When people think of CNC milling, many will only think of one type of machine. Maybe they saw some CNC work in an online video or perhaps they’ve had occasion to use one themselves. The truth, however, is that numerous types of CNC machines exist and each serves a particular purpose.
Computer numerical control is simply the means by which something is made. If a machine can be controlled by a computer and given a specific set of sequences to follow, that machine is capable of CNC. High-tech plasma cutters and 3D printers on a factory floor are just as much CNC machines as the embroidery machine in your local alterations shop. Today, we’re going to tell you about some of the main types of CNC machines in use.
The CNC mill might be the first type of machine to come to mind. Capable of cutting all types of materials, the CNC mill’s primary function is to move its cutters and various other tools to specific locations on a piece of material and then cut that material to a desired depth.
The lathe uses a different technique. While the mill uses coordinates on a plane to determine where it will drill or cut, the lathe spins the material at high speeds while a series of drills, cutters, and other tools make small, precise cuts in it. At the same time, water is pumped onto the cutting surfaces to keep them clean and cool.
Those who took shop in high school may remember using the wood lathe. The CNC lathe is the same concept however the work is done by automated tools and the shape of the finished product has been programmed into the computer. Additionally, CNC lathes are used to cut metals and other alloys – something your wood shop lathe could not begin to touch.
Plasma cutters use the power of physics to cut through metals including steel and any number of alloys. Grade school science always taught us that matter generally has three states; solid, liquid, and gas. There is a fourth state of matter, however, and that is plasma. Plasma occurs when a gas is heated or exposed to strong magnetic fields. This causes a release of electrical energy (usually seen as an arc) which heats the gas to the point that it becomes plasma.
The plasma has two effects. First, it is so hot that it simply melts its way through whatever is being cut. But, because the plasma originated as high-pressure gas, the force of the gas is enough to continuously remove the excess material that is being melted away. This leads to the impression that the plasma is cutting through the material when, in fact, is melting the material and the force of the gas is simply pushing it away from the site of the cut.
Electric discharge machining, or EDM, is similar in that it uses electrical arcs in the process of machining a given part, however, it is electricity and not plasma which shapes the piece being made. Electricity is passed through a special fluid between two electrodes located at various points on the piece of material being machined. As the material is exposed to arc after arc, small pieces of it are removed over time and the finished product begins to take shape.
Finally, we arrive at water jet cutting. The process of using a waterjet involves moving water through a nozzle at such high speed and pressure that it is able to cut its way through metal, rock, or anything else that it comes across. Sand or other abrasives can be added to the water depending on the application of the waterjet but the final product is the same – water is being used to cut through a solid material.
As we mentioned, there are many types of CNC machines in use today in a wide variety of industries. These are only a handful of the many options available to someone seeking to use CNC to manufacture tools, parts, or prototypes.
Our experts are ready to talk to you to determine your needs and put our CNC machines to work for you. Contact us to find out how the CNC mills and machines at Excello Tool Engineering and Manufacturing can machine the highest quality parts and prototypes for you no matter the application.