How to calculate torque for a motor?

[fkneg12]

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

 

[Jobrag]

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.

 

[rsk2mc]

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.

 

[mohicans]

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)