Computer-numerical-controlled routers can be used to engrave pictures into wood, metal or acrylic plates. This would have been near impossible when CNC interfaces were first introduced, because all coordinates and commands for the CNC had to be written and entered carefully and error-free into the interface one letter or number at a time. Today, computer-aided design programs that can write even the most complex CNC coordinates and commands make this not only possible, but a project that even a novice CNC hobbyist can handle.
Scan the image onto your computer if it is not already in digital format. Import it into your CAD program and give each line of the drawing an engraving depth. This will set the Z-axis of the CNC, while the image itself will give the coordinates for the X- and Y-axis. Note that images should be converted to line art before importing to your CAD program. Simple images will work best for this purpose.
Export the file to your CNC interface. This can be done using a USB drive or simply by dragging and dropping the file onto the CNC if the CAD program and your CNC are linked to the same computer network.
Install a small engraving bit onto the drill head. Make sure that this bit is appropriate for the surface you are engraving on.
Place your substrate under the drill head and turn on the CNC's vacuum to secure it in place.
Start the CNC router and begin the program by pressing the "Start" or green button. Other CNC routers may have other types of buttons to signal this command.
Allow the router to engrave the substrate. It will return to its home position when the engraving is complete. You can then turn off the CNC and the vacuum. Carefully remove the substrate and inspect your engraving.