CNC (computer numerically controlled) machines are electro-mechanical devices. CNC machining is one of two ways that engineers, machines or makers can generate a physical part from a computer design file. CNC machining is a subtractive process, where the material is removed from a stack. CNC machines were developed in the 1940s and 1950s, with punched tape technic. The code to control the machines would be manually punched to a data card and fed into a system that would then interpret the data. These early machines were elementary and their functionality was limited. CNC machining technologies rapidly grew as technological capability accelerated in the late 20th century.

Machining is a way to transform a stack piece of material such as aluminum, steel or titanium into a finished product or part. CNC machining relies on digital instructions specifically referred to as G-code. Before modern computer-aided manufacturing and computer-aided design, programs such as Autodesk fusion 360 machiners manually write a G-code to control these machines. However, CAM programs today allow you to a 3D model and automatically generate G-code that would drive the machine with little input. CNC machines run faster at higher precision and accuracy while simultaneously allowing the transformation of the digital design into a physical part.

 

Conventional machining technologies:

1. Drills work by spinning a drill bit and moving a bit into contact with a stationary stack.

2. Lathes function in reverse to drilling. Lathes spin a block of material against a stationary drill bit or cutter to remove material in a circular or fluid path. The shape capabilities are more limited than other technics. Modern technology allow the creation of things such as square holes or non-circular shapes.

3. Milling machines involve the use of rotary cutting tools to remove material from a stack piece. These machines function similar to drills with the tooling capability encompassing much more variety.