CNC APPLICATIONS

From the start of the NC milling machine, there have been many applications for NC technology,ranging from milling, turning, electric discharge machine(EDM), punching and nibbling, forming, bending, inspection and robotics.

Although aerospace is still one of the principal industries that require and use NC technology extensively, other industries have also used it. Because of the continuing advances and affordability of computers, the cost of NC technology has been dropping rapidly to the point where even small machine shops and small specialty industries have come to require it. Today you can find NC products in trade areas like metal working, automotive, electronics, appliances, and furniture manufacturing.

ADVANTAGES OF CNC

CNC has grown to an ever increasing rate, and its use will continue to grow because of the many advantages that it has to offer industry. Some of the most important advantages of CNC are the following;

1. Greater operator safety- CNC system are generally operated from console away from the machining area, which is enclosed on most machines. Therefore the operator is exposed less tom moving machine parts or to the cutting tool.


2. Greator operator efficiency- A CNC machine does not require as much attention as a conventional machine allowing the operator to perform other jobs while it's running.


3. Reduction of scrap because of the the high degree of accuracy of CNC systems, Scrap has been drastically reduced.


4. Reduced lead time for production- The program prepation and setup for computer numerically controlled machines is usually short. Many jigs and fixtures formerly required are not necessary.


5. Reduction of human error- The CNC program reduces of eliminates the need for an operator to take trial cuts, make trial measurements, make positioning movements, or change tools.


6. High degree of accuracy- CNC ensures that all parts produced will be accurate and uniform quality.


7. Complex machining operations- Complex operations can be performed quickly and accurately with CNC and electronic measuring equipment.


8. Lower tooling costs- CNC machines generally use simple holding fixtures, which reduce the cost of tooling by as much as 70 percent. Standard turning and milling tools eliminate the need the need for special form tools.


9. Increase productivity- Because the CNC system controls all machine fuctions, parts are produced faster and with less setup and lead time.


10. Reduced parts inventory- A large inventory of spare parts is no longer necessary since additional parts can be made to the same accuracy when the same program is used again.


11. Greater machine tool safety- The damage to machine tools as a result of operator error is virtually eliminated since there is less operator intervention.


12. Less inspection required- CNC machines produce parts of uniform quality, less inspection time is required.


13. Greater machine use- Production rates could increase as much as 80 percent because less time is required for setup and operator adjustments.
14. Reduced space requirements- A CNC system requires fewer jigs and fixtures, and therefore less storage space

Types of CNC Machine Tools

There are many different types of CNC machine tools used in industry, such as;

1. Mills and Machining Centers
   
2. Lathes and Turning Centers
   
3. Drilling Machines
   
4. EDM Machines
   
5. Flame and Laser Cutting Machines
   
6. Water Jet Profilers

CNC MACHINING CENTERS

Machining Center is the latest development in CNC technology. These systems come equiped with automatic tool changer capability of changing many tools. Some machining centers are also fitted with movable rectangular worktables called pallets. The pallets are used to automatically load and unload work pieces. At a single setup, machining centers can perform such operations as milling, drilling, tapping, boring, counter boring and so on. Additionally by utilizing indexing heads, some centers are capable of executing these tasks on many different faces of a part and at specified angles. Machining centers save production time and cost by reducing the need for moving a part from one machine to another.

CNC TURNING CENTERS

Turning center with increased capacity of tool change is also making a strong appearance in modern production shop. These CNC machines are capable of executing many different of lathe cutting operations simultaneously on a rotating part.


CNC EDM MACHINES

In addition to machining center and turning center, CNC technology has also been applied to many other types of manufacturing equipment. Among these are wire electrical discharge machines (Wire EDM) and laser cutting machines.

Wire EDM machine utilizes a very thin wire (0.0008 to 0.012 in) as electrode. The wire is stretched between diamond guides and carbides that conduct the current to the wire and cuts the part like a band saw. Material is removed by the erosion caused caused by a spark that moves horizontal with the wire. CNC is used to control horizontal table movements. Wire EDM machines are very useful for producing mold insert, extrusion and trim dies, as well as formed tools.

CNC LASER CUTTING MACHINES

Laser cutting CNC machines utilize an intense beam of focused laser light to cut the part. Material under the laser beam undergoes a rapid rise in temperature and is vaporized. If the beam power is high enough, it will penetrate through the material. Because no mechanical cutting forces are involved, laser cut part with a minimum of distortion. They have been very effective in machining slot and drilling holes.