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Mixing 4" and 6" counterweights

Discussion in 'Scenery, Props, and Rigging' started by usetedaj, Mar 20, 2017.

  1. usetedaj

    usetedaj Member

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    My fly house has a mix of 4" and 6" width counterweights in its inventory. I'd say at least 90% of the weight is 2" high, 4" wide counterweights, maybe half a dozen 1"x4" bricks, and the remainder is 1"x6" bricks. All the pipe weight is 4" wide bricks. Setting aside the question of where the 6" wide bricks came from in the first place, here's the question I have: Is there any reason not to mix 6" wide bricks into the system? By and large, I never use them for anything but doorstops and ballast on wagons, because it doesn't give me a good gut feeling to mix them in with the 4" bricks. Am I off base? Am I worrying about nothing?
     
  2. Ford

    Ford Sr Product Manager, Chauvet Professional

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    If there enough space between your linesets, and there are no other clearance issues, I'm not aware of any reason not to. I would just make sure that the largest bricks are on the bottom.

    That said, I am not an ETCP rigger... so maybe someone a little more qualified might want to jump in here.
     
  3. Van

    Van CBMod CB Mods Premium Member

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    The biggest issue is the space between arbor and having adequate clearance for the bricks. You would need to make sure the arbors can pass each other and any T-Wall braces or side structures when the wider bricks are used.

    The biggest issue is if they fit the arbor length-wise; unless the ears are deep enough that the brick cannot slip past risers on the Arbor, Do not use them.
     
  4. AudJ

    AudJ Active Member

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    Makes me wonder: is there a risk of overloading an arbor on a lineset designed for a certain amount of weight? Or is the total weight limit calculated as a set across all linesets based on structural building design?
     
  5. egilson1

    egilson1 Well-Known Member Premium Member

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    Yes there is a risk of overloading a lineset. Often you see it when people replace their steel counter weights with lead. A properly installed system should have clear signage indicating what the capacity of each arbor and lineset is. That being said, I can tell you that when I do inspections a majority of systems i'm inspecting lack that signage.

    Ethan
     
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  6. Footer

    Footer Senior Team Senior Team Premium Member

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    Its one of the reasons venues should not share weights. Ideally an arbor is designed so when full you are at the max weight for that set. Also ideally you purchase just enough weight to fill all your linesets to the total working capacity of your grid. If more weight is brought in or even worse heavier weight you can be in for a world of hurt.
     
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  7. usetedaj

    usetedaj Member

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    Thanks, folks. These are pretty much the thoughts that ran through my head. My system is wire-guided, and the linesets are all 12" or more apart, so width isn't much of an issue. Indeed, our system has no signage regarding its overall capacity. We're working on that. But I'm not too concerned about overloading it - I rarely have a (non-LX) line with more than 200# of weight on a 4-ft arbor, and even then it'd only be 2 or 3 lines that are even that heavy. In fact, a recent ETCP-certified inspector recommended we get more weight, because we run out far, far before we come close to any arbors reaching capacity. I nearly do run out of weight (minus the 6" bricks) on our production of Cinderella, and it's mostly soft-covered flats. If I were to throw a 6" wide brick on there, it's more of a question of convenience. Say, I'm on deck and realize I'm a brick out of weight, and have a 6" wide brick handy, but all the 4" bricks are on the gallery. As it stands, I just huff it up the spiral stairs and load it up there to avoid mixing sizes. Hence the question!
     
  8. BillConnerFASTC

    BillConnerFASTC Well-Known Member Premium Member

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    You need to find out what the structure was designed to support. That is a limit.

    Most linesets - with at least 5 lines - using standard hardware - will hold 2000-2200 pounds - so that is not a problem - again using standard components. But the building may not be designed to hold X linestes times 2200 pounds. More likely 25 or 50 PSF. Pro stages should be around 100 psf typically - roughly based on 30 PLF on battens 4" on center. Just some broad idea of loads.
     
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