There are more and more hobbyists building their own CNC machines. In this series I'm going to try to explain the various parts of a CNC machine, how it might relate to the hobbyist trying to build their own, and give examples and pictures where I can. This is going to be a constantly growing article - so check back often for updates and additions!

First off... What does "CNC" even mean?
The letters in "CNC" stand for "computer numerically controlled" - so if you have a CNC Machine, then you have a machine that is computer numerically controlled... Simple enough, right? OK so I understand the computer part, you need a computer - but what's this "numerically controlled" business? Basically what numerically controlled means is that the computer drives the machine using numbers - X, Y, and Z coordinates specifically (and actually sometimes more but that's a topic for later, let's keep it simple for now)

XYZ CoordinatesOh boy, X, Y, and Z coordinates? You remember back in math class when you worked on X and Y coordinates, right? Well if not, basically, THAT world is laid out on a grid of numbers with zero being the very center and the X Axis going east and west and the Y axis going north and south. Going to the east would take your X numbers increasing in the positive, while going to the west would make them decrease going in the negative direction. the same goes for the Y axis, north is positive, and south is negative.

OK, what about this "Z" business? The Z axis represents up and down in our world. with up being positive and down being negative and below the zero.

What does all that mean for CNC? Well that's the basis of it all really! The computer "tells" the machine to go to a certain X, Y and Z position! It's as simple as that! We will get to calibrating a machine and making sure it knows where all the coordinates are, but basically if a computer tells a machine to go to X1.250, or in other words "go 1.250 inches in positive direction of the x axis", then the machine will do just that. How does it do that? you ask? we'll get to that, trust me :)