When CNC was first invented it was a technology that was adapted to fit
existing machines. Today CNC technology is still being retrofitted to
various machine tools but there are also many machines which are created
for the sole purpose of being CNC machines.
Machines that are Retrofitted
Milling Machine
Milling machines are often retrofitted
with CNC technology. This process involves removing all the mechanisms
built into the machine to make it easy for a human to operate, such as:
hand wheels and DRO (Digital Read Out) electronics.
The machine will usually have its old
lead screws replaced with new very high accuracy ball screws and various
new mounts built for mounting the actuators to the machine.
Lathe
Just like the milling machine, lathes are also commonly retrofitted with CNC technology in the exact same way.
Machines that are Custom Built for CNC Operation
Router
CNC Routers are a very common piece of
machinery you will see a lot when learning about CNC. These are machines
built exclusively to be operated by CNC technology and have no human
interface other than through the computer.
Routers are generally for producing
larger work and more commonly built with the idea of cutting wood,
plastics and sheet metal in mind. Router also are most commonly found in
a 3 axis setup (X, Y and Z). This set up will allow cutting of basic
profiles and 3 dimensional relief machining. There are also CNC router
which are 4, 5 or even 6 axis, these machines are more suited towards
cutting more complex shapes or prototype models.
Milling Machine
There are many milling machines today
which were built specifically for CNC as opposed to being retrofitted at
a later stage. Some of these machines can be absolutely massive and
have built in tool changers, auto-feed mechanisms for loading in
material and various electrical sensors for safe monitored cutting.
CNC Plasma Cutter
CNC plasma cutters are very similar to
CNC routers in size and setup, however plasma cutters don’t require as
much of a powerful set up because as opposed to dragging around a
spinning tool in material they fly above the table with a plasma torch.
Plasma cutters are made for cutting 2 dimensional profile shapes into sheet metal.
CNC Laser Cutter
CNC laser cutters follow the same
principle as the plasma cutter. However laser cutters use a much less
destructive force than a plasma torch – A laser. Laser cutters are often
good for cutting wood, plastic and metal. Each will need a different
strength of laser suited for the material.
3D Printer
A 3D printer or 3 Dimensional
printer uses a similar set up as a CNC router or laser cutter, except it
uses a plastic extruder. This plastic extruder pushes out hot plastic
through a tiny hole and slowly, layer by layer deposits enough plastic
to build up a completed part.
Pick and Place Machine
A pick and place machine again uses a
similar set up as a CNC router or laser cutter. This time there a
multiple small nozzles, that pick up electrical components and then move
into a desired location and place that electrical component down. Hence
the name pick and place!
Pick and place machines move very quickly
and are used to place the many hundreds or thousands of electrical
components that make up devices such as computer motherboards, phones /
tablets, and pretty much everything else that has a printed circuit
board.
