Sixty Years of Machines, Part XXVII: Optimization Redefined

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Issue #14271 - February 2022 | Page #10
By Joe Kannapell

A new truss plant owner faced a daunting challenge: local home builders wouldn’t use trusses and apartment builders were driving tough bargains. The owner’s partner, Charlie Barns, 250 miles north in Dallas, couldn’t have understood since he was cranking out hundreds of trusses a day. Yet the owner, Dick Rotto at Trussway Houston, had risked all he had on this startup, and had to figure out how to survive on low margined work. Fortunately, Rotto brought in some key people to help him get there.

Rotto’s truss designer, Mark Rolf, suggested shifting truss webs slightly to be able to cut them out of shorter stock – thus optimizing truss configurations. However, this made it harder to get cutting details since Gary Sweatt’s Cutting Manuals only covered standards. Rolf could run the trusses through the Online Data teletype, but, in 1972, this racked too much timesharing expense, long before this became a standard feature in truss programs.

Dick Rotto’s other key hire, John Wiggs, figured out how to become even more competitive. Wiggs prided himself in looking beyond what the plans specified and recommending more cost-effective alternatives. For example, he’d lower roof pitches slightly to preclude piggybacks, replace expensive beams with truss girders, or stretch the normal 24” spacing to eliminate trusses. It didn’t take long for this building design optimization to become a widespread industry practice.

Downstream from these design practices were the gains that resulted from optimizing saw batches. At Heart Truss & Engineering, this had always been a key driver of efficiency. Heart’s Bob LePoire recognized the value of combining like pieces to save saw time, and challenged one of his designers, Ken Dugopolski, to write a program to do so. The result was the Shelter Engineering Program of the mid-1980s (not to be confused with the Forest Products Industries [FPI] program offered by Shelter Systems of New Jersey). The Shelter program read the engineering output files and created optimal batches, but it also relabeled truss members as it did so. The beneficial result was that each unique piece type had a unique label. For example, if W6 on truss T2 was identical to W1 on truss T1, W6 would be relabeled W1 on all paperwork. Heart surely advanced the art of optimizing batches, a practice that would gain new significance with linear saws.

For the next decade, while the above practices became commonplace, few other developments occurred until 1999, when Jim Urmson’s linear saw hit the market. Urmson and his customers realized that optimization was different with the TCT. They now needed to control and optimize the arrangement of pieces within the confines of a given lumber length. Urmson provided one way, never offered before, for his TCT to “look ahead” on the cutting list and pull together pieces that would fill out the remainder of a board. But, in order to determine the optimal arrangement of these pieces, some of them needed to be reoriented. In the example shown, if piece 10b is flipped left-to-right, its angle-cut will match 10a’s, and if 10e is flipped upside down its angle cut will match 10c’s – an endlessly iterative process requiring a sophisticated computer program to identify the optimal solution. [For images, See PDF or View in Full Issue.]

The potential of such a program did not go unnoticed by Dave McAdoo, Alpine’s Director of Engineering. After several visits to Alpine’s accounts using TCTs, he realized that a linear saw could actually make good on the infamous new-hire con, “go get the board stretcher.” While McAdoo planned to exploit that feature to the max, he was too busy getting the ALS from the 2002 BCMC Show floor to a Beta site. After the saw was ready for prime time, he’d turn his attention to developing software that could combine the above pieces as effectively as is shown here, redefining the potential of optimization.

Next Month:

Proving the ALS

You're reading an article from the February 2022 issue.

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