CNC is short for Computer Numerical Control and has been around since the initial 1970’s. Just before this, it was actually called NC, for Numerical Control. (During the early 1970’s computers were exposed to these controls, hence the name change.)
While folks most avenues of life have never heard of this term, CNC has touched nearly every type of manufacturing process in one way or another. If you’ll be working in manufacturing, it’s likely that you’ll be dealing with CNC frequently.
While there are actually exceptions to this particular statement, CNC machines typically replace (or work along with) some existing manufacturing process/es. Take among the simplest manufacturing processes, drilling holes, as an example.
A drill press can of course be used to machine holes. (It’s likely that almost everyone has seen some type of drill press, even if you don’t function in manufacturing.) An individual may place a drill within the drill chuck that is secured in the spindle of your drill press. They can then (manually) find the desired speed for rotation (commonly by switching belt pulleys), and activate the spindle. Chances are they manually pull on the quill lever to get the drill in the workpiece being machined.
That you can easily see, there is a lot of manual intervention required to use a drill press to drill holes. One is needed to take action almost every step in the process! Even if this manual intervention may be suitable for manufacturing companies if but a small number of holes or workpieces has to be machined, as quantities grow, so does the chance for fatigue because of the tediousness of your operation. And do be aware that we’ve used one of several china machining parts operations (drilling) for our own example. There are many complicated machining operations that could need a higher capability (and increase the potential for mistakes causing scrap workpieces) of the individual running the traditional machine tool. (We commonly reference the fashion of machine that CNC is replacing because the conventional machine.)
In comparison, the CNC equivalent for the drill press (possibly a CNC machining center or CNC drilling & tapping center) may be designed to perform this operation in an infinitely more automatic fashion. Precisely what the drill press operator was doing manually will be performed by the CNC machine, including: placing the drill inside the spindle, activating the spindle, positioning the workpiece beneath the drill, machining the hole, and turning away from the spindle.
There is another article contained in this website known as the Basics of CNC that explains how to program, setup, and operate CNC machines in greater detail. Additionally, we offer a series of products aimed at assisting you learn to use CNC machines. Here we’re relating how CNC works in very general terms.
As you might have guessed, precisely what an operator would be asked to do with conventional machine tools is programmable with CNC machines. After the machine is setup and running, a CNC machine is pretty simple to keep running. In reality CNC operators often get quite bored during lengthy production runs since there is so little to perform. With a bit of CNC machines, the workpiece loading process is automated. (We don’t mean to in excess of-simplify here. CNC operators are generally expected to do other stuff relevant to the CNC operation like measuring workpieces and making modifications to maintain the CNC machine running good workpieces.)
All CNC machine types share this commonality: They all have 2 or more programmable directions of motion called axes. An axis of motion might be linear (along a straight line) or rotary (along a circular path). One of the primary specifications that implies a CNC machine’s complexity is just how many axes it has. In most cases, the better axes, the more complex the machine.
The axes of the CNC machine are required just for inducing the motions necessary for the manufacturing process. Inside the drilling example, these (3) axis would position the tool across the hole to be machined (in two axes) and machine the hole (with the third axis). Axes are named with letters. Common linear axis names are X, Y, and Z. Common rotary axis names certainly are a, B, and C.
A CNC machine wouldn’t be very helpful if all it could possibly only move the workpiece in several axes. Nearly all CNC machines are programmable in a number of different ways. The precise CNC machine type has a lot to do with its appropriate programmable accessories. Again, any required function will be programmable on cnc machining parts. Below are a few examples for just one machine type.
Think of giving any series of step-by-step instructions. A CNC program is merely another type of instruction set. It’s designed in sentence-like format and also the control will execute it in sequential order, in depth.
A particular series of CNC words are employed to communicate just what the machine is supposed to do. CNC words start with letter addresses (like F for feedrate, S for spindle speed, and X, Y & Z for axis motion). When placed together inside a logical method, a small group of CNC words constitute a command that resemble a sentence.
For almost any given CNC machine type, there will only be about 40-50 words used regularly. When you compare understanding how to write CNC programs to learning an overseas language having only 50 words, it shouldn’t seem overly difficult to learn CNC programming.
The CNC control will interpret a CNC program and activate the series of commands in sequential order. Mainly because it reads this program, the CNC control will activate the proper machine functions, cause axis motion, and in general, follow the instructions given inside the program.
Along with interpreting the CNC program, the CNC control has several other purposes. All current model CNC controls allow programs to get modified (edited) if mistakes are located. The CNC control allows special verification functions (like dry run) to ensure the correctness of the CNC program. The CNC control allows certain important operator inputs to be specified outside of the program, like tool length values. On the whole, the CNC control allows all functions from the machine to be manipulated.
For simple applications (like drilling holes), the CNC program might be developed manually. That may be, a programmer will take a moment to write this system armed simply with pencil, paper, and calculator. Again, for easy applications, this can be the most effective strategy to develop CNC programs.
As applications find more complicated, especially when new programs will be required on a regular basis, writing programs manually becomes considerably more difficult. To simplify the programming process, your personal computer aided manufacturing (CAM) system can be used. A CAM product is a software program that operates on a pc (commonly a PC) that assists the CNC programmer using the programming process. Most of the time, a CAM system can take the tediousness and drudgery out of programming.
In numerous companies the CAM system will continue to work with all the computer aided design (CAD) drawing designed by the company’s design engineering department. This eliminates the demand for redefining the workpiece configuration towards the CAM system. The CNC programmer will surely specify the machining operations to become performed and also the CAM system will create the CNC program (much like the manual programmer would have written) automatically.
As soon as the program is developed (either manually or by using a CAM system), it needs to be loaded to the CNC control. Even though the setup person could type this system straight into the control, this could be like making use of the CNC machine as a very expensive typewriter. In the event the CNC program is developed with the aid of a CAM system, then its already in the form of a text file . In the event the program is written manually, it might be typed into any computer by using a common word processor (though some companies utilize a special CNC text editor for this function). In either case, this program is by means of a text file that could be transferred straight into the CNC machine. A distributive numerical control (DNC) technique is used for this specific purpose.
A DNC technique is nothing more than a pc that is certainly networked with more than one CNC machines. Until only recently, rather crude serial communications protocol (RS-232c) needed to be utilized for transferring programs. Newer controls get more current communications capabilities and can be networked in more conventional ways (Ethernet, etc.). No matter what methods, the CNC program must needless to say be loaded into the CNC machine before it can be run.
As stated, CNC has touched virtually every component of manufacturing. Many machining processes have already been improved and enhanced through the use of CNC. Let’s examine some of the specific fields and set the emphasis on the manufacturing processes enhanced by CNC machine usage.
Machining processes which may have traditionally been done on conventional machine tools which are possible (and perhaps improved) with CNC machining centers include all kinds of milling (face milling, contour milling, slot milling, etc.), drilling, tapping, reaming, boring, and counter boring.
In similar fashion, all kinds of turning operations like facing, boring, turning, grooving, knurling, and threading are done on CNC turning centers.
There are actually all sorts of special “off-shoots” of these two machine types including CNC milling machines, CNC drill and tap centers, and CNC lathes.
Grinding operations of all sorts like outside diameter (OD) grinding and internal diameter (ID) grinding may also be being carried out on CNC grinders. CNC has even showed a new technology when it comes to grinding. Contour grinding (grinding a contour in a similar fashion to turning), which was previously infeasible due to technology constraints is now possible (almost commonplace) with CNC grinders.
In manufacturing terms, fabrication commonly means operations which are performed on relatively thin plates. Think of a metal filing cabinet. All of the primary components are constructed with steel sheets. These sheets are sheared to size, holes are punched in appropriate places, along with the sheets are bent (formed) for their final shapes. Again, operations commonly described as fabrication operations include shearing, flame or plasma cutting, punching, laser cutting, forming, and welding. Truly, CNC is heavily involved with virtually every facet of fabrication.
CNC back gages are normally used with shearing machines to manage the size of the plate being sheared. CNC lasers and CNC plasma cutters can also be utilized to bring plates to their final shapes. CNC turret punch presses can hold various punch-and-die combinations and punch holes in every sizes and shapes through plates. CNC press brakes are employed to bend the plates into their final shapes.
Electrical discharge machining (EDM) is the process of removing metal by making use of electrical sparks which burn away the metal. CNC EDM comes in two forms, vertical EDM and Wire EDM. Vertical EDM requires the usage of an electrode (commonly machined on a CNC machining center) which is from the shape of the cavity to get machined to the workpiece. Picture the shape of any plastic bottle that really must be machined right into a mold. Wire EDM is normally accustomed to make punch and die combinations for dies sets employed in the fabrication industry. EDM is probably the lesser known CNC operations because it is so closely related to making tooling combined with other manufacturing processes.
Like the metal removal industry, cnc milling parts are heavily found in woodworking shops. Operations include routing (comparable to milling) and drilling. Many woodworking machining centers are chinbecnnc that could hold several tools and perform several operations around the workpiece being machined.
Great shape of lettering and engraving systems use CNC technology. Waterjet machining uses a high pressure water jet stream to slice through plates of material. CNC is even utilized in the manufacturing of many electrical components. For example, you can find CNC coil winders, and CNC terminal location and soldering machines.
There is quite a shortage of skilled men and women to utilize CNC machines. And the shortage is growing. Everywhere I go I hear manufacturing people claiming they cannot find skilled people. Unfortunately, it has been specifically my experience that pay scales have not reflected this shortage. Having said that, you may make an excellent wage and establish a rewarding career working with CNC machines. Here are the job titles of individuals utilizing CNC machine tools.