Warren, MI —Although many of its competitors have incorporated linear motors into new machine tool designs, engineers at Lamb Technicon say that the technology has yet to offer the appropriate price/performance trade-off to justify its use. "We're within a few years of making the leap to linear motors, but right now we feel that traditional ball screws still do the job," says Ed Wallerman, R & D project manager.
Engineers who design machine tools and other high-performance equipment favor linear motors because of their super-fast acceleration speeds, which allows them to boost machine throughput. Under controlled circumstances, it's possible to get up to 3g's out of a linear motor, while ball screws max out at about 1g.
Nonetheless, ball screws continue to maintain the edge with companies like Lamb Technicon, who say that the cost difference between the two technologies makes it difficult to justify linear motors today—whatever the performance gains. In one sense, they're right: Though linear motor sales are taking off, the relatively high cost—about $1,500 per axis as compared to about half that amount for ball screws—has been one impediment to faster growth.
But with expectations that costs will come down, due to increased volumes and more stringent performance requirements, researchers at Lamb Technicon are continuing to evaluate linear motors. In parallel efforts, they are also devising alternative ways to increase machine throughput with new innovations such as its dual spindle technology. "We're essentially doubling the throughput without changing the speed," explains Wallerman.