Normal Motor Temp for Stock E-Flite Motor

[yamr6]

Hi All,
What is normal operating temp on the stock motor? Or, maybe a better question given the very hot ambient temps is...what temperature would be considered too hot for the stock e-flite motor on the 450X. Apprecate any help!
Thanks!

[mxman311]

I dont know but mine gets so hot you cant even touch it in 4 min easy flying

[Talesin]

Generally the 'burn your fingers' point is around 130F. The time to start worrying about the 440H is 160F. Grab an IR thermometer if you're worried about it, and get an actual temp value.. I've never had mine come down below 115F, which felt hot, and touching it at ~130F worried me a lot until I actually checked with the thermo.

Note that if you haven't yet done the loctite mod, if it's spinning inside the main bearing it WILL come down hotter than if it's turning the inner bearing race as it should.

[yamr6]

Thanks Talesin...appreciate the numbers. I'll check it with the thermo next flight. Have not yet done the loctite mod.

[gdawgs56]

whats the loctite mod?

[Skidpad]

Applying green Loctite (http://www.loctiteproducts.com/p/10/...-Green-290.htm) to the motor shaft where it passes through the lower bearing. The Loctite essentially "glues" the two pieces together, thus preventing the shaft from spinning within the bearing...which chews up the shaft and will eventually lead to failure of the motor.

[mxman311]

Originally Posted by Skidpad

Applying green Loctite (http://www.loctiteproducts.com/p/10/...-Green-290.htm) to the motor shaft where it passes through the lower bearing. The Loctite essentially "glues" the two pieces together, thus preventing the shaft from spinning within the bearing...which chews up the shaft and will eventually lead to failure of the motor.

How do you get loctite in without getting it in the bearings?

[Talesin]

Personally, I'd use Loctite Blue instead of green or red. For one, green is penetrating, meaning more likely to wick into the bearing races, which is bad news. Second, green/red are designed as a permanent bond and are only supposed to be removed with heat (500F), which is likely to damage the motor either way you try to remove it later.

You disassemble the motor, use a toothpick to rub a light coating of blue on the inside of the inner race, reassemble, wait 24 hours for full cure, re-install into heli, set your lash and go fly.

You could paint the shaft instead, but that would be more likely to be scraped off and get into the bearing. I wouldn't go that route.

[ahahn]

The "trick" for the green penetrating locktite is to put a small drop on the end of a toothpick and then touch the toothpick to the motorshaft just above the inner race. You don't want to actually touch the bearing face for obvious reasons.

The wicking action will suck the liquid between the shaft and inner race. Let it cure and go on from there.

Yes it makes it pretty hard to get the motor apart to replace the bearing in the future, but if you heat up the shaft with the tip of a soldering gun, that may make it easier.

The question is how long the bearing will last since you removed this failure mode (shaft slipping in bearing and wearing out the shaft). I'd certainly recommend giving the bearing a bit of oil occasionally, like Scorpion recommends.

[mxman311]

Just pulled motor apart and used toothpick to put tiny amount inside where the motor shaft goes in the motor so i didnt get any in the bearings. I could see a hot spot on shaft so its a good thing i did the mod or motor would be gone soon. Put toothpick about half way in and rubbed green on walls.

Sent from my DROID BIONIC using Tapatalk 2

[jdFin]

Just as another point of reference, my motor comes down barely warm. I can grab it, and have to grab it pretty good to make sure that it's actually a tiny bit warm. The only "hot" I've felt is the motor(s) on my B450 before the bearings blow.

Flights are simple circuits and a few flips; back-to-back flights don't warm it up much more.

[mxman311]

Originally Posted by jdFin

Just as another point of reference, my motor comes down barely warm. I can grab it, and have to grab it pretty good to make sure that it's actually a tiny bit warm. The only "hot" I've felt is the motor(s) on my B450 before the bearings blow.

Flights are simple circuits and a few flips; back-to-back flights don't warm it up much more.

Do you have some sort of nerve damage to your hand and fingers that make it hard for you to feel hot and cold? Kiddint.. Every brushless motor I have ever seen gets pretty warm if not kinda hot after a flight...........

[jdFin]

Originally Posted by mxman311

Do you have some sort of nerve damage to your hand and fingers that make it hard for you to feel hot and cold? Kiddint.. Every brushless motor I have ever seen gets pretty warm if not kinda hot after a flight...........

Ha, you assume I check it with my fingers! I have found that if you lick the motor, it is much easier to gauge how hot it is. Next best is to tuck it behind your ear. picture that....

These subjective things are tough... vibration, heat... maybe there'll be a heat gun at the field next time.