How to Purchse CNC Cutting Machines

This article was reprinted from Yeah!Legend Blog:

http://yeahlegend.com/blog/?p=111

At present, CNC flame and plasma cutting machines begin to be widespread among manufacturing enterprises in China. In order to improve production efficiency, expand production scale, many companies began to purchase and use CNC cutting machines. Due to lack of concepts and knowledge of CNC cutting, these companies would suffer technical problems and using difficulties when purchasing and using CNC cutting machines. Here is an article, introducing ways of purchasing or selling CNC cutting machines.

Simply, CNC cutting machine contains three parts:

一、Machine Tool

二、CNC System

三、Optimized Nest Software

1. Machine tool is the main body of CNC cutting machine, including crossbeam and guide rail, rack/gear wheel drive system, reducer, servo motor system, air circuit system, lift system, electric control cabinet, along with THC system, automatic ignition system, scoring system, cooling system, etc. Quality and processing precision of machine tool, purchase of key component (reducer, servo drive, THC, etc.) are important parts that will influence functional allocation, lifespan of machine tool, cutting quality and precision.

2. CNC system plays an important role as chief commander of CNC cutting machine. It mainly contains an industrial controller and a set of software specialized for CNC cutting and cutting controller software. The hardware configuration of industrial controller in CNC system determines the steady of CNC cutting machine and CNC system. Cutting control software in CNC system offers all kinds of cutting skill and motion control mode, determining the cutting efficiency and cutting quality of CNC cutting machines.

3. Optimized nest software is the necessary tool for efficient use of CNC cutting machine. Its key functions are as follows, 1. centralized nest of components and steels, especially the whole plate optimized nest and rest plate optimized nest, effectively improving the use ratio of steel plate nest. 2. Nesting programming and cutting efficiency. Through automatic and manual interactive fast nesting, automatic programming and efficient cutting technologies, working efficiency of nesting programming and cutting efficiency have been improved greatly.

Three main features of a CNC cutting machine:

1. Be able to cut certain plate with specific material and thickness, serving for specific products;

2. Be able to improve cutting efficiency and cutting quality;

3. Be able to save steel plate and consumables effectively.

How to choose specific type and equipment of CNC cutting machine? According to cutting materials and thickness, requirement for cutting efficiency and cutting quality, company could firstly select the type of CNC cutting machines, such as flame, plasma, laser or CNC groove cutting machine. Secondly, company should get to know the efficient pierce capacity and pierce technology in order to ensure the specific equipment of CNC cutting machines, such as types of plasma power, flame torch and preheat cutting oxygen equipment or CNC groove cutting method. Therefore, the equipment of CNC cutting machine and price can be settled.

SteelTailor Tells You How to Purchase Plasma Power and Plasma Cutting Machines

This is reprinted from Yeah!Legend Blog:

http://yeahlegend.com/blog/?p=105

Plasma power is an important equipment of plasma CNC cutting machine. Besides of greatly improving cutting efficiency and quality, plasma power could save the purchasing cost of CNC cutting machine. We’d like to list several notes about how to choose plasma power:

First of all, we need to know the requirements. Plasma cutting power includes machine-used plasma power and hand-held plasma power. Generally speaking, CNC cutting machines need machine-used plasma power. Speaking to arcing, plasma power has two ways, touching arcing and non-touching arcing (button). At present, CNC cutting machines prefer non-touching arcing. If there is a button on hand-held torch, it means this non-touching arcing will be used. The electric current of plasma power with non-touching arcing is generally above 100A. The electric current of machine-used plasma power is also larger than 100A. It is an important feature for power supply of 100A electric current that it will cause great radiation and probably cause damage to operators.

Second, plate thickness is required to be considered when choosing electric current of plasma power. Plasma power with different Watt share will share different price.From the consideration of cost, higher the Watt is, more power consumption and higher price.

Thirdly, we choose type and manufacturer of plasma power according to the requirement of quality of cutting section. Plasma cutting would cause the cutting notch large upside and small downside because of features of plasma arc. Cutting section is always tilted and could be as vertical as flame cutting. The slant angle for common plasma is about 13 to 15 degrees. Plasma power could be classified as common plasma, fine plasma and Laser-like plasma in terms of vertical degree and cutting precision. The cutting quality is, of course, related to the price. 

Fourth, plasma power contains inverter type and SCR. The former one is lighter.

Fifth, plasma power could be equipped to hand-held cutting, as well as one part of CNC cutting machine package. To realize the clamping on CNC cutting machine, CNC straight handle torch shoule be considered in procurement.

Sixth, the length of plasma cable should be related to the distance between torch and plasma power in full width during cutting process. If the cable is too long, the arc punching and cutting capability of this machine would be reduced.

Seventh, plasma power contains domestic plasma power and imported plasma power. The model and cutting condition of plate decide the specific choice of plasma power. In order to achieve good cutting effect, the quality of cutting machine and the skilled operation bear important responsibility.

How to Maintain CNC Plasma Cutting Torch

This article is reprinted from YeahLegend blog:
http://yeahlegend.com/blog/?p=102

Plasma cutting torch is the largest consumption among the consumables from the perspective of plasma cutting method. How yo extend the lifespan of plasma cutting torch during plasma cutting process? Several tips are as follows:

1. To assemble cutting torch correctly

We should assemble cutting torch carefully and correctly to make sure all the components are matched well, gas and cooling air are circulating smoothly. All the components should be placed in clean lint before assembly for avoiding dirt. Proper lubricating oil should be added into O-Ring till O-Ring becomes bright.

2. To change the consumables before complete breakdown

The worn electrode, nozzle and swirl ring will cause plasma arc and brought destructive damage to cutting torch. Therefore, consumables should be checked in time once we found the cutting quality is not as good as before.

3. To clean the connecting thread of cutting torch

When changing consumables or making daily maintenance, cutting torch and external thread should be clean. If necessary, the connecting thread should be washed or repaired.

4. To clean the surface of electrode and nozzle

Generally speaking, the surface of nozzle and electrode is electric. If dirt was in the surface, cutting torch could not work as usual. Oxidation of hydrogen cleaner should be used to clean away the dirt.

5. To check the gas and cooling air everyday

Gas, flow and pressure of cooling air should be checked everyday. If the flow is not sufficient or gas is leaked out, machine should be shut down and solve the problems first.

6. To avoid crash and damage to cutting torch

In order to avoid crash and damage to cutting torch, programming should be made correctly and avoid the system walk out of the limitation. AVTHC (Arc Voltage Torch Height Control) or anti-collision device should be installed for avoiding crash or any damage to cutting torch.

CNC plasma cutting machine is relatively more expensive than CNC flame cutting machine. But in the long term, flame cutting machine will consume more. What we should do is to protect the cutting components and cutting torch correctly. Therefore, plasma cutting is more economical and practical than flame cutting.

What is Cutting Torch of CNC Plasma Cutting Machines?

This article is reprinted from Yeah!Legend Blog:

http://yeahlegend.com/blog/?p=97

Almost all the internal components of plasma cutting machines are not special. But cutting torch, electrode, nozzle and swirl ring are conventional parts from the perspective of cutting torch. In practical application, different brands of plasma cutting machines vary in terms of maintenance of surface of cutting materials, cutting precision and balance of cutting speed. This is the key to the technology of plasma cutting machines.

We have to process with the components of cutting torch when we get to know the plasma cutting machines. Inside the cutting torch of plasma cutting machines, electrode is in the center, nozzle is under the electrode. Since electrode and nozzle are consumables of plasma cutting machines, they could be switched and changed easily; The upper orange component is swirl ring, which makes a round of swirl when plasma gas passed through. This is a whole set of cutting torch.

When plasma cutting machines work, nitrogen, argon or compressed air of oxygen will be given out through a narrow pipeline. The negative electrode is in the middle of the pipeline. A electric circle was created when negative electrode was changed and made nozzle touch the metal. At that moment, electric spark was created between electrode and metal. When inactive gas pass through pipeline, electric spark will heat the gas till the matter reached the fourth condition. In the process of reaction, plasma flow was produced with temperature of 16,649 C, flow velocity of 6,096 meters/sec, which could make metal become cinder immediately.

Electric will flow through the plasma. Continued changing to electrode and keeping touch between plasma and metal will make the period of the arc successive. To ensure touch while avoid oxidation or damage caused by any special feature of plasma, another pipeline was assembled on the nozzle of cutting machines. This pipeline continuously emit protective gas to protect the cutting area. To protect the pressure of gas could efficiently control the radius of columnar-type plasma.

What Makes Nozzles of CNC Flame Cutting Machines Out of Work?

Cutting process of CNC flame cutting machines is actually the process of steel-plate burning. The burning gas will support the flame cutting; Sometimes, gas could not be omitted in CNC flame cutting process. What caused this? We’d like to put forward several common causes according our experience.

1. Spring on Valve Plug of CNC flame cutting machine could not work because of efficient elasticity;

2. A little debris is inside the valve plug of CNC flame cutting machine. The debris would be accumulated inside the gas or the scrap iron will block or jam the valve plug in processing procedure.

3. When CNC flame cutting machines hold too much pressure, magnetic valve could not work efficiently.

4. The spring washer of CNC flame cutting machines is deformed or damaged;

5. Valve plug of CNC flame cutting machines had been used for a long time, or the valve plug was damaged because of improper protection. Therefore, the force of frication became too much;

At present, companies who need steel-plate will buy CNC flame cutting machines, CNC plasma cutting machines for they want to realize flame and plasma cutting. Flame cutting works slower than plasma cutting. But flame cutting would not cause residue, and it has no slope. So the flame cutting has still gained great popularity among users who use common carbon plate of 5-200mm. Of course, plasma cutting machines enjoy a high efficiency of cutting and wide cutting range. Customers could order the machines according their own demand.