Build Your Own Mini CNC Plotter Using Scavenged Parts

Computer numerical control (CNC) is used to automatically control a wide range of machine tools, including mills, lathes, laser cutters, and even 3D printers. Most CNC machines take commands in the form of G-code, which tell the machine something like “move the X axis 2.5 millimeters in the positive direction.” By chaining many, many such commands, you can create complex toolpaths. There are many open-source G-code interpreters out there today, and many of them can run on Arduino-compatible development boards. Tuenhidiy has an Instructables tutorial explaining how to use an Arduino and parts scavenged from an old CD or DVD drive to build a mini CNC plotter.

A CNC plotter is a bit like a printer, except that it draws continuous lines instead of a series of tiny dots like an inkjet printer does. For simple line drawings, CNC plotters tend to be more efficient and create smoother lines — a bit like the difference between a raster image and vector image. This particular CNC plotter is too small to do any real work with, as the plotter area is only about the size of a Post-It note. But, it is an affordable way to become better acquainted with CNC concepts, G-code commands, and the mechanics of automated machine tools.

Control is handled by an Arduino Nano board paired with a CNC Shield V4 and two A4988 stepper motor drivers. Those three components are able to precisely set the position and speed of stepper motors. Those stepper motors can be found in CD or DVD drives, as they were used in those devices to move the optical reader back and forth across the discs. Most of the plotter’s frame can be constructed from the internal brackets from the drives. The pen is pushed down by a stapler spring when it is drawing and then lifted up by a hobby servo motor when it’s making rapid movements between line segments. If you’re looking for a cheap and fun way to experiment with CNC machines, this is a great weekend project to check out.