# Stall Torque question

Hi Everyone!

I am here to see if anyone can help me determine the stall torque of a specific weight in Kg. I am using a 393 motor for my project which specifications say that it has a stall torque of 1.67 n-m, 14.76lbs (6.695kg) I am assuming this is the maximum load that it can move. What I want to do is find out how much torque is used when moving 730g.

I found this http://imgur.com/8jL7BOT equation on wiki and I am not sure if the s2 means speed (in this case RPM).

Am I approaching this in the wrong way or it as simple as entering the correct values into this equation?

Thanks

equation on wiki and I am not sure if the s2 means speed (in this case RPM).

Am I approaching this in the wrong way or it as simple as entering the correct values into this equation?

Thanks

Hey there,

Thanks for posting. I think you are misunderstanding how torque works.
First, watch this video: [What is Torque This video discusses torque in reference to a mousetrap car.

A VEX motor’s stall torque of 1.67 Nm means that the motor will stall when attempting to output a force equal to 1.67 newtons on a 1 meter lever. If you want to know how much torque is required to move 730g you need more information. The equation you referenced is correct.

1 Nm = 1 kg m^2 / s^2

m/s^2 is a acceleration
kg is a mass
F = ma so F = kg m / s^2
Then Torque = Force * Distance
m is a distance
m * kg m /s^2 = kg m^2/s^2 or Nm

You have a mass. However, you also require an acceleration (which is probably gravity) and a distance (which is the lever length). Once you have those things you can solve for the torque.

Cheers, Bryan](“https://www.youtube.com/watch?v=WDq-3Ou0VdU”)

Thanks so much for replying! I have solved the problem!