Hey Guys,
I bought an AMMO inrunner brushless 36-40-3900Kv by Electrifly. The recommended input voltage is 14.8 - 18.5 and they suggest a prop between 9x6E and 10x7E. They also suggested an ESC of 45A. So, first I put a 54A THUNDERBIRD from Castle Creations on it and the thing got so hot that it melted the plastic wrap covering the ESC. Then I went out and got a 90A COMMANDER from Scorpion and it too melted. So now I was thinking of trying the Electrifly Silver Series 60A, which is the ESC recommended for this motor. However, Towerhobbies won't have any available until mid to later December. I can't wait that long, plus I'm thinking I won't have any luck with a 60A any way. As a last ditch effort, I'm thinking of getting the PHOENIX 80A from Castle Creations. If that doesn't work, then I'm trashing the motor.

Any advice as to why these ESCs would get so hot that they melt?

Thanks!
Griff

Gosh! I hope there isnt anything wrong with that motor. hmm

I SERIOUSLY doubt it is the ESC. You did not say anything about a gear box. MOST inrunners use/need a gear box to slow the prop down, unless you are using a small prop. If you are using a prop in the recommended range, I would take a LONG HARD LOOK at the motor. Sounds like the motor is pulling excessive amps and that is USUALLY caused by either over propping the motor or a bad motor.

Eh that prop and motor combination is supposed to be run with a gear reduction system. Typically a 3:1 or more...

If you are driving the prop directly NO WONDER you are overheating the ESC!

You are driving far too much current through the motor!

If you run it any longer you'll probably burn out the windings too! ( If you haven't already! ).

Campy and Opjose, you are right! I did mount the motor as a direct drive system. The "Tech Notes" section for the motor at TowerHobbies said it is ideal for both direct drive and gear drive use. I did send an EMAIL to tech support at ELECTRIFLY, so I'll wait to see what their response is before I give up on this motor. I'm not big on using a gear box. I will also try using a much smaller prop and see if it makes any difference.

Thanks for your inputs guys!

At that high of a KV rating you will have to prop it down considerably.... so much so, that it may not be workable for your plane.

Can you put a gear box in your plane to use that motor?

If not you'll need to change it out.

There isn't any workable room for a gear mount. I will probably reconfigure the mount to where I can use an outrunner. I have an E-flite BL10 available.

Im not at all familiar with electric motors
Which would cause more current draw and heat? A large prop or a small prop and how would a gear box help, wouldn’t the motor be turning at the same speed.

Smaller props load the motor less because they produce less drag as they pass through the air. By the time you run a small enough prop on that motr all you will have is lots of prop speed but not pure thrust. By using a gear box you can swing a larger prop at a slower RPM and it will work much more efficintly.

Stick 40

Exactly.

That would be a fine motor for a ducted fan... but to run the larger prop, it would have to have fairly heafty coil wires ( which it does not ) to deal with the large amount of current the PROP causes the motor to draw.

In the "glow world", the prop is almost a secondary consideration....

In the "electric world" the prop determines how much current will be used by the motor.

Prop a motor wrong and you blow your electronics.

i took up electronics for three years, and what i can make out is the motor or the circuit in series
with the motor is sucking up all the current, get hold of a a multi-meter and test.
good luck.

cheers[8D]

Huh?

We do know that it's the motor.... and electric planes the prop determines how much the motor draws.

what motor that recommends a 60 A esc @ 14-18volts only spins a 9X6 or 10X7 prop.

There is some mis-information here.

How long does the motor run before the ESC's burn out?

And.... You are trying to push 10X7 @ that high of an rpm?

WOW.

RedGN,
so what are you saying? The AMMO Motor System Configuration states that this motor with props 9x6 to 10x7 has GEAR RATIO between 5:01 to 6.4:1

This of course is all confusing to me as I'm still a neophyte in the hobby. As I stated before, the 'write up' on TOWERHOBBIES said the motor can be gear driven or mounted as a direct drive.

Anyway, the other day, out of frustration, I ran the motor with my Scorpion Commander and it got so hot, one of the capacitors popped. It scared the crap out of me. It was a fun way to blow a $89 ESC.

Today I lost my SUPER IMPRESS 2. The battery hatch came undone and the battery fell out and without any control, the plane just sailed away.
With no locator in the plane, searching for it would be like looking for a needle in a haystack.

Sorry for the confusion. Direct drive in the brushless motor world means that you are bypassing the gears and have the prop attached to the motor shaft. I know the direct drive also means gears instead of a belt.

If the prop is mounted directly on the motor shaft without any gears, try using a 10X3 or 10X4 prop instead. This will not push as much air and probably say your esc's.

Or buy a gearbox and add it in. This will decrease the RPM at the prop. and increase torque. This method will also save your esc.

You still have not stated which prop you are using. How much the plane weighs, How long it take for the ESC to burn out, or if the airplanes fly at a good speed( enough power for 3d flight or just enough to keep the aircraft airbourne )

We need to know these details.