Integrating Advanced Welding Automation

Mitigating the challenges of welding automation in high-mix, low-volume manufacturing means proper preparation, implementation strategies

Editor’s Note: This article is based on Doug Schindel’s presentation at the CanWeld Conference 2013, sponsored by the Canadian Welding Association (CWA).

Implementing modern manufacturing technologies is essential to the competitiveness of manufacturing firms in Canada. Weldco Companies, for example, has integrated advanced welding processes, automation, and robotic operations into our engineering designs and manufacturing operations for several decades.

Weldco Companies has been in operation since 1945 and comprises three business units: Weldco-Beales Manufacturing, Weldco Hydra-Lift, and Weldco Heavy Industries. The company has facilities and offices across Canada and the U.S. with 300,000 sq. ft. of combined manufacturing space. Weldco also currently employs more than 400 people.

Weldco-Beales designs and manufactures heavy equipment attachments for the construction, natural resource, scrap recycling, and road maintenance industries. The Weldco Hydra-Lift division manufactures truck-mounted cranes, and Weldco Heavy Industries is a large steel fabrication and repair facility.

High-mix, low-volume product lines create challenges to achieving a timely ROI for welding automation.

Successful implementation is built upon communication, mutual understanding of expectations, and proactive coordination between the manufacturing and engineering teams. Key challenges that must be explored include automation cell design limitations, robust implementation strategies, and understanding how shop culture must change.

Additionally, considerations for improved training and coordination between industry and academia need to be discussed.

Before You Start

Before you start down the path to welding automation, you need to have a strategy and an implementation plan in place.

If you are considering welding automation, this plan will keep you on track and reduce the number of unexpected pitfalls that you encounter along the way.

The implementation of automated welding technology is quickly becoming a must-have for Canadian manufacturers because their competitors are automating this process, or already have.

These competitors are not only here in Canada and the U.S., but global. The security of limited competition is gone, and you must learn to cope with other countries’ lower cost of labor, more elaborate government incentives for manufacturers, and a level of automation that often exceeds our own.

Chances are you automated your machining processes long ago. Now it is time to tackle your welding.

The level of automation needs to be suitable for the application at hand. In fact, robotics is not always the best solution, and other options should be considered.

Options other than robotics can include machine welding, a track and drive pinion that is usually in a straight line; manipulators used with a foot pedal and manual welding; and hard automation, which does provide some benefits, but has very limited flexibility.

Before making the investment, conduct a thorough evaluation of your application to maximize ROI, keeping in mind worker safety, productivity, and quality.

Worker Safety

Improved control of fabrication hazards is achieved with a truly automated system, and a proven, proactive safety program is becoming increasingly more important. Benefits to worker health include:

  • Less manual handling of components by overhead cranes. This keeps workers safe from unplanned falling material.
  • Separating the welder from the weld zone. Such separation reduces worker’s direct exposure to fumes and radiation.
  • Reduced absenteeism. Worker fatigue is lessened from strenuous activities, such as welding near high temperatures, which is typical in very large alloy components.

Scheduling and Productivity

Job scheduling and overall process productivity improvements are two easily identifiable benefits to an automated welding system.

Increased throughput and improved duty cycle (arc time) will both be accomplished. In addition, completing tasks in-parallel reduces cycle time and setup and teardown times. Productivity increases greater than 2:1, even up to 5:1 or more, can be achieved, depending on the application.

Quality

The demands for better weld joint fit-up forces improved upstream material preparation processes, including the production of better-quality welds. With an automated system you should expect more reliable and consistent weld quality.

Cost

Lower variability and total cost reductions can be seen following installation. The robot, after all, does not stop between welds, slow down over time, or otherwise reduce productivity. It is dependable, taking no sick days, holidays, or breaks. In fact, it will work unsupervised. Robotic welders systems frequently operate at night, in the dark, when no people are in the building. This means that your arc-on time will be maximized.

Automation Strategy

In terms of automation strategy, the employees are the most important variable in the success of any implementation. This also is an opportunity for cross-training in a lean operation.

Simply put, automation is the future, so it is better to learn now.

The design staff and operators need to be part of the automation system’s design and commissioning. The earlier they get involved, the more smoothly the process will unfold.

Qualified, certified welders are in high demand, but trade certification is not required for operators of robotic systems. The needed aptitude in computing and programming has and is growing in the new workforce generation, however.

The strategy conversation quite often centers on product size, and a couple of questions need to be asked. They are:

  • Is the part too large or heavy to make automation unfeasible?
  • Does it require a robot, or should it be manipulated by automatic positioning equipment?

In addition, large parts have long, complex programs that may or may not make the automation process financially viable.

Your arc-on time strategy needs to change if you add automation to your shop.

Parts requiring a short arc-on time (a low percentage of total cycle time) actually can be an advantage in welding automation. A robot cannot weld any faster than a human welder, but there are tremendous savings in air time (those minutes when the welder is not welding), and this is even more evident when dual manipulators or parallel operations are part of the automation.

Upstream prep and fit processes are very important to the success of any automated welding system. The accuracy of the burning and forming equipment is paramount, and you need accurate repeatability that is not always necessary with manual processes.

You also will need more labor to feed the increased capacity of an automated process.

It all starts with the material, however. Material condition, such as mill scale on the plate, must be taken care of first.

If all of these strategy requirements are met, you will get more consistent costs and operational times, and a more predictable operation.

Implementation

Several factors must be taken into consideration when it is time to start production after the installation of the automation system. They include:

1. Training. Don’t cut corners during the training phase. This phase should involve more than just the operators – production engineers, design engineers, and supervisors all need to be up-to-speed.

2. Balance production. Feeding the appropriate amount of work to the robot is important to properly manage all work orders and work-in-progress.

3. Fixturing. You need to have in-house knowledge and capability if you are going to have many fixtures because they are expensive. It’s good advice that for each dollar spent on the robot, invest another dollar in fixturing.

4. Upstream/downstream activity. Your upstream and downstream operations will need to be reassessed to best adapt to the automation. You need to learn to feed the robot and take away parts faster, which actually may lead to more hires.

5. Engineering and design. No matter what type of automation system is implemented, the welding torch still requires access to the weld location. As good as robotic arms are, they are more bulky and have not yet reached the dexterity of the human arm and hand. Also, the design and engineering of the system will determine the positioning of the workpiece during welding and determine how much of the product can be robotically welded and how much must be left to hand welding.

6. Culture change. Last, the company’s culture must change and, management and supervisors need to manage not only the production equipment, but also the human assets of the shop. Having a clear understanding of the pulse of the shop is important.

If questions arise about job loss due to the implementation of automation in the shop, focus on the new opportunities for training and education and the benefits to safety, the environment, and career advancement.

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