Pulsed Welding and Through-Arm Robots: What to Know

Pulsed Welding and Through-Arm Robots: What to Know

Estimated reading time: 6 minutes

After early adoption by the automotive industry, the combination of pulsed gas metal arc welding (GMAW) and through-arm robots has become a more common part of automated welding operations in general manufacturing and fabrication. In fact, through-arm robots have largely replaced conventional ones in the last decade as more robot OEMs lean toward that design. 

Closeup of through-arm robotic MIG gun with sparks
After early adoption by the automotive industry, the combination of pulsed gas metal arc welding (GMAW) and through-arm robots has become a more common part of automated welding operations in general manufacturing and fabrication.

Pairing this type of robot with pulsed MIG welding can help companies improve productivity and quality. Through-arm robots, as their name implies, feature a hollow upper-arm casting that allows the welding power cable to run through the center. This design eliminates the need for the cumbersome cable management usually associated with conventional robots. Routing the cables through the arm also prevents them from getting caught on tooling or parts. The design improves joint access by reducing the overall size and shape of the robotic welding gun (i.e., end-of-arm tooling). Pulsed welding enhances the benefits of this combination by helping lessen part distortion, minimizing burn-through — especially in instances when the robot’s tool center point (TCP) is off — and reducing spatter.

The pulsed welding waveforms, however, can create wear on the through-arm robot’s welding gun components, such as welding consumables and welding power cables. Companies need to consider several factors during their selection and operation to gain consistent results and help these components last. 

Understanding the impact of pulsed waveforms

Pulsed welding works well for lap joints on thinner materials, which is why it is prevalent in the automotive industry. Galvanized steel used for vehicle body skins, for example, may be as thin as 0.7 millimeters. Pulsed welding can also be used for thicker materials, up to and beyond 1/4 inch, with good results. 

This welding transfer mode operates as a modified spray transfer process and requires a power source with specific pulsing capabilities. During operation, the welding output switches rapidly between high peak and low background currents. The peak current is responsible for pinching off the molten droplet from the filler metal and easing it toward the weld joint. While this is happening, the background current keeps the arc on and stable but is too low to transfer any filler metal. The weld pool cools slightly while the low background cycle occurs. 

While pulsed welding offers benefits that support quality, the waveforms also cause a higher level of electrical and thermal stress on the through-arm robot’s welding power cable, since it is confined within the arm of the robot as opposed to being externally routed over the arm. The waveforms can also be harsh on welding consumables — particularly contact tips. 

Impact on Contact Tips

The peak amperage values in a pulse waveform can cause micro-arcing inside the contact tip, which leads to higher resistance and ultimately burnback or the fusing of wire inside the bore of the contact tip. Chrome zirconium contact tips are slightly harder than copper tips and resist mechanical wear better in CV applications. However, a pulsed-welding-specific contact tip is needed to combat the electrical wear and micro-arcing and extend tip life in pulsed welding applications. 

Operator changing a power cable on a through-arm robot
Pulsed welding waveforms can create wear on the through-arm robot’s welding gun components, such as welding consumables and welding power cables.

Impact on Welding Power Cables

Pulsed waveforms can be similarly hard on the welding power cable in a through-arm robot. Variations in welding joint access can put stress on the cable as the robot arm articulates, which can affect the current path. Again, the amperage peaks associated with pulsed waveforms can transfer across any open connections. If electrical resistance is high, the current will travel toward an easier path, leading to damage to the copper within the cable and burnt or shorter liners.  

Unfortunately, it is difficult to predict cable failure in a pulsed welding application since there are few indicators. Periodically, the liner may become fused within the welding power cable or become discolored due to the current taking the liner as the path of least resistance as the power cable fails. If any cracks in the power cable jacket or exposed copper appear, it is time to replace the cable.

Ways to combat wear

There are steps companies can take to help minimize wear caused by pulsed waveforms to make through-arm robot components last longer.

1. Use Contact Tips for Pulsed Welding

As mentioned previously, companies can look for contact tips designed specifically for pulsed welding. These are made from materials that better resist electrical stress and also tend to have a tighter inside diameter (ID) in the bore to reduce the opportunity for the welding wire to float. This helps the contact tip conduct electricity much more efficiently and for longer while maintaining a tighter TCP. These contact tips can also help minimize burnback. 

2. Check Contact Tip to Work Distance

Paying attention to contact-tip-to-work distance (CTWD) is also important. It needs to be consistent along the entire length of the weld joint. This supports correct parameters in the pulsed welding process and reduces spatter that could shorten the life of the contact tip. 

3. Select the Best Welding Power Cable

Welding power cables with a dynamic or sliding electrical connection help ensure electricity can pass through uninhibited even when the cable experiences mechanical stress from the robot’s movements. This improves the ability of the pulsed waveform to transfer current more efficiently. Companies should also select a power cable with reliable, consistent electrical connections and consider replacing the cable annually in high-production environments. 

4. Improve the Robot Arm Path

Improving the path of the robot arm, to ease extreme bending and twisting at joints five and six (J5/J6), is another way to minimize power cable wear. There are means to program the through-arm robot so that it can reach the weld joints efficiently without impacting cycle time. Often the movements that companies need to change the most are air moves and wait or clear positions. The key is to use the robot arm in the most neutral position to reduce stress on the welding power cable, which can be done by minimizing the articulation of J5/J6 during welding and/or air movements.

Gaining the best results

In the right application, pulsed welding with a through-arm robot can help companies improve weld quality and productivity. Working with a trusted robot integrator, distributor and/or welding gun manufacturer can help ensure that the proper consumables and welding power cables are in place, as well as assist in programming the robot to provide the most efficient movements. 

Republished Welding Journal (August 2022) with permission from the American Welding Society (AWS). Click here to view the original article.


The Value of Welding Consumables Trials

The Value of Welding Consumables Trials

In both semi-automatic and automated welding cells, the upfront cost of welding consumables is low compared to the overall expense for equipment, materials and labor. Yet when companies accrue downtime for excessive welding contact tip changeover or troubleshooting poor wire feeding associated with liner issues, costs can quickly compound. 

AccuLock consumable systems including contact tips, nozzles, gas diffusers, liners
Welding consumables trials can bring benefits by uncovering opportunities for improvement.

At times, companies may try to mitigate consumable problems without a true sense of the root cause, implementing a solution without data to back up the decision. However, conducting a welding consumables trial can provide insight into whether an operation is using the best consumables for the application. 

Welding contact tips are the baseline for these trials since they are the most frequently changed consumable. Nozzles and diffusers that are compatible with the contact tip are included in a trial but not monitored in the same way since they last much longer. 

This article has been published as an exclusive with The Fabricator. To read the entire article, please click here.


Understanding the Impact of Time Sinks in Robotic Welding

Understanding the Impact of Time Sinks in Robotic Welding

Estimated reading time: 7 minutes

No robotic welding cell operates at 100% capacity. Parts handling, fixturing, periodic rework and even employee breaks all affect a robot’s ability to be completely efficient. However, there are common time sinks that can further hinder productivity — and they can easily lead to increased costs and lower quality. 

Time sinks are activities that consume a lot of time for little benefit. So why do these happen? It could be a lack of training or lack of skilled labor. Or it could be simply out of habit; some activities may fall into the “we’ve always done it this way” category. 

Closeup of through-arm robotic MIG gun welding with sparks
Time sinks are activities that consume a lot of time for little benefit in a robotic welding operation. They may occur due to lack of training or skilled labor, and even out of habit.

The key is to take steps to rectify these issues quickly, as they can easily escalate. That is especially true on large production lines. If one robot has an issue, it may result in having to stop an entire line of robots to solve the problem, compounding downtime. 

Streamlining the process

Downtime for certain activities in a robotic weld cell is unavoidable, but they become time sinks when they aren’t streamlined. Welding contact tip changeover is a prime example.

While regular changeover is imperative to producing quality parts, it is not uncommon for operators to replace a contact tip before it is necessary. It can become a habit to change the tip every few hours, during breaks and before and after shifts without truly knowing whether there is still life left in the consumable. This frequency interrupts production, resulting in fewer parts being made and increased costs for the tip itself. 

Conducting a time study to determine the true life of a contact tip — from installation to the point of failure — can help companies avoid excessive changeover and costs. The study may be time-consuming initially, but it can be conducted in one robotic welding cell to establish a baseline and then applied to similar cells.

Operator replacing power cable on a through-arm robot
It’s important to remember that changes and improvements aren’t one-time occurrences. They must be monitored regularly and adjusted as needed

It’s also recommended to try different types of contact tips to ensure that the best option is in place. For example, pulsed MIG welding applications are especially harsh on tips, so it’s essential to have an option for that waveform, like the AccuLock™ HDP contact tips, to extend product life. There is a higher upfront cost for these tips, but also a significant increase in productivity and throughput due to significantly less-frequent changeover.

Reaming too often can also become a time sink in a robotic welding cell. A nozzle cleaning station (or welding reamer) is necessary to clear spatter from the front-end welding consumables and ensure smooth gas flow, but it’s important to determine the optimal frequency for the application. For example, if a robot completes a 2-inch weld and then spends 10 seconds to ream, spray anti-spatter, nozzle-check and wire-cut, that is likely too often. Instead, it may be possible to weld 10 to 20 parts between reaming cycles. Again, a time study can help determine the appropriate frequency. 

Common time sinks and tips for avoiding them

True time sinks may not be immediately obvious and the activities themselves may appear benign, but they can have consequences that result in extra time, labor and costs for welding troubleshooting. Fortunately, there are options to rectify these issues. 

Product image of AccuLock R consumables including nozzles, contact tips, gas diffusers
Welding supervisors and operators should schedule time to perform preventive maintenance, such as checking connections and visually inspecting consumables for spatter, during routine pauses in welding.

1. Poor wire conduit management

Due to the high volume of parts that pass through a robotic welding cell, most companies employ large welding wire drums to minimize changeover of these packages. Poor management of the conduit leading from the drum to the robot can lead to time sinks. If this conduit is too long, has been placed around the corner or snakes and bends along the floor, the wire won’t feed properly. Poor wire feeding can lead to burnbacks that require downtime for welding contact tip changeover. It can also cause the arc to become erratic, which causes quality issues and potential rework. The best way to resolve this issue is to keep the conduit as straight as possible and use the shortest run feasible. 

2. Incorrect robot positioning and neck selection

Many large companies, such as tier-one automotive suppliers, measure their efficiency based on available square footage, so placing many robots in an area is common. This helps meet high production goals. However, if a company positions the robot incorrectly in relation to the tooling, it can increase robot articulation and lead to premature cable failure. The same holds true when using the wrong robotic MIG gun neck. While companies often like to standardize on one neck angle throughout the operation, it may not allow the robot to articulate properly to reach the weld joint. 

As a best practice, the robot riser should be sized to minimize the amount of joint articulation when accessing the tooling. This reduces stress on the robotic MIG gun and the power cable. Select the appropriate neck angle to achieve the best joint access. 

Robotic welding supervisor programming conventional robot
When there are jobs to be done, it’s easy for companies to focus on moving production along and sending parts out the door. In the process, time sinks can occur that may be overlooked for long periods of time, compounding their severity.

3. Troubleshooting on the line

When something goes wrong in a robotic welding operation, often the first instinct is to try to troubleshoot the issue on the spot. Doing so yields little benefit since it stops production: not just because the robot isn’t working, but also because multiple personnel may be stepping away from their jobs to address the problem. That adds up to unnecessary time and money spent. 

A better option is to remove and replace the component causing the trouble, whether it be the robotic MIG gun or a welding reamer. That allows the robot to go back to work producing parts, while maintenance troubleshoots and repairs the equipment issue offline. 

4. Overlooking preventive maintenance (PM)

Like troubleshooting on the line, reactive maintenance can be a significant time sink. Addressing unexpected problems keeps the robot from its job of producing parts. Also if something goes wrong within the weld cell because PM wasn’t performed, it can lead to poor quality parts, rework or costly repairs. 

Instead, welding supervisors and operators should schedule time to perform preventive maintenance, such as checking connections and visually inspecting consumables for spatter during routine pauses in welding. More time-consuming PM activities, like replacing a gun liner, a robotic MIG gun or cable, or cleaning the robot, can happen between shifts or during other planned downtime. 

Making a difference

When there are jobs to be done, it’s easy for companies to focus on moving production along and sending parts out the door. In the process, time sinks can occur that may be overlooked for long periods of time, compounding their severity. 

However, pausing to look at the robotic welding operation and setting plans in place can help create efficiencies in the long run. In addition to time studies, conducting a process failure mode analysis (PFMA) can help by considering anything that could go wrong in the robotic welding cell. These situations are then ranked by potential frequency and severity and a plan put in place for addressing them. 

It’s also important to remember that changes and improvements aren’t one-time occurrences. They must be monitored regularly and adjusted as needed. Coordinating a continuous improvement team to spearhead the process can help, as can working with a trusted welding equipment or robot manufacturer.


How to Reduce Welding Gun Wear and Extend Gun Life

How to Reduce Welding Gun Wear and Extend Gun Life

Estimated reading time: 5 minutes

Knowing the common causes of MIG gun wear — and how to eliminate them — is a good step toward minimizing downtime and costs for addressing issues. 

Like any equipment in a welding operation, MIG guns are subject to routine wear and tear. The environment and the heat from the arc, along with other factors, impact their longevity. When operators follow best practices for their use, however, most quality MIG welding guns can last at least one year in a manufacturing environment. Routine preventive maintenance can also help extend product life. 

Closeup side view of welder welding on a part
Knowing the common causes of MIG gun wear — and how to eliminate them — is a good step toward minimizing downtime and costs for addressing issues.

What causes MIG gun wear? 

The welding environment and application can affect MIG gun life. Some of the most common causes of gun wear include: 

Temperature changes

Extreme temperature fluctuations can affect the condition and expected life of the MIG gun jacket, which is typically a rubber-type composite material. If temperatures fluctuate from high to low, the jacket material will react differently — becoming softer or harder — which eventually leads to wear.

Environmental damage

Whether you’re welding inside a facility or on an outdoor jobsite, dirty conditions can introduce abrasives and debris into the MIG gun circuit and consumables. Guns can also be damaged if they are dropped, run over, walked on, or caught in a lift arm or boom. These actions can damage the cable or cause disruption of the shielding gas flow. Welding on or near abrasive surfaces can cause cuts to the gun jacket or cable. It’s not recommended to weld with a MIG gun that has a damaged jacket. Always replace worn, damaged or cracked guns or cables.

Lack of proper maintenance

When dirt and debris build up within the gun liner or on the contact tip, it increases resistance and causes additional heat buildup — the enemy of gun life. A wire feeder that isn’t feeding properly can also cause damage elsewhere in the gun. 

A broken handle or noticeable chips or cuts in the gun jacket or cable are common indicators of MIG gun wear. But other signs aren’t always visible. 

If a burnback, erratic arc or poor-quality welds are an issue during welding, these could be caused by inconsistent power being delivered to the weld circuit. Worn connections or components in the welding gun can cause these power fluctuations. To avoid downtime and additional wear on the gun, it is important to troubleshoot weld or arc issues and fix them as quickly as possible. 

Shot of Bernard gun offering in a row with each being held by a different gloved hand
Keeping an eye on MIG gun wear and changing consumables as necessary can help prolong gun life and deliver better performance for longer.

Tips for preventing MIG gun wear 

Consider these five tips to help optimize gun performance and longevity. 

  1. Don’t exceed the duty cycle. Manufacturers have the option of rating their guns at 100%, 60% or 35% duty cycle. Duty cycle is the amount of arc-on time within a 10-minute period. Exceeding the gun’s rating can result in excess heat that wears gun components more rapidly and can potentially damage them to the point of failure. If an operator feels the need to increase parameter settings to achieve the same weld they previously completed, this could be a sign that the gun has begun to fail or something is wrong with the weld circuit. 

  2. Use a quality jacket cover. To protect the cable from gashes or sharp objects in the welding environment, use a gun jacket cover made from a material that offers a higher abrasion resistance. Jacket covers are available in various lengths to suit many gun styles and sizes. Be sure to replace the jacket as needed for maximum protection. 

  3. Check consumable connections. Any loose connection in a weld circuit will increase heat and resistance, which in turn will increase wear on the gun and components. When changing consumables, be sure threads are clean and tight. Inspect the gun regularly, tightening any loose connection — whether it’s the diffuser, neck or contact tip. Loose connections inhibit power transfer within the circuit for the weld. It’s also important to check all connections after servicing the gun or changing consumables.

  4. Properly manage the cable. The best condition for any weld cable and gun is to keep them as straight as possible during use. This provides better wire feeding and power transfer down the length of the gun. Avoid kinking the cable or using a gun and cable that are too long for the space. When the gun isn’t in use, be sure to coil the cable properly. Keep the gun and cable off the floor or ground and out of harm’s way — ideally on a hook or shelf. Keep guns out of heavy traffic areas where they could be run over or damaged. Also, if the gun is on a boom, don’t pull the gun cable to move the boom or cart. This can damage the connections and wear them down faster. 

  5. Conduct preventive maintenance General maintenance and upkeep will help MIG guns perform as expected and prolong gun life. Pay attention to any signs of wear on the gun or consumables. Check all connections each time the gun is used and look for spatter buildup in the nozzle. Troubleshoot any gun or wire feeding issues as soon as possible. Also, be sure to use the correct parts when servicing or repairing a MIG gun. MIG gun manufacturers typically have a parts guide that indicates which parts go into a specific position on the gun. If the wrong parts are used, they will change the way power transfers through the gun as well as affect overall performance. This can increase wear over time. 

Optimizing MIG gun life

Getting the most life out of your MIG welding gun involves numerous factors, from proper maintenance and care to using best practices when welding. Keeping an eye on MIG gun wear and changing consumables as necessary can help prolong gun life and deliver better performance for longer. 


8 Manufacturing Cost-Reduction Strategies for Welding Operations

8 Manufacturing Cost Reduction Strategies for Welding Operations

Cost overruns in a manufacturing welding operation can come from many places. Whether it’s a semi-automatic or robotic weld cell, some common culprits of unnecessary costs are unplanned downtime and lost labor, consumable waste, repairs and rework, and lack of operator training. 

Image of welder from behind adjusting settings on a Miller power source

Many of these factors are tied together and influence each other. A lack of operator training, for example, can result in more weld defects that require rework and repair. Not only do repairs cost money in additional materials and consumables used, but they also require more labor to do the work and any additional weld testing.  

Repairs can be especially costly in an automated welding environment, where constant progression of the part is crucial to overall throughput. If a part isn’t welded correctly, it may still continue through all steps of the process. If the defect isn’t caught until the end of the process, all the work must be redone. 

Companies can use these eight tips to help optimize consumable, gun and equipment performance — and reduce costs in both semi-automatic and robotic welding operations. 

This article was published as an exclusive on thefabricator.com. Read the full article here.


Cobots and Cobot MIG Guns: What To Know for Manufacturing Welding Operations

Cobots and Cobot MIG Guns: What To Know for Manufacturing Welding Operations  

Traditional robotic welding systems can deliver many benefits, but they aren’t always the right solution for every manufacturer. In applications where implementing a robotic weld cell isn’t the answer, some companies are turning to collaborative robots, or cobots.

While not new to the industry, cobots are currently a fast-growing and still-developing technology. They can help operations save time, improve part quality and deliver consistency — all at a lower investment cost than a robotic welding system. 

Hirebotics-action-shot
Knowing the basics of cobots goes beyond just the equipment itself. It’s also important to understand how the welding gun and consumables selection play key roles in optimizing this technology. (Photo courtesy of Hirebotics)

Knowing the basics goes beyond just the equipment itself. It’s also important to understand how cobot welding gun and consumables selection play key roles in optimizing this technology. 

Why cobots?

Cobots are still industrial robots, but they are designed to operate safely alongside workers and enable human collaboration with the robot. As an example, a cobot may be welding a workpiece while the nearby operator inspects and cleans a weld that was just completed by the cobot — essentially turning one worker into two. 

Manufacturers with high-mix, low-volume production (those that make smaller numbers of a wide variety of parts) are a good fit for cobots, making general manufacturing and job shops common adopters. 

Product shot of a Tregaskiss BA1 cobot MIG gun ready to weld a flat part
A gun like the Tregaskiss BA1 cobot MIG gun features metal-to-metal connections that hold it in place in the mounting arm and keep the aluminum-armored neck firmly connected in the gun body to ensure accurate, quality welds.

There are several benefits that can help operations save time and money while improving part quality. These include: 

1) Lower total cost

Cobots are typically less expensive for operations to adopt compared to a fully automated welding cell. This includes the initial cost of the equipment and the training required to get operators up to speed for programming and using it. In addition, many companies that provide robot integration offer leasing options for cobots, making it easy for manufacturers to try out the solution before making a purchasing decision.

2) Ease of use and training

Cobots have intuitive touch-screen user interfaces and are significantly easier to use than traditional robotic welding cells. Operating a cobot requires some training, but little welding or programming experience is necessary to successfully operate it. Compare that to a traditional robotic welding cell, which typically requires more extensive welding or programming experience. The reduced level of training with cobots can be a plus for operations that struggle to find and retain skilled labor. 

3) Reduced safety risks

Because cobots are designed to be operated with human interaction, they have many built-in safety measures. They are limited in how fast they can move, are very sensitive to collisions, and they do not have pinch points. They will stop movement in the event of a collision. And because of these design parameters, the cobots will not be moving very fast if they do collide with something. Cobots can be programmed to move faster when they are not working alongside a human. 

4) Portability

Many cobots are portable — essentially a table with a robot on it. They can be moved elsewhere in the facility to be used where they are needed. This allows operations to easily change which production line is using it.

Implementing cobots 

Close up of a Tregaskiss BA1 cobot MIG gun on a UR cobot model
The Tregaskiss BA1 cobot MIG gun (shown here on a UR model) has minimal fasteners and a precision-machined keyway mounting system, making installation of the gun and mounting arm quick, easy and accurate. 

Cobots are designed to offer a low barrier to entry — with fast setup and high ease of use. The programming required and specifics of the user interface will vary based on the integrator, but often the cobot is controlled by a tablet or cell phone app — making training and programming very easy. Some cobots are assembled before they are shipped, so setup only takes 30 minutes to an hour. 

Once set up, operators can move the cobot to exactly the spot they want to start the weld and push a button to save that point. Then they can move the cobot to the end point of the weld and save that point. This can be easily repeated for each weld.

Some cobots allow the addition of different features to the programming, such as seam welds or stitch welds. 

Choosing a welding gun and consumables 

While it’s easy for the selection of a welding gun and consumables to be an afterthought in the process, these play an important role in the performance and efficiency of any welding system, including a cobot. 

Choose a high-quality gun and consumables to optimize results, provide longer product life and reduce the time and money spent on troubleshooting. Reducing consumable changeover and potential issues is especially important for companies with less-experienced operators. 

Product shot of AccuLock R gas diffuser, contact tips, nozzle with liner
Look for consumables, like AccuLock™ R, that are designed to maximize production uptime through long service life and quick replacement. 

MIG guns for cobots are tested and rated using the same standards applied to traditional MIG guns. Be aware of what the rating means when selecting a MIG gun for cobot welding, as it helps prevent overheating when guns are used as they are rated. 

A gun like the Tregaskiss BA1 cobot MIG gun features metal-to-metal connections that hold it in place in the mounting arm and keep the aluminum-armored neck firmly connected in the gun body to ensure accurate, quality welds. It also has minimal fasteners and a precision-machined keyway mounting system, making installation of the gun and mounting arm quick, easy and accurate. 

To simplify maintenance, consider a front-load liner, since these can reduce downtime for changeover. The liners are replaced from the front of the gun without disturbing the gun, wire or feeder connection. Liner issues and challenges with liner replacement are a common cause of troubleshooting with both cobot MIG guns and traditional robotic ones. Having an easier liner replacement process helps reduce or avoid problems. 

Look for consumables, like AccuLock™ R contact tips, nozzles and gas diffusers, that are designed to maximize production uptime through long service life and quick replacement. Since contact tip cross-threading issues can be a source of downtime in welding operations — especially with less experienced welding operators — these consumables feature coarse tip threads that help to eliminate the problem. They also feature increased mass and are buried within the diffuser, away from the weld, to increase tip life. 

Cobots in welding 

In the right manufacturing operation, cobots can help improve productivity and efficiency and lessen the strain on operations having difficulty finding skilled welders. 

However, users expect a quick-to-implement and easy-to-use solution that keeps their operations agile and profitable. Choosing durable, high-quality cobot MIG guns and consumables for a cobot system can keep operators focused on manufacturing quality parts instead of troubleshooting or maintenance. This helps operations achieve their productivity and quality goals — and get the results they want. 


Creating a Smooth Wire Feeding Path for MIG Welding

Creating a Smooth Wire Feeding Path for MIG Welding

In MIG welding applications, having a smooth wire feeding path is critical. The welding wire must be able to feed easily from the spool on the feeder through the power pin, liner and gun and up to the contact tip to establish the arc. This allows the welding operator to maintain consistent levels of productivity and achieve good weld quality, while also minimizing costly downtime for troubleshooting and potential rework. 

Side view of a welding operator MIG welding with Miller machines in the background
In MIG welding applications, having a smooth wire feeding path is critical. The welding wire must be able to feed easily from the spool on the feeder through the power pin, liner and gun, and up to the contact tip to establish the arc.

However, there are several issues that can disrupt wire feeding. These can cause a host of problems, including an erratic arc, burnbacks (the formation of a weld in or on the contact tip) and birdnesting (a tangle of wire in the drive rolls). For new welding operators who may not be as familiar with the MIG welding process, these problems can be especially frustrating. Fortunately, there are steps to easily prevent problems and create a reliable wire feeding path. 

Welding liner length has a big impact on how well the wire will feed through the entire path. Too long of a liner can result in kinking and poor wire feeding, whereas a liner that is too short won’t provide enough support to the wire as it passes through. This can ultimately lead to micro-arcing within the contact tip that causes burnbacks or premature consumable failure. It can also be the cause of an erratic arc and birdnesting.

Trim the liner correctly and use the right system

Unfortunately, welding liner trimming issues are common, particularly among less experienced welding operators. To take the guesswork out of trimming a welding gun liner correctly — and achieve a flawless wire-feeding path — consider a system that eliminates the need for measuring the liner for replacement. This system locks the liner in place at the back of the gun, allowing the welding operator to trim it flush with the power pin. The other end of the liner locks at the front of the gun at the contact tip; it is concentrically aligned between the two points, so the liner won’t extend or contract during routine movements. 

Illustration of nozzle cutaway showing an AccuLock S contact tip
A system that locks the liner in place at the back of the gun and at the front provides a smooth wire feeding path — all the way through the neck to the consumables and the weld — as illustrated here.

When using a conventional liner, avoid twisting the gun when trimming the liner and use a liner trim gauge when provided. Liners with an interior profile that imparts less friction on the welding wire as it goes through the liner are a good choice for achieving efficient wire feeding. These have a special coating on them and are coiled out of a larger profile material, which makes the liner stronger and offers smooth feeding. 

Use the right contact tip and install correctly

Matching the welding contact tip size to the diameter of wire is another way to maintain a clear wire feeding path. For example, an 0.035-inch wire should be matched to the same diameter contact tip. In some cases, it may be desirable to decrease the contact tip by one size to gain better wire feeding and arc control. Ask a trusted welding consumables manufacturer or welding distributor for recommendations.

Look for wear in the form of keyholing (when the contact tip bore becomes worn and oblong) since this can cause a burnback that prevents the wire from feeding. 

Be sure to install the contact tip correctly, tightening it past finger tight to avoid tip overheating, which can hinder wire feeding. Consult the operations manual from the welding contact tip manufacturer for the recommended torque specification. 

Illustration of wire feeder drive wheels with a birdnest of wire
An improperly trimmed liner can lead to birdnesting or a tangle of wire in the drive rolls, as illustrated here. 

Choose the right drive rolls and set tension properly

Drive rolls play a significant role in ensuring a MIG welding gun has a smooth wire feeding path. 

The size of the drive roll should match the size of the wire being used and the style depends on the wire type. When welding with solid wire, a V-groove drive roll supports good feeding. Flux-cored wires — both gas- and self-shielded — and metal-cored wires work well with V-knurled drive rolls. For aluminum welding, use U-groove drive rolls; aluminum wires are very soft, so this style won’t crush or mar them. 

To set the drive roll tension, turn the wire feeder knob to one half turn past slippage. Pull the trigger on the MIG gun, feeding the wire into a gloved hand and slowly curling it. The wire should be able to feed without slipping. 

Understand the impact of welding wire on feedability

The quality of welding wire and the type of packaging it is in both affect wire feeding. High-quality wire tends to have a more consistent diameter than low-quality ones, making it easier to feed through the entire system. It also has a consistent cast (the diameter when a length of wire is cut off the spool and placed on a flat surface) and helix (the distance the wire rises from the flat surface), which add to the wire’s feedability. While higher-quality wire may cost more upfront, it can help reduce long-term costs by minimizing the risk of feeding issues. 

Illustration of a nozzle cutaway showing a contact tip burnback
Inspect the contact tip for keyholing, as it can lead to burnbacks (the formation of a weld in or on the contact tip) as shown in this illustration. 

Wire from large drums typically have a large cast when dispensed from the packaging, so they tend to feed straighter than wires from a spool. If the welding operation’s volume can support a larger drum, this may be a consideration for both wire feeding purposes and for reducing downtime for changeover. 

Making the investment

In addition to following best practices to establish a clear wire feeding path — and knowing how to quickly troubleshoot problems — having reliable equipment is important. The upfront investment for a high-quality wire feeder and durable welding consumables can pay off in the long term by reducing issues and the costs associated with wire feeding problems. Less downtime means more focus on producing parts and getting them out to customers. 


5 Tips for Robotic Welding Process and Project Planning

5 Tips for Robotic Welding Process and Project Planning

Robotic welding projects can arise in a number of ways — from a smaller shop expanding its capabilities to a large original equipment manufacturer (OEM) awarding new business or even a new company establishing itself within the competitive landscape. 

Closeup of robotic MIG welding gun with sparks
It’s critical to implement a well-thought-out and thoroughly researched plan to ensure a successful robotic welding operation.

Regardless of the circumstances, it’s critical to implement a well-thought-out and thoroughly researched plan to ensure a successful robotic welding operation. The plan should cover both the details related to the welding process and the specific project at hand. This helps companies meet quality and productivity goals while maintaining their cost margins and achieving profitability.

Being proactive is the key with planning. Doing so helps minimize the opportunity for unforeseen risks that could be detrimental to the welding operation. Some basic tips can help along the way.   

Tip No. 1: Ask questions

To determine the desired outcome for a robotic welding operation, it’s important to define the welding process — in terms of how efficient and quick it needs to be — and to consider all details related to the project’s budget. Asking some fundamental questions can help stakeholders define the scope of the process they are using and the project they are undertaking.

  1. What efficiencies do we need from the welding process? 
  2. How labor-intensive will the process be? 
  3. Is there adequate staff for loading/unloading fixtures?  
  4. What training will staff need to keep the robot welding effectively? 
  5. How many robots do we need? And how hard or long do we want the robots to work?
  6. What should we consider about the weld cell ergonomics? 
  7. How should the robots be configured?
  8. What capital is available and how fast do we want our return on investment (ROI) to be? 

Answering these questions can help companies as they plan out their project and conduct cost analysis.

Tip No. 2: Set realistic goals

Along with asking questions to set the foundation for solid process and project planning, it’s also important to set realistic goals. These goals should relate to general processes in the robotic weld cell along with desired quality outcomes. 

For example, when considering the capabilities of the welding process in a robotic cell, a 75% to 80% efficiency rate may be a realistic goal. No welding process is 100% efficient, so it’s important to account for equipment downtime (planned or unplanned), consumable changeover, welding wire drum changeover and more. 

The same holds true for quality goals. Having 100% quality isn’t necessarily true to life since weld defects like porosity can occur, tool center point (TCP) can shift and stampings can become misaligned. Each of these instances is possible (and probable) in an everyday robotic welding operation. 

Setting realistic goals allows time for unexpected occurrences once the robotic welding system is at work. 

Product photo of the TOUGH GUN TT4 reamer with anti-spatter reservoir
Reamers clean spatter from the welding gun nozzle and gas diffuser to ensure smooth shielding gas flow that in turn supports good weld quality.

Tip No. 3: Look at the long term

While it may be tempting for companies to look for ways to reduce upfront costs during process and project planning, this doesn’t ensure that the long-term results are always positive. For example, neglecting to consider (and purchase) supplemental equipment, such as reamers (also called nozzle cleaning stations), can lead to greater expenses over the lifetime of a project. 

Reamers clean spatter from the welding gun nozzle and gas diffuser to ensure smooth shielding gas flow that in turn supports good weld quality. Reamers are available in analog or ethernet models.

It’s important to consider reamer quality, especially for heavy-duty, higher-volume applications. While reamers with heavy-duty construction generally cost more, they also last much longer than light-duty models. Be sure to size the reamer appropriately for the project because reamers vary in the amount of torque they provide when removing spatter. Heavy-duty reamers provide more torque and have cutter blades that can reach deeper into the nozzle for a more thorough spatter cleaning. 

Companies should also determine how much human interaction with the reamer is necessary to keep the welding process at target efficiency levels. For example, implementing a multi-feed anti-spatter sprayer system reduces time and labor for refilling the small sprayer reservoir on the reamer. It can feed multiple reamers from a large drum of anti-spatter solution outside the weld cell.

Tip No. 4: Pay attention to the small details

When it comes to identifying equipment for a robotic welding cell, it may be easy to overlook the importance of robotic MIG guns and consumables. While small in investment compared to a robot, each can have a significant impact on the efficiency of a welding process and the quality of the project. 

Frequent changeover due to poor-quality MIG welding consumables or ones that aren’t appropriate for the application can add up. Be sure to select those that will be compatible with the heat inputs. Brass nozzles are strong and better able to resist spatter adhesion than copper nozzles. However, brass can be brittle at high temperatures, so they are best for lower-heat applications. Copper nozzles are better for high-heat applications but tend to allow greater spatter adhesion. For pulsed applications, where waveforms can be especially harsh on contact tips, an HDP tip can last longer, reducing the frequency of downtime caused by tip changes. The same holds true for contact tips that offer coarse threads to reduce the risk of cross-threading during replacement. When possible, standardize consumables throughout the entire welding operation to bring greater efficiencies. 

Like consumables, the robotic MIG gun selected needs to match the duty cycle of the application to withstand the resistive heat and avoid overheating. The gun should also have an appropriate size of neck for the application to enable access to tooling and the weld joint.

Tip 5: Look for opportunities to optimize

Finding ways to maximize robot uptime is an important part of process and project planning. Robots are expensive, so companies want to be sure that they will get as close to 100% optimization as possible. 

Having a high-quality welding wire, like a metal-cored wire, that supports faster travel speeds is one option to help optimize the robotic welding system. Look for wires with a consistent cast and helix to support smooth wire feeding. 

Preventive maintenance (PM) programs help ensure that a robotic welding system operates efficiently, avoids unplanned downtime and supports more arc-on time. With a preventive maintenance schedule, companies can proactively check and change welding gun liners and MIG welding consumables during planned downtime, while also assessing the power cable and robot for damage. 

It’s also important to plan for the ways that employees can support robot optimization. Training is critical. Properly trained robotic welding supervisors or technicians can be more effective at understanding the process and adjusting equipment as needed. Appropriate training can also help them run the equipment longer and more efficiently. 

Putting everything to work

Once a company considers the key tips for process and project planning, they should be sure that everything works. Trials can help flush out unforeseen problems before starting full production and save money by preventing budget overages to fix issues. 

After a project has been put into motion, take time for reflection. Revisit all aspects to see what worked and what didn’t. Continuing to learn from projects can help companies achieve future success.


Ways Welding Reamers Support Quality, Productivity and Safety

Ways Welding Reamers Support Quality, Productivity and Safety

TOUGH GUN TT4 Reamer

A successful robotic welding operation depends on the ability to maintain high levels of quality and productivity, while also keeping costs low. Unplanned downtime associated with consumable or equipment problems jeopardizes these goals. It can also increase the labor needed for troubleshooting and resolving issues. 

But above all else, the weld cell needs to be a safe place for welding operators to work and interact with one another and the robotic welding system. 

Peripherals, such as welding reamers (also called nozzle cleaning stations), can help companies achieve their goals, while also helping maintain safety. 

This article was published in the August issue of The Fabricator. Read the full article here.


New TOUGH GUN TT4A and TT4E Reamers Power Through 
Spatter to Increase Uptime and Weld Quality

New TOUGH GUN® TT4A and TT4E Reamers Power Through Spatter to Increase Uptime and Weld Quality

WINDSOR, Ontario. (September 14, 2021) — Tregaskiss has introduced its new TOUGH GUN TT4A (analog) and TT4E (ethernet) reamers to maximize uptime and weld quality in robotic welding operations. These nozzle cleaning stations provide superior cleaning performance to power through spatter, improving gas flow and reducing porosity so more time can be spent welding. 

TOUGH GUN TT4 Reamer - front view

Both reamers offer a powerful .95HP motor and 236 pounds of lifting force at 95 psi. Engineered from harder, stronger material, the cutter blades are more resistant to breaking, chipping or cracking.

Adding to the reamers’ performance are several features designed to keep robotic welding operations running for extended periods of time. These include durable valves and cylinders rated for 10M+ cycles and a wire cutter that can run 1M+ cycles without requiring maintenance. The reamers also feature a powerful motor that lasts up to 18M cycles at 80+ psi. A standard motor lubricator supports that performance by extending the life of the motor; it is highly recommended for use in damp and moisture rich environments.

New standard anti-spatter features

Tregaskiss has integrated several new standard features into the TOUGH GUN TT4A and TT4E reamers to help reduce downtime, safety incidents and costly weld defects associated with the use of anti-spatter liquid. 

An anti-spatter reservoir with 20-ounce capacity reduces the need for frequent refills to improve productivity, while a low fluid level indicator sends an alert to the PLC/robot when anti-spatter solution is low. This minimizes the risk of running out and helps prevent poor weld quality from lack of shielding gas due to spatter build up. The reservoir includes a tethered cap and easy-clean filter to protect against anti-spatter contamination, which can also lead to weld quality issues. It mounts directly to the reamer frame to increase durability. The reservoir is compatible with the TOUGH GARD® anti-spatter multi-feed system to provide a continuous supply of anti-spatter solution to up to 10 reamers from a 5-gallon pail or 55-gallon drum.

Also standard is a spray containment unit that captures anti-spatter overspray in an enclosed basin, lessening the potential for slip and trip accidents, improving air quality and reducing downtime and cost for cleanup. The weld cell remains dry and clean.  

Versatile features and additional options

The TOUGH GUN TT4A and TT4E reamers both feature a four-sided v-block that eliminates the need to purchase new v-blocks when changing nozzle styles, while the TT4E model with ethernet provides greater control and flexibility for remote operation. 

Both reamers have external setup switches that allow independent operation of the sprayer, clamp and spindle during manual setup. 

Tregaskiss offers additional options for the reamers to further enhance their versatility, including a wire cutter that removes the ball at the end of the welding wire for smoother starts and consistent stickout, along with a reamer stand. A nozzle detect sensor confirms the presence or absence of a nozzle prior to welding to support consistent weld quality and reduce rework. An optional filter/regulator extends motor life by cleaning the air supply to the reamer and keeping debris from entering the motor. 

For more information about the TOUGH GUN TT4A and TT4E reamers, visit Tregaskiss.com/robotic-nozzle-cleaning-stations/

# # #


AccuLock Consumables Save Time and Money in MIG Consumable Changeover

AccuLock™ Consumables Save Time and Money in MIG Consumable Changeover   

Estimated reading time: 5 minutes

They may seem like small pieces of a welding operation but when consumables aren’t properly installed or maintained, big problems can result — from poor wire feeding to weld quality issues. Related troubleshooting and rework cause costly downtime and lost productivity. 

Consumable changeover can also be a time-consuming part of the welding process, especially if it’s necessary to do it frequently or if less experienced welders install consumables incorrectly. 

Choosing the right consumables can help reduce or eliminate these hassles. Learn how AccuLock consumables can be used for Bernard® BTB MIG guns and Tregaskiss® fixed automatic and robotic MIG guns to help operations save time and money and improve efficiency. 

Family product photo of AccuLock S, AccuLock R consumables systems

Although small in size, both AccuLock R and AccuLock S consumables can deliver sizable time- and cost-saving benefits by reducing troubleshooting and downtime in industrial welding applications. 

The benefits of AccuLock consumables 

AccuLock consumables are designed to address common challenges faced in both semi-automatic and automated MIG welding operations. A switch to AccuLock consumables can help operations: 

  • Increase consumable life while reducing costs and improving productivity. 
  • Reduce consumable replacement errors and the time and money spent on troubleshooting, rework and downtime.
  • Simplify consumables replacement, improving accuracy and reducing employee training. 

The AccuLock consumable family for industrial welding applications includes AccuLock R and AccuLock S systems, two options that are designed to deliver timesaving benefits and optimized performance in automated and semi-automatic welding applications. 

Load and lock for increased productivity and throughput 

The AccuLock S (Semi-automatic) consumables system features liners designed to resolve issues and errors with liner trimming and installation as well as erratic wire feeding problems. Because AccuLock S liners are locked and concentrically aligned to both the contact tip and the power pin, they offer a flawless wire-feed path and error-proof liner replacement every time. In addition, a steel retaining ring on the diffuser helps keep the threaded nozzle in place during use and cleaning. 

The AccuLock R (Robotic) consumables system offers front-loading QUICK LOAD® liners that require less than half the time and effort to replace compared to conventional liners and can be changed from a safe zone in a robotic weld cell. Upgrading to AccuLock HDP contact tips can extend life by 10 times or more in pulsed welding applications. In addition, operations currently using TOUGH LOCK® consumables in robotic and fixed automatic MIG guns can easily upgrade to AccuLock R consumables without affecting TCP or requiring programming changes. 

Choose according to your needs 

When deciding between the two types of AccuLock consumables for industrial welding applications, there are several key factors to consider. It’s important to think about the type of welding being done in the operation and what current issues or challenges need addressing. 

Subscribe to the Amperage enewsletter to have more articles like this on delivered to your inbox.

AccuLock S consumables are best suited for operations with the following issues or characteristics:  

  • Primarily focused on semi-automatic welding with little to no automation. 
  • Dealing with decreased productivity due to liner installation errors, burnbacks, bird-nesting and erratic arc.
  • Wanting to reduce the time and costs of troubleshooting, downtime and rework. 

AccuLock R consumables are best suited for operations with the following issues or characteristics: 

  • Primarily focused on robotic or fixed automatic welding with few semi-automatic guns.
  • Having a complicated and costly consumables inventory that may be the root cause of frequent consumable replacement errors. 
  • Experiencing issues with contact tip cross-threading and want increased tip life. 

Choosing between AccuLock S and AccuLock R on semi-automatic MIG guns  

Customers who are currently using TOUGH LOCK consumables on Bernard BTB MIG guns can upgrade their guns with either AccuLock S or AccuLock R consumables. Although AccuLock S consumables offer many benefits specific to semi-automatic welding applications, in some cases it can make more sense for these welding guns to be upgraded to AccuLock R consumables instead. For example, if a complex inventory of MIG gun consumables is the primary root cause of high carrying costs and consumable replacement errors in a given facility, AccuLock R consumables may offer a better ROI.

Switching existing Bernard BTB MIG guns to AccuLock R consumables is an easy change to make, requiring only an AccuLock R diffuser and an AccuLock contact tip — with no need to switch the liner, power pin, power pin cap or nozzle. 

Successful welding operations simplify inventory 

Both AccuLock S and AccuLock R systems share a common contact tip to simplify inventory management for facilities that choose to use both. AccuLock contact tips last longer due to increased mass and being buried within the diffuser, away from the heat of the weld. Coarse threads work in tandem with a long contact tip tail to concentrically align the tip within the diffuser prior to thread engagement, ensuring quick, accurate replacement without cross-threading.

Getting the most out of MIG gun consumables 

AccuLock S consumables solve many of the issues that can be traced to MIG gun liners that have been trimmed to an incorrect length or that pull out of position inside the MIG gun, creating gaps along the wire feed path. They are a good fit in most semi-automatic applications. 

In fleets with a lot of automated welding, AccuLock R consumables can extend contact tip lifespan (especially in pulsed welding applications), eliminate contact tip cross-threading issues, alleviate excessive downtime for consumables replacement and limit safety issues related to climbing up to access robots or wire feeders for gun liner changes. 

Although small in size, both AccuLock R and AccuLock S consumables can deliver sizable time- and cost-saving benefits by reducing troubleshooting and downtime in industrial welding applications. 


Improve Productivity by Preventing 5 Common MIG Welding Problems

Improve Productivity by Preventing 5 Common MIG Welding Problems

Downtime and rework can be costly for manufacturing operations. The last thing any production team wants to do is the same work twice. If you add to that any time spent troubleshooting issues in the weld cell — the lost production time can start to accumulate quickly. 

There are several steps operations can take to reduce the time lost to these common issues in MIG welding — and many of them start during weld setup and selection of consumables. Read on to learn more about five common causes of lost productivity in the weld cell and how to prevent them. 

Cause 1: Poor fit-up or weld prep

Before welding even starts, pay attention to proper fit-up and joint design, as well as base material preparation and cleaning. Good fit-up means avoiding large or inconsistent gaps between the parts. Choosing the right wire size and gas mixture and matching those in advance can help optimize performance and provide proper gap filling capabilities. 

Closeup of welding operator welding on a square part on a table
There are several steps operations can take to reduce lost productivity in MIG welding — and many of them start during weld setup and selection of consumables

Certain welding wires, such as metal-cored wires, are usable on less-prepped base material by offering the ability to weld through mill scale or other surface impurities. They also offer good gap bridging. If operations are often getting parts that aren’t thoroughly cleaned, it may be worth testing a metal-cored wire. Otherwise, changes to the weld prep stage of the operation may be necessary to achieve better material condition prior to welding.   

Cause 2: Incorrect parameters or system setup

Using the wrong parameters or setting the wire feeder up incorrectly are common causes of lost productivity. Having the wrong settings can greatly affect the weld, sometimes without the operator even realizing the impact that a setting change can make. It’s important to have a thorough understanding of the wire feeder and all of its functions to set it up for optimal performance. 

When properly set up, there should be very few issues with the performance of the MIG welding gun. However, if the system is set up incorrectly or there is a poor weld circuit, it can lead to contact tip failure, since the contact tip is the smallest fuse in the weld circuit. This can result in money wasted on frequent contact tip changeover. 

Cause 3: Improper liner installation

Product shot of AccuLock S nozzle, contact tip, gas diffuser, power pin, liner
With Bernard® AccuLock™ S consumables, 60% of the contact tip is buried in the gas diffuser to protect it from heat damage.

MIG gun liners can wear out over time and must be changed periodically, like other consumables. However, replacement liners are often longer than necessary and must be precisely trimmed according to the style and length of the gun. If a liner is cut too short, it can result in issues like burnback, an erratic arc and wire chatter. When liners are cut too long, it can cause the wire to weave and curve as it feeds through the gun. 

With either too-long or too-short liners, the result is often poor wire feeding and downtime spent troubleshooting these problems. Maintenance and troubleshooting for liner issues can be costly, resulting in multiple hours per week lost for an operation. 

The more that liner movement within the gun can be minimized, the better your wire feedability will be. To avoid the guesswork and hassle, look for a solution that makes liner installation and trimming easier. The Bernard® AccuLock™ S consumable system affixes the liner at both ends of the gun, so welders are assured the liner won’t pull back or push into the contact tip, allowing for smooth, uninterrupted delivery of the wire to the weld pool.

It’s also important to occasionally check to make sure the liner is clear and not blocked by debris or buildup. 

Cause 4: Loose connections or neglected maintenance  

When MIG welding consumables aren’t properly installed and maintained, it can result in wire feeding issues and weld quality problems that lead to lost time for troubleshooting.  

For example, a loose connection in the weld circuit means you’re not getting the power you expect from the power source. In that case, the operator may keep adjusting the parameters, causing an increase in resistance that leads to shortened consumable life. These issues tend to show up first in the contact tip. This is often the first thing the operator changes if they think they have a problem with their MIG gun. Changing the contact tip — even when the real source of the problem is a loose connection or improper setup in the circuit — drives up consumable costs and wastes time. 

Be sure to periodically check and tighten all connections and cables. Tight connections help optimize performance and reduce the chance of issues occurring in the system. 

Cause 5: Cutting corners with contact tips 

Another cause of lost productivity is using low-quality contact tips. Some contact tips are designed for ease of use and high performance. They provide better arc starts, less spatter, more consistent welds and longer life.  

With Bernard AccuLock S consumables, 60% of the contact tip is buried in the gas diffuser to protect it from heat damage. As the shielding gas flows through the gun, it cools the contact tip tail inside the gas diffuser. This helps reduce heat and wear. This also differs from traditional tips that screw onto the gas diffuser with little to no portion of the tip exposed directly to the shielding gas as it exits the diffuser to the arc. The tapered design of the consumables tightly locks the conductive parts together to minimize electrical resistance and further reduce heat buildup. The contact tips also feature coarse threads, making them less likely to become cross-threaded. 

Troubleshooting common welding problems 

Common problems in the weld cell — from poor fit-up or wire feeding issues to using the wrong consumables for the job — can cost the operation significant time and money. Addressing the causes of lost productivity often starts with proper weld prep and setup, as well as making sure the chosen consumables are right for the application. Optimizing setup and efficiency in the weld circuit makes troubleshooting that much faster when issues do arise. 

Implementing a Robotic Welding System: 5 Common Questions Answered

Implementing a Robotic Welding System: 5 Common Questions Answered

Estimated reading time: 7 minutes

Many manufacturing operations want to improve productivity and weld quality. Robotic welding can often help achieve these goals. But success with a welding robot doesn’t happen by chance. It takes a lot of upfront planning to help minimize the time and money you need later to make improvements or fix issues. 

Before getting started, consider how these common questions could impact the way you establish a repeatable and consistent robotic welding operation — and how you can get the most out of it. 

How do I choose the right welding wire?

A: The filler metal used in a robotic welding system plays a critical role, as it can affect productivity, weld quality and overall costs. When you choose a wire for robotic welding applications, consider two things: the type and the thickness of the material being welded. 

Across various industries, solid wire has been the standard for robotic welding. However, metal-cored wire may offer better productivity and higher quality benefits, especially for manufacturers of heavy equipment, automotive exhaust, chassis and wheels. Metal-cored wire not only allows for faster travel speeds and higher deposition rates, but it also more effectively controls spatter levels to reduce post-weld cleanup. Last, it offers improved welding through mill scale, which helps eliminate pre-weld grinding. 

When in doubt, you can get suggestions from experienced welding equipment and filler metal manufacturers to help you match a welding wire to your process needs. 

What type of welding gun and consumables do I need? 

A: Performance in a robotic weld cell is significantly affected by your choice of robotic welding gun and consumables, including the nozzle, contact tip and liner. The right combination of gun and consumables can reduce unplanned downtime, increase lifespan and improve overall equipment effectiveness (OEE) in your weld cell. 

There are three types of robotic guns to choose from, depending on your duty cycle and amperage ratings: air-cooled, water-cooled and hybrid. It’s possible for air-cooled guns to reach ratings of 350 to 385 amps at 100% duty cycle with mixed gases. Guns with this rating are well-suited for a variety of applications and help eliminate the need for water-cooled guns, which can be more complex and expensive to maintain. However, hybrid air/water-cooled designs incorporate water cooling on the front of the neck with an air-cooled cable. This design is good for applications with borderline air-cooled duty cycles that experience a higher frequency of consumable changeover. The hybrid gun is the best option to provide an additional rating boost while effectively cooling the consumables, leading to longer lifespans.
 
Robotic welding systems typically operate at higher duty cycles (compared to semi-automatic welding) and may use transfer modes that can be harsh on consumables. Consider using heavy-duty copper or chrome zirconium contact tips or high-quality tips designed specifically for pulsed welding. Chrome zirconium contact tips resist physical wear (or the keyholing effect) better than copper tips and are ideal for applications with long welds. Make sure to undersize the contact tip from the wire size when using 500-pound-plus wire drums to help ensure consistent wire contact with the tip due to the wire cast. Keep the tips on par with the wire size in small wire packaging. 
Nozzle material also plays a factor in the application. Brass nozzles are stronger and have a lower spatter adhesion compared with copper, but brass is more brittle at higher temperatures. In short, brass handles spatter best while copper best handles higher heat.

Choosing a quality liner pays dividends in reducing your unplanned downtime. The majority of time, burnback in contact tips is a direct result of poor wire feeding or a liner cut too short. An accurately trimmed, quality liner will help to consistently improve wire feeding by reducing drag. The result is longer-lasting contact tips and improved robot uptime.

Chart with information on selecting air-cooled, water-cooled, hybrid robotic MIG guns

How do I select proper weld settings? 

A: Several factors, such as material type, wire size and material thickness, influence the proper weld settings for an application. Some welding power sources have the ability to suggest recommended parameters based on the operator’s input for the application. 

When a machine doesn’t have this technology, finding the correct parameters can involve some trial and error on your part to dial in heat and penetration. Consult with the robot manufacturer, welding power source manufacturer or system integrator. These partners can offer expertise and assist in choosing and testing specific materials to establish the proper weld parameters.

Why is tool center point (TCP) so important?  

A: Establishing an accurate tool center point provides consistency and repeatability across parts and is vital for your system to maintain quality welds.

You can set your own standards for the acceptable amount of TCP drift based on the application and type of welds being made. To set the tolerance of TCP variation, an acceptable starting point can be half of the thickness of the wire diameter. Also keep in mind that your TCP correlates with your contact tip wear — the more key-holed a tip, the more off location your TCP will be.
Touch-sensing features that monitor TCP and track any shifts from the original setting are available on many robotic systems today. If a gun is out of acceptable TCP range, you can remove the neck and recalibrate it to the original specifications with a neck-straightening fixture. TCP can also be automatically adjusted internally by the robot on some systems. 

It’s a good idea to schedule regular TCP checks. For example, it can be done every weld cycle, at the end of every shift or when the gun goes through a reamer cycle. The frequency of TCP checks is a matter of your priority preference. While it can be time-consuming to check after every shift, in the long run it can save money by avoiding rework if problems are caught early.

Closeup of weld cell supervisor programming robot with teach pendant

How do I program the robot path? 

A: Much like programming the weld settings, programming the robot path may also involve some trial and error. When you initially program the robot’s path, think about four factors: the application, the material type, the welding process you are using and the gap size being filled. The travel angle — and whether it’s a push or pull weld — will impact the weld quality and aesthetic. Dialing in the correct path to achieve your desired results can take time. 

Having the robot move to perch points or ready-to-enter points once the home positions are set helps to keep the robot safely away from potential collision areas. It also allows the system to move with air-cut moves to and from these points quickly and effectively. 

When you program the robot to move to a weld, it’s common to set the approach point just above the weld start location. The robot should approach the start location at a slower and safer speed before it strikes an arc. This approach position provides a good lead-in and typically does not require adjustment unless the weld is relocated. Some robotic systems have technology that assists in setting the initial robot path.  

The robot’s welding location can play a role in premature gun failures. Heavy articulation in the gun or an excess of +/-90 degrees, especially during welding, can cause accelerated cable failures. Minimizing your robot’s axis five and six during welding can help extend gun life by reducing wear.

Tips for robotic weld cells 

Many variables, including proper cable and consumables selection and TCP control, play an important role in weld quality and gaining successful results with a robotic welding system. Establishing a thorough plan before implementation and continuing to monitor key issues can help you optimize your OEE so you can get the most out of your investment. 


Manufacturer Cuts $45,000 of Costs With New MIG Welding Guns and Consumables

Manufacturer Cuts $45,000 of Costs With New MIG Welding Guns and Consumables

General Kinematics — a premier manufacturer of vibrating equipment for processing bulk materials — has been providing consistent, on-time and innovative solutions to its customers for more than 60 years. The company prides itself on offering rugged, cutting-edge equipment to manage difficult-to-process materials across the mining, resource recovery, bulk processing and foundry industries. 

Welding operator welding on large piece of vibrating equipment with another person grinding
Ensuring that the welding operators liked the Bernard guns and AccuLock S consumables was a critical part of the testing General Kinematics conducted.

A reputation for design leadership and creating tailored technical advancements sets the company apart from the competition, as does its commitment to providing excellent service. 

This 200-person, Crystal Lake, Ilinois-based company doesn’t have time for slowdowns, especially in the welding operation. In recent years though, General Kinematics noticed exactly that. It was experiencing repeated MIG gun breakdowns and excessive contact tip consumption that slowed production. 

“Between costs and repairs and lost labor from the welders having issues that stopped their progress, we estimated around $45,000 a year in costs from these issues,” said Jason Jerik, plant manager at General Kinematics.

That’s when Jon Strug, the company’s maintenance tech, approached their welding distributor, Steve Schuette of Weldstar in Aurora, Illinois, for a solution. Schuette recommended a trial of Bernard BTB air-cooled MIG guns with AccuLock™ S consumables. 

Subscribe to the Amperage enewsletter to have more articles like this on delivered to your inbox.

Considering the change

Problems with the water-cooled MIG welding guns at General Kinematics were at the heart of its need for a new solution. 

“The guns were definitely our main issue with maintenance for Jon,” said Joel Jacobson, director of manufacturing. “It was tough to keep up to the demands of the hoses breaking, the wires breaking internally in the guns, tips burning out, liners and such.” 

Jerik added, “The last time we calculated from a dollar standpoint it translated to about five to seven hours a week in lost time just with liner issues. It was that frequent.”

The team, along with Schuette, took a slow and thorough approach to testing the Bernard air-cooled BTB MIG welding guns and consumables, making sure that the products performed as expected. They worked first with some sample guns in standard sizes and leads and had different welders try them for a week each. 

“We would test a week with one fitter, a week with one welder, and then we’d move them around to see what kind of acceptance we would get with them,” said Jacobson. 

Welding operator welding the underside of a flat piece of metal
General Kinematics welds a variety of materials — from A-36 steel to AR-500 plate — in thickness up to eight inches and on a variety of joints.

General Kinematics welds a variety of materials — from A-36 steel to AR-500 plate — in thickness up to eight inches and on a variety of joints. Welding operators also weld both large and small weldments and use different welding wire diameters. The guns and consumables needed to be versatile enough to manage these jobs and produce the quality needed to adhere to the American Welding Society (AWS) D.1.1 Structural Welding – Steel code. They also had to be the right equipment for the company’s welding operators. 

Jacobson and Jerik regularly met with the welding operators to request feedback during the trial. 

According to Jerik, welding operators saw noticeably less consumable consumption. However, they wanted to change the angle on the neck of guns to gain better access to some difficult joint configurations. They worked back and forth with Bernard to determine a different angle of the neck that suited their needs. 

“We wanted to do a thorough run of testing and vetting out to decide ‘Is this the right product for us? Are we going to get that buy-in from our welding operators?’” he said.  

Family product shot of AccuLock S liner, contact tip, nozzle, power pin, gas diffuser
The Bernard guns and AccuLock S consumables have helped welding operators at General Kinematics achieve approximately 10% more productivity by eliminating downtime.

Ensuring that welding operators liked the MIG welding guns and consumables was a critical part of the testing General Kinematics conducted. The company has a culture of empowerment and wanted its welding operators to be heard and to contribute their opinions. 

“We think it’s important to get our welders involved early in the process,” said Jacobson. “Not everyone likes change, but getting them involved in testing up front can help show the long-term benefits.”

“I’m huge on that,” Jerik added. “I’d rather not force and push a change onto a team. I’d
rather them accept it and make it their own.”

After eight months of testing, processing feedback and making adjustments, General Kinematics made the decision to convert to the Bernard BTB air-cooled MIG guns and AccuLock S consumables.

The benefit of the investment

General Kinematics invested in 400-amp BTB air-cooled MIG guns for its 40 welding operators, as well as several 450-amp Bernard water-cooled guns — all with the same AccuLock S consumables. Bernard built the company a special neck for its water-cooled guns to provide better ergonomic access to typical weld joints, and these guns are the first of their kind ever to be configured with the AccuLock S consumables.  

So, what finally sold General Kinematics on the Bernard products? In short, durability and performance.

Image of the General Kinematics building in Crystal Lake, Illinois
General Kinematics has been providing consistent, on-time and innovative solutions to its customers for more than 60 years.

The reduction in gun maintenance was key. Strug no longer has to contend with leaking water-cooled guns or liner issues that need fixing — and the new guns and consumables are less frustrating for the welding operators, who can now spend more time being productive. 

“We have a whole lot fewer repairs. Before it was constantly, every month, seven guns I had to send out to get repaired or I had to repair them myself,” said Strug. “It’s a huge difference in quality — night and day.”

This durability and performance result from a combination of the rugged construction of the BTB air-cooled MIG guns — which were configured according to the handle, neck, trigger and cables the company needed — and the liner that is part of the AccuLock S consumables system. 

Bernard designed the liner in the system for error-proof replacement by eliminating the need to measure it prior to installation. Instead of the liner loading from the back, like many competitive guns, the AccuLock S liner loads in the neck at the front of the gun and then locks in place so it can be trimmed flush with the power pin. This prevents the liner from being trimmed too short or too long.

“I like the liners,” said Strug. “They last a lot longer and I definitely like the quality of them.”

Over-the-shoulder view of welding operator welding on large piece of equipment
General Kinematics invested in 400-amp BTB air-cooled MIG guns for its 40 welding operators, as well as several 450-amp Bernard water-cooled guns — all with the same AccuLock S consumables.

According to Jacobson, another selling point was that AccuLock contact tips run significantly cooler than the company’s previous ones so there is less consumption and downtime for changeover. 

That’s due to the design of the tip and gas diffuser. Sixty percent of the welding contact tip is buried in the gas diffuser, which protects it from heat damage, and the shielding gas also cools the contact tip tail as it flows through the gun. AccuLock consumables have a tapered design that locks the tip, gas diffuser and nozzle tightly together to further reduce electrical resistance and lower heat buildup. 

Jacobson likes the ability to reduce costs by having equipment that lasts longer. And both the air- and water-cooled MIG welding guns use the same AccuLock S consumables, which helps reduce inventory management. 

The welding operators like that the guns and consumables run cooler and help reduce spatter, so there is less cleanup.  

The long-term benefits

For General Kinematics, making the change to the Bernard BTB guns and AccuLock S consumables is just another way the company commits itself to quality. But there has been more to the conversion than that. 

General Kinematics was able to gain a return on investment in approximately 12 to 14 months. And while there are still labor and equipment costs for gun and consumable maintenance, the conversion has eliminated the $45,000 in extra spending to address previous issues with the water-cooled guns. 

The products have also helped its welding operators achieve approximately 10% more productivity by eliminating downtime. That’s important to the welding operators and to Jerik. 

“When it comes down to it, do these products make their job easier? Do they make them more productive?” 

The answer to both is yes.