Choosing a plasma cutter can be a daunting task – but not anymore. We lay out a simple and comprehensive guide so that you can learn everything about CNC plasma cutter. We start by educating you about the different components of a CNC machine. When using a CNC plasma cutter, it is essential to know what factors will contribute to a perfect clean cut.
Essential Components of a CNC Machine
Whether you have a high end CNC machine worth a million dollars, or an entry level machine, the following components are essential for every kind of them -
Height controller is an integral part of the CNC plasma cutter machine. The best part of having a CNC machine is automation. You don’t have to work for long hours on cutting a single piece of metal. You just feed the instructions on the CNC control, and it does rest of the job for you.
There are two types of height you should know about – pierce height and cut height. Pierce height is the height of the torch from the metal surface, when you start piercing the metal before actually cutting it. On the other hand, the cut height is the height of the torch nozzle from the metal surface, when it is actually going inside the metal.
The third mode of cutting is the X-Y cutting mode. The cut height was the height while the torch goes up and down. In this mode, the torch moves in horizontal direction instead of vertical.
The primary function of the height controller is to take care of all cut height, X-Y mode and pierce height. If the pierce height is too low, the nozzle and other consumables can get damaged.
It is only because of a quality height controller that you can manage to make thousands of cuts without even spending time with the machine. Just feed in the instructions and come back to a beautifully designed metal.
CNC control which stands for Computer Numeric Control is the brain of a CNC plasma cutter machine. It takes the instructions from the user and monitors motion control and machine control to give precise and decorative cuts. This is achieved by the use of CAD software on the CNC control machine.
It uses the software to monitor height control, drive motors, amperage and other settings. In entry-level CNC machines, the CNC control is done via a PC or laptop. However, in high-end machines, CNC control is done on an exclusively designed robust machine that can stand heavy-duty work environment with all the dirt and electrical noise.
PC and laptops are not suitable to work in such heavy-duty environment. As the electrical noise from other components can distort the information stored on CNC controls. Hence, you should use PCs or laptops only in small-scale shops, or hobbyist projects.
Moreover, you should make sure that your plasma cutter doesn’t use a high frequency starting method. Use a plasma cutter that employs a ‘blowback’ torch starting method. Blowback starting causes less interference which doesn’t damage the CNC configuration on CNC controls.
One important aspect of CNC machines is the user interface. As every small thing on high-end machines is made of a thousand dollars, the user interface is also a thousand steps ahead. These machines have more intuitive and user-friendly design interface than the entry-level CNC controls on PCs or laptops. PCs and laptops demand complex software instructions which further translate into specific instructions for height control and other components. Moreover, one uses the keyboard and the mouse in PCs or laptops, while high-end machines have touch controls.
Another important element is the choice of software. You should use softwares that are exclusively made for CNC machines. Generic software which is made for routers and millers is not that adaptable as the specific software.
Another integral part of the CNC machines is its mechanical components. These components include the rail axis or gantry, the cross axis and the Z-axis. Entry level machines have small and low-cost components that just do the job, while high-end machines have top-notch quality components that are made to work non-stop without any error.
Drive components are essential for the working of the CNC plasma cutter. Think of drive systems as the pedals on a bicycle. They rotate in circular motions to ‘drive’ the bicycle ahead. Similarly, the motors attached on the axis, drive the torch in the required direction.
Entry level machines have stepper motors for the drive system, while high end machines have servo motors. Advanced servo motors have more speed and torque capacity which makes them better than stepper motors. But the fact is that, even stepper motors are equally effective in the entry level segment where there is no heavy-duty work.
Fume Control System
Plasma cutting operations release fumes and gases which have to be absorbed out of the whole environment or they can damage the plasma cutting machine. This is done by using either of the following two types of tables: Downdraft table or water table.
Water tables are less expensive than downdraft tables and have different attributes which may or may not appeal to you. Water tables absorb all the noise and smoke that is produced by plasma cutters. But the dirt gets mixed with water which can lead to poor cuts and torch damage. Downdraft tables have many filters which need to be replaced from time to time. But they are more reliable and produce cleaner cuts. Hence, the latter is preferred by most people.
In short, if you working on light-duty projects and can take care of the water table as and when required, go for the water table. However, if your work goes round the clock and the water table can create the above mentioned problems for you, go for the downdraft table.
CAD and CAM software
CAD stands for Computer Assisted Drawing, and CAM stands for Computer Assisted Machining. Both softwares are essential for entry-level CNC machines. Basically, you draw the electronic sketch of the required shape using the CAD software, then the CAM software converts the sketch into machine instructions for the mechanical components of the plasma cutters. These instructions include kerf width, pierce and cut height etc.
Modern CAM software does much more than simple conversion to machine instructions. It acts as an analyzing tool and computes all the costs, metal waste and productivity. Hence, having a modern CAM software on your machine can do wonders for you.
Now you have a detailed understanding of the different components and their significance.
The best plasma cutter in our review list is the Hypertherm Powermax 45. It offers brand reliability, extraordinary performance and cheap consumables. If you can spend a few hundred dollars more, consider buying the Miller. The Miller has the carry case and the shoulder strap too!
But as budget is the major concern for most people, carry case can be ignored to put the Hypertherm at the number one position. The best plasma cutter had to be good for both industry level and hobbyist projects, and hypertherm proves itself in both fields.
If you’re going to work on a CNC machine, learning about the different components such as CNC control, mechanical components, height control etc. is necessary. Because when it comes to finding the best plasma cutter, knowledge is power!