Help! Dragonfly MkII Motor problems!

[BlockerAviation]

This past flight on the Dragonfly MkII bush plane, I had an esc failure on one of my engines. This has been my third failure on this motor/esc set up. Granted this setup is almost three years old but, I've had Rimfire motors that are five years old. The failure seems to have something to do with the esc timing because, the motors make a weird sound before they fail. The first failure was about a month ago when the right motor failed. to fix the issue I had to replace the motor and esc with an Identical combo. The combo that I'm using is the emax 2204 2300kv motors with 20a escs, 3s battery and 3 blade 5045 props found here https://hobbyking.com/en_us/mt2204-brushless-combo-include-esc-600cw-ccw.html. The only prior use of this combo was in a zmr250 that was never wrecked. HELP!

Here's the vid of the second crash. Skip to 1:15

Here are some pics of my setup.

 

[PsyBorg]

Take a look in the holes in the motor base. Look to see if the screws are touching the windings. That fire wall looks thinner then usual and could possibly let stock screws get closer then normal. Could be they are just close enough the windings may wear thru the coating and start leaching signal but not good enough connection to cause a direct short.

Also look at the motor specs page here...
https://emax-usa.com/products/emx-mt-0011-emax-mt2204-2300kv-multirotor-motor

for 3s it says a 5x3 bi blade and you are using a tri blade 5x4.5 so it could be stressing the esc too much. Not saying the motor cant handle that but it is more then recommended.

 

[BlockerAviation]

I thought it was the screw as well but the screw is well away from the windings even without the motor mount.

and I took another look at my props and they have some weird marking that I don't know, but I do know that this setup statically draws 18a at full power.
Here's the prop I'm using, I don't know if the amp draw will be more when the airplane is in the air.

 

[PsyBorg]

5x5x3 means it is a 5 inch propeller diameter, with a 5 inch pitch, and has 3 blades.

That pitch is way to much for a tiny motor like that specially when they call for at best 6x3 and only two blades. Heck, I only fly 5x4.5x3 on my high power quad motors.

 

[BlockerAviation]

Ok, I was given a set of these props a few years ago and I thought I would try them out but I guess that was a mistake. I think I have another esc and the carbon 6x3 props laying around somewhere, I'll give those a try. I'll keep you posted, thanks again!