- November 20, 2011
Understanding the benefits and building the case for the investment
By Brian Doyle, sales manager, Miller Welding Automation
The thought of converting to an automated welding system can be intimidating, even to the point that it causes the decision makers to disregard the process altogether.
In fact, statistics show that approximately 86 per cent of companies with 10 or more arcs still haven’t invested in automated welding. More than half of them likely won’t ever make the investment. But what about the remaining companies? How can the decision makers determine if automated welding is right for their company?
First, companies with regularly repeatable parts that are the appropriate size for an automated cell may want to consider the change to automation. The benefits can be considerable, both in terms of increasing productivity and improving quality. Often, automated welding also allows companies to more aggressively and accurately bid work, and it can help expose inefficiencies elsewhere in the welding process that need to be rectified.
Consider the following suggestions for investing in an automated welding system and making the conversion.
Robotics: Eliminating variation and increasing throughput
One of the main goals of automated welding is to eliminate variation and increase throughput. Once a company drives variation out of the welding operation, it can drive costs down and produce a higher quality product. To achieve this goal, however, it is critical that the processes upstream of the robot are capable of producing parts that are consistent. It is important to remove variables such as part fit-up, size differences and gaps before implementing an automated welding system.
To assist with eliminating variations, robots today also have the ability to adjust the tip-to-work distance and keep that constant over the length of a seam, and they can better control the torch angle to minimize variability. In the past, a robot operator would pick a torch angle that looked right. Now, the robot’s teach screen can display this information, helping eliminate the guesswork and ensure greater success in the welding operation.
Eliminating waste and rework
Automated welding systems create noticeably less spatter than a welding operator, and the process can be continuously refined to the point where it is almost eliminated altogether. Companies that currently employ laborers to grind or chip spatter after welding are creating unnecessary rework and may want to consider automation as a means to eliminate this step in the welding process. The goal is to prevent a situation that causes laborers to engage in more physical work to the part, as it generates unnecessary costs and takes up time that could be spent producing more parts.
Man vs. robot
When considering whether to automate, companies need to determine what a human does well compared to what a robot does well. Manual welding operators are good at making judgment calls and adapting to variations. A robot, however, is not good at judgment; it is good at repeatability.
For example, a robot can weld over a gap, but only if the gap is the same every time. If the whole part moves, a robot can typically find it with touch sensing, or if the part curves or has some distortion, a robot can usually determine that through seam tracking. But if a part has a ¼-in. gap one time and a tight gap the next time, welding it successfully will require adaptation and the judgment of the manual welding operator. To be successful, companies have to take judgment out of the equation in order to make a robot’s work repeatable and gain the benefits of an automated welding system.
Many companies may be intimidated by the idea of adding an automated welding system because they don’t know the physical space requirements. There may be some concern about needing to rearrange the facility, adding additional infrastructure to an existing building or creating an entirely new space for the weld cells. In some cases, those tasks may be necessary. However, robot manufacturers also offer pre-engineered robotic welding systems that include almost everything needed to start welding. These systems can be dropped right down into existing workflows and put into operation. They require minimal training and much of the basic tooling that is already being used can remain. It is best to work with a robotic integrator to determine the specific requirements for each automated welding operation.
When considering whether to automate, remember the importance of training. Companies need to determine whether they have the time and resources to supply the welding operators with training, and continue educating them about advanced techniques. Continued training is important, since it helps teach the welding operators some of the finer nuances of the system. Robotic integrators typically work with most first-time users to do in-house training after the installation and are available at request for future training.
While every company is structured differently, pushing responsibility for the automated cell down to the operator is key to achieving the advantages of automated welding. Companies should have someone with welding experience to oversee the system - someone who understands how the weld reacts to torch angles and positioning, and understands the welding process and its limitations. Putting a true welding operator in charge of the cell also upgrades his or her job and provides a sense of ownership, increasing the likelihood of employee buy-in.
Calculating the payback on an automated welding system is critical when making the decision whether to invest. It can also be difficult to do without examining each operation individually. A general ratio to use is 3-to-1: If a welding operator can make 100 parts per shift, that same operator feeding a robot will make 300 parts per shift. Using that 3-to-1 ratio as a baseline means one robot can do the work of three people. Given this ratio, some may argue that implementing an automated welding system will eliminate jobs. However, that is not the case. Instead, the efficiency of the system can allow companies to grow their operations, add more staff, more capabilities, and ultimately, become more competitive in the market. Competition creates growth, and that is the benefit that an automated welding system provides - especially taking into account the lack of skilled welders coming into the industry today. Many companies find they can sell, bid and gain more work because the automated welding system is operating more cost effectively and faster.
Top image: Miller Welds: As a general rule of thumb, a welding operator running a robotic cell can produce three times as many parts when performing the work manually.