Metal fabrication and the solid model

A microcosm of the evolution of modern metal fabrication has unfolded outside Chicago since November of last year. A dumbwaiter manufacturer having roots going back to the 1880s, Matot’s Bellwood, Ill., factory, with its unassuming brick façade, houses a typical high-product-mix operation. Some dumbwaiters are floor-loading, some are loaded at waist-level, and all are customized for the building. There’s a common template for product families, but options abound. One dumbwaiter doesn’t entirely resemble the next. It’s engineered to order.


Up until last year, shop workers used traditional techniques. Dumbwaiter design information was printed out or written onto forms, and workers used traditional equipment like notchers and shears. Now, the shop floor’s 11 workers fabricate what’s needed for the week, no more and no less. But starting in November of last year, things began to change. They still judge a certain part’s manufacturability, but instead of just making it work, they talk with company engineers about the problem and as if the model can be changed.  In other words, it’s all about the solid model.

Traditionally that information has resided inside the minds of skilled technicians on the floor. Now, more manufacturing information than ever resides inside the solid model database. “It has become the central repository of all the information that drives our business,” said Jon Lane, acting vice president of operations. “You get your routing off of there, you get your bill of materials off of there, and you can get your process off of there. It has become the foundation.”

I spoke with a fabricator last week, Sam Kusack at Kammetal Inc., who graduated in 2001, launched a welding shop in Brooklyn , saw the Twin Towers fall several months later, and this year got a chance to finish fabricating the top 50 feet of metal cladding for the new World Trade Center.

That’s not a bad accomplishment after a dozen years in business. Kusack started with just a welding machine and a chop saw--and, unlike in previous generations, he also knew 3-D CAD software from the very beginning.

We’re now in a data-driven manufacturing world, even at the smallest companies. The days of shop floor workers “making it work” at the press brake or welding station isn’t as prevalent now. With software talking directly to machines, front-office staff knows what tools are available, simulate the bend sequence, taking grain direction and all the sheet metal idiosyncrasies into account--all before cutting a blank. This really has changed the nature of the job. As Lane explained, the company now adapts the model to the manufacturing process--not vice versa.

When people outside manufacturing talk of automation, they envision space-age robotic lines. But high product mixes and low volumes usually don’t make such equipment practical. What has driven efficiency--reducing WIP and shortening overall manufacturing time--is the software that tackles problems before a job becomes a physical part or batch on the floor.

At Matot, Lane recalled how employees used to trim a blank here, notch a bit there. Today, if a manufacturability issue arises, they ask if the model can be changed. As Lane aptly put it, “We design around our process. Our process isn’t structured around our design.”