How to check if motor is burnt out? - RC Groups
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Sep 13, 2003, 09:24 AM
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How to check if motor is burnt out?

I recently got a feda dragonfly. It worked fine during the first flight (I was really enjoying it too! ). But on the second time, the main motor does not seem to start up.

Does anyone know of a simple way to check if it is the motor that has burnt out? (do they burn out so easily just after one flight?!)
Are there any visible indications on a burnt out motor that I can check for?

I've tried swapping the tail motor and the main motor around (where you plug it into the mixer) and the tail motor still works when I give the corresponding inputs on the transmitter, but the main motor doesn't work in either slots. Does this mean the mixer is still ok, and it is just the main motor is broken?

Thanks for any help,
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Sep 13, 2003, 12:14 PM
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yeah that happened to me too
i had 3 minutes of flight straight after getting home from buying it and half way in my spool-up, throttle chopped. tested and it was not esc fault. went back to my LHS and they said they were willing to give me another motor but they will not accomodate another similar occasion as there 'was no gaurantee on these product'. might be the factory QC
Sep 14, 2003, 03:00 AM
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Supersix's Avatar
dont hook it up to heli if u r suspect as this can cause a short in the motor and fry your mixing board. i know two people that this happened to (the original motors arent worth jack #@$%) if it dont spin i would say it is rat @#$% i bet if u take of the end of the motor one brush will be missing
Sep 14, 2003, 07:53 AM
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Thanks for the tips guys.
Looks like I need to look into buying a more reliable motor for it.
Sep 20, 2003, 05:58 AM
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Ok, I took the motor out and had a play around with it and I've found out that the motor is still fine. It's just one of the capacitors that's connected to the shell casing is busted.

Does anyone have any information on what these capacitors are called (and what they are for) and if they are easily purchasable from electronics stores?
(There's a number 473 written on it and the capacitor is light brown in color).

Sep 20, 2003, 11:29 PM
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Supersix's Avatar
yes i got the caapacitor from dick smiths the part number is
R 2360
cap cer 50v y5v 5mm ls 0.1 uF (that what invoice says on it)
they were 30c each
Sep 21, 2003, 12:32 AM
"Simplify, then add lightness"
The 473 on the cap means 0.047uF, but the 0.1uF cap that Supersix mentioned will work fine. However, a broken cap will not keep the motor from working, unless the broken ends are shorting the two motor wires together. The caps are only there to keep the motor from interfering with the receiver. The motor should still run without any caps at all.


Ps. I was curious about dick smiths, so I looked up their web site. It looks like an interesting store. Their part number for the 0.047uF is R2007. For those of us in the US, the radio shack part number is 272-134.
Last edited by jeffs555; Sep 21, 2003 at 12:46 AM.
Sep 21, 2003, 07:12 PM
Registered User
Thanks all! I got some capacitors from Dick Smiths on the weekend and my bird is up in the air again!