Page 18 - MetalForming July 2012

Resistance- Welding Control
...means never having to change welding schedules as sheet thickness, or even the number of sheets being welded, changes. The control also automatically compensates for the presence of corrosion and adhesive, as well as electrode wear.
BY BRAD F. KUVIN, EDITOR
Full-service metal stamper PTM Corp. has been on a “wild ride” the last few years, according to the company’s sales and marketing director Mark Cross. Specializing in design assistance, prototyping, four- slide and progressive-die design and build, as well as short- and long-term production, PTM has been on a mis- sion to become a turnkey project man- ager. Some 70 percent of the firm’s busi- ness falls under the heading of automotive, the rest for customers in the aerospace, medical and other industries.
Cross explains how the firm’s most recent capital investment—an adap- tive resistance-spot-welding (RSW ) sys- tem—fits into its expanding core com- petency of prototyping and low-volume short-run production:
“Many of our customers, particu- larly in automotive, request that we
An operator at the PTM advanced engi- neering center takes a resistance-welding gun in hand to work his way around a fix- tured wheel-housing assembly comprising 18 stamped parts, some of which are galva- nized. Thanks to adaptive process control, he need not worry about material stackup, the presence of adhesive in the joints or other variables. The control automatically senses resistance during every weld and adjusts the weld schedule accordingly, generating the specified amount of heat to ensure good-quality welds—all 275 of them.
provide documentation that illustrates all of the steps we take to develop opti- mal weld schedules during prototype development,” Cross says. “The new adaptive control system streamlines the documentation process, by reduc- ing and in some cases eliminating the need to develop and track new weld schedules for every combination of workpiece material and joint thick- ness. That, in turn, dramatically reduces the amount of documentation we need to develop, and the time spent on maintaining weld schedules. In the end we realize a sizable savings in labor,
which we can pass along directly to our customers.”
The adaptive weld-control system Cross speaks of is the MFDC 560, sup- plied by Aro Welding Technologies Group, a French company with U.S. headquarters in Chesterfield Township,
16 MetalForming/July 2012
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