What is G-code?
G-code is nothing more than motion commands that the CNC machine’s controller interprets to move the toolhead. Of course, those commands are passed on to the motor as the number of turns the motors‘ shafts have to make in one direction or the other. In addition to motion commands, there are commands to start and stop the spindle motor. All these commands are generated when software running on a computer interprets a design as a series of movements. There are many applications like this available, some free and others that can be purchased. Some design applications are also capable of generating G-code (for example, Fusion 360), which can then be passed on to the sender application, which in turn passes it on to the CNC controller. Some sender applications also generate G-code, such as LightBurn (for lasers), Mach 3, and Easel. For the purposes of our projects, we will focus on freely available firmware and sender software.
A note on laser machines
...