Precision Machinery Definition

Numerical control (also computer numerical control, and commonly called CNC) is the automated control of machining tools (milling, drilling, boring tools, lathes-turning).

A CNC machine processes a piece of material (metal, plastic, wood, ceramic, or composite) to meet specifications by following a Computer Aided Machining (CAM) instruction and without a manual operator.

Vietnam Outsourcing (VNO) works with Vietnamese manufacturers that have different machine shops set up for different application.With high-end CNC machine (3 axis to 5 axis) and experience CAD and CAM designers and operators, Vietnam Outsourcing (VNO) is able to manufacture high-end products from different industries, ie: semiconductor, electronic component, oil&gas, automotive parts s, etc...

We also work with a series of more conventional machines with open chamber and bigger work tables that are suitable for manufacturing components of other industrial applications.

1. What is CNC machining?

So, we now know what CNC stands for and how CNC machines work. But not all CNC machines are used for CNC machining..CNC machining refers to only a few of these automated processes. Namely milling, turning, grinding, routing, drilling, etc.

t is an operation where the cutting tool rotates. When the milling tool comes into contact with the workpiece, it removes chips from it.

Milling operations include:

End milling
Chamfer milling
Face milling
Drilling, boring, tapping, etc.

It is a very universal fabrication method with great accuracy and tolerances. Milling is suitable for a variety of materials and is also very quick. The ability to manufacture a wide range of complex parts is a great advantage.

The disadvantages include a large amount of waste, need for a variety of tooling and high cost of equipment.

CNC Turning

While the two are often called just CNC machining, turning and milling have distinct differences. Turning, or lathing is pretty much the opposite of milling. This means that instead of the cutting tool, the workpiece is rotating.

A CNC lathe is commonly used for producing shafts, for example. The tool is brought against the rotating workpiece to cut off bits of metal, known as chips or swarf.

Turning is usable on the outside of a cylinder or on the inside. The latter operation is called boring.

CNC Grinding

CNC grinding machines are machine tools which use a rotating grinding wheel to achieve material removal on a metallic workpiece by means of cutting. Grinding machines are mostly used for the hard-fine machining of workpieces (parts). The surface quality which can be achieved is very high, and grinding machines thus almost always find application in modern industry as a finishing process. Furthermore, through the increased performance of the grinding tools, grinding machines can now be used to achieve high material removal rates (Q’w [mm³/(mm*s)] during production grinding
.
Besides the high machining performance possible with today’s CNC grinding machines during the actual grinding process, the loading and unloading of the workpieces is often also carried out fully automatically using automated loading facilities. This is referred to as an “unmanned operation”, where a sporadic check of the CNC grinding machine or the grinding process is all that is required. For the machining process itself, the continual presence of a worker at the CNC grinding machine is no longer necessary.

CNC Routing

A CNC router is similar to a CNC mill. It comes with the ability to use computer numerical control to route tool paths that enable the machine to function. CNC routers reduce waste and increase productivity, producing various items in a much shorter amount of time than using other machines.

CNC Drilling

Computer Numerical Control (CNC) Drilling is commonly implemented for mass production. The drilling machine, however, is often a multi-function machining center that also mills and sometimes turns. The largest time sink for CNC drilling is with tool changes, so for speed, variation of hole diameters should be minimized. The fastest machines for drilling varying hole sizes have multiple spindles in turrets with drills of varying diameters already mounted for drilling. The appropriate drill is brought into position through movement of the turret, so that bits do not need to be removed and replaced. A turret-type CNC drilling machine is shown below.

2. What is G and M code in CNC Programming?

G and M codes are numbers and latter that are used to write a CNC programming, CNC machines only understand the G and M codes.this article is about G and M codes.

What is G-Code in CNC programming

Preliminary capacities, called G codes, are utilized to decide the geometry of hardware developments and working condition of the machine controller; capacities, for example, straight cutting developments, penetrating tasks and determining the units of estimation. They are regularly modified toward the beginning of a square. G-code is a programming dialect for CNC that trains machines where and how to move. Most machines talk an alternate “tongue” of g-code, so the codes fluctuate contingent upon the sort, make, and model. Each machine accompanies a guidance manual that demonstrates that specific machine’s code for a particular capacity. G CODE

What is M-code in CNC programming

Various capacities, called M codes, are utilized by the CNC to direction on/off signs to the machine capacities. ie, Mø3 – shaft forward (CW), Mø5 – axle stop, etc…. The capacities distributed to bring down M code numbers are consistent in most CNC controls, in spite of the fact that the higher M code number capacities can change starting with one make of controller then onto the next The line of a program may likewise incorporate m-codes, which are for the most part codes that advise a machine how to play out an activity.

3. How does a CNC machine work?

A CNC machine is a computer controlled carving machine. It generally speaking reads G Code that instructs the machine how to move, what feedrate and spindle speed to use, which cutting tool should be in the spindle, etc. The cutter that the machine has in the spindle will carve through the material (generally metal) and create the intended shape. The material that has been removed is called "chips" and it will usually be recycled.

In most cases a CNC machine is programmed by a programmer using CAM software who uses the software to apply tool paths to a 3D or 2D model of the part they want to make. Once the programmer has finished his/her programming work, the program is fed into a post processor which will turn the CAM program into the G code the machine can read. The G code is uploaded into a the CNC machine along with all the cutting tools needed, raw material and work holding needed to hold the raw material. Then a machinist will put the machine into automatic mode and start the program to make the part.

4. The situation of Vietnam CNC machining

Despite the high price of CNC machines, the needs of businesses in Vietnam are huge
Supply source: mainly imported machine

In our country, imported machines have two main groups of machines

1. The CNC machines are made by Taiwan and China
2. CNC machines of developed countries such as Japan, Germany
3. Domestic manufacturing machines, there are 2 manufacturing trends exist in parallel
- The trend of buying used "old machines"
- Trend of manufacturing components of machine structure and assembly in Vietnam

5. CNC MACHINE APPLICATION IN VIETNAM

CNC machine was born as a new turning point of the era of scientific and technological development. Therefore, many fields have used this type of machine, especially the field of mechanics. People can use CNC machines to process different types of products from wood to stone and metal.

- In the field of furniture manufacturing, CNC machines are used to process patterns and engrave details quickly.
- In the areas of manufacturing household appliances and assembling vehicles, CNC machines are also used to process molds, for sophisticated designs.
- In the field of steel structure machining, CNC cutting machines are used to cut complex metal shapes with absolute precision. CNC cutting torch is used to cut oxygen, plasma and more advanced than laser cutting.