Shifting Paradigms: Automation Comes to Wheel Balancing
With ABB robots and a new material from 3M, Esys Automation is revolutionizing the important-but-often-ignored world of wheel balancing.
In tire and wheel assembly there aren't a lot of game-changing advances you can point to that have completely altered the paradigm for how wheels get fastened to cars and trucks at the factory.
"Indeed, wheel balancing isn't something that gets a lot of publicity," jokes 3M's Scott Taylor, "but when it does you can be sure it's for a good reason."
Taylor, the Automotive Market Technology Manager for 3M, has reason to be celebrating: it's 3M's new wheel balancing material that finally enabled the full automation of something known for being a notoriously costly bottleneck in the automotive industry. Along with Esys Automation, the two companies have developed an incredibly simple, fast, and compact system that relies on robots such as ABB's IRB 140 to reduce wheel balancing cycle times drastically while increasing ride quality for the end consumer to previously unheard-of levels. (Shown right, the ABB robot IRB 140 applying the new 3M balancing material to the wheel rim.) ?
"3M's product was really the enabler for us," says Chris Marcus, CEO of Esys, the company responsible for developing the AutoW8t wheel balancing system. "Their revolutionary metal-impregnated polymer tape gave us the ability to bulk store balancing material and feed it to a line. Once we saw the product and the idea was pitched to us from 3M, AutoW8t was an obvious solution."
Traditional clip-on weights are pounded onto the flange of the wheel by hand, introducing cracks and chips that can easily lead to corrosion. The process is painfully slow - at least in automotive manufacturing terms - and has always been one of the biggest bottlenecks in the assembly plant. Automation of this process has long been considered one of the "Holy Grails" of bottleneck reductions.
Benefits of AutoW8t Robotic Wheel Balancing System
Better for the environment: lead-free, corrosion-free, reduced waste, recyclable Improved worker safety: no risk from repetitive hammering or deflection injuries Increased speed: complete elimination of traditional wheel assembly bottleneck Reduced cost: smaller footprint, elimination of duplicated stations, smaller inventory, reduced waste Increased performance: incredible ride quality, sleeker look
Robot-Based Automation Solves the Conundrum
"The industry has been trying to automate wheel balancing for 15 to 20 years," says Taylor. "In some cases they were getting close, but the problem lay in the way the traditional wheel balancing materials were coming in. Traditional weights were supplied in discrete increments made from materials that couldn't be cut. 3M's new material gave them a product that could be easily cut and not have any issues with corrosion."
In addition, with the ban on lead weights the industry has moved to steel, which isn't as malleable as the old weights. While better for the environment, the trickier-to-handle steel weights have caused the car makers and suppliers to inventory a tremendous amount of parts to conform to the large variety of weights and wheel dimensions required. Even then the wheels can only be balanced to within one quarter ounce - far from being a true balance. In addition, as the manufacturers move toward a sleek, flangeless look, the question of where to clip on the weights becomes a conundrum.?
With the AutoW8t robotic system all of these issues in the traditional wheel balancing process have been dealt with succinctly. Using compact 181 lb rolls of the conformable polymer composite, corrosion-free, adhesive balancing tape, the AutoW8t system feeds the material from a central storage location to a small 3 x 4 ft cell.
"In the manufacturing world that kind of footprint is tiny," says Marcus. "We're able take this little system and slide it in right behind the balancer in an existing plant without much modification. In addition, our feed system allows the 3M material to be loaded in a safe location in the aisle and then fed overhead to the balancing cell to avoid any need for workers to enter potentially hazardous and space-limited areas."
Balancing Weights Placed with Surgical Precision
While the feed system and revolutionary material are news in their own right, it's inside this compact cell that the true automation magic happens. The polymer tape is fed to a specialized magnetic gripper placed on the end of an ABB IRB 140 robot. The gripper receives two precision cut strips of material and then, using calculations performed by the balancer at the upstream balancing station, places the adhesive-backed weight strips with surgical precision on the interior rim of the wheel. The result is increased quality, reduced waste, and much lower costs - not to mention drastically increased throughput and a much sleeker look. (The AutoW8t cell, right, has a very small footprint.)
"When we first started using 3M's material we created a semi-automated system without robots," says Marcus, adding that they quickly realized the biggest benefits would be from a fully automated system using a robot applicator. "An average operator in the semi-automated system might be able to apply one weight in 15 to 20 seconds, while the robotic applicator can apply two weights in 10 seconds."
Cycle Time Improvements Result in PACE Award
In an industry that jumps when it hears improvements on the order of 1 to 3%, the ability to reduce cycle times by more than 65% is an amazing leap forward. In fact, the incredible accomplishment earned both 3M and Esys one of the automotive industry's most prestigious honors: a 2012 PACE Award.
"It's rare in our industry to get recognized for anything, so we certainly didn't expect a PACE Award," says Marcus. "AutoW8t is a dramatic change to the paradigm of tire and wheel assembly. Now that a few major manufacturers have implemented it, what we've found is that all of them are moving quickly to do trials and tests and get the equipment in their plants. I see our AutoW8t system as the way all wheel balancing will ultimately be done by every manufacturer if they want to remain competitive."
