Getting Automated: Transitioning from hand-held to CNC plasma cutting

Getting Automated: Transitioning from hand-held to CNC plasma cutting

PRACTICAL WELDING TODAY® JULY / AUGUST 2014

July 28, 2014

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Transitioning from the manual plasma cutting process to CNC plasma cutting process might seem like a daunting task. However, if you enter into the process prepared and with the facts, you’ll find that the switch can be relatively painless and one that can help grow your business.

To understand the motivation behind the switch from manual to CNC, you must first outline the factors that might lead you to the decision in the first place. There are four typical reasons that you might want to make the switch: cut quality, cut quantity, cut capacity, and cut complexity.

For some, making the transition from the manual plasma cutting process to a CNC cutting process is a no-brainer. But for others, maybe even you, there’s a hesitation to move forward for one reason or another.

No matter on which side of the fence you find yourself, there are things you need to know that will help you make the best decision for your business. Since CNC plasma cutters come in all sizes and with myriad features, it’s important to take stock of what you need from a machine now and what you think you’ll need from it moving forward. This is particularly important if you have a desire to grow your business.

There are plenty of preconceived ideas out there about what investing in a CNC plasma system entails. Many times those preconceptions are the result of misinformation or ideologies that no longer apply to today’s advanced CNC plasma technology. To make the best decision for your business, you have to know the facts.

Why CNC Plasma?

To understand the motivation behind the switch from manual to CNC, you must first outline the factors that might lead you to the decision in the first place. There are four typical reasons that you might want to make the switch: cut quality, cut quantity, cut capacity, and cut complexity. These factors might be self-imposed requirements, or they might be requirements that are put in place by a customer.

For example, you might pursue work that requires precise and very detailed cuts. Or perhaps you are juggling several jobs at once and you need to increase the number of parts that you produce during a given time frame. Or maybe you are reaching out to new customers who would require you to cut thicker materials.

When the requirements for cut quality, cut quantity, cut capacity, and cut complexity begin to surpass the capabilities of your manual system, that’s when you should start looking into making the investment in an automated system. Mechanized cutting allows you to cut with higher amperages, which allows you to cut a broad range of material thicknesses of 3 inches or more. Some of the present-day precision plasma systems can yield a cut quality that is near that of laser cutting. Additionally, automated CNC motion controls allow you to cut complex shapes with consistent dimensional accuracy and increased part throughput. The end result is more parts per shift and a faster return on investment (ROI).

Cutting Through the Misconceptions

One of the most common misconceptions is that CNC plasma cutting has a steep learning curve to implement and use successfully. In shops where manual plasma cutting is relied upon heavily, it is considered an art form that is learned and crafted after years of experience. These are the same shops that are usually concerned about incorporating PC-based controls in the machine because they are afraid it will take too long to learn how to use them efficiently. That is simply not the case.

True, on the surface it would appear that CNC plasma systems, combined with all of the accessories, are complicated. But all of the system’s components, which can include torch height control, motion control, and the plasma power supply, communicate with one another and work together. The operator just needs to select the material type and material thickness, and then load the part program. From there the CNC communicates with the system’s various components to set and adjust the necessary parameters. In other words, you do not have to be an expert in each component to efficiently and effectively operate a CNC plasma cutting system.

Another common misconception is the length of time it will take to see an ROI. Oftentimes shops shy away from investing in a CNC plasma cutting system because they are intimidated by the price tag and the cost of consumables, and they fear that these costs will lengthen the amount of time for them to realize the ROI.

Consider the big picture. CNCs provide you with the ability to cut a range of materials and thicknesses; they allow you to process material much faster than you can using manual equipment; and they also provide you the ability to cut parts repeatedly and consistently. CNCs also provide you with cut quality that can decrease or downright eliminate secondary processes like drilling and dross removal. This alone saves on your biggest expense—labor.

CNC Plasma FAQs

When shopping around for systems, be prepared by knowing the answers to the following questions.

What am I cutting?

Is it carbon steel, stainless, or aluminum? Some exotic material? Or is it a combination of materials? The type of material is important for many reasons, including whether you’ll require an automatic gas console or a manual gas console. The difference between the two plays into their overall budget.

What is my material thickness range?

Knowing this will help determine the amount of amperage you need from a plasma system. Precision plasma systems come in a variety of amperage ranges and outputs. While one shop might need a system with just a 150-amp maximum output, another shop might need a system that has up to 400 amps. Higher-amperage machines tend to cost significantly more than lower-amperage machines, so knowing what your requirements are might save you from spending more than necessary.

How much floor space do I have?

This might sound trivial, but you need to know how much space you have and if it matches the kind of machine you want.

What is my shop’s power supply?

The electrical power supplied to the building is an important consideration because not all facilities have three-phase power or the right amperage supply. It’s possible that increased power service will have to be supplied to the building if a shop’s amperage is not adequate to carry the load.

What is my budget?

Everyone wants a Corvette®, but not everyone can afford one. CNC plasma systems come in all sizes and capabilities. Some will suit a garage hobbyist and some can accommodate heavy industry fabrication. Some plasma systems are simple 2-axis machines using a consumer-grade PC for motion control, while others have industrial-grade, PC-based controls with built-in drive amplifiers; multiple plasma torches; and drilling, tapping, and beveling capabilities. There’s a CNC system for every budget.

Tips for Long-term Success

Take care of your consumables.

Using the right consumables and providing them with the appropriate care will help them to last a long time, which will cut down on your monthly operating expense. Never get too busy to show love to your consumables!

Stay on top of machine maintenance.

Institute a maintenance program for your machine. It will provide you with many years of service if you take care of it. If you treat your machine well, it will treat you well. The equipment manufacturer will work with you on how best to maintain your machine.

Don’t operate the machine outside of its prescribed capabilities.

Follow the cutting charts that the equipment manufacturer has developed specifically for your machine. Don’t attempt to cut material that is too thick for your amperage range to handle. Doing this can damage the torch, burn through consumables quickly, and damage other components like gas hoses and cables.

Think long term.

One of the biggest mistakes you can make when investing in a CNC plasma cutting machine is to purchase one that accommodates only what you are doing now. After recognizing how much faster production is with the help of a CNC plasma system, it is not uncommon for shops to want to use the machine to grow their business and to pursue new contracts. However, it doesn’t take long for them to find out that the machine they’ve purchased will let them expand only so far.

Talk to an expert about the plans you have for future growth of your business. You will have a better chance of integrating a system that can help you reach your goals if you consult someone who can guide you in the right direction versus going it alone.



Bill Hodges

Product Application Manager for Plasma Solutions
Lincoln Electric
4130 Carolina Commerce Parkway
Ladson, SC 29456
Phone: 800-321-8072

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