Engraving wooden cutting boards with Dremel CNC
Recently, I introduced a policy to use separate cutting boards for different food types in my kitchen. I bought several bamboo cutting boards and found myself in need of a way to mark them. The marking should communicate the purpose of the board, such as: meat, bread and cheese, vegetables, and so on. The best way, I thought, was to engrave them using a CNC machine.
Luckily, I had access to a Dremel CNC micro milling machine with a Proxxon FBS 240/E drill attached. Some time ago, I had used this machine to mill a hole for a Webasto timer in my car. So, it made sense to use it again.
I did it successfully and collected the info here on how to do it and what software to use.
To use a CNC, we need to generate G-code files first. My requirements were basic. The program had to generate uppercase text shapes, each letter about 15 mm high and made of constant-width lines. Some of the letters include Polish diacritics. I didn’t want V-carving, since it requires much more fiddling to achieve satisfactory results. Surprisingly, I had to test several G-code generating programs before I stumbled upon the one that worked for me: F-Engrave.
I bought several 3.175 mm V-shaped carving cutters and fiddled with various parameters of the text generator in F-Engrave. An old cutting board nearing the end of its life was my test subject. Note that bamboo is quite hard, and the Dremel CNC is more or less just a toy, so I kept the speed values low. After some tweaking, here are the parameters:
| Parameter: | Value: | Comment: |
|---|---|---|
| Milling bit | V-BIT 3.175 mm, 45° 0.2 mm | |
| Spindle speed | 20 000 RPM | Maximum speed on the Proxxon drill. |
| Feed rate | 40 mm/min | |
| Plunge rate | 20 mm/min | |
| Engrave depth | 1.2 mm | |
| Font | romans2.cxf | Bundled with F-Engrave. |
The screenshot below illustrates the final settings for the G-code generation. F-Engrave bundles a collection of fonts; romans2.cxf looked best to me. Note, the engraving depth is a negative number in this program!
To generate a Grbl file that loads into CNCjs without fuss, you need to set the value of G Code Header to empty, as shown below:
Loading the G-code file into CNCjs is straightforward. The result is quite satisfactory.
