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Old Oct 09, 2015, 10:10 PM
smittyboy is offline
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Symptoms...of a bad motor vs. a bad ESC?

My Dad and I have alot of micros between us, and my Dad is having alot of his micros going bad right now. I am curious…how can you tell if your motor is dying as opposed to the ESC dying? And of course bad batteries add into the equation as well. Can someone tell me the distinctions between the two in regards to symptoms that the plane will exhibit? Bad ESC vs. bad motor…anyone?
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Old Oct 22, 2015, 07:06 PM
rotagen is offline
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I know of no quick way to tell based on what the plane is doing, since all 3 can result in power loss or no power at all.

It's better/easier if you give the symptoms and then let people throw some ideas at you. Having said that, in my experience it is usually the esc that is the problem when considering motor vs esc. If more than one plane is suddenly experiencing problems, what do these planes have in common?
Sounds like it could be a battery or set of batteries you have shared between the planes, unless you have the same motor and/or esc in each plane. Most of my lipos are quite old and some of them are not so great, storing them in zip locks at 4C (beer fridge for me) does extend their life.

If it is a motor or esc problem, in my experience the only way to tell is to swap the motor or esc for a fresh one, so get out the soldering iron, but test a new battery first?
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Old Oct 22, 2015, 09:58 PM
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The single battery cell airplanes have brushes in the motor that get worn out or get burnt. Then the motor loses power and needs the prop to be pushed to start it turning. The brushed motors were designed to spin the vibrator in a phone for a few seconds or to open and close the tray for a CD a few times, not to power a model airplane continuously for 5 minutes per flight. I replaced MANY brushed motors in my model airplanes. Some people say a brushed motor is destroyed if it is running and gets stopped (maybe landing in the grass and flipping over) because then the motor draws a high current and burns the brushes.

The airplanes that are powered by a battery with 2 cells uses a brushless motor that lasts almost forever. This motor and battery also produce a lot more power than the single battery cell ones.

Batteries that are run down until the airplane motor gives its low voltage warning by turning on and off over and over are destroyed if it happens more than a few times. Batteries that are stored fully charged for a month or more (over the winter?) are also destroyed, they should be stored with half of a full charge (3.7V for one cell and 7.4V for two cells).
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