CNC Machines ( CNC mill programming ) advantages , disadvantages and How the system works
CNC machines ( Computer Numerical Control machines ) are widely used in manufacturing industry , The traditional machines such as the vertical millers , centre lathes , shaping machines , routers etc…. operated by a trained engineer have been replaced by computer control machines in many cases .
What is CNC machining ?
CNC stands for Computer Numerical Control , It refers to any machine that uses the computer to electronically control the motion of one or more axes , Modern CNC machines use the software programs to offer the instructions to control the axis motions , spindle speeds , tool changes , etc .
CNC machinery is used in the manufacturing sector , It involves the use of the computers that work to control the machine tools , There are many tools which can be controlled with the help of this system such as Mills , Routers , Grinders , Lathes , etc .
CNC machinery may seem like a regular functioning PC , however, it is a unique and well-developed software which is used to control machine tools , There is one person who can supervise many CNC machines as when they are programmed , they can be left to work by themselves , only the cutting tools need replacing occasionally .
The machine tools work through the numerical control , The computer software or rather program that is employed is customized for an object and the machines are programmed with the Computer Numerical Control language and it is referred to as the G- code .
This particular code is used to operate the features that include feed rate , coordination , speed as well as location , This particular procedure helps the computer to control the exact position as well as the velocity .
CNC machinery is very precise and it works better than the manual procedure , Unlike the manual procedure , It can produce any kinds of shapes including really complicated ones , especially 3D ones , They can keep repeating a particular system to be precise , This pattern is used to manufacture metal as well as plastic parts .
How CNC machining works ?
CNC machining works when a CAD drawing is done , The code is prepared or rather created which will be followed by the CNC machine , The code is loaded and tests are conducted to check if everything is working fine , After the trial run , the procedure takes place , This trial run is crucial as any mistake can lead to huge losses and damage .
CNC machines advantages
CNC machine can be used continuously 24 hours a day , 365 days a year and they only need to be switched off for occasional maintenance , They are programmed with a design which can then be manufactured hundreds or even thousands of times , Each manufactured product will be exactly the same .
There are less skilled/trained people who can operate CNCs unlike the manual lathes / milling machines etc.. that need skilled engineers , CNCs can be updated by improving the software used to drive the machines .
Training in the use of CNC machines is available through the use of virtual software , This is software which allows the operator to practice using the CNC machine on the screen of the computer and the software is similar to a computer game .
CNC machines can be programmed by advanced design software , enabling the manufacture of products which can not be made by manual machines , even those used by skilled designers / engineers .
When CNC machines are programmed correctly , They are usually 100% correct with what they produce , They can produce parts to maximise accuracy , They provide good positional accuracy and repeatability , They provide a high degree of quality because of their accuracy and their ability to reuse the programs .
CNC machines are very simple , They are not all that difficult to use once you learn how , complex fixtures are not required in all areas , The advanced machine control and programming capabilities allow for complex machining operations to be more easily accomplished .
CNC machines reduce the amount of time , They enable the operator to make changes or improvements with a minimum of delay or expense , They reduce the waste as the errors due to the operator fatigue , interruptions and the other factors are less likely to occur .
CNC machines improve the production planning as they can perform work at one setting that would normally require several conventional machines , They reduce lead time as a result of lower tooling costs .
CNC machines can be used throughout the year with very little maintenance , They can work repeatedly , producing the exact same result , The way the machines are programmed helps them manufacture thousands of times , We can easily improve the software and update the machine .
Many products can’t be manufactured with the help of manual machines , These machines are programmed using very advanced design software that makes it possible to manufacture such products very easily .
CNC machines helps cut down on a lot of employees as only one person can supervise several machines , They help save a lot of time & money , They can repeat their manufacture and all the products will be exactly the same unlike manual manufacture .
CNC technology allow multiple axes of simultaneous motion , resulting in 2D and 3D , It can move along a sloped line or circular trajectory , when one good part is produced on a CNC , it is going to do the exact same thing every time , So , CNC technology is beneficial for the purpose of mass production ( producing large quantities of the identical parts ) .
CNC machines disadvantages
CNC machines are more expensive than manually operated machines , although the costs are slowly coming down , The CNC machine operator needs basic training and skills only , enough to supervise several machines .
As with any business , The costs are always a factor , CNC machinery costs more than conventional machinery , It does not eliminate the need for expensive tools , The parts ( ie machines and tooling ) are costly and their purchase requires extensive justification and they are expensive to repair .
There are less workers who are required to operate CNC machines compared to manually operated machines , They do not need skilled engineers , their skills are being completely wasted , The years of training & education is being neglected , only minimum people are required for the supervision , So , CNC machines can cause a lot of unemployment .
CNC machinery does not totally eliminate the errors , The operators can push the wrong buttons , They can make incorrect alignments and fail to locate the parts properly on a jig .
CNC machines are more expensive , Machine tooling is roughly twice as expensive as well , They require programming skill set , CNC machines require more knowledgeable and thus higher paid operators .
CNC machines require more space , electricity and maintenance than manual machines , Because of the enclosures and electrical cabinets , They require more floor space , their larger spindles require more power and like any other computer , They require more maintenance than manual machines which have no computers .
It is slower and more expensive for making one simple part , Because of the amount of time , It is required to write a program , It is required to debug the inevitable errors , load the tools & teach the machine , how long they are , etc , it is faster to make one simple part on a manual machine .