CNC Plasma Q&A.

Questions and Answers

Q. What are Cnc plasma tables used for? What is Cnc Plasma? What does a Cnc plasma cutter do? What is Cnc plasma? Cnc plasma cutting machine applications?

A. Cnc plasma cutting machines are used to cut metal plates and sheet. They will cut any conductive material with varying results. The ideal application is to cut mild or carbon steel, however great results can be achieved in stainless, and hardened alloy steel such as used in wear plates on earthmoving machines.

Q. How much are Cnc plasma cutters?

A. This is a tricky question because the range of plasma cutting machines is wide and varied. Hobby style machines are often bought from China or through local importers for a few thousand dollars, but their training, performance, longevity and support are atrocious. Many of these run on plastic rollers, driven by rubber belts and stepper motors.

To step up into the area of production quality machines from reputable suppliers with backup and support you will be looking at a minimum of $45,000 (aud) This will get you a solid air plasma machine (not high definition) with training, warranty and support. It is suitable for general fabrication work.

If you require high precision cutting, or extra features like a drilling and tapping head, bevel cutting, advanced fume extraction (follows the torch), dross conveyors to remove slag and fallen parts, then you can expect to pay $150,000 or more for a premium heavy duty industrial high performance Cnc plasma machine with premium fume extraction system, software, training, installation, maintenance and support. Basically, you get what you pay for. It’s not really a cost though, it is an investment that pays for itself many times over through its lifetime.

Q. How accurate is a CNC Plasma cutter?

A. The quality of the Cnc machine and choice of plasma cutter power supply can vary the cut quality and precision dramatically. For instance, a hobby level Cnc plasma table will often be shaky and leave a serrated cut with poor dimensional accuracy. A budget plasma cutter power supply (the torch etc) will leave severe tapers on the cut edges. Any Cnc plasma machine that doesn’t have the optimum settings will cut poorly. On the flip side, a high performance Cnc plasma cutting machine like the HDP PLASMA from ART has everything built into it to achieve the optimum cut quality in material up to 50mm thick (and more for special applications) It can cut very square edges and can switch to special gases to achieve a shiny cut even in stainless steel up to 50mm thick.

The key points to achieving optimum cut quality and precision come down to accurate settings and a high-performance table. ART have partnered with Hypertherm to implement years of cutting parameter development right on the ART machine controller. Only a basic g-code file is required and the ART Cnc controller can automatically apply thousands of settings to the job to achieve the optimal cut. This includes Hypertherm’s patented “True Hole” and “True Bevel” algorithms. Dimensional accuracy can be achieved better than 0.1mm at the surface with minimal taper. Small holes are the biggest challenge for plasma cutting, but Hypertherm’s “True Hole” algorithm built into ART’s controller enables bolt holes down to the thickness of the plate in diameter (1:1 ratio)

Q. Can you make money with a CNC Plasma Cutter?

Yes you can make money WITH a Cnc plasma, but it won’t make the money for you. You need to have a good business model, preferably an existing product or client so that you have work for the machine immediately. Like any machine, it is a very powerful tool that can do amazing things for you, but you have to use that tool correctly and manage your business well to make money.

Q. How does a cnc plasma cutter work? How cnc plasma cutter works? How to operate a cnc plasma cutting machine? How to use a cnc plasma cutter?

 A. A CAD program is used to draw your components. These designs are then imported to a CAM software package that often nests the parts into the available sheet size. It will also add settings that are required to correctly cut the material. The CAM software then creates a file with instructions for the machine to run. This may be transferred to the machine controller over the network or by a USB memory stick. The motion control on the machine allows the operator to set the location of the material sheet or plate. When it is time to run the job, it will go through the instruction one by one and control the axis motors (stepper (yuck!) or servo motors) to make the torch follow the path. A sensing motion is usually performed at the start of each cut to measure the precise height of the material which is never flat. This avoids misfires if piecing too high, and destroying consumables from piercing too low. A special mechanism called a THC (Torch Height Controller) causes the torch to follow the surface of the material precisely after the piece. Variations as small as 0.1mm in torch height can affect cut quality dramatically. The controller turns the plasma arc on and off as required. On superior machines like those from ART, the Plasma Arc on and off is controlled very precisely within milliseconds to achieve round holes and improve other specific features. This causes the current to ramp down before the torch reaches the end of the cut. This also helps to preserve electrode life.

The actual plasma arc is generated by jumping a high voltage electric arc between the material and the electrode through a very small orifice. At the same time various gases are pressurised through the nozzle causing them to ionise. Once the plasma power supply detects the arc has successfully transferred it will then engage a high current dc power supply which transmits along the ionised gas stream into the material. This is a constant current power supply that constantly adjusts the voltage to achieve the current set point. Once the pierce is complete the plasma unit may switch to different gasses to achieve optimum cut quality. If all settings are correct including current, gas selection, pierce height, piece delay, feed rates, motion stability and height control, then you can expect a good quality cut. Of course, if you buy the right machine then all of this is automated, and you don’t need to think about it. Hint… go to  our plasma page

Q. Can a cnc plasma cutter cut aluminum?

A. Yes! Cnc plasma cutters can cut aluminium (aluminum), however you must be aware of special safety considerations. If aluminium is cut on a water table machine, the cutting process consumes oxygen from the water molecules which in turn releases hydrogen. The hydrogen gas can then accumulate under the sheet material and ignite causing a massive explosion.

Cutting aluminium using a dry extraction downgrade table is also a safety concern. This is because mixing iron oxide with aluminium is how you make thermite. Thermite is the cool stuff the military use to burn through steel doors, engine blocks etc. it burns under water and can’t be extinguished (Go on, Google how do I make thermite!) So cutting both steel and aluminium on the same plasma table with dry extraction and filtration can lead to a fire, or worse, an explosion that could burn your factory down. Don’t mess around with this boys and girls! You should thoroughly clean out filters and ducting, and under the machine before switching between the two metals.

Q. How to make a Cnc plasma cutting machine? How to build Cnc plasma table? How to make CNC plasma cutter?

A. If you are really intent on building your own Cnc plasma cutter for hobby purposes then there are many kits available from China and elsewhere. These are barely adequate and don’t support a lot of premium features that are critical for performance and cut quality. Fine for mucking around with.

If you run a business, you may be asking the wrong question. The difference in performance between a home built Cnc plasma machine and an industrial quality machine is huge. It has taken many decades of R&D by large corporations to achieve high-definition cuts that you need for your business. Their data is proprietary and covered by patents, so it Is not accessible to the hobby or diy market. If you are deadly serious about building a machine then our suggestion would be to purchase a Hypertherm Edge Connect controller. This is the quickest way to take advantage of their decades of R&D. We highly recommend purchasing a ready to run Cnc plasma machine that has support, training, installation and warranty if you are running a business.

Q. How to price Cnc plasma cutting work?

A. There are many methods. Some people just use a ”Tonnage Rate“ but this is a terrible idea in our opinion. To do a proper job of quoting you should include cost of material supplied. Beyond that it is common to have a per metre charge for each thickness. Thicker materials use more power, more gas, and take longer to cut. You may also add in a surcharge for each pierce as this is the major cause of consumable wear. Don’t forget to factor in your power and gases in the per meter rate. This can usually be obtained from the plasma torch manufacturer. Never discount your own time either. Once you have calculated the costs you then need to apply your profit margin.

Another factor to consider is the time to load and unload the materials. Time being the computer setting up files should also be added in. Some have a flat rate, but it depends on the quality of the files supplied. Some files have many errors that must be manual corrected, so it may be wise to request sample files from a new customer to verify they can draw correctly. Problems to look out for include gaps at corners, circles that look like octagons, duplicate lines that are sitting on top of each other. These issues can confuse CAM software and result in incomplete or incorrect jobs. Good quality cam software such as ToolShop from ART can detect and repair most of these common mistakes. It also has market to highlight any remaining flaws in the drawing in the case of it not knowing how to repair it. In fact, using software like ToolShop to nest your plasma jobs can be reduced to a few mouse clicks, potential saving you a great deal of time. Cam software is available that can generate a quote based on values you input by analysing the job. This software is generally not in the hobby category.

Q. CNC Plasma Cutting settings?

A. Each material thickness has very unique and sometimes seemingly illogical settings required to achieve the best cut. This is because at certain temperatures the properties of the metal change dramatically. A good CAM package will come pre-loaded with settings for every material type. This is true of ART’s ToolShop Nesting and Toolpathing Software. However, these settings are for a specific plasma torch model and require a machine with good motion performance. Otherwise a great deal of trial and error is required.

ART cnc plasma machines also come with the controller pre-loaded with all the settings required for every material. All that is required on an ART cnc plasma machine is to select the CAD parts (as DXF files) adjust the quantities of each part, tell it the material sheet size, and it will import the files, automatically toolpath the shapes with optimum settings, nest the parts compactly into the sheet (or multiple sheets), adjust the start points and cut order to stop parts moving due to metal expansion, and cut the job. You don’t need to know any settings in this case.

If you buy a quality Hypertherm plasma cutting torch it does come with a set of cut charts for all normal cutting. These will not apply to other brands of plasma cutting torches.

Q. CNC plasma Australia, cnc plasma cutting machine Australia, Where to buy Cnc plasma cutter? What Cnc plasma? Which is the best Cnc plasma table? What Cnc plasma?

A. What do you expect us to say? Of course, we are biased, but we confidently say that ART Cnc plasma machines are a step above anything on the market. ART Cnc plasma machines are highly accurate and can be configured to perform many tasks including bevel cutting, drilling, tapping and machining slots etc. Check out the range here…here…

Q. Easiest Cnc plasma software? How to program Cnc plasma cutter?

A. This is a matter of taste, but we feel that ART’s ToolShop software is extremely easy to use and very powerful. You can import DXF drawings from any Cad program, or you can draw parts directly with the inbuilt CAD module. It has all parameters included for plasma cutting using Hypertherm Powermax, HPR, XPR and MaxPro plasma cutters. It nests the parts optimally into the available material, adds tool path information, can automatically move start points and change cut ordering to avoid part movement, and export a Cnc file ready to cut. And after you have the software set up to your style of drawing it can do all of this with just a few mouse clicks using customised templates. Just select the parts, tell it how many of each and click the button. It’s ready to be sent to the machine.
Contract ART to request an online demonstration of ToolShop