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How to calculate torque for a motor?

  1. Nov 14, 2011 #1
    Hi all,

    Just wondering how to work out what torque motor we need to get to lift a certain (as yet undetermined) weight.
    Is there a formula to work out what torque we need once we know the weight?

    Thanks in advance
  2. jcsd
  3. Nov 14, 2011 #2
    It depends on the diameter of the drum that you are winding your cable onto. If you had a weight of 1 Kg (1 N) and a dia of 1 meter youd need a minimum torque of 1NM.
  4. Nov 14, 2011 #3
    Torque is Force X Displacement. So you could calculate your force using newtons equations of motion to get your missing variable like velocity if needed. Or you could just assume a height and multiply by gravity. that will give you force. This however is also assuming a 0 angle in the lift.
  5. Nov 21, 2011 #4
    If you want to calculate torque which occurs in shafts, you have to use this formula;
    P=2* (pi) * f *T
    T is torque (Newton*meter)
    P is power (Watt)
    pi = 3,1415...
    f is frequency of rotation (1/s = Hz)
    sometimes you can find revolution as rpm. So you have to change rpm to frequency.
    (1 Hz = 60 rpm)
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