Component manufacturers learned one very painful floor truss lesson in the 1970s that needed to be remedied in the 1980s – nightmare repairs can result from plates not being fully embedded. That predicament usually resulted from insufficient tonnage to fully press the larger plates found on double chords, near off-center chases, or on special end details. Suppliers rectified this with an array of solutions, one of which broke the mold and another set the standard for the next 40 years.
Nearly all new machines in the 1980s were roller gantries, based on the 40-foot-long “flip and back plate” models of the 1970s, with one unique exception, the Structur-Span extruder machine conceived by Jim Adams, a decorated WWII pilot and TPI founder. He created the J.D. Adams Company in the 1950s, a full-service plate and machinery company that was later sold to Truswal. The Structur-Span could handle the largest and heaviest gauge truss plates, and was very labor efficient, as attested by Don Hershey and Carol Shoffner. Though it has been supplanted by other machines, the out-of-the-box design of the Structur-Span may be the best choice for floor depths greater than 24 inches and on spans up to 32 feet. [For all photos, See PDF or View in Full Issue.]
Alpine debuted its second generation floor machine, the Speed-Roll, as part of its big equipment splash at the first dedicated industry equipment show, the 1980 BCMC in Louisville. The Speed-Roll replaced Alpine’s prior offering, the System 42 Fabricator, that had a light duty vertical press head without sufficient power to seat larger plates. The very name of the new machine announced its superiority to the start-and-stop traverse of the Fabricator, or any vertical press machine. With rollers on the top and the bottom of the kick-leg table, and a larger motor than the Clary, plate embedment was much improved. And being exhibited adjacent to the venerable Roll-A-Master roof machine gave the Speed-Roll an extra degree of credibility at BCMC. At the same time, Alpine implicitly signaled its full embrace of roller technology and their intent on becoming a full-fledged machinery supplier.
Tee-Lok introduced its own version of a kick-leg machine, with air cylinders in the center of the table, each protected by adjacent skate rollers to preclude damage when a truss is flipped to the opposite side. Tee-Lok’s 24-inch rollers and powertrain provided better embedment than the 18-inch rollers on Alpine’s or Clary’s floor machines. However, on all machines with floating tables like these three, plating was compromised if the kick legs were damaged or if the floor was not level. In addition, over many years of use, and thousands of pressing cycles, these ½-inch thick tables are subject to bowing due to metal fatigue, which also negatively affects plate embedment.
In contrast to the equipment made by plate suppliers, a hulking floor machine arrived in 1980 from an independent that acquired a nick-name apropos for both the machine and the inventor. This behemoth, dubbed the Fatman and built by Ronnie Wright, towered over all the other roller gantry floor machines, and set a standard still in force today. The Fatman rode on the table itself, eliminating the risk posed by poorly maintained kick legs, or an uneven floor.
With this machine, Ronnie demonstrated both the welding prowess he had gained in his dad’s shop and that he honed in Clary’s plant building component saws. He left Clary in 1968 to start his own business, Production Equipment and Engineering, and built roller equipment for Alpine. In the late 1970s, he began working on a floor machine that would correct the shortcomings of existing machines.
The Fatman led the competition with the following features:
- Better plate embedment because the gantry head is fixed vertically between an elastic pad on top of a tube-steel section welded to the table and a V-shaped bearing angle welded to the bottom of the support structure.
- More accurate camber by providing separate adjustments at each jig.
- Easier flipping and ejection due to pop-up lifters on both infeed and outfeed sides of the table.
- Capability for end ejection via exit rollers in the table.
- Expandability because the table has intermediate floor supports, additional sections can be readily added on in the truss plant.
- Operator riding platform.
Hydro-Air also upped its game by doubling the plate pressing power of its Beaver floor machine from 40 to 80 tons. However, by the early 1990s, this would be of little consequence. Going forward the table-riding roller gantry machines would the preferred way for CMs to exploit the three fundamental advantages of floor trusses – longer spans, open webs, and easier installation.
Next Month:
The Last Round of Floor Machines
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