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Double scissor lift

  1. Dec 29, 2012 #1
    Hello everybody ,
    i'm new here .. so i hope that you help me in this problem ..
    i have to make an analysis for a double scissor lift , it has to lift 4000 kg , for a length of 2 meter ,,
    i have to calculate fatigues ,buckling ,deflection , welding ,screws and the material selected !! so any body can help !!
  2. jcsd
  3. Dec 29, 2012 #2


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    Gold Member

    There is a scissor lift freight elevator I go by at times and when operating it just seems fascinating.

    Since you have 2 members as a unit ( 8 members altogether i guess ) that straighten out as the lift rises,you would want the members to be more than 1 meter each in length, otherwise the thing would topple over when fully extended. So you could start by picking a particlular member length and with the use of FBD, check the forces on members at specific heights of the lift, and stabiliy at maximum height with a 4000 kg load.

    If that is OK, then you have to pick a material, cross-section and size of member, calculate stresses and deflections, etc. I not acceptable then you may have to do several iterations in choosing lengths, cross-section, and size of member.

    The iteration thing no doubt threw you off, as there is not one single simple equation to plug in some numbers and voila - out pops the answer.
    have fun!!
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