7 Things To Know About Robotic Welding Systems

Implementing a robotic welding system isn’t something that happens on a whim — at least not successfully. Converting to this technology can help companies gain greater productivity, improve quality and reduce costs in the welding operation, but the process requires thorough planning to gain those results. Working closely with a robotic integrator is a good step to ensure every aspect of the implementation is carefully orchestrated and that the robotic welding system works properly for the given application — in reality, not just theory. Before adding a robotic welding system, it’s helpful to know some key factors that can maximize the return on investment (ROI) in the technology and also help prevent potential problems.

1. Part repeatability is critical to successful automation

The quality of part produced by a robotic welding system depends on the quality of the part that enters the weld cell. That’s why it’s not uncommon to hear the phrase “garbage in, garbage out” when it comes to robotic welding systems — if the part entering the welding cell is flawed, the subsequent weld will be, too.

To protect against poor weld quality, it is critical to have simple, consistent parts that allow the robot to execute the weld in the same location, repeatedly. Having a blueprint or electronic CAD drawing is helpful for confirming that repeatability. Robotic integrators can review the blueprint or they may want to create a software simulation that assesses the suitability of the part for the robotic welding system. After the assessment, they can advise of any adjustments that need to be made prior to implementation.

Proper fixturing is also critical to achieving part repeatability, regardless of whether the application is high volume/low variety or low volume/high variety. Parts that meet the exact specifications can easily be welded incorrectly if they are not held in an exact position during the process. Many robot manufacturers offer vision systems to aid in part recognition and to ensure that the weld path can be altered in real time if part fit-up issues exist. These systems usually work very well, but may cost more.

2. Training is essential

Robotic welding systems require a properly trained operator to oversee them. A skilled welding operator or an individual with previous robotic welding management experience is a good candidate for the job. Again, a trusted robotic integrator is an excellent resource to provide the necessary training, which should cover proper programming, troubleshooting and preventive maintenance. As a best practice, companies should also consider ongoing training support to keep the operator’s knowledge of the system up to date. In many cases, robotic OEMs offer online tutorials, troubleshooting information and/or additional on-site training as aftercare support.

3. Additional safety equipment may be necessary

Many facilities already have fume extraction systems in place for manual welding operations, but converting to a robotic welding system may require additional equipment to help maintain a healthy work environment.  With the increased production brought forth by a robotic welding system, there is also an increase in fume generation. Given the stringent regulations and recommendations from OSHA (Occupational Safety and Health Administration) and other safety regulatory bodies, proper equipment is necessary to maintain compliance.

For larger facilities with higher production robotic welding applications, a centralized fume extraction system is a good option. These systems involve the installation of ductwork throughout the facility and the placement of fume extraction hoods over the welding cell. Smaller shops with fewer robotic welding cells may want to consider a less expensive portable fume extraction system. Operators can wheel these systems right next to the welding cell and adjust the extendable arm toward the robot to suction the fumes. It is also critical that the proper cage and screens are in place around the robotic welding system to protect employees from the welding arc and moving parts within the cell.

4. Weld data monitoring and/or peripherals can help improve results

Adding weld data monitoring capabilities and/or peripherals into a robotic welding system can help improve weld quality and productivity. Achieving these results, however, requires an additional up-front investment.

Weld data monitoring (whether integrated in a power source or via a third party) allows companies to track the parameters of individual welds, determine the cause of weld defects and identify general inefficiencies in order to rectify those problems and optimize the process for peak quality and productivity.  This equipment requires the purchase of software and computers, as well as the establishment and maintenance of an Ethernet network throughout the facility. Companies will also need tech-savvy individuals to review the data and make the necessary adjustments to the robotic welding system according to the data provided.

Similarly, the addition of peripherals — particularly a nozzle cleaning station (also called a reamer or spatter cleaner) can improve weld quality and productivity. By cleaning spatter from the inside of the welding consumables on the front end of the GMAW welding gun, this peripheral helps extend consumable life, reduces downtime for changeover during production and also reduces the cost for replacing consumables. Nozzle cleaning stations also help minimize the loss of shielding gas coverage (due to spatter build-up) that could lead to poor weld quality and rework.

Proper maintenance can help protect the investment in automation

Preventive maintenance of the entire robotic welding system, including the robotic GMAW (gas metal arc welding) gun, consumables and cables is an important step in protecting the investment in this technology. Neglecting maintenance can easily lead to unscheduled downtime, poor quality parts and/or costly repairs. It may even lead to failures that require equipment replacements.

Scheduling time to check connections throughout the system, clean fixturing (to prevent debris that may affect part fit-up) and check TCP (tool center point) helps ensure that the robotic welding system continues to operate within its proper parameters. Certain maintenance can occur in between shifts — cleaning off the robot or changing consumables, for example — while other activities like greasing the robot’s joints may occur less frequently and during a longer scheduled stop. Companies need to assess their individual needs and plan the preventive maintenance schedule accordingly. For larger companies, hiring a maintenance crew to take care of preventive maintenance may be desirable.

6. Communication is key to proper weld quality and cost savings

Retrofitting robotic welding systems is a common practice among many companies, particularly those investing in automation for the first time or for smaller shops requiring only one or two weld cells. It’s significantly less expensive to purchase a used robot than a new one. When retrofitting a robot, however, it is absolutely essential that it is capable of communicating with the selected power source if companies are to have the entire robotic welding system function properly. New power sources feature software that may not be immediately compatible with a robot that is older, or in some cases, the robot may need a specific robotic GMAW gun that isn’t readily available at a welding distributor or possibly even discontinued.

For this reason, it is critical to contact an experienced robotic integrator who can both recommend and help set up all components in the retrofitted robotic welding system. The investment in this assistance can help ensure the proper functioning of the equipment and the long-term cost savings sought by implementing the system. Not to mention, it can also save a lot of frustration and downtime.

7. Robots can do more than just weld

Robots rely on the input of the operator to execute a given task. That task, however, doesn’t have to be limited to just welding or to welding the same part every time. Operators can program the robot to weld multiple parts over the course of a single shift, enhancing the versatility of the robotic welding system and positioning the company to produce additional output. Operators can also program robots to move parts so that a particular unit is not sitting idle when it isn’t tasked with welding; there are components that offer gripping capabilities and can be installed in addition to a welding gun. Companies may even have a tool dock that allows the robot to be fitted with a different tool and proceed with its work.  Some companies with multiple robots may also benefit from installing a vision system in order to check on the work of the others, ensuring that part fit-up is optimal and that the robot is correctly placing welds.

Given that the goal of any robotic welding system is uptime, having the versatility to use a robot for multiple tasks can contribute meaningfully to the other advantages of this technology – increased productivity, improved quality, decreased costs — and may help give companies a real competitive edge.

What You Must Know About Robotic Welding

In the fabrication and manufacturing world, quality and productivity are everything. To remain competitive, companies need to look continually for ways to increase throughput and minimize defects, while also keeping costs low for parts and labor. In many cases, turning to robotic welding is a means to achieve those goals — for both the smaller job shop and larger manufacturing facilities.

The decision to implement a robotic weld cell, however, takes a good deal of consideration and planning if the system is to function in the most efficient, productive and profitable manner. And it requires a significant investment.

Fortunately, the long-term benefits of a robotic welding operation can be very positive. For companies who have already invested in robotic welding, but are looking to improve or better understand their operations, or for those considering the investment, it is critical to consider some key factors about the technology. Here, we will explore “what you must know about robotic welding” to make the most of the process.

1. There’s more to the payback on a robotic welding system than just speed

Justifying the cost of a robotic weld cell comes down to the ability to gain (and prove) a payback on the investment. Typically, that payback comes in the form of greater productivity and higher-quality welds (which minimize instances of costly and time-consuming rework), but there are other contributing factors to the return on the investment (ROI) in this technology. Robotic welding also offers the advantage of lower energy and labor costs, and in many cases lower material costs due to fewer instances of overwelding. Overwelding is a common and costly occurrence in semi-automatic welding. A weld bead that is 1/8-inch larger than necessary can double filler metal costs, but a robot can reduce those costs by only putting down as much material as necessary. Plus, robotic welding systems use bulk filler metals (600-pound drums, for example) that companies can often purchase at a greater discount.                        

For companies just considering the investment in robotic welding, it is important to consider how to calculate the payback. Assess the current part cycle times and compare those to the potential cycle times of a robot. A trusted robotic welding integrator or OEM can often help with this calculation. During this process, also consider the possibility of reallocating existing labor to other parts of the welding operation, where these individuals can add value to the process. Remember, up to 75 percent of the cost in a semi-automatic welding operation is labor. If there is the opportunity to use that labor elsewhere to increase part production, the payback on the investment in robotic welding will increase.           

Most companies — particularly smaller ones or those with frequent production changes — seek a payback on the robotic welding investment of no greater than 12 to 15 months. That time frame is entirely possible to achieve with proper up-front planning of the part blueprints, fixturing and general setup of the system. In some cases, companies may be able to justify a longer payback period if they know that their production needs will remain relatively static for longer periods of time.

2. Parts and product flow need to be consistent

The output from a robotic welding cell is only as good as the parts fed into it. In order to gain the advantages of these systems, it is critical to have accurate, repeatable part designs. Gaps, poor fit-up or poor joint access all prevent a robot from completing its job correctly.

The best part designs for a robotic welding application are simple ones that allow the robot to execute the same weld repeatedly. High-volume applications with low-variety parts are especially poised to gain the advantages of robotic welding. Companies should try to avoid part designs that require intricate tooling or clamping to hold it in place, as both can hinder the efficiency of the robot and also add to the up-front cost of the operation. That said, in some cases, companies may still be able to gain a good payback on the investment in tooling for slightly more complex parts, but they will need to weigh out the pros and cons of that cost ahead of time.

Companies also need to be certain to assess their overall welding operation for consistent process flow. Bottlenecks upstream can easily slow down the movement of parts into the robotic work cell and the ability of the system to function to its full capacity. A robot that sits idle costs time and money. Some companies may need to reconfigure operations or set up a flexible cell that can manage quick tool and fixture changes in order to minimize bottlenecks in the process flow. It is also important to have adequate labor to supply the robot with parts.

Again, companies should consider tapping the knowledge of a robotic welding integrator for advice and assistance to optimize process flow.

3. The MIG guns and consumables on the robot can impact productivity and profitability

The robotic MIG gun and consumables on a robot together are responsible for directing the current to the arc to complete the weld, making them integral components in the whole system. To gain the best quality and to avoid expensive downtime for maintenance, repairs or replacement, companies need to select a robotic MIG gun that is suitable for the amperage, duty cycle and cooling capacity needed in the application. Using a robotic MIG gun that offers inadequate cooling or amperage can cause performance issues and lead to premature failure — both factors that increase costs and downtime. Likewise, using a robotic MIG gun that offers higher amperages than necessary raises the total cost of ownership, as typically the cost of a robotic MIG gun increases directly in proportion to its amperage.

Companies also need to select their consumables — contact tips, nozzles, retaining heads (diffusers) and liners — carefully and manage them properly in order to gain optimal productivity and lower costs.

Look for contact tips with more mass at the front end and that are buried further in the gas diffuser — both features help the tip resist heat from the arc. Consumables with tapered connections mate securely together to provide good electrical conductivity, which also reduces heat buildup and helps the consumables last longer.

Contact tips with long tails and coarse threads are also a good option to simplify installation — they virtually eliminate cross-threading because the tail concentrically aligns the contact tip within the diffuser before the threads engage. This easy-to-install design works well for operations with less experienced welding operators who may not be as familiar with consumable changeovers. It also helps reduce unplanned downtime for troubleshooting associated with cross-threading.      

As with robotic MIG guns, carefully matching the type of consumables to the application can keep companies from having to address premature failures and/or accrue costly downtime (not to mention, lapses in production). It can also keep them from overpaying for consumables that may be too much for the application.

Companies should also consider the mode of welding when selecting consumables, as technology such as Pulsed welding tends to be especially harsh on consumables and often requires heavy-duty options to withstand the heat of the arc for longer periods of time. For these applications, look for contact tips that are engineered with a hardened insert, making them more resistant to arc erosion and wear. They typically last 10 times longer than copper or chrome zirconium tips. Companies can regain as much as 95% of lost productivity for contact tip changes with this style by reducing planned downtime for the task.

4. Peripherals can help improve the return on investment in a robotic welding operation

Peripherals refer to any additional equipment integrated into the robotic welding system to maximize its performance. They include items such as a nozzle cleaning station (sometimes called a reamer or spatter cleaner), anti-spatter sprayers, wire cutters and neck alignment tools. Unfortunately, some companies downplay the value of peripherals, viewing them as an unnecessary cost, and don’t realize that they can play an important role in reducing downtime and rework, improving quality and increasing productivity.

Consider a nozzle cleaning station, for example. As its name implies, this peripheral cleans the nozzle of dirt, debris and spatter, typically during routine pauses in the robotic welding operation. This cleaning action helps prevent shielding gas coverage loss that could lead to weld defects, expensive rework and lost productivity. The equipment also helps the front-end consumables last longer — and longer consumable life means less downtime for changeover and less expense for replacements. The addition of an anti-spatter sprayer further improves consumable life and performance by adding an anti-spatter compound that serves as a protective barrier against spatter buildup and other contaminants.

In the long run, the up-front investment in peripherals such as these can lead to measurable savings and provide a better return on investment by aiding the robot in doing what it does best: complete consistent, high-quality welds for longer periods of time than a semi-automatic welding operation. 

5. Having skilled operators with proper training to oversee the robotic weld cell is critical

Robotic welding operations require ongoing supervision and maintenance, and that job needs to be completed by a skilled operator who has undergone the proper training. When considering an investment in robotic welding, companies should take care to evaluate the available pool of talent. As a rule, skilled welding operators and/or employees with prior robotic welding experience are the best candidates to supervise the weld cell.  After the proper training, which a robotic integrator or OEM can typically provide, these employees can provide the necessary operating and troubleshooting skills to ensure the maximum uptime in the robotic welding cell.

As part of the routine training, it is absolutely necessary for the operators who will be overseeing the robot to be able to schedule and perform routine preventive maintenance on the system. Implementing preventive maintenance helps minimize unnecessary downtime and keep the robotic welding system running more smoothly. If problems can be solved before they arise and the robotic welding equipment made to last longer, it can protect the company’s investment, and ensure the productivity and profitability sought by this equipment in the first place.

Companies should consider vetting robotic welding integrators to determine the availability and costs associated with the training of personnel. Typically training lasts one to three weeks, depending on the certification level desired, and continuing tutorials are often available.

In the end, careful planning, good equipment selection and proper training are all “must-knows” for managing a profitable and productive robotic welding operation. So whether a company is new to robotic welding or trying to improve an existing operation, knowing some key factors can go a long way in helping to gain a competitive edge and to make the most out of the investment.

FAQs About Robotic Peripherals Answered

Automated welding systems add speed, accuracy and repeatability to the welding operation. They can help operations increase productivity and reduce costs in a relatively short period of time. But these results don’t happen by accident; they require careful equipment selection, system integration and training — including the selection of peripherals.

Peripherals refer to the additional equipment that is integrated into the automated welding system to maximize its performance. The selection and implementation of the proper peripherals should be a part of the welding automation plan upfront, not later after the system is in place. Incorporating peripherals early in the process can result in more efficient throughput, long-term cost savings, better quality welds and minimized downtime.

Consider these frequently asked questions about peripherals to clarify their role in the welding operation and better understand their benefits.

Why is a nozzle cleaning station important?

A nozzle cleaning station (also called a reamer) cleans spatter from the inside of the welding consumables on the front-end of the MIG welding gun, including nozzles, contact tips and retaining heads.

There are several benefits a nozzle cleaning station can offer. First, by keeping the nozzle clean, this equipment helps reduce the risk of losing shielding gas coverage that could potentially lead to expensive re-work. Secondly, it helps lengthen the life of the consumables (nozzle, contact tip and diffuser or retaining head) and the robotic MIG gun. Longer equipment life translates into less downtime and also less cost for equipment — both factors that contribute positively to a company’s ROI of its automated welding system.

What’s the benefit of adding an anti-spatter sprayer to a nozzle cleaning station?

An anti-spatter compound (typically in liquid form) can provide additional protection to consumables. A sprayer applies the anti-spatter compound to the front-end consumables after they have been cleaned. In many cases the sprayer can be mounted on the nozzle cleaning station, integrating it into the overall process of nozzle cleaning.

Recall that the rule of “less is more” applies. Excessive anti-spatter usage can lead to unnecessary costs and the compound may build up on the nozzle, the welding robot and the parts being welded. In the long term, a high spray volume could cause additional problems that are just as harmful as spatter build-up itself.

How can a wire cutter help the operation?

Many robotic welding applications require consistent welding wire stick-out (also called electrode extension) when the arc initiates. A wire cutter can help maintain that consistency.  

As its name implies, a wire cutter cuts the welding wire to a specified length and it also removes any inconsistencies at the end of the wire, resulting in more reliable and smoother arc starts. For companies that program their robot to seam track (or find the joint) through touch sensing, the consistent wire stick-out allows for more reliable and repeatable welds by helping the robot to more easily locate the correct spot to begin welding.

Most wire cutters are capable of cutting different types of welding wire, including stainless steel, flux-cored and metal-cored, usually up to 1/16-inch diameter. Companies may prefer to mount the wire cutter on a nozzle station or locate it remotely, according to their needs.??

How do neck inspection fixtures work?

This peripheral verifies that the robotic MIG gun’s neck is set to the intended tool center point (TCP), allowing it to be readjusted after a collision or if the neck becomes bent due to routine welding. Most inspection fixtures will accommodate standard necks for a particular brand of robotic gun.

After determining the tolerances for the program, a trained welding operator simply adjusts the neck to meet the correct specifications. This adjustment helps prevent costly rework due to missing weld joints and can help prevent the downtime to reprogram the robot to meet the welding specifications with the existing bent neck. For companies that maintain a large number of robots, a neck inspection fixture can also help prevent confusion when exchanging necks from one robotic MIG gun to another. Welding operators simply remove a bent neck, exchange it with a spare that has already been inspected and adjusted, and put the robot back in service immediately. The damaged neck can then be set aside for inspection while the robot is still online.

How can peripherals help protect against collisions?

In cases where collision detection is integral to the robot, a solid arm mount can help protect against a collision. As its name implies, a solid arm mount is just that: solid. It does not provide electrical feedback during an impact, but rather relies on the software to stop the robot during an impact.

For robots without collision detection, a clutch may be added to the system. The function of a clutch is both mechanical and electrical. It recognizes the physical impact of the collision and then sends an electrical signal back to the robot controller, causing the system to stop. This action prevents damage to the robot and the robotic gun. It also alerts the welding operator overseeing the operation that there is an incorrect variable in the weld cell.Both clutches and solid arm mounts require mounting arms to attach them to the robotic MIG gun and hold it in a specified position, so the robot can repeat the same weld throughout the welding process. These mounting arms are generally composed of a durable aluminum alloy that can resist breakage during an impact.                                                                                                            

Although the addition of peripherals to an automated system does add to the initial cost of automating, this equipment can lead to measurable savings in the long term. Since the goal in automated welding is repeatability and increased productivity, any additional equipment that can help achieve that result is worth the consideration.

From the Contact Tip to the Robot: Answers to Frequently Asked Questions About Welding Automation

Robotic welding systems, when implemented properly and for the right application, can add great value to a welding operation. In addition to offering faster speeds and greater productivity, robotic welding systems can improve weld cosmetics, reduce rework and repairs, lower materials costs by limiting overwelding and also reduce labor costs. The consistency of these systems and the typically rapid return on investment (ROI) make them especially appealing for companies looking to gain a competitive edge. 

Still, setting up a robot and selecting its components — the consumables and the gun, for example — can be a complicated business, especially for first-time users. In fact, the simple question of whether to automate may itself be confusing to a company that hasn’t used a robotic welding system before.

For insight into welding automation, consider these answers to some of the most frequently asked questions. 

What are the best applications for a robotic welding system?

High-volume, low-variety applications are well-suited to robotic welding; however, lower-volume, higher-variety applications may also work if implemented with the proper tooling. Companies will need to consider the additional cost for tooling to determine if the robotic welding system can still provide a solid return on the initial investment.

In either case, it is critical that the application have simple, consistent parts so that the robot can repeatedly execute the weld in the same location. Having a blueprint or electronic CAD drawing is helpful. Robotic integrators can review the blueprint or create a software simulation that can assess the suitability of the part for welding automation. These assessments can not only help to visualize the quality of the part to be welded, but they can also identify ways to fine-tune tooling to optimize the process. Workflow is also important. Companies should be certain to have a high enough flow of parts to the robotic welding cell for the application so that it can operate consistently. Delays in upstream parts fabrication can cause bottlenecks that result in costly downtime.

Is it better to use fixed automation or a robot?

Each type of automation has its own best applications. Fixed automation is an efficient and cost-effective way to weld simple repetitive straight welds or round welds, where the part is rotated. It is good for high volume applications of a single part. Fixturing for fixed automation can be expensive. Companies will need to factor that cost into the initial investment and determine whether this type of automation is still cost-effective for the long-term. They also need to determine if future jobs will require retooling, as that will add further to costs. 

For companies wishing to have the flexibility to weld on multiple applications, a robotic welding system is a better choice. Because a robot can be programmed for multiple jobs, it can often handle the task of many fixed-automation systems.

Who is the best candidate to operate a robotic welding system?

Robotic welding systems require a trained operator. Skilled welding operators or those with previous robotic welding management experience are good candidates. The person overseeing the robotic welding system should be able to program it, troubleshoot errors and perform preventive maintenance. Robotic OEM manufacturers can often provide the appropriate training for employees who are new to welding automation. It is recommended to look for ongoing training support. Some robotic integrators or welding solutions providers offer online tutorials, troubleshooting information and/or additional on-site training as part of their aftercare support.

Can an air-cooled robotic MIG gun be used instead of a water-cooled gun?

In many cases, yes. However, it is necessary to ensure that the air-cooled robotic MIG gun is rated at a high enough amperage and duty cycle for the application. For example, consider an air-cooled robotic GMAW gun rated at 500 amps with 60 percent duty cycle. It is using mixed gases will be capable of welding continuously for 6 minutes (out of an available 10 minutes) at about 350 amps. When welding with pulsed waveforms, it is very important to review the peak currents. Ensure the currents do not exceed 350 amps at any time during the welding process.

Air-cooled MIG guns offer the advantage of being less expensive, both to purchase and maintain. If a company anticipates longer periods of welding or higher amperage needs, it may be necessary to shift toward a water-cooled gun. There are also “hybrid” robotic MIG guns available in the marketplace. These guns feature a durable neck similar to an air-cooled MIG gun, but offer the higher cooling capacity of a water-cooled model by way of exterior water lines. These guns can be easier to maintain than a standard water-cooled MIG gun. They typically offer 300 to 550 amperage welding capacity at 60 percent duty cycle (using mixed gases). At these levels, they are adequate to weld on a variety of applications.

What are the best consumables to use?

The style of consumables — contact tips, diffusers (or retaining heads) and nozzles — depends entirely on the application. Ideally, the consumables should be durable enough to last the duration of a robotic welding shift to help minimize downtime for changeover. High-amperage applications (over 300 amps) with high levels of arc-on time can often benefit from heavy-duty consumables. Chrome zirconium products are a good choice. For lower amperage applications or applications with short arc times, standard-duty consumables (often copper) are appropriate.

Companies also need to consider the access required to reach the weld joint. In some cases, it may be necessary to use a bottleneck, straight or tapered nozzle, all of which are narrower, to maneuver around tooling or into complex areas.     

It is equally important to consider the mode of welding being used. For example, pulsed welding programs can be especially harsh on consumables due to the higher levels of heat that the process generates. These applications can benefit, often, from heavier-duty consumables.

What is the benefit of touch sensing?

Touch sensing, sometimes called joint touch sensing, is a software system that employs the welding wire or nozzle to help locate the joint in a robotic welding application. This software allows the robot to store position data and send electrical impulses back to the controller once it has located the joint. For applications that have slight variations in parts, touch sensing helps maintain weld consistency. It is also more cost-effective than investing in new tooling and fixturing to hold a part in a precise location; if the part moves slightly, the robot can still locate the joint and weld accurately if the joint has well-defined edges. Touch sensing does add a few seconds to the cycle time. However, it is a good choice especially for companies welding large, thicker parts that would be costly to rework should the joint be welded poorly.

To gain optimal results, it is a good idea to combine touch sensing with a robotic MIG gun that has a wire brake feature. The wire brake holds the welding wire in a set position while the robot articulates and searches for the weld joint, ensuring more accurate touch sensing readings. ?

Is it necessary to add peripherals to a robotic welding system?

It is always advisable to add peripherals. Particularly a nozzle cleaning station (also called a reamer or spatter cleaner), to a robotic welding system. This peripheral cleans spatter from the inside of the welding consumables on the front end of the MIG welding gun. This includes nozzles, contact tips and retaining heads. It helps extend consumable life, and with that, reduces downtime for changeover during production. Along with reducing the cost for replacing consumables. Nozzle cleaning stations also help reduce the risk of losing shielding gas coverage (due to spatter build-up) that could potentially lead to expensive re-work.

Adding a sprayer provides additional benefits, too. This peripheral can be mounted on the nozzle cleaning station and works by applying an anti-spatter compound. The compound is applied to the front-end consumables after they have been cleaned. This compound coats the inside and outside of the nozzle, and also the contact tip. As a result, this creates a protective barrier between the consumables and spatter.

What type of payback can be expected from a robotic welding system?

The payback on a robotic welding system can be relatively quick in many cases. To determine it, companies need to assess their parts volume, as well as the amount of time it takes to weld those parts manually, and compare that information to the potential cycle times of a robotic welding system. Determining this volume is critical, given that labor comprises 75 percent of the cost of a manually welded component. Even if a company produces the same amount of parts, labor could be reallocated elsewhere to increase productivity and enhance the payback on the robotic welding system.

Companies should also calculate the savings for overwelding often associated with semi-automatic welding applications. A weld bead that is 1/8-in. larger than necessary can often double filler metal costs. Because robots are more precise in their placement, companies should calculate the potential savings for filler metals when calculating payback. Because robotic welding systems use bulk filler metal drums that require fewer changeovers (and sometimes have the perk of bulk purchasing discounts), that savings can also be considered.

As always, when companies encounter problems with a robotic welding system or have questions about a program or component, it’s best to contact a trusted robotic integrator, welding distributor or welding equipment manufacturer for support. Robotic welding systems aren’t cheap and companies should never take chances with their investment by guessing about the right course of action. The right information is the best way to gain productivity, quality and cost improvements from a robotic welding system.

Don’t Let Your Gun and Consumables Get in the Way of Your Welds

A Guide to Troubleshooting Common GMAW Gun and Consumable Problems

Making a high-quality MIG weld is no easy task. But making a high-quality weld when your MIG gun and welding consumables aren’t functioning properly is just about impossible. Porosity, excessive spatter, undercut and burn back are just a few of the problems that can occur when something’s not right with these components. Troubleshooting weld defects can be a difficult task, since any single problem can be caused by a variety of factors.

It is often easier to avoid weld defects from occurring by conducting a thorough check of your MIG gun and consumables prior to welding than it is to troubleshoot an existing issue. Problems will inevitably occur, but being able to quickly and accurately identify their source will save you money and frustration.

The following is a guide to solving many of the most common consumables and gun-related problems associated with MIG welding.

Wire Does Not Feed

There are a number of problems that could cause the wire to not feed, including issues related to the feeder relay, control lead, adapter connection, liner or the trigger switch.

Begin troubleshooting this problem by checking whether the drive rolls are turning when the gun trigger is pulled. If they are not turning, an electrical continuity failure is occurring. Check the terminals and connector contact pins to ensure the gun is properly connected to the wire feeder. The wire can also fail to feed if the trigger switch is broken, or control leads in the gun cable are damaged. If this is the case, they will need to be replaced.

If the drive rolls are turning but the wire is not feeding, it is usually caused by inadequate drive roll pressure or a blockage in the contact tip or liner. Check the drive rolls and contact tip before moving on to the liner, which takes more time and effort to check and replace.

If a faulty feeder relay is the cause, consult the feeder manufacturer for information on correcting the problem. A broken control lead or a poor adapter connection will require you to test and replace the leads and/or contact pins. Some guns feature a spare set of control leads that can be used to correct the problem. With others, it may be necessary to replace the entire cable.

Contact Tip Burnback

Burnbacks can be caused by improper equipment set-up, including incorrectly installed consumables. Look for easy-to-install contact tips, such as those with coarse threads that require only a quick turn to be properly seated. Be sure to check the following factors if you experience an increase in your contact tip burn back rates.

Improper tip recess and improper wire stick out can cause increased burnback frequency. In the case of incorrect tip recess (or stick out), you will need to install a nozzle and tip combination with a different recess. Similarly, adjusting the distance between the gun and the workpiece (tip-to-work distance) will resolve burnback problems associated with wire stick out.

A faulty work lead/ground is another possible cause of burnback. Check and possibly replace the electrical connections and cables to ensure a faulty work lead/ground will not cause any further burnback.

Erratic wire feeding, a problem with several possible causes, is a frequent source of burnback. See the section below for information on correcting erratic wire feeding.

Erratic wire feeding

Erratic wire feeding simply means that the wire is not feeding from the gun at a consistent rate. This problem is usually caused by the liner, the drive rolls or the contact tip.

A worn out or kinked liner, or build-up of debris, filings, dirt and other foreign material inside the welding liner, the wrong size liner and misalignments or gaps at the liner junctions caused by an improperly trimmed liner can all cause the wire to feed erratically. In each case, the liner will likely need to be replaced and properly trimmed so that it fits as tight as possible to the other components. Some liners require no measuring for error-proof installation. After being loaded through the neck of the gun, these liners are locked in place and concentrically aligned with the gas diffuser and the power pin. This creates a perfectly aligned and gap-free wire feed path for improved wire feeding.

Improper Drive Roll Size & Tension

Improper drive roll size, worn out drive rolls and improper drive roll tension are also potential causes of erratic wire feeding. Replace worn out drive rolls or those of the wrong size with correctly sized and tensioned drive rolls.

Another common cause of erratic wire feeding is a contact tip that is worn out or the wrong size for the wire being used. If you suspect the contact tip is causing the wire to feed erratically, it is best to replace the tip. To extend contact tip life and reduce the risk of erratic wire feeding, look for a consumable system that locks and aligns the contact tip to the liner. This helps ensure the wire feeds smoothly through the tip and reduces internal wear, friction and heat.

Short contact tip life

Although quality plays a critical role in contact tip service life, tip life can vary dramatically from application to application. It is difficult to give an average longevity to expect from your tips. If you notice a change in your contact tip life from their normal life spans, however, check the following factors as necessary.

Using the wrong size contact tip, exposure to excessive heat or erosion caused by the wire are all contributing causes to premature contact tip degradation.

If your contact tip is melting due to excessive heat, it is likely a result of exceeding the product’s rated amperage or duty cycle, in which case you should replace either the tip or the tip and the MIG gun with heavy-duty equipment. You can also reduce heat exposure with a contact tip that is buried further into the diffuser. It is not only protected from the heat, but also cooled by the shielding gas. Also, look for tapered consumable designs that lock conductive parts, including the contact tip together. These help minimize electrical resistance and heat buildup that could shorten contact tip life. Locking conductive parts together provides concentricity that helps prevent keyholing (or uneven contact tip wear) that can reduce the overall life of the contact tip.

If the wire is prematurely wearing out the contact tip, the drive rolls may be creating small burrs on the wire that can erode the inside of the contact tip. Setting the drive roll tension too high can also create deformities in the wire that cause it to mechanically wear out the tip, which is especially common with knurled drive rolls. If this is the case, the drive rolls will need to be properly tensioned or replaced.

Other Causes of Short Contact Tip Life

Gaps and misalignments along the feed path within the gun may also result in the wire wearing away the contact tip from the inside leading to a burnback or premature keyholing. Ensure that your MIG gun liner has been trimmed to the correct length during replacement, or use a consumables system that ensures accurate liner length without measuring to prevent these issues.

The wire can also cause premature contact tip failure if it is rusty, dirty or simply a low quality wire with excessive imperfections. If this is the case, the wire needs to be replaced.

Erratic Arc

If not caused by erratic wire feeding, the most common cause of an erratic arc is usually inconsistent electrical conductivity. If the contact tip is either too big to begin with or worn out from use, it can fail to consistently conduct electricity to the wire and thereby cause an erratic arc. In either situation, the contact tip should be replaced with a new one that is the correct size.

If the gun neck being used is too straight, it could produce an erratic arc through a lack of conductivity. The bend in the neck increases electrical conductivity by creating a continuous contact point as the wire is guided along the outside of the bend in the liner and through the tip. An erratic arc caused by an insufficient bend angle needs to be addressed through the installation of a neck with a 45-or 60-degree bend. Another possible cause of an erratic arc is a worn or kinked liner, a liner trimmed incorrectly, or build-up inside the liner. This should be resolved by replacing the liner, trimming it to the correct length and checking the condition of the wire to ensure there are no inconsistencies that will cause the problem to recur.

Also be sure to check the work lead/ground clamp and gun connections to ensure a good electrical circuit is established.

Extreme Spatter

From a gun and consumables perspective, improper tip installation and improper weld puddle protection are two common causes of excessive spatter (see photo). First check to make sure the tip is installed properly and that it is at the correct recess for the application.

Next, verify that the correct shielding gas is being used and that the weld is receiving adequate shielding gas coverage. Too little or too much shielding gas can both cause poor weld puddle protection and lead to excessive spatter. Clogged nozzle and diffuser orifices could cause too little shielding gas flow, so check and clean or replace the nozzle and diffuser as necessary.

Additional non-equipment-related causes of excessive spatter can be incorrect electrical parameters or a contaminated work piece. Verify that the voltage and wire feed speed are at the recommended levels for the application and that the work piece is free of rust, mill scale and other contaminants.

Some welding factors, such as the short circuit process, using pure CO2 gas and galvanized metal have inherently higher spatter rates, which can be mitigated through using an Argon rich gas blend or a different filler metal transfer process.

Porosity In Weld

Porosity, which are holes in the weld bead caused by trapped contaminants and gasses can have many causes (see photo). Exposure of the weld puddle to atmospheric air, whether as a result of plugged gas ports, a ruptured gas hose, too much or too little gas flow, or a faulty solenoid, is one of the most common causes of porosity. Ensure proper gas flow before moving on to diagnose other possible causes of porosity.

Worn out or damaged parts, including the diffuser, the insulator, o-rings and fittings can all lead to compromised gas coverage. Check each of these components and replace as necessary. Further causes of porosity include excessive wind in the welding environment blowing away the shielding gas. You will need to either move to a less windy site or set up screens to block the wind.

Gun Running Hot

If your gun is getting too hot, it is most likely because you are either exceeding its rated amperage or duty cycle, or else loose power connections or a degraded power cable are causing excessive resistance in the weld power circuit. If you exceed the gun’s duty cycle, you can either decrease the parameters to within the gun’s rating, or use a higher rated gun.

If loose connections are causing the problem, clean and tighten connections that are in good working condition or replace ones that are worn out. One common symptom of loose power connections or a degraded power cable is a discolored liner (see photo). The discoloration is caused by heat and indicates that weld current is being carried through the liner instead of the gun’s power cable. Also check to make sure the work lead/grounding connection is tight and free of obstruction.

Although it’s clear from the above problems that there are many ways that your MIG guns and consumables can lead to poor weld quality, the good news is that most problems usually have simple and inexpensive solutions. By following these recommendations, you will be able to address and resolve the vast majority of the most frequently encountered welding problems.

For more information on troubleshooting specific welding problems, contact your nearest welding distributor or the customer service department at the equipment manufacturer.

Good GMAW Welds Begin with Good, Well-Maintained Equipment

It might at times seem like alchemy, but in fact there is nothing mysterious or magical about making a good GMAW weld. A good weld is the result of properly functioning equipment, good technique and the correct equipment settings for the application at hand. Like a tripod, if any of these three elements are not in place, the result will almost certainly be a poor weld.

On the equipment side, the MIG gun and consumables are often overlooked as a critical element in the process of producing a high quality weld. However, being the most handled pieces of equipment and the closest to the point of the arc, the gun and consumables are exposed to continual mechanical and heat stress.

Two critical elements to ensure the gun and consumables do not interfere with your ability to produce high quality GMAW welds are proper gun maintenance and correctly troubleshooting problems when they arise.

Maintaining Your Equipment

Thankfully, GMAW guns and consumables don’t require a lot of time consuming maintenance and upkeep. Nevertheless, failing to spend a small amount of time maintaining your equipment could result in spending a significant amount of time reworking bad welds.

The majority of gun and consumables maintenance simply involves checking the visible components of the equipment for problems. This includes for looking loose fittings, damaged cables, clogged diffuser ports and the like.

Below is a component-by-component guide to minimize downtime for reworking bad welds.

Feeder Connection — The feeder connection, which carries the electrical current and gas from the wire feeder to the gun, should be tight fitting and free of excessive dirt and debris. The O-rings that ensure the shielding gas flows into the gun cable and nowhere else, should be in good working order, ie: not dry, cracked or otherwise damaged.

If the feeder connection is loose and cannot be properly tightened, it will likely need to be replaced. The same goes for damaged O-rings. A dirty direct plug usually can be cleaned with an electrical contact cleaner.

Cable — Cable maintenance involves little more than inspecting it on a daily basis to ensure there are no cuts, kinks or other damage that could interfere with weld quality and also cause a safety hazard.

Avoid problems such as porosity, an erratic arc and damage to the copper cable stranding by keeping the cable from bending at too severe of an angle.

Liner — Accessing the liner can be very time consuming, so you should limit routine maintenance activity to periods when the liner is easily reached, such as during wire changeovers or when the gun is disconnected from the feeder. You can clear out any built up debris, including metal filings from the welding wire, by using compressed air during these changeover times.

Handle and Trigger —Daily visual inspection should be conducted to ensure there are no missing screws or other damage to the handle and that the trigger is not malfunctioning. These items should be replaced as necessary if they are found to be damaged.

Neck — The neck connections, and the insulators that separate electrically live components from neutral components, should be checked on a regular basis as both a safety and weld quality measure.

Loose neck connections should be tightened or, if damaged, replaced. You should also check that the insulators are in place at either end of the neck and that they are undamaged.

Consumables — Consisting of the diffuser, nozzle and contact tip, the consumables require regular replacement simply by virtue of their role in the welding process and proximity to the arc. Extending the life of the consumables is relatively easy, however, and you can save a significant amount of downtime and equipment costs through some simple maintenance steps.

Multiple times daily, use a welding pliers or reamer to clear out any spatter or other debris that could clog the nozzle and diffuser, being careful not to damage these parts in the process.

Also, you should check the O-rings on the diffuser, the connections between the diffuser, neck and contact tip, the nozzle insulator and the contact tip on a daily basis. Loose connections can usually be tightened, but you should replace these components if any other types of damage appear.

Troubleshooting

Of course, no amount of preventive maintenance will be able to stop every problem from occurring. So, when a problem does arise, it’s important to be able to identify and correct its cause.

Often, the same problem, such as erratic wire feeding, can have more than one cause. In these cases, it’s usually a good idea to conduct the troubleshooting effort by working from the easiest component to check to the most difficult.

For example, both the liner and the contact tip can be the source of erratic wire feeding. The liner takes approximately 20 times longer that the contact tip to check, so it makes sense to begin with the contact tip and only check the liner if necessary.

Below are a few of the most common problems that occur as a result of gun and consumables malfunction.

Wire does not feed — If your wire is not feeding at all, it is most likely being caused by a faulty feeder relay, control lead, adapter connection, liner or trigger switch.

If the drive rolls are not turning when the gun trigger is pulled, it is either because an electrical continuity failure is occurring at the gun connection or the trigger is not functioning properly. Repair or replace any of these items discovered to be the cause of the problem.

If the drive rolls turn, but the wire is not feeding, there may be inadequate drive roll pressure or a blockage in the contact tip or liner. As mentioned earlier, check the contact tip and drive rolls before proceeding to the liner.

Consult the manufacturer of your wire feeder if the feeder relay turns out to be the cause of the problem.

Contact tip burnback — Contact tip burnback, when the wire fuses with the contact tip, occurs occasionally as a normal part of welding. If you are noticing an increase in burnback frequency, it could be a result of using the wrong contact tip recess, holding the gun too close to the workpiece or a faulty work lead.

If you have not changed your welding parameters, shielding gas and base metal, then it’s unlikely the contact tip recess is the cause of the problem. Additionally, if those variables are the same and you are confident you are not welding any closer to the material than normal, it may be time to consider the work lead as the cause of the burnback. Repair or replace a faulty work lead as necessary.

A final cause of increased burnback, erratic wire feeding, is discussed below.

Erratic wire feeding — If the wire is not feeding from the gun at a consistent rate, it is most likely being caused by the liner, drive rolls or contact tip.

Begin troubleshooting an erratically feeding wire by ensuring the contact tip is the correct size for the wire being used, and that it is not damaged from excessive wear by the wire or from heat exposure from the arc.

If the contact tip is worn out from excessive wear, it could be a result of the drive rolls causing small deformities in the wire. After replacing the contact tip, be sure to check for burrs or other abnormalities along the length of the wire and adjust or replace the drive rolls as necessary. Drive rolls that are improperly tensioned, either too tight or too loose, can also lead to erratic wire feeding.

Erratic arc — Interruptions in electrical conductivity are often the primary cause of an erratic arc. These are commonly caused by the wire maintaining only intermittent contact with a worn out contact tip instead of the constant contact required for a consistent arc. Simply replace the worn out contact tip with a correctly sized new one if this proves to be the case.

Other possible causes of an erratic arc, all of which relate to inconsistent electrical conductivity, are a neck that is too straight, a worn or kinked liner, debris built up inside the liner, an improperly trimmed liner and a faulty work lead connection.

Porosity — Holes in the weld bead, called porosity, are almost always caused by problems with the shielding gas coverage. This can be caused by excessive wind blowing the shielding gas away, worn out or damaged diffusers, insulators, o-rings and fittings, a ruptured gas hose, too much or too little gas flow or a faulty solenoid.

If porosity occurs without any changes to your work environment and equipment set-up, troubleshoot the problem by checking all of the above mentioned components and replacing as necessary.

Good GMAW welds are not a product of luck, and poor welds can usually be attributed to operator technique, equipment malfunction or incorrect electrical parameters. Following these maintenance and troubleshooting tips won’t ensure excellent GMAW welds, but it will guarantee that your gun and consumables are not the cause of any problems that arise.

The Road to Welding Automation

Why and When to Take the Journey

Today, more companies than ever are automating portions, if not the entirety of their welding operations. The reasons are many: to address the welder shortage, improve quality, decrease waste and rework, and/or to increase productivity. Not all companies that attempt the automation journey, however, are successful. In fact, those that begin without a well-thought-out roadmap are risking valuable time and investments and are likely to miss the full benefits of welding automation.

On the other hand, companies that begin with a careful examination of their welding needs and current processes—including an accurate assessment of workflow and an evaluation of the potential return on investment (ROI)  and develop a detailed plan with clearly established goals are likely to achieve welding automation success.

What’s the Benefit?

On average, labor accounts for approximately 70 percent of any welded part’s cost.  An automated system has the potential for reducing that cost, as a robot can typically do the work of two to four people, operating without attention deficits or bad days.  Companies cannot, however, simply purchase an automated system and let it go. A skilled welding operator is needed to program the equipment, which may involve additional training to upgrade his or her skill sets, and may also require alleviating this welding operator of some existing tasks.

With the right automated system, a company can significantly improve first-pass weld quality and reduce the need for scrapping or reworking parts. It can also minimize or eliminate spatter, which in turn reduces the need to apply anti-spatter or perform post-weld clean up—both labor-intensive processes. Plus, if a company currently has personnel applying anti-spatter, it may be able to free up that manpower for other, more productive uses elsewhere.

An automated system can reduce overwelding, a common and costly occurrence associated with the semi-automatic process. For example, if a company has welding operators who weld a bead that is 1/8-inch too large on every pass, it can potentially double the cost of welding (both for labor and for filler metals), and over-welding may adversely affect the integrity of the part. Automation can prevent this problem.

Finally, robots are fast. They don’t have to weld all day to be profitable; they only have to weld more quickly than a manual welding operator—and they do. That fact increases productivity, and creating the same number of parts in a shorter time also decreases labor costs and raises profitability.

While these benefits may immediately beg the question, “How can our company automate?” there are a few questions that need to be answered first.

Repeat That?

One of the first things to ask when considering welding automation is this:  “Does the company have a blueprint, preferably an electronic blueprint, of its parts?” If it doesn’t, it probably won’t meet the basic criterion necessary to ensure the part is repeatable, and repeatability is the key to automation.

An automated system, whether robotic or fixed, needs to weld in the same place every time. If a part’s design is unable to hold its tolerancesif there are gap and/or fit-up issuesthe company will simply be automating a broken process, which in turn, can lead to increased rework and scrap.

If a company currently relies on its welding operators to compensate for fit-up issues, it will need to look upstream in the manufacturing process to ensure consistency. What processes will need to change to make sure uniform parts are sent downstream by these welding operators? Or, if vendors supply the components, can they guarantee that consistency?

Robotics or Fixed Automation?

There is no single automation solution that is best for every company. The best solution will depend on many factors, including the expected lifetime of the job, the cost of tooling involved and the flexibility offered.

Fixed automation is the most efficient and cost-effective way to weld certain components, such as those requiring simple repetitive straight welds or round welds, where the part is rotated on a lathe. For a company that wants to redeploy the asset when the current job ends, however, a robotic welding system offers more flexibility. A robot can also hold programs for multiple jobs, so, depending on volume, it may be able to handle the tasks of several fixed-automation systems.

There is a certain volume of parts that will justify the investment of automation for each company, and an accurate assessment of goals and workflow can help determine what that volume is. If a company makes only small runs of parts, automation becomes more challenging. If, however, a company can identify two or three components that can be automated, a robot that can be programmed to recognize those parts can offer greater flexibility and may benefit even small fabricators who may not have significant volume of a single part.

Although a robot is more expensive than a fixed-automation system, companies should be sure to consider the cost of the necessary tooling before deciding between the two. Fixed automation systems can become quite expensive if extensive changes are required to retool a part to ensure it can be welded consistently.

Ready to Automate?

A streamlined workflow is one of automation’s benefits. To achieve it, however, it is necessary to look beyond the weld cell to ensure your facility can accommodate a smooth flow of materials. It would make little sense, for instance, to invest in an automated system to increase your productivity and then place it in a corner where each part has to be handled twice.

Companies should have a dependable supply of parts in order to avoid moving a bottleneck from one area to another and should also look at the expected cycle time of the robot. Can personnel supply parts to keep up with the demand of the automated system’s cycle time?  If not, the supply of parts, including where they are stored and how they are moved, will need to be adjusted if automation is to be successful.  Otherwise, a robot will sit idle waiting for components to come down the line—a costly and counterproductive state for a company to find its automated welding system.

Companies will need to have the right power and gas systems in place or factor in the cost of implementing these systems.  To move to an automated system, a facility needs a 480-volt, three-phase power supply, as well as bulk delivery of gas and wire. A gas manifold system may add to the initial cost of automation, but will minimize downtime for changing gas cylinders in the long run. 

Determining who will oversee the automated system and providing training is also essential. Most robot OEMs offer a weeklong training course explaining how to operate the equipment. This course, followed by a week of advanced programming, is recommended.

Because there is more to welding automation than simply purchasing a robot, partnering with a competent integrator or automation specialist can help ensure success. The automation specialist will…

• Help determine if parts are suitable for automation, and, if not, what is required to make them suitable.
• Analyze the workflow and facility to identify potential roadblocks.
• Analyze the true costs involved, including facility updates and tooling.
• Determine the potential payback of the automation investment.
• Help identify goals and develop a precise plan and timetable to achieve those goals. 
• Explain automation options and help select those that best fit the company’s needs.
• Help select a welding power source that has the flexibility to maximize travel speed, minimize spatter, eliminate over-welding, provide great arc starting characteristics and increase first-pass weld quality.

Remember, there is no single path to successful welding automation. Still, a well-thought-out plan that includes accurate evaluations is a good start to the journey.

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Don’t Be Marginalized

Learn How Peripherals Can Maximize Your Robotic Welding Performance

Robotic welding systems introduce speed, accuracy and repeatability into the fabrication process. The repeatability of these systems can increase productivity and reduce welding production costs, thereby maximizing the return on the investment in automation. When compared to semi-automatic welding operations, a robot has the ability to perform the same or more tasks, with extreme precision and a lower labor cost per part.

Still, achieving these results isn’t subject to chance. It’s the result of careful equipment purchases, software programming and operator training.  In many cases, it can also be the result of complementary equipment called peripherals. 

Peripherals are any equipment integrated into the robotic welding process with the objective of maximizing its effectiveness and protecting the overall equipment investment. In short, these devices (in most cases) can add significantly to the ROI a company achieves with its welding robot. The key to successful peripheral selection and usage, like that of any other equipment, is simply a matter of education.

Get a Grip

All robotic welding systems require some form of collision detection in order to reduce the damage to both the robot and the welding system in the event of an impact. Impacts occur for several reasons. These include a robotic gun colliding with an incorrectly positioned work piece or tooling that has been left out of position, or striking an item that has inadvertently been left in the weld cell. 

Depending on the type of collision detection utilized by the particular robot manufacturer, it will require either a shock sensor or safety clutch as protection. In cases where collision detection is integral to the robot, a clutch is not required.

The sensitivity of a clutch or shock sensor can be calibrated to accommodate the robotic welding gun’s mass and moment of inertia.  The function of a clutch is both mechanical and electrical. The clutch first recognizes the physical impact of the torch on a solid surface, which sends an electrical signal back to the robot controller, causing the system to stop. This action prevents damage to the robot and the robotic gun. It also alerts the welding operator overseeing the operation that there is an incorrect variable in the weld cell.

Some robotic systems are capable of monitoring current rates and/or torque via robot collision detection software that stops the robot in the event of an impact. In this situation, a solid arm mount would be used in lieu of a clutch on conventional style robots. As its name implies, a solid arm mount is just that: solid. It does not provide electrical feedback during an impact, but rather relies on the software to stop the robot during an impact.

Clutches and solid arm mounts are also quite robust and require little to no maintenance to keep them operating to their fullest. However, should a company feel that maintenance or repairs are necessary for one of these peripherals, maintenance personnel should contact their welding distributor, integrator or robotic equipment manufacturer for advice.

Making the Cut

For companies whose robotic welding applications require consistent welding wire stick-out (the distance the wire extends from the end of the contact tip) when the arc initiates, a wire cutter is recommended.  Note, consistent welding wire stick-out is not required for all applications.

Again, as its name implies, a wire cutter cuts the welding wire to a specified length or stick-out and/or it also removes any balling at the end of the wire. In doing so, this peripheral helps provide smooth arc starts. It also helps attain reliable, repeatable welds, as many companies who own automated systems program the robot to seam track, or find the joint, with touch sensing. This touch sensing depends on the robotic MIG gun having a consistent length of wire with which to locate the correct spot and begin welding.

Most wire cutters are designed to cut a range of different types of welding wire, including stainless steel, flux-cored and metal-cored, usually up to 1/16-inch diameter. They can often be mounted on a nozzle station (to be discussed later) or remotely located to be used as needed.

Inspected and Ready to Weld

Another key peripheral is a neck (or gooseneck) inspection fixture. A neck inspection fixture tests the tolerance of a robotic MIG gun’s neck to the tool center point so it can be readjusted after an impact or after bending due to routine welding. Most inspection fixtures will accommodate standard necks for that particular brand of robotic gun. They are designed with a precision-tooled steel base to withstand the harsh robotic welding environment and also to guarantee accuracy after long-term use.

The advantage of adding a neck inspection fixture to a robotic weld cell is two-fold.  One, it ensures the neck meets the specifications to which the robotic welding system has been programmed. Once the tolerance has been determined, a trained welding operator simply adjusts the neck accordingly.  This adjustment helps prevent costly rework due to missing weld joints.  Accurate neck adjustments also prevent the downtime necessary to reprogram the robot to meet the welding specifications with the existing bent neck.

Secondly, a neck inspection fixture can save companies time, money and confusion when exchanging necks from one robotic MIG gun to another. This is especially advantageous for companies that maintain a large number of welding robots. Welding operators can simply remove a bent neck and change it with a spare that has already been inspected and adjusted, and put the robot back in service immediately.  The damaged neck can then be set aside for inspection while the robot is still online. This again lowers downtime and also helps companies save money for extra parts.

Cleaned, Sprayed and Spatter-Free

One of the most important peripherals a company should consider for its robotic welding system is a nozzle cleaning station, also called a reamer. This peripheral can be used by itself or in conjunction with a sprayer that applies anti-spatter compound.

A nozzle cleaning station cleans the robotic gun nozzle of spatter and/or clears away debris in the diffuser that accumulates during the welding process. If a sprayer has been mounted on the nozzle cleaning station, it will apply a water- or oil-based anti-spatter compound to protect the nozzle, diffuser and work piece from spatter after it has been cleaned.

Again, there are several benefits a nozzle cleaning station can have on the robotic welding process. First, by minimizing the accumulation of spatter and debris in the nozzle, it helps lengthen the life of the robotic gun consumables (nozzle, contact tip and diffuser), and of the robotic gun itself.  This longer equipment life translates into less downtime and labor for component changeover and also less cost for equipment—both factors contribute positively to a company’s ROI of its robotic welding system. A clean nozzle also helps provide better weld quality and reduce problems that could lead to rework.

To achieve all of these benefits, it’s important to consider two factors:  one, the location of the nozzle cleaning station, and two, the timing of its use.  Ideally, the nozzle cleaning station should be placed in close proximity to the welding robot so that it is easily accessible when cleaning is necessary. As well, the nozzle cleaning process should be programmed so that the function occurs in-between cycles—during part loading or tooling transfer. In this case, the cleaning time would not be added to the overall cycle time  per part, as a typical nozzle cleaning station needs only a matter of three or four seconds to complete the job.

If a company attaches a sprayer to its nozzle cleaning station, it should be certain to use only the minimum amount of anti-spatter compound required for the application.  Excessive anti-spatter usage can lead to unnecessary costs and the compound may build up on the nozzle, the welding robot and the parts being welded. In the long term, a high spray volume could cause additional problems that are just as bad as spatter build-up itself.

Finally, implementing a preventative maintenance plan for a nozzle cleaning station is imperative to gaining long-lasting results from the equipment. And it’s easy. Simply clean off the peripheral, wiping it free of dirt, debris and/or spatter, on a weekly basis to prevent malfunctions, and in turn, quality issues in the robotic weld cell.

No Peripheral Decision

The decision for a company, large or small, to invest in robotic welding equipment is significant. It requires time, knowledge and a trusted relationship with a robotic welding equipment manufacturer and/or integrator to find the right system for the application. The same holds true for peripherals. And although these devices do add to the initial cost of automating, they can lead to measurable cost savings and profits in the long term. Remember, the goal in robotic welding is repeatability and increased productivity, any additional equipment that can help achieve that result is worth the consideration.

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Is Automation Right for Your Welding Operation?

Considerations to Make Before Investing

Many manufacturers believe that converting their semi-automatic welding processes to a fast, productive, fully automated process is simply a matter of deciding to do it and then applying the money and time to make it happen. Like most things in life, however, it’s not quite that simple. Achieving the many advantages of an automated welding cell first requires careful assessment of the current welding processes and a detailed plan to automate.

Automation Advantages

Whether it is a fixed automation system or a fully automated robot (see Additional Information: Fixed Versus Fully Automated), automating the welding process offers the potential for numerous benefits:

1. Increased productivity
2. Improved weld cosmetics
3. Lower materials costs via less overwelding
4. Lower energy costs
5. Lower manpower costs
6. Excellent reliability
7. Rapid ROI

Attaining all of these advantages depends on how well suited the process is to automation in the first place. The variables determining suitability for automation include the part(s) to be welded, part volume, the facility, incoming power and personnel.

Parts Should Be Easy to Weld

Automated welding systems are built for speed and thrive on repeatability. Parts that present gap, fit-up and access challenges will quickly hobble an automated welding process, as will a part that requires intricate clamping and tooling to hold it in place. As a rule, the human welding operator will always perform better than a robot or fixed automation for parts where weld positions are obstructed or where a part requires precarious placement.

Instead, to automate successfully the parts manufactured upstream from the automated welding cell should be as simple and consistent as possible so the robot can execute the weld at the same place over and over again (if the joint moves, the robot will not be able to weld it). A good way to determine if a part is suitable for automated welding is to supply the robot OEM or welding solution provider with a blueprint of the part that can indicate how repeatable it is. An electronic CAD drawing of the part, which the robot OEM can import into its simulation software, is even better. This drawing helps to visualize the quality of the planned weld and how the part and its tooling can be fine-tuned to optimize the automated welding process.

Another upstream consideration companies should make prior to automating is to assess their parts flow. If the facility wants to implement automation to relieve a bottleneck at the welding cell, then it should be certain there are no delays in upstream part fabrication or rework required before sending parts to the welding cell. The manufacturer also needs to make sure that the human worker supplying the robotic cell can match the cycle time of the automated cell.

If these solutions aren’t possible, companies may want to consider that some robot manufacturers offer automation solutions for upstream applications as well. These machines are equipped with sophisticated part recognition systems that can pick up parts, manipulate them to the correct orientation and deliver them to the automated welding cell. If fabricators doubt the consistency and cycle time of their manual upstream processes, they might consider this more expensive option.

Justify Automated Solutions with High Part Volume

In order to justify an automation investment, companies need to be sure the volume of parts it needs to produce is high enough, as a robot’s key benefit is the ability to produce high volumes of quality welds. Realistically, however, many small fabricators may not have an application with a high part volume. Still, these facilities may be able to select two or three smaller volume applications and program a robot to weld those different parts instead. Or they might consider investing in a welding cobot system.

Part volume is such a critical factor in estimating the return-on-investment, as up to 75 percent of the cost of a semi-automatically welded component is the labor. Accordingly, even if the facility will be producing the same number of parts, it may be able to justify the investment due to the amount of labor an automated welding process eliminates.

Evaluating the Facility

Facilities need to factor in how much space they can devote to fixed automation and robotics, as the physical footprint of these solutions and the room needed for the flow of raw materials are greater than that of semi-automatic welding processes. Although welding automation can consume large portions of plant real estate, small facilities still can make automation work by purchasing fewer pieces of automation equipment that are programmed to perform multiple tasks. They can facilitate this solution by outfitting robots with various toolsets that enable them to work on diverse jobs while occupying a smaller footprint.

Additional power sources and ventilation will probably be needed when integrating automated cells. The optimum power supply for a fabricator that uses automation is 480 volt three-phase. The facility also needs to consider bulk delivery for both wire and gas. Instead of buying 40 lb. spools, for instance, the facility would need to purchase 600 or 900 lb. drums. In terms of gas delivery, the priority is to limit robot downtime, which can be achieved by investing in manifold systems that will eliminate the downtime associated with frequent bottle change-outs.

Many manufacturers opt to work with a third-party integrator after they’ve decided to implement automation. System integrators are knowledgeable about all aspects of facility modifications necessary for automation, including important safety regulations that apply in the fabricator’s region, country or state, in addition to those specified by OSHA and A3 Robotics (Association for Advancing Automation).

Supervision of the Automated Cell

Automation doesn’t necessarily imply complete independence from human insight and supervision. A skilled welder who knows the process should be available to program the robot or fixed automation system and to troubleshoot the automated welding process as needed. If such a person is unavailable or a new hire is unworkable, facilities should be prepared to vet robot OEMs to determine the availability and costs associated with OEM-based training of their personnel. Some automation companies may offer deals that include training for high volume purchases, and companies can expect this training to last one to three weeks depending on the certification level desired.

Prior Planning Prevents Poor Performance

Automating welding processes can dramatically increase production while at the same time decreasing labor costs and improving weld quality. Transitioning to automation, however, shouldn’t be done impulsively – automation is not suited to every facility or process. Manufacturers need to develop a plan that accounts for a variety of factors, including the part to be automated, the facility, part volume and personnel. Failure to complete an upfront evaluation of the current semi-automatic welding process could result in an imperfect automation solution that requires constant “baby-sitting.” With meticulous evaluation of these aspects, however, facilities can transition to an automated process that requires only nominal supervision and generates a solid return on investment.

Additional Information: Fixed Automation Versus Fully Automated

In fixed automation, the torch rotates around a fixed part or vice versa—the part rotates around a fixed torch. Examples are lathe-type application in which a simple part is spun, welded and ejected from the process, or a straight-line weld, in which the torch advances, makes a six-inch weld and retracts to the neutral position in preparation for the next weld. Fixed automation is extremely efficient and cost-effective.

Robotic automation executes complex programmed motions in space to perform welds. Guns mounted on arms with articulated joints enable them to reach, rotate and pivot to gain access to the part. Facilities choose robotic automation when they anticipate frequent job changes or more complex parts, which alter the welding task. Robots offer the flexibility to be re-programmed and re-tasked as the facility’s needs dictate, making them the preferred automation choice for most manufacturers.

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