Considerations to Make Before Investing
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:
- Increased productivity
- Improved weld cosmetics
- Lower materials costs via less overwelding
- Lower energy costs
- Lower manpower costs
- Excellent reliability
- Rapid ROI
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.
Parts Should Be Easy to Weld
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.
Justify Automated Solutions with High Part Volume
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.
Evaluating the Facility
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
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.
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).
Supervision of the Automated Cell
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.
Prior Planning Prevents Poor Performance
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.
Additional Information: Fixed Automation Versus Fully Automated
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.