# how to measure the motor power????

#### yevgeny

##### Member
hello guys,
hope you r all doing well.
well i have some sort of a strange question...
am doing my own motor and my own solid fuel.....and after that i want to simulate it on a simulator for alt. prediction and so on. but the problem here is that i do not know how much power and impulse is coming out of of this thing????
Is there a way or a thing that i can do in order to know how much power is getting out, either a guage thing or a theoritical calculator that take the ingrdients of the fuel. or any kind of any indicator??????????
thanx guys for help.

#### n3tjm

##### Papa Elf
Simple way, mount a motor on a scale and use a camcorder to record the firing. Find out the frame rate of your camcorder, and go through the video one frame at a time, and write the measurement on the scale (thrust) at that moment. The frame rate equales the samples. So if the camcorder records at 30 frames per second, you will record 30 data points a second. Then once you get all the data points, plot a line graph. This is your time/thrust chart. Calculate the area under the chart to get your total impulse.

If you have a computer, and a few bucks to spend, you can buy a load coil, which measures weight, and build a test stand. There are sites on the net that tell you how to do that.

#### yevgeny

##### Member
really thanx n3tjm
i got the idea and i will try to find our my cam corder frame rate ???!!
but in the mean while what if i have a computer and willing to spend some money
can you guide me how to build this stand or tell me wher to find ppl who have done a simple stand for thrust measurement ........
thanx really man for the advice )
have a nice day

#### bobkrech

##### Well-Known Member
"Simple way, mount a motor on a scale and use a camcorder to record the firing. Find out the frame rate of your camcorder, and go through the video one frame at a time, and write the measurement on the scale (thrust) at that moment. The frame rate equales the samples. So if the camcorder records at 30 frames per second, you will record 30 data points a second. Then once you get all the data points, plot a line graph. This is your time/thrust chart. Calculate the area under the chart to get your total impulse."

Doug

This works fine in theory, however most digital scales have a 1 or 2 Hz sample rate so you won't get enough data points to get the curve.

Bob Krech

#### n3tjm

##### Papa Elf
Actually, I was thinking of an analog scale... There is one at work that would be perfect for smaller motors...

#### Rocketjunkie

Originally posted by edwardw
Camcorder frame rates are usualy 1/29.95th of a second...I call it 1/30th.

1/30 second for NTSC (USA), 1/25 second for PAL (Europe).

Replies
8
Views
985
Replies
21
Views
704
Replies
18
Views
647
Replies
23
Views
2K
Replies
138
Views
4K