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Understanding specs on trussing

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  • Understanding specs on trussing

    This question seems to answer itself, but if there's one thing I've learned on this forum, "It depends" seems to be a common answer. I'm looking at the specs of a 5' section of square trussing, They list the CPL (center point load) max as a bit over 2000lbs. So I take that to mean I can suspend 350-400lbs of speakers from the center point with no problem correct?

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  • #2

    Would it not be dependant on what is holding up the truss?

    I am not an expert but if you have a stand that says 250lbs max on each side that would change things.


    • #3

      The center point load is the specification for how much point load the truss itself can safely support provided it's properly supported on each end in a simple beam condition. This considers both bending moment, as well as sheer at the ends. This number changes with length for the same style of truss, and at some length the truss will be able to support only it's own weight and nothing more. At this point the truss is useless.

      Note that there is also a distributed load specification and from the two, we can calculate a variety of point loads distributed. This is what structural engineers do at large shows, evaluating all of the elements for safety and most places now require load cells for multiple point, staticly indeterminate loads, as the loads can vary with position and load on other points.

      Former product development engineer: Genz Benz, a KMC Music/FMIC/JAM Industries Company, continuing factory level product support and service for Genz Benz

      Currently product development engineer: Mesa Boogie