I was looking for a solution to find the torque of my brushless motors for ages. I could not find any solution. I was chatting with my friend Shane Colton and he told me how to do it.
So these are the steps, for now I don't show why it is correct but it is not that hard to prove just play around with units.
Step 1: KV is usually provided. KV's unit is rpm/Volt
change rpm/Volt to (radian/sec)/Volt
Hint: just multiply by 2Pi/60 or use this.
step 2: inverse the result in step 1. So the unit becomes Volt/(radian/s)
Step 3: Find the current input of the motor.
In case you want to find maximum torque find the max power of the motor in the voltage you are using the motor. Sometimes it is provided by the manufacturer. Then use P=VI to find maximum I.
Step 4: multiply current to what you found in step 2. This answer is torque and the unit is Nm
the equation for the torque would be:
Torque = Step_2_result * Current
