1. The History of the CNC Machine
Milling machines have been around since the early 19th century. Driven by the need to
manufacture large numbers of muskets for a young America’s military, the government
funded entrepreneurs, including Eli Whitney – inventor of the cotton gin, to help. In an
iterative manner, these manufacturers developed new technologies to create similar metal
parts for the guns, thus giving birth to the milling machine. These early machines were used
to “rough out” parts, requiring additional hours to smooth out the edges. Though relatively
primitive, these milling machines gave birth to an industry that supports the American
economy.
Early milling machines could only move in two dimensions, which limited their utility. In
1861, just in time for the Civil War, Joseph Brown of Brown & Sharpe invented a universal
milling machine that added a third dimension to the milling process. This machine was very
successful, enabling Brown & Sharpe to build a dominant position in the industry.
After World War One, milling machines were in great demand for creating tool and die for
the nascent automobile industry. Engineers began to find ways to use tracer controls so that
parts could be cut directly from drawings instead of having to create a jig. This idea of
bypassing the manual creation of intermediate pieces would drive the development of more
advanced methods for controlling milling machines.
Towards the end of World War Two and into the early 1950s, engineers started to use
numerical controls on milling machines to create smoother cuts, but such operations
remained very labor-intensive. In 1952, MIT developed a very complex milling machine
that relied on punch tape for numerical input and used 240 vacuum tubes to create smooth
cuts. Such a program was not suitable for production use, but it demonstrated that
numerical control could work for milling. Unfortunately, the labor intensity of it changed
so that now the bulk of the labor time was in programming the punch or magnetic tapes.
Fortunately, the late 1950s and early 1960s saw the advent of the computer, which reduced
the time necessary for such programming. In one instance, use of a computer reduced
programming and milling time from 8 hours to 15 minutes. Soon, companies developed
languages that allowed for easier programming for milling parts and the field of computer

2. aided design (CAD) was born. Improvements in CAD along with the fall in pricing of
computer cycle time meant that it became much easier to design parts in computer
languages that could be easily understood numerically controlled milling machines. As the
microcomputer developed, it became easier to directly feed CAD programs directly into
numerically controlled machines and today’s computer numerically controlled (CNC) mills
were born.
Moore’s Law ensured that the power of microcomputers increased exponentially, while
prices continued to drop. Soon, CNC machines were within reach of small production
shops. Such a shop could purchase a CNC lathe for a few thousand dollars, quickly
recovering the cost and investing in more such machines.
Today, you can purchase a CNC machine online for yourself or your company. Hobbyists
buy CNC machines for use in their garages. Some even build them from inexpensive, spare
parts. If you already own a laptop computer, you can download free CNC software from the
web. For less than $100, a person who is mechanically inclined can build a CNC machine
for his or her own use.
On the commercial side, the principles of CNC are being applied to using other methods of
cutting and machining. For example, laser and plasma cutting use CNC to guide the cuts,
which result in smooth surfaces because lasers and plasma torches melt the cut materials.
On the other hand, if the material being cut is sensitive to high temperatures, a CNC
approach can be used to guide a waterjet cutter. A waterjet uses a stream of very high
pressure water to cut through materials, while taking advantage of the heat dispersing
characteristics of water. CNC machining today applies the basic techniques to a number of
technologies. For more information about milling machine please visit our site:
cncmasters.com.