Managing a truss with multiple pieces can affect productivity. For example, maintaining compliance with ANSI/TPI 1 Chapter 3 requirements for nearly thirty pieces can be challenging. To improve cycle time while preserving quality, using sub-components may be a practical solution.
Most likely, some truss builders have objected to separating projects into sub-components. They may argue that it increases labor (and therefore cost), but does it? When you have a complicated build, it may be more efficient to break it down into smaller steps that can be more clear and more easily managed. The quality of the end result will likely be improved too. [For all images, See PDF or View in Full Issue.]
A Closer Look at the Details
As a real-world example, let’s consider the following attic truss. Taking a closer look at the design, it can be argued that panel points 14 to 25 should be constructed on a separate assembly table that is concentrating on just the floor section of the attic area. Doing this will make it a little easier to keep gaps out of the assembly, thereby producing a higher-quality end result.
Here is another great example. It’s difficult to even read and interpret the drawing, so a sub-assembly that is adjustable by slight trimming might be a better solution.
Without the availability of a separate press, the assembly shown is laid out on the regular assembly table. Note that most joints are stapled to hold joints together. The component manufacturer is also pre-back-plating joint 26, which is a critical joint to aid in accuracy.
Then, the sub-assembly is easily inserted into the larger assembly.
The Bottom Line
Complex components can be simplified by breaking them into smaller pieces, which can enhance quality and improve productivity. This approach also prevents un-plated connections. Additionally, controlling pushing and slipping when the finish roller moves the design left and right during gantry cycling is another advantage that is gained when using sub-components.
Rather than seeing sub-components as extra work and extra cost, they can be easier for truss builders to manage and execute properly. If you’re not already, you too should consider using sub-components in your assembly process.
An ANSI/TPI 1 3rd Party Quality Assurance Authorized Agent covering the Southeastern United States, Glenn Traylor is an independent consultant with almost four decades of experience in the structural building components industry. Glenn serves as a trainer-evaluator-auditor covering sales, design, PM, QA, customer service, and production elements of the truss industry. He also provides project management specifically pertaining to structural building components, including on-site inspections and ANSI/TPI 1 compliance assessments. Glenn provides new plant and retrofit designs, equipment evaluations, ROI, capacity analysis, and CPM analysis.