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does anyone know???

Old 01-05-2009, 01:11 PM
  #1  
anhourlater
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g'day all,im a new member from OZ and would like to know the formuka for working out wattage if you havent got the specks.also has anyone beleive the specks on aeolian out runners?i just got a 4260 from them and i cant see it being 1890w!its good to see alot of fello sparkies out their!
BRUSHLESS RULES THE SKYS
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Old 01-05-2009, 01:20 PM
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gfdengine204
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The mathematical formula to calculate watts is:

W = V * A

Where W = Watts, V = Volts, and A = Amps.
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Old 01-05-2009, 01:27 PM
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anhourlater
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thanks for that.so if i multiply amps by voltage will that give me the true answer of what the watts should be?
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Old 01-05-2009, 01:42 PM
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ron_van_sommeren
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That will give you the power consumed by the motor:
http://en.wikipedia.org/wiki/Power_(...ectrical_power

Can you tell us what and how you are trying to calculate power? Using which numbers?

http://www.wattflyer.com/forums/forumdisplay.php?f=3
-> Magic numbers for modelers...
and
-> Everything You Wanted To Know About Electric Powered Flight

Next time a better title?

Gelukkig Nieuw Jaar Ron
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Old 01-05-2009, 01:49 PM
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anhourlater
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i have a couple of motors that i only know the kv of.i would like to try and work out the wattage of the moyor if possible so i know im not going to cook it by putting on to large a prop.thanks
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Old 01-05-2009, 02:57 PM
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slipstick
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No sorry. It's not possible to work out the wattage just from the Kv. OTOH if you already have the motors you must also know the size and weight of them and those will give you a better idea of the power handling (watts) than the Kv will. The same physical size of motor can usually handle roughly the same power whatever Kv it's wound for.

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Old 01-06-2009, 04:49 AM
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anhourlater
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thanks slapstick.heres what i can tell you about this motor.its a 3732 in dia.constant amps is 50 with a 70 amp max.take up to 24v has 13 poles.560kv.that about all i can work out with it.motor feels heavy in hand.thanks all
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Old 01-06-2009, 10:31 AM
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slipstick
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Errrm....did you miss post #2, the answer to your original question ? You already have all the data you need. If it takes 24V and 50A/70A max then those are the most useful numbers you can have.

In power terms that's 24V x50A = 1200 Watts. 24V x70A maximum = 1680 watts (but I never trust absolute maximum ratings). If that power rating is right I'd expect it to weigh roughly 400-500g / 14-17oz.

BTW what does "3732 in dia." mean ? I don't think you mean 3732 inches diameter (i.e. 300+ feet). That would be rather large .

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Old 01-06-2009, 10:38 AM
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anhourlater
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thanks slapstick now i understand it the way you put it.i forgot that i was on a american forum and down here in oz we measure in mm not inches.cheers
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Old 01-06-2009, 11:54 AM
  #10  
Buck Rogers
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Originally Posted by slipstick View Post
BTW what does "3732 in dia." mean ? I don't think you mean 3732 inches diameter (i.e. 300+ feet). That would be rather large .

Steve

This notation is used by some manufacturers to describe the stator dimensions - its in millimeters so:

3732 would mean a stator diameter of 37mm and stator length of 32mm.
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Old 01-06-2009, 12:30 PM
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anhourlater
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that the one buck.cheers
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Old 01-06-2009, 07:19 PM
  #12  
Dr Kiwi
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Simply multiplying max amps x max volts is NOT the way to determine max watts.
Is it really capable of 100A constant. http://cgi.ebay.co.uk/Aeolian-500kv-...31210003r16297


Take a look at the Medusa charts: http://www.medusaproducts.com/

Take this example: MR-028-056-2800V2

Max amps = 69A, max volts = 21v Product: 69x21 = 1449W

Actual max watts rating = 500W.

That is a 160g motor - yours weighs a lot more than that (316g), so it is probably capable of >>500W, but I really would be surprised if it could survive the rated 1885W!
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