CNC Computer Numerical Control machines are widely
used in manufacturing industry. Traditional machines such as vertical
millers, centre lathes, shaping machines, routers etc.... operated by a
trained engineer have, in many cases, been replaced by computer control
1. CNC machines can be used
continuously 24 hours a day, 365 days a year and only need to be
switched off for occasional maintenance.
2. CNC machines are programmed with
a design which can then be manufactured hundreds or even thousands of
times. Each manufactured product will be exactly the same.
3. Less skilled/trained people can
operate CNCs unlike manual lathes / milling machines etc.. which need
4. CNC machines can be updated by
improving the software used to drive the machines
5. Training in the use of CNCs is
available through the use of ‘virtual software’. This is software that
allows the operator to practice using the CNC machine on the screen of a
computer. The software is similar to a computer game.
6. CNC machines can be programmed by
advanced design software such as Pro/DESKTOP®, enabling the manufacture of
products that cannot be made by manual machines, even those used by
skilled designers / engineers.
7. Modern design software allows the
designer to simulate the manufacture of his/her idea. There is no need
to make a prototype or a model. This saves time and money.
8. One person can supervise many CNC
machines as once they are programmed they can usually be left to work by
themselves. Sometimes only the cutting tools need replacing
9. A skilled engineer can make the
same component many times. However, if each component is carefully
studied, each one will vary slightly. A CNC machine will manufacture
each component as an exact match.
1. CNC machines are more expensive
than manually operated machines, although costs are slowly coming down.
2. The CNC machine operator only
needs basic training and skills, enough to supervise several machines.
In years gone by, engineers needed years of training to operate centre
lathes, milling machines and other manually operated machines. This
means many of the old skills are been lost.
3. Less workers are required to
operate CNC machines compared to manually operated machines. Investment
in CNC machines can lead to unemployment.
4. Many countries no longer teach
pupils / students how to use manually operated lathes / milling machines
etc... Pupils / students no longer develop the detailed skills required
by engineers of the past. These include mathematical and engineering