How to find the Thrust coefficient of a Brushless motor?

Im using a potentiometer to control the speed of a motor and i want to figure out the Thrust coefficient of the motor. Meaning, how much more powerful does the motor get when you turn the potentiometer? is there a way to figure this out with software?

Use your multimeter to measure the motor current. Motor torque is proportional to current.

jremington:
Use your multimeter to measure the motor current. Motor torque is proportional to current.

im attaching the motor through an ESC using the Servo library. when i do Servo.write(1)
and measure the current output from the esc, i get fluctuating values from 0.1 to 2. the reading jumps up and down really quickly but motor speed remains the same.

Where are you measuring the current? It should be between the battery/power source and the ESC.

Steve

slipstick:
Where are you measuring the current? It should be between the battery/power source and the ESC.

Steve

alright im not sure im doing this right. I have the red wire of the multi meter on the battery and ground on the esc ground and vice versa. still nothing. values inconsistent.

Let me ask this in a different way, If i do " Servo.write(1)" , how many volts am i sending to the motor? i assume its less than 1volt but how much exactly?

The meter, on current range, should be connected between battery positive and ESC positive. The negative to negative connection is unchanged.

Motors are powered via PWM and ESCs all have their own conversion factors so there's no general way to convert write(1) or any other number into an effective voltage other than 1 is very low and 180 is very high. And anyway it doesn't really help because, as already stated, it is the CURRENT you need to know not the effective voltage.

Steve

I have no idea what you mean by "thrust coefficient" or "more powerful" - perhaps you should clarify this?
powerful suggests power,
but thrust suggests torque.

So what exactly are you trying to measure?