Hello everyone, I have been trying to do some hand calc for a scissor lift mechanism. There is a post on the forum (http://www.mechanicaldesignforum.com/showthread.php?700-Scissor-Lift-calculation) describing the calc for a on stage mechanism which I agree with and found the same result separately. It is also refering to this webpage (http://www.engineersedge.com/mechanics_machines/scissor-lift.htm, which has been corrected since). This website also states that for a n-level sicssorlifts stacked up, the required force is multiply by n. Somehow I can believe that is right (the base of a one stage sicssor has to travel twice the distance of a two stage scissor with hlaf the arm length); but I can not put a freebody diagram on it! Can somehow explain to me with a free body diagram in the static case why that is? Thanks a lot in advance.