Until recently, vertical members have been the bane of all jigging systems, whether they occur on the perimeter or the interior of trusses. And they are found more than ever on apartment and residential designs. Handling these members without human intervention has been the Achilles heel of fully automated systems that endeavor to replace puck-driven jigging. Even so, innovative jigging mechanisms have been developed that allow for unattended operation. [For all images, See PDF or View in Full Issue.]
Auto-Puck Systems: Most jigging systems rely on vertical channels with automated or manual pucks, which have served the industry for thirty years (see my previous article, Sixty Years of Machines, Part IX: Automatic Setup). For instance, Alpine’s patent drawings include a truss with verticals on both ends directly abutting pucks, which would be an exceedingly rare occurrence. As is well understood, however, one of the verticals would have to be manually jigged.
With pre-robotic auto-puck systems, workers are already at the table, and they can affix telescoping end stops to one of the channels. However, with a robotic system, workers must penetrate the light-curtailed area with tools, hardware, and measuring tapes, adding significantly to setup time. And because roofs are becoming flatter, there are many more vertical members to address, especially on large apartment roofs.
Automated Jigging Systems: In comparison, the Trussmatic system overcomes this shortcoming by allowing jigging to be placed where it is most effective, anywhere along the perimeter or the interior of a truss. Its jigging also overcomes the inherent limitation of the pucks themselves, which are only able to work on the narrow face of members. Contrarily, Trussmatic jigging is purpose-built, and can work on the wide faces as well, considerably enhancing its functionality and precision. This is possible because the Trussmatic jigging offsets the truss from the jigging surface, which is a vertical steel wall free of obstructions.
Because of this unique design, jigging has been adapted for three purposes:
EX: Extendable “C” Clamps handle chords, tightly gripping them in their jaws, and holding them at a fixed offset from the webs until all the webs are set in position. Then air cylinders are activated that push the chords inward until they gain tight contact against the webs, while also removing gaps at joints.
WL: Web Locators affix interior members by impaling them with a protruding spike while they are being forcibly set by the robot’s End-of-Arm Tool (EOAT). In addition, these locators are able to secure members that do not intersect with perimeter chord members (see the “internal member” labeled on the right in the diagram).
End Stops extend to tighten end verticals. As shown in the diagram on the left, the stop is fully retracted, while in the diagram on the right it is fully extended, removing the gap between the end vertical and diagonal web.
This truly automated jigging works well because it allows for lumber imperfections. By contrast, in auto-jigging systems, the pucks are set along the theoretical perimeter of the truss and workers often have to force truss parts into the jig or to adjust the jig, which takes extra time and may risk out-of-tolerance results. Poor-quality lumber has always been the principal challenge for automated systems, however, this Trussmatic approach minimizes the disruption it causes.