size

• Go to toolpaths and select the “profile tool path” option

• Select the hole to add the toolpath

• Change the tool to “End mill (1/2”)”

• Select “calculate” to see the toolpath run

• Save the file to EngProj

• Download file onto computer connected to Shopbot

• Add NITTO tape to bottom of board(which is now cut in half)

• Find new dimensions of board

• Raise machine with the command, "JZ, 3"

• Move machine to home with the command, "J2, 0,0"

• Move machine to "J2, 16, 4.5" and then have it tap the plate

• Re-home

• Run a test cut in the air by selecting file and selecting "Offset Cut"

• Run your cut by selecting file and then "No Offset"

Laser-Cut Deep Engraving

For my lake design and the coordinates, 35.5020° N and 80.9180° W, I will be using the laser cutter to make a deep engraving for the resin. I started off by making a design of my cutting board. I added my Lake Norman map image with the background removed and I made a bitmap of this image. I added a circle to see where I would end up putting my hole. I used the text feature to write the coordinates and then I changed the text and size to get it to look how I wanted. I then deleted the circle I made because I will not be using the laser cutter to add the hole. I saved this design as an SVG. I tested this file on a piece of cardboard before running the real thing, simply to see how my design looked. I had to use the CNC machine first, but then I went ahead and deep engraved my design. I ran it multiple time to get the depth I wanted. Here is the workflow I used for deep-engraving:

• Create file of design

• Save file to EngProj

• Upload to computer connected to laser cutter

• Add wood to laser cutter

• Place design on the screen

• Change material settings to wood and deep engrave

• Send the job and focus the laser

• Run the job as many times as needed to get the depth needed

Resin and Final Touches

Once I had my wood prepared with the thumb hole and my design engraved, I painted my design with a coat of resin. This would act as my base. I then poured water in my design to find out how much resin I would need to fill it later on. It was held by my coat of resign I had added. I then added a hot glue wall to contain my resin after pouring it. I wanted to make my resin look marbled, so I chose two different blues, one lighter and one darker, and I split the amount of resin I needed in half to find out how much of each color I needed. I split this number in half to find out how much of each part, part A and part B, I needed per color. I mixed these two very well before pouring each color in different places getting the marble effect. My teacher used the propane torch to get all of the air bubbles out of my resin. I let that dry over the weekend and when I came back I used the drum sander to smooth the extra resin off, leaving the wood with the lake and the coordinates. I wet my board to have the grain rise and let that dry over night. I used the orbital sander to sand this off. I then used the belt sander to round the edges of my board to my liking. I oiled my board and let it dry over night. When I checked on it, it felt a little hairy so I used a piece of 400 sand paper and oil sanded it. My board is now done and I can give it to my grandfather for his birthday. 

Problems I Faced

One problem that I faced while using the CNC machine was while the machine was running. As it moved to start cutting the hole, it added a line right outside of the hole. It turns out that while setting it up, we had based the height off of the jig and not off of the table as we should have. Because if this, it started drilling where it thought there would be just air, when in reality my board was there. I fixed this by making a paste with wood glue and wood shavings and filling in the dent. 

The next problem I faced occurred after I had poured my resin and I had wetted my board. When I came back the next day, my cutting board had warped very badly. I ended up fixing this warp with many different steps. I wetted my board again and clamped it to the table with a piece of wood of top, trying to correct some of this warp. I then ran it through the drum sander to even out the taller edges. It helped a lot and I continued sanding my board to prepare it for oil.