Archive for the ‘CNC’ Category


The CNC Family

Sunday, January 24th, 2010

When you think about CNC, what do you think of first? Which aspects of CNC are important, which are essential, and which ones can you take or leave? You be the judge.

You might have not heard of the CNC before, or what it does, or how it makes lofty manufacturing operations a lot easier. However, CNC machining is dubbed as one of the most important factors of most production processes. The common tasks CNCs machines usually perform are drilling holes, tool changing, cooling and lubrication of separate factory machines at the same time.

Let’s start with a brief introduction. CNC stands for Computer Numerical Control and it has been around since the early 1970’s. Before it was christened CNC, it was called NC, for Numerical Control. When computers were introduced during 1070’s, the name changed. It has stroked almost all manufacturing forms in almost all stages of production. CNC machines either substitute some existing manufacturing processes or combine work with them.

A CNC program is just any other set of instructions. It’s written like a sentence and the order of operation is chronological. The machine will then execute that set of instructions step-by-step. A special series of CNC words/codes are used to relay what the machine is supposed to do. CNC codes begin with letter addresses (like S for spindle speed, and X, Y & Z for common linear axis motions).

When certain codes are arranged together in a coherent method, this group of CNC codes create a “command” that is like a sentence. A common CNC machine will only be needing around 40-50 words/codes to program different commands. See, it’s not very difficult to learn.

Although CNC sounds very independent and do-it-all, there are a few words that you need to know to fully understand CNC operations.

THE CAM

Those of you not familiar with the latest on CNC now have at least a basic understanding. But there’s more to come.

CAM stands for Computer Aided Manufacturing. It simplifies the programming processes which are new, and added to the CNC program regularly. Of course, the easy applications can be programmed with only the simplest machines around: the pen, paper and calculator. However, more complex programs are vital regularly. It is when composing these programs become much more tricky and (worse) tedious.

The CAM is a program that runs on a computer that aids the CNC programmer with the programming. It also works hand-in-hand with the CAD (Computer Aided Design) design drawing (those designs engineers compose/nurture). With the CAM helping, redefinition of the work-piece configuration is not needed. What the CNC programmer is left to do is just to specify the machine operations to be executed and the CAM system will compose the CNC program automatically. Thanks to CAM, programming tediousness will not be a problem to the CNC programmer again.

THE DNC SYSTEM

DNC stands for Distributive Numerical Control. It is a computer that is connected with one or more CNC machines, forming a network. When a program is manually composed and ready to be loaded to the CNC control, it is being typed right into the control. However, this is like using the CNC machine as a luxurious keyboard.

Moreover, if the CNC program is achieved with the help of CAM, it is already in text form and ready to be loaded to the CNC control. The DNC simply distributes the CNC program to more than one CNC machine. Lately, the newest controls are more advanced in terms of networking capabilities and can be networked with, say, the Ethernet.

If it’s your first time to read and learn about the CNC, it may sound so mighty and ubiquitous. It’s about time you learn they also need help from some programming friends such as the CAM and the DNC. No man is an island; but hey, neither are CNC machines.

So now you know a little bit about CNC. Even if you don’t know everything, you’ve done something worthwhile: you’ve expanded your knowledge.

About the Author
By Anders Eriksson, feel free to visit my latest acquisition: Free Google Traffic System and make sure to visit my bonus site!

CNC Machine Setup and Operation

Thursday, January 21st, 2010

If you’re seriously interested in knowing about CNC, you need to think beyond the basics. This informative article takes a closer look at things you need to know about CNC.

Computer Numerical Control Machines are sophisticated instruments that only trained CNC operators should operate them. There are certain rules and guidelines to consider if you are planning to use a CNC machine by yourself.

CNC checklist before startup

Before starting up the Computer Numerical Control Machine, there are safety rules that must be considered first. First important aspect before starting up the CNC machine is to ensure your own safety, therefore wearing protective gear, such as eye glasses and short sleeved shirts is an important dress code during CNC operation. You should also be careful whenever you are handling tools and sharp edged work pieces to avoid any accidents. You must also ensure that the cutting tools are fastened in the machine spindle to avoid any movement during the cutting operation.

Actual Startup, Operation and Machine Setup of the CNC

The Computer Numerical Machine startup procedure varies depending with the type of machine being used but usually there is a main power switch or a circuit breaker to turn it on. Some machines also require hydraulics or air pressure before it starts up.

If you find yourself confused by what you’ve read to this point, don’t despair. Everything should be crystal clear by the time you finish.

When the Computer Numerical Machine starts up, the machine usually starts at its Machine Home Position. The Machine Home Position allows the control and the machine to have a preset starting position for all its axes. After startup, the CNC machine must be sent to this position before the work begins. This position will later be changed to an appropriate location whenever you are machining a particular part of a product.

The Tool Length Offset Value or TLO is the distance from the tip of the tool from the spindle in the Home Position. The TLO must be set for each tool in the current job. The TLO can be set using a height gage, fixture location, as well as the reference tool. When these values are determined, they are stored in the Controller to be used during the program operation.

After setting the Tool Length Offset Value it is time to setup a part origin of a CNC machine. Setting up the part origin on a CNC machine is the same as setting up a conventional machine. It usually involves positioning the axes to a point where the plan designates as its origin. There are many ways to locate the position on the reference point, it is by using edge finders, wigglers or magnifying glasses.

After setting up the whole system for the Computer Numerical Control, it is time to Load the program to the machine. Program loading is different for each machine. Some machines have tape readers to input the program into the Computer Numerical Control Machine’s memory. Newer machines have internal or external floppy devices to input the program to the machine. After the program is loaded to the machine, the CNC machine is now ready to use.

There are certain instances when you have to change the tools in the Computer Numerical Control manually during machine operations. When a certain machining operation is complete, the program will move the aces to the tool change position and display the next tool needed. It is now the job of the Machine operator to remove and replace it with the next tool.

Extra Care must be taken whenever you are starting operations with the CNC machine, any mistake taken during the part of the operation may lead to serious injuries from the machine operator.

About the Author
By Anders Eriksson, feel free to visit my latest acquisition: Free Google Traffic System and make sure to visit my bonus site!

Practical Applications of CNC

Monday, January 4th, 2010

Manufacturing anything that requires exact measurements requires cutting edge precision and nimbleness from the worker. Most of the time manufacturing these kinds of products requires weeks or months to finish therefore slowing down productivity as well as consistency of the manufacturers.

Computer Numerical Control or more commonly called as CNC’s are the new trend in machine shop manufacturing and practice. Any manufacturing environment owns one or is basically acquainted to this kind of device because of its capability to increase productivity as well as consistency on the products being produced.

Benchmarked from Numerical Control (NC) during the late 50’s, Computer Numerical Control incorporate the functionality of a Programmable Logic Controller (PLC), meaning you could program it to execute different functions depending on the type of manufacturing that the industry needs.

Given this kind of quality what does the Computer Numerical Control do in the practical application concept? CNC can do a variety of things depending on how the machine operator would program the system. The more acquainted the machine operator is to the CNC machine the more complex applications as well as programming can be made. Practical applications of CNC range from drilling, lathes, multi-axis spindles, milling machines, laser cutting machines, and wire electrical discharge machines.

Let’s discuss some of these common applications further. In Metal fabrication, Computer Numerical controlled Lathe’s are used to fabricate metal sheet by shearing, flame or plasma cutting, punching, laser cutting, forming and welding. Most CNC Lathe’s are used for designing modern carbide tooling. The design could be created with the Computer Aided Manufacturing (CAM) process, and when done, the CNC could start creating the product automatically with little supervision from the machine operator.

I trust that what you’ve read so far has been informative. The following section should go a long way toward clearing up any uncertainty that may remain.

Electrical discharge machining (EDM) is the process of removing metal with the use of electrical sparks to take away the metal. These Electrical Discharge Machine has two types, the vertical EDM and wire EDM. Vertical EDM uses an electrode that is the shape of the cavity to be machined into a work piece. Wire EDM is used to create punch and die combinations in the fabrication industry. Computer Numerical Control EDM’s are not usually known because it is mostly incorporated to other CNC process.

Drilling is the most common machine process. Computer Numerical Controlled Drilling is used to create precise right circular cylinders over a certain material, the CNC could be programmed to create holes on different standards, most of the time this is the gaps between these holes. Drilling is commonly used in wood working manufacturing process in which other process is also involved such as milling, turning and grinding.

Several tools for creating holes with CNC’s involve varied hole sizes as well as drill press for creating different depths on its holes. CNC drills are equipped depending on the type of hole that the machine operator is drilling.

Applications stated above are just a few examples on what the Computer Numerical Control could execute. Depending on how you want it to perform, more complex designs can be made and a lot of things can be made in a shorter period of time, therefore the key concept for the proper use of CNC’s is that the machine operator must know what he or she wants to do.

This makes the CNC an indispensable tool for the Manufacturing Industry nowadays.

It never hurts to be well-informed with the latest on CNC. Compare what you’ve learned here to future articles so that you can stay alert to changes in the area of CNC.

About the Author
By Anders Eriksson, feel free to visit my latest acquisition: Free Google Traffic System and make sure to visit my bonus site!

Programming CNC Machines With G-Codes

Thursday, December 31st, 2009

Are you looking for some inside information on CNC? Here’s an up-to-date report from CNC experts who should know.

Ever since the industrial revolution started, the demand to create precise instruments and products is an important factor in large scale manufacturing. Belts, screws, Drills and all movable parts needed to create other products in the assembly line must all be exact and compatible, thus extra care must be taken in order to ensure that all moving parts match perfectly. Computer Numerical Controlled programming has become an extremely important part of this process.

Computer Numerical Controlled Machines are useless without any programming. CNC’s rely on pure hard codes in order to execute commands that the Machine Operator wants to do, therefore not only is it needed to learn the mechanics of the whole Computer Numerical Controlled Machine but it is also at the utmost importance that the Machine operator knows how to communicate with the machine, and that is by using G-codes.

Preparatory code/ functions or much commonly called as G-codes are functions in the Computer Numerical Control programming language. The G-codes job is to manage the position of the tool as well as control the step by step commands during the actual work. Basically the G-codes are the most important part of the Computer Numerical Control Programming algorithm.

There are other codes involved in the programming of CNC’s such as M-codes that manages the machine, T-codes for managing the tools, and F-codes for the tool feed and tool speed controls. All of these codes are created in a Computer Aided Manufacturing (CAM) software.

G codes as well as the others use the RS-274D as the recommended standard for the Computer Numerical Controlled Machines. This standard was developed by the Electronic Industry association during the 1960’s. These standards provide a basis for the creation of Computer Numerical Controlled Programs.

First designs of these standards came from punched paper tapes as the medium standard for data interchange, but now ASCII character bit patterns are the standard for the representation.

Those of you not familiar with the latest on CNC now have at least a basic understanding. But there’s more to come.

G-Codes

Lets discuss the g-codes further, as what I have said earlier G- codes constitute only a part of the Computer Numerical Control Program, in the whole programming algorithm, they are denoted by the letter G, Basically it is a code telling the machine what kinds of actions to perform in a step by step basis, examples of these actions would be rapid move, controlled feed moves that would bore holes, a work piece cut routed to a specific dimension, change a pallet, and set a tool information such as offset.

After creating each part of the codes, the algorithm is compiled in the Computer Aided Manufacturing (CAM) software. The CAM software basically use translators called post processors to output the code optimized for a certain machine type. Often times, post-processors are often used to allow users to enable further customization.

G-codes can also be used to create outputs for Computer Aided Design systems used to design printed circuit boards (PCB). Any software must be customized for each type of machine tool that it will be used to program. Some G-codes are written by hand for volume production jobs.

Some Computer Numerical Controlled machines use conversational programming. Conversational programming is an easier way to program CNC machines because it is more “user friendly” because it uses a wizard like program that hides the G-codes into plain view. Some Popular examples of this kind of CNC machines are the Southwestern Industries’ Proto TRAK, Mazak’s Mazatrol, and Mori Seiki’s CAPS conversational software.

Conclusion

With these kinds of further sophistication in programming Computer Numerical Controlled Machines, it is expected in the future that programming would be much easier for its machine operators.

It never hurts to be well-informed with the latest on CNC. Compare what you’ve learned here to future articles so that you can stay alert to changes in the area of CNC.

About the Author
By Anders Eriksson, feel free to visit my latest acquisition: Free Google Traffic System and make sure to visit my bonus site!

CAM: A Vital Component of CNC

Friday, December 25th, 2009

The following article covers a topic that has recently moved to center stage–at least it seems that way. If you’ve been thinking you need to know more about it, here’s your opportunity.

Computer Aided Manufacturing started being used by automotive and aerospace component manufacturing companies. This sped up the manufacturing process and thus increased efficiency ratings. However, the introduction of CAD into the industrial sector did not eliminate the need for skilled professionals.

In fact, the operation of this program requires a higher degree of skill in terms of being computer literate.

Flaws

The CAM system is a flawless solution. However speedy the system becomes, it still has faults that may hamper production. Since CAM generates a code for the least capable machine, an improperly set CAM software required heavy manual editing. In this case, editing such a code is a tedious and drawn-out process that takes a lot of time and effort (something that big-time companies cannot spare).

Another problem that you have to face is the data exchange that has to take place when integrating CAM with other components (CAD/CAM/CAE PLM). It becomes necessary for the CAM operator to export the data in a more compatible data format. And since the output stack of CAM is a G-code text file—sometimes containing thousands of commands—the operator is then faced with a very serious time problem.

CAM cannot reason. In this case, it cannot figure out the right toolpath for mass production. Operators would still have to select the type of tool to be used, the machining process that should be followed, and the path to be used. This means that the CAM cannot adjust to wear issues and sudden changes. It needs to be reprogrammed to be able to work efficiently. Furthermore, mass production increases the likelihood of errors to occur in the production cycle.

Once you begin to move beyond basic background information, you begin to realize that there’s more to CNC than you may have first thought.

PROS

CAM can cut cycle time significantly. This means that with the proper people and the proper tools, a more efficient production method can be obtained. A lower cycle time means that you can produce more components in a lesser time. And since the main users of CAM and CNC are big manufacturers with deadlines, it is of the utmost priority to cut cycle time.

Another advantage that could be gained by CAM software is the increase in machine life. Since the process is automated, the system can keep track of certain variables that allow it to adjust to the conditions of the machine that is operating under it. This means that the life of the machine can be extended by adjusting the performance of the machine in order to avoid overworking it.

Quality can also be taken into account in this scenario. It is because the system also monitors slight differences in the production environment. Furthermore, the intricate designs that cannot be achieved by human engineers can be achieved by the machines. Also, these designs can be completed at a faster rate compared to manual operations. Another factor that should be considered would be the error ratio of the production of any components.

Conclusion

So, CAM is a very important aspect of production. However, the need for skilled operators still exists as programming and setting up these machines decide the fate of the manufacturing process. However, the increased automation and efficiency provided by such a system makes programming and setting up of these systems the only jobs of the operators.

This also allows operators to be more productive as they do not have to watch any single machine for more than the required amount of time.

That’s the latest from the CNC authorities. Once you’re familiar with these ideas, you’ll be ready to move to the next level.

About the Author
By Anders Eriksson, feel free to visit my latest acquisition: Free Adsense eBook and make sure to claim your free adsense ebook download!

People You Will Need When You Already Have A CNC Machine

Thursday, December 24th, 2009

If you think that you will just sit back and relax when you have a CNC machine in your shop, think again. CNC may help you speed up your operations and even make them more efficient. However, CNC is not a “wonder robot” which will make you disregard all your employees and expect your shop to run on auto-pilot.

Though you will need more people without the CNC technology, you will need only three very, very skilled people. Call these people your friends, your team, whatever. In the long run, they might be just all you need to keep the shop in good shape.

THE PROGRAMMER

The first person is the CNC programmer. S/he is like the “playmaker”. S/he will create the programs that the CNC machines are intended to execute. Since the programs are in the form of CNC codes fabricated like sentences, he should have mastered these codes because they work like a different language. The regular CNC machine can use up to 50 codes, so that’s like learning 50 new words for the newbie.

Also, the programmer should have at least and engineering or machining degree. Remember that the CNC machine will only execute WHAT IT IS PROGRAMMED TO DO. If the program is wrong, the whole operation goes down the drain with it. Moreover,s/he should also be flexible and have a fast turn-around because a CNC machine is often used to machine a huge selection of different work-pieces.

THE OPERATOR

It’s really a good idea to probe a little deeper into the subject of CNC. What you learn may give you the confidence you need to venture into new areas.

The second person that you need is the CNC operator. S/he will simply recheck the programs loaded to the machine and push the right buttons to get the work done. However, thinking that a CNC operator can have little or NO SKILL AT ALL is wrong. A CNC machine operator must have at least basic machining skills and s/he should have undergone some form of training to run a CNC machine.

These machines can produce very intricate motions, making it possible to make shapes that cannot be created on conventional machine tools. So, the operator should foresee this complexity and know how to cruise with it. The skills that an operator must have though, are lesser compared to the operators of conventional machine tools.

THE TECHNICIAN

The third person that will need is the CNC technician. Although this may still be the programmer, it’s more convenient to always have a technical expert on-call because in the long run, you may have more than one CNC machine and you may need to prioritize over the other in case both gets crippled at the same time. Just like the programmer, the technician should also be flexible and articulate. CNC offers a lot of complexity when it’s running right, how much more if it’s behaving badly?

So, if you are having job openings for positions that need to be handling a CNC machine, ask the applicants first to do a demo for you and make sure that during the demo, they know what they’re doing. An exam may also do wonders too. If they have no experience with any kind of CNC machine, it is advisable that you encourage them to take short courses on CNC.

Eighty-hour courses are available online and hey, it’s better than nothing. Experts even encourage employers to hire CNC machinists who have finished AND PASSED the National Occupational Competency Testing Institute (NOCTI) assessment just so they could be sure that their CNC machines will go to good hands. After all, a CNC machine is still an asset.

Of course, it’s impossible to put everything about CNC into just one article. But you can’t deny that you’ve just added to your understanding about CNC, and that’s time well spent.

About the Author
By Anders Eriksson, feel free to visit my latest acquisition: Free Adsense eBook and make sure to claim your free adsense ebook download!

Understanding CNC

Thursday, December 10th, 2009

You should be able to find several indispensable facts about CNC in the following paragraphs. If there’s at least one fact you didn’t know before, imagine the difference it might make.

Have you ever asked yourself how machines in a factory know exactly when to stop making the parts they’re supposed to make? Well, this is all because of Computer Numerical Control (CNC). But to understand CNC, you have to know what Numerical Control (NC) is.

HISTORY

NC machines were first introduced after the 2nd world war as mass production became the trend. These machines were given a set of instructions in punched cards. However, these machines were hard-wired and their parameters were difficult to change.

These NC machines still required a great deal of human intervention. To illustrate this point, try to take a look at a drill press. A lot of actions have to be taken in order to manufacture a product. The process is actually so complicated that a person has to do something almost every step of the production process. This created an avenue for errors to take place as the likelihood of fatigue increased with the quantity growth.

CNC then came into the picture when computers were introduced. Punched cards were replaced by floppy disks, cables, and other software transfer media. This made it easier to manage and edit data.

Production and manufacturing were revolutionized by the increased automation of CNC machines. These machines allowed a degree of added control over the quality and consistency of the components that were manufactured without any additional strain on the operators. This reduced the frequency of errors and allowed the operators time to perform additional tasks. Furthermore, this automation allowed a greater degree of flexibility in the way components are held in the manufacturing process.

It’s really a good idea to probe a little deeper into the subject of CNC. What you learn may give you the confidence you need to venture into new areas.

With the advent of Computer Aided Manufacturing (CAM), even programming CNC machines is a snap. These programs actually take the bulk of the programming process to make the operation less tedious. However, to be an effective programmer of CNC machines, you have to know what the machine you’re working on will be doing. That is why machinists are often the best people for the job.

The ease that the machines provide is hinged heavily on the quality of the machine. Low-cost CNC machines oftentimes have many functions that have to be manually activated. High-cost machines, however, are almost fully automated. The operator only has to load or unload workpieces. Once the cycle has been initiated, the operator just has to sit back and watch for any malfunctions. The stress on the operator is so low that some even complain of boredom in the middle of a cycle.

CODING

The programming language that CNC uses is called a G-Code. These codes actually position the parts and do the work. To be able to have a machine work properly, you have to input the correct variables such as axes, reference points, the machine accessories, and whatnot. Every machine has a different set of variables so you have to be careful to take note of the differences.

Aside from the G-Code, logical commands or parametric programming can be used to make the process more time-efficient. This type of programming language shortens lengthy programs with incremental passes. A loop can also be programmed thereby removing the need for coding repetitions.

Because of these features, parametric programming is more efficient than CAM. It allows users to directly and efficiently make performance adjustments. It also allows extensions to the functionality of the machine it is running on.

And that makes CNC.

There’s no doubt that the topic of CNC can be fascinating. If you still have unanswered questions about CNC, you may find what you’re looking for in the next article.

About the Author
By Anders Eriksson, feel free to visit my latest venture: GVO and make sure to claim your $1 trial membership!

How CNC Helps Companies

Sunday, December 6th, 2009

The advent of Computers lessened the need for human intervention in almost all aspects of our daily lives. This is especially true in the industrial sector now that production is virtually automated.

Precision and accuracy

Computer numerical control has been able to help companies in terms of precision. With the need for more complex designs and more complex operations, human workers could not cope with the required precision that comes with advancement. CNC machines were able to alter that idea by allowing increased precision and lesser error ratios with regards to production.

Another important improvement that CNC has brought with it is the increased accuracy. The dimensions of components have to be very accurate. And since an increase in production speed also increases the error ratio, CNC has helped lower that ratio by the increased level of automation and the error detection capabilities that computers have.

Speed

In the industrial sector, speed is of the essence. With CNC technology, the normal production capacity has been increased exponentially. This means that effective and accurate production methods have been developed. Mass production requires more scrutiny for errors and mistakes. However, anomalies can also be corrected. The programming structures of CNC machines can be altered in a fast way. This means that mistakes do not have as serious an impact as they had before CNC was improved to this level.

You may not consider everything you just read to be crucial information about CNC. But don’t be surprised if you find yourself recalling and using this very information in the next few days.

Machine versatility

CNC machines have become very versatile with regards to the tools that they use. They can easily be assigned to different tasks and thus can be very productive. Tools and networks can be switched without compromising the speed of the production. Aside from this, one machine can do more than one task at a time. This exceeds the normal human capacities as it allows more tasks to be accomplished at a faster rate than before.

Furthermore, when one machine tool breaks down, it can easily be pulled off the grid to prevent it from affecting the whole production cycle. It can then be replaced or repaired on the spot.

Lesser human intervention

Since component production is a very tedious and repetitive operation, human error skyrockets as time passes. This is due to fatigue and other factors. Furthermore, the ability of a person degrades due to psychological and emotional factors. This means that if a person works on the same job for a certain amount of time, the person may eventually get bored or tired or both. This increases the possibility for the human to commit an error and thus causes a drop in the efficiency rating of that person. A machine, however, does not get tired or bored. A machine does not have any concern at all.

Therefore, a machine increases efficiency ratings by speeding up production and eliminating or reducing factors that threaten efficiency. In this case, one must simply program the machine to start a cycle. Furthermore, humans have to be fed, paid, and rested. Machines only have to be rested when failures occur to often and they do not need to be paid or fed.

This brings us to the conclusion that companies will be able to save a lot in the long run. While investing in CNC machines is not cheap, maintenance will only cost a fraction of what will be paid to manual laborers.

About the Author
By Anders Eriksson, feel free to visit my latest venture: GVO and make sure to claim your $1 trial membership!

Cycle Time Reduction Principles for CNC Machining Equipment

Friday, November 27th, 2009

The more you understand about any subject, the more interesting it becomes. As you read this article you’ll find that the subject of CNC is certainly no exception.

What is the definition of cycle time?

Cycle time is defined to be the time that happens from the time a task or series of tasks is initiated to the time a task is completed. Example, the cycle time is the time a shipping order is printed to the time it is loaded on the truck and the system is updated. An alternate definition would be is the time it takes to load, run, and unload on workpiece.

Cycle time of a machine can be simply measured by timing how long it takes from pressing the button to start the cycle for the first workpiece to the pressing the next button for the next workpiece.

Production quantities in an industry dictate that the more workpieces you run, the more important it is to achieve the goal of lowering the cycle time.

Everything and anything that happens in a Computer Numerical Control (CNC) machining equipment can be divided into four categories:

1.) On-line, productive tasks:

These are the actual machining operations that occur during a CNC cycle. These are the milling, drilling, tapping, reaming, and any other machining operation that in some way furthers the completion of the workpiece. To minimize the cycle time in these areas, there are two ways in which this can be achieved. One would be through careful process planning.

The process engineer must select an appropriate machine tool, cutting tools, fixturing, and machining order in a way that it matches the number of workpieces to be machined that will be based on the production quantity. The cycle time will be a reflection of the processes being used to machine workpieces.

See how much you can learn about CNC when you take a little time to read a well-researched article? Don’t miss out on the rest of this great information.

If in the many times that your company’s processes have already been developed and implemented before you begin your cycle time reduction program, then your second alternative is to optimize cutting operations for this would involve properly selecting cutting tool materials, feeds, and speeds to machine workpieces as efficiently as possible with the current process.

2.) On-line, non-productive tasks:

These are tasks that occur during the machining cycle that do not actually further the completion of the workpiece. The first thing Computer Numerical Control people often target for improvement is wasted program execution time. These are the things like rapid movements, tool changes, M-code execution and spindle acceleration/deceleration. Reducing program execution time in this area is usually easy.

It often takes nothing more than carefully monitoring the production run for a few workpieces to find those times when the program can be modified to eliminate noticeable pauses during the cycle. Although keep in mind that the worker for these machines must not overlook other processes for they may be so concerned with minimizing program execution that they overlook other operations, resulting in severe wastes of cycle time.

3.) Off-line, non-productive tasks:

These are the tasks performed in the machining cycle that do nothing to further the completion of the workpiece. Since these types of tasks are done while the machine is producing workpieces, they do not actually add to the cycle time. It is possible to free the operator of the machines of performing off-line productive tasks if they have little, or nothing to do during lengthy machine cycles.

4.) Off-line, productive tasks:

These are the tasks done away by the CNC machine, while the machine is producing workpieces, which would further the completion of the workpiece. This is extremely helpful during lengthy CNC cycles, tasks in this category can reduce the time it takes to complete the production run dramatically, which would effectively reduce cycle time.

I hope that reading the above information was both enjoyable and educational for you. Your learning process should be ongoing–the more you understand about any subject, the more you will be able to share with others.

About the Author
By Anders Eriksson, feel free to visit my latest venture: GVO and make sure to claim your $1 trial membership!

Programming 101: CNC

Sunday, November 1st, 2009

After World War II, people realized that they have to manufacture goods at a faster rate and at a lower cost. Hence, mass production trending came to be. Those events led to the development of the Numerical Control (NC) machines which in turn led to the Computer Numerical Control (CNC).

HOW TO PROGRAM A CNC MACHINE

CNC programming uses a code similar in structure to BASIC. So, if you know how to construct a simple counting program, chances are, you already know what a G-Code looks like. However, there a few other things you have to consider before you start encoding instructions.

The first thing that you have to do is to assign values for each of the variables. These variables include the programmable motion directions (axes), and the reference point for the axes. The values that you assign to these variables dictate the movement of the machine.

The next thing that you have to do is to take into account the accessories of the machine. Many machines have accessories that are designed to enhance the capabilities of the basic device. However, using these accessories requires you to include them in the coding system. This means that if you want a more efficient machine, you will have to know the machine inside out.

READING CODES

After those steps, you have to create a subprogram that will deal with the math. This step will then allow your machine to compute the necessary variables and effectively operate without stopping to ask the operator what the limitations are.

I trust that what you’ve read so far has been informative. The following section should go a long way toward clearing up any uncertainty that may remain.

To show you what these codes look like, here’s an example from Wikipedia:

#100=3 (bolt circle radius)
#101=10 (how many holes)
#102=0 (x position of ctr of bolthole)
#103=0 (y position of ctr of bolthole)
#104=0 (angle of first hole
Tool call,
spindle speed,and offset pickup,etc
G43 in some cases (tool length pickup)
G81(drill cycle)
call sub program
N50
G80
M30

Subprogram
N100
#105=((COS#104)*#100) (x location)
#106=((SIN#104)*#100) (y location)
x#105 y#106 (remember your G81 code is modal)
If #100 GT 360 goto N50
#100=(#100+(360/#101))
Goto 100

In the code above, the machine is a drill. The operator utilized a loop in order to keep the machine from stopping. The subprogram then governs the cycle of the machine. This code is still quite a simple code. Other machines require the inclusion of the maximum RPM in the coding.

An easier way of programming CNC machines would be the use of Computer Aided Manufacturing (CAM). This system takes on the brunt of programming so that it doesn’t seem so tedious and frustrating. It is still similar to BASIC.

Another programming enhancement that was developed was the parametric programs or the logical commands. These programs were designed to shorten lengthy codes in order to make them user friendly. However, these codes do not always use the same language with every machine. The language and sequence often varies depending on the typ of machine you will be working on.

The operator has to know what the machine can do or what it was made to do before attempting to program it. You should be able to visualize the machine doing what you want it to do.

But, you don’t have to be a math wizard or a programming genius. You just have to know what your machine does and what you want it to do.

About the Author
By Anders Eriksson, owner of this excellent site: Product Profits Club (click to claim your FREE membership)