How hot is too hot?
 

Hello people,

Does anyone know at what temprature a motor will suffer heat damage. I recently installed a temp sensor into my heat sink and can get real time temprature readings. I now need to set a "high temp" warning alarm, so that when the motor gets to a certain temp it will alert me.

Thanks

Pete

Does it burn your finger in about 1 second? its too hot. I think its around 140 150?

Sensor was giving a reading of 75c (168f) and was pretty hot, so I may have cooked the motor, so maybe setting a warning at 60c (140f) might be appropriate...

your thoughts?

temp reading on heat sink (clip on) may lower than actual on motor body,
so I think 60C is pretty safe number, regardless Brushed or Brushless motor,

though my Tamiya TZ 23T Stand Up stock motor which is best geared around 5.5 FDR would usually come from track about 75 C (still at good condition) ,

My general rule is to gear it to it smokes and then drop back a tooth. :lol: :lol: :lol:

In all seriousness, I follow the general rule that drew85 suggests, where if you can't hold your finger on the motor for 1.5 - 2 seconds then its probably too hot.

My Mrs uses mine after a race meet to cook the eggs for the kids that night.

I always check the color of the comm. If it turns purple, I know its too hot.

Thanks for your input Faiz, the sensor is installed inside the heatsink and does not have air flow over it, but yes I would expect it to be a few degrees lower. I have to pick an actual temp figure to input into the system, so maybe 60c will do until I figure out something else.

Comm is ok, the wind indicator (not sure what it is made of) is slightly burnt around the edges

Has anyone ever used an infra red temp sensor to measure the surface temp of a motor just after it has overheated and cooked itself?

98C with exergen, measured right away after 8 minutes race. Motor was Yokomo LT with 5 FDR, but did not check the color on the comm.

My motor was...was.....was...... :( :( :cry: :cry: :cry: 240 degrees imediately after it burned/smoked. I think something got caught up inside of it. It was running fine, when I rolled over a corner dot and suddenly went slower. As I pulled off of the track, holy smokes.

I've had motors go upto 181 degrees (not by choice) and still survive. At 210 degrees I noticed loss of power, comm was okay but magnets loss power. I think 145 is a safe temp to be at. Any time I loose power towards the end of a run, the motor has reached 160 or more. Hope this helps. :)

as long as the tag is the same white color after a run, the comm is is a nice copper, not orange, and the motor doesnt really fade i dont worry about motor temp. i gear for the point where it winds out on the straight about 3/4 the way down. i have had very fast stock motors in the 175*f range with little issue, and it wasnt detremental to the overall performance.

-Zac

Too hot is when the motor fades before 5 mins. Some people get hung up on temp, honestly it only applies in gas engines. You won't see any pros using temp guns on electric motors. If it makes it the full race without fade then who cares what the temp is.

P.S. High temps will kill the magnets quicker. That's one main reason you will see magnet zappers at major races.

yeah, the reason for the question was that the motor I was using was going well, and didnt just 'fade'. it completely stopped (at about 4 min), coming out of a corner it just stopped within a distance of 10m, no warning, middle of the track (car would not move at all), nothing was jammed in the motor, after it had cooled down it seems to work ok again :confused:

El hungo brusho?

Yeah I've had that happen to me before. The motor was way over geared and it got REALLY hot and just stopped until it cooled off then it ran again ok. The easiest way to tell the motor is getting too hot from overgearing is too look for discoloration on the com and brushes, that's a dead giveaway.