Overcoming the limitations of the 3 axis machine.

Standard desktop routers and milling machines permit cutting in relief but what if you need to machine a an object like the one illustrated - a container for a new magic potion, with the product name boldly embossed? 

A few machines in the desktop arena offer the possibility of adding a 4th axis, allowing the work piece to be rotated as it is cut. (A device similar to the tailstock of a lathe holds the work.) The crossed arrows indicate the movement options for the cutting tool and it becomes obvious that even adding a 4th axis will not allow us to cut an opening into the neck of the container. Specialised large, industrial machines can incorporate a powered knuckle in the Z axis allowing the spindle to be positioned for undercuts and cavities. These are the so-called "5 axis" machines.

 There is another way ...

You can slice your 3D model in, for example, Autodesk rendering software and machine several pieces before assembling them.

CNC Notes