I will try to lift up 25kg (50 pounds)(electrical child car) on a linear actuator and I know that there would be a 30cm long lever.

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But my question is if there will be some lever. I think it won´t because the linear actuator will be in the middle above the load. Or am I wrong and there will be a 20cm or 30cm or 50cm lever?

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Thank you for your advice.

  • $\begingroup$ "I know here would be a 30cm long lever" ... "will there be some lever". Huh? You clearly state there'll be a lever, then you ask if there will be one? If the actuator goes straight up, and the car goes straight up at the same speed as the actuator, then there is no lever action -- the linear actuator is just offset from the car by a beam. $\endgroup$
    – TimWescott
    Mar 28 '19 at 3:03
  • $\begingroup$ Are you asking if there will be a moment created in the arms? Is that why you are concerned about a lever arm? $\endgroup$
    – hazzey
    Mar 28 '19 at 12:32
  • $\begingroup$ @hazzey Yes ... Linear actuator can lift up 100kg on a 1cm lever ... that means on a 30cm lever (picture 1) can lift up 100/30 kg right? ... thats only 3kg ... i am asking if there is the same problem on picture 2 or there is no lever because lin. actuator will be exactly above the load ... Thanks $\endgroup$
    – Jirka
    Mar 28 '19 at 21:31
  • $\begingroup$ You cannot draw that conclusion. But the data you have does not allow anybody to say what it means exactly. There is no information about how the moment is handled thus its only a linear force, if you assume the system is otherwise rigid then both of these situations are the same. Force does not become moment unless theres a hinge, or you account for non rigidity of your levers. $\endgroup$
    – joojaa
    Mar 29 '19 at 6:06

If the actuator is linear, it would be best if you followed the second option where there is no moment with respect to the axis of movement.

However, you would need to make sufficiently rigid the platform that raises the load.


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