CNC stands for Computer Numerical Controlled. CNC Milling is simply milling that is controlled by a computer. The similarities to regular milling are:

• Block of solid material is bolted to a table*. The table and the block can translate on the xy axis.
• A spinning drill bit [spindle*] cuts material from the block to form the part

The differences are:

• CNC milling machine is controlled by a computer and follows a path
• Regular milling machine is controlled by a human operator
• The precision of a CNC machine can be as high as .0001 inch.
• CNC milling is much faster than a human can do
• A CNC part can be replicated perfectly many times

Programming a CNC Mill

• A part starts out as a design in a CAD[computer aided design] program such as Solidworks or Pro/Engineer.
• Using CAM [computer aided manufacturing] software the design is represented as a series of paths for a cutting bit to follow.
• The output from the CAM program is loaded into the CNC Mill [MCU*] and the part can be made.

*see picture