What Kinds of CNC Machines

What Kinds of CNC Machines Exist? The short answer is more than we could possibly go into here, but let's try to cover some of the major categories of CNC, which are the most common.

CNC is the acronym for Computer Numerical Control. It is an outgrowth of the older term "NC", which stands for just "Numerical Control". It refers to the idea of controlling machine tools programmatically via computer. With the older "NC" term, a computer need not be involved. The machine might be controlled using, for example, punched tape.

NC, and later CNC, allowed for tremendous increases in productivity for machine tools because the machines could be run automatically without requiring constant attention from their operator. Before the advent of such automation, there was a lesser automation opportunity in the form of hydraulic tracer systems. Such systems used hydraulics to cause the cutting tools of a lathe or mill to follow a template. The taper attachments available for many manual lathes are not unlike the hydraulic tracer capability, it's just that the tracer is capable of more elaborate templates than simple tapers.

But the advent of first NC and then later CNC radically increased the amount of automation that was possible.

CNC Machine Lathes

Some view Lathes as the only universal machine tool because a lathe can make all of the parts needed for another lathe. A lathe spins the workpiece in a spindle while a fixed cutting tool approaches the workpiece to slice chips off of it. Because of this geometry, lathes are ideal for parts that have symmetry around some axis that could be chucked up in the spindle.

CNC Lathes have at the very least the ability to drive the cutting tool under g-code control over 2 axes, referred to as X and Z. They may have a considerable amount of other functionality as well, and there are many variations on lathes such as Swiss Lathes.

The act of cutting a workpiece on a lathe is called "Turning".

CNC Milling Machines

In a mill, the cutter is placed in the spindle where it rotates. The workpiece then moves past the cutter so that chips may be sliced off. The act of cutting a workpiece on a mill is called "Milling".

CNC Mills have at the very least the ability to drive cut in 3 dimensions (some older machines may be limited to 2 or 2 1/2 if there are limitations on when that 3rd dimension may be used) which are referred to as the X, Y, and Z axes.

CNC Routers

A CNC Router is actually a type of CNC Mill, typically one that uses what's called a "gantry" configuration. Typically they're called CNC Routers instead of CNC Gantry Mills when they're used to cut wood, but this need not exclusively be the case.

Many think of CNC machines as being focused on cutting metal, but there is a huge market for CNC woodworking machines of which the CNC Router is the principle example.

There are many more types of CNC machine than just these three most common types including CNC presses of various kinds and so on.