AccuLock R Consumables Reduce Downtime in Robotic Welding

In many cases, equipment-based solutions can be a means to gain success in the robotic welding operation. They can mitigate costly risks and eliminate issues that lead to inefficiencies. And often, these issues are related to a small but significant part of the robotic welding process — the welding consumables.

Changing over consumables can be a time-consuming part of maintaining the welding cell, especially if it is done multiple times during a shift. Changeover can also negatively impact productivity and quality if the consumables are installed incorrectly. Unfortunately, given the industry’s current lack of skilled welders, that may be a common occurrence. Welders simply have less experience with proper installation processes. To address this problem, many companies tend to spend more time and money on training and troubleshooting. They may even have to find workarounds to problems in the weld cell as employees get up to speed. All of this occupies resources.

Consumable challenges

Welding consumables — the contact tip, gas diffuser and nozzle — can be a major source of downtime in robotic welding operations, unplanned or planned.

During installation, cross-threading of contact tips by less experienced welders is a common occurrence that can result in unplanned downtime. Cross-threading leads to multiple problems beyond the lost productivity for contact tip changeover.

First, it can negatively affect tool center point (TCP), causing the robot to weld off-seam and create quality issues like lack of fusion or poor penetration. Personnel overlooking the robotic welding cell then need to stop production to address rework and/or scrap the part.

Cross-threading can also create a keyhole, or uneven wear, in the bore of the contact tip. A keyhole the size of only half the diameter of the wire can result in the robot welding off-seam.

Many times, a cross-threaded contact tip will stick inside the welding gas diffuser. Without another gas diffuser readily available, the operator has to make a trip to the tool crib for a new one. Meanwhile the robot is offline and not producing parts. Plus, a company incurs costs for both the contact tip and the diffuser’s replacement.

Companies that invest in power sources with a pulsed waveform capability — particularly in the automotive industry — often schedule planned downtime. Pulse waveforms improve productivity and quality by increasing travel speeds, providing a more consistent arc and reducing spatter. However, the pulsing action of the arc electrically and mechanically erodes the contact tip, leading to faster wear. It is necessary to plan downtime as a preemptive strike against contact tip failures before the chance of associated weld quality issues arise.

Both unplanned and planned downtime cost money and occupy available labor for non-value-added activities — tasks that don’t support throughput and productivity.

There is a new welding consumables technology that can help.

A new consumables solution

To address the issue of cross-threaded contact tips, Tregaskiss designed its AccuLock™ R consumables. The design is intended to support higher throughput, provide a long service life and ensure good weld quality.

The AccuLock contact tip features a long tail that concentrically aligns within the diffuser before the threads engage. The threads are also coarse, so they require minimal rotations to install. This design virtually eliminates the risk of cross-threading and provides three key benefits to the robotic welding operation:

1. It decreases the length of unplanned downtime for retrieving a replacement welding gas diffuser after cross-threading.
2. It reduces quality issues from cross-threading, such as off-seam welds or poor joint penetration.
3. It lessens unplanned downtime for troubleshooting.

The contact tips also have greater mass at the front compared to other designs, along with a taper that mates securely with the gas diffuser. The tapered surfaces ensure optimal conductivity, reduce heat and keep the consumables locked in place. These features — combined with the fact that 60% of the contact tip is buried in the diffuser, away from the heat of the arc — make the consumables last longer. Extending the product life means there is less need for changeovers.

AccuLock R consumables can also address the accelerated wear of contact tips caused by pulsed waveforms. In addition to offering the contact tips in copper and chrome zirconium, Tregaskiss has an AccuLock HDP option. The HDP contact tips last more than 10 times longer than copper tips in pulsed MIG welding applications. As a result, companies can reduce unplanned downtime for contact tip changeover — and make those changeovers faster because of the easy-to-install design.

AccuLock R consumables can be implemented easily. Switching from many other consumables typically doesn’t affect TCP or robotic programming; however, it is best to consult directly with Tregaskiss to confirm this is the case.

For companies that have both robotic welding and semi-automatic welding operations, the AccuLock R consumables can simplify complex inventories. The contact tips are part of a Common Consumable Platform™ and can be used across a wide range of Tregaskiss® robotic and fixed automatic MIG guns, as well as with Bernard® semi-automatic MIG guns (ranging from 200 to 600 amps). This common contact tip can reduce inventory costs and lessens the opportunity for operators to install the wrong consumable. The AccuLock R gas diffuser also has a blue o-ring to distinguish it from other diffusers.

Making the change

When companies find equipment solutions, like the AccuLock R consumables, that help reduce troubleshooting and downtime in their robotic welding operations, opportunities can increase. The ability to improve productivity and quality is at the forefront of those. But there may also be more time available to optimize the weld cell, make positive changes to workflow or material handling and seek out cost savings.In some cases, companies may also uncover issues in the weld cell that were previously masked by frequent contact tip changeovers. Now, however, there is more time address those to generate greater efficiencies in the operation.

In short, with the right consumables, there is more time to focus on reaching improvement targets and increasing throughput — and on implementing training that can help achieve those goals.

Selecting the Right MIG Welding Consumables

MIG welding gun configurators, like the Bernard® BTB semi-automatic air-cooled MIG gun configurator, allow you to choose specific styles or types of consumables to match the demands (amperages and waveforms) of your application.

Selecting contact tips

Know the wire size and type when choosing the size and style of contact tip.

1. Contact tips with coarse threads help speed replacement since they require less turns and they minimize cross-threading.
2. Some consumable systems also feature a contact tip that is buried in the gas diffuser. This keeps it cooler and helps it last longer.
3. For more aggressive welding waveforms, like pulsed MIG welding, choose a more durable contact tip. Chrome zirconium is a good option.

Welding nozzle options

Joint access, operating temperatures and arc-on time are important considerations in choosing the right welding nozzle.

1. Brass nozzles are good for reducing the spatter adhesion in lower amperage applications, but do not perform well at higher temperatures.
2. Copper nozzles are a better choice for higher amperage applications.

MIG gun liner selection

Having the right MIG gun liner helps minimize downtime to address wire feeding issues. It is important that you always trim the liner to the proper length. Consider these tips:

1. Liners are available that require no measurement for error-proof replacement. These liners lock and concentrically align to the contact tip and the power pin without the use of fasteners for smooth wire feeding.
2. When the weld cell has a wire feeder mounted on a boom, front-loading liners help make changing liners faster, easier and safer by eliminating the need to climb up to the feeder.
3. Specialty liners can aid in the feedability of the wire, especially in metal-cored or flux-cored applications.

Note, selecting the same welding consumables across multiple weld cells, when possible, can help with inventory management and can be more cost-effective.

Visit the Bernard® MIG gun configurators

This article is the third in a three-part series discussing how configuring a MIG gun can improve the welding operation, as well as what to consider in the process. Read article one, Configuring a MIG Welding Gun for Your Application and article two, How to Choose MIG Welding Gun Parts.

Common Problems With MIG Welding Consumables and How to Fix Them

MIG welding consumables are a critical but often overlooked part of the welding operation. Unfortunately, without a clear understanding of the problems that can arise with consumables — and the best way to fix them — companies stand to lose productivity, jeopardize quality and increase costs. In some cases, the biggest issue is choosing the wrong consumable for the job.

Consider this real-life example: A company with 90 arcs is using five contact tips per day, per welder — that adds up to 450 contact tips a day. By simply changing to a more robust consumable system, the company could potentially use one contact tip per welder every three to four days. The savings in reduced downtime and purchasing costs in this situation is significant.

So how can companies avoid common pitfalls? A willingness to look at the impact of welding consumables on the overall operation — not just the product purchase price — is key. Training is also a vital part of success. Welding operators and maintenance personnel should know how to properly select, install and maintain consumables and troubleshoot problems when they arise. Or better yet, understand how to prevent them in the first place.

Making sense of welding nozzles

Welding nozzles play an important role in the welding operation, directing shielding gas to the weld pool to protect it from contaminants.

Incorrect contact tip recess within the welding nozzle is among the biggest problems. The more the contact tip is recessed, the longer the wire stickout, which can lead to an erratic arc and increased spatter in the nozzle. It can also negatively impact shielding gas coverage.

In approximately 90% of applications, a 1/8-inch contact tip recess provides the best shielding gas coverage with a welding wire stickout that helps support consistent arc stability.

Using the wrong welding nozzle for the application can cause downtime for changeover due to premature failure. For a standard welding application (100 to 300 amps), a copper nozzle provides good heat resistance. Copper nozzles also resist spatter buildup. For higher-amperage applications (above 300 amps), a brass welding nozzle is the better choice. Brass does not anneal as fast as copper, so the welding nozzle will maintain its hardness longer under higher temperatures.

Choosing the wrong shape and size of nozzle can be problematic. Too large of a nozzle can make it difficult to obtain the joint access needed to complete a sound weld.

Long or short tapered nozzles work well for restricted joints. However, there is an increased risk of spatter buildup due to the narrower bore, which can shorten the consumable’s life. To gain good gas coverage, use a longer nozzle when possible.

Avoiding contact tip downfalls

MIG welding contact tips provide the current transfer to the welding wire to create an arc.

Using a contact tip with an inside diameter (ID) that’s too small can lead to poor wire feeding and, potentially, a burnback. Using a tip with too large of an ID can cause the welding wire and arc to wander.

Every consumables manufacturer has proprietary formulas for gauging contact tip ID and implementing it into their design. Select a high-quality contact tip for consistent tolerances, and match the contact tip ID to the diameter of the welding wire to gain the best electrical conductivity. This happens because the contact tip ID is actually slightly larger than the specified measurement. For example, pairing a contact tip with an ID of 0.035 inch and a wire with the same diameter allows the wire to feed smoothly through the bore, connecting enough to generate a stable welding arc.

The wrong contact tip outside diameter (OD) can also cause problems. For higher amperage applications, use a contact tip with a larger OD to better withstand heat.

Pay close attention to the contact tip material to avoid premature failure. Consider these options:

1. Copper contact tips provide good thermal and electrical conductivity for light- to medium-duty applications.

2. Chrome zirconium contact tips are harder than copper ones and are good for higher-amperage applications. They are also a good option if a company experiences ongoing instances of keyholing — oblong wear on the bore that can lead to an unstable arc and premature contact tip failure.

3. Contact tips are available in the marketplace that feature proprietary materials and design. These tips cost more than copper or chrome zirconium contact tips but have been shown to last more than 10 times as long. They are designed for pulsed, spray transfer or CV MIG welding.

Cross-threading the contact tip is another issue that can lead to downtime. When a contact tip isn’t threaded properly during installation, or if the welding operator introduces dirt or debris to the threads, the gas diffuser can be damaged during installation. This will require replacement and increase costs.

To avoid cross-threading, look for contact tips with coarse threads that install with fewer turns.

Getting it straight about liners

The welding liner has a single and relatively simple purpose: to guide the welding wire from the wire feeder through the power cable to the contact tip. However, it is capable of causing significant problems if it isn’t installed properly.

Trimming a liner incorrectly is the most common installation error. A liner that is too short lessens the support of the welding wire as it passes through the length of the gun. This can lead to micro-arcing or the formation of small arcs within the contact tip. Micro-arcing causes welding wire deposits to build up in the tip, resulting in an erratic arc and burnbacks. In more extreme cases, micro-arcing can cause MIG gun failure due to increased electrical resistance throughout the front-end consumables and gun neck. It may also prompt the welding operator to increase voltage in an effort to rectify poor welding performance, which can cause the gun to overheat.

On the other hand, a too-long welding liner can lead to kinking and poor wire feeding.

When trimming a conventional welding liner, avoid twisting it and use a liner gauge to ensure the proper measurement. There are also consumable systems available that provide error-proof liner installation and require no liner measuring. The gas diffuser locks the liner in place while concentrically aligning it with the power pin and contact tip to eliminate any gaps. The welding operator or maintenance personnel feeds the liner through the neck of the gun, locks it in place and cuts the liner flush with the back of the power pin.

As with contact tips, remember that quality matters when it comes to welding liners. Always select a stiffer liner, so it is capable of supporting the wire as it feeds from the spool through the power pin and the length of the gun.

Final considerations

Paying close attention to MIG gun consumables is important to gaining good welding performance. That means looking at the overall quality of the products being purchased; the manner in which they are inventoried, stored and handled; and how they are being installed. Always follows the consumable manufacturer’s recommendations, and when in doubt, contact their customer service or a trusted welding distributor for help.

MIG Welding Consumables Reduce Wire Feeding Issues and Downtime

When MIG welding consumables aren’t properly installed or maintained, it can result in wire- feeding issues and weld quality problems. Troubleshooting and correcting these challenges can cost hundreds of dollars — and hours per day — in a manufacturing operation.

As the industry faces a shortage of skilled welders and those entering the profession have less experience, it may be more common for welders to incorrectly install MIG gun consumables and liners.

Consumables that simplify the installation process can help eliminate errors, reduce downtime for changeover and troubleshooting, and decrease costs.

Learn how new consumables available in the marketplace can help address wire-feeding problems and the role they play in maximizing throughput and productivity.

The cost of poor consumable performance

Not addressing poor consumable performance can result in, among other problems, lower-quality parts and expensive rework.

Wire-feeding issues are some of the most common complaints in the welding industry. Often, improper trimming or installation of the MIG gun liner is the cause of these problems.

As with other consumables, the MIG gun liner wears out over time and must be changed periodically. Typically, replacement liners are longer than necessary and must be trimmed appropriately for the style and length of the MIG gun. Trimming the liner to the proper length can be difficult. In some cases, the welder may change the liner without taking the time to complete the proper steps of installation or may not know the proper steps.

This can result in a host of problems. A liner that is cut too short can lead to the issues a lot of welders experience: wire chatter, erratic arc and burnback. A too-long liner, which happens less frequently, results in a tight fit and can cause the wire to weave and curve as it feeds through the gun. If the operator continues to weld without diagnosing the cause of any of these problems, it may result in bad welds that require rework or result in scrap.

It seems to be common in the industry that welders typically change the contact tip at the first sign of trouble with the welding gun, and this may help for a short-term fix. But if the liner is the root cause, the problem will repeat itself, leading the welder to use more tips than if a correctly trimmed liner was installed. This increases costs due to wasted consumables and downtime for changeover.

In some operations, welders don’t install or trim liners. Instead, MIG guns are taken to a maintenance department whenever a liner must be changed. This adds downtime and costs and decreases throughput in the operation.

Error-proof liner replacement

Solutions that are designed to address liner trim length errors and poor wire feeding can reduce troubleshooting, downtime and rework — ultimately saving money. 

The AccuLock™ S consumables system from Bernard^® take the guesswork out of liner trimming and installation in semi-automatic welding operations. The system offers an error-proof liner replacement process that eliminates measuring and incorrectly trimming liners.

In contrast to most MIG gun liners that load from the back of the gun, AccuLock S liners load through the neck at the front of the gun. The liner is then locked and trimmed flush with the power pin at the back of the gun, which eliminates the need to measure.

This design also eliminates doubt about proper liner length — and the time spent troubleshooting liner trimming issues — because operators can simply look at the back end of the gun to see that the liner is correctly trimmed and in place.

With traditional MIG guns, welders can’t see if a liner is cut too short, since the end of the liner that’s been trimmed is hidden under the nozzle and gas diffuser. A welder would have to remove all the consumables to see the liner inside the gun.

Optimize wire feeding

In addition, the system optimizes wire feeding because the liner is locked and concentrically aligned to both the contact tip and the power pin without the use of fasteners. Capturing the liner at both ends of the gun keeps the liner from extending and contracting based on gun position — and it allows for a flawless wire-feeding path.

Typically, the longer the welding gun, the more the cable bends and twists. Even when a traditional liner is perfectly cut and installed, the liner gets pushed forward and back inside the gun as it’s used, since the liner is affixed at the back end of the gun but free floating at the front end of the gun. This liner movement can result in wire chatter and erratic arc.

When the liner is affixed at both ends of the gun, as with the AccuLock S consumables system, 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.

And because the liner is concentrically aligned with the contact tip, it creates less mechanical wear on the tip’s interior diameter, possibly leading to longer life by reducing the risk of keyholing associated with misaligned liners and contact tips. Reducing keyholing also lessens the opportunity for an erratic arc, excessive spatter and burnback, all issues that shorten contact tip life.

Maximize performance and life 

Additional features of the new consumables system also contribute to optimized MIG gun performance:

Cool, connected contact tip: Sixty percent of the AccuLock 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, which helps reduce heat and wear. These features differ from traditional tips that screw onto the gas diffuser with little to no portion of the contact tip exposed directly to the shielding gas as it exits the diffuser to the arc. A tapered design of the consumables tightly locks the conductive parts together to minimize electrical resistance and further reduce heat buildup.

Versatile nozzle: A patent-pending nozzle design allows operators to choose thread-on or slip-on — with the same nozzle part number. Typically, nozzles are either thread-on or slip-on style, a choice that often comes down to welder preference. A thread-on nozzle is locked in, while a slip-on nozzle can be adjusted to different heights and easily pulled off.

With AccuLock S consumables, the same nozzle can be used as a slip-on or thread-on nozzle, and the change is determined by using a different diffuser. This allows operations to greatly simplify their consumables inventory and changeover, with fewer parts to manage. In addition, a steel retaining ring and friction lock on the diffuser help prevent the nozzle from unthreading or loosening when it’s threaded on. This also helps eliminate the potential for gas leaks at the back of the nozzle or insufficient gas coverage of the weld — a common occurrence when traditional thread-on nozzles loosen over time.

Coarse threads: The AccuLock contact tip features coarse threads, making it less likely to become cross-threaded and also requires fewer turns to install or remove — speeding up tip replacement. One full turn disengages the contact tip from the diffuser.

Reduce wire-feeding and weld quality issues

Significant time and money can be spent troubleshooting weld quality problems and wire- feeding issues, such as erratic arc, bird-nesting and burnback. In addition, many welding operations are dealing with increasing welder retirements and turnover, which can increase troubleshooting time associated with less experienced welders installing consumables.

The AccuLock S consumables system is designed to eliminate liner trimming errors and optimize wire feeding to help operations reduce downtime, costs and rework — maximizing throughput and efficiency.

New HDP Contact Tips Provide Robotic Pulsed MIG Welding Benefits

Optimizing the robotic weld cell helps improve productivity, allowing a manufacturing facility to save time and money. It can be especially beneficial in applications that use pulsed gas metal arc welding (GMAW-P), a process that results in rapid wear to the welding gun’s front-end consumables.

While the choice of contact tip for the GMAW gun may seem like a small factor in the entire operation, consider how much time it takes for an operator to enter the weld cell and change the contact tip — and how many times per day the tip is changed in most robotic welding operations. For example, copper contact tips are changed on average four times per shift. In a three-shift operation averaging 10 minutes per tip change, that equates to spending two hours per day changing contact tips. What else could a welding operator be doing with this time to create value in the manufacturing operation?

There are contact tip innovations that help significantly reduce the downtime spent on changeover — time that can be spent on other tasks in the operation, such as increasing production up-time. In addition, when the operator spends less time in the weld cell, it reduces the potential of health and safety incidents and the possibility of weld quality issues through altering weld settings and parameters such as tool center point.

For these reasons, it’s important to consider the total cost of ownership when selecting the right contact tip for a robotic welding operation.

Demands of GMAW-P

As more manufacturing applications use thinner, lighter and more corrosion-resistant materials to meet industry demands, this increases the use of GMAW-P processes, which offer benefits for welding thin-gauge materials. Pulsed waveform technology continues to develop, offering faster travel speeds, reduced spatter levels and high weld quality in many robotic applications.

However, pulsed processes typically require a higher frequency of contact tip changeover due to the energy of the process. Faster contact tip deterioration is caused by peaks in pulse waveforms where the energy/heat is five times greater than in traditional constant voltage (CV) GMAW.

Because of this, arc erosion is a common failure for contact tips in GMAW-P. Contact tip failure increases an operation’s costs, due to the increased frequency of downtime related to tip changeover.

A new contact tip design has resulted in tips with improved resistance to arc erosion that last much longer in pulsed welding.

Contact tip advancements

Contact tips made from copper or copper chrome zirconium are commonly used in many welding applications. However, adoption of a GMAW-P process can double contact tip replacement frequency and related downtime when using copper or chrome zirconium tips.

A new innovative technology on the market today can significantly extend the time between contact tip changeover, thanks to a combination of proprietary materials and tip design. HDP contact tips from Tregaskiss last more than 10 times longer than copper or chrome zirconium tips, allowing operations to go from changing contact tips two to four times each shift to only changing the tips once every third shift or longer.

HDP contact tips are engineered to resist wear better than other materials and designs previously used for contact tips, providing increased resistance to arc erosion in pulsed welding, as well as spray transfer and CV GMAW. The precise fit between the tip and the wire also results in good arc stability to help produce high-quality welds, and because the degradation of welding current from the power source to the contact tip is reduced, it provides a truer representation of the pulsed waveform program.

The tips currently come in .035, .040 and .045 sizes and can be used with standard nozzles and TOUGH LOCK® retaining heads as well as with air-cooled guns or water-cooled guns. HDP contact tips can be used with Tregaskiss guns, as well as guns from other MIG welding gun manufacturers.

Because the tip bore is sized so tightly to the welding wire, it’s best to use the HDP Contact Tip with good-quality welding wire that has a large cast. A high-quality wire typically has a consistent wire diameter, which promotes better feeding and optimized performance.

Significant productivity gains

Typically, operations conduct contact tip changeovers on a preventive maintenance schedule to avoid unplanned downtime in the manufacturing process. The necessary frequency of contact tip changeover varies based on many factors including application, wire type and quality, waveform and base material.

Many robotic welding operations have 100 welding arcs or more and run three shifts per day. In robotic welding operations, copper tips are changed on average four times per shift — or 12 times per day. Chrome zirconium tips are changed about half as often, or six times per day. A scheduled contact tip change typically takes 10 to 15 minutes to complete.

Compare this to real-world results from several manufacturing operations using HDP contact tips. For example, one manufacturing operation converted to HDP contact tips in a solid wire GMAW-P application. The operation produces 600 parts per shift, and the previous chrome zirconium contact tip required changeover every 60 to 80 parts — or about 10 times per shift. In the company’s trial, one HDP contact tip was still running after 2,500 parts under the same parameters.

Another manufacturing operation running a standard GMAW process tried HDP contact tips on a line of 18 robots. Where previous contact tip usage for the operation was 216 per day — or about 1,500 tips per week — one HDP contact tip lasted an entire week on each cell, totaling 18 tips per week.

Additional benefits

In addition to the significant productivity gains the new contact tip design provides, there are other benefits for arc stability, productivity and operator safety.

Reduced frequency in contact tip changeover not only increases throughput while saving time and money due to downtime, it also reduces the risk of safety incidents, since every time an operator enters the weld cell it increases the risk of injury.

Also, each time someone touches the welding gun, there is the risk putting it out of alignment. The less frequently an operator must enter the cell, the less chance there is for human error that can disrupt tool center point that reduces part quality.

Frequently changing the contact tip can cover up other issues within the weld cell. When the contact tip is changed less often, other issues such as wire feeding problems, wire routing or a loose ground can come to the forefront. With standard contact tips, changing the tip out is often the first go-to fix when there is a problem in the weld cell — even if something else is the root cause. With a longer-lasting contact tip that is not changed as frequently, other issues that may not have been noticed before can now be fixed to improve the overall efficiency of the weld cell.

Return on investment

It’s important to consider total cost of ownership when evaluating contact tips and other consumables. The upfront cost of a contact tip is just one factor in total overall costs. A longer-lasting contact tip may be more expensive upfront, but it can provide significant payback in time and labor savings and reduced downtime.
Be sure to look at the big picture in terms of productivity and efficiency improvements for the entire operation.

In considering a switch in consumables, an operation should also be sure there is time to conduct a trial, which should always be part of changing the type of consumable or contact tip. The numbers will often speak for themselves when vetting the option and analyzing return on investment.

Improve productivity and efficiency

An operation may think the welding process is optimized, but that may not be the case if operators must frequently enter the weld cell to change the contact tip. As manufacturing operations look for ways to improve production efficiency and throughput in automated welding, choosing the right contact tip for the gun is one solution.

A contact tip designed to provide significantly longer tip life saves time and money in necessary changeover and reduces the frequency of people entering the weld cell. New contact tips on the market can last days in GMAW-P applications compared to standard copper tips that may only last a few hours.

 *Other parameters: 450 ipm wire feed speed, 40-45 ipm travel speed, 90/10 mixed gas, 240-260 average amps on a Tregaskiss robotic MIG gun with a 22-degree neck.