WHAT YOU MUST KNOW ABOUT ROBOTIC WELDING
By Lloyd Steed
Whether a shop is new to robotic welding or trying to improve an existing operation, understanding these key factors will go a long way in helping to gain a competitive edge and making the most out of the financial investment.
In the job shop and contract manufacturing world, quality and productivity are everything. To remain competitive, these operations must continually look for ways to increase throughput and minimize defects while also keeping their costs low on parts and labor. In many cases, turning to robotic welding is a means to achieve these goals – for both the smaller job shop as well as larger manufacturing facilities.
The decision to implement a robotic weld cell takes a good deal of consideration and planning if the system is to function in the most efficient, productive and profitable manner. And it requires a significant investment. Fortunately, the long-term benefits of a robotic welding operation can be very positive.
For those plants that have already invested in robotic welding but are looking to improve or better understand their operations, or for those considering that initial investment, it is critical to consider and explore these key factors about the technology in order to make the most of the process:
There’s more to the payback on a robotic welding system than just speed. Justifying the cost of a robotic welding cell comes down to the ability to gain (and prove) a return on the investment (ROI). That return typically comes in the form of greater productivity and higher-quality welds that minimize instances of costly and time-consuming rework, but there are also other contributing factors to the ROI in this technology.
For example, robotic welding offers the competitive advantage of lower energy and labor costs and, in many cases, lower material costs due to fewer instances of overwelding, a common and costly occurrence in semi-automatic welding. A weld bead that is 1/8 in larger than necessary can double filler metal costs, but a robot can reduce those costs by only putting down as much material as necessary.
Robotic welding systems also use bulk filler metals (such as 600 lb drums) that can often be purchased at a greater discount.
For those considering that initial investment in robotic welding, understand how to calculate the payback. Assess the current part cycle times and compare those to the potential cycle times of a robot. A trusted robotic welding integrator or OEM can often help with this calculation.
During this process, also assess the possibility of reallocating existing labor to other parts of the welding operation where these individuals can add value to the process. Remember that up to 75 percent of the cost in a semi-automatic welding operation is labor. An opportunity to use that labor elsewhere to increase part production will increase the payback on the investment in robotic welding.
Most shops – particularly smaller ones or those with frequent production changes – seek a payback on the robotic welding investment of no greater than 12 to 15 months. That time frame is entirely possible to achieve with proper up-front planning of the part blueprints, fixturing and general setup of the system. Some plants may be able to justify a longer payback period if they know their production needs will remain relatively static for longer periods of time.
Parts and product flow must be consistent. The output from a robotic welding cell is only as good as the parts fed into it. In order to gain the advantages of these systems, it is critical to have accurate, repeatable part designs. Gaps, poor fit-up or poor joint access will all prevent a robot from completing its job correctly.
The best part designs for an automatic welding application are simple ones that allow the robot to execute the same weld repeatedly. High-volume applications with low-variety parts are especially poised to gain the advantages of robotic welding. Try to avoid part designs that require intricate tooling or clamping to hold the part in place, as both can hinder the efficiency of the robot and also add to the up-front cost of the operation.
That being said, some operations may still be able to gain a good payback on the investment in tooling for slightly more complex parts, but they will need to weigh out the pros and cons of that cost ahead of time.
Be certain to assess the overall welding operation for consistent process flow. Bottlenecks upstream can easily slow down the movement of parts into the robotic work cell and hinder the ability of the system to function to its full capacity. A robot that sits idle costs time and money and may require reconfiguring the operation or setting up a flexible cell that can manage quick tool and fixture changes in order to minimize bottlenecks in the process flow. Don’t forget the importance of having adequate labor resources to supply the robot with parts.
Pages: 1 2
About the Author: Lloyd Steed is a product manager at Tregaskiss, 2570 North Talbot Road, Windsor, Ontario, Canada N0R 1L0, 519-737-3000, Fax: 519-737-1530, www.tregaskiss.com.