In the year 2000, a transformation, like none other, gripped our industry. Jim Urmson’s TCT started it by breaking our component-saw-centric paradigm. Then in 2002, Dave McAdoo’s ALS quickened its pace by adding the capability to cut every conceivable truss part. But even before his ALS was underway, McAdoo envisioned a much wider range of innovations, provided that he could prove the linear saw’s viability. And he surely did that at Production Truss in 2003, and, in the process, set a high bar for followers. However, the TCT, the ALS, and their several competitors were just the beginning of a wave of innovation, with software being the critical enabler. [For all images, See PDF or View in Full Issue.]
To minimize waste, linear saw programs cycle through hundreds of possible arrangements of pieces (see “Sixty Years of Machines, Part XXVII: Optimization Redefined”) using an iterative process much more sophisticated than simply sorting by length or angle. From the launch of the TCT in 1999, until Dave McAdoo’s Optimization patent was granted in 2010, the computer algorithms constantly evolved and so did lumber lengths being selected. Early TCT users hand-fed boards, typically picked from a single bunk of 20’ 2x4s. Early ALS users, such as BFS in Jacksonville, achieved better results by picking from 4 different-length bunks positioned near the saw infeed. Later, when lumber decks were added, optimization programs specified the most advantageous lumber lengths and produced pick lists. Once batches were initiated, the saw ran operator-less, and the sawyer became a catcher/stacker. This labor-saving capability enabled linear saws to produce comparable board-feet-per-man-hour to component saws, with much better identification of cut parts.
The ink marking of truss members was a crucial element of the linear saw’s success, eliminating manual marking, expediting truss assembly, and precluding errors. Once these markings began appearing, they quickly were deemed essential, by both build crews and framers. Urmson moved his inker to the infeed side of the cutting chamber and reprogrammed his software to apply the markings before boards were cut. This insured that even the smallest pieces were marked. Later, McAdoo added the girder-ply markings shown here, which are of untold benefit in assuring that these critical structural members are properly plied together.
Another enhancement to marking technology came from Jerry Koskovich’s Assembly Guide System (AGS), which hasn’t been given its due. Plate sizes, plate locations, and useful assembly match-marks were added to enable truss builders to properly place truss parts and plates without reference to truss drawings or projected images. Koskovich included an additional inker on his Miser Saw, which MiTek added to the Blade Saw, to mark the bottom wide face of boards as they entered the cutting chamber. This ensured that markings on pieces that were mirror-images of each other, like Member T1 shown here, always appeared on the “up” face of boards as they would be laid out on the table. Later, this identification was enhanced by adding an “up” arrow so that assemblers knew which end of webs members would intersect with top chords.
As they continued to gain speed and capability, linear saws took on a larger share of the cutting. Comtech in Fayetteville, NC and BFS in Sumter, SC rely almost exclusively on linear saws, as do the 6 Panel Truss plants.
Just as MiTek rolls out its 700th Cyber AT Saw, and is said to be introducing a new saw, are the days of component saws numbered? The most highly automated truss plants seem to confirm that result. Component saws are not found in Randek, Trussmatic, or House of Design robotic systems. But until these highly automated methods become mainstream, the component saw will remain a truss plant staple.
Next Month:
Truss Plate Origins