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Making it safe by failing

  1. Oct 6, 2015 #1

    I'm building a filming system that uses two parallel cables to support a mobile camera system.
    The cable supports need to fail in bending to reduce the load on the cables.

    The supports are a mild steel strap, section dimensions 35mm x 5.5mm, distance between cables 200mm.

    Can deflection for such a small structure be calculated by treating it as a simply supported beam with a point load at 100mm?

    The results I have don't seem to be right, 1.3684mm deflection for cable loading of 500kg total load 1000 kg.

    I'll probably have the supports tested in a lab but I want to be in the right ball park. For the system I'm building the maximum loading for some components is 1500kg, I aiming for failure at 300kg, with a safety factor of 5. The cables are rated at 2500kg each.

    Thanks for your help.
  2. jcsd
  3. Oct 6, 2015 #2


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    Gold Member

    With big loads to support and an always risky 'fail safe' design logic you should really consult an engineer who can see what you are doing first hand and give proper advice .
  4. Oct 13, 2015 #3


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    Nidum makes a good point about consulting a trained opinion on this topic.
    I would only like to say that by your descrition alone I have around 6 setups in mind, all different. If you would like an answer a drawing will be more explicit for anyone.
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