Light- or Heavy-Duty? Which Semi-Automatic MIG Gun is Right for the Job?
When it comes choosing welding equipment, welding operators may find themselves first and foremost contemplating which power source to use. And rightly so. The power source has a significant impact on weld quality, productivity and the overall cost of the welding operation. But having the right semi-automatic MIG gun for the job is equally important.
From short arc-on times for tacking parts to completing long continuous welds on thick plate, the MIG gun needs to offer the appropriate welding capacity for the job. For example, welding operators may not need a MIG gun that is the same amperage as the power source. That is because often they weld only 30 to 50 percent of the time, making the use of a lower amperage gun an appropriate option. Conversely, when welding operators overwork a light-duty MIG gun it could lead to premature failure. Or, in some cases, the welding operation may have multiple applications, making it necessary to have a MIG gun that can address the needs of several applications within one facility.
On the Lighter Side
For welding applications that require short arc-on times, such as tacking parts or completing welds on small parts, a light-duty MIG gun may be the best choice. A light-duty MIG gun is typically considered one that provides from 100 to 300 amps of welding capacity. Like all MIG guns, light-duty ones are rated according to their duty cycle, or the number of minutes in a 10-minute period that the gun can be operated at its full capacity without overheating. Generally, MIG gun manufacturers rate their products at 60 to 100-percent duty cycle. In the case of light-duty applications, including welding sheet metal, general hobbyist projects, or auto repair and auto body applications, a light-duty MIG gun would work well.
Because light-duty MIG guns typically offer low amperage capacity, they also tend to be smaller and weigh less than higher duty ones, making them easy to maneuver even in tight areas. Most have small, compact handles as well, so they are comfortable for the welding operator to use.
Light-duty MIG guns often use light or standard duty consumables—nozzles, contact tips and retaining heads (or gas diffusers). These consumables generally have less mass and are less expensive than their heavy-duty counterparts. Similarly, because they are designed for short arc times, the necks (or goosenecks) on light-duty MIG guns are made of lightweight materials, including polymer, rubber or light aluminum armor.
The strain relief and connections on light-duty guns are also unique. In particular, the strain relief is usually composed of a flexible rubber component and in some cases may be absent all together. These features help maintain the gun’s light weight, but they can allow for kinking that may lead to poor wire feeding and gas flow.
Finally, some unicables on light-duty MIG guns have crimped connections and may not be able to be repaired. If a crimped cable becomes damaged, the cable or possibly the entire gun may need to be replaced.
As a rule, light-duty MIG guns offer standard features at a lower price and typically need to be replaced more frequently.
For the Tougher Jobs
On the opposite end of the spectrum from the light-duty applications and MIG guns previously described are jobs that require long arc-on times and/or multiple-passes on thick sections of material. These applications include ones found in heavy equipment manufacturing for the agriculture, construction and mining industries, over-the-road trailers and trucks, and other similarly demanding welding jobs. For these applications, heavy-duty MIG guns are the best choice, as they can be used for continuous welding on one inch or thicker material and in harsh environments typical to such industries.
Heavy-duty MIG guns generally range from 400 to 600 amps and are available in both air- and water-cooled models. Choosing between a water- or air-cooled heavy-duty MIG gun largely depends on welding application, operator preference and cost considerations. Water-cooled systems are more expensive and often require more maintenance. Specially treated coolant solution, rather than tap water, is necessary for a radiator cooling system because tap water can cause algae growth or scale (mineral buildup) on the internal gun surfaces and cable assembly. In addition, over time water can leak from hoses, the gun neck or heads, requiring immediate repair to prevent weld discontinuities and gun failure. However, despite the additional cost, when welding on very thick plate that requires high deposition and good weld penetration, a water-cooled heavy-duty MIG gun may be required.
Heavy-duty MIG guns—both air- and water-cooled models—often have larger handles than their light-duty counterparts in order to accommodate the guns’ larger cables (due to the higher amperage being provided). Heavy-duty MIG guns often use heavy-duty front-end consumables that are capable of withstanding high amperages and longer arc-on times. The goosenecks on these guns are often longer as well, which puts more distance between the welding operator and the high heat output from the arc. Most goosenecks for heavy-duty guns are generally comprised of aluminum armor that protects it from damage from the high temperatures, plus day-to-day wear and tear. The addition of a heat shield is an option to protect the welding operator from the heat output of a high amperage MIG gun and longer arc-on time. This heat shield provides a barrier between the arc and the welding operator’s hand. Adding a unicable cover can help protect the power cable from a harsh environment, too.
Heavy-duty MIG guns often feature locking triggers, as welding operators use these guns for multiple weld passes and/or long continuous welds and these types of triggers help prevent fatigue. Other heavy-duty MIG guns feature dual- or multi-schedule triggers that can be mounted on the top or the bottom of the MIG gun according to the position that the welding operator finds most comfortable.
Heavy-duty MIG guns can also, in many cases, be customized to meet the needs of the application at hand. Some MIG gun manufacturers allow welding operators to configure a heavy-duty MIG gun according to their preferred handle style, gooseneck length and angle, and unicable length.
Parting Thoughts
Remember, just like any part of the welding process, MIG guns play an important part in obtaining the quality and performance desired for a given application. Overusing a light-duty MIG gun can easily result in poor performance, while using a heavy-duty MIG gun without cause can increase the cost of the welding operation unnecessarily. If a company has multiple power sources guns can be standardized to fit them through the addition of a feeder adapter. Doing so allows for one common MIG gun to be used throughout the operation, lessening the need to inventory multiple styles of guns and consumables.
Ultimately the goal is to accommodate both the amperage and duty cycle of the application in the best way possible. And even more so, the selection can also conserve the resources of the welding operation and aid in achieving high productivity.
Good GMAW Welds Begin with Good, Well-Maintained Equipment
Good GMAW Welds Begin with Good, Well-Maintained Equipment
It might at times seem like alchemy, but in fact there is nothing mysterious or magical about making a good GMAW weld. A good weld is the result of properly functioning equipment, good technique and the correct equipment settings for the application at hand. Like a tripod, if any of these three elements are not in place, the result will almost certainly be a poor weld.
On the equipment side, the MIG gun and consumables are often overlooked as a critical element in the process of producing a high quality weld. However, being the most handled pieces of equipment and the closest to the point of the arc, the gun and consumables are exposed to continual mechanical and heat stress.
Two critical elements to ensure the gun and consumables do not interfere with your ability to produce high quality GMAW welds are proper gun maintenance and correctly troubleshooting problems when they arise.
Maintaining Your Equipment
Thankfully, GMAW guns and consumables don’t require a lot of time consuming maintenance and upkeep. Nevertheless, failing to spend a small amount of time maintaining your equipment could result in spending a significant amount of time reworking bad welds.
The majority of gun and consumables maintenance simply involves checking the visible components of the equipment for problems. This includes for looking loose fittings, damaged cables, clogged diffuser ports and the like.
Below is a component-by-component guide to minimize downtime for reworking bad welds.
Feeder Connection — The feeder connection, which carries the electrical current and gas from the wire feeder to the gun, should be tight fitting and free of excessive dirt and debris. The O-rings that ensure the shielding gas flows into the gun cable and nowhere else, should be in good working order, ie: not dry, cracked or otherwise damaged.
If the feeder connection is loose and cannot be properly tightened, it will likely need to be replaced. The same goes for damaged O-rings. A dirty direct plug usually can be cleaned with an electrical contact cleaner.
Cable — Cable maintenance involves little more than inspecting it on a daily basis to ensure there are no cuts, kinks or other damage that could interfere with weld quality and also cause a safety hazard.
Avoid problems such as porosity, an erratic arc and damage to the copper cable stranding by keeping the cable from bending at too severe of an angle.
Liner — Accessing the liner can be very time consuming, so you should limit routine maintenance activity to periods when the liner is easily reached, such as during wire changeovers or when the gun is disconnected from the feeder. You can clear out any built up debris, including metal filings from the welding wire, by using compressed air during these changeover times.
Handle and Trigger —Daily visual inspection should be conducted to ensure there are no missing screws or other damage to the handle and that the trigger is not malfunctioning. These items should be replaced as necessary if they are found to be damaged.
Neck — The neck connections, and the insulators that separate electrically live components from neutral components, should be checked on a regular basis as both a safety and weld quality measure.
Loose neck connections should be tightened or, if damaged, replaced. You should also check that the insulators are in place at either end of the neck and that they are undamaged.
Consumables — Consisting of the diffuser, nozzle and contact tip, the consumables require regular replacement simply by virtue of their role in the welding process and proximity to the arc. Extending the life of the consumables is relatively easy, however, and you can save a significant amount of downtime and equipment costs through some simple maintenance steps.
Multiple times daily, use a welding pliers or reamer to clear out any spatter or other debris that could clog the nozzle and diffuser, being careful not to damage these parts in the process.
Also, you should check the O-rings on the diffuser, the connections between the diffuser, neck and contact tip, the nozzle insulator and the contact tip on a daily basis. Loose connections can usually be tightened, but you should replace these components if any other types of damage appear.
Troubleshooting
Of course, no amount of preventive maintenance will be able to stop every problem from occurring. So, when a problem does arise, it’s important to be able to identify and correct its cause.
Often, the same problem, such as erratic wire feeding, can have more than one cause. In these cases, it’s usually a good idea to conduct the troubleshooting effort by working from the easiest component to check to the most difficult.
For example, both the liner and the contact tip can be the source of erratic wire feeding. The liner takes approximately 20 times longer that the contact tip to check, so it makes sense to begin with the contact tip and only check the liner if necessary.
Below are a few of the most common problems that occur as a result of gun and consumables malfunction.
Wire does not feed — If your wire is not feeding at all, it is most likely being caused by a faulty feeder relay, control lead, adapter connection, liner or trigger switch.
If the drive rolls are not turning when the gun trigger is pulled, it is either because an electrical continuity failure is occurring at the gun connection or the trigger is not functioning properly. Repair or replace any of these items discovered to be the cause of the problem.
If the drive rolls turn, but the wire is not feeding, there may be inadequate drive roll pressure or a blockage in the contact tip or liner. As mentioned earlier, check the contact tip and drive rolls before proceeding to the liner.
Consult the manufacturer of your wire feeder if the feeder relay turns out to be the cause of the problem.
Contact tip burnback — Contact tip burnback, when the wire fuses with the contact tip, occurs occasionally as a normal part of welding. If you are noticing an increase in burnback frequency, it could be a result of using the wrong contact tip recess, holding the gun too close to the workpiece or a faulty work lead.
If you have not changed your welding parameters, shielding gas and base metal, then it’s unlikely the contact tip recess is the cause of the problem. Additionally, if those variables are the same and you are confident you are not welding any closer to the material than normal, it may be time to consider the work lead as the cause of the burnback. Repair or replace a faulty work lead as necessary.
A final cause of increased burnback, erratic wire feeding, is discussed below.
Erratic wire feeding — If the wire is not feeding from the gun at a consistent rate, it is most likely being caused by the liner, drive rolls or contact tip.
Begin troubleshooting an erratically feeding wire by ensuring the contact tip is the correct size for the wire being used, and that it is not damaged from excessive wear by the wire or from heat exposure from the arc.
If the contact tip is worn out from excessive wear, it could be a result of the drive rolls causing small deformities in the wire. After replacing the contact tip, be sure to check for burrs or other abnormalities along the length of the wire and adjust or replace the drive rolls as necessary. Drive rolls that are improperly tensioned, either too tight or too loose, can also lead to erratic wire feeding.
Erratic arc — Interruptions in electrical conductivity are often the primary cause of an erratic arc. These are commonly caused by the wire maintaining only intermittent contact with a worn out contact tip instead of the constant contact required for a consistent arc. Simply replace the worn out contact tip with a correctly sized new one if this proves to be the case.
Other possible causes of an erratic arc, all of which relate to inconsistent electrical conductivity, are a neck that is too straight, a worn or kinked liner, debris built up inside the liner, an improperly trimmed liner and a faulty work lead connection.
Porosity — Holes in the weld bead, called porosity, are almost always caused by problems with the shielding gas coverage. This can be caused by excessive wind blowing the shielding gas away, worn out or damaged diffusers, insulators, o-rings and fittings, a ruptured gas hose, too much or too little gas flow or a faulty solenoid.
If porosity occurs without any changes to your work environment and equipment set-up, troubleshoot the problem by checking all of the above mentioned components and replacing as necessary.
Good GMAW welds are not a product of luck, and poor welds can usually be attributed to operator technique, equipment malfunction or incorrect electrical parameters. Following these maintenance and troubleshooting tips won’t ensure excellent GMAW welds, but it will guarantee that your gun and consumables are not the cause of any problems that arise.
Today, more companies than ever are automating portions, if not the entirety of their welding operations. The reasons are many: to address the welder shortage, improve quality, decrease waste and rework, and/or to increase productivity. Not all companies that attempt the automation journey, however, are successful. In fact, those that begin without a well-thought-out roadmap are risking valuable time and investments and are likely to miss the full benefits of welding automation. On the other hand, companies that begin with a careful examination of their welding needs and current processes—including an accurate assessment of workflow and an evaluation of the potential return on investment (ROI) and develop a detailed plan with clearly established goals are likely to achieve welding automation success. On average, labor accounts for approximately 70 percent of any welded part’s cost. An automated system has the potential for reducing that cost, as a robot can typically do the work of two to four people, operating without attention deficits or bad days. Companies cannot, however, simply purchase an automated system and let it go. A skilled welding operator is needed to program the equipment, which may involve additional training to upgrade his or her skill sets, and may also require alleviating this welding operator of some existing tasks. With the right automated system, a company can significantly improve first-pass weld quality and reduce the need for scrapping or reworking parts. It can also minimize or eliminate spatter, which in turn reduces the need to apply anti-spatter or perform post-weld clean up—both labor-intensive processes. Plus, if a company currently has personnel applying anti-spatter, it may be able to free up that manpower for other, more productive uses elsewhere. An automated system can reduce overwelding, a common and costly occurrence associated with the semi-automatic process. For example, if a company has welding operators who weld a bead that is 1/8-inch too large on every pass, it can potentially double the cost of welding (both for labor and for filler metals), and over-welding may adversely affect the integrity of the part. Automation can prevent this problem. Finally, robots are fast. They don’t have to weld all day to be profitable; they only have to weld more quickly than a manual welding operator—and they do. That fact increases productivity, and creating the same number of parts in a shorter time also decreases labor costs and raises profitability. While these benefits may immediately beg the question, “How can our company automate?” there are a few questions that need to be answered first. One of the first things to ask when considering welding automation is this: “Does the company have a blueprint, preferably an electronic blueprint, of its parts?” If it doesn’t, it probably won’t meet the basic criterion necessary to ensure the part is repeatable, and repeatability is the key to automation. An automated system, whether robotic or fixed, needs to weld in the same place every time. If a part’s design is unable to hold its tolerancesif there are gap and/or fit-up issuesthe company will simply be automating a broken process, which in turn, can lead to increased rework and scrap. If a company currently relies on its welding operators to compensate for fit-up issues, it will need to look upstream in the manufacturing process to ensure consistency. What processes will need to change to make sure uniform parts are sent downstream by these welding operators? Or, if vendors supply the components, can they guarantee that consistency? There is no single automation solution that is best for every company. The best solution will depend on many factors, including the expected lifetime of the job, the cost of tooling involved and the flexibility offered. Fixed automation is the most efficient and cost-effective way to weld certain components, such as those requiring simple repetitive straight welds or round welds, where the part is rotated on a lathe. For a company that wants to redeploy the asset when the current job ends, however, a robotic welding system offers more flexibility. A robot can also hold programs for multiple jobs, so, depending on volume, it may be able to handle the tasks of several fixed-automation systems. There is a certain volume of parts that will justify the investment of automation for each company, and an accurate assessment of goals and workflow can help determine what that volume is. If a company makes only small runs of parts, automation becomes more challenging. If, however, a company can identify two or three components that can be automated, a robot that can be programmed to recognize those parts can offer greater flexibility and may benefit even small fabricators who may not have significant volume of a single part. Although a robot is more expensive than a fixed-automation system, companies should be sure to consider the cost of the necessary tooling before deciding between the two. Fixed automation systems can become quite expensive if extensive changes are required to retool a part to ensure it can be welded consistently. A streamlined workflow is one of automation’s benefits. To achieve it, however, it is necessary to look beyond the weld cell to ensure your facility can accommodate a smooth flow of materials. It would make little sense, for instance, to invest in an automated system to increase your productivity and then place it in a corner where each part has to be handled twice. Companies should have a dependable supply of parts in order to avoid moving a bottleneck from one area to another and should also look at the expected cycle time of the robot. Can personnel supply parts to keep up with the demand of the automated system’s cycle time? If not, the supply of parts, including where they are stored and how they are moved, will need to be adjusted if automation is to be successful. Otherwise, a robot will sit idle waiting for components to come down the line—a costly and counterproductive state for a company to find its automated welding system. Companies will need to have the right power and gas systems in place or factor in the cost of implementing these systems. To move to an automated system, a facility needs a 480-volt, three-phase power supply, as well as bulk delivery of gas and wire. A gas manifold system may add to the initial cost of automation, but will minimize downtime for changing gas cylinders in the long run. Determining who will oversee the automated system and providing training is also essential. Most robot OEMs offer a weeklong training course explaining how to operate the equipment. This course, followed by a week of advanced programming, is recommended. Because there is more to welding automation than simply purchasing a robot, partnering with a competent integrator or automation specialist can help ensure success. The automation specialist will… Remember, there is no single path to successful welding automation. Still, a well-thought-out plan that includes accurate evaluations is a good start to the journey. Robotic welding systems introduce speed, accuracy and repeatability into the fabrication process. The repeatability of these systems can increase productivity and reduce welding production costs, thereby maximizing the return on the investment in automation. When compared to semi-automatic welding operations, a robot has the ability to perform the same or more tasks, with extreme precision and a lower labor cost per part. Still, achieving these results isn’t subject to chance. It’s the result of careful equipment purchases, software programming and operator training. In many cases, it can also be the result of complementary equipment called peripherals. Peripherals are any equipment integrated into the robotic welding process with the objective of maximizing its effectiveness and protecting the overall equipment investment. In short, these devices (in most cases) can add significantly to the ROI a company achieves with its welding robot. The key to successful peripheral selection and usage, like that of any other equipment, is simply a matter of education. All robotic welding systems require some form of collision detection in order to reduce the damage to both the robot and the welding system in the event of an impact. Impacts occur for several reasons. These include a robotic gun colliding with an incorrectly positioned work piece or tooling that has been left out of position, or striking an item that has inadvertently been left in the weld cell. Depending on the type of collision detection utilized by the particular robot manufacturer, it will require either a shock sensor or safety clutch as protection. In cases where collision detection is integral to the robot, a solid mounting arm can be used. The sensitivity of a clutch or shock sensor can be calibrated to accommodate the robotic welding gun’s mass and moment of inertia. The function of a clutch is both mechanical and electrical. The clutch first recognizes the physical impact of the torch on a solid surface, which sends an electrical signal back to the robot controller, causing the system to stop. This action prevents damage to the robot and the robotic gun. It also alerts the welding operator overseeing the operation that there is an incorrect variable in the weld cell. Some robotic systems are capable of monitoring current rates and/or torque via robot collision detection software that stops the robot in the event of an impact. In this situation, a solid arm mount would be used in lieu of a clutch. As its name implies, a solid arm mount is just that: solid. It does not provide electrical feedback during an impact, but rather relies on the software to stop the robot during an impact. Both clutches and solid arm mounts require mounting arms that attach them to the robotic MIG gun. A mounting arm is generally composed of a durable aluminum alloy that can resist breakage during an impact. Its purpose is to hold the robotic MIG gun in a specified position (even after a welding operator replaces the gun), so the robot can repeat the same weld throughout the welding process. Clutches and solid arm mounts are also quite robust and require little to no maintenance to keep them operating to their fullest. However, should a company feel that maintenance or repairs are necessary for one of these peripherals, maintenance personnel should contact their welding distributor, integrator or robotic equipment manufacturer for advice. For companies whose robotic welding applications require consistent welding wire stick-out (the distance the wire extends from the end of the contact tip) when the arc initiates, a wire cutter is recommended. Note, consistent welding wire stick-out is not required for all applications. Again, as its name implies, a wire cutter cuts the welding wire to a specified length or stick-out and/or it also removes any balling at the end of the wire. In doing so, this peripheral helps provide smooth arc starts. It also helps attain reliable, repeatable welds, as many companies who own automated systems program the robot to seam track, or find the joint, with touch sensing. This touch sensing depends on the robotic MIG gun having a consistent length of wire with which to locate the correct spot and begin welding. Another key peripheral is a neck (or gooseneck) inspection fixture. A neck inspection fixture tests the tolerance of a robotic MIG gun’s neck to the tool center point so it can be readjusted after an impact or after bending due to routine welding. Most inspection fixtures will accommodate standard necks for that particular brand of robotic gun. They are designed with a precision-tooled steel base to withstand the harsh robotic welding environment and also to guarantee accuracy after long-term use. The advantage of adding a neck inspection fixture to a robotic weld cell is two-fold. One, it ensures the neck meets the specifications to which the robotic welding system has been programmed. Once the tolerance has been determined, a trained welding operator simply adjusts the neck accordingly. This adjustment helps prevent costly rework due to missing weld joints. Accurate neck adjustments also prevent the downtime necessary to reprogram the robot to meet the welding specifications with the existing bent neck. Secondly, a neck inspection fixture can save companies time, money and confusion when exchanging necks from one robotic MIG gun to another. This is especially advantageous for companies that maintain a large number of welding robots. Welding operators can simply remove a bent neck and change it with a spare that has already been inspected and adjusted, and put the robot back in service immediately. The damaged neck can then be set aside for inspection while the robot is still online. This again lowers downtime and also helps companies save money for extra parts. One of the most important peripherals a company should consider for its robotic welding system is a nozzle cleaning station, also called a reamer. This peripheral can be used by itself or in conjunction with a sprayer that applies anti-spatter compound. A nozzle cleaning station cleans the robotic gun nozzle of spatter and/or clears away debris in the diffuser that accumulates during the welding process. If a sprayer has been mounted on the nozzle cleaning station, it will apply a water- or oil-based anti-spatter compound to protect the nozzle, diffuser and work piece from spatter after it has been cleaned. Again, there are several benefits a nozzle cleaning station can have on the robotic welding process. First, by minimizing the accumulation of spatter and debris in the nozzle, it helps lengthen the life of the robotic gun consumables (nozzle, contact tip and diffuser), and of the robotic gun itself. This longer equipment life translates into less downtime and labor for component changeover and also less cost for equipment—both factors contribute positively to a company’s ROI of its robotic welding system. A clean nozzle also helps provide better weld quality and reduce problems that could lead to rework. To achieve all of these benefits, it’s important to consider two factors: one, the location of the nozzle cleaning station, and two, the timing of its use. Ideally, the nozzle cleaning station should be placed in close proximity to the welding robot so that it is easily accessible when cleaning is necessary. As well, the nozzle cleaning process should be programmed so that the function occurs in-between cycles—during part loading or tooling transfer. In this case, the cleaning time would not be added to the overall cycle time per part, as a typical nozzle cleaning station needs only a matter of three or four seconds to complete the job. If a company attaches a sprayer to its nozzle cleaning station, it should be certain to use only the minimum amount of anti-spatter compound required for the application. Excessive anti-spatter usage can lead to unnecessary costs and the compound may build up on the nozzle, the welding robot and the parts being welded. In the long term, a high spray volume could cause additional problems that are just as bad as spatter build-up itself. Finally, implementing a preventative maintenance plan for a nozzle cleaning station is imperative to gaining long-lasting results from the equipment. And it’s easy. Simply clean off the peripheral, wiping it free of dirt, debris and/or spatter, on a weekly basis to prevent malfunctions, and in turn, quality issues in the robotic weld cell. The decision for a company, large or small, to invest in robotic welding equipment is significant. It requires time, knowledge and a trusted relationship with a robotic welding equipment manufacturer and/or integrator to find the right system for the application. The same holds true for peripherals. And although these devices do add to the initial cost of automating, they can lead to measurable cost savings and profits in the long term. Remember, the goal in robotic welding is repeatability and increased productivity, any additional equipment that can help achieve that result is worth the consideration. Many manufacturers believe that converting their semi-automatic welding processes to a fast, productive, fully automated process is simply a matter of deciding to do it and then applying the money and time to make it happen. Like most things in life, however, it’s just not that simple. Achieving the many advantages of an automated welding cell first requires careful assessment of the current welding processes and a detailed plan to automate. Whether it is a fixed automation system or a fully automated robot (see Additional Information: Fixed Versus Fully Automated), automating the welding process offers the potential for numerous benefits: Attaining all of these advantages depends on how well suited the process is to automation in the first place. The variables determining suitability for automation include the part(s) to be welded, part volume, the facility, incoming power and personnel. Automated welding systems are built for speed and thrive on repeatability. Parts that present gap, fit-up and access challenges will quickly hobble an automated welding process, as will a part that requires intricate clamping and tooling to hold it in place. As a rule, the human welding operator will always perform better than a robot or fixed automation for parts where weld positions are obstructed or where a part requires precarious placement. Instead, to automate successfully the parts manufactured upstream from the automated welding cell should be as simple and consistent as possible so the robot can execute the weld at the same place over and over again (if the joint moves, the robot will not be able to weld it). A good way to determine if a part is suitable for automated welding is to supply the robot OEM or welding solution provider with a blueprint of the part that can indicate how repeatable it is. An electronic CAD drawing of the part, which the robot OEM can import into its simulation software, is even better. This drawing helps to visualize the quality of the planned weld and how the part and its tooling can be fine-tuned to optimize the automated welding process. Another upstream consideration companies should make prior to automating is to assess their parts flow. If the facility wants to implement automation to relieve a bottleneck at the welding cell, then it should be certain there are no delays in upstream part fabrication or rework required before sending parts to the welding cell. The manufacturer also needs to make sure that the human worker supplying the robotic cell can match the cycle time of the automated cell. If these solutions aren’t possible, companies may want to consider that some robot manufacturers offer automation solutions for upstream applications as well. These machines are equipped with sophisticated part recognition systems that can pick up parts, manipulate them to the correct orientation and deliver them to the automated welding cell. If fabricators doubt the consistency and cycle time of their manual upstream processes, they might consider this more expensive option. In order to justify an automation investment, companies need to be sure the volume of parts it needs to produce is high enough, as a robot’s key benefit is the ability to produce high volumes of quality welds. Realistically, however, many small fabricators may not have an application with a high part volume. Still, these facilities may be able to select two or three smaller volume applications and program a robot to weld those different parts instead. Part volume is such a critical factor in estimating the return-on-investment, as up to 75 percent of the cost of a semi-automatically welded component is the labor. Accordingly, even if the facility will be producing the same number of parts, it may be able to justify the investment due to the amount of labor an automated welding process eliminates. Facilities need to factor in how much space they can devote to fixed automation and robotics, as the physical footprint of these solutions and the room needed for the flow Additional power sources and ventilation will probably be needed when integrating automated cells. The optimum power supply for a fabricator that uses automation is 480 volt three-phase. The facility also needs to consider bulk delivery for both wire and gas. Instead of buying 40 lb. spools, for instance, the facility would need to purchase 600 or 900 lb. drums. In terms of gas delivery, the priority is to limit robot downtime, which can be achieved by investing in manifold systems that will eliminate the downtime associated with frequent bottle change-outs. Many manufacturers opt to work with a third-party integrator after they’ve decided to implement automation. System integrators are knowledgeable about all aspects of facility modifications necessary for automation, including important safety regulations that apply in the fabricator’s region, country or state, in addition to those specified by OSHA and RIA (Robotic Industries Association). Automation doesn’t necessarily imply complete independence from human insight and supervision. A skilled welder who knows the process should be available to program the robot or fixed automation system and to troubleshoot the automated welding process as needed. If such a person is unavailable or a new hire is unworkable, facilities should be prepared to vet robot OEMs to determine the availability and costs associated with OEM-based training of their personnel. Some automation companies may offer deals that include training for high volume purchases, and companies can expect this training to last one to three weeks depending on the certification level desired. Automating welding processes can dramatically increase production while at the same time decreasing labor costs and improving weld quality. Transitioning to automation, however, shouldn’t be done impulsively – automation is not suited to every facility or process. Manufacturers need to develop a plan that accounts for a variety of factors, including the part to be automated, the facility, part volume and personnel. Failure to complete an upfront evaluation of the current semi-automatic welding process could result in an imperfect automation solution that requires constant “baby-sitting.” With meticulous evaluation of these aspects, however, facilities can transition to an automated process that requires only nominal supervision and generates a solid return on investment. In fixed automation, the torch rotates around a fixed part or vice versa—the part rotates around a fixed torch. Examples are lathe-type application in which a simple part is spun, welded and ejected from the process, or a straight-line weld, in which the torch advances, makes a six-inch weld and retracts to the neutral position in preparation for the next weld. Fixed automation is extremely efficient and cost-effective. Robotic automation executes complex programmed motions in space to perform welds. Guns mounted on arms with articulated joints enable them to reach, rotate and pivot to gain access to the part. Facilities choose robotic automation when they anticipate frequent job changes or more complex parts, which alter the welding task. Robots offer the flexibility to be re-programmed and re-tasked as the facility’s needs dictate, making them the preferred automation choice for most manufacturers.
Robotic MIG welding can provide companies with very significant gains in productivity and excellent return on investment — when done right. Unfortunately, companies often make the mistake of focusing too much on big picture items like the power source and robotic arm, neglecting the small but equally important details like the welding wire, MIG gun and consumables. While the power source and robot arm certainly are important components to consider, even the most carefully chosen and configured robot system can fail to reach its potential without the right components to support the system. That said, below are several tips for maximizing your robotic welding productivity and reducing robot downtime through proper wire, gun and consumables selection. Because robotic welding involves very precise tolerances and even minute variations in the wire feed process can result in unacceptable welds, it is important to choose a wire designed to feed smoothly through the drive rolls and liner. Wires engineered specifically with robotic applications in mind often provide better feeding characteristics than those designed for all-purpose use. Another consideration peculiar to robotic applications is the arc starting performance of the wire. A wire that produces unreliable and inconsistent arc starts can negate the productivity benefits of a robotic system by creating substantial down time, or downstream rework. For many robotic MIG applications, a metal-cored wire will provide excellent weld quality, metal deposition, mechanical properties, bead appearance and travel speed. Because it contains deoxidizers and other arc stabilizers in the core of the wire, metal-cored wire also produces very little to no spatter, which reduces post-weld cleanup and the frequency with which the welding gun must be cleaned. This is particulary evident when welding over mill scale. Another benefit unique to metal-cored wire is that it reduces sub-surface porosity caused by extended wire stick-out and changes in gun angles, which often goes undetected during visual weld inspection. Further, the wide, round penetration profile of metal-cored wire allows a greater margin of error in wire placement, particularly in fillet welds where fusion at the root is critical. Metal-cored wire won’t be the right solution for every robotic application, however, so be sure to check with a robotic welding expert or wire manufacturer prior to making a purchase decision. Responsible for delivering the electrical current to the welding wire and shielding gas to the weld pool, the MIG gun consumables play a crucial role in ensuring weld quality. The challenge lies in delivering consistent current under extreme heat for hours and days without interruption. Because robotic welding involves a lot of arc-on time, it is important to choose consumables that are durable. Tregaskiss® AccuLock™ R consumables have tapered connections to ensure reliable conductivity and reduce heat buildup that could lead to premature failure. AccuLock contact tips also have greater mass at the front end and are designed so 60% of the tip is buried in the gas diffuser. Both features help protect the contact tip from the heat of the arc and make it last longer, reducing downtime for changeover. The contact tips feature coarse threads and a long tail that concentrically aligns the contact tip in the gas diffuser before the threads engage. This design virtually eliminates cross-threading, so there is less downtime for troubleshooting associated with this issue. For pulsed welding applications, which can be especially harsh on contact tips, AccuLock HDP contact tips are a good choice. The hardened insert helps the contact tip last 10 times longer than those made of copper or chrome zirconium. As part of a common consumable platform™, AccuLock R consumables share a common contact tip that can be used with Bernard® AccuLock S consumables for semi-automatic MIG guns. Because most shops that use robots also have semi-automatic applications, using an interchangeable consumables system can reduce inventory footprint and downtime associated with retrieving the incorrect consumables when replacement is needed. Front-loading liners allow robotic MIG welding operators to replace the liner from the front of the gun instead of the back end, where the welding cable connects to the wire feeder. These liners can be changed in much less time than standard liners, providing the opportunity to change a liner on a proactive basis during short periods of downtime, rather than waiting for the next available time allotted for Preventative Maintenance (PM). A front-load liner typically requires the operator to install a retainer at the back end of the gun during initial installation. Following this initial installation, the operator simply removes the front-end consumables, pulls the old liner out, slides the new liner on over the wire and replaces the consumables. The benefits of robotic MIG welding rely on volume and uptime, so it should be no surprise that reducing robot downtime for routine wire changeovers can be one of the most effective ways of maximizing return on investment and productivity. The ideal filler metal package for a robotic application should be large enough to reduce wire changeovers as much as possible, yet not so large that the same wire sits on the shop floor for more than a few days. Filler metal is usually shipped in air-tight containers, and once opened, it runs the risk of absorbing moisture, dust, oil or other contaminants that can affect its welding performance. Also consider where the filler metal will be located within the welding cell. In some cases, weld cell configurations make large filler metal drums impractical, but when possible, stocking at least one extra filler metal package near the robot can help reduce downtime. Finally, selecting recyclable filler metal packaging can reduce cost and the amount of employee time spent properly separating and disposing of recyclable and non-recyclable packaging materials. Durability is a desirable quality in both semi-automatic and robotic MIG guns, but in the case of robotic applications it becomes absolutely paramount. Inevitably, the welding gun will occasionally experience a physical crash with other equipment (such as clamps, fixtures, etc.) or the weldment itself. While it’s difficult to completely avoid occasional collisions, selecting a robust robotic MIG gun will greatly reduce the downtime, lost production and product replacement costs associated with these unforeseen collisions. Typically, the neck of the robotic MIG gun takes the brunt of the impact so choosing a product with sufficient armor should help maintain the TCP (tool center point) and can minimize costly interruptions to productivity. In addition, selecting a robotic MIG gun with a large work envelope will help improve joint accessibility and reduce the complexity of robotic programming and the possibility of unexpected collisions. Turning production over to a robotic welding system is never a task to be undertaken lightly. Done hastily and without carefully selecting the right equipment, including the wire, MIG gun and consumables, the endeavor could result in excessive downtime and greater expenses. Properly considered and done right, however, robotic welding can yield impressive gains in productivity, reduced downtime and rework and increased bottom line profitability.
Automated welding systems have the potential to increase productivity, improve weld quality, reduce labor and materials costs, mitigate the welder shortage and most importantly increase a company’s overall profitability. These systems can be expensive, but they have come down in price substantially over the past 10 years, and those costs need to be understood within the context of the benefits the system provides. In a globally competitive environment, rather than asking yourself whether you can afford to automate, you might consider asking whether you can afford not to automate. Automation won’t be right for every company, however, and choosing the right system for your operations is crucial to ensuring a wise investment. Like most purchasing decisions, success in automation depends almost entirely on planning and preparation. The rewards can be significant, but so too can the costs in making the wrong decision. Below are eight factors that you need to consider when deciding whether and how to automate your welding operations. A single automated welding system can perform the welding of up to three employees, oftentimes with better quality results, and eliminate bottlenecks that occur at the welding stage of the manufacturing process. But that’s not all. An automated system can lower your consumables cost by using only as much filler metal as is necessary. It can also greatly reduce your scrap and rework rates by improving the visual and mechanical quality of your welds, and reducing or eliminating spatter. Further, automating your welding can reduce your labor costs, allowing you to reallocate those resources elsewhere in your plant. If you are in an industry where your competition is still welding by hand, investing in an automated system could provide you with a competitive advantage in your customers’ minds. The benefits of automating can be significant, but those benefits come at a price. Many companies, especially smaller fabricators and those with frequently changing production lines, need to see a payback period of no more than 12-15 months in order to justify the investment. On the other hand, companies that know their production needs will not change for years can often justify a longer payback period. Calculating payback first involves determining your current product cycle times and comparing that to the potential cycle times of an automated system. If you need to produce X number of parts per week, for example, and an automated system can produce those parts in 1/4 the time it takes a human operator, you’ve just increased your productivity by 75 percent. Given that approximately 70 percent of a welding operation’s costs are for labor, the chart below shows the labor saving potential of an automated welding system. Overwelding is a common and costly occurrence in semi-automatic welding. A weld bead that is 1/8-in. larger than necessary can double your filler metal costs. An automated system can reduce your filler metal costs by only putting down as much material as necessary. Automated systems also use bulk filler metal drums, which can further reduce your filler metal costs by requiring fewer changeovers and yielding bulk purchasing discounts. Using bulk tanks for your shielding gas, another highly recommended step in optimizing your automation capabilities, will further increase your return on investment. Automating a welding cell won’t be the right course of action for everyone, but the capabilities of automated systems and their increasing affordability is making it a wise choice for many companies. You must be able to provide the robot with a consistent supply of material and ensure that the parts being welded do not pile up in another part of the plant. If your robot only serves to move the production bottleneck from the welding cell to the painting booth, for example, then you have not increased your productivity. Repeatability and measurability is a precursor to automation. If you don’t have a blueprint (preferably an electronic blueprint), you likely won’t be able to automate the welding for that part. You should also have a thorough understanding of your existing productivity from which to measure the improvements of the automated system. Further, parts should have large batch runs (although there are some exceptions to this rule), tolerances within thousandths of an inch, and configurations that allow access from an automated gun. Make sure you have the right workforce to automate your operations. An automated welding system requires a trained operator to make sure it is running properly. Because it takes longer to become a skilled welder than it does to learn how to operate an automated welding system, it usually makes sense to train a welder to operate the automated system rather than trying to train a tech-savvy employee in proper weld quality identification and troubleshooting. Automated systems generally require three-phase 480v electrical power, and only reach their full potential with the use of a bulk gas/manifold system, so these factors should also be considered in determining whether or not to make the leap into automation. There are two basic types of automated welding systems, robotic and fixed. A robotic system is what most people think of when they think of automated welding. It uses a robotic arm that can move along several axes and a positioner that moves the part to be welded. Robotic systems are more expensive and more complicated than fixed automation systems, but you can reprogram them to accommodate different product lines if your business changes. This makes robots especially attractive if you have a small, growing fabrication shop. In a fixed automation system, either the gun or the part is fixed in place, making the system less flexible in accommodating changes in product configuration and design. A product that requires only straight or curved welds along a single plane is usually a good candidate for a fixed automation system. Planning a successful automation effort involves carefully choosing the equipment that will make up the system, including: the positioner, the tooling, the welding power source, the robot, the gun, the welding wire and the peripherals. The positioner is responsible for, as its name implies, turning, rotating or otherwise moving the part into an optimal position to be welded. In many cases, this involves moving the part so that the system can weld in a flat position for optimal deposition efficiency. The tooling holds the material in place to be welded and is one of the most critical components of an automated welding system. Because the gun moves along the exact same path each cycle, if the weld joint is out of place by as little as a few thousandths of an inch, the resulting part could end up in the rework or scrap bins. Simply designing the tooling correctly at the beginning isn’t enough, however. The tooling is subject to mechanical wear, heat distortion and other factors that could cause weld defects, so a trained operator must ensure the tooling continually maintains acceptable tolerances. Power sources, especially those designed specifically for automated welding, can monitor and respond to the arc conditions within milliseconds, making it possible to reduce heat input to the materials, increase travel speeds, reduce spatter, bridge gaps and work with a wide variety of metals. Choose a power source that offers these benefits. Selecting the right gun and welding wire can also have a significant bearing on the productivity and profitability of your operation, and should be chosen based on how they perform in conjunction with the rest of the system’s components and parts. Subjected to intense heat, spatter and other elements, the gun must be highly durable in order to avoid maintenance downtime. The gun should also be easily serviceable in order to minimize any downtime for spatter removal, contact tip changeover and other routine maintenance. Finally, robotic peripherals, such as nozzle reamers, anti-spatter applicators and wire cutters should also be factored into your automation effort. These devices can improve uptime and welding performance. Predicting your company’s automated welding needs in the years ahead will help determine the type of system you need. If you have a part that easily lends itself to a fixed automation system, for example, but you aren’t confident that you will be making that part three years from now, a robotic system might be the better choice. It can be reprogrammed and retooled to accommodate your needs in the future. Your automation partner, whether it’s your welding supplies distributor, a robotic systems integrator, an equipment manufacturer or an independent consultant, should be available with support and service throughout the transition to an automated welding system, not just until you install the robot. Further, most reputable robot manufacturers provide at least a week-long training course, as well as 24-hour support hotlines and field service technicians who can make on-site repairs and/or consultations. The popularity of automated welding operations is growing by leaps and bounds thanks to their welding capabilities and return on investment. If you have a repeatable part, efficient material flow and a desire to increase your company’s productivity, you should at least be looking into automation. You should also assume that your competition is as well. The first step toward determining if automation that is right for you will be to contact a trusted expert who can conduct an on-site analysis of your specific circumstances, recommend the appropriate equipment and configurations, and calculate the payback you can expect.
Given that the single-most enticing reason for companies to invest in welding automation is to improve productivity, it may seem counterintuitive to stop or slow production — for any reason. But what if minor downtime could save your company vast amounts of time, trouble and money in the long term? Or give you a greater competitive edge by improving your overall efficiency? Simply put, that is the basis of a preventative maintenance or PM program. Unfortunately, far too often companies fall victim to the ‘if it isn’t broken, don’t fix it’ mentality when it comes to caring for automated equipment, including the robotic MIG gun and consumables. Doing so, however, can have dire consequences. Not only is there a risk of losing productivity and lowering throughput if the entire system isn’t functioning properly, but even the slightest malfunction can result in higher labor, lower weld quality, greater rework and wasted materials. But most importantly, downtime associated with troubleshooting and completing repairs can significantly lower the return on investment sought by transitioning to welding automation in the first place. And while caring properly for the whole of an automated welding system is imperative, maintaining the robotic MIG gun itself is just as important. In fact, the robotic MIG gun (including the consumables) is often one of the most overlooked components of the system — and also one of the easiest to maintain. Fortunately with some simple steps, you can make robotic MIG gun maintenance an important part of your overall preventive maintenance program and ensure the most consistent performance of your entire automated welding system along the way. Preventative maintenance programs, particularly those for robotic MIG guns, are not just beneficial for large companies with multiple automated welding cells. All companies, regardless of their size or arc count should regularly care for this equipment. Like the key tenets of the 5S methodology (Sort, Straighten, Shine, Standardize and Sustain), taking proactive steps to ensure the productivity of your automated welding operation, starting with the guns (no matter how many you have) can positively affect your company’s workflow, throughput and bottom line. The scope of a preventative maintenance program varies according to each particular application. Specifically, the higher the risk of problems in your process — logistically and fiscally — the more frequently you should take steps to prevent them. Take for example a heavy equipment manufacturer that welds thick plate and has an average welding cycle time of 4 hours per part. This company stands to have greater downtime and more expensive rework to remedy a problem than a company that welds smaller, less expensive parts in a four-minute weld cycle. Therefore, this higher risk process needs more frequent care of its equipment, including its robotic MIG gun, as part of an overall preventative maintenance program. Welding engineers, welding supervisors, tool and die employees or members of the maintenance staff are all viable candidates to oversee a preventative maintenance program. There is, however, one single key to these employees executing a program successfully: training. All personnel involved need to be trained to be aware of the potential problems that could arise in the weld cell and how to prevent them. To make your robotic MIG gun a central part of a preventative maintenance program takes significantly less time than you might imagine. In fact, most of the maintenance can be completed shift-by-shift with minimal off-line time. Note, however, that such ‘in-process’ preventative maintenance does not constitute the entirety of a PM program. There may be procedures that need to take place off-shift due to their complexity and the time necessary to complete them. The first thing to know about maintaining your robotic MIG gun is to always use the proper tools for the job. When changing diffusers (or retaining heads), use a proper adjustable or crescent wrench. Contact tips should also be installed with a proper pair of pliers or welpers, or a specific tip installation tool. Always use a sharp pair of side cutters when trimming your robotic MIG gun liner, as any other type of tool will likely create a large burr that can wear or drag on the welding wire. Secondly, during your in-process robotic MIG gun maintenance, always check that the connections on the gun, consumables and cable are secure, in good working order, and that these components are all as clean as possible. This task can be completed relatively quickly when the welding operator overseeing the weld cell changes out a finished part and/or during a routine contact tip changeover. Specifically, check that the diffuser is tightly connected to the neck (or neck) and that, in turn, the contact tip fits snugly in the diffuser. Similarly, be certain the nozzle and any seals around it (depending on the style you use) are secure. Having tight connections from the neck through the contact tip ensures that you have a solid electrical flow throughout the components and that there is minimal heat build-up that could cause a premature failure. Minimizing heat build-up also lessens the chances of troublesome occurrences like burn-back, which could result in unplanned downtime to change over the contact tip and diffuser, as well as poor arc stability, which could cause quality issues and rework. Note, any change in the color of the consumables (particularly if the copper changes to a dark orange or purple) is a good indication that they are loose and require tightening. Additionally, check that the power pin and welding cable lead are properly secured and that the cable is not rubbing against any part of the robot’s metal casting, as this can eventually cause it to loosen or wear out the cable. A worn spot on your robot (e.g. the absence of paint) or on your tooling is a good indication that the cable is rubbing against it. Remedying such a problem needs to occur while the robot is off-line, since it could require repositioning the tooling or adding some form of cable management device; however, a quick in-process inspection that identifies the issue can flag it for a later, proactive solution. Visually inspecting your contact tip, nozzle and diffuser for spatter build-up is also a crucial part of a preventative robotic MIG gun maintenance program. Check, too, that your grounding blocks are clean and free of spatter in order to make good contact. Like loose connections between components, spatter build-up can cause excessive heat to be generated from the contact tip to the MIG gun neck, fouling the internal and external threads—even to the point of causing the torch itself to overheat and fail. Spatter can also block shielding gas flow, causing problems like porosity or other defects that require costly rework. It can also add to your overall costs for the consumables themselves, as spatter build-up will require you to changeover nozzles and contact tips more frequently than necessary. To prevent such problems, inspect your consumables regularly for spatter accumulation. Even better, consider using an automated consumables cleaning device, often called a nozzle cleaning station, reamer, or spatter cleaner to minimize spatter build-up. As with any part of your automated welding system, adding equipment like a spatter cleaner also adds costs to the initial capital investment; however, as with any part of a preventative maintenance program, it can save you money over the long term. Like its name implies, a spatter cleaner device removes spatter (and other debris) that builds up in the nozzle and diffuser as part of the normal welding process. Using this product in conjunction with a sprayer that applies an anti-spatter compound provides further protection against spatter accumulation and reduces downtime needed for fixing weld defects. Next in the preventative maintenance of your robotic MIG gun, determine how long it takes for the gun liner to become worn or fouled using your particular process, and As a side note, remember to cut the liner to the correct length, per the manufacturer’s recommendation. A liner that is either too long or too short can lead to poor wire feeding and poor weld quality. Improper liner lengths can also lead to premature contact tip failure. Periodically, check the force required to pull the welding wire from the feeder through the robotic MIG gun to ensure that there isn’t too much drag, which indicates that there is a build up of debris the liner. To complete this task properly, the drive rolls of the feeder should be released first. Also, it is best to perform this task in between shifts, as opposed to during contact tip changeover, as it will take a bit more time. During this time, you should also check the force needed to pull the welding wire from the coil through the wire conduit to the feeder. While the conduit and feeder are obviously not part of your robotic MIG gun, caring for them directly affects the performance of the gun itself. For example, debris in the wire conduit, if undetected through regular inspections, can be pulled through the length of the robotic gun, causing liner and consumable problems — especially wire stoppages that lead to burn-back. Similarly, too many twists or bends in the welding wire that feeds through the gun, can also affect the longevity of your gun liner, as well as arc stability and weld quality. It is a good preventative measure to check that the wire conduit is clean, that drive roll pressure is properly set and that you inspect and replace worn drive rolls and wire guides. Maintaining your robotic MIG gun is just part and parcel of an overall PM program, but it is significant nonetheless. Most of the robotic MIG gun maintenance, as discussed here, can be completed on a shift-by-shift basis with minimal interference with your cycle times and with minimal labor — especially when you consider the time and cost of resolving problems instead of preventing them in the first place. Remember, preventative maintenance programs don’t have to be complicated, only effective. So take some time to consider the preventative maintenance needs specific to your automated welding operation in order to establish the scope and frequency of your own program.
From high-volume, low-variety manufacturing facilities to low-volume, high-variety fabrication shops, robotic welding has become increasingly popular due to the potential weld quality and productivity improvements it can provide. Not only do those benefits make it an attractive investment for growth and profitability, but they can also provide companies with a competitive edge. Selecting the right equipment for a robotic welding operation, however, is not a task to be taken lightly. From determining the correct style of robot to suit an application’sparticular requirements to deciding which welding peripherals to purchase, companies must always choose wisely. Selecting the appropriate robotic MIG gun that suits the requirements of the application is also essential for optimizing the return on investment. For example, using a robotic MIG gun that has a higher amperage capacity than required can unnecessarily increase the total cost of ownership. Conversely, selecting an inadequate MIG gun can lead to performance issues, costly downtime and premature failures. Instead, companies are encouraged to select a robotic MIG gun that is suitable for the amperage, duty cycle and cooling capacity needed for the application. Doing so helps ensure good weld quality, and reduces equipment and maintenance costs. The right robotic MIG gun also helps companies improve productivity. The following information helps to outline key considerations towards making the right selection. Typically, air-cooled robotic MIG guns (rated at 500 amps) operate comfortably in the range of 200 to 300 amps at approximately 60 percent duty cycle with mixed gases (i.e. welding continuously for 6 of 10 available minutes). Further, these guns are ideal for welding thinner materials — typically upwards of 4 mm thick — and work best for shorter welds on high volume applications, including (but not limited to) those in the automotive or recreation equipment industry. Air-cooled robotic MIG guns, like their semi-automatic counterparts, rely on the ambient air to cool them during the welding process. These guns feature a unicable through which the welding wire, gas and power are all delivered. Air-cooled unicables use the appropriate amount of copper to create a conductor that is capable of managing welding current without any additional cooling. When compared to water-cooled unicables of similar rating, air-cooled unicables generally have up to four times the circular-mils (i.e. cross section) of copper. There are several advantages to using air-cooled robotic MIG guns, the most significant of which is their durability. An air-cooled neck has a much stronger and durable construction when compared to the neck on a water-cooled robotic MIG gun, making it more resistant to bending in the event of a collision or through general wear. Replacement parts for air-cooled robotic MIG guns also cost less and are easier to maintain. These guns tend to have a more streamlined design and smaller working envelope, allowing greater access into smaller joint configurations than a water-cooled robotic MIG gun. Too, air-cooled robotic MIG guns maintain their accuracy very well, which makes them an excellent option for applications requiring consistent, repeatable welds. One limitation to air-cooled robotic MIG guns is the lower duty cycle when compared to water-cooled guns; they are not capable of welding continuously for as long as a water-cooled robotic MIG gun. Water-cooled robotic MIG guns offer excellent advantages for applications that require welding at higher amperages for prolonged periods of time. These guns provide high amperage capacity — generally 300 to 600-plus amps — and are capable of managing a duty cycle within the 60 to 100 percent range. They are designed for welding on thicker materials (typically 1/4 inch and greater), making them a good choice for applications in heavy equipment manufacturing or similar such industries. As a rule the larger the overall size of the weldment, the greater the chances the application will require a water-cooled MIG gun. To prevent overheating, water-cooled robotic MIG guns rely on a supply of water or coolant from an external source. These sources include circulators or chillers, which tend to add to the overall cost and maintenance requirements of the system. The coolant travels through a water hose in the gun’s cable bundle (also containing the power cable, wire, and gas and water return hoses) and circulates up through the neck to the consumables. For very high-amperage applications, there are also water-cooled nozzles that are capable of circulating the coolant around the nozzle, but these are more expensive than standard ones. As mentioned previously, water-cooled power cables (found in the cable bundle) have approximately 1/4 of the copper found in an air-cooled unicable; thus, water-cooled unicables quickly fail if the water supply is interrupted. This factor is a disadvantage of water-cooled robotic MIG guns, as the parts can be expensive and time consuming to replace should they become damaged. Routine maintenance of the cables within the cable bundle can also be difficult, since they are all in close proximity to one another. And because these guns have internal water chambers in the neck, that part is inherently weaker than the neck on an air-cooled robotic MIG gun and much more likely to bend in the event of a collision. Still, for high-amperage applications that require high capacity cooling to protect the gun during long periods of welding, dealing with these disadvantages still make having a water-cooled robotic MIG gun worthwhile. For companies that weld multiple thicknesses of base materials and require both high and low amperage capabilities from a robotic MIG gun, a hybrid air-cooled/water-cooled robotic MIG gun is a good option. These MIG guns have a durable neck like an air-cooled model, but offer the higher cooling capacity of a water-cooled MIG gun. They feature exterior water lines that run along the outside of the neck to the nozzle, as opposed to through the neck like water-cooled MIG guns have. Hybrid air-cooled/water-cooled robotic MIG guns typically offer 300 to 550 amperage welding capacity at 60 percent duty cycle (using mixed gases). Hybrid air-cooled/water-cooled robotic MIG guns also have features that provide easier maintenance compared to a true water-cooled product. For example, the water lines run independently of the power cable and are more accessible than with a standard water-cooled MIG gun, so these guns do not need to be taken off of the robot for maintenance. Plus, if there are issues with water circulation, these guns can rely on the underlying air-cooled unicable to provide enough current-carrying capacity to avoid a catastrophic failure such as destroying a power cable or other components. Overall, the features of the hybrid air-cooled / water-cooled MIG gun help provide a lower total cost of ownership for the gun. One limitation of these MIG guns, like a standard air-cooled model, is the limit to duty cycle. For applications that require continuous duty cycles, these MIG guns would not be the best choice and a water-cooled product may have to be deployed. Regardless of which robotic MIG gun is right for a given application, good preventive maintenance is critical to ensuring product longevity and reducing unscheduled downtime. In particular, most robotic MIG gun manufacturers recommend using a nozzle cleaning station to prevent spatter build-up that can lead to quality issues or downtime (and costs) related to consumable changeover. Checking for loose connections along the length of the robotic MIG gun — from the power pin to the nozzle — is also key to preventing quality issues or damage that could cause the gun to fail prematurely. Remember, choosing the appropriate robotic MIG gun to suit the requirements of the application is essential for optimizing the return on investment. Using the right robotic MIG gun also provides for a more reliable system and can help manage the total cost of ownership, particularly by minimizing performance issues, costly repairs, unscheduled downtime and premature failures. In the end, it takes less time and money to protect a robotic MIG gun with preventive maintenance procedures than it does to take the gun offline for repair or to replace it.
Welding gun nozzles play a critical role in the welding operation. Having the right nozzle for the job can help reduce weld defects, rework and associated downtime — while also extending consumable life. All of these factors impact the bottom line. Unfortunately, like other MIG welding consumables, the importance of selecting the right nozzle is often overlooked. In any welding application, the right shape and style of nozzle, however, can have a significant impact on the quality, productivity and overall cost of the welding operation. Knowing how to store and handle nozzles properly can also help improve their overall performance. Consider these tips to get the best results. There are several shapes of nozzles available, including straight, bottleneck and short or long taper nozzles. Straight nozzles typically have larger inside diameters (e.g., 3/4 inch), but don’t offer as good of joint access. If greater joint access is critical, a bottleneck nozzle may be the better option. These nozzles are particularly good for automated welding applications. A common inside diameter for a bottleneck nozzle is 1/2 inch. Short and long taper nozzles are also common choices for gaining good joint access. Note, that long taper nozzles typically have a smaller inside diameters and may collect spatter more readily. When possible, using a short taper nozzle can help prevent such a problem. When selecting a nozzle, it is important to find one that provides the best joint access for the application. It is also imperative that the nozzle allows for the proper gas flow to the weld puddle in order to keep contaminants away. The best choice is to use as large of a nozzle as possible that still allows access to the weld joint. Doing so helps ensure the greatest shielding gas flow. Larger nozzles are also less prone to collecting spatter compared to those with smaller inside diameters.? 1For extreme heat applications, consider water cooled nozzles/guns. Nozzles are typically available in heavy-duty or standard styles, and in slip-on or thread-on varieties. Heavy-duty nozzles have thicker walls, as well as thicker insulators, and are designed for use in applications ranging from 400 to 600 amps. Due to their heavier construction, these nozzles resist heat better than standard varieties. Standard nozzles tend to have a thinner wall and are better for 100- to 300-amp applications. Slip-on nozzles, as their name implies, simply slip on to the front end of the MIG gun. These nozzles are quite prevalent in the industry, compared to thread-on nozzles that need to be twisted to install, and they offer the advantage of being able to change over more quickly. A note of caution: when installing slip-on nozzles, be certain that they are fully seated on the retaining head to prevent shielding gas leaks that could lead to poor weld quality. Nozzles are typically available in brass or copper, although chrome-plated nozzles are also available. Brass nozzles tend to resist spatter well and are good for lower-amperage applications (100 to 300 amps), whereas copper nozzles are better for high-amperage applications (above 300 amps) or for those with longer arc-on time. For high-amperage water-cooled applications, there are also nozzles available that circulate coolant around the nozzles, but these tend to be much more expensive. It is important to handle, store and maintain nozzles properly to gain consistent welding performance and prevent premature failure. Selecting high quality nozzles can help these consumables last longer, too. Look for nozzles that are engineered with a smooth surface finish and edges, as these resist spatter build-up compared to nozzles that have an uneven surface or burrs on the edges. Nozzles that have some mass to them are also more desirable than lighter or thinner ones since they tend to resist heat better. Also, consider purchasing nozzles that feature a brass insert. This insert helps the nozzle maintain its inner diameter, and prevents the nozzle from rocking and wearing prematurely. The addition of a high-temperature fiberglass insulator can also help extend nozzle life. Finally, look for heavy-duty crimping on the nozzle — the crimping holds the layers together and is an indication that the nozzle has been built for longevity. When storing nozzles, keep them in their original packaging, usually a small plastic bag. Removing them from that packaging and placing them in a bin can lead to scratches or dents that allow spatter to adhere and will ultimately shorten the life of the nozzle. Use gloves when handling nozzles or replacing nozzles to prevent dirt, oil or other contaminants from adhering to them and inadvertently entering the weld puddle. Periodically inspect the nozzle for spatter build-up and clean it using the tool recommended by the manufacturer as needed and/or consider using an anti-spatter compound to protect against spatter. As with any front-end consumable, nozzles play an important role in maintaining good weld quality and can have a measurable impact on productivity and costs, too. Take the time to select the right ones for each application and maintain them properly. Careful selection and maintenance can minimize downtime and keep your welding operation running more smoothly in the long run. Select From Available Tregaskiss Nozzles
When it comes to welding, many variables can influence productivity and quality. The power source, filler metals, and consumables all factor into the equation and require special attention during the selection process. You must manage these variables properly to ensure their longevity and to help minimize downtime for maintenance and repair. For MIG consumables in particular, several pitfalls exist that can shorten their lifespan. Taking the time to learn tips for keeping them clean and lasting longer can positively affect productivity, quality, and the bottom line. The welding process generates heat that significantly affects the cleanliness and longevity of MIG consumables. Processes like pulsed MIG and other high-amperage applications tend to subject consumables to high heat levels, as do those that generate a lot of reflective heat. As the consumables heat up during welding, the material (usually copper or brass) becomes soft, making the surface area much more prone to spatter accumulation. To avoid this problem, you must determine the best consumables for each application and manage them properly throughout the course of a welding shift. For example, high-amperage applications (above 300 amps) most often benefit from using heavy-duty consumables because they have greater mass and are more capable of dissipating heat. However, if the welding procedure requires you to change the contact tip frequently, a standard-duty contact tip may suffice. Your goal should be to determine which consumables — heavy or standard duty — are most capable of withstanding the duty cycle and heat of the application. A reliable welding integrator often can help you make this determination. When used sparingly, anti-spatter compound can help keep MIG consumables clean in both semiautomatic and robotic welding applications. In a semiautomatic application, dip only the front 1.5 in. of the nozzle into the anti-spatter compound. Submerging the entire nozzle can saturate its fiberglass insulator and potentially plug up the gas holes on the diffuser. This buildup may cause premature nozzle failure or unbalanced gas coverage that can lead to weld porosity. In robotic applications, use the minimum amount of anti-spatter compound required for the application. Too much anti-spatter can build up on the consumables or cause the nozzle to become clogged with debris, leading to poor gas coverage, inconsistent electrical conductivity, or shortened consumable life. Another important way to combat spatter is to inspect the nozzle for buildup on a regular basis and clean it with a soft wire brush or spatter-cleaning tool as needed. Always keep MIG consumables in their original packaging until they are ready for use. Opening them and placing them in a bin can lead to scratches or dents that allow spatter to adhere and will ultimately shorten the products’ life. Similarly, removing contact tips or diffusers from their packaging and storing them in open or dirty containers can cause dirt and oil to accumulate in the threads, which can impede their properly seating together. Keep storage containers for new consumables separate from those for discarded ones to avoid selecting an old contact tip or nozzle that may have dents or scratches and be prone to spatter accumulation. Always wear clean gloves when handling or replacing contact tips, nozzles, and diffusers to prevent dirt, oil, or other contaminants from adhering to them. Installing MIG consumables correctly and inspecting them periodically for good connections minimizes the chance of poor conductivity and the spatter accumulation or premature failure that can result. Always follow the MIG consumable manufacturer’s suggestions for installing contact tips and gas diffusers. Use a pair of channel-lock pliers or other recommended installation tools to install tips and diffusers. Never use wire cutters or side cutters, as too much pressure from these tools can damage the inside diameter of the contact tip. These tools also tend to scratch the surface of the consumables, leaving marks that attract spatter. A good rule of thumb is to hand-tighten the contact tip until it is fully seated into the diffuser, then grip the contact tip with an appropriate tool as close to the base as possible, tightening it one-quarter to one-half turn past finger tight. This procedure helps ensure a good connection, minimizing electrical resistance, overheating, and damage to the consumables, as well as excessive spatter accumulation. Follow the same procedure for installing and tightening the diffuser so that it fully connects with the neck. Some contact tips can be installed and held in place by hand-tightening the nozzle. Check the manufacturer’s recommendation for proper installation instructions. Inspect consumable connections regularly to ensure that they are secure. A liner that is trimmed and installed improperly can cause a host of wire feeding problems that require downtime to rectify. It also affects MIG consumables’ performance, cleanliness, and longevity. Cutting a liner too short causes the liner to misalign with or in the gas diffuser. A misaligned liner will feed the wire off-center, and the contact can fail prematurely as a result. Debris often builds up between the liner and the retaining head when the liner is too short, causing wire feeding issues and poor weld quality. In some cases the gap that is present between the gas diffuser and liner when a liner has been cut too short will cause the welding wire to catch, shaving off a tiny portion of the wire. The small shavings can plug up the contact tip and cause it to fail quickly. A liner that’s too long can kink, which again leads to wire feeding issues that shorten the life of the contact tip. Always be sure to remove any burrs or sharp edges after cutting a liner to ensure smooth and consistent welding wire feeding. Always consult with the liner manufacturer’s recommendation for proper trimming and installation instructions. Also be sure to wear gloves when handling the liner, and avoid dragging it on the ground to keep debris away from the MIG gun. Debris can contaminate the weld and hinder consumable performance. The position of the contact tip (extended or recessed) affects consumable lifespan and cleanliness. The nozzle used in conjunction with a specific contact tip and the wire size also makes a difference. The farther the contact tip extends from the nozzle and the closer it is to the arc, the more prone it is to damage from reflective heat by way of spatter accumulation and burnbacks. A recessed contact tip can help prevent these problems while also providing better shielding gas coverage. For applications that require access into restricted areas, it is important to select a nozzle that provides that access but isn’t tapered so much that it impedes the space around the contact tip. If there isn’t enough space for shielding gas to flow out of the nozzle, the shielding gas could hit the workpiece and begin jetting back or swirling. This action pulls oxygen into the weld pool and increases the risk for spatter. As the bore size on the nozzle decreases, there is less mass to that portion of the consumable, increasing the risk for heat absorption and spatter adherence. As a general rule, select the largest consumable that will work for the application while still providing necessary joint access. Larger consumables are more able to resist heat and spatter buildup, and they often last longer as a result. Selecting consumables with the right material for the application is important too. For example, brass nozzles tend to resist spatter well and are good for lower-amperage applications (100 to 300 amps), whereas copper nozzles are better for high-amperage applications (more than 300 amps) or for those with longer arc-on time. Lastly, always pay attention to the manner in which you manage consumables. Using the same consumables throughout the welding operation can help you to maintain consistent performance and troubleshoot problems more quickly when they occur. The result can be longer-lasting, cleaner consumables that provide more reliable performance and quality.
Companies invest in robotic welding to increase throughput and profitability — so there is a lot at stake when something goes wrong in the process. Unplanned downtime for troubleshooting problems in the weld cell can add up to significant costs. In some cases, companies may hire more employees to address production issues or create workarounds in an effort to mitigate issues that are slowing down or stopping the robotic welding process. Most often, when a problem occurs with a robotic welding system, it’s valuable to ask first: What has recently changed in the process? Has the operator recently reprogrammed the robot? Or was the system restarted after a long shutdown? What about the consumables — has anything changed with them and have they been installed correctly? Quite often, looking at the most recently changed variable in the process can help narrow down the point of trouble. The issue may be something as simple as a loose or cross-threaded contact tip or more complex like an incorrect tool center point (TCP). Whichever the case, it’s important to have good troubleshooting skills to help narrow down the focus and get the robotic welding system back on line sooner. It’s also important to have the right equipment, including welding consumables. The longevity of consumables — nozzles, contact tips, diffusers and liners — in a robotic welding application depends in part on the material being welded, the welding parameters and the consumable style and material. High-amperage, high-deposition-rate applications, for example, tend to be harsher on consumables than those with lower amperages. Pulsed welding operations are also very harsh on consumables, particularly contact tips. Using a contact tip with a hardened insert can help the component last longer — 10 times longer, in fact — by better resisting electrical and mechanical wear. Still there can be multiple causes for poorly performing consumables and/or premature failure. For instance, a cross-threaded contact tip can lead to quality issues due to poor TCP, lack of fusion or poor weld penetration. It can also cause the contact tip to keyhole or wear unevenly. To prevent this, look for a contact tip with a long tail that concentrically aligns the contact tip within the gas diffuser before the threads engage. This design, along with coarse threads on the contact tip, helps prevent cross-threading. Such easy-to-install consumables are ideal for companies who may have less experienced welding operators on staff — and they can minimize downtime for troubleshooting incorrectly installed contact tips. A loose connection between consumables can be the culprit. Loose connections increase electrical resistance, causing the consumables to generate additional heat that can shorten their lifespan and/or cause them to perform poorly. Be certain to tighten consumables properly upon installation, per the manufacturer’s instructions, and check them periodically during routine pauses in welding. For companies that weld thick materials or long welds, it is especially important to make sure that consumables are tightened properly, as the rework for quality issues caused by poorly performing ones can generate much more costly rework than an application that produces multiple smaller parts. Issues with the contact tip are also not uncommon, particularly burnbacks. These are often the result of a liner being trimmed too short. Welding operators should follow the manufacturer’s instructions for trimming and installation, and when possible use a liner gauge to confirm the correct liner length. Contact tips designed with greater mass at the front and those that are buried further within the gas diffuser can help withstand heat better to prevent premature failure. Consumables with tapered connections also provide excellent conductivity so there is less heat buildup that could cause additional wear. When contact tips last longer, there is less need for downtime for changeover and less risk of installation errors. If the robotic welding system utilizes a nozzle cleaning station (also called a reamer) and consumable issues occur, such as spatter build-up, check to see that this equipment is working properly. Also be certain that the reamer is cleaning the consumables at a frequency that is appropriate for the application. It may be necessary to increase the frequency of cleaning and/or anti-spatter spray application throughout the programmed welding cycle. If weld defects — like porosity or lack of fusion — are occurring frequently, it might also be indicative of an issue with the consumables. Check to see that the contact tip and nozzle are free of dirt and debris. Replace them as necessary. Premature power cable failure can occur in both through-arm robotic welding systems, where the cable feeds through the arm of the robot, or in standard robotic welding systems (also referred to as over-the-arm). The power cable may become kinked or worn, causing the failure — or in extreme cases, it may even snap. If any of these situations occur, it is important consider the path the robot is programmed to follow, as well as the length of the power cable being used. First, be certain that the robot’s movements have not been programmed to be too fast or abrupt. Aggressive movements can cause the power cable to snap. Or in some cases, it may cause it to flop around, allowing the power cable to rub against the robot or tooling, or catch on components — both instances that can lead to premature failure. Also, check that the power cable being used is not too short for the application or too long. If it is too short, the power cable will stretch beyond its capacity during routine robotic movements, leading to greater wear. Conversely, if the power cable is too long it may be prone to kinking or becoming pinched by the robot’s arm. Poor wire feeding in a robotic welding application can lead to equally poor weld quality. Issues with the liner, including debris build-up, can often cause the problem. Be certain to change out the liner during routine maintenance to prevent debris build-up from the welding wires and the environment. Blowing compressed air through the liner also helps. Ideally, consider using a robotic MIG gun with an “air blast” feature, which blows the air through the liner during a scheduled time in the robotic program (for example, during a reaming or cleaning cycle). An improperly functioning wire feeder — specifically the drive rolls — can also cause poor wire feeding. Over time, these components can become worn and may not guide the welding wire properly. Or the drive rolls may not be tightened correctly. Inspect the drive rolls for signs of wear and replace them as necessary. Welding operators can also determine whether the drive rolls are the problem through a process of elimination. Namely, by conducting a “two finger” test — disengage the drive rolls, grasp the welding wire and pull it through the gun. It should be able to pull easily through. If it does then it’s possible that the drive rolls are the cause of the poor wire feeding. If the wire does not pull through easily, it indicates a problem outside of the wire feeder and drive rolls, such as debris in the liner or another such restriction within the robotic MIG gun. It may even be the result of having too small of a contact tip in place. Welding operators should also look for kinks in the power cable, as these can also lead to wire feeding problems. Peripherals — in particular, reamers — can help companies optimize their robotic welding performance and extend the life of their consumables. If a welding operator notices that there is an excessive build-up of spatter on the consumables, however, it may indicate a problem with the reamer. There are typically three reasons for a reamer to function poorly. The first relates to the taught position of the robotic MIG gun nozzle in relation to the reamer. That is, where the robot clamps to the reamer. The position should be exactly perpendicular to the cutting blade on the reamer. Any misalignment of the nozzle during cleaning could lead to partial cleaning of the nozzle and excessive spatter build-up. As a first step in troubleshooting, check that the taught position is correct. Secondly, if using anti-spatter solution, check that the spray location is correct. Is the solution fully coating the inside of the nozzle? If not, adjust the location accordingly. The nozzle should be coated until it is slightly damp on the inside and the outside should be covered to within three-quarters of an inch from the bottom of the nozzle. And while it seems like an obvious troubleshooting step: Always be sure to check that there is anti-spatter solution in the sprayer! Lastly, be certain the proper cutting blade is in place and that it is sharp. In addition to speed, one of the greatest advantages of a robotic welding system is the repeatability that it provides, and the subsequent quality of the welds. If a welding operator begins to notice inconsistent welds or welds that are off-location, it may be a problem with the TCP. TCP is the focal point of a tool. In the case of a robotic welding system, it refers to the location of the robotic MIG gun and how it corresponds with the position of the welding wire in the joint (gun-to-work distance). Most often, issues with TCP occur after a collision, during which the neck of the robotic MIG gun becomes bent. To rectify the problem, welding operators should use a neck-checking fixture or neck alignment tool to make sure the neck is bent to the proper angle. It is also important to check that the neck is installed correctly. If the neck isn’t fully seated, it may extend too far and lead to TCP problems. To protect against future issues, it may also be helpful to program a TCP check to verify the proper position. To differentiate between a TCP problem and other problems that could cause off-location welds, first take the neck off the robot, implement a TCP check via the robotic program and verify that everything is on-location. If everything checks out properly, the problem is likely a part or position variation. When something goes wrong in a robotic welding system, it is critical to identify the problem as quickly and accurately as possible. Not only can swift troubleshooting ensure that the operation returns to producing quality, repeatable parts, but it can also help prevent unnecessary costs for replacing components that may not need replacing. Always start with the simplest solutions first and consider keeping a checklist for setup and maintenance procedures. Having a quick reference point can help facilitate the troubleshooting process by identifying potential variables that have changed during the course of routine operations. Robotic welding systems are all about speed and repeatability. When implemented properly, they can help companies gain greater productivity and higher weld quality, while also lowering their costs and, in some cases, providing them with a competitive edge. As with any welding equipment, robotic welding systems have undergone improvements in technology that build on those advantages. For instance, in recent years, the industry has begun to shift from conventional robots with over-the-arm robotic MIG guns to through-arm robots. These robots feature robotic MIG guns whose cable assembly, as the name suggests, runs through the arm of the robot. One significant advantage to this style of robotic MIG gun is its durability. Because the arm of the robot protects the power cable, the cable is less prone to wear from routine torsion, and it is protected from catching on fixturing or rubbing against the robot — all situations that can lead to premature failure. Because they don’t require a mounting arm like conventional robotic MIG guns do, through-arm robotic MIG guns also provide a smaller work envelope. As a result, they are particularly well suited for applications that require access to tight spaces. The automotive industry, for example, often uses through-arm robots. Just like any piece of welding equipment, however, through-arm robotic MIG guns require careful selection and maintenance. They also require a few precautions during the installation process. Choosing a through-arm robotic MIG gun is much the same as choosing a conventional robotic MIG gun, with the exception of the power cable selection. These power cables are typically sold in predetermined lengths according to the make and model of the robot, as opposed to the varying cable lengths available for over-the-arm robots. Having set lengths helps minimize kinking of the cable within the arm of the robot and also helps simplify installation of the MIG gun. Always know your robot make and model when placing an order for a new gun. When choosing a style of through-arm robotic MIG gun, look for one that offers good power cable rotation. For example, some manufacturers place a rotating power connection on the front of the cable that allows it to be rotated 360 degrees. This ability to rotate freely provides stress relief for the cable and power pin, and allows for greater maneuverability for a wider range of applications. It also helps prevent kinking that could lead to poor wire feeding, conductivity issues or premature wear or failure. Also, look for power cables constructed of durable components and materials to help prevent similar wear or failure. It is also important to select the proper amperage of gun and be certain that it has the proper duty cycle for the given application. Most manufacturers offer guns up to 500 amps, in both air- and water-cooled models. Finally, identify whether the robot has collision software or if the robotic MIG gun needs to be paired with a clutch to protect it in the event of a collision. Installing a through-arm robotic MIG gun incorrectly can lead to a host of problems, not the least of which is cable failure. Incorrect installation can also cause weld quality issues, such as porosity due to poor electrical connections; premature consumable failure caused by poor conductivity and/or burnbacks; and potentially, failure of the entire robotic MIG gun. To prevent such problems, it is imperative to consult the manufacturer’s instructions for each specific MIG gun. For through-arm robotic MIG guns, it is also important to note that the power cable needs to be installed in a slightly different manner than a conventional over-the-arm robotic MIG gun. Consider these guidelines. First, position the robot with the wrist and top axis at 180 degrees, parallel to each other. Install the insulating disc and spacer the same as with a conventional over-the-arm robotic MIG gun. Be certain that the power cable position is also correct. The cable should have the proper “lie” with the robot’s top axis at 180 degrees. It’s important to avoid a very taut power cable, as it can cause undue stress on the power pin. It can also cause damage to the cable once the welding current passes through it. For that reason, it’s important to make sure the power cable has approximately 1.5 inches of slack when installing it. (See Figure 1). Secondly, the stud on the front of the power cable needs to be fully inserted into the front connector of the through-arm robotic MIG gun. To achieve this result, always install the stud into the front housing prior to bolting the front end onto the robot wrist. By pulling the cable through the wrist and making the connections in front of the gun, it’s easy to slide the whole assembly back (once the cable is fastened) and bolt it onto the wrist. This extra step will ensure the cable is seated and will allow for maximum continuity and maximum power cable life. Also, be certain to position the wire feeder in close enough proximity that the power cable will not be stretched unnecessarily after installation. Having a wire feeder that is too far away for the length of the power cable can cause undue stress on the cable and front end components. Consistent preventive maintenance is key to the longevity of any robotic MIG gun, including the through-arm style. During routine pauses in production, check for clean, secure connections between the MIG gun neck, the diffuser or retaining heads and the contact tip. Also, check that the nozzle is secure and any seals around it are in good condition. Having tight connections from the neck through the contact tip helps ensure a solid electrical flow throughout the gun and minimizes heat build-up that could cause premature failure, poor arc stability, quality issues and/or rework. Check regularly that the welding cable leads are secured properly and assess the condition of the welding cable on the robotic MIG gun. Look for signs of wear, including small cracks or tears, and replace as necessary. Spatter build-up can cause excessive heat in the consumables and MIG guns, and block shielding gas flow. Visually inspect consumables and the gun on a regular basis for signs of spatter. Clean the gun as needed and replace consumables as necessary. Adding a nozzle cleaning station (also called a reamer or spatter cleaner) to the weld cell can also help. Like its name implies, a nozzle cleaning station removes spatter (and other debris) that builds up in the nozzle and diffuser. Using this equipment in conjunction with a sprayer that applies an anti-spatter compound can further protect against spatter accumulation on the consumables and the through-arm robotic MIG gun.
In addition to implementing lean practices, which many manufacturers find can greatly improve productivity and quality, some may also choose to automate their welding operations as a means to gain a competitive edge or improve profitability. This decision, however, is not one to be taken lightly. While there are many advantages to automating your welding operation, implementing a new automated welding system first requires a careful assessment of the facility, the parts to be welded and your available labor. If you are wondering whether automating is right for you, consider some of the benefits of doing so, along with the many details that you should assess before proceeding. When implemented properly, and for the right application, an automated welding system can provide marked improvements in productivity over a semi-automatic welding process — an automated welding system is significantly more efficient and can provide the throughput of several manual welding stations. That does not mean that skilled welding operators are not required in an automated welding operation. On the contrary, they are a vital part of it. Other advantages of automated welding systems include lower labor costs, as well as excellent reliability and consistency in welding performance. In many cases, an automated welding system can provide companies with an attractive return on investment (ROI) and the opportunity to lower operational costs as well. Automated welding systems rely on accuracy and repeatability to provide the quality and productivity improvements for which they have been designed. To achieve these results, the parts that you have in your welding operation need also to be consistent and repeatable. Gaps, poor fit-up or poor joint access can easily prevent an automated welding system from doing its job correctly. Simple part designs, in particular, are good candidates for an automated welding system, as they allow the robot to execute the same weld repeatedly. If you are considering an automated welding system, you should also be certain that the part does not require intricate clamping or tooling to hold it in place. It is a good idea to have a robotic integrator or welding solutions provider assess your operation and the weldments (or parts) prior to implementing an automated welding system. Generally, automated welding systems are best for high-volume, low-variety applications; however, smaller facilities can still be good candidates for automation. Often, the low-volume, high-variety applications require flexible tooling and more programming to manage several products. The additional complexity may increase the initial investment but the efficiency and productivity improvements of automation can still provide a solid return on the initial investment. It is important to assess your current operation for process flow (or workflow) to determine whether investing in an automated welding system is the right choice. In some cases, your existing operation may have to be reconfigured in advance of automation to prevent bottlenecks that could slow down the movement of parts into the automated welding cell. There are several options available, including the technique of using “U-Shaped Cells” for dedicated products, or setting up a flexible cell that can manage quick tool and fixture changes. These are particularly helpful if your welding requirements change on a daily (or hourly) basis. Automated welding systems can significantly improve quality and reduce the occurrences of weld defects. In many cases, they can also improve weld cosmetics and minimize or eliminate spatter. That being said, you should have a dependable supply of quality components that enter the automated system. Quite simply, if poor quality parts go in to the cell then poor quality parts will come out of the weld cell. Further, a consistent and reliable supply of components is required to maintain a reasonable level of Overall Equipment Effectiveness (OEE) – an important metric that evaluates the effectiveness of the manufacturing operation. Having adequate labor to supply the automated welding system with parts is also imperative. Every moment that a robot sits idle waiting for a part to weld ultimately adds up to lost productivity and increased costs. Automated welding systems require supervision and maintenance. In the process of determining whether this conversion is right for you, you should also assess your available resources and their skill set. Skilled welding operators and/or employees with prior robotic welding experience are the best candidates to supervise the weld cell. If you do not have personnel with those skill sets, be certain that you evaluate the resources (both time and fiscal) you have for training. In many cases, robotic integrators and OEMs offer training that can help provide the necessary troubleshooting and operating skills to manage an automated welding system properly. Once you assess your operation and determine that an automated welding system is a good fit, the next step is find an appropriate robotic integrator (and/or distributor) to make your vision become a reality. In addition to confirming that your parts are suitable and identifying any potential bottlenecks, these individuals can assess your facility to be certain that you have the space and services to support an automated welding system. They can also provide you with advice on updates or tooling changes that need to occur prior to implementation. Likewise, a robotic integrator can help you select the right power source, robot (aka “manipulator”), robotic controller and other key equipment. For example, the ideal power source will be one that helps maximize travel speeds, provides good arc characteristics and minimizes spatter. Additionally, a robotic integrator can discuss the benefits of adding robotic peripherals, such as nozzle cleaning stations, wire cutters and anti-spatter sprayers that focus on extending the life of your welding gun and consumables. Ultimately, the goal when deciding whether to automate your welding operation is to have a thoroughly defined plan before you start. By carefully assessing each aspect of your current welding operation and working with a trusted partner, you should be able to garner all the information you need to make an informed decision and achieve your vision for a more efficient and profitable operation.
When you invest in automation, the goal is to gain productivity and quality improvements that set your welding operation apart from the competition and help increase your bottom line. To achieve success with an automated welding system, however, you need to ensure that the parts you are welding are consistent and repeatable, confirm that your welding operation has good workflow and have properly trained welding operators to oversee the system. You also need the right equipment for the job. In addition to working with a reliable robotic integrator to select and implement the robot, you should also take care to select the right robotic MIG gun and consumables — contact tips, nozzles, liners and retaining heads — for the application. The consumables, in particular, are an easily overlooked part of an automated welding system, but they can have a measurable impact on downtime and day-to-day costs. Consider these suggestions for getting the best performance from these components. The contact-tip-to-nozzle relationship for an automated welding system varies according to the application, but it still has an impact on the welding performance and quality you achieve. Applications that have complex joints or tooling often require an extended contact-tip-to-nozzle relationship. This relationship provides greater access into more complex joints and can help you better accommodate for complex tooling. You should be mindful that this relationship also makes your contact tip more prone to spatter accumulation and may reduce the tip life due to it being more exposed to the heat of the arc. The application of an anti-spatter compound can offer some protection against such situations, but you will also need to monitor your contact tips regularly for signs of wear. Remember, preventive maintenance is better than downtime for resolving problems. Change over your contact tips before issues occur. Using heavy duty copper contact tips is a good option for reliable performance in many welding applications. Contact tips with a hardened insert are ideal for operations employing pulsed welding, as they resist wear from the harsh waveforms, and last 10 times longer than copper or chrome zirconium tips. Checking your contact tips, retaining heads (or diffusers) and nozzles for good connections can also have a measurable impact on your welding performance. Solid connections help ensure reliable electrical conductivity and minimize heat, which in turn provides more consistent weld quality and helps your consumables last longer. Look for contact tips with a long tail and coarse threads, as these help prevent cross-threading and downtime for troubleshooting associated issues like poor penetration. This design aligns the contact tip tail concentrically within the diffuser before the threads engage, making the contact tips easier for less experienced welders to install correctly. These same style contact tips also include greater mass at the front of the tip and bury the tip further in the diffuser than other styles. Such features help the contact tip last longer by resisting wear from the heat of the arc. Longer lasting contact tips mean less downtime for changeover and less risk of installation errors. Also, consumables with tapered mating surfaces provide good electrical conductivity to extend the life of the products. The welding wires you use can impact the performance of your contact tips and it can also affect what size you should use. Larger drums of wires — 500 to 1,000 pounds — are commonly used for automated welding systems to minimize changeover; however, the wire in these drums tends to have less of a cast and/or helix than wire that feeds off of a smaller spool. As a result, the wire often feeds through the contact tip relatively straight, making little or no contact with it. The effect is twofold: one, it minimizes the electrical conductivity necessary to create a good arc and a sound weld; and two, it can cause the welding wire to contact the part being welded and arc back into the contact tip, thereby creating a burnback. This condition automatically creates downtime to change over the contact tip. As a solution, consider undersizing your contact tips particularly if you are using a solid wire. For example, a .040-inch (1 mm) diameter contact tip could work for a .045-inch wire. Check with a trusted robotic integrator or welding distributor if you are using metal-cored wires, as undersizing them is not always feasible due to their tubular construction. You should also consider the impact that the wire you are using has on the longevity of your contact tip. For example, non-copper-coated solid wires tend to wear contact tips (and liners) more quickly than copper-coated ones. The copper on a copper-coated wire acts like a lubricant to improve feedability and can often extend consumable life. It may be worthwhile to factor in the higher up-front cost of these wires compared to the increased cost of purchasing more contact tips for use with a non-copper-coated wire, as well as the downtime for changeover. Automated welding systems require consumables that are capable of withstanding longer periods of welding — and most often higher amperages — than a semi-automatic application. The specific mode of transfer for (GMAW) or (MIG) welding you use can also impact the type of consumables you require. For example, pulsed welding programs in which the power source “pulses” between low background currents and high peaks, are especially harsh on consumables due to the higher levels of heat that the process generates. They tend to cause the contact tip to erode more quickly and therefore require more frequent changeover. You should carefully monitor your contact tip usage if using such a welding program so that you can determine how often the contact tips need to be replaced. Changing over these consumables before they experience problems can help prevent issues like loss of electrical conductivity, burnbacks or excessive spatter accumulation, the latter of which tends to occur when the contact tip becomes too hot and the consumable material softens. Use the time during routine pauses in production for contact tip changeover to avoid interrupting arc-on time. Typically, the tooling on your automated welding system dictates the type of nozzle that you will need to use. Bottleneck, straight or tapered nozzles are common choices since they are narrower than standard nozzles and can provide better access around tooling or into complex joints. Still, always consider the duty cycle and amperage of your application when deciding which nozzle to use. The more tapered a nozzle, typically the thinner it is and the less able it is to withstand higher amperage or higher-duty-cycle applications. If your automated welding system welds at higher amperages (300 amps or greater) and has high levels of arc-on time, it may be a good idea to select a heavy-duty style since these have thicker walls and insulators and are more able to resist heat. Nozzles composed of copper are also a good option, as are those featuring high-temperature fiberglass insulators. Work with your robotic integrator or welding distributor to make the right nozzle selection. Remember that you need to be sure to select one that provides access to the joint, but that is not so narrow (especially in relation to the contact tip) that you compromise shielding gas coverage or unnecessarily shorten the consumables’ life. For all styles and types of nozzles, it is always recommended that you employ a nozzle cleaning station or reamer to help maintain them. A nozzle cleaning station cleans the robotic gun and nozzle of spatter and clears away debris in the retaining head that accumulates during the welding process. These stations can also be outfitted with a sprayer that applies a water- or oil-based anti-spatter compound to protect the nozzle, retaining head, and workpiece from spatter after it has been cleaned. The nozzle cleaning station should be placed close to your robot so it is easily accessible. Also, you should program your robot to use it in between cycles — during part loading or tool transfer — so as not to interrupt your welding operation. It should only take a few seconds for the nozzle cleaning station to complete its job. As a general rule, it is best to select consumables that are well-machined and have smooth, round surfaces, as these are less prone to collecting spatter and tend to last longer. It is also important that you use the heaviest-duty consumables for your application that will still allow you access to tooling. Doing so can help extend their life. Keep in mind that you also need to pay attention to your retaining head selection and the liners that you use in your robotic MIG gun. The retaining head should match your nozzle and contact tip appropriately and offer a secure connection so that you obtain the best conductivity. Also, always trim and install liners according to the manufacturer’s recommendation, using a liner gauge to determine the appropriate length. A liner that is too short or too long can cause wire-feeding problems that require downtime to rectify. As with any part of an automated welding system, the goal is to keep your consumables in working order so that you spend more time reaping the benefits of the process and less time troubleshooting problems.
Most people understand that the electrical circuit is at the heart of the welding operation. What you might not be aware of, however, is how easy it is for disruptions in this circuit to interfere with productivity, weld quality and equipment service life. All of these factors are ultimately affected by conductivity: the ability of the electrical current to flow along the welding circuit. Conductivity can also be referred to through its inverse: resistance, or the interference of electricity to flow freely along the circuit. If the electrical current moves with very little resistance, the material is very conductive. Gold, for example, is one of the most conductive materials on earth (which is why it was used in early telephones and other electrical equipment), but its cost prevents its use in welding equipment. Copper, aluminum and other metals are used in welding equipment because they strike a good balance between cost and conductivity. The copper used in welding equipment does a good job allowing the electrical current to flow. There is still a very small amount of resistance inherent in the properties of the material, but it is not enough to interfere with the welding operation. Excessive resistance along the circuit, however, can cause weld defects, reduce productivity and lead to premature equipment failure. To understand exactly how conductivity impacts almost every aspect of your welding operation, it helps to think about the welding circuit like a garden hose. The water flowing through the hose is analogous to the electrical current in the circuit. If you squeeze the hose in one spot, it reduces the amount of water that is able to flow from the hose. Likewise, an area of electrical resistance, such as a worn out or dirty power pin connection, restricts electrical flow along the entire length of the circuit When resistance prevents the electrons from continuing along the circuit, they convert their energy to heat, which is absorbed by the surrounding components. Heat causes plastic and metal components to expand and to contract when cooled, creating mechanical stress that can lead to premature equipment failure. Interestingly, heat itself is a source of resistance, which is why high heat welding processes, such as with metal-cored wire, demand that the contact tip be recessed as far from the welding arc as practicable. As the contact tip absorbs the heat from the arc, it loses its ability to transfer the current to the wire, resulting in increasingly poor welding performance. Excessive resistance anywhere along the circuit can result in a wide range of problems, including a sputtering or erratic arc, inconsistent weld appearance and frequent contact tip burn-back. These problems occur because resistance in the circuit reduces the amount of current that can flow to the welding arc. When the power source senses the reduced current at the arc, it sends a surge of voltage in order to overcome the restricted current flow. This increased voltage causes the popping and sputtering that leads to poor and inconsistent weld quality. Being able to correctly identify and troubleshoot excessive electrical resistance is critical to reducing the equipment and rework costs. The mechanical connections between the welding components account for most interruptions in conductivity. These include: the connection between the power source and the gun’s power cable plug; the fittings and connections between the gun’s power cable, neck, diffuser, contact tip and welding wire; and the connections between the work lead, welding table and power source. Routinely check these connections before problems arise in order to avoid compounded problems down the road. There are three main types of power cable terminations: compression, set screw and crimped. Compression fittings typically provide the best combination of durability and reparability. Set screw fittings are easily repaired, but often come loose and require frequent tightening. Crimped fittings provide good contact between the cable and gun, but are also susceptible to overheating and gradual degradation. Loose cable, gun and power source connections should be tightened to manufacturer specifications or replaced if damaged. Because the welding wire wears the bore over time, the contact tip should be one of the first areas checked during troubleshooting. A contact tip that doesn’t maintain constant connection to the welding wire should be replaced, regardless of whether it is the primary source of the conductivity problem. Paint and other surface contaminants can reduce the conductivity of the work lead connection. To ensure maximum electrical flow, attach the work lead clamp to clean, unpainted metal and as close to the weld joint as possible. If using rotating work leads, such as turntables and positioners, conductive grease can help increase the conductive surface area between the moving and non-moving parts. The other most frequent source of interruptions in conductivity is frayed copper stranding within the gun or, less frequently, in the work lead cables. These strands can fray and break due to repeated bending and twisting, particularly on guns that don’t contain strain relief components at the connection points with the gun and power source. Also, thermal stresses can cause the copper stranding to become brittle, increasing the likelihood of fatigue failure. For this reason, the gun cable should only be bent or twisted if absolutely necessary. The resistive heat caused by frayed cable stranding, in addition to causing poor weld performance, can also accelerate the degradation of the remaining intact strands and cause the eventual failure of the cable. Unfortunately, it is difficult and often impractical to inspect the cable for damage as a preventative measure. Check the mechanical connections and fittings first if poor conductivity is the suspected source of a welding problem, and then proceed to check the condition of the cable. It may be possible to cut and re-terminate the cable if the damage occurs near the connections to the power source or gun. Severe cable damage or damage near the middle of the cable may require replacement of the cable or the entire gun. Welding technology has advanced substantially since the days of DC ‘buzz boxes,’ but one thing that has remained constant throughout the decades is the need to establish and maintain a robust electrical circuit. Resistance from loose fittings and connections will occur as a natural part of the wear and tear that welding equipment undergoes during normal use. However, knowing the common signs of poor conductivity and following a regular inspection routine will help ensure that built-up resistance doesn’t cause undue equipment and rework costs.
Like any welding process, MIG welding has its complications. Even so, there is no reason to let common problems slow you down. With a bit of knowledge and some solid troubleshooting skills, you can easily find the right solution to get back to welding—sooner than later. Consider the following guidelines to help you along the way. Porosity occurs when a gas pocket becomes caught in the weld metal. This discontinuity can appear at any specific point on the weld or along its full length, and/or on the surface or the inside of a weld. The result, regardless of the location, is always the same: a weaker weld. Inadequate shielding gas coverage is one of the most common causes of porosity. To correct this problem, first check the regulator or flow meter for adequate gas flow, increasing it if necessary, and check the gas hoses and the gun for leaks. Whether welding inside or outside, shield the arc and weld puddle from drafts with a welding screen. Next, confirm that the MIG gun nozzle is large enough for the application, as too small of a nozzle can prevent proper shielding gas flow. Keep the nozzle one-fourth to one-half inch away from the work piece, make certain it is free of spatter, and always use the correct contact tip recess. Slow your travel speed and hold the MIG gun near the bead at the end of the weld until the molten metal solidifies; pulling the gun away too soon can interrupt gas coverage and leave the setting weld vulnerable to the atmosphere. Additional causes of porosity include: using the wrong gas (always use a welding-grade shielding gas appropriate for the base metal and filler metal), using too much or the wrong type of anti-spatter (use the correct amount and type for your application) and extending the welding wire too far out of the nozzle (extend no more than one-half inch beyond the nozzle). Impurities in the base metal, such as sulfur and phosphorous in steel, or a dirty base metal can be further causes of porosity. If specifications allow, consider changing to a different composition of base metal, and always remove rust, grease, paint, coatings, oil, moisture and dirt prior to welding. Filler metals with added deoxidizers can help to “clean” the weld, but should never be solely relied upon to minimize porosity. Finally, replace any wet or contaminated shielding cylinders immediately. Undercutting occurs when a groove melts into the base metal next to the toe of the weld and the weld metal fails to fill that area. This discontinuity weakens the toe of the weld, increasing the chances of cracking. Correcting the problem is relatively simple: reduce the welding current, decrease the welding arc voltage and adjust your MIG gun angle toward the joint. Reduce your travel speed so the weld metal completely fills the melted-out areas of the base metal. When using a weaving technique, pause slightly at each side of the weld bead. When the weld metal fails to completely fuse the weld metal with the base metal or with the preceding weld bead in multi-pass applications, incomplete fusion can occur. Some people refer to this problem as lack of fusion. Generally, an incorrect MIG gun angle is the cause and you should adjust it accordingly. Follow these steps: If correcting the MIG gun angle does not remedy incomplete fusion, look to see if the welding puddle is too far ahead of the wire. If so, increase your travel speed and/or the welding current to correct the problem. Conversely, if you suspect insufficient heat input has caused incomplete fusion, select a higher voltage range and/or adjust the wire feed speed as necessary. Finally, always clean the surface of the base metal prior to welding to remove contaminants that may prevent the metal from fusing together. Another common MIG welding problem—spatter—occurs when the weld puddle expels molten metal and scatters it along the weld bead; this molten metal then cools and forms a solid mass on the workpiece. Excessive spatter not only creates a poor weld appearance, but it can also lead to incomplete fusion in multiple welding pass applications. Too fast of a wire feed speed, too high of a voltage setting, and too long of a welding wire extension, or stick-out, can cause spatter. Lowering the given settings and using a shorter stick-out can help. Like porosity, insufficient shielding gas and/or dirty base materials can cause spatter. As necessary, increase the shielding gas flow at the regulator and minimize drafts near the welding arc, clean and dry the welding wire, and remove all grease, dirt and other contaminants from the base metal. Other factors that can cause spatter are: the wrong size contact tip, a worn contact tip or the wrong tip to nozzle recess. Be certain you have the right contact tips, nozzles and recess parameters for the application. Excessive penetration occurs when the weld metal melts through the base metal and hangs underneath the weld. Excessive heat input is usually to blame for the problem. To correct this, select a lower voltage range, reduce the wire feed speed and increase your travel speed. Conversely, insufficient heat input can cause lack of penetration, or the shallow fusion between the weld metal and the base metal. Selecting higher wire feed speed, a higher voltage range and/or reducing travel speed are all viable remedies. Preparing the joint correctly also helps prevent lack of penetration—the preparation and design should permit access to the bottom of the groove and allow you to maintain proper stick-out and arc characteristics. Wire feed stoppages and wire feed system malfunctions can adversely affect the welding arc and create irregularities that may weaken the weld bead. Birdnesting, a tangle of wire that halts the wire from being fed, is a common problem. You can resolve birdnesting by flipping up the drive roll and pulling the wire back out of the gun. Next, trim the affected wire and re-thread it through the feeder and back to the gun. If the welding specifications allow, decrease the drive roll tension, use a larger diameter wire and/or reduce the distance the wire feeds (use shorter cables) to minimize the chance of birdnesting. Burnback is also very common. It results when a weld forms in the contact tip, and usually occurs because of too slow of wire feed speeds and/or from holding the MIG gun too close to the base metal during welding. To correct burnback, increase the wire feed speed and lengthen the distance of the MIG gun from the workpiece (the nozzle should be no further than one-half inch from the metal). Replace burnback-damaged contact tips by removing the nozzle and the contact tip (which may be melted to the wire), snipping the wire, installing the new contact tip and replacing the nozzle with one that has the appropriate tip recess for the application. Other causes of wire feeding problems include liner blockages, improperly trimmed liners (too short/burred/pinched) or the wrong size liner. To remedy these problems, replace any liner if you find a blockage, always trim the liner according to the manufacturer’s direction and be certain you are using the correct size liner for the welding wire diameter. Remember, quality MIG welds are the result of not only good welding technique, but also your ability to identify and solve problems quickly if they do occur. Continue arming yourself with some basic information and you’ll be able to tackle the most common problems associated with MIG welding without sacrificing time or quality.
There are regular job shops. Then there are job shops that go far beyond basic fabrication — ones that design, machine, laser cut, manufacturer and inspect specialty components from start to finish. Watson Engineering, Inc. of Taylor, Mich. is just such a one. What began as a one-person fabrication shop nearly thirty years ago is now a full-service manufacturer of prototype tubular and sheet metal components, along with products for the automotive and commercial industries. And whether its welding operators are retrofitting race cars with roll cages or manufacturing high-volume runs of heavy equipment components, Watson prides itself on one simple philosophy set forth by founder, Chuck Watson: “Customers come to Watson Engineering with problems they need help with – and we make the problems go away.” The company has been able to achieve this goal through a lot of hard work and even greater innovation. Not to mention, this job shop is lean. Every tool, every bin and every piece of welding equipment has its place — and that place has been chosen for maximum efficiency. In fact, the entire organization of Watson’s facility has been the result of all of its employees’ commitment to the company’s lean initiatives, from concept to painting and shipping. Not surprisingly, as part of its ongoing innovation and its lean initiatives, Watson decided to look as closely at its robotic welding cells, too. In doing so, they decided to convert to Tregaskiss’ TOUGH GUN I.C.E.® robotic MIG gun in order to solve a long-standing problem: finding a durable gun that could maintain its accuracy after a collision. They also added several of Tregaskiss’ air-cooled TOUGH GUN robotic MIG guns to other welding cells. After adding the products, they were surprised to find a few extra benefits that directly support their lean initiatives and have also contributed to a 25 percent increase in Watson’s overall productivity. Watson prides itself on the ability to produce components that have exceptionally intricate or complex designs. Not surprisingly, such designs can pose some particular challenges to the welding process, especially when the components are comprised of a wide range of materials and material thicknesses. According to Rafael Velasquez, robotic supervisor at Watson, in any given day the company may weld exhaust manifolds for an automotive customer, hood hinges for a commercial customer and thousand pound internal components for a heavy equipment manufacturer — sometimes in the same work shift and the same robotic welding cell. Not to mention, all the products undergo rigorous quality control testing (Watson even performs 100 percent lot tests on some parts), so quality is key and downtime is simply not an option if they are to create top notch products on a tight schedule. One of the biggest obstacles that Velasquez and his fellow Watson welding operators have faced over the years is finding a robotic MIG gun that could “take a hit without bending the neck” after a collision. Despite the best precautions, robotic welding collisions are a very real problem, resulting most often from tooling clamps not being secured. If the robotic MIG gun neck bends, it must be adjusted or replaced since the robot’s tool center point (TCP) will change and have a negative impact on the quality of subsequent welds. “We’re always changing parts and tooling,” explains Velasquez. “Unfortunately, you can bend two or three necks in a week because of it. Somebody would miss a clamp and leave it up. It happens.” After enough bent necks, downtime and just plain frustration, Velasquez opted to contact Watson’s long-time distributor, Dan Gnesda of Roy Smith Company in Detroit for help. Gnesda recommended the TOUGH GUN I.C.E. Robotic MIG Gun and the results, per Velasquez, have been worthwhile. Prior to converting to the TOUGH GUN I.C.E. robotic MIG gun, Watson used a competitive brand water-cooled gun, which Velasquez explains was quite costly and time-consuming to fix after a collision. Fundamentally, necks for water-cooled robotic MIG guns tend to be weaker than air-cooled designs and involve more work to replace, in major part because the water lines run internally through the power cable, gun and neck. To replace the water-cooled neck after a collision, Velasquez and his team needed to disconnect the neck from the gun and unhook the water lines by removing clamps that were crimped around them — a process that took about 30 minutes. Converting to the TOUGH GUN I.C.E. robotic MIG gun, however, seems to have offered Watson the best of both worlds: the durability of an air-cooled MIG gun and the cooling capacity of a water-cooled gun. I.C.E stands for ‘Integrated Cooling Enhancer’ and aptly describes the design of the gun, as it is a ‘hybrid’ between conventional air- and water-cooled designs. The TOUGH GUN I.C.E. robotic MIG gun features stainless steel water lines that run along the outside of the gun’s neck down to the nozzle, rather than through the neck like true water-cooled products. This design provides water circulation that keeps the consumables of the gun running cool, but because the lines are external (instead of running through the neck), the gun’s neck has more mass and is stronger, much like that on an air-cooled gun. According to Velasquez, the necks on the TOUGH GUN I.C.E. robotic MIG guns “can take the hit” most times after a collision, and in the event that the neck does bend, it can be replaced in about five minutes — a timeframe that fits nicely into Watson’s overall lean initiatives. The TOUGH GUN I.C.E. robotic MIG gun also features water shut-off valves at the I.C.E. connections and a quick-change neck feature. To disconnect the neck, Velasquez simply loosens a setscrew on the gun housing, disconnects the quick-change fittings for the water lines and slides on a new neck. After reconnecting the water lines and verifying his TCP, he can get the welding operation up and running again. “My emergency calls from Watson used to come through every other week with the previous gun, because of the crashes,” explains Gnesda. “After replacing the necks, there could be leaking or something else that was off. Now with the TOUGH I.C.E. gun, well, I hear from them every couple of months.” And because, the TOUGH GUN I.C.E. robotic MIG gun provides up to 550-amp capacity (at 60 percent duty cycle with mixed gases), it provides Watson with another solution that fits their goals for creating a lean facility: it can weld on a variety of material thicknesses. There is no need to change out robotic MIG guns to accommodate for the ever-changing flow of components that make their way through the weld cell each day — a factor that saves Watson money and time. “We have a lot of high amperage, high voltage welds. And we weld on thinner metals, too,” explains Velasquez. “Some of our components are thirty-millimeters thick and others are as thin as three mils. I can weld both. I just have to change out the wire.” As with the durability of the gun’s neck and the occasional changeover, being able to use the same gun for all its parts has contributed significantly to Watson’s lean initiatives. “There’s so much going on here with all the parts they weld, it’d be very easy for things to get out of control.” says Gnesda, “But these guys have a handle on everything. I think the I.C.E. is helping with that.” The goal of Watson’s lean initiatives has been to improve workflow, minimize downtime and, of course, improve productivity and profitability. After converting to the TOUGH GUN I.C.E. Robotic MIG Gun, and also adding several Tregaskiss® TOUGH GUN® robotic MIG guns to their other welding cells, Watson found that their equipment maintenance also became easier and they reduce their inventory, too — both benefits they had not anticipated. Velasquez first noticed that the total cost of maintaining the TOUGH GUN I.C.E. robotic MIG gun was substantially lower compared to the conventional water-cooled MIG gun Watson used previously. In addition to the fact that the necks have been more durable and easier to replace when needed, he found that the gun’s unicable has been equally robust. In fact, according to Velasquez, he only just recently changed out the original unicable that came with the TOUGH GUN I.C.E. robotic MIG gun two and a half years ago. “We’ve been running around the clock, six days a week each year with the same one,” he explains. “To change it, I just loosened a couple of screws, popped it out and put on the new one. With the addition of a new liner, I just connected the unicable back at the feeder. It took me fifteen minutes and we’re done.” Saving the cost of purchasing unicables on a regular basis has been a welcome benefit for Watson, as has its reduction in inventory for this and other MIG gun parts. Since Velasquez began using the TOUGH GUN I.C.E. robotic MIG gun and the air-cooled TOUGH GUN MIG guns for his other welding cells, he has also been able to reduce his inventory for necks significantly, too, as many are interchangeable. “I used to have so many necks in stock, sometimes about fifteen different ones. Now I’ve got three necks I can use on all the robots. I don’t have to have so much inventory to keep this place running,” says Velasquez. He’s also been able to reduce his consumables inventory. Both the TOUGH GUN I.C.E. Robotic MIG Guns and the standard TOUGH GUN MIG Guns operate on Tregaskiss’ Common Consumable Platform, meaning that the front-end consumables — nozzles, contact tips, retaining heads and liners — are the same for both guns. Velasquez explains that he uses standard and heavy-duty TOUGH LOCK® consumables for all the guns, depending on the thickness of the parts his robots are welding and at what amperage. He simply orders the parts that correspond to the different wires he uses between part runs. Velasquez also explained that when he changes over the contact tips on his robotic MIG guns, he then uses them for the semi-automatic MIG guns Watson uses in other portions of the facility. So what’s the bottom line of these and all the other benefits Watson has found with its lean initiatives? According to Velasquez, Watson’s lean initiatives — including the benefits brought forth from the TOUGH GUN I.C.E. robotic MIG guns and other Tregaskiss products — have combined to provide a 25 percent increase in the company’s productivity. The process is ongoing, of course, but it’s been made easier by the commitment of Watson’s employees who have all played a significant role in organizing the facility, from the concept phase of the many components it manufactures to the machining, storing and assembly of the parts. Having a durable, easy-to-maintain robotic MIG gun and minimizing Watson’s inventory has definitely helped improve workflow and reduce downtime, too. “We’re serious about lean,” says Velasquez. “We try to complete jobs from concept to finish within days. The I.C.E. and other Tregaskiss products have definitely helped us.”
The economy is in bad shape right now, but when it improves, the graduates of San Diego Continuing Education’s welding program will be well positioned to fulfill the need for skilled welders. Now in its 35th year, the school focuses on adult education for unemployed and underemployed San Diego-area residents. Its curriculum is narrowly tailored to the needs of local industries — specifically shipbuilding, construction and manufacturing. The school provides free training to any California resident and currently has 96 students and a waiting list of an additional 58 people. “Our program is set up to provide the student with experience on the same types of joint configurations, metal types and welding processes that they’re going to need when they enter the workforce,” explains welding instructor Bill Borinski. The program, which spans a minimum of 600 hours over 24 weeks, also prepares the students with the skills to obtain an AWS D1.1 (American Welding Society) Unlimited Certification by passing a visual and x-ray weld evaluation. Even with the school’s focused, industry-driven curriculum, there is still a vast amount of knowledge and skills to impart to the students, and the school strives to make every minute count. That, explains Borinski, is why it is so important for the school to have durable, time-saving welding equipment. “Downtime in business costs money — for us it costs knowledge,” he says. “If a student’s equipment is down, then he’s not learning. Our students have enough to concentrate on as it is, they shouldn’t have to worry about whether their equipment is working properly or not.” The school recently converted its welding labs to Bernard™ Q-Gun™ and Dura-Flux™ MIG Guns and Centerfire™ Consumables to prevent such problems. The guns and consumables came packaged with the school’s new power sources and wire feeders, and Borinski said he’s been very satisfied with the results. The program has been running the guns for 12 hours a day, four days a week, and there hasn’t been a single malfunction. The Centerfire consumables system has reduced student downtime and frustration, while also improving weld quality. In this open-enrollment program, students work on the material at their own pace until they master the skills required to graduate. New classes, which meet for 6.25 hours a day, four days a week, begin every month, and students can stop and start the program at their discretion. Students learn an AWS-certified curriculum in self-shielded and gas-shielded flux-cored welding on 3/8- to 1-inch mild steel using E70T-1 and E71T-8 welding wire. Students briefly learn the GMAW process, but the program spends the majority of its time providing specific skills that are needed immediately in local industries. They focus on building proficiency in all welding positions on butt, corner and T-joints. The school uses Bernard Q-Gun MIG Guns for its gas-shielded flux-cored and MIG training. Borinski noted that the gun’s curved handle reduces his students’ muscle fatigue after welding for long periods of time, and that the guns also improve their mechanical leverage, making it easier for the students to hold the guns in flat and horizontal welding positions. “What my students and I love about the Q-Gun handle is that when you put it in your hand, it’s already in a position to weld,” Borinski said. “If the MIG gun is putting strain on my students’ wrists, they’re going to be sore and miserable by the end of the day and they’ll probably lose some of their enthusiasm for a career in welding.” The Centerfire system further reduces his students’ educational downtime and frustration levels, Borinski said. By using a threadless contact tip with a large diameter tapered base that fits snugly into the diffuser and is locked in place by the nozzle, the Centerfire consumables make it nearly impossible for students to set incorrect contact tip recesses or for the tip to come loose inside the nozzle. “With our old brand of consumables, if we didn’t screw the contact tips in properly they would come loose and literally fly out of the end of the gun. That can really add to the frustration of a beginning welder,” Borinski said. While he is pleased with the guns and consumables, Borinski noted that it’s Bernard’s customer service that will keep him as a customer when their equipment eventually needs to be replaced. “To us, a gun is a gun,” Borinski said. “We can figure out on our own how it operates. Still, we were really impressed when a Bernard representative came out and offered to exchange any of our guns for free if the stock model didn’t perfectly fit our lab set ups.” Bernard’s Gun Exchange Program allows any one who receives a standard Q-Gun or Dura-Flux MIG Gun as part of a power source or wire feeder package to exchange the unused gun for a new gun with different cable length, neck, handle or trigger configurations. Bernard also provided Borinski with product information and support prior to and following his purchase to ensure the guns and consumables he ordered would meet his needs. “Sometimes the educational community gets sheltered from a lot of the outside activities that are going on. We don’t get exposure to the different equipment options that are out there,” Borinski said. “When Heidi Ewoldt, Bernard’s Inside Technical Sales Manager, called us and spent time explaining all of the equipment options and configurations available, it told us that Bernard wanted more than a quick sale. They were committed to our success.” “We’re running some pretty hot, high-amperage applications here,” Borinski said, “and we have had zero failures — zero internal issues, zero electrical issues. We haven’t even needed to change the liners on some of the guns.” Like Bernard, San Diego Continuing Education understands the value of strong partnerships and adapting its products to its customers’ needs. In order to meet the evolving demands of area industries, Borinski meets annually with an advisory committee composed of business and union leaders to discuss the skills and knowledge they look for in new employees. “If we taught what we wanted to teach and not what the employers in the area need, then we’re sending them people they can’t use and wasting our students’ time,” Borinski continued. “We must have our pulse on the industry in order to be a relevant educational institution.” In the last few years, Borinski said, the advisory committee has been asking for employees with “soft skills,” such as blueprint reading, teamwork training, lean manufacturing processes and other skills that go beyond laying a weld bead. “The job market is very competitive now,” Borinski said, “and those students with additional skills, who can add value to the organization, are going to have a significant advantage during the interview process.” That’s why the school partnered with the AWS to form a curriculum that provides students with the knowledge and skills they need to become AWS Certified Unlimited in FCAW upon graduation. The unlimited designation is a guarantee that the student can perform code-quality welds in the 1-G, 2-G, 3-G and 4-G positions using the FCAW process. This certification, combined with the schools blue print reading and teamwork curriculum, gives graduates a strong advantage when applying to one of the area unions, Borinski said. The school’s approach to welder training has resulted in numerous opportunities for its graduates in area businesses. One example is the school’s partnership with General Dynamics NASSCO, one of the San Diego’s largest employers. Through the partnership, General Dynamics NASSCO has hired over 400 of the program’s graduates in recent years. The main reason San Diego Continuing Education tried the Bernard guns and consumables was that they came packaged with the wire feeders and power sources the school purchased. Still, after using them without a single failure for the last 18 months, Borinski said one of the first questions he will ask when purchasing new equipment will be whether they accept Bernard guns and consumables. Luckily for him, Bernard’s products are adaptable to almost all major power source and wire feeder brands.
For some companies, choosing between an air-cooled or a water-cooled MIG welding system is pretty cut and dry. Mobile fabrication and repair companies that weld sheet metal for only a few minutes every hour will have little need for the benefits provided by a water-cooled system. Likewise, shops with stationary equipment that repeatedly weld at 800 amps probably won’t be able to find an air-cooled system that can handle the heat of the application. But for many companies, however, it’s not such an easy decision. Each type of cooling system has advantages and disadvantages, and deciding which is right for your company requires a careful analysis of the following factors: Keeping MIG welding equipment cool is necessary to protect the power cable, gun and consumables from damage due to the radiant heat from the arc and the resistive heat from the electrical components in the welding circuit. It also protects the operator from heat-related injuries and provides more comfortable working conditions. A water-cooled MIG welding system pumps a cooling solution from a radiator unit, usually integrated inside or near the power source, through cooling hoses inside the power cable and into the gun handle, neck and consumables. The coolant returns to the radiator where the radiator’s baffling system releases the heat absorbed by the coolant. The ambient air and shielding gas further disperses the heat from the welding arc. An air-cooled MIG welding system relies solely on the ambient air and shielding gas to dissipate heat that builds up along the length of the welding circuit. Air-cooled systems use much thicker copper cabling than water-cooled systems, which allows the cable to transfer the electricity to the gun without building up excessive heat from electrical resistance. By contrast, water-cooled systems use relatively little copper in their power cables because the cooling solution carries away the resistive heat before it builds up and damages the equipment. The welding amperage will be an important factor to weigh when deciding between an air- or water-cooled system. In general, air-cooled systems are better for low amperages and water-cooled systems are better for high-amperage applications. Air-cooled guns are available with ratings from 150 – 600 amps, and water-cooled guns range from 300 – 600 amps. These ratings represent the current loads under which the guns become so warm that they are uncomfortable for the average operator to hold. Because guns are rarely used to the limits of their duty cycle, it’s often a good idea to purchase a gun that’s rated to a lower amperage than the maximum to which it will be exposed. For example, a 300-amp gun can handle more than 400 amps and it is substantially lighter and more maneuverable than a 400-amp gun. Closely related to a gun’s amperage capacity is its duty cycle — the amount of time during a 10-minute cycle that the gun can operate at its rated capacity without becoming uncomfortably hot. Exceeding a gun’s duty cycle can lead to operator pain and will also reduce weld quality and decrease the service life of the gun and consumables. There is no industry standard for establishing amperage ratings based on duty cycle, so two guns both rated to 400 amps could have significantly different duty cycles. This makes it important for the customer to consider a gun’s amperage rating and duty cycle together in order to form an accurate assessment of the MIG gun’s capabilities. Welding all day long in an industrial or construction environment can take a significant toll on the hands, arms, shoulders and back (not to mention most other body parts) of a welding operator. A heavy, bulky and difficult-to-maneuver gun only exacerbates these aches and pains, and it accelerates the time they take to set in. One of the benefits of water-cooled guns is their size and weight. Because water is more efficient than air at carrying away heat that builds up from the heat of the arc and electrical resistance, water-cooled guns use less wire for their cables and smaller gun components, resulting in reduced operator fatigue. Although air-cooled guns are generally heavier and more difficult to maneuver than water-cooled guns, significant differences in gun design between manufacturers can also have a big impact on how quickly the gun contributes to fatigue. It’s a good idea to physically hold a gun to determine its comfort level prior to making a purchase. Because water-cooled guns require more equipment than air-cooled systems, they can be impractical for applications that require portability. Transporting the cooling system and coolant hoses of a water-cooled MIG gun can reduce productivity and cause unnecessary downtime. Water-cooled systems are most practical in applications where they will be stationary or moved very little. By contrast, air-cooled MIG guns are easily carried and moved from site to site within a shop or out in the field. Finally, companies must evaluate the cost of the two systems before making a purchasing decision. Doing so, however, is not as simple as looking at their respective price tags. In addition to the sticker price of the systems, companies need to consider maintenance costs as well as productivity and downtime costs associated with operator fatigue and equipment longevity. A water-cooled system requires the purchase of a coolant flow system (including radiator, pump, hose lines, etc.), which leads to a higher up-front cost than an air-cooled system. Because water-cooled systems require a special coolant solution in order to avoid mineral or algae build-up in the coolant lines and radiator, they involve more extensive maintenance and higher operational costs than an air-cooled system. Furthermore, coolant leaks can lead to equipment damage and weld discontinuities that add to the cost of owning a water-cooled system. In addition to being less expensive up-front, an air-cooled system also offers the advantage of being better suited to low amperage applications. Thus, for example, a company that needs to weld at 150 amps and 600 amps in the same weld cell can keep its costs down by purchasing a single air-cooled system rather than a water-cooled system for the high-amperage applications and an air-cooled system for the low-amperage applications. That doesn’t mean, however, that a water-cooled system is more expensive than an air-cooled system. As mentioned earlier, a water-cooled MIG gun is much smaller and more lightweight than an air-cooled MIG gun, which can help decrease operator fatigue and increase productivity over the course of a day. When set up properly, a water-cooled MIG gun can provide significant long-term cost savings compared to an air-cooled gun. The coolant in a water-cooled system also extends the service life of the consumables by drawing away the heat absorbed from the arc. Longer consumable life means less downtime for changeovers and lower consumables inventory. Unfortunately, there is no one-size-fits-all formula for choosing between an air-cooled and a water-cooled MIG welding system. Each company must analyze their welding operations and determine which type of system offers the benefits most important to them. Considering these factors — cost, worksite location, gun weight and operator comfort, duty cycle and amperage requirements — will provide a good start toward making a wise decision. Find an air– or water-cooled MIG Gun for Your Application
Worldwide, companies serving the automotive industry have faced a unique set of challenges in the last several years. Still, as the economy begins to rebound, each must find ways to maintain their productivity and profitability — often with fewer employees than before the recent recession. A large part of maintaining that productivity is to ensure high levels of uptime in the robotic welding operations. Conventional problems like spatter, burn-through and poor part fit-up often hinder such attempts, as do issues like managing large amounts of inventory and contending with downtime to service welding equipment. Unfortunately, there is no single answer to these challenges. There are, however, some considerations that may help reduce suppliers’ pains and assist in other interrelated parts of the process. The recent increase in demand for production is causing some automotive suppliers, especially those in North America, to make capital investments that they previously postponed during the recession. When possible, standardizing on a single brand and style of welding power source, robotic controller, and GMAW gun and consumables during this investment can streamline inventory and maintenance procedures. For companies in organic growth mode with new programs and/or Greenfield operations, this standardization can help in long-term equipment re-deployment to other facilities, as well as streamline the manpower learning requirements. For companies that are in acquisition mode, however, this standardization may not be feasible. Instead, these suppliers should, at a minimum, consider standardizing on a single brand and style of robotic GMAW guns and consumables to minimize inventory. Doing so can also reduce the risk of improper consumable installation, which can lead to unscheduled downtime to rectify. Many automotive suppliers rely on tandem welding processes as a means to generate greater productivity. In recent years, however, advancements in single arc pulsed technology have proven very efficient in providing faster travel speeds and minimizing spatter. This technology, which effectively lowers the average amperage level during welding (by regularly switching the current between high peak amperages and low background amperages), is also quite easy to operate. Given the reduction in workforce in the automotive industry, combined with an overall shortage of skilled welders, this less complex (but highly efficient) technology has already proven beneficial for many automotive suppliers. Automotive suppliers, particularly those with multiple locations, may want to consider purchasing their robotic GMAW guns, peripherals and consumables from a single source vendor or welding distributor. Having multiple vendors may appear to provide cost savings up front; however, a per-item approach can actually increase the total spend. Instead, by single sourcing a product line, a company is better poised to maximize their purchasing power with one vendor and gain loyalty discounts. The vendor may also be more inclined to aid in new efficiencies and technologies. Plus, a trusted single source vendor can often help automotive suppliers assess their total consumable and robotic GMAW gun usage, streamline inventory and reduce costly paperwork at the same time. In addition to standardizing equipment when possible, using welding products that minimize the opportunity for errors is an important part of keeping the welding process flowing and reducing operator error. For example, nozzle detection (i.e. that doesn’t increase cycle time) can eliminate the potential of excessive rework or scrap. Avoiding errors in equipment installation is also critical, as missing or incorrectly installed components on the front end of a robotic MIG gun can cause them to become electrically alive, causing premature failure and poor welding performance. When possible, suppliers in the automotive industry should work with equipment manufacturers and vendors or welding distributors who can engage regularly in best practice meetings. These meetings can occur by conference call or in person, and can help determine what practices in the welding operation are working most effectively and what areas need improvement. Open issues can be prioritized amongst a group for time-phased solutions. These meetings can especially help companies with multiple locations, even globally, to identify opportunities for changes that could positively affect other facilities. They are also an excellent platform for brainstorming error-proofing ideas and serve to open communication among the parties involved in the success of a company’s welding operation. Even though preventive maintenance or PM may have become a commonplace buzzword in recent years, the fundamentals are still critical to providing good welding performance and reducing unscheduled downtime in the automotive industry. Companies should always take care to inspect connections in the GMAW gun, wire feeder, consumable and ground cables on a regular basis. Replacing worn components during scheduled downtime (at the beginning of a shift, for example) can help prevent problems during production. As of yet, “predictive maintenance” —– technology that alerts when consumables need to be changed – is not available. In the meantime, however, companies can instead track contact tip usage to gain an understanding of how often these components need to be replaced. Non-subjective analytical processes should be used to benchmark component longevity and performance. During Best Practice meetings, “Coopetition” can be an integral part of maintaining an effective welding operation for the greater good of the customer. This term refers, in short, to cooperation that occurs between competitive equipment manufacturers. The reality of any welding operation is that the manufacturer of the robotic GMAW gun or welding wire may be in direct competition with the company whose power sources are in an automotive supplier’s weld cell. Even so, finding equipment manufacturers who are willing to work together to address problems in the welding operation is key to resolving issues when they arise. A problem with the contact tip, for example, is usually a “barometer” of other things happening in the process. In short, it is very often a symptom of a problem, as opposed to the root cause. Having partners who are willing to put aside competitive differences for the good of resolving problems like these is important to gaining good welding performance. As is typical in automotive “just-in-time” applications, suppliers want to reduce instances of work-in-progress (WIP) and keep parts flowing (Takt time). To continue that work flow but still allow for any instances of stoppage in a robotic welding cell, suppliers may consider building a buffer into production. For example, if a company has a production line of 40 welding robots, breaking that line into fifths (five sections of eight robots), allows them to address any instances of consumable failure while causing a stoppage of only eight robots instead of shutting down production on all 40. That buffer can mean a significant difference in terms of lost production and money. And while no single one of these considerations can ensure the levels of productivity and profitability to which automotive suppliers strive as production demands increase, they can be a step in the right direction. Automotive suppliers should consider working with a trusted welding equipment manufacturer and vendor to discuss a plan for assessing their robotic welding operation and identifying opportunities for improvement.
The automotive industry has certainly begun to show signs of rebounding from the economic downturn; however, companies are now being asked to “do more with less” as production volumes approach the levels of several years ago. More than ever, companies require operational efficiencies to maintain process flow and avoid unscheduled downtime of automated equipment. Commonly, arc-welding process challenges have a significant impact on achieving production goals and maintaining efficiency. Typical contributors to arc-welding process inefficiencies include poor part fit-up, tool center point (TCP) repeatability, spatter and managing consumable changes. Effectively managing these elements are essential if companies are to meet their quality requirements and fulfill a high-volume production demand. As the automotive industry continues experience an upswing in production—up 12.16 percent year-over-year through March 19, 2011 (Automotive News)— maintaining an effective and efficient operation will become even more challenging. Reductions in the workforce over the last several years have left the industry with fewer employees to monitor welding operations and the overall shortage of skilled welders has compounded the challenge. Whereas 10 years ago a large automotive supplier may have had one welding technician for 20 robots, today that ratio has increased to as few as one welding technician for every 50 robots – or more. Clearly, the lack of resources creates challenges but eliminating non-value-added activity (or that which doesn’t contribute directly to throughput) can help overcome those. Practices such as equipment standardization, preventive maintenance and product selection can promote a Leaner operation and provide opportunities to improve process flow and operational efficiency. In recent years, the consolidation of automotive suppliers and facilities has resulted in welding operations made up of multiple styles and brands of welding equipment, including power sources, robotic controllers, robotic manipulators and GMAW guns. The outcome is often a wide breadth of products to manage and, with fewer resources, an increased potential for costly errors and unscheduled downtime. Not surprisingly, in an industry that requires repeatable, high-volume welds—some up to 500 parts in a single shift—consistency is critical and any deviation in quality could result in downtime, scrap or rework. Ideally, standardizing on a single GMAW gun brand can help companies in the automotive industry avoid unscheduled downtime for changing out incorrect consumables or reworking quality issues. It can also reduce the amount of time spent managing inventory and provide a built-in poka yoke (mistake-proofing) system by eliminating (or significantly reducing) the opportunities for incorrect installation. Some companies have found that such standardization, along with a vendor-managed consumable system works well and contributes positively to their goal of maintaining process efficiency and equipment utilization. The process of standardization may take time—replacing older GMAW guns as they wear, for example—but in the long term it can yield positive results in quality, performance and cost. It also allows the production team to have one point of contact for technical support should questions arise about the performance of a GMAW gun or consumable, as opposed to having to contact multiple manufacturers. To help with the transition to one GMAW equipment supplier, front-end conversion kits are widely available and allow companies to standardize on a single brand of consumables, regardless of the type of GMAW gun being used. These kits are a good alternative to replacing an entire fleet of GMAW guns, while still offering the benefits of standardized inventory. In some cases, there is an opportunity to maximize the value of welding consumables by using the same contact tips and nozzles for semi-automatic applications (such as those for repairs or rework) after they are too worn for the robotic application, which further reduces inventory. Most welding technicians, supervisors or operators in the automotive industry will attest to the fact that proper part fit-up is a constant concern. But not only do the parts that move into the weld cell need to be of the proper dimension and fit, the GMAW welding gun and consumables being used also need to provide accurate, repeatable and durable performance. Robotic GMAW guns are intended to weld at the same location every cycle by providing a consistent tool center point (TCP). Some products are more durable than others but they all require preventive maintenance to optimize performance and prevent unscheduled downtime for replacing items like contact tips or liners. Air-cooled robotic GMAW guns are the most durable product available. Many applications in the automotive industry, such as suspension components, use thin materials—2 to 4 millimeters—that are ideal for an air-cooled robotic GMAW gun since the typical operating range is approximately 200 to 300 amps at an average of 60 percent duty cycle. Water-cooled products improve performance at higher duty cycles yet they are inferior to air-cooled products from a durability perspective. This is primarily due to the addition of water channels and other mechanical requirements of a water-cooled design. In the automotive industry, it is rare to experience applications that truly require a water-cooled GMAW gun. Even for end users welding thicker base metal (truck frames, for example), they are still likely to be within the comfortable range of an air-cooled GMAW gun. In some cases, however, the addition of water-cooling will help manage excessive heat and prolong the life of welding consumables (e.g., nozzles and contact tips). In these instances, there exists an opportunity to use a hybrid air-cooled/water-cooled gun. This type of product has the underlying construction and durability of an air-cooled robotic GMAW while offering some of the benefits of a water-cooled solution. Regardless of the welding application, it is important for companies to use the most appropriate type of GMAW gun for the job and properly maintain the equipment to ensure a maximum return on investment. Good preventive maintenance procedures include inspection of all connections in the entire system: GMAW gun, wire feeder and ground cables, and more. Other opportunities include regular inspections for proper wire feeding and proactively replacing worn components during scheduled downtime, rather than during production. Such activities can occur prior to a shift beginning and may help avoid unnecessary interruptions to welding during production. As the automotive industry returns to the production levels of several years ago, taking steps to standardize inventory, implement good preventive maintenance techniques and select the right product are means by which companies can become more efficient and “do more with less.”
Making the decision to automate your welding process isn’t something to be taken lightly. It requires a careful assessment of your current welding process, a detailed plan to automate and, in most cases, the ability to justify the capital expenditure—tasks that together can take months to complete. Still, automating your welding process can bring many advantages that make the work worthwhile. These include: increasing productivity, improving weld quality, and lowering material and energy costs, among other benefits. In many cases, you can also obtain a quick return on your investment through such advantages. The key to successful automation is to consider some important factors before purchasing and implementing your robotic welding system. Transitioning to an automated welding system can dramatically increase production; however, it should never been done impulsively. It is expensive and does not suit every application or facility. Instead, prior to implementing an automated welding system, work with an integrator or robot OEM to develop a plan that accounts for factors including: the part and volume to be automated, your facility and available personnel for overseeing the system. Completing an upfront evaluation of your current welding process, as well as the outcome you desire is a good place to start. It will also help you avoid implementing an automated welding system that requires constant supervision. After all, the goal is to have an automated process that requires only nominal supervision, while still improving productivity and weld quality. A good first step is to consider whether you need a fixed or robotic welding system. Fixed automation is extremely efficient and cost-effective, and works well for welding parts that requires straight or curved welds along a single plane. An example would be a lathe-type application in which a simple part is spun, welded and ejected from the process. Another example would be a straight-line weld, in which the torch advances, makes a six-inch weld and retracts to the neutral position in preparation for the next weld. Conversely, a robotic welding system features guns mounted on arms with articulated joints that can reach, rotate and pivot to gain access to the part. They can be programmed to complete more intricate welds than a fixed automation system. If you anticipate frequent job changes or need to weld complex parts, this type of automation can offer the flexibility to be re-tasked as needed. Also, think of your company’s future welding needs when determining which type of automation is best for you. For example, if you currently weld a part well suited to a fixed automation system, but you aren’t certain you will be welding that part three years from now, consider a robotic welding system. It can be reprogrammed and retooled to accommodate your needs in the future. Regardless of the type of automated welding system you choose, these systems are significantly faster than semi-automated welding, provided the process suits the application at hand. Simply put, your application needs to be repeatable. Parts with large gaps, fit-up or access challenges are best left to a welding operator who can weld in obstructed or precarious positions and compensate for such conditions. Similarly, parts that require intricate clamping and tooling to hold them in place will often hinder the productivity benefits of an automated welding system. Instead, if you are considering an automated welding system, be certain that the parts manufactured upstream are as simple and consistent as possible, and that they allow the robot to execute the weld repeatedly. Working with a robot OEM or integrator is a good way to determine if your parts are well suited to an automated welding system. Provide them with a blueprint or an electronic CAD drawing of the part you wish to weld. Doing so helps improve the quality of the planned weld and determine how the part and its tooling can be fine-tuned to optimize the automated welding process. Prior to automating, you should also assess the parts flow. For example, if you want to your automated welding system to relieve a bottleneck at the welding cell, then be certain that there are no delays in upstream part fabrication. Similarly, you should ensure that there is no rework required before sending parts to the welding cell or that the employees supplying parts to the robot can match the cycle time of the automated cell. After all, the efficiency of each of these situations directly affects efficiency of the automated welding system—if they are too slow, they can cause significant downtime and negate the speed sought through an automated welding system. If you cannot guarantee fast upstream workflow, you may want to consider an automation solution for upstream applications. These machines feature sophisticated part recognition systems that can pick up parts, manipulate them to the correct orientation and deliver them to the automated welding cell. These systems add to the expense of automating; however, they may be an option if you are concerned about the consistency and cycle time of your manual upstream processes. You might consider working with a third-party integrator to help you decide whether your facility suits the installation of an automated welding system. System integrators are knowledgeable about all aspects of facility modifications necessary for automation, including important safety regulations that apply in the fabricator’s region, country or state, in addition to those specified by OSHA and RIA (Robotic Industries Association). That said, the first step in assessing your facility is to determine your available space. Remember, the physical footprint necessary for a robotic welding system, as well as the room needed for the flow of raw materials is significantly greater than that of semi-automatic welding processes. By considering your available real estate, you can be certain that you have not only the physical space to accommodate the new system, but you can also avoid having to customize products, such as unicables, peripherals or torches to fit the work envelope. Instead, you can rely on standard products that will work within your allotted area. And, don’t worry if you have a small facility. There are still ways to make automation work. One option is to purchase fewer pieces of automation equipment that are capable of performing multiple tasks. Regardless of the size of your facility, you should also consider the power sources required to operate an automated welding system—a 480-volt three-phase power source is usually considered optimal. Also consider your gas and wire requirements. Due to the higher volume of welding possible with an automated welding system, you will need to purchase, store and place larger packages of wire (for example, 600 or 900 lb. drums compared to 40 lb. spools). In terms of gas delivery, limiting robot downtime is the top priority. Investing in bulk delivery of gas and using a manifold system can eliminate the downtime associated with frequent bottle change-outs and is key to adding to the productivity of an automated welding system. Automated welding systems need human supervision and maintenance. When considering whether to automate your welding system, you should evaluate the skill set of your available welding operators, as well as the resources you have for training them. The personnel who are most viable for training (and ultimately the oversight of your robotic welding system should you proceed with the purchase) are skilled welding operators or those with previous robotic welding management experience. These individuals should, after training, have the skills to program the robot and to troubleshoot the automated welding process as needed. They should also be able to perform routine, preventive maintenance on the system, as it can significantly decrease downtime in the long term and increase the life of the system and its components. Consider vetting robot OEMs to determine the availability and costs associated with the training of your personnel. Typically, robotic integrators and OEMs training, which usually lasts one to three weeks depending on the certification level desired. Also, look for robot OEMs or integrators that have resources available after the training has been completed. These resources may include online tutorials or troubleshooting information, additional onsite training and/or service team members you can reach by phone with any questions you and your team may have. Finally, before transitioning to automation, you will need to justify the expense—either to your superiors, or to yourself if you are the decision maker. To do so, first consider whether the volume of parts you need to produce necessitates automation. Remember, the key benefit of an automated welding system is the ability to produce high volumes of quality welds. If you have a smaller facility with lower runs of parts, however, you may still be a good candidate for an automated welding system. With the help of the integrator or robot OEM, you may be able to select two or three smaller volume applications and program a robot to weld those different parts instead. Calculating payback requires you to assess your current part cycle times and compare them to the potential cycle times of an automated welding system. Determining this volume is a critical factor to estimating your potential return-on-investment, as up to 75 percent of the cost of a semi-automatically welded component is the labor. That said, even if you will produce the same number of parts, you might be able to justify the investment by the amount of labor you can reallocate elsewhere in your operation. Specifically, you can use the skills of your semi-automatic welding operators toward the completion of challenging welds that cannot be completed with an automated welding system—adding further to your overall productivity. Smaller companies that transition to an automated welding system, or those with frequently changing parts, often seek a shorter payback period (no more than 12-15 months) in order to justify the investment. Conversely, if you know that your production needs will not change for years, you may be able justify a longer payback period. Remember, the key to successful automation is planning. Work with a trusted integrator or robot OEM to assess your current welding process and to determine the best type of automation for your application. Don’t forget to consider your available personnel, options for training and any facility accommodations needed for a new automated welding system. Each of these factors is crucial to realizing the advantages of automation and can help you achieve a faster return on the investment.
Measuring the value of a welding gun can be difficult when the gun is working properly. It’s those times when the gun is malfunctioning and you’re losing valuable production time trying to clear out a bird’s nest, change your fifth contact tip of the day or repair a shorted out power cable that the importance of the welding gun becomes clear. As one of Arizona’s premier handrail fabricators, Hot Az Hell Welding and Fabrication learned first hand the value of a welding gun when they began upgrading the majority of their equipment from Stick to the flux-cored process. While upgrading, company president Shawn Moreland didn’t think much about the flux-cored gun he would purchase and made his decision strictly based on price. Then, he and superintendent Chris Rice worked side-by-side on a project while Rice used a Bernard Dura-Flux™ gun instead. “I would be getting birds nests several times a day with the gun I purchased, and each time it would happen, Chris would have to come over and fix it for me,” Moreland recalls. “It would take him off his work and up to 10 minutes to fix. That whole week Chris didn’t have a single birds nest with the Dura-Flux, and eventually we realized it was the gun that made the difference.” They outfitted Moreland’s wire feeder with a Dura-Flux and he didn’t experience a single bird’s nest for the rest of the job. “We just threw the other gun away,” Moreland said. “After I got a chance to use Chris’ gun, I was 100 percent sold on Bernard.” As pleased as they were with the lack of downtime from repairing birds nests, Rice and Moreland have been even more impressed with the gun’s durability. “It gets pretty hot here, and the last thing my guys want to worry about is babying their welding equipment, so we end up putting the guns through some serious abuse,” Moreland explained. “I know you’re not supposed to, but we use the guns to drag our feeders all over a job site and the fact that they’re still working really tells me something about the quality of the gun.” Quality is something that Moreland, Rice and the other three Hot Az Hell employees, know a lot about. In over 20,000 linear feet of hand rail fabrication, they can boast that they have not had to make a single repair. “We have a flawless record with the register of contractors,” Moreland said. “We have dozens of general contractors that recommend us for federal, state, local and even residential projects, and we owe a lot of that to Chris’ commitment to high-quality welding.” The company specializes in hand rail fabrication, but also takes on a wide variety of welding jobs, including a recent project in which they welded five railroad cars together to form a bridge over the Central Arizona Project (CAP) Canal. Given the company’s history, it’s no surprise that an exceptional welding track record grew out of exceptional personal chemistry between Moreland and Rice. The two men became best friends while working as first line supervising foremen at an Arizona gas utility. “We formed a really tight bond back then because we were the only two that we could rely on within the company,” Moreland recalls. Both Moreland and Rice left their jobs to start their own businesses within a year of each other. Moreland said he frequently attempted cajoling Rice into working for him, and finally in 2006 Rice acquiesced and closed his business in order to join Hot Az Hell. From modest beginnings in 2006, Hot Az Hell has grown from an annual gross $160,000 their first year to projections of over $800,000 in 2009 — all with a five person staff. As of early 2009, the company was booked solid through mid-2010 with contracts to install over 32,000 linear feet of hand rail, including two of the largest projects in the Arizona Department of Transportation’s history — the widening of U.S. Highway 60 in Mesa and the Hoover Dam Kingman Highway expansion project. Moreland said the friendship among his employees, and their willingness and ability to take on virtually any of the work the company performs is a major contributor to their success. “We’re a very tight knit group. We’re more like a family than a company, but we also understand the business aspect of it as well,” Moreland said. “With a company our size, especially with the economy in a recession, everyone needs to be very versatile and able to take on whatever tasks the job demands.” Another key to the company’s success is Moreland’s confidence in the fabrication and welding expertise of Rice, the company’s ‘MacGyver.’ For his part, Rice said he is continually on the lookout for products and technologies that increase the company’s productivity and operator efficiency. As an example, during the recent CAP Canal project, the company was told they would need to use 7018 stick electrodes to weld the rail cars together, but after the first day of welding the pan decking using the stick electrodes, Rice asked the project inspector if they could use a structural flux-cored wire. They were allowed to use the flux-cored wire, and the following day, they produced four-times the welds of another crew member who was still using the 7018 rods. “They were losing several thousand dollars an hour every day that they couldn’t get their cranes across a 22-foot diameter pipe,” Moreland recalls. “By the end of the project, the general contractor told us, ‘We owe you guys big time.’ They didn’t think there was any way that we were going to be able to finish the bridge in the time that it took us.” Rice and Moreland apply that same focus on productivity and efficiency to purchasing their flux-cored guns. For them, a great welding gun doesn’t so much speed up production as it avoids becoming an obstacle to production. That means minimizing downtime associated with contact tip changeovers, reducing operator fatigue and providing smooth and consistent wire feeding while enduring large amounts of mechanical and heat stress. The majority of the hand rails they weld are two-inch, schedule 40 mild steel pipe. Rice said for the .045-in. flux-cored wire he uses he sets his welding generator at 25 volts and about 110 inches per minute wire feed speed. They use a voltage-sensing wire feeder that provides the ability to work up to 400 feet from the welding generator (compared to roughly 75 feet with a remote control wire feeder). Given the heat and abuse that flux-cored guns are exposed to in normal environments, to say nothing of the brutal Arizona desert heat and landscape, finding one that simply allows them to keep welding is no easy task. Once they put the Dura-Flux gun to the test, however, they knew their search had ended. “We were on a job in Wickenburg (Az.) this week, and it was about 100 degrees out and we were working on a steep, 50-foot tall embankment,” Rice said. “After working all day in that heat, we were dragging our feeder by the gun up hill through rocks and dirt, and that’s pretty much what we’ve been putting the gun through on a regular basis. So far, there have been no problems with the gun or the consumables.” Moreland echoed that sentiment, recalling a recent bridge job. “There was only about four feet of clearance, so you had to hunch over and drag your machine every time you finished a weld and needed to move,” Moreland said. “When you’re hot and tired and working your butt off, you’re not going to be too careful with your equipment. These guns have been used hard and they’re still going strong.” One of the features of the Dura-Flux that allows it to endure the abuse to which Rice and Moreland subject it is an industrial-quality strain relief on the back end of the power cable. The high-tension strain relief protects the sensitive parts of the cable—where it connects to the gun and the power pin—from severe bends that could damage or fray the copper wiring in the cable or create a kink in the liner. Another key factor in maintaining high productivity rates is avoiding downtime caused by burn backs, when the welding wire fuses to the contact tip, or bird nests, when the welding wire becomes blocked and forms a tangle resembling a bird’s nest inside the gun, cable or wire feeder. “It costs us money and impacts our ability to complete a job on schedule whenever my guys have to stop welding to deal with a bird nest or to change contact tips,” Moreland said. “Compared to the Dura-Flux, the other gun we tried got dirty very easily, and that resulted in frequent burn backs and bird nests.” “On a recent project, we had over 200 feet of three-rail hand rails, with a total of 320 welds, and the only tip I changed was my fault because I mis-stepped and stuck it to the pipe,” Rice said. “That was 27 straight hours of welding without a single problem with the gun or tip. To me, it’s pretty obvious that the Dura-Flux gun is the best choice for our operation.” Although it’s difficult to measure the impact that the Dura-Flux gun made for Hot Az Hell, what is certain is that it is a much smaller impact than their previous gun brand would have made — and that’s a good thing.
The Road to Welding Automation
The Road to Welding Automation
Why and When to Take the Journey
What’s the Benefit?
quality, increase productivity and help address the shortage of
skilled welders.Repeat That?
Robotics or Fixed Automation?
Ready to Automate?
Learn How Peripherals Can Maximize Your Robotic Welding Performance
Don’t Be Marginalized
Learn How Peripherals Can Maximize Your Robotic Welding Performance
the life of the robotic MIG gun and its
consumables, and save companies
money for extra parts.Get a Grip
Making the Cut
Most wire cutters are designed to cut a range of different types of welding wire, including stainless steel, flux-cored and metal-cored, usually up to 1/16-inch diameter. They can often be mounted on a nozzle station (to be discussed later) or remotely located to be used as needed.Inspected and Ready to Weld
of an impact by signaling to the robot
to stop weldingCleaned, Sprayed and Spatter-Free
No Peripheral Decision
Is Automation Right for Your Operation
Is Automation Right for Your Operation?
Considerations to Make Before Investing
Automation Advantages
Parts Should Be Easy to Weld
Justify Automated Solutions with High Part Volume
Evaluating the Facility
of raw materials are greater than that of semi-automatic welding processes. Although welding automation can consume large portions of plant real estate, small facilities still can make automation work by purchasing fewer pieces of automation equipment that are programmed to perform multiple tasks. They can facilitate this solution by outfitting robots with various toolsets that enable them to work on diverse jobs while occupying a smaller footprint.Supervision of the Automated Cell
Prior Planning Prevents Poor Performance
Additional Information: Fixed Automation Versus Fully Automated
5 Tips for Improving Robotic Welding
5 Tips for Improving Robotic Welding
1. Select the Right Wire
2. Choose the Right Consumables
3. Consider a Front-Load Liner
4. Select the Right Filler Metal Package
5. Select the Right MIG Gun
Additional Resources
Automated Intelligence: Deciding Whether Automation is Right For You
Automated Intelligence:
Deciding Whether Automation is Right For You
1. Why Automate?
2. Payback
3. Whether to Automate
4. Your Automation Options
5. Automation Componentry
6. Planning for the Future
7. Throughout the Journey
Final Thoughts
Simple Ways to Protect Your Robotic MIG Gun
Simple Ways to Protect Your Robotic MIG Gun…
and Your Overall Investment in Automation
companies (regardless of their size or arc
count) should consider a preventative
maintenance program scaled to their
specific process.The Who, Why and Whens of PM
Getting Down to the Specifics
schedule a liner replacement as required. Replacing it prior to a failure prevents unplanned downtime to remedy wire feeding or quality problems later.Parting Thoughts on PM
Choosing the Right Robotic Gun for MIG Applications
Choosing the Right Robotic Gun for MIG Welding Applications
including an air-cooled model (as shown
here), can help ensure good weld quality,
and reduce equipment and maintenance cost — factors that lead to a good return on investment and greater productivity.Staying Cool with Air-Cooled Technology
Just Add Water
offer high-amperage capacity for applications
requiring prolonged periods of welding.An Option in Between
offer the durability of an air-cooled
model gun with the greater cooling
capacity of a water-cooled one,
making them an ideal fit for welding
multiple thicknesses of materials.Protecting the Assets
Understanding MIG Welding Nozzles
Understanding MIG Welding Nozzles
insert, as shown in this cut-away, can help extend
the life of the consumable. The brass insert,
in particular, helps maintain the inner diameter
of the nozzle and reduce wear.Selecting the Right Shape of Nozzle
Welding Application Nozzles Considerations Welding Current
High Heat
Limited Weld Access
Heavy Spatter Generation
Using Nozzle Cleaning Stations
Selecting the Best Material
build-up, as seen here, and cleaning it
properly can help extend the life of the
consumable. Adding anti-spatter can also
help prevent build-up.Proper Storage, Handling and Maintenance
Handling, Installing, and Maintaining GMAW Consumables
Handling, Installing, and Maintaining GMAW Consumables
Tips to Follow and Pitfalls to Avoid
properly can minimize downtime and costs.The Heat Factor
Using Anti-Spatter Solution
Storing and Handling Consumables
spatter buildup shown hereEstablishing and Maintaining Good Connections
Trimming Liners Correctly
manufacturer’s recommendation
for proper trimming and
installation instructions. Also
be sure to wear gloves when
handling the liner to avoid
contaminating it.Minding the Contact Tip Position and Nozzle Size
Things to Remember
Troubleshooting Robotic Welding
From Consumables to Cables:
Troubleshooting Robotic Welding
system, it is critical to identify the problem
as quickly and accurately as possible. Look
first at the variables that have most recently
changed, as these may be the culprits.Poor Consumable Performance and/or Premature Failure
Premature Cable Failure
Poor Wire Feeding
help extend consumable life. Should any
problems occur with the equipment,
check that the reamer is positioned
accurately and is applying the correct
mount of anti-spatter solution.Poorly Performing Peripherals
Trouble with TCP
Welding operators, however, shouldn’t assume that welds that are off-location are always caused by an incorrect TCP. In some cases, they can be the result of improper fixturing, fixturing that allows the part to move or a loose robot base. Or there may be a variation in the part itself.Final Considerations
Selecting, Installing and Maintaining a Through-Arm Robotic MIG Gun
Selecting, Installing and Maintaining a Through-Arm Robotic MIG Gun
robotic MIG gun, it is important to
carefully select and maintain the gun,
and also to follow the manufacturer’s
instructions for installation.Selection
Installation
When installing a through-arm robotic MIG gun, allow approximately
1.5 inches of slack to prevent undue stress on the power cable
and power pin, and minimize the opportunity for damage
to either component. Maintenance
Should You Automate?
Should You Automate Your Welding Operation?
Considerations for Making the Decision
with a competitive advantage by providing better weld quality
and greater productivity compared to a semi-automatic
welding process.The Benefits of Automated Welding
The Best Applications for Automated Welding
Process Flow is Important
Quality Matters
Shift in Skill Set
The Next Step
Consumables for Robotic Welding
How to Choose Robotic Welding Consumables
What you should know to improve performance and reduce costs
Mind Your Extensions and Connections
of an automated welding system, but they
can have a measurable impact on
downtime and day-to-day costs. Be
certain to carefully select and maintain
them to get the best performance
and minimize downtime.The Impact of Welding Wires on Contact Tip Selection
What is Your Mode of Welding?
Selecting the Right Nozzle … and Maintaining It
and contact tips.Other Considerations
Is Poor Conductivity Impeding Your Welding Performance
Is Poor Conductivity Impeding Your Welding Performance?
Accurate Troubleshooting
The Basics: MIG Troubleshooting
The Basics: MIG Troubleshooting
Keep Covered
Don’t Be Undercut
Keep Track of the Heat
All About Wire
No Cure-All
Related Articles
Detroit-Area Company Increases Productivity and Supports Lean Initiatives with New Robotic MIG Gun
Detroit-Area Company Increases Productivity and Supports Lean Initiatives with New Robotic MIG Gun
has helped Watson minimize downtime for neck
changeover, and it offers the welding capacity to weld
on a variety of parts and part thicknesses.Time to Fix What’s Broken
Durability, Flexibility and Accuracy
creates the tooling necessary to weld all
its components successfully.
Watson, the company is “serious about lean” — so
much so that they have a dedicated workforce for it.Ownership and Inventory Made Easy
components, along with products for the automotive and
commercial industries — all of which are carefully and neatly organized on shelves and in bins for maximum efficiency.Lean and Productive
Strong Bond and Strong Community at San Diego Continuing Education
Strong Bond and Strong Community at San Diego Continuing Education
Partnering for Success
Reaching out to the Community
Air-Cooled vs. Water-Cooled MIG Gun: Which is Right for You
Air-Cooled vs. Water-Cooled MIG Gun: Which is Right for You?
First Things First
Amperage Requirements
Duty Cycle
Gun Weight and Operator Comfort
Worksite Location
Cost
Conclusion
Thoughts for Improving Welding Operations in Today’s Automotive Industry
From Technology to Technical Support:
Thoughts for Improving Welding Operations in Today’s Automotive Industry
into the welding process can help ensure the necessary uptime
for automotive applications.Equipment Standardization
Single Arc Pulsed Technology
Streamline Vendors
Error Proofing
Best Practice Meetings
Preventive Maintenance
Coopetition
Built-in Buffers
Addressing Welding Challenges in Today’s Automotive Industry
Addressing Welding Challenges in Today’s Automotive Industry
Well-Managed Inventory Equals Greater Uptime
of best practices can help automotive companies “do more with less.”The Right Equipment Maintained Properly
Meeting the Demands
Is it Time to Automate? 5 Factors to Consider
Is it Time to Automate?
5 Five Factors to Consider
Factor #1: Plan Accordingly
and creating a detailed plan is key to gaining the many
advantages of an automated welding system.Factor #2: Evaluate Your Application
Factor #3: Assess Your Facility
cost of purchasing larger wire packages and the
appropriate storage areas for them.Factor #4: Determine Your Available Personnel and Training
Factor #5: Justify the Expense
Final Thoughts
Handrails in Hell, Arizona
Handrails in Hell: Hot Az Hell Welding and Fabrication Puts Dura-Flux to the Test
The key to success
Everyone at Hot Az Hell Welding and Fabrication can perform multiple jobs, one of the secrets to their rapid growth and success since being founded in 2006.Focus on efficiency
Reliable equipment equals increased productivity
The Dura-Flux recently allowed Hot Az Hell Welding and Fabrication to install 200 linear feet of three-rail hand rails with only a single tip change – which was attributed to operator error.
