CNC represents Computer Numerical Control and has been around since the initial 1970’s. Just before this, it absolutely was called NC, for Numerical Control. (In the early 1970’s computers were brought to these controls, hence the name change.)
While individuals most walks of life have never read about this term, CNC has touched just about every method of manufacturing process in one method or another. If you’ll work in manufacturing, it’s likely that you’ll be handling CNC on a regular basis.
While there are exceptions to this statement, CNC machines typically replace (or work along with) some existing manufacturing process/es. Take one of the simplest manufacturing processes, drilling holes, for example.
A drill press can needless to say be used to machine holes. (It’s likely that everyone has seen some form of drill press, although you may don’t operate in manufacturing.) An individual can place a drill inside the drill chuck which is secured inside the spindle from the drill press. They are able to then (manually) select the desired speed for rotation (commonly by switching belt pulleys), and activate the spindle. They then manually pull on the quill lever to get the drill in to the workpiece being machined.
That you can easily see, there is lots of manual intervention required to use a drill press to drill holes. An individual is needed to take steps nearly every step along the way! While this manual intervention might be appropriate 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 due to the tediousness of your operation. And do remember that we’ve used one of the china CNC machining operations (drilling) for your example. There are far more complicated machining operations that could require a much higher level of skill (and increase the chance of mistakes contributing to scrap workpieces) of the individual running the standard machine tool. (We commonly refer to the fashion of machine that CNC is replacing as the conventional machine.)
In contrast, the CNC equivalent for any drill press (possibly a CNC machining center or CNC drilling & tapping center) could be programmed to perform this operation in a far more automatic fashion. Everything that the drill press operator was doing manually will be done by the CNC machine, including: placing the drill in the spindle, activating the spindle, positioning the workpiece within the drill, machining the hole, and turning off of the spindle.
There is certainly another article a part of this web site referred to as Basics of CNC that explains how you can program, setup, and operate CNC machines in greater detail. Additionally, we provide you with some products aimed at assisting you discover ways 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. When the machine is setup and running, a CNC machine is fairly easy to keep running. In fact CNC operators have a tendency to get quite bored during lengthy production runs because there is so little to perform. With some CNC machines, even workpiece loading process continues to be automated. (We don’t mean to over-simplify here. CNC operators are typically necessary to do other activities relevant to the CNC operation like measuring workpieces and making modifications to retain the CNC machine running good workpieces.)
All CNC machine types share this commonality: Each one has two or more programmable directions of motion called axes. An axis of motion may be linear (along a straight line) or rotary (along a circular path). The first specifications that implies a CNC machine’s complexity is the way many axes it offers. Generally, the more axes, the greater number of complex the machine.
The axes for any CNC machine are essential for the purpose of inducing the motions essential for the manufacturing process. Inside the drilling example, these (3) axis would position the tool on the hole to be machined (in 2 axes) and machine the hole (with all 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 useful if all it could possibly only move the workpiece in two or more axes. Just about all CNC machines are programmable in numerous alternative methods. The specific CNC machine type has a lot concerning its appropriate programmable accessories. Again, any required function will be programmable on cnc machining parts. Here are several examples first machine type.
Consider giving any combination of step-by-step instructions. A CNC program is simply another form of instruction set. It’s developed in sentence-like format and also the control will execute it in sequential order, in depth.
An exclusive series of CNC words are utilized to communicate precisely what the machine is intended to do. CNC words begin with letter addresses (like F for feedrate, S for spindle speed, and X, Y & Z for axis motion). When placed together within a logical method, a team of CNC words make up a command that look like a sentence.
For almost any given CNC machine type, there are only about 40-50 words used regularly. When you compare learning to write CNC programs to learning a foreign language having only 50 words, it shouldn’t seem overly hard to learn CNC programming.
The CNC control will interpret a CNC program and activate the combination of commands in sequential order. As it reads this software, the CNC control will activate the proper machine functions, cause axis motion, and in general, refer to the instructions given in the program.
In addition to interpreting the CNC program, the CNC control has a number of 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 confirm the correctness of the CNC program. The CNC control allows certain important operator inputs to become specified outside of this program, like tool length values. Generally speaking, the CNC control allows all functions in the machine to become manipulated.
For easy applications (like drilling holes), the CNC program can be developed manually. That may be, a programmer will sit back to write this software armed simply with pencil, paper, and calculator. Again, for simple applications, this can be the most beneficial method to develop CNC programs.
As applications get more complicated, and particularly when new programs are essential consistently, writing programs manually becomes much more difficult. To simplify the programming process, a personal computer aided manufacturing (CAM) system works extremely well. A CAM method is a software program that runs on your personal computer (commonly a PC) which helps the CNC programmer using the programming process. Generally speaking, a CAM system will take the tediousness and drudgery out of programming.
In lots of companies the CAM system will continue to work with all the computer aided design (CAD) drawing produced by the company’s design engineering department. This eliminates the necessity for redefining the workpiece configuration on the CAM system. The CNC programmer will just specify the machining operations to become performed along with the CAM system can provide the CNC program (much like the manual programmer might have written) automatically.
Once the program is developed (either manually or with a CAM system), it needs to be loaded in to the CNC control. Even though setup person could type this program right into the control, this may be like using the CNC machine as a very expensive typewriter. When the CNC program is developed with the aid of a CAM system, then it is already by means of a text file . In the event the program is written manually, it may be typed into any computer utilizing a common word processor (though many businesses work with a special CNC text editor for this purpose). In either case, this system is as a text file that can be transferred directly into the CNC machine. A distributive numerical control (DNC) technique is used for this purpose.
A DNC technique is nothing more than a personal computer that is networked with a number of CNC machines. Until only recently, rather crude serial communications protocol (RS-232c) needed to be utilized for transferring programs. Newer controls have more current communications capabilities and might be networked in conventional ways (Ethernet, etc.). No matter what methods, the CNC program must naturally be loaded to the CNC machine before it can be run.
As mentioned, CNC has touched just about every element of manufacturing. Many machining processes happen to be improved and enhanced with the use of CNC. Let’s have a look at some of the specific fields and place the increased exposure of the manufacturing processes enhanced by CNC machine usage.
Machining processes which have traditionally been done on conventional machine tools which can be possible (and perhaps improved) with CNC machining centers include a myriad of milling (face milling, contour milling, slot milling, etc.), drilling, tapping, reaming, boring, and counter boring.
In similar fashion, a myriad of turning operations like facing, boring, turning, grooving, knurling, and threading are completed on CNC turning centers.
There are actually a myriad of special “off-shoots” of the two machine types including CNC milling machines, CNC drill and tap centers, and CNC lathes.
Grinding operations of all kinds like outside diameter (OD) grinding and internal diameter (ID) grinding will also be being carried out on CNC grinders. CNC has even exposed a fresh technology with regards to grinding. Contour grinding (grinding a contour within a similar fashion to turning), that has been previously infeasible due to technology constraints has become possible (almost commonplace) with CNC grinders.
In manufacturing terms, fabrication commonly identifies operations that happen to be performed on relatively thin plates. Consider 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, and the sheets are bent (formed) with their final shapes. Again, operations commonly referred to as fabrication operations include shearing, flame or plasma cutting, punching, laser cutting, forming, and welding. Truly, CNC is heavily linked to just about every component of fabrication.
CNC back gages are generally used with shearing machines to manage the size of the plate being sheared. CNC lasers and CNC plasma cutters may also be used to bring plates with their final shapes. CNC turret punch presses is capable of holding a variety of punch-and-die combinations and punch holes in every shapes and forms through plates. CNC press brakes are employed to bend the plates within their final shapes.
Electrical discharge machining (EDM) is the process of removing metal with the use of electrical sparks which burn away the metal. CNC EDM can be purchased in two forms, vertical EDM and Wire EDM. Vertical EDM requires the application of an electrode (commonly machined on the CNC machining center) that may be from the shape of the cavity being machined into the workpiece. Picture the shape of your plastic bottle that must be machined in a mold. Wire EDM is often used to make punch and die combinations for dies sets found in the fabrication industry. EDM is one of the less popular CNC operations as it is so closely associated with making tooling used with other manufacturing processes.
Like the metal removal industry, cnc turning parts are heavily utilized in woodworking shops. Operations include routing (just like milling) and drilling. Many woodworking machining centers are chinbecnnc that may hold several tools and perform several operations in the workpiece being machined.
Many forms of lettering and engraving systems use CNC technology. Waterjet machining utilizes a high pressure water jet stream to slice through plates of material. CNC is even employed in the manufacturing of countless electrical components. For instance, you can find CNC coil winders, and CNC terminal location and soldering machines.
There is quite a shortage of skilled individuals 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 also been my experience that pay scales have not reflected this shortage. Even so, you may make a good wage and establish a rewarding career dealing with CNC machines. Here are one of the job titles of men and women working together with CNC machine tools.