CNC stands for Computer Numerical Control and has been around since the earlier 1970’s. Just before this, it absolutely was called NC, for Numerical Control. (During the early 1970’s computers were introduced to these controls, hence the name change.)
While folks most avenues of life have never heard about this term, CNC has touched just about every method of manufacturing process in one method or another. If you’ll be working in manufacturing, it’s likely that you’ll be working with CNC regularly.
While you can find exceptions to this particular statement, CNC machines typically replace (or work jointly with) some existing manufacturing process/es. Take among the simplest manufacturing processes, drilling holes, for example.
A drill press can naturally be used to machine holes. (It’s likely that most people has seen some sort of drill press, although you may don’t work in manufacturing.) A person might place a drill inside the drill chuck that may be secured from the spindle in the drill press. They may then (manually) find the desired speed for rotation (commonly by switching belt pulleys), and activate the spindle. Chances are they manually pull around the quill lever to get the drill in to the workpiece being machined.
Since you can easily see, there is a lot of manual intervention required try using a drill press to drill holes. One is required to make a move almost every step as you go along! While this manual intervention can be suitable for manufacturing companies if but only a few holes or workpieces must be machined, as quantities grow, so does the chance for fatigue due to tediousness from the operation. And do be aware that we’ve used one of several china machining service operations (drilling) for our example. There are far more complicated machining operations that could call for a greater level of skill (and increase the chance of mistakes causing scrap workpieces) of the person running the typical machine tool. (We commonly refer to the design and style of machine that CNC is replacing as the conventional machine.)
In contrast, the CNC equivalent for the drill press (possibly a CNC machining center or CNC drilling & tapping center) might be developed to perform this operation in a far more automatic fashion. Anything that the drill press operator was doing manually can be done by the CNC machine, including: placing the drill from the spindle, activating the spindle, positioning the workpiece beneath the drill, machining the hole, and turning off the spindle.
There is certainly another article incorporated into 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 a number of products geared towards assisting you learn to use CNC machines. Here we’re relating how CNC works in very general terms.
As you might already have guessed, exactly what an operator would be asked to use conventional machine tools is programmable with CNC machines. After the machine is setup and running, a CNC machine is fairly very easy to keep running. In fact CNC operators usually get quite bored during lengthy production runs as there is so little to complete. With a bit of CNC machines, including the workpiece loading process is automated. (We don’t mean to over-simplify here. CNC operators are normally required to do other things related to the CNC operation like measuring workpieces and making alterations in retain 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 could be linear (along a straight line) or rotary (along a circular path). Among the first specifications that implies a CNC machine’s complexity is when many axes they have. Generally, the greater axes, the greater number of complex the device.
The axes for any CNC machine are required with regards to causing the motions necessary for the manufacturing process. In the drilling example, these (3) axis would position the tool across the hole being machined (in just two 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 can be a, B, and C.
A CNC machine wouldn’t be beneficial if all it could only move the workpiece in several axes. Almost all CNC machines are programmable in numerous other methods. The particular CNC machine type offers quite a bit to do with its appropriate programmable accessories. Again, any required function will be programmable on cnc machining parts. Here are several examples for just one machine type.
Consider giving any number of step-by-step instructions. A CNC program is simply another sort of instruction set. It’s printed in sentence-like format along with the control will execute it in sequential order, step-by-step.
A particular number of CNC words are employed to communicate what the machine is designed 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 in a logical method, a team of CNC words make up a command that look like a sentence.
For any given CNC machine type, there are only about 40-50 words used frequently. So if you compare understanding how to write CNC programs to learning an international language having only 50 words, it shouldn’t seem overly challenging to learn CNC programming.
The CNC control will interpret a CNC program and activate the number of commands in sequential order. As it reads this system, the CNC control will activate the proper machine functions, cause axis motion, as well as in general, refer to the instructions given from the program.
Along with interpreting the CNC program, the CNC control has several other purposes. All current model CNC controls allow programs to become modified (edited) if mistakes are located. The CNC control allows special verification functions (like dry run) to verify the correctness from the CNC program. The CNC control allows certain important operator inputs to be specified separate from this system, like tool length values. On the whole, the CNC control allows all functions from the machine to become manipulated.
For simple applications (like drilling holes), the CNC program could be developed manually. That may be, a programmer will take a seat to create this software armed only with pencil, paper, and calculator. Again, for simple applications, this could be the most beneficial strategy to develop CNC programs.
As applications acquire more complicated, and especially when new programs are required on a regular basis, writing programs manually becomes far more difficult. To simplify the programming process, a personal computer aided manufacturing (CAM) system can be utilized. A CAM product is an application program that runs using a computer (commonly a PC) that assists the CNC programmer with the programming process. Most of the time, a CAM system is going to take the tediousness and drudgery from programming.
In many companies the CAM system will continue to work together with the computer aided design (CAD) drawing created by the company’s design engineering department. This eliminates the requirement for redefining the workpiece configuration towards the CAM system. The CNC programmer will simply specify the machining operations to be performed and also the CAM system will provide the CNC program (much like the manual programmer will have written) automatically.
As soon as the program is developed (either manually or with a CAM system), it needs to be loaded in to the CNC control. Though the setup person could type this software straight into the control, this may be like making use of the CNC machine being a very costly typewriter. When the CNC program is developed with the help of a CAM system, then it is already such as a text file . When the program is written manually, it could be typed into any computer employing a common word processor (though some companies utilize a special CNC text editor for this specific purpose). In any event, this software is such as a text file that can be transferred right into the CNC machine. A distributive numerical control (DNC) system is used for this function.
A DNC technique is simply a personal computer that is certainly networked with a number of CNC machines. Until only recently, rather crude serial communications protocol (RS-232c) needed to be used for transferring programs. Newer controls get more current communications capabilities and can be networked in conventional ways (Ethernet, etc.). Irrespective of methods, the CNC program must naturally be loaded in to the CNC machine prior to it being run.
As stated, CNC has touched virtually every facet of manufacturing. Many machining processes have already been improved and enhanced by making use of CNC. Let’s examine several of the specific fields and set the focus on 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 all kinds of milling (face milling, contour milling, slot milling, etc.), drilling, tapping, reaming, boring, and counter boring.
In similar fashion, all types of turning operations like facing, boring, turning, grooving, knurling, and threading are performed on CNC turning centers.
There are all sorts of special “off-shoots” of those two machine types including CNC milling machines, CNC drill and tap centers, and CNC lathes.
Grinding operations of all types like outside diameter (OD) grinding and internal diameter (ID) grinding may also be being done on CNC grinders. CNC has even showed a new technology with regards to grinding. Contour grinding (grinding a contour inside a similar fashion to turning), that was previously infeasible because of technology constraints has become possible (almost commonplace) with CNC grinders.
In manufacturing terms, fabrication commonly refers to operations which can be performed on relatively thin plates. Think of a metal filing cabinet. All the primary components are made of steel sheets. These sheets are sheared to size, holes are punched in appropriate places, as well as the sheets are bent (formed) with 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 linked to virtually every part of fabrication.
CNC back gages are generally used in combination with shearing machines to regulate the size of the plate being sheared. CNC lasers and CNC plasma cutters are also used to bring plates for their final shapes. CNC turret punch presses can take many different punch-and-die combinations and punch holes in most shapes and forms through plates. CNC press brakes are utilized to bend the plates inside their final shapes.
Electrical discharge machining (EDM) is the procedure of removing metal by using electrical sparks which burn away the metal. CNC EDM is available in two forms, vertical EDM and Wire EDM. Vertical EDM requires the use of an electrode (commonly machined with a CNC machining center) that is certainly in the model of the cavity to be machined in the workpiece. Picture the design of the plastic bottle that must be machined into a mold. Wire EDM is normally used to make punch and die combinations for dies sets employed in the fabrication industry. EDM is probably the less popular CNC operations as it is so closely related to making tooling combined with other manufacturing processes.
As in the metal removal industry, cnc milling parts are heavily utilized in woodworking shops. Operations include routing (comparable to milling) and drilling. Many woodworking machining centers are chinbecnnc that may hold several tools and perform several operations about the workpiece being machined.
Various forms of lettering and engraving systems use CNC technology. Waterjet machining utilizes a high pressure water jet stream to reduce through plates of material. CNC is even utilized in the manufacturing of several electrical components. As an example, you will find CNC coil winders, and CNC terminal location and soldering machines.
There is quite a shortage of skilled people to utilize CNC machines. And the shortage is increasing. 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 really reflected this shortage. Having said that, you can make a good wage and create a rewarding career dealing with CNC machines. Here are one of the job titles of people working together with CNC machine tools.