Smoked brushd 45T

[ReneT]

Hi,

Noob here, just wondering what exactly went wrong.

I burned a Novak 45T today, as soon as i do more than the slightiest throttle the collector glows red and smokes comes out of the motor.

What happened?
The car ran with the motor completeley submerged through some murky water. I've read about brushed motors and figured since water doesn't hurt them it should be fine to run em under water. And if the water wasn't clear it would only increase wear on the collector and brushes.

After that we were making threads through a mud patch, running very slow, so no mud came into the motor. Than smoke came out, with the smell of burnt elecronics. This happened about 15 minutes after the water run. There was a 5 minute break in between.

My guess is the water damaged the motor, the slow running through mud short cirquited the rotor.

Am I wrong and do you have a better hypothesis?
Is running through (non clear) water bad?
Is running for a long time at low throttle bad?

Car is a scx dingo, stock gearing, 2s lipo, novak goat esc, no binding on drive train.

[AR Fabrication]

If you can't hold a finger on the motor can for 5 seconds, it's running too hot and you need to gear down. I will guess you are geared too high. In my Wraith I run about a 5:1 gear ratio, such as an 87 spur and 17 pinion. 87/17=5.12

[alexchen86]

When it comes to motors both brushed and brushless obviously heat is your biggest enemy. Your motor gearing from transmission to differential gears all play a big role in transferring heat. Also keep in mind how much power you are sending the motor from your battery and how continuous.

Easiest way to test gearing is exactly what AR Fabrication said. If you have a infrared heat gun good rule of thumb is 120* for brushed and 160* for brushless motors. Also important is ESC temp which should not go beyond 120* as well but most have thermal shutdown these days. Probably by far the MOST IMPORTANT is your lipo temperature.

LIPOS SHOULD ALWAYS REMAIN COOL TO THE TOUCH OTHERWISE YOU ARE DRAWING TOO MUCH FROM IT THROUGH THE ESC!! Once it gets warm enough it will balloon up even hard packs it will balloon out and crack the case. Keep going and your rig will be a thousand dollar fire ball!

[Twisted Nuts]

I've personally smoked EVERY brushed motor that I have put in water while in a truck. Gearing has not helped me, so I decided to go Sensored brushless and with a little waterproofing have never looked back.

[indiana mudcat]

Driving slow in mud your tires probably added a pound each, if you were geared a little high to begin with that woulda pushed it over the edge.

[ReneT]

Thanks for the feedback guys.

Was rebuilding my car while awaiting a new motor and the drivetrain wasn't as "no binding" as I mentioned in the OP. Too much grease in places it doesn't do any good, combined with shot outer bearrings, high-ish gearing and mud equals smoke.

Learned a bit, next motor should live much longer

[klausdenmark]

Just picked up and IR temperature gauge.

Are those degrees farenheit or celcius?

[Devil Inc]

*F is what you're looking at.