To servo or not to servo?
It’s been a long simmering question in the packaging automation business, relating to an emerging new breed of servo-centric packaging machinery known as “Generation 3.”
The Gen3 terminology is typically used to describe a machine that is designed from the ground up to exploit the advantages of closed-loop servo control technology. On a Gen3 machine, traditional mechanical drive shafts and associated cams, sprockets, gears and pulleys are eliminated, and are replaced with servo motors on each of multiple individual axes under integrated electronic control. The machines are typically modular, rely on open architectures, and use integrated motion and logic control.
The result, say Gen3 proponents, are machines that offer numerous advantages, including improved flexibility for faster product changeovers, lower maintenance requirements, improved machine performance and lower total cost of ownership.
What about cost?
But some are quick to point out that Gen3 technology is not appropriate for all applications. A recent report from ARC Advisory Group, Dedham, Mass., noted that while Gen3 has many benefits, the purchase price of a Gen3 machine can be up to 30 percent more than that of a conventional machine.
“Sometimes you can’t justify putting servo technology where a cheaper mechanical or even a manual solution is available,” says David Humphrey, an ARC senior analyst and co-author of the report. “The other big problem is training and technical competence of service personnel,” Humphrey adds. “It’s very easy to put a nice, slick Generation 3 machine into a factory that is so complex that it can’t be serviced by anybody.”
Others, however, note that the training issue is one that packagers will have to deal with. “You know they had to do that when switching from steam engines to diesel-electric locomotives. In order to get the benefits of Gen3 equipment—and the benefits are real—you’re going to have to train,” says Rick Lidington, president of Lidington Technologies LLC, a Charlotte, N.C.-based consultant who works with machine builders on Gen3 designs.
On the issue of price, Lidington says that a true Gen3 machine will cost less than its mechanical and hybrid-mechanical predecessors. One example is the Criterion 2000 cartoner developed by R.K. Jones & Co. Inc, Cincinnati, where Lidington worked previously. That machine came in at a 30 percent price discount compared to the Gen 2 machine it replaced, he points out.
“With a Gen3 machine, you set the goal of halving the number of parts, so it takes at most, half the time to put the machine together, and it also takes half the time to develop it,” says Lidington. These savings are more than enough to offset the higher electrical and control costs associated with a Gen3 machine, he contends. A 30 percent price reduction target for Gen3 equipment is fairly typical, he adds.
Gen3 projections
Currently, about 15 percent of packaging machines being built in North America are true Gen3 designs, Lidington estimates. But he sees that percentage growing rapidly as more end users and machine builders get the Gen3 religion.
At Bosch Rexroth Corp., Hoffman Estates, Ill., which supplies servo technology and controls, Dan Throne agrees. Within five to 10 years, about half of all packaging machines shipped will be Gen3, predicts Throne, who is business manager, food and packaging industry. “Over the next few years, we’re calculating a 10 to 15 percent compound annual growth rate for the use of servos in the packaging industry,” Throne says.
See the story that goes with this sidebar: The Road to Gen3
